Antimicrobial Drug Resistance of Salmonella enterica Serovar Typhi in Asia and Molecular Mechanism of Reduced Susceptibility to the Fluoroquinolones▿

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Chau, Tran Thuy; Campbell, James Ian; Galindo, Claudia M.; Van Minh Hoang, Nguyen; Diep, To Song; Nga, Tran Thu Thi; Van Vinh Chau, Nguyen; Tuan, Phung Quoc; Page, Anne Laure; Ochiai, R. Leon; Schultsz, Constance; Wain, John; Bhutta, Zulfiqar A.; Parry, Christopher M.; Bhattacharya, Sujit K.

2007-01-01

This study describes the pattern and extent of drug resistance in 1,774 strains of Salmonella enterica serovar Typhi isolated across Asia between 1993 and 2005 and characterizes the molecular mechanisms underlying the reduced susceptibilities to fluoroquinolones of these strains. For 1,393 serovar Typhi strains collected in southern Vietnam, the proportion of multidrug resistance has remained high since 1993 (50% in 2004) and there was a dramatic increase in nalidixic acid resistance between ...

The Ecological Dynamics of Fecal Contamination and Salmonella Typhi and Salmonella Paratyphi A in Municipal Kathmandu Drinking Water

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Walker, Alan W.; Thompson, Corinne N.; Torres, Andres; Dongol, Sabina; Tran Vu Thieu, Nga; Pham Thanh, Duy; Tran Thi Ngoc, Dung; Voong Vinh, Phat; Singer, Andrew C.; Parkhill, Julian; Thwaites, Guy; Basnyat, Buddha; Ferguson, Neil; Baker, Stephen

2016-01-01

One of the UN sustainable development goals is to achieve universal access to safe and affordable drinking water by 2030. It is locations like Kathmandu, Nepal, a densely populated city in South Asia with endemic typhoid fever, where this goal is most pertinent. Aiming to understand the public health implications of water quality in Kathmandu we subjected weekly water samples from 10 sources for one year to a range of chemical and bacteriological analyses. We additionally aimed to detect the etiological agents of typhoid fever and longitudinally assess microbial diversity by 16S rRNA gene surveying. We found that the majority of water sources exhibited chemical and bacterial contamination exceeding WHO guidelines. Further analysis of the chemical and bacterial data indicated site-specific pollution, symptomatic of highly localized fecal contamination. Rainfall was found to be a key driver of this fecal contamination, correlating with nitrates and evidence of S. Typhi and S. Paratyphi A, for which DNA was detectable in 333 (77%) and 303 (70%) of 432 water samples, respectively. 16S rRNA gene surveying outlined a spectrum of fecal bacteria in the contaminated water, forming complex communities again displaying location-specific temporal signatures. Our data signify that the municipal water in Kathmandu is a predominant vehicle for the transmission of S. Typhi and S. Paratyphi A. This study represents the first extensive spatiotemporal investigation of water pollution in an endemic typhoid fever setting and implicates highly localized human waste as the major contributor to poor water quality in the Kathmandu Valley. PMID:26735696

The clinical and microbiological characteristics of enteric fever in Cambodia, 2008-2015.

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Laura M F Kuijpers

2017-09-01

Full Text Available Enteric fever remains a major public health problem in low resource settings and antibiotic resistance is increasing. In Asia, an increasing proportion of infections is caused by Salmonella enterica serovar Paratyphi A, which for a long time was assumed to cause a milder clinical syndrome compared to Salmonella enterica serovar Typhi.A retrospective chart review study was conducted of 254 unique cases of blood culture confirmed enteric fever who presented at a referral adult hospital in Phnom Penh, Cambodia between 2008 and 2015. Demographic, clinical and laboratory data were collected from clinical charts and antibiotic susceptibility testing was performed. Whole genome sequence analysis was performed on a subset of 121 isolates.One-hundred-and-ninety unique patients were diagnosed with Salmonella Paratyphi A and 64 with Salmonella Typhi. In the period 2008-2012, Salmonella Paratyphi A comprised 25.5% of 47 enteric fever cases compared to 86.0% of 207 cases during 2013-2015. Presenting symptoms were identical for both serovars but higher median leukocyte counts (6.8 x 109/L vs. 6.3 x 109/L; p = 0.035 and C-reactive protein (CRP values (47.0 mg/L vs. 36 mg/L; p = 0.034 were observed for Salmonella Typhi infections. All but one of the Salmonella Typhi isolates belonged to haplotype H58 associated with multidrug resistance (MDR (i.e. resistance to ampicillin, chloramphenicol and co-trimoxazole.;42.9% actually displayed MDR compared to none of the Salmonella Paratyphi A isolates. Decreased ciprofloxacin susceptibility (DCS was observed in 96.9% (62/64 of Salmonella Typhi isolates versus 11.5% (21/183 of Salmonella Paratyphi A isolates (all but one from 2015. All isolates were susceptible to azithromycin and ceftriaxone.In Phnom Penh, Cambodia, Salmonella Paratyphi A now causes the majority of enteric fever cases and decreased susceptibility against ciprofloxacin is increasing. Overall, Salmonella Typhi was significantly more associated with MDR and

Antimicrobial drug resistance of Salmonella enterica serovar typhi in asia and molecular mechanism of reduced susceptibility to the fluoroquinolones

NARCIS (Netherlands)

Chau, Tran Thuy; Campbell, James Ian; Galindo, Claudia M.; van Minh Hoang, Nguyen; Diep, To Song; Nga, Tran Thu Thi; van Vinh Chau, Nguyen; Tuan, Phung Quoc; Page, Anne Laure; Ochiai, R. Leon; Schultsz, Constance; Wain, John; Bhutta, Zulfiqar A.; Parry, Christopher M.; Bhattacharya, Sujit K.; Dutta, Shanta; Agtini, Magdarina; Dong, Baiqing; Honghui, Yang; Anh, Dang Duc; Canh, Do Gia; Naheed, Aliya; Albert, M. John; Phetsouvanh, Rattanaphone; Newton, Paul N.; Basnyat, Buddha; Arjyal, Amit; La, Tran Thi Phi; Rang, Nguyen Ngoc; Phuong, Le Thi; van Be Bay, Phan; von Seidlein, Lorenz; Dougan, Gordon; Clemens, John D.; Vinh, Ha; Hien, Tran Tinh; Chinh, Nguyen Tran; Acosta, Camilo J.; Farrar, Jeremy; Dolecek, Christiane

2007-01-01

This study describes the pattern and extent of drug resistance in 1,774 strains of Salmonella enterica serovar Typhi isolated across Asia between 1993 and 2005 and characterizes the molecular mechanisms underlying the reduced susceptibilities to fluoroquinolones of these strains. For 1,393 serovar

Differential Killing of Salmonella enterica Serovar Typhi by Antibodies Targeting Vi and Lipopolysaccharide O:9 Antigen.

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Peter J Hart

Full Text Available Salmonella enterica serovar Typhi expresses a capsule of Vi polysaccharide, while most Salmonella serovars, including S. Enteritidis and S. Typhimurium, do not. Both S. Typhi and S. Enteritidis express the lipopolysaccharide O:9 antigen, yet there is little evidence of cross-protection from anti-O:9 antibodies. Vaccines based on Vi polysaccharide have efficacy against typhoid fever, indicating that antibodies against Vi confer protection. Here we investigate the role of Vi capsule and antibodies against Vi and O:9 in antibody-dependent complement- and phagocyte-mediated killing of Salmonella. Using isogenic Vi-expressing and non-Vi-expressing derivatives of S. Typhi and S. Typhimurium, we show that S. Typhi is inherently more sensitive to serum and blood than S. Typhimurium. Vi expression confers increased resistance to both complement- and phagocyte-mediated modalities of antibody-dependent killing in human blood. The Vi capsule is associated with reduced C3 and C5b-9 deposition, and decreased overall antibody binding to S. Typhi. However, purified human anti-Vi antibodies in the presence of complement are able to kill Vi-expressing Salmonella, while killing by anti-O:9 antibodies is inversely related to Vi expression. Human serum depleted of antibodies to antigens other than Vi retains the ability to kill Vi-expressing bacteria. Our findings support a protective role for Vi capsule in preventing complement and phagocyte killing of Salmonella that can be overcome by specific anti-Vi antibodies, but only to a limited extent by anti-O:9 antibodies.

Differential Killing of Salmonella enterica Serovar Typhi by Antibodies Targeting Vi and Lipopolysaccharide O:9 Antigen.

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Hart, Peter J; O'Shaughnessy, Colette M; Siggins, Matthew K; Bobat, Saeeda; Kingsley, Robert A; Goulding, David A; Crump, John A; Reyburn, Hugh; Micoli, Francesca; Dougan, Gordon; Cunningham, Adam F; MacLennan, Calman A

2016-01-01

Salmonella enterica serovar Typhi expresses a capsule of Vi polysaccharide, while most Salmonella serovars, including S. Enteritidis and S. Typhimurium, do not. Both S. Typhi and S. Enteritidis express the lipopolysaccharide O:9 antigen, yet there is little evidence of cross-protection from anti-O:9 antibodies. Vaccines based on Vi polysaccharide have efficacy against typhoid fever, indicating that antibodies against Vi confer protection. Here we investigate the role of Vi capsule and antibodies against Vi and O:9 in antibody-dependent complement- and phagocyte-mediated killing of Salmonella. Using isogenic Vi-expressing and non-Vi-expressing derivatives of S. Typhi and S. Typhimurium, we show that S. Typhi is inherently more sensitive to serum and blood than S. Typhimurium. Vi expression confers increased resistance to both complement- and phagocyte-mediated modalities of antibody-dependent killing in human blood. The Vi capsule is associated with reduced C3 and C5b-9 deposition, and decreased overall antibody binding to S. Typhi. However, purified human anti-Vi antibodies in the presence of complement are able to kill Vi-expressing Salmonella, while killing by anti-O:9 antibodies is inversely related to Vi expression. Human serum depleted of antibodies to antigens other than Vi retains the ability to kill Vi-expressing bacteria. Our findings support a protective role for Vi capsule in preventing complement and phagocyte killing of Salmonella that can be overcome by specific anti-Vi antibodies, but only to a limited extent by anti-O:9 antibodies.

Salmonella typhi

OpenAIRE

Mochammad, Hatta

2008-01-01

This manuscript could use as research on infectious diseases Multi-locus variable-number tandem repeat analysis differentiated 297 Salmonella enterica serovar Typhi blood culture isolates from Makassar in 76 genotypes and a single unique S. Typhi genotype was isolated from the cholecystectomy specimens of four patients with cholelithiasis. The high diversity in S. Typhi genotypes circulating in Makassar indicates that the number of carriers could be very large, which may complicat...

Functional Analysis of the Chaperone-Usher Fimbrial Gene Clusters of Salmonella enterica serovar Typhi.

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Dufresne, Karine; Saulnier-Bellemare, Julie; Daigle, France

2018-01-01

The human-specific pathogen Salmonella enterica serovar Typhi causes typhoid, a major public health issue in developing countries. Several aspects of its pathogenesis are still poorly understood. S . Typhi possesses 14 fimbrial gene clusters including 12 chaperone-usher fimbriae ( stg, sth, bcf , fim, saf , sef , sta, stb, stc, std, ste , and tcf ). These fimbriae are weakly expressed in laboratory conditions and only a few are actually characterized. In this study, expression of all S . Typhi chaperone-usher fimbriae and their potential roles in pathogenesis such as interaction with host cells, motility, or biofilm formation were assessed. All S . Typhi fimbriae were better expressed in minimal broth. Each system was overexpressed and only the fimbrial gene clusters without pseudogenes demonstrated a putative major subunits of about 17 kDa on SDS-PAGE. Six of these (Fim, Saf, Sta, Stb, Std, and Tcf) also show extracellular structure by electron microscopy. The impact of fimbrial deletion in a wild-type strain or addition of each individual fimbrial system to an S . Typhi afimbrial strain were tested for interactions with host cells, biofilm formation and motility. Several fimbriae modified bacterial interactions with human cells (THP-1 and INT-407) and biofilm formation. However, only Fim fimbriae had a deleterious effect on motility when overexpressed. Overall, chaperone-usher fimbriae seem to be an important part of the balance between the different steps (motility, adhesion, host invasion and persistence) of S . Typhi pathogenesis.

Multi-locus variable-number tandem repeat profiling of Salmonella enterica serovar Typhi isolates from blood cultures and gallbladder specimens from Makassar, South-Sulawesi, Indonesia.

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Mochammad Hatta

Full Text Available Multi-locus variable-number tandem repeat analysis differentiated 297 Salmonella enterica serovar Typhi blood culture isolates from Makassar in 76 genotypes and a single unique S. Typhi genotype was isolated from the cholecystectomy specimens of four patients with cholelithiasis. The high diversity in S. Typhi genotypes circulating in Makassar indicates that the number of carriers could be very large, which may complicate disease prevention and control.

Role of Environmental Factors in Shaping Spatial Distribution of Salmonella enterica Serovar Typhi, Fiji.

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de Alwis, Ruklanthi; Watson, Conall; Nikolay, Birgit; Lowry, John H; Thieu, Nga Tran Vu; Van, Tan Trinh; Ngoc, Dung Tran Thi; Rawalai, Kitione; Taufa, Mere; Coriakula, Jerimaia; Lau, Colleen L; Nilles, Eric J; Edmunds, W John; Kama, Mike; Baker, Stephen; Cano, Jorge

2018-02-01

Fiji recently experienced a sharp increase in reported typhoid fever cases. To investigate geographic distribution and environmental risk factors associated with Salmonella enterica serovar Typhi infection, we conducted a cross-sectional cluster survey with associated serologic testing for Vi capsular antigen-specific antibodies (a marker for exposure to Salmonella Typhi in Fiji in 2013. Hotspots with high seroprevalence of Vi-specific antibodies were identified in northeastern mainland Fiji. Risk for Vi seropositivity increased with increased annual rainfall (odds ratio [OR] 1.26/quintile increase, 95% CI 1.12-1.42), and decreased with increased distance from major rivers and creeks (OR 0.89/km increase, 95% CI 0.80-0.99) and distance to modeled flood-risk areas (OR 0.80/quintile increase, 95% CI 0.69-0.92) after being adjusted for age, typhoid fever vaccination, and home toilet type. Risk for exposure to Salmonella Typhi and its spatial distribution in Fiji are driven by environmental factors. Our findings can directly affect typhoid fever control efforts in Fiji.

Challenge of Humans with Wild-type Salmonella enterica Serovar Typhi Elicits Changes in the Activation and Homing Characteristics of Mucosal-Associated Invariant T Cells

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Salerno-Goncalves, Ros?ngela; Luo, David; Fresnay, Stephanie; Magder, Laurence; Darton, Thomas C.; Jones, Claire; Waddington, Claire S.; Blohmke, Christoph J.; Angus, Brian; Levine, Myron M.; Pollard, Andrew J.; Sztein, Marcelo B.

2017-01-01

Gastrointestinal infections by Salmonella enterica serovar Typhi (S. Typhi) are rare in industrialized countries. However, they remain a major public health problem in the developing world with an estimated 26.9 million new cases annually and significant mortality when untreated. Recently, we provided the first direct evidence that CD8(+) MAIT cells are activated and have the potential to kill cells exposed to S. Typhi, and that these responses are dependent on bacterial load. However, MAIT c...

Antibiotic Resistance of Salmonella enterica Serovar Typhi in Kolkata, India, and In Vitro Experiments on Effect of Combined Chemotherapy

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Shyamapada Mandal

2012-01-01

Full Text Available This communication states the changing patterns of Salmonella enterica serovar Typhi (S. Typhi isolates causing enteric fever in and around Kolkata, India. Among the isolates resistance to ampicillin (A, chloramphenicol (C, cotrimoxazole (Co and tetracycline (T were plasmid mediated; the plasmid was unstable in S. Typhi, and the other enteric bacteria like Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris were found to be the potential source of dissemination of such plasmids into S. Typhi. The infection with such S. Typhi strains were successfully treated with ciprofloxacin (Cp: MICs 0.0075–0.075 μg mL−1 and/or ofloxacin (Ofx: MICs 0.0125–0.075 μg mL−1, but in the later course, the S. Typhi strains, showing resistance to nalidixic acid, developed low level of resistance to Cp and Ofx, causing the treatment failure. Thus, the treatment regimen was shifted to the third generation cephalosporins like ceftriaxone (Ct and cefotaxime (Cf. Keeping in mind the anticipation of development of resistance to Ct/Cf, we prepared the treatment regimen for MDR enteric fever, based on the double-drug synergy tests in vitro; Cp-gentamycin (FICI 0.121–0.216 and Cp-trimethoprim (FICI 0.14–0.483 combinations were found effective against S. Typhi isolates having decreased sensitivity to cp (MICs: 0.5–1.25 μg mL−1.

Genomic Dissection of Travel-Associated Extended-Spectrum-Beta-Lactamase-Producing Salmonella enterica Serovar Typhi Isolates Originating from the Philippines: a One-Off Occurrence or a Threat to Effective Treatment of Typhoid Fever?

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Hendriksen, Rene S.; Leekitcharoenphon, Pimlapas; Mikoleit, Matthew

2015-01-01

One unreported case of extended-spectrum-beta-lactamase (ESBL)-producing Salmonella enterica serovar Typhi was identified, whole-genome sequence typed, among other analyses, and compared to other available genomes of S. Typhi. The reported strain was similar to a previously published strain harbo...

Treatment failure in a typhoid patient infected with nalidixic acid resistant S. enterica serovar Typhi with reduced susceptibility to Ciprofloxacin: a case report from Cameroon

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Asonganyi Etienne DN

2005-06-01

Full Text Available Abstract Background Fluoroquinolones or third generation cephalosporins are the drugs of choice for the treatment of typhoid fever. Treatment failure with fluoroquinolones has been reported in Asia and Europe. We report a case of ciprofloxacin treatment failure in typhoid fever in Cameroon. Case presentation A 29-year-old female patient with suspected typhoid fever from Kumba, Cameroon, yielded growth of Salmonella enterica serovar Typhi in blood culture. The isolate was resistant to nalidixic acid but sensitive to ciprofloxacin by disc diffusion test. However, the patient did not respond to treatment with ciprofloxacin, although the isolate was apparently susceptible to ciprofloxacin. Conclusion Treatment failure with ciprofloxacin in our case indicates the presence of nalidixic acid resistant S. enterica serovar Typhi (NARST with reduced susceptibility to ciprofloxacin in Cameroon (Central Africa.

Isolation of Salmonella paratyphi A from renal abscess

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D'Cruz Sanjay

2009-01-01

Full Text Available Intrarenal abscesses remain a significant cause of morbidity and mortality as well as a diagnostic dilemma because a plethora of microorganisms can cause this condition. A definitive diagnosis is made by demonstrating the organisms from the aspirate and the success or failure of therapy depends upon the antimicrobial sensitivity pattern. Enteric fever is a multisystem disorder caused by invasive strains of salmonella. Salmonellosis continues to be a major public health problem, especially in developing countries. Classic enteric fever is caused by S. typhi and usually less severe enteric fevers are caused by S. paratyphi A, B, or C. However, at times S. paratyphi is capable of causing serious and often life-threatening infections like infective endocarditis, pericarditis, empyma, sino-venous thrombosis, osteomyelitis, meningitis, bone marrow infiltration, hepatitis and pancreatitis. There are anecdotal case reports in world literature of abscesses being caused by this organism. Renal involvement like bacteriuria, nephrotic syndrome and acute renal failure have been reported due to S. parayphi A. S. paratyphi A has never been implicated in renal abscess, we report one such case that was managed successfully with medical therapy.

Variable Responses to Carbon Utilization between Planktonic and Biofilm Cells of a Human Carrier Strain of Salmonella enterica Serovar Typhi.

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Kalaivani Kalai Chelvam

Full Text Available Salmonella enterica serovar Typhi (S. Typhi is a foodborne pathogen that causes typhoid fever and infects only humans. The ability of S. Typhi to survive outside the human host remains unclear, particularly in human carrier strains. In this study, we have investigated the catabolic activity of a human carrier S. Typhi strain in both planktonic and biofilm cells using the high-throughput Biolog Phenotype MicroArray, Minimum Biofilm Eradication Concentration (MBEC biofilm inoculator (96-well peg lid and whole genome sequence data. Additional strains of S. Typhi were tested to further validate the variation of catabolism in selected carbon substrates in the different bacterial growth phases. The analyzes of the carbon utilization data indicated that planktonic cells of the carrier strain, S. Typhi CR0044 could utilize a broader range of carbon substrates compared to biofilm cells. Pyruvic acid and succinic acid which are related to energy metabolism were actively catabolised in the planktonic stage compared to biofilm stage. On the other hand, glycerol, L-fucose, L-rhamnose (carbohydrates and D-threonine (amino acid were more actively catabolised by biofilm cells compared to planktonic cells. Notably, dextrin and pectin could induce strong biofilm formation in the human carrier strain of S. Typhi. However, pectin could not induce formation of biofilm in the other S. Typhi strains. Phenome data showed the utilization of certain carbon substrates which was supported by the presence of the catabolism-associated genes in S. Typhi CR0044. In conclusion, the findings showed the differential carbon utilization between planktonic and biofilm cells of a S. Typhi human carrier strain. The differences found in the carbon utilization profiles suggested that S. Typhi uses substrates mainly found in the human biliary mucus glycoprotein, gallbladder, liver and cortex of the kidney of the human host. The observed diversity in the carbon catabolism profiles among

Case report: failure under azithromycin treatment in a case of bacteremia due to Salmonella enterica Paratyphi A.

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Kobayashi, Tetsuro; Hayakawa, Kayoko; Mawatari, Momoko; Mezaki, Kazuhisa; Takeshita, Nozomi; Kutsuna, Satoshi; Fujiya, Yoshihiro; Kanagawa, Shuzo; Ohmagari, Norio; Kato, Yasuyuki; Morita, Masatomo

2014-07-20

Limited information is available regarding the clinical efficacy of azithromycin for the treatment of enteric fever due to fluoroquinolone-resistant Salmonella Typhi and Salmonella Paratyphi among travelers returning to their home countries. We report a case of a 52-year-old Japanese man who returned from India, who developed a fever of 39°C with no accompanying symptoms 10 days after returning to Japan from a 1-month business trip to Delhi, India. His blood culture results were positive for Salmonella Paratyphi A. He was treated with 14 days of ceftriaxone, after which he remained afebrile for 18 days before his body temperature again rose to 39°C with no apparent symptoms. He was then empirically given 500 mg of azithromycin, but experienced clinical and microbiological failure of azithromycin treatment for enteric fever due to Salmonella Paratyphi A. However, the minimum inhibitory concentration (MIC) of azithromycin was not elevated (8 mg/L). He was again given ceftriaxone for 14 days with no signs of recurrence during the follow-up. There are limited data available for the treatment of enteric fever using azithromycin in travelers from developed countries who are not immune to the disease, and thus, careful follow-up is necessary. In our case, the low azithromycin dose might have contributed the treatment failure. Additional clinical data are needed to determine the rate of success, MIC, and contributing factors for success and/or failure of azithromycin treatment for both Salmonella Typhi and Salmonella Paratyphi infections.

Typhoid fever

DEFF Research Database (Denmark)

Wain, John; Hendriksen, Rene S.; Mikoleit, Matthew L.

2015-01-01

Control of typhoid fever relies on clinical information, diagnosis, and an understanding for the epidemiology of the disease. Despite the breadth of work done so far, much is not known about the biology of this human-adapted bacterial pathogen and the complexity of the disease in endemic areas...... with shifting trends in enteric fever. This knowledge is crucial, both to control the disease and to manage cases. Additionally, salmonella serovars that cause human infection can change over time and location. In areas of Asia, multidrug-resistant Salmonella enterica serovar Typhi (S Typhi) has been the main...... cause of enteric fever, but now S Typhi is being displaced by infections with drug-resistant S enterica serovar Paratyphi A. New conjugate vaccines are imminent and new treatments have been promised, but the engagement of local medical and public health institutions in endemic areas is needed to allow...

A 3' UTR-derived non-coding RNA RibS increases expression of cfa and promotes biofilm formation of Salmonella enterica serovar Typhi.

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Zhao, Xin; Liu, Rui; Tang, Hao; Osei-Adjei, George; Xu, Shungao; Zhang, Ying; Huang, Xinxiang

2018-05-08

Bacterial non-coding RNAs (ncRNAs) are widely studied and found to play important roles in regulating various cellular processes. Recently, many ncRNAs have been discovered to be transcribed or processed from 3' untranslated regions (3' UTRs). Here we reported a novel 3' UTR-derived ncRNA, RibS, which could influence biofilm formation of Salmonella enterica serovar Typhi (S. Typhi). RibS was confirmed to be a ∼700 nt processed product produced by RNase III-catalyzed cleavage from the 3' UTR of riboflavin synthase subunit alpha mRNA, RibE. Overexpression of RibS increased the expression of the cyclopropane fatty acid synthase gene, cfa, which was located at the antisense strand. Biofilm formation of S. Typhi was enhanced by overexpressing RibS both in the wild type strain and cfa deletion mutant. Deletion of cfa attenuated biofilm formation of S. Typhi, while complementation of cfa partly restored the phenotype. Moreover, overexpressing cfa enhanced the biofilm formation of S. Typhi. In summary, RibS has been identified as a novel ncRNA derived from the 3' UTR of RibE that promotes biofilm formation of S. Typhi, and it appears to do so, at least in part, by increasing the expression of cfa. Copyright © 2018 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Vaccines against invasive Salmonella disease

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MacLennan, Calman A; Martin, Laura B; Micoli, Francesca

2014-01-01

Though primarily enteric pathogens, Salmonellae are responsible for a considerable yet under-appreciated global burden of invasive disease. In South and South-East Asia, this manifests as enteric fever caused by serovars Typhi and Paratyphi A. In sub-Saharan Africa, a similar disease burden results from invasive nontyphoidal Salmonellae, principally serovars Typhimurium and Enteritidis. The existing Ty21a live-attenuated and Vi capsular polysaccharide vaccines target S. Typhi and are not effective in young children where the burden of invasive Salmonella disease is highest. After years of lack of investment in new Salmonella vaccines, recent times have seen increased interest in the area led by emerging-market manufacturers, global health vaccine institutes and academic partners. New glycoconjugate vaccines against S. Typhi are becoming available with similar vaccines against other invasive serovars in development. With other new vaccines under investigation, including live-attenuated, protein-based and GMMA vaccines, now is an exciting time for the Salmonella vaccine field. PMID:24804797

Salmonella enterica serovar-specific transcriptional reprogramming of infected cells.

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Hannemann, Sebastian; Galán, Jorge E

2017-07-01

Despite their high degree of genomic similarity, different Salmonella enterica serovars are often associated with very different clinical presentations. In humans, for example, the typhoidal S. enterica serovar Typhi causes typhoid fever, a life-threatening systemic disease. In contrast, the non-typhoidal S. enterica serovar Typhimurium causes self-limiting gastroenteritis. The molecular bases for these different clinical presentations are incompletely understood. The ability to re-program gene expression in host cells is an essential virulence factor for typhoidal and non-typhoidal S. enterica serovars. Here, we have compared the transcriptional profile of cultured epithelial cells infected with S. Typhimurium or S. Typhi. We found that both serovars stimulated distinct transcriptional responses in infected cells that are associated with the stimulation of specific signal transduction pathways. These specific responses were associated with the presence of a distinct repertoire of type III secretion effector proteins. These observations provide major insight into the molecular bases for potential differences in the pathogenic mechanisms of typhoidal and non-typhoidal S. enterica serovars.

Estimating the burden of paratyphoid a in Asia and Africa.

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Michael B Arndt

2014-06-01

Full Text Available Despite the increasing availability of typhoid vaccine in many regions, global estimates of mortality attributable to enteric fever appear stable. While both Salmonella enterica serovar Typhi (S. Typhi and serovar Paratyphi (S. Paratyphi cause enteric fever, limited data exist estimating the burden of S. Paratyphi, particularly in Asia and Africa. We performed a systematic review of both English and Chinese-language databases to estimate the regional burden of paratyphoid within Africa and Asia. Distinct from previous reviews of the topic, we have presented two separate measures of burden; both incidence and proportion of enteric fever attributable to paratyphoid. Included articles reported laboratory-confirmed Salmonella serovar classification, provided clear methods on sampling strategy, defined the age range of participants, and specified the time period of the study. A total of 64 full-text articles satisfied inclusion criteria and were included in the qualitative synthesis. Paratyphoid A was commonly identified as a cause of enteric fever throughout Asia. The highest incidence estimates in Asia came from China; four studies estimated incidence rates of over 150 cases/100,000 person-years. Paratyphoid A burden estimates from Africa were extremely limited and with the exception of Nigeria, few population or hospital-based studies from Africa reported significant Paratyphoid A burden. While significant gaps exist in the existing population-level estimates of paratyphoid burden in Asia and Africa, available data suggest that paratyphoid A is a significant cause of enteric fever in Asia. The high variability in documented incidence and proportion estimates of paratyphoid suggest considerable geospatial variability in the burden of paratyphoid fever. Additional efforts to monitor enteric fever at the population level will be necessary in order to accurately quantify the public health threat posed by S. Paratyphi A, and to improve the prevention

Simple dipstick assay for the detection of Salmonella typhi-specific IgM antibodies and the evolution of the immune response in patients with typhoid fever

NARCIS (Netherlands)

Hatta, Mochammad; Goris, Marga G. A.; Heerkens, Evy; Gooskens, Jairo; Smits, Henk L.

2002-01-01

Application of a dipstick assay for the detection of Salmonella typhi-specific IgM antibodies on samples collected from S. typhi or S. paratyphi culture-positive patients at the day of admission to the hospital revealed the presence of specific IgM antibodies in 43.5%, 92.9%, and 100% for samples

Salmonella enterica serovar-specific transcriptional reprogramming of infected cells.

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Sebastian Hannemann

2017-07-01

Full Text Available Despite their high degree of genomic similarity, different Salmonella enterica serovars are often associated with very different clinical presentations. In humans, for example, the typhoidal S. enterica serovar Typhi causes typhoid fever, a life-threatening systemic disease. In contrast, the non-typhoidal S. enterica serovar Typhimurium causes self-limiting gastroenteritis. The molecular bases for these different clinical presentations are incompletely understood. The ability to re-program gene expression in host cells is an essential virulence factor for typhoidal and non-typhoidal S. enterica serovars. Here, we have compared the transcriptional profile of cultured epithelial cells infected with S. Typhimurium or S. Typhi. We found that both serovars stimulated distinct transcriptional responses in infected cells that are associated with the stimulation of specific signal transduction pathways. These specific responses were associated with the presence of a distinct repertoire of type III secretion effector proteins. These observations provide major insight into the molecular bases for potential differences in the pathogenic mechanisms of typhoidal and non-typhoidal S. enterica serovars.

Optimization of randomly amplified polymorphic DNA-polymerase chain reaction for molecular typing of Salmonella enterica serovar Typhi Otimização da reação de amplificação aleatória do DNA polimórfico - reação em cadeia da polimerase para tipagem molecular de Salmonella enterica sorovar Typhi

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Bianca Ramalho Quintaes

2004-03-01

Full Text Available Optimization of the RAPD reaction for characterizing Salmonella enterica serovar Typhi strains was studied in order to ensure the reproducibility and the discriminatory power of this technique. Eight Salmonella serovar Typhi strains isolated from various regions in Brazil were examined for the fragment patterns produced using different concentrations of DNA template, primer, MgCl2 and Taq DNA polymerase. Using two different low stringency thermal cycle profiles, the RAPD fingerprints obtained were compared. A set of sixteen primers was evaluated for their ability to produce a high number of distinct fragments. We found that variations associated to all of the tested parameters modified the fingerprinting patterns. For the strains of Salmonella enterica serovar Typhi used in this experiment, we have defined a set of conditions for RAPD-PCR reaction, which result in a simple, fast and reproducible typing method.A otimização da reação de RAPD para a caracterização de cepas de Salmonella enterica sorovar Typhi foi estudada com o objetivo de assegurar a reprodutibilidade e o poder discriminatório desta técnica. Oito cepas de Salmonella sorovar Typhi isoladas de algumas regiões do Brasil foram usadas para examinar os padrões de fragmentação produzidos quando foram empregadas concentrações diferentes do DNA molde, do iniciador, do MgCl2 e da enzima Taq DNA polimerase. Com a utilização de dois diferentes perfis de ciclos termais de baixa estringência, foram comparados os padrões de bandeamento obtidos. Um conjunto de dezesseis iniciadores foi avaliado quanto à capacidade de produzir elevado número de fragmentos distintos. Observou-se que variações associadas a todos os parâmetros testados modificaram os padrões de bandeamento. Para as amostras de Salmonella enterica sorovar Typhi utilizadas neste experimento, definiu-se um conjunto de condições para a reação de RAPD-PCR que resultou num método de tipagem simples, rápido e

Modified intracellular-associated phenotypes in a recombinant Salmonella Typhi expressing S. Typhimurium SPI-3 sequences.

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Patricio Retamal

Full Text Available A bioinformatics comparison of Salmonella Pathogenicity Island 3 sequences from S. Typhi and S. Typhimurium serovars showed that ten genes are highly conserved. However three of them are pseudogenes in S. Typhi. Our aim was to understand what functions are lost in S. Typhi due to pseudogenes by constructing a S. Typhi genetic hybrid carrying the SPI-3 region of S. Typhimurium instead of its own SPI-3. We observed that under stressful conditions the hybrid strain showed a clear impairment in resistance to hydrogen peroxide and decreased survival within U937 culture monocytes. We hypothesized that the marT-fidL operon, encoded in SPI-3, was responsible for the new phenotypes because marT is a pseudogen in S. Typhi and has a demonstrated role as a transcriptional regulator in S. Typhimurium. Therefore we cloned and transferred the S. Typhimurium marT-fidL operon into S. Typhi and confirmed that invasion of monocytes was dramatically decreased. Finally, our findings suggest that the genomic and functional differences between SPI-3 sequences have implications in the host specificity of Typhi and Typhimurium serovars.

Quinolone resistance in Salmonella enterica serovar Typhi ...

African Journals Online (AJOL)

Typhi is the major cause of typhoid fever (or enteric fever), a characteristic severe ... fluorine atom and a cyclic diamine piperazine at C6 and. C7 positions of the .... access to clean and safe water, adequate sanitation, and education should be ...

Genomic Signature of Multidrug-Resistant Salmonella enterica Serovar Typhi Isolates Related to a Massive Outbreak in Zambia between 2010 and 2012

DEFF Research Database (Denmark)

Hendriksen, Rene S.; Leekitcharoenphon, Pimlapas; Lukjancenko, Oksana

2015-01-01

). The isolates belonged to MLST ST1 and a new variant of the haplotype, H58B. Most isolates contained a chromosomally translocated region containing seven antimicrobial resistance genes, catA1, blaTEM-1, dfrA7, sul1, sul2, strA, and strB, and fragments of the incompatibility group Q1 (IncQ1) plasmid replicon......Retrospectively, we investigated the epidemiology of a massive Salmonella enterica serovar Typhi outbreak in Zambia during 2010 to 2012. Ninety-four isolates were susceptibility tested by MIC determinations. Whole-genome sequence typing (WGST) of 33 isolates and bioinformatic analysis identified...

The Development and Evaluation of a Loop-Mediated Isothermal Amplification Method for the Rapid Detection of Salmonella enterica serovar Typhi.

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Fenxia Fan

Full Text Available Typhoid fever remains a public health threat in many countries. A positive result in traditional culture is a gold-standard for typhoid diagnosis, but this method is time consuming and not sensitive enough for detection of samples containing a low copy number of the target organism. The availability of the loop-mediated isothermal amplification (LAMP assay, which offers high speed and simplicity in detection of specific targets, has vastly improved the diagnosis of numerous infectious diseases. However, little research efforts have been made on utilizing this approach for diagnosis of Salmonella enterica serovar Typhi by targeting a single and specific gene. In this study, a LAMP assay for rapid detection of S. Typhi based on a novel marker gene, termed STY2879-LAMP, was established and evaluated with real-time PCR (RT-PCR. The specificity tests showed that STY2879 could be amplified in all S. Typhi strains isolated in different years and regions in China, whereas no amplification was observable in non-typhoidal strains covering 34 Salmonella serotypes and other pathogens causing febrile illness. The detection limit of STY2879-LAMP for S. Typhi was 15 copies/reaction in reference plasmids, 200 CFU/g with simple heat-treatment of DNA extracted from simulated stool samples and 20 CFU/ml with DNA extracted from simulated blood samples, which was 10 fold more sensitive than the parallel RT-PCR control experiment. Furthermore, the sensitivity of STY2879-LAMP and RT-PCR combining the traditional culture enrichment method for simulated stool and blood spiked with lower S. Typhi count during the 10 h enrichment time was also determined. In comparison with LAMP, the positive reaction time for RT-PCR required additional 2-3 h enrichment time for either simulated stool or blood specimens. Therefore, STY2879-LAMP is of practical value in the clinical settings and has a good potential for application in developing regions due to its easy-to-use protocol.

Salmonella Typhi sense host neuroendocrine stress hormones and release the toxin haemolysin E

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Karavolos, Michail H; Bulmer, David M; Spencer, Hannah; Rampioni, Giordano; Schmalen, Ira; Baker, Stephen; Pickard, Derek; Gray, Joe; Fookes, Maria; Winzer, Klaus; Ivens, Alasdair; Dougan, Gordon; Williams, Paul; Khan, C M Anjam

2011-01-01

Salmonella enterica serovar Typhi (S. typhi) causes typhoid fever. We show that exposure of S. typhi to neuroendocrine stress hormones results in haemolysis, which is associated with the release of haemolysin E in membrane vesicles. This effect is attributed to increased expression of the small RNA micA and RNA chaperone Hfq, with concomitant downregulation of outer membrane protein A. Deletion of micA or the two-component signal-transduction system, CpxAR, abolishes the phenotype. The hormone response is inhibited by the β-blocker propranolol. We provide mechanistic insights into the basis of neuroendocrine hormone-mediated haemolysis by S. typhi, increasing our understanding of inter-kingdom signalling. PMID:21331094

Stochastic simulation of endemic Salmonella enterica serovar Typhi: the importance of long lasting immunity and the carrier state.

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Allan Saul

Full Text Available BACKGROUND: Typhoid fever caused by Salmonella enterica serovar Typhi (S. Typhi remains a serious burden of disease, especially in developing countries of Asia and Africa. It is estimated that it causes 200,000 deaths per year, mainly in children. S. Typhi is an obligate pathogen of humans and although it has a relatively complex life cycle with a long lived carrier state, the absence of non-human hosts suggests that well targeted control methods should have a major impact on disease. Newer control methods including new generations of vaccines offer hope but their implementation would benefit from quantitative models to guide the most cost effective strategies. This paper presents a quantitative model of Typhoid disease, immunity and transmission as a first step in that process. METHODOLOGY/PRINCIPAL FINDINGS: A stochastic agent-based model has been developed that incorporates known features of the biology of typhoid including probability of infection, the consequences of infection, treatment options, acquisition and loss of immunity as a result of infection and vaccination, the development of the carrier state and the impact of environmental or behavioral factors on transmission. The model has been parameterized with values derived where possible from the literature and where this was not possible, feasible parameters space has been determined by sensitivity analyses, fitting the simulations to age distribution of field data. The model is able to adequately predict the age distribution of typhoid in two settings. CONCLUSIONS/SIGNIFICANCE: The modeling highlights the importance of variations in the exposure/resistance of infants and young children to infection in different settings, especially as this impacts on design of control programs; it predicts that naturally induced clinical and sterile immunity to typhoid is long lived and highlights the importance of the carrier state especially in areas of low transmission.

Salmonella Typhi genomics: envisaging the future of typhoid eradication.

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Yap, Kien-Pong; Thong, Kwai Lin

2017-08-01

Next-generation whole-genome sequencing has revolutionised the study of infectious diseases in recent years. The availability of genome sequences and its understanding have transformed the field of molecular microbiology, epidemiology, infection treatments and vaccine developments. We review the key findings of the publicly accessible genomes of Salmonella enterica serovar Typhi since the first complete genome to the most recent release of thousands of Salmonella Typhi genomes, which remarkably shape the genomic research of S. Typhi and other pathogens. Important new insights acquired from the genome sequencing of S. Typhi, pertaining to genomic variations, evolution, population structure, antibiotic resistance, virulence, pathogenesis, disease surveillance/investigation and disease control are discussed. As the numbers of sequenced genomes are increasing at an unprecedented rate, fine variations in the gene pool of S. Typhi are captured in high resolution, allowing deeper understanding of the pathogen's evolutionary trends and its pathogenesis, paving the way to bringing us closer to eradication of typhoid through effective vaccine/treatment development. © 2017 John Wiley & Sons Ltd.

Compositional and Functional Differences in the Human Gut Microbiome Correlate with Clinical Outcome following Infection with Wild-Type Salmonella enterica Serovar Typhi.

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Zhang, Yan; Brady, Arthur; Jones, Cheron; Song, Yang; Darton, Thomas C; Jones, Claire; Blohmke, Christoph J; Pollard, Andrew J; Magder, Laurence S; Fasano, Alessio; Sztein, Marcelo B; Fraser, Claire M

2018-05-08

Insights into disease susceptibility as well as the efficacy of vaccines against typhoid and other enteric pathogens may be informed by better understanding the relationship between the effector immune response and the gut microbiota. In the present study, we characterized the composition (16S rRNA gene profiling) and function (RNA sequencing [RNA-seq]) of the gut microbiota following immunization and subsequent exposure to wild-type Salmonella enterica serovar Typhi in a human challenge model to further investigate the central hypothesis that clinical outcomes may be linked to the gut microbiota. Metatranscriptome analysis of longitudinal stool samples collected from study subjects revealed two stable patterns of gene expression for the human gut microbiota, dominated by transcripts from either Methanobrevibacter or a diverse representation of genera in the Firmicutes phylum. Immunization with one of two live oral attenuated vaccines against S.  Typhi had minimal effects on the composition or function of the gut microbiota. It was observed that subjects harboring the methanogen-dominated transcriptome community at baseline displayed a lower risk of developing symptoms of typhoid following challenge with wild-type S.  Typhi. Furthermore, genes encoding antioxidant proteins, metal homeostasis and transport proteins, and heat shock proteins were expressed at a higher level at baseline or after challenge with S.  Typhi in subjects who did not develop symptoms of typhoid. These data suggest that functional differences relating to redox potential and ion homeostasis in the gut microbiota may impact clinical outcomes following exposure to wild-type S.  Typhi. IMPORTANCE S.  Typhi is a significant cause of systemic febrile morbidity in settings with poor sanitation and limited access to clean water. It has been demonstrated that the human gut microbiota can influence mucosal immune responses, but there is little information available on the impact of the human gut

Antimicrobial resistance in Salmonella spp. recovered from patients admitted to six different hospitals in Tehran, Iran from 2007 to 2008

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Tajbakhsh, Mercedeh; Hendriksen, Rene S.; Nochi, Zahra

2012-01-01

were screened for the presence of Salmonella, serotyped, tested for antimicrobial susceptibility using disk diffusion and examined for the presence of relevant resistance genes and integrons by PCR. A total of 1,120 patients were screened for the presence of Salmonella. Out of 71 Salmonella isolates...... recovered, the following serovars were identified: 17 Typhi, 14 Paratyphi C, 13 Enteritidis, 11 Paratyphi B, 10 Paratyphi A and six Infantis. Most resistance was observed towards sulfamethoxazole (30%), tetracyclines (25%), nalidixic acid (22%), spectinomycin (17%), trimethoprim (15%), ampicillin (14......%) and kanamycin (14%). The tetracycline resistance genes tet(A), tet(B), and tet(G) were found in 28%, 14% and 6% of the tetracycline resistant isolates, respectively. The genes aadA, aadB, strA, strB and aphA1-Iab were present in 83%, 55%, 34%, 1% and 17% of the aminoglycoside resistant isolates, respectively...

Cell-associated flagella enhance the protection conferred by mucosally-administered attenuated Salmonella Paratyphi A vaccines.

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Orit Gat

2011-11-01

Full Text Available Antibiotic-resistant Salmonella enterica serovar Paratyphi A, the agent of paratyphoid A fever, poses an emerging public health dilemma in endemic areas of Asia and among travelers, as there is no licensed vaccine. Integral to our efforts to develop a S. Paratyphi A vaccine, we addressed the role of flagella as a potential protective antigen by comparing cell-associated flagella with exported flagellin subunits expressed by attenuated strains.S. Paratyphi A strain ATCC 9150 was first deleted for the chromosomal guaBA locus, creating CVD 1901. Further chromosomal deletions in fliD (CVD 1901D or flgK (CVD 1901K were then engineered, resulting in the export of unpolymerized FliC, without impairing its overall expression. The virulence of the resulting isogenic strains was examined using a novel mouse LD(50 model to accommodate the human-host restricted S. Paratyphi A. The immunogenicity of the attenuated strains was then tested using a mouse intranasal model, followed by intraperitoneal challenge with wildtype ATCC 9150.Mucosal (intranasal immunization of mice with strain CVD 1901 expressing cell-associated flagella conferred superior protection (vaccine efficacy [VE], 90% against a lethal intraperitoneal challenge, compared with the flagellin monomer-exporting mutants CVD 1901K (30% VE or CVD 1901D (47% VE. The superior protection induced by CVD 1901 with its cell-attached flagella was associated with an increased IgG2a:IgG1 ratio of FliC-specific antibodies with enhanced opsonophagocytic capacity.Our results clearly suggest that enhanced anti-FliC antibody-mediated clearance of S. Paratyphi A by phagocytic cells, induced by vaccines expressing cell-associated rather than exported FliC, might be contributing to the vaccine-induced protection from S. Paratyphi A challenge in vivo. We speculate that an excess of IgG1 anti-FliC antibodies induced by the exported FliC may compete with the IgG2a subtype and block binding to specific phagocyte Fc

The discrimination of d-tartrate positive and d-tartrate negative S. enterica subsp. enterica serovar Paratyphi B isolated in Malaysia by phenotypic and genotypic methods.

Science.gov (United States)

Ahmad, Norazah; Hoon, Shirley Tang Gee; Ghani, Mohamed Kamel Abd; Tee, Koh Yin

2012-06-01

Serotyping is not sufficient to differentiate between Salmonella species that cause paratyphoid fever from the strains that cause milder gastroenteritis as these organisms share the same serotype Salmonella Paratyphi B (S. Paratyphi B). Strains causing paratyphoid fever do not ferment d-tartrate and this key feature was used in this study to determine the prevalence of these strains among the collection of S. Paratyphi B strains isolated from patients in Malaysia. A total of 105 isolates of S. Paratyphi B were discriminated into d-tartrate positive (dT+) and d-tartrate negative (dT) variants by two lead acetate test protocols and multiplex PCR. The lead acetate test protocol 1 differed from protocol 2 by a lower inoculum size and different incubation conditions while the multiplex PCR utilized 2 sets of primers targeting the ATG start codon of the gene STM3356. Lead acetate protocol 1 discriminated 97.1% of the isolates as S. Paratyphi B dT+ and 2.9% as dT while test protocol 2 discriminated all the isolates as S. Paratyphi B dT+. The multiplex PCR test identified all 105 isolates as S. Paratyphi B dT+ strains. The concordance of the lead acetate test relative to that of multiplex PCR was 97.7% and 100% for protocol 1 and 2 respectively. This study showed that S. Paratyphi B dT+ is a common causative agent of gastroenteritis in Malaysia while paratyphoid fever appears to be relatively uncommon. Multiplex PCR was shown to be a simpler, more rapid and reliable method to discriminate S. Paratyphi B than the phenotypic lead acetate test.

stg fimbrial operon from S. Typhi STH2370 contributes to association and cell disruption of epithelial and macrophage-like cells.

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Berrocal, Liliana; Fuentes, Juan A; Trombert, A Nicole; Jofré, Matías R; Villagra, Nicolás A; Valenzuela, Luis M; Mora, Guido C

2015-07-07

Salmonella enterica serovar Typhi (S. Typhi) stg operon, encoding a chaperone/usher fimbria (CU), contributes to an increased adherence to human epithelial cells. However, one report suggests that the presence of the Stg fimbria impairs the monocyte--bacteria association, as deduced by the lower level of invasion to macrophage-like cells observed when the stg fimbrial cluster was overexpressed. Nevertheless, since other CU fimbrial structures increase the entry of S. Typhi into macrophages, and considering that transcriptomic analyses revealed that stg operon is indeed expressed in macrophages, we reassessed the role of the stg operon in the interaction between S. Typhi strain STH2370 and human cells, including macrophage-like cells and mononuclear cells directly taken from human peripheral blood. We compared S. Typhi STH2370 WT, a Chilean clinical strain, and the S. Typhi STH2370 Δstg mutant with respect to association and invasion using epithelial and macrophage-like cells. We observed that deletion of stg operon reduced the association and invasion of S. Typhi, in both cellular types. The presence of the cloned stg operon restored the WT phenotype in all the cases. Moreover, we compared Salmonella enterica sv. Typhimurium 14028s (S. Typhimurium, a serovar lacking stg operon) and S. Typhimurium heterologously expressing S. Typhi stg. We found that the latter presents an increased cell disruption of polarized epithelial cells and an increased association in both epithelial and macrophage-like cells. S. Typhi stg operon encodes a functional adhesin that participates in the interaction bacteria-eukaryotic cells, including epithelial cells and macrophages-like cells. The phenotypes associated to stg operon include increased association and consequent invasion in bacteria-eukaryotic cells, and cell disruption.

Nalidixic acid-resistant Salmonella enterica serotype Typhi presenting as a primary psoas abscess: case report and review of the literature.

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Shakespeare, William A; Davie, Daniel; Tonnerre, Claude; Rubin, Michael A; Strong, Michael; Petti, Cathy A

2005-02-01

We report an unusual case of Salmonella enterica serotype Typhi presenting as a primary psoas abscess. The isolate tested susceptible to ciprofloxacin but resistant to nalidixic acid in vitro, a pattern associated with fluoroquinolone therapeutic failures. We review the literature for serovar Typhi psoas abscess in the absence of bacteremia and discuss the importance of identifying isolates with reduced susceptibility to fluoroquinolones.

Antimicrobial susceptibility and serovars of Salmonella from chickens and humans in Ibadan, Nigeria

DEFF Research Database (Denmark)

Fashae, K; Ogunsola, F; Aarestrup, Frank Møller

2010-01-01

BACKGROUND: This study determines the prevalence and antibiotic resistance of Salmonella serovars from humans and chickens in Ibadan, Nigeria, in 2004-2007. METHODOLOGY: A total of 991 blood samples were collected from patients in 2004 to 2005 and 641 fecal samples were collected from poultry farms......% were (S. Typhi). The majority of serovars from humans were S. Enteritidis (33%), S. Dublin (18%), and S. Typhimurium (18%). Resistance to chloramphenicol, sulfamethoxazole, trimethoprim, and ampicillin ranged from 36% to 59% for the human isolates. Eight different serovars were obtained from chickens...

A strand-specific RNA-Seq analysis of the transcriptome of the typhoid bacillus Salmonella typhi.

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Timothy T Perkins

2009-07-01

Full Text Available High-density, strand-specific cDNA sequencing (ssRNA-seq was used to analyze the transcriptome of Salmonella enterica serovar Typhi (S. Typhi. By mapping sequence data to the entire S. Typhi genome, we analyzed the transcriptome in a strand-specific manner and further defined transcribed regions encoded within prophages, pseudogenes, previously un-annotated, and 3'- or 5'-untranslated regions (UTR. An additional 40 novel candidate non-coding RNAs were identified beyond those previously annotated. Proteomic analysis was combined with transcriptome data to confirm and refine the annotation of a number of hpothetical genes. ssRNA-seq was also combined with microarray and proteome analysis to further define the S. Typhi OmpR regulon and identify novel OmpR regulated transcripts. Thus, ssRNA-seq provides a novel and powerful approach to the characterization of the bacterial transcriptome.

Nalidixic Acid-Resistant Salmonella enterica Serotype Typhi Presenting as a Primary Psoas Abscess: Case Report and Review of the Literature

Science.gov (United States)

Shakespeare, William A.; Davie, Daniel; Tonnerre, Claude; Rubin, Michael A.; Strong, Michael; Petti, Cathy A.

2005-01-01

We report an unusual case of Salmonella enterica serotype Typhi presenting as a primary psoas abscess. The isolate tested susceptible to ciprofloxacin but resistant to nalidixic acid in vitro, a pattern associated with fluoroquinolone therapeutic failures. We review the literature for serovar Typhi psoas abscess in the absence of bacteremia and discuss the importance of identifying isolates with reduced susceptibility to fluoroquinolones. PMID:15695728

Genomic characterisation of invasive non-typhoidal Salmonella enterica Subspecies enterica Serovar Bovismorbificans isolates from Malawi.

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Christina Bronowski

2013-11-01

Full Text Available Invasive Non-typhoidal Salmonella (iNTS are an important cause of bacteraemia in children and HIV-infected adults in sub-Saharan Africa. Previous research has shown that iNTS strains exhibit a pattern of gene loss that resembles that of host adapted serovars such as Salmonella Typhi and Paratyphi A. Salmonella enterica serovar Bovismorbificans was a common serovar in Malawi between 1997 and 2004.We sequenced the genomes of 14 Malawian bacteraemia and four veterinary isolates from the UK, to identify genomic variations and signs of host adaptation in the Malawian strains.Whole genome phylogeny of invasive and veterinary S. Bovismorbificans isolates showed that the isolates are highly related, belonging to the most common international S. Bovismorbificans Sequence Type, ST142, in contrast to the findings for S. Typhimurium, where a distinct Sequence Type, ST313, is associated with invasive disease in sub-Saharan Africa. Although genome degradation through pseudogene formation was observed in ST142 isolates, there were no clear overlaps with the patterns of gene loss seen in iNTS ST313 isolates previously described from Malawi, and no clear distinction between S. Bovismorbificans isolates from Malawi and the UK. The only defining differences between S. Bovismorbificans bacteraemia and veterinary isolates were prophage-related regions and the carriage of a S. Bovismorbificans virulence plasmid (pVIRBov.iNTS S. Bovismorbificans isolates, unlike iNTS S. Typhiumrium isolates, are only distinguished from those circulating elsewhere by differences in the mobile genome. It is likely that these strains have entered a susceptible population and are able to take advantage of this niche. There are tentative signs of convergent evolution to a more human adapted iNTS variant. Considering its importance in causing disease in this region, S. Bovismorbificans may be at the beginning of this process, providing a reference against which to compare changes that may

Detection of Salmonella typhi by nested polymerase chain reaction in blood, urine, and stool samples

NARCIS (Netherlands)

Hatta, Mochammad; Smits, Henk L.

2007-01-01

A nested polymerase chain reaction (PCR) specific for Salmonella enterica serovar Typhi was used for the detection of the pathogen in blood, urine, and stool samples from 131 patients with clinical suspicion of typhoid fever. The sensitivity of blood culture, the PCRs with blood, urine, and feces,

Epidemiology, clinical presentation, and patterns of drug resistance of Salmonella Typhi in Karachi, Pakistan.

Science.gov (United States)

Khan, M Imran; Soofi, Sajid Bashir; Ochiai, R Leon; Khan, Mohammad Jawed; Sahito, Shah Muhammad; Habib, Mohammad Atif; Puri, Mahesh K; Von Seidlein, Lorenz; Park, Jin Kyung; You, Young Ae; Ali, Mohammad; Nizami, S Qamarudding; Acosta, Camilo J; Sack, R Bradley; Clemens, John D; Bhutta, Zulfiqar A

2012-10-19

Enteric fever remains a major public health problem in Asia. Planning appropriate preventive measures such as immunization requires a clear understanding of disease burden. We conducted a community-based surveillance for Salmonella Typhi infection in children in Karachi, Pakistan. A de jure household census was conducted at baseline in the study setting to enumerate all individuals. A health-care facility-based passive surveillance system was used to capture episodes of fever lasting three or more 3 days in children 2 to 16 years old. A total of 7,401 blood samples were collected for microbiological confirmation, out of which 189 S. Typhi and 32 S. Paratyphi A isolates were identified with estimated annual incidences of 451/100,000 (95% CI: 446 - 457) and 76/100,000 (95% CI: 74 - 78) respectively. At the time of presentation, after adjusting for age, there was an association between the duration of fever and temperature at presentation, and being infected with multidrug-resistant S. Typhi. Of 189 isolates 83 were found to be resistant to first-line antimicrobial therapy. There was no statistically significant difference in clinical presentation of blood culture sensitive and resistant S. Typhi isolates. Incidence of S. Typhi in children is high in urban squatter settlements of Karachi, Pakistan. Findings from this study identified duration of fever and temperature at the time of presentation as important symptoms associated with blood culture-confirmed typhoid fever. Preventive strategies such as immunization and improvements in water and sanitation conditions should be the focus of typhoid control in urban settlements of Pakistan.

Attenuated Salmonella enterica serovar Typhi and Shigella flexneri 2a strains mucosally deliver DNA vaccines encoding measles virus hemagglutinin, inducing specific immune responses and protection in cotton rats.

Science.gov (United States)

Pasetti, Marcela F; Barry, Eileen M; Losonsky, Genevieve; Singh, Mahender; Medina-Moreno, Sandra M; Polo, John M; Ulmer, Jeffrey; Robinson, Harriet; Sztein, Marcelo B; Levine, Myron M

2003-05-01

Measles remains a leading cause of child mortality in developing countries. Residual maternal measles antibodies and immunologic immaturity dampen immunogenicity of the current vaccine in young infants. Because cotton rat respiratory tract is susceptible to measles virus (MV) replication after intranasal (i.n.) challenge, this model can be used to assess the efficacy of MV vaccines. Pursuing a new measles vaccine strategy that might be effective in young infants, we used attenuated Salmonella enterica serovar Typhi CVD 908-htrA and Shigella flexneri 2a CVD 1208 vaccines to deliver mucosally to cotton rats eukaryotic expression plasmid pGA3-mH and Sindbis virus-based DNA replicon pMSIN-H encoding MV hemagglutinin (H). The initial i.n. dose-response with bacterial vectors alone identified a well-tolerated dosage (1 x 10(9) to 7 x 10(9) CFU) and a volume (20 micro l) that elicited strong antivector immune responses. Animals immunized i.n. on days 0, 28, and 76 with bacterial vectors carrying DNA plasmids encoding MV H or immunized parenterally with these naked DNA vaccine plasmids developed MV plaque reduction neutralizing antibodies and proliferative responses against MV antigens. In a subsequent experiment of identical design, cotton rats were challenged with wild-type MV 1 month after the third dose of vaccine or placebo. MV titers were significantly reduced in lung tissue of animals immunized with MV DNA vaccines delivered either via bacterial live vectors or parenterally. Since attenuated serovar Typhi and S. flexneri can deliver measles DNA vaccines mucosally in cotton rats, inducing measles immune responses (including neutralizing antibodies) and protection, boosting strategies can now be evaluated in animals primed with MV DNA vaccines.

Evolution of Salmonella enterica virulence via point mutations in the fimbrial adhesin.

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Dagmara I Kisiela

Full Text Available Whereas the majority of pathogenic Salmonella serovars are capable of infecting many different animal species, typically producing a self-limited gastroenteritis, serovars with narrow host-specificity exhibit increased virulence and their infections frequently result in fatal systemic diseases. In our study, a genetic and functional analysis of the mannose-specific type 1 fimbrial adhesin FimH from a variety of serovars of Salmonella enterica revealed that specific mutant variants of FimH are common in host-adapted (systemically invasive serovars. We have found that while the low-binding shear-dependent phenotype of the adhesin is preserved in broad host-range (usually systemically non-invasive Salmonella, the majority of host-adapted serovars express FimH variants with one of two alternative phenotypes: a significantly increased binding to mannose (as in S. Typhi, S. Paratyphi C, S. Dublin and some isolates of S. Choleraesuis, or complete loss of the mannose-binding activity (as in S. Paratyphi B, S. Choleraesuis and S. Gallinarum. The functional diversification of FimH in host-adapted Salmonella results from recently acquired structural mutations. Many of the mutations are of a convergent nature indicative of strong positive selection. The high-binding phenotype of FimH that leads to increased bacterial adhesiveness to and invasiveness of epithelial cells and macrophages usually precedes acquisition of the non-binding phenotype. Collectively these observations suggest that activation or inactivation of mannose-specific adhesive properties in different systemically invasive serovars of Salmonella reflects their dynamic trajectories of adaptation to a life style in specific hosts. In conclusion, our study demonstrates that point mutations are the target of positive selection and, in addition to horizontal gene transfer and genome degradation events, can contribute to the differential pathoadaptive evolution of Salmonella.

Prevalence of current patterns and predictive trends of multidrug-resistant Salmonella Typhi in Sudan.

Science.gov (United States)

Elshayeb, Ayman A; Ahmed, Abdelazim A; El Siddig, Marmar A; El Hussien, Adil A

2017-11-14

Enteric fever has persistence of great impact in Sudanese public health especially during rainy season when the causative agent Salmonella enterica serovar Typhi possesses pan endemic patterns in most regions of Sudan - Khartoum. The present study aims to assess the recent state of antibiotics susceptibility of Salmonella Typhi with special concern to multidrug resistance strains and predict the emergence of new resistant patterns and outbreaks. Salmonella Typhi strains were isolated and identified according to the guidelines of the International Standardization Organization and the World Health Organization. The antibiotics susceptibilities were tested using the recommendations of the Clinical Laboratories Standards Institute. Predictions of emerging resistant bacteria patterns and outbreaks in Sudan were done using logistic regression, forecasting linear equations and in silico simulations models. A total of 124 antibiotics resistant Salmonella Typhi strains categorized in 12 average groups were isolated, different patterns of resistance statistically calculated by (y = ax - b). Minimum bactericidal concentration's predication of resistance was given the exponential trend (y = n e x ) and the predictive coefficient R 2  > 0 current antimicrobial drug resistance patterns of community-acquired agents causing outbreaks.

A fast and highly sensitive blood culture PCR method for clinical detection of Salmonella enterica serovar Typhi

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Zhou Liqing

2010-04-01

Full Text Available Abstract Background Salmonella Typhi causes an estimated 21 million new cases of typhoid fever and 216,000 deaths every year. Blood culture is currently the gold standard for diagnosis of typhoid fever, but it is time-consuming and takes several days for isolation and identification of causative organisms. It is then too late to initiate proper antibiotic therapy. Serological tests have very low sensitivity and specificity, and no practical value in endemic areas. As early diagnosis of the disease and prompt treatment are essential for optimal management, especially in children, a rapid sensitive detection method for typhoid fever is urgently needed. Although PCR is sensitive and rapid, initial research indicated similar sensitivity to blood culture and lower specificity. We developed a fast and highly sensitive blood culture PCR method for detection of Salmonella Typhi, allowing same-day initiation of treatment after accurate diagnosis of typhoid. Methods An ox bile tryptone soy broth was optimized for blood culture, which allows the complete lysis of blood cells to release intracellular bacteria without inhibiting the growth of Salmonella Typhi. Using the optimised broth Salmonella Typhi bacteria in artificial blood samples were enriched in blood culture and then detected by a PCR targeting the fliC-d gene of Salmonella Typhi. Results Tests demonstrated that 2.4% ox bile in blood culture not only lyzes blood cells completely within 1.5 hours so that the intracellular bacteria could be released, but also has no inhibiting effect on the growth of Salmonella Typhi. Three hour enrichment of Salmonella Typhi in tryptone soya broth containing 2.4% ox bile could increase the bacterial number from 0.75 CFU per millilitre of blood which is similar to clinical typhoid samples to the level which regular PCR can detect. The whole blood culture PCR assay takes less than 8 hours to complete rather than several days for conventional blood culture

Diversity of Salmonella enterica serovar Typhi strains collected from india using variable number tandem repeat (VNTR)-PCR analysis.

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Sankar, Sathish; Kuppanan, Suresh; Nandagopal, Balaji; Sridharan, Gopalan

2013-08-01

Typhoid fever is endemic in India, and a seasonal increase of cases is observed annually. In spite of effective therapies and the availability of vaccines, morbidity is widespread owing to the circulation of multiple genetic variants, frequent migration of asymptomatic carriers, unhygienic food practices and the emergence of multidrug resistance and thus continues to be a major public health problem in developing countries, particularly in India. Classical methods of strain typing such as pulsed-field gel electrophoresis, ribotyping, random amplification of polymorphic DNA and amplified fragment length polymorphism are either laborious and technically complicated or less discriminatory. We investigated the molecular diversity of Indian strains of Salmonella enterica serovar Typhi (S. Typhi) isolated from humans from different parts of India to establish the molecular epidemiology of the organism using the variable number tandem repeat (VNTR)-PCR analysis. The electrophoretic band pattern was analysed using the GelCompar II software program. Of the 94 strains tested for three VNTRs loci, 75 VNTR genotypes were obtained. Of the three VNTRs tested in this study, VNTR1 was amplified in all the strains except one and found to be predominant. VNTR2 was amplified only in 57 strains with a Simpson diversity index of 0.93 indicating the high variability of this region within the strains. VNTR3 was amplified in 90 strains. The discriminatory power of this typing tool has been greatly enhanced by this VNTR2 region as the other two regions could not discriminate strains significantly. In our study, about 55 % of the strains amplified all three VNTR regions and 39 % of the strains lacked the VNTR2 region. Among the three VNTR regions tested, the majority of the strains produced similar banding pattern for any two regions grouped into a cluster. The strains grouped as a genotype were from the same geographical location. Strains collected from each geographical region were also

Molecular diagnosis of Salmonella typhi and its virulence in suspected typhoid blood samples through nested multiplex PCR.

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Prabagaran, Solai Ramatchandirane; Kalaiselvi, Vellingiri; Chandramouleeswaran, Naganathan; Deepthi, Krishnan Nair Geetha; Brahmadathan, Kootallur Narayanan; Mani, Mariappa

2017-08-01

A nested multiplex polymerase chain reaction (PCR) based diagnosis was developed for the detection of virulent Salmonella typhi in the blood specimens from patients suspected for typhoid fever. After the Widal test, two pairs of primers were used for the detection of flagellin gene (fliC) of S. typhi. Among them, those positive for fliC alone were subjected to identification of genes in Via B operon of Salmonella Pathogenesity Island (SPI-7) where four primer pairs were used to detect tviA and tviB genes. Among 250 blood samples tested, 115 were positive by fliC PCR; 22 of these were negative for tviA and tviB. Hence, the method described here can be used to diagnose the incidence of Vi-negative serovar typhi especially in endemic regions where the Vi vaccine is administered. Copyright © 2017 Elsevier B.V. All rights reserved.

Salmonella enterica serovar Ohio septic arthritis and bone abscess in an immunocompetent patient: a case report

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Kato Hideaki

2012-07-01

Full Text Available Abstract Introduction Non-typhi Salmonella species cause severe extra-intestinal focal infection after occult bacteremia. Although the number of cases of non-typhi salmonellosis is increasing worldwide among patients with immunocompromising conditions such as human immunodeficiency virus infection, infection is uncommon in immunocompetent subjects. We report a case of septic arthritis and bone abscess due to a rare non-typhi Salmonella organism that developed after a prolonged asymptomatic period. Case presentation A 44-year-old Japanese immunocompetent man presented with acute-onset left knee pain and swelling. He had no history of food poisoning, and his most recent travel to an endemic area was 19 years ago. Salmonella enterica serovar Ohio was identified from samples of bone abscess and joint tissue. Arthrotomy and necrotic tissue debridement followed by intravenous ceftriaxone was successful. Conclusions Non-typhi Salmonella species only rarely cause extra-intestinal focal infections in immunocompetent patients. Our case suggests that non-typhi Salmonella species can cause severe focal infections many years after the occult bacteremia associated with food poisoning.

Temporal fluctuation of multidrug resistant salmonella typhi haplotypes in the mekong river delta region of Vietnam.

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Kathryn E Holt

2011-01-01

Full Text Available typhoid fever remains a public health problem in Vietnam, with a significant burden in the Mekong River delta region. Typhoid fever is caused by the bacterial pathogen Salmonella enterica serovar Typhi (S. Typhi, which is frequently multidrug resistant with reduced susceptibility to fluoroquinolone-based drugs, the first choice for the treatment of typhoid fever. We used a GoldenGate (Illumina assay to type 1,500 single nucleotide polymorphisms (SNPs and analyse the genetic variation of S. Typhi isolated from 267 typhoid fever patients in the Mekong delta region participating in a randomized trial conducted between 2004 and 2005.the population of S. Typhi circulating during the study was highly clonal, with 91% of isolates belonging to a single clonal complex of the S. Typhi H58 haplogroup. The patterns of disease were consistent with the presence of an endemic haplotype H58-C and a localised outbreak of S. Typhi haplotype H58-E2 in 2004. H58-E2-associated typhoid fever cases exhibited evidence of significant geo-spatial clustering along the Sông H u branch of the Mekong River. Multidrug resistance was common in the established clone H58-C but not in the outbreak clone H58-E2, however all H58 S. Typhi were nalidixic acid resistant and carried a Ser83Phe amino acid substitution in the gyrA gene.the H58 haplogroup dominates S. Typhi populations in other endemic areas, but the population described here was more homogeneous than previously examined populations, and the dominant clonal complex (H58-C, -E1, -E2 observed in this study has not been detected outside Vietnam. IncHI1 plasmid-bearing S. Typhi H58-C was endemic during the study period whilst H58-E2, which rarely carried the plasmid, was only transient, suggesting a selective advantage for the plasmid. These data add insight into the outbreak dynamics and local molecular epidemiology of S. Typhi in southern Vietnam.

Structural and functional studies of a 50 kDa antigenic protein from Salmonella enterica serovar Typhi.

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Choong, Yee Siew; Lim, Theam Soon; Chew, Ai Lan; Aziah, Ismail; Ismail, Asma

2011-04-01

The high typhoid incidence rate in developing and under-developed countries emphasizes the need for a rapid, affordable and accessible diagnostic test for effective therapy and disease management. TYPHIDOT®, a rapid dot enzyme immunoassay test for typhoid, was developed from the discovery of a ∼50 kDa protein specific for Salmonella enterica serovar Typhi. However, the structure of this antigen remains unknown till today. Studies on the structure of this antigen are important to elucidate its function, which will in turn increase the efficiency of the development and improvement of the typhoid detection test. This paper described the predictive structure and function of the antigenically specific protein. The homology modeling approach was employed to construct the three-dimensional structure of the antigen. The built structure possesses the features of TolC-like outer membrane protein. Molecular docking simulation was also performed to further probe the functionality of the antigen. Docking results showed that hexamminecobalt, Co(NH(3))(6)(3+), as an inhibitor of TolC protein, formed favorable hydrogen bonds with D368 and D371 of the antigen. The single point (D368A, D371A) and double point (D368A and D371A) mutations of the antigen showed a decrease (single point mutation) and loss (double point mutations) of binding affinity towards hexamminecobalt. The architecture features of the built model and the docking simulation reinforced and supported that this antigen is indeed the variant of outer membrane protein, TolC. As channel proteins are important for the virulence and survival of bacteria, therefore this ∼50 kDa channel protein is a good specific target for typhoid detection test. Copyright © 2011 Elsevier Inc. All rights reserved.

An allele of an ancestral transcription factor dependent on a horizontally acquired gene product.

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Chen, H Deborah; Jewett, Mollie W; Groisman, Eduardo A

2012-01-01

Changes in gene regulatory circuits often give rise to phenotypic differences among closely related organisms. In bacteria, these changes can result from alterations in the ancestral genome and/or be brought about by genes acquired by horizontal transfer. Here, we identify an allele of the ancestral transcription factor PmrA that requires the horizontally acquired pmrD gene product to promote gene expression. We determined that a single amino acid difference between the PmrA proteins from the human adapted Salmonella enterica serovar Paratyphi B and the broad host range S. enterica serovar Typhimurium rendered transcription of PmrA-activated genes dependent on the PmrD protein in the former but not the latter serovar. Bacteria harboring the serovar Typhimurium allele exhibited polymyxin B resistance under PmrA- or under PmrA- and PmrD-inducing conditions. By contrast, isogenic strains with the serovar Paratyphi B allele displayed PmrA-regulated polymyxin B resistance only when experiencing activating conditions for both PmrA and PmrD. We establish that the two PmrA orthologs display quantitative differences in several biochemical properties. Strains harboring the serovar Paratyphi B allele showed enhanced biofilm formation, a property that might promote serovar Paratyphi B's chronic infection of the gallbladder. Our findings illustrate how subtle differences in ancestral genes can impact the ability of horizontally acquired genes to confer new properties.

Fatty Acid Profiling of Lipid A Isolated from Indigenous salmonella typhi strain by gas chromatography mass spectrometry

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Jabbar, A.; Ali, A.; Tawab, A.; Haque, A.; Iqbal, M. [National Inst. for Biotechnology and Genetic Engineering, Faisalabad (Pakistan)

2014-02-15

Typhoid, caused by Salmonella enterica serovar Typhi (S. Typhi), is a major health problem worldwide especially in developing countries. Lipopolysaccharides are one of the main virulence factors of S. Typhi. Hydrophobic lipid A anchors the lipopolysaccharides into the bacterial outer membrane and also serves as the epicenter of endotoxicity, which is linked to the presence of several fatty acid chains. Fatty acid profiling is, therefore, very important to understand the endotoxicity of these pathogenic bacteria. To profile lipid A with respect to its fatty acid constituents, a S. Typhi was isolated from blood culture of a typhoid patient from the Faisalabad region of Pakistan. After its complete identification using biochemical and molecular techniques, this bacterium was cultivated in a fermentor. The cell pellet obtained was subjected to hot phenol process to extract and purify lipopolysaccharides. Acid hydrolysis of the lipopolysaccharides yielded lipid A, which was subjected to analyses using GC-MS after derivatization into their fatty acid methyl esters. The fatty acid methyl esters were identified on the basis of their retention times, compared with standards as well as characteristic mass fragmentation patterns of their respective mass spectra. This fatty acid profiling revealed the occurrence of dodecanoic acid (C12:0), tetradecanoic acid (C14:0), 3-hydroxy tetradecanoic acid (3-OH C14:0) and hexadecanoic acid (C16:0) in the lipid A component of S. Typhi strain with the relative percentage abundances 8.5%, 12.5%, 55.9% and 23.1%, respectively. (author)

Fatty Acid Profiling of Lipid A Isolated from Indigenous salmonella typhi strain by gas chromatography mass spectrometry

International Nuclear Information System (INIS)

Jabbar, A.; Ali, A.; Tawab, A.; Haque, A.; Iqbal, M.

2014-01-01

Typhoid, caused by Salmonella enterica serovar Typhi (S. Typhi), is a major health problem worldwide especially in developing countries. Lipopolysaccharides are one of the main virulence factors of S. Typhi. Hydrophobic lipid A anchors the lipopolysaccharides into the bacterial outer membrane and also serves as the epicenter of endotoxicity, which is linked to the presence of several fatty acid chains. Fatty acid profiling is, therefore, very important to understand the endotoxicity of these pathogenic bacteria. To profile lipid A with respect to its fatty acid constituents, a S. Typhi was isolated from blood culture of a typhoid patient from the Faisalabad region of Pakistan. After its complete identification using biochemical and molecular techniques, this bacterium was cultivated in a fermentor. The cell pellet obtained was subjected to hot phenol process to extract and purify lipopolysaccharides. Acid hydrolysis of the lipopolysaccharides yielded lipid A, which was subjected to analyses using GC-MS after derivatization into their fatty acid methyl esters. The fatty acid methyl esters were identified on the basis of their retention times, compared with standards as well as characteristic mass fragmentation patterns of their respective mass spectra. This fatty acid profiling revealed the occurrence of dodecanoic acid (C12:0), tetradecanoic acid (C14:0), 3-hydroxy tetradecanoic acid (3-OH C14:0) and hexadecanoic acid (C16:0) in the lipid A component of S. Typhi strain with the relative percentage abundances 8.5%, 12.5%, 55.9% and 23.1%, respectively. (author)

Laboratory and molecular surveillance of paediatric typhoidal Salmonella in Nepal: Antimicrobial resistance and implications for vaccine policy.

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Carl D Britto

2018-04-01

Full Text Available Children are substantially affected by enteric fever in most settings with a high burden of the disease, including Nepal. However pathogen population structure and transmission dynamics are poorly delineated in young children, the proposed target group for immunization programs. Here we present whole genome sequencing and antimicrobial susceptibility data on 198 S. Typhi and 66 S. Paratyphi A isolated from children aged 2 months to 15 years of age during blood culture surveillance at Patan Hospital, Nepal, 2008-2016.S. Typhi was the dominant agent and comprised several distinct genotypes, dominated by 4.3.1 (H58. The heterogeneity of genotypes in children under five was reduced compared to data from 2005-2006, attributable to ongoing clonal expansion of H58. Most isolates (86% were non-susceptible to fluoroquinolones, associated mainly with S. Typhi H58 lineage II and S. Paratyphi A harbouring mutations in the quinolone resistance-determining region (QRDR; non-susceptible strains from these groups accounted for 50% and 25% of all isolates. Multi-drug resistance (MDR was rare (3.5% of S. Typhi, 0 S. Paratyphi A and restricted to chromosomal insertions of resistance genes in H58 lineage I strains. Temporal analyses revealed a shift in dominance from H58 Lineage I to H58 Lineage II, with the latter being significantly more common after 2010. Comparison to global data sets showed the local S. Typhi and S. Paratyphi A strains had close genetic relatives in other South Asian countries, indicating regional strain circulation. Multiple imports from India of ciprofloxacin-resistant H58 lineage II strains were identified, but these were rare and showed no evidence of clonal replacement of local S. Typhi.These data indicate that enteric fever in Nepal continues to be a major public health issue with ongoing inter- and intra-country transmission, and highlights the need for regional coordination of intervention strategies. The absence of a S. Paratyphi A

Sensitivitas Salmonella Sp. Penyebab Demam Tifoid Terhadap Beberapa Antibiotik di Rumah Sakit Immanuel Bandung

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Yanti Mulyana

2009-09-01

Full Text Available Typhoid fever is an enteric fever caused by Salmonella sp. especially Salmonella typhi and Salmonella paratyphi. Various antibiotics used for therapy beside chloramphenicol as drug of choice. Non rational use of antibiotics may result increasing of resistence in bacteria. The aim of the research is to know the sensitivity of Salmonella typhi and Salmonella paratyphi to some antibiotics. The purpose is to gather information about antibiotics which are still effective for typhoid fever and enteric therapy. Salmonella typhi and Salmonella paratyphi strain from positive cultures diagnose typhoid fever patients at Immanuel Hospital Bandung during 2004-2007. The method of resistance is Kirby Bauer's disk diffusion assay with NCCLS standard. The disk antibiotics used are amoxicillin, amoxicillinclavulanic acid, chloramphenicol, ciprofloxacin, ceftriaxone, trimethoprim, and trimethoprim-sulfamethoxazole. The result showed penicillin group, amoxicillin and amoxicillin-clavulanic acid had 96.3–99.68% sensitive against Salmonella sp. Sensitivity of chloramphenicol as drug of choice of typhoid fever still 99.05%. Since the sensitivity less than 100%, it means there was about 8% resistence. Thats why eventhough this data can be used as empiric therapy, the writer suggest to do sensitivity test to Salmonella sp. that caused typhoid to get rationally dan effective treatment. From the result, it's concluded that Salmonella typhi and Salmonella paratyphi are still sensitive to all that antibiotics.

Prevalence of current patterns and predictive trends of multidrug-resistant Salmonella Typhi in Sudan

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Ayman A. Elshayeb

2017-11-01

Full Text Available Abstract Background Enteric fever has persistence of great impact in Sudanese public health especially during rainy season when the causative agent Salmonella enterica serovar Typhi possesses pan endemic patterns in most regions of Sudan - Khartoum. Objectives The present study aims to assess the recent state of antibiotics susceptibility of Salmonella Typhi with special concern to multidrug resistance strains and predict the emergence of new resistant patterns and outbreaks. Methods Salmonella Typhi strains were isolated and identified according to the guidelines of the International Standardization Organization and the World Health Organization. The antibiotics susceptibilities were tested using the recommendations of the Clinical Laboratories Standards Institute. Predictions of emerging resistant bacteria patterns and outbreaks in Sudan were done using logistic regression, forecasting linear equations and in silico simulations models. Results A total of 124 antibiotics resistant Salmonella Typhi strains categorized in 12 average groups were isolated, different patterns of resistance statistically calculated by (y = ax − b. Minimum bactericidal concentration’s predication of resistance was given the exponential trend (y = n ex and the predictive coefficient R2 > 0 < 1 are approximately alike. It was assumed that resistant bacteria occurred with a constant rate of antibiotic doses during the whole experimental period. Thus, the number of sensitive bacteria decreases at the same rate as resistant occur following term to the modified predictive model which solved computationally. Conclusion This study assesses the prediction of multi-drug resistance among S. Typhi isolates by applying low cost materials and simple statistical methods suitable for the most frequently used antibiotics as typhoid empirical therapy. Therefore, bacterial surveillance systems should be implemented to present data on the aetiology and current

In vitro Antibacterial Activity of Alchornea cordifolia Bark Extract ...

African Journals Online (AJOL)

Four extracts of Alchornea cordifolia (Schumach.) Müll. Arg. (Euphorbiaceae) bark, including aqueous, methanol, acetone and hexane extracts, were tested for their antibacterial activities against Salmonella typhi, Salmonella paratyphi A and Salmonella paratyphi B, using both agar diffusion and broth dilution methods.

Understanding paratyphoid infection: study protocol for the development of a human model of Salmonella enterica serovar Paratyphi A challenge in healthy adult volunteers.

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McCullagh, David; Dobinson, Hazel C; Darton, Thomas; Campbell, Danielle; Jones, Claire; Snape, Matthew; Stevens, Zoe; Plested, Emma; Voysey, Merryn; Kerridge, Simon; Martin, Laura B; Angus, Brian; Pollard, Andrew J

2015-06-16

This study will develop the first human challenge model of paratyphoid infection which may then be taken forward to evaluate paratyphoid vaccine candidates. Salmonella Paratyphi A is believed to cause a quarter of the estimated 20 million cases of enteric fever annually. Epidemiological evidence also suggests that an increasing proportion of the enteric fever burden is attributable to S. Paratyphi infection meriting further attention and interest in vaccine development. Assessment of paratyphoid vaccine efficacy in preclinical studies is complicated by the lack of a small animal model and the human-restricted nature of the infection. The use of experimental human infection in healthy volunteers provides an opportunity to address these problems in a cost-effective manner. Volunteers will ingest virulent S. Paratyphi A bacteria (NVGH308 strain) with a bicarbonate buffer solution to establish the infectious dose resulting in an 'attack rate' of 60-75%. Using an a priori decision-making algorithm, the challenge dose will be escalated or de-escalated to achieve the target attack rate, with the aim of reaching the study end point while exposing as few individuals as possible to infection. The attack rate will be determined by the proportion of paratyphoid infection in groups of 20 healthy adult volunteers, with infection being defined by one or more positive blood cultures (microbiological end point) and/or fever, defined as an oral temperature exceeding 38 °C sustained for at least 12 h (clinical end point); 20-80 participants will be required. Challenge participants will start a 2-week course of an oral antibiotic on diagnosis of infection, or after 14 days follow-up. The strict eligibility criterion aims to minimise risk to participants and their close contacts. Ethical approval has been obtained. The results will be disseminated in a peer-reviewed journal and presented at international congresses. NCT02100397. Published by the BMJ Publishing Group Limited. For

Molecular and Clinical Epidemiology of Salmonella Paratyphi A Isolated from Patients with Bacteremia in Nepal.

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Sherchan, Jatan Bahadur; Morita, Masatomo; Matono, Takashi; Izumiya, Hidemasa; Ohnishi, Makoto; Sherchand, Jeevan B; Tandukar, Sarmila; Laghu, Ujjwal; Nagamatsu, Maki; Kato, Yasuyuki; Ohmagari, Norio; Hayakawa, Kayoko

2017-12-01

Little is known about the epidemiology of typhoid and paratyphoid fever in Nepal. We aimed to elucidate the molecular and clinical epidemiology of Salmonella Paratyphi A in Nepal. Isolates were collected from 23 cases of bacteremia due to S. Paratyphi A between December 2014 and October 2015. Thirteen patients (57%) were male, and the median age was 21 years. None of the patients had an underlying chronic disease. All S. Paratyphi A isolates were sensitive to ampicillin, trimethoprim/sulfamethoxazole, ceftriaxone, and chloramphenicol. All isolates were resistant to nalidixic acid and were categorized as intermediately susceptible to levofloxacin. Phylogenetic analysis revealed close relatedness among the isolates, including several clonal groups, suggesting local spread. Patients with bacteremia due to S. Paratyphi A in Kathmandu, Nepal, were relatively young and nondebilitated. Improving control of S . Paratyphi infections should focus on effective infection control measures and selection of empirical therapy based on current resistance patterns.

Polyamines are essential for virulence in Salmonella enterica serovar Gallinarum despite evolutionary decay of polyamine biosynthesis genes.

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Schroll, Casper; Christensen, Jens P; Christensen, Henrik; Pors, Susanne E; Thorndahl, Lotte; Jensen, Peter R; Olsen, John E; Jelsbak, Lotte

2014-05-14

Serovars of Salmonella enterica exhibit different host-specificities where some have broad host-ranges and others, like S. Gallinarum and S. Typhi, are host-specific for poultry and humans, respectively. With the recent availability of whole genome sequences it has been reported that host-specificity coincides with accumulation of pseudogenes, indicating adaptation of host-restricted serovars to their narrow niches. Polyamines are small cationic amines and in Salmonella they can be synthesized through two alternative pathways directly from l-ornithine to putrescine and from l-arginine via agmatine to putrescine. The first pathway is not active in S. Gallinarum and S. Typhi, and this prompted us to investigate the importance of polyamines for virulence in S. Gallinarum. Bioinformatic analysis of all sequenced genomes of Salmonella revealed that pseudogene formation of the speC gene was exclusive for S. Typhi and S. Gallinarum and happened through independent events. The remaining polyamine biosynthesis pathway was found to be essential for oral infection with S. Gallinarum since single and double mutants in speB and speE, encoding the pathways from agmatine to putrescine and from putrescine to spermidine, were attenuated. In contrast, speB was dispensable after intraperitoneal challenge, suggesting that putrescine was less important for the systemic phase of the disease. In support of this hypothesis, a ΔspeE;ΔpotCD mutant, unable to synthesize and import spermidine, but with retained ability to import and synthesize putrescine, was attenuated after intraperitoneal infection. We therefore conclude that polyamines are essential for virulence of S. Gallinarum. Furthermore, our results point to distinct roles for putrescine and spermidine during systemic infection. Copyright © 2014 Elsevier B.V. All rights reserved.

Microcontact Imprinted Plasmonic Nanosensors: Powerful Tools in the Detection of Salmonella paratyphi

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Işık Perçin

2017-06-01

Full Text Available Identification of pathogenic microorganisms by traditional methods is slow and cumbersome. Therefore, the focus today is on developing new and quicker analytical methods. In this study, a Surface Plasmon Resonance (SPR sensor with a microcontact imprinted sensor chip was developed for detecting Salmonella paratyphi. For this purpose, the stamps of the target microorganism were prepared and then, microcontact S. paratyphi-imprinted SPR chips were prepared with the functional monomer N-methacryloyl-L-histidine methyl ester (MAH. Characterization studies of the SPR chips were carried out with ellipsometry and scanning electron microscopy (SEM. The real-time Salmonella paratyphi detection was performed within the range of 2.5 × 106–15 × 106 CFU/mL. Selectivity of the prepared sensors was examined by using competing bacterial strains such as Escherichia coli, Staphylococcus aureus and Bacillus subtilis. The imprinting efficiency of the prepared sensor system was determined by evaluating the responses of the SPR chips prepared with both molecularly imprinted polymers (MIPs and non-imprinted polymers (NIPs. Real sample experiments were performed with apple juice. The recognition of Salmonella paratyphi was achieved using these SPR sensor with a detection limit of 1.4 × 106 CFU/mL. In conclusion, SPR sensor has the potential to serve as an excellent candidate for monitoring Salmonella paratyphi in food supplies or contaminated water and clearly makes it possible to develop rapid and appropriate control strategies.

Inhibitory Effects of Several Essential Oils towards Salmonella typhimurium, Salmonella paratyphi A and Salmonella paratyphi B

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S.F. Mazhar

2014-09-01

Full Text Available Plant essential oils are natural products extracted from plants and because of their antimicrobial properties can be used as natural additives in foods. They are also useful for decontamination of food-borne pathogens and can be a safe additive in foods. The antimicrobial activities of essential oils belonging to Saturiea hortensis, Thymus vulgaris, Mentha polegium, Cuminum cyminum, Lavandula officinalis and Mentha viridis L. (spearmint were investigated at different concentrations (0.1, 0.3, 0.5, 1, 2, 5 and 10%v/v against Salmonella typhimurium, Salmonella paratyphi A and Salmonella paratyphi B by using the agar well diffusion method. Essential oils showed inhibitory effect on Salmonella spp. in the agar well diffusion assay. In addition, the capability of essential oils for decontamination of minced row beef, ground beef, minced raw chicken and minced raw fish inoculated with Salmonella spp. at 0.1 and 0.5%v/v were assessed. Reduction of the Salmonella spp. population was observed following the inoculation of the cultures with 0.1 and 0.5%v/v essential oils.

Salmonella Pathogenicity and Host Adaptation in Chicken-Associated Serovars

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Johnson, Timothy J.; Ricke, Steven C.; Nayak, Rajesh; Danzeisen, Jessica

2013-01-01

SUMMARY Enteric pathogens such as Salmonella enterica cause significant morbidity and mortality. S. enterica serovars are a diverse group of pathogens that have evolved to survive in a wide range of environments and across multiple hosts. S. enterica serovars such as S. Typhi, S. Dublin, and S. Gallinarum have a restricted host range, in which they are typically associated with one or a few host species, while S. Enteritidis and S. Typhimurium have broad host ranges. This review examines how S. enterica has evolved through adaptation to different host environments, especially as related to the chicken host, and continues to be an important human pathogen. Several factors impact host range, and these include the acquisition of genes via horizontal gene transfer with plasmids, transposons, and phages, which can potentially expand host range, and the loss of genes or their function, which would reduce the range of hosts that the organism can infect. S. Gallinarum, with a limited host range, has a large number of pseudogenes in its genome compared to broader-host-range serovars. S. enterica serovars such as S. Kentucky and S. Heidelberg also often have plasmids that may help them colonize poultry more efficiently. The ability to colonize different hosts also involves interactions with the host's immune system and commensal organisms that are present. Thus, the factors that impact the ability of Salmonella to colonize a particular host species, such as chickens, are complex and multifactorial, involving the host, the pathogen, and extrinsic pressures. It is the interplay of these factors which leads to the differences in host ranges that we observe today. PMID:24296573

115 THE SENSITIVITY OF DIAZO TEST IN THE DIAGNOSIS OF ...

African Journals Online (AJOL)

Salmonella typhi was the predominant serotype causing typhoid/paratyphoid fevers, followed by S. paratypi A; S. paratyphi C and S. paratyphi B respectively. Although. Diazo test does not appear to be reliable, it could still be useful alongside with Widal agglutination test in endemic rural or urban areas where electricity and ...

Baseline Antibody Titre against Salmonella enterica in Healthy Population of Mumbai, Maharashtra, India.

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Patki, Rucha; Lilani, Sunil; Lanjewar, Dhaneshwar

2017-01-01

The aim of this study was to establish a baseline titre for the population of Mumbai, Maharashtra, India. Four hundred healthy blood donors, attending blood donation camps, were screened using a survey questionnaire. Widal tube agglutination test was performed on the diluted sera (with 0.9% normal saline) of blood donors, with final dilution ranging from 1 : 40 to 1 : 320. Out of 400 individuals providing samples, 78 (19.5%) individuals showed antibody titres ≥ 1 : 40 for at least one antigen and 322 (80.5%) showed no agglutination. The baseline antibody titres against O antigen and H antigen of Salmonella enterica serotype Typhi were found to be 1 : 40 and 1 : 80, respectively. Similarly, the baseline antibody titres for the H antigen of Salmonella enterica serotypes Paratyphi A and Paratyphi B were found to be 1 : 40 and 1 : 80, respectively. Thus, it was noted that the diagnostically significant cutoff of antibody titre from acute phase sample was ≥ 1 : 80 for S. Typhi O antigen and titre of ≥ 1 : 160 for both S. Typhi H antigen and S. Paratyphi BH antigen. Antibody titre of ≥ 1 : 80 can be considered significant for S. Paratyphi AH antigen.

Baseline Antibody Titre against Salmonella enterica in Healthy Population of Mumbai, Maharashtra, India

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Rucha Patki

2017-01-01

Full Text Available Objective. The aim of this study was to establish a baseline titre for the population of Mumbai, Maharashtra, India. Method. Four hundred healthy blood donors, attending blood donation camps, were screened using a survey questionnaire. Widal tube agglutination test was performed on the diluted sera (with 0.9% normal saline of blood donors, with final dilution ranging from 1 : 40 to 1 : 320. Results. Out of 400 individuals providing samples, 78 (19.5% individuals showed antibody titres ≥ 1 : 40 for at least one antigen and 322 (80.5% showed no agglutination. The baseline antibody titres against O antigen and H antigen of Salmonella enterica serotype Typhi were found to be 1 : 40 and 1 : 80, respectively. Similarly, the baseline antibody titres for the H antigen of Salmonella enterica serotypes Paratyphi A and Paratyphi B were found to be 1 : 40 and 1 : 80, respectively. Conclusion. Thus, it was noted that the diagnostically significant cutoff of antibody titre from acute phase sample was ≥ 1 : 80 for S. Typhi O antigen and titre of ≥ 1 : 160 for both S. Typhi H antigen and S. Paratyphi BH antigen. Antibody titre of ≥ 1 : 80 can be considered significant for S. Paratyphi AH antigen.

Global MLST of Salmonella Typhi Revisited in Post-Genomic Era: Genetic conservation, Population Structure and Comparative genomics of rare sequence types

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Kien-Pong eYap

2016-03-01

Full Text Available Typhoid fever, caused by Salmonella enterica serovar Typhi, remains an important public health burden in Southeast Asia and other endemic countries. Various genotyping methods have been applied to study the genetic variations of this human-restricted pathogen. Multilocus Sequence Typing (MLST is one of the widely accepted methods, and recently, there is a growing interest in the re-application of MLST in the post-genomic era. In this study, we provide the global MLST distribution of S. Typhi utilizing both publicly available 1,826 S. Typhi genome sequences in addition to performing conventional MLST on S. Typhi strains isolated from various endemic regions spanning over a century. Our global MLST analysis confirms the predominance of two sequence types (ST1 and ST2 co-existing in the endemic regions. Interestingly, S. Typhi strains with ST8 are currently confined within the African continent. Comparative genomic analyses of ST8 and other rare STs with genomes of ST1/ST2 revealed unique mutations in important virulence genes such as flhB, sipC and tviD that may explain the variations that differentiate between seemingly successful (widespread and unsuccessful (poor dissemination S. Typhi populations. Large scale whole-genome phylogeny demonstrated evidence of phylogeographical structuring and showed that ST8 may have diverged from the earlier ancestral population of ST1 and ST2, which later lost some of its fitness advantages, leading to poor worldwide dissemination. In response to the unprecedented increase in genomic data, this study demonstrates and highlights the utility of large-scale genome-based MLST as a quick and effective approach to narrow the scope of in-depth comparative genomic analysis and consequently provide new insights into the fine scale of pathogen evolution and population structure.

Multilocus sequence typing as a replacement for serotyping in Salmonella enterica.

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Mark Achtman

Full Text Available Salmonella enterica subspecies enterica is traditionally subdivided into serovars by serological and nutritional characteristics. We used Multilocus Sequence Typing (MLST to assign 4,257 isolates from 554 serovars to 1092 sequence types (STs. The majority of the isolates and many STs were grouped into 138 genetically closely related clusters called eBurstGroups (eBGs. Many eBGs correspond to a serovar, for example most Typhimurium are in eBG1 and most Enteritidis are in eBG4, but many eBGs contained more than one serovar. Furthermore, most serovars were polyphyletic and are distributed across multiple unrelated eBGs. Thus, serovar designations confounded genetically unrelated isolates and failed to recognize natural evolutionary groupings. An inability of serotyping to correctly group isolates was most apparent for Paratyphi B and its variant Java. Most Paratyphi B were included within a sub-cluster of STs belonging to eBG5, which also encompasses a separate sub-cluster of Java STs. However, diphasic Java variants were also found in two other eBGs and monophasic Java variants were in four other eBGs or STs, one of which is in subspecies salamae and a second of which includes isolates assigned to Enteritidis, Dublin and monophasic Paratyphi B. Similarly, Choleraesuis was found in eBG6 and is closely related to Paratyphi C, which is in eBG20. However, Choleraesuis var. Decatur consists of isolates from seven other, unrelated eBGs or STs. The serological assignment of these Decatur isolates to Choleraesuis likely reflects lateral gene transfer of flagellar genes between unrelated bacteria plus purifying selection. By confounding multiple evolutionary groups, serotyping can be misleading about the disease potential of S. enterica. Unlike serotyping, MLST recognizes evolutionary groupings and we recommend that Salmonella classification by serotyping should be replaced by MLST or its equivalents.

Infarction of spleen in typhoid fever

International Nuclear Information System (INIS)

Mehta, Lalit K.; Arya, Subhash C.; Mathai, G.

2007-01-01

Ultrasonography and computed tomography scan with hypo echoic areas diagnosed a splenic infarction in a Salmonella typhi infected 30-year-old man with painful hypochondrium and epigastrium. An antibiotic recipe of ceftriaxone and amikacin resulted in recovery. Imaging techniques contribute remarkably to a rapid diagnosis and rational management of the extra intestinal lesions attributable to the Salmonella typhi/paratyphi group of organisms. (author)

Infarction of spleen in typhoid fever

Energy Technology Data Exchange (ETDEWEB)

Mehta, Lalit K; Arya, Subhash C; Mathai, G [Dept. of Internal Medicine, Clinical Microbiology and Infection Control, Sant Parmanand Hospital, Delhi (India)

2007-07-01

Ultrasonography and computed tomography scan with hypo echoic areas diagnosed a splenic infarction in a Salmonella typhi infected 30-year-old man with painful hypochondrium and epigastrium. An antibiotic recipe of ceftriaxone and amikacin resulted in recovery. Imaging techniques contribute remarkably to a rapid diagnosis and rational management of the extra intestinal lesions attributable to the Salmonella typhi/paratyphi group of organisms. (author)

Isolation and characterization of polyvalent bacteriophages infecting multi drug resistant Salmonella serovars isolated from broilers in Egypt.

Science.gov (United States)

Mahmoud, Mayada; Askora, Ahmed; Barakat, Ahmed Barakat; Rabie, Omar El-Farouk; Hassan, Sayed Emam

2018-02-02

In this study, we isolated and characterized three phages named as Salmacey1, Salmacey2 and Salmacey3, infecting multi drug resistant Salmonella serovars isolated from broilers in Egypt. The most prevalent Salmonella serovars were S. typhimurium, S. enteritidis, and S. kentucky. All these Salmonella serovars were found to be resistant to more than two of the ten antimicrobial agents tested. Only S. kentucky was found to be resistant to seven antimicrobial agents. Examination of these phage particles by transmission electron microscopy (TEM), demonstrated that two phages (Salmacey1, Salmacey2) were found to belong to family Siphoviridae, and Salmacey3 was assigned to the family Myoviridae. The results of host range assay revealed that these bacteriophages were polyvalent and thus capable of infecting four strains of Salmonella serovars and Citrobacter freundii. Moreover, the two phages (Salmacey1, Salmacey2) had a lytic effect on Enterobacter cloacae and Salmacey3 was able to infect E. coli. All phages could not infect S. para Typhi, Staphylococus aureus and Bacillus cereus. One-step growth curves of bacteriophages revealed that siphovirus phages (Salmacey1, Salmacey2) have burst size (80 and 90pfu per infected cell with latent period 35min and 40min respectively), and for the myovirus Salmacey3 had a burst size 110pfu per infected cell with latent period 60min. Molecular analyses indicated that these phages contained double-stranded DNA genomes. The lytic activity of the phages against the most multidrug resistant serovars S. kentucky as host strain was evaluated. The result showed that these bacteriophages were able to completely stop the growth of S. kentucky in vitro. These results suggest that phages have a high potential for phage application to control Salmonella serovars isolated from broilers in Egypt. Copyright © 2017. Published by Elsevier B.V.

Breast abscess due to Salmonella paratyphi A : Case reports with review of literature.

Science.gov (United States)

Agrawal, Sonu; Yadav, Vishwanath Singh; Srivastava, Anurag; Kapil, Arti; Dhawan, Benu

2018-05-01

Salmonella paratyphi A causes paratyphoid fever which is characterized by acute onset of fever, abdominal pain, diarrhoea, nausea and vomiting. Localized disease can occur following both overt and silent bacteremia followed by seeding of bacteria at distant sites. Salmonella species though associated with abscess formation in various organs,are rarely associated with breast abscess. We report 2 cases of breast abscess due to Salmonella enterica serotype paratyphi A. Appropriate sampling, surgery supplemented by a comprehensive microbiological work up aided in pathogen identification and appropriate antibiotic administration for a successful outcome of these patients.

Current antimicrobial sensitivity pattern of typhoidal salmonellae in a referral diagnostic centre

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Umer Shujat

2016-03-01

Full Text Available Background: Infections caused by typhoidal salmonellae are an important public health concern in Pakistan. Inappropriate and injudicious use of fluoroquinolones has reduced their efficacy due to development of high level resistance. Aim: To ascertain the current susceptibility pattern of typhoidal salmonellae thus guiding the physicians for better management of typhoid patients.Materials and Methods: A study was conducted at our institution from January 2012 through December 2013 to investigate current susceptibility pattern of typhoidal salmonellae. Results: Out of 200 isolates, 107 (53.5% were identified as Salmonella Typhi and 93 (46.5% as Salmonella Paratyphi A. Sensitivities of Salmonella Typhi were as follows: ampicillin (48.6%, chloramphenicol (45.8%, co-trimoxazole (40.1%, ciprofloxacin (11.2%. Sensitivities of Salmonella Paratyphi A were: ampicillin (80.6%, chloramphenicol (89.2%, co-trimoxazole (90.3%, and ciprofloxacin (16.1%. No resistance was detected against third generation cephalosporins. Conclusions: Typhoidal salmonellae are still entirely susceptible to third generation cephalosporins in our setting. Marked rise in resistance to fluoroquinolones has reduced their empirical usage. Sensitivity of Salmonella Paratyphi A to conventional antityphoid drugs was encouraging.

Activation of Salmonella Typhi-specific regulatory T cells in typhoid disease in a wild-type S. Typhi challenge model.

OpenAIRE

Monica A McArthur; Stephanie Fresnay; Laurence S Magder; Thomas C Darton; Claire Jones; Claire S Waddington; Christoph J Blohmke; Gordon Dougan; Brian Angus; Myron M Levine; Andrew J Pollard; Marcelo B Sztein

2015-01-01

Salmonella Typhi (S. Typhi), the causative agent of typhoid fever, causes significant morbidity and mortality worldwide. Currently available vaccines are moderately efficacious, and identification of immunological responses associated with protection or disease will facilitate the development of improved vaccines. We investigated S. Typhi-specific modulation of activation and homing potential of circulating regulatory T cells (Treg) by flow and mass cytometry using specimens obtained from a h...

Identification of immunogenic Salmonella enterica serotype Typhi antigens expressed in chronic biliary carriers of S. Typhi in Kathmandu, Nepal.

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Richelle C Charles

Full Text Available Salmonella enterica serotype Typhi can colonize and persist in the biliary tract of infected individuals, resulting in a state of asymptomatic chronic carriage. Chronic carriers may act as persistent reservoirs of infection within a community and may introduce infection to susceptible individuals and new communities. Little is known about the interaction between the host and pathogen in the biliary tract of chronic carriers, and there is currently no reliable diagnostic assay to identify asymptomatic S. Typhi carriage.To study host-pathogen interactions in the biliary tract during S. Typhi carriage, we applied an immunoscreening technique called in vivo-induced antigen technology (IVIAT, to identify potential biomarkers unique to carriers. IVIAT identifies humorally immunogenic bacterial antigens expressed uniquely in the in vivo environment, and we hypothesized that S. Typhi surviving in the biliary tract of humans may express a distinct antigenic profile. Thirteen S. Typhi antigens that were immunoreactive in carriers, but not in healthy individuals from a typhoid endemic area, were identified. The identified antigens included a number of putative membrane proteins, lipoproteins, and hemolysin-related proteins. YncE (STY1479, an uncharacterized protein with an ATP-binding motif, gave prominent responses in our screen. The response to YncE in patients whose biliary tract contained S. Typhi was compared to responses in patients whose biliary tract did not contain S. Typhi, patients with acute typhoid fever, and healthy controls residing in a typhoid endemic area. Seven of 10 (70% chronic carriers, 0 of 8 bile culture-negative controls (0%, 0 of 8 healthy Bangladeshis (0%, and 1 of 8 (12.5% Bangladeshis with acute typhoid fever had detectable anti-YncE IgG in blood. IgA responses were also present.Further evaluation of YncE and other antigens identified by IVIAT could lead to the development of improved diagnostic assays to identify asymptomatic

Selection of Potential Therapeutic Bacteriophages that Lyse a CTX-M-15 Extended Spectrum β-Lactamase Producing Salmonella enterica Serovar Typhi Strain from the Democratic Republic of the Congo

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Elene Kakabadze

2018-04-01

Full Text Available Recently, a Salmonella Typhi isolate producing CTX-M-15 extended spectrum β-lactamase (ESBL and with decreased ciprofloxacin susceptibility was isolated in the Democratic Republic of the Congo. We have selected bacteriophages that show strong lytic activity against this isolate and have potential for phage-based treatment of S. Typhi, and Salmonella in general.

Anaerobiosis induced virulence of Salmonella typhi

DEFF Research Database (Denmark)

Kapoor, Sarika; Singh, R D; Sharma, P C

2002-01-01

, we examined the effect of anaerobiosis on the virulence of Salmonella Typhi, a Gram negative bacteria which invades through the gut mucosa and is responsible for typhoid fever. METHODS: Salmonella Typhi (ty2) was cultured in aerobic and anaerobic conditions to compare its virulence by rabbit ileal...

Crl binds to domain 2 of σ(S) and confers a competitive advantage on a natural rpoS mutant of Salmonella enterica serovar Typhi.

Science.gov (United States)

Monteil, Véronique; Kolb, Annie; Mayer, Claudine; Hoos, Sylviane; England, Patrick; Norel, Françoise

2010-12-01

The RpoS sigma factor (σ(S)) is the master regulator of the bacterial response to a variety of stresses. Mutants in rpoS arise in bacterial populations in the absence of stress, probably as a consequence of a subtle balance between self-preservation and nutritional competence. We characterized here one natural rpoS mutant of Salmonella enterica serovar Typhi (Ty19). We show that the rpoS allele of Ty19 (rpoS(Ty19)) led to the synthesis of a σ(S)(Ty19) protein carrying a single glycine-to-valine substitution at position 282 in σ(S) domain 4, which was much more dependent than the wild-type σ(S) protein on activation by Crl, a chaperone-like protein that increases the affinity of σ(S) for the RNA polymerase core enzyme (E). We used the bacterial adenylate cyclase two-hybrid system to demonstrate that Crl bound to residues 72 to 167 of σ(S) domain 2 and that G282V substitution did not directly affect Crl binding. However, this substitution drastically reduced the ability of σ(S)(Ty19) to bind E in a surface plasmon resonance assay, a defect partially rescued by Crl. The modeled structure of the Eσ(S) holoenzyme suggested that substitution G282V could directly disrupt a favorable interaction between σ(S) and E. The rpoS(Ty19) allele conferred a competitive fitness when the bacterial population was wild type for crl but was outcompeted in Δcrl populations. Thus, these results indicate that the competitive advantage of the rpoS(Ty19) mutant is dependent on Crl and suggest that crl plays a role in the appearance of rpoS mutants in bacterial populations.

Antibacterial activity of methylglyoxal against multi-drug resistant Salmonella Typhi

International Nuclear Information System (INIS)

Afzal, R.K.; Ahmed, A.

2018-01-01

To evaluate the antibacterial activity of MGO against MDR Salmonella typhi isolated from blood culture specimens and compare this activity against non-MDR S. typhi and with other gram negative rods. Study Design: Experimental study. Place and Duration of Study: Department of Microbiology, University of Health Sciences Lahore, from Jul 2011 to Jun 2012. Material and Methods: A total of 157 isolates of S. typhi were collected from different hospitals of Lahore and kept stored at -80 degree C. Morphological, biochemical and serological identification and antibiotic susceptibility testing of the isolates was carried out as per CLSI 2011 guidelines. Agar dilution method was used for the determination of MICs of MGO, using a multi-point inoculator. The data was compiled and results were determined using SPSS version 17. Results: Ninety-seven out of 157 isolates (61.8%) were MDR S. Typhi, while 60 (38.2%) were non-MDR S. Typhi. MIC90 of MGO against MDR S. Typhi isolates was (0.20 mg/mL; 2.8 mM), against non-MDR S. Typhi and Gram negative rods each, it was (0.21 mg/mL; 3.0 mM). When MICs of MGO against MDR S. Typhi group were compared to those of non-MDR S. Typhi group, the p-value was 0.827 (p>0.05; statistically insignificant). Whereas, the p-value of MICs of MGO against MDR S. Typhi group was 0.023 (p<0.05; statistically significant) when compared to gram negative rods group. Conclusion: MGO has good antibacterial activity against MDR and non-MDR S. Typhi, and other genera of Gram negative rods. (author)

Salmonellae carrier status of food vendors in Kumasi, Ghana | Feglo ...

African Journals Online (AJOL)

230 females of 28 males) healthy food vendors for Salmonella typhi, and S. paratyphi A, B, and C, using stool culture, the widal test, and standard microbiological identification methods. Main outcome measures: Prevalence of chronic typhoidal ...

[Drug tolerance and PFGE molecular typing of Salmonella paratyphi A isolated in Dengfeng, Henan province, 2009-2015].

Science.gov (United States)

Zhao, J Y; Zhang, S Y; Mu, Y J; Zhang, B F; Xia, S L; Huang, X Y; Xu, B L

2016-05-01

To investigate the drug tolerance and PFGE patterns of Salmonella(S.)paratyphi A strains isolated from sentinel hospitals in Dengfeng, Henan province, during 2009-2015. Venous blood samples were collected from paratyphoid patients and cultured in double phase blood culture bottle. Suspicious strains were identified and used for Salomonella. O antigen and H1/2 phase flagellum-induced serum agglutination test with API20E biochemical systems and SSI Salmonella typing sera. According to Salmonella molecular typing and K-B drug susceptibility testing method published by PulseNet China bacterial infectious disease monitoring network and USA Clinical and Laboratory Standards Institute, we analyzed the drug susceptibility and PFGE molecule characteristics of S. paratyphi A strains isolated from the patients. A total of 126 strains of S. paratyphi A were isolated from 248 blood samples, the antigen modes of them were 1, 2, 12:a:-. The resistance rate of 126 strains of S. paratyphi A was 83.3% to ampicillin; 29.4% to ceftazidime, 31.2% to cefotaxime, 17.5% to cefepime; 62.6% to nalidixic acid; 19.3% to ciprofloxacin, 26.4% to norfloxacin; 22.8% to gentamicin, 47.9% to streptomycin; 19.2% to chloramphenicol, 24.2% to methicillin benzyl ammonium, 58.6% to compound sulfamethoxazole and 46.7% to tetracycline. The 126 strains of S. paratyphi A had different levels of resistance to 8 kinds of antibiotics, 109 strains were multidrug resistant(86.5%), 9 strains were resistant to 2-3 kinds of antibiotics(7.1%), 76 strains were resistant to 5-8 kinds of antibiotics(60.3%), 17 strains were resistant to 9-10 kinds of antibiotics(13.5%), 7 strains were resistant to 11-12 kinds of antibiotics(5.6%). The 126 strains of S. paratyphi A were divided into 14 molecular patterns by digestion with XbaⅠand pulsed field gel electrophoresis. The antibiotics resistance to third generation cephalosporin(CAZ, CTX), one generation and three generation of quinolones(NAL, CIP, NOR)and aminoglycosides

AND Citrus senensis PEEL EXTRACTS ON Aeromonas hydrophila ...

African Journals Online (AJOL)

DR. AMINU

the two plant extracts against some clinical isolates: six Salmonella paratyphi B, one S. typhi and three A. ... century make the medicines and drugs of vegetables origin lost their ... in preventing heart disease. ... is a remedy for edema.

blaCTX-M-I group extended spectrum beta lactamase-producing Salmonella typhi from hospitalized patients in Lagos, Nigeria

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Akinyemi KO

2015-05-01

Full Text Available Kabiru O Akinyemi,1 Bamidele A Iwalokun,2 Olajide O Alafe,1 Sulaiman A Mudashiru,1 Christopher Fakorede,11Department of Microbiology, Lagos State University, Ojo, Lagos, Nigeria; 2Biochemistry and Nutrition Division, Nigerian Institute of Medical Research, Yaba, Lagos, NigeriaPurpose: The global spread of blaCTX-M-I extended-spectrum beta-lactamase (ESBL-producing Salmonella spp. remains a major threat to treatment and control. Evidence of emergence and spread of this marker are lacking in Nigeria. This study investigated blaCTX-M-I ESBL production among Salmonella isolates from hospitalized patients.Methods: Patients (158 total made up of two groups were evaluated. Group A was composed of 135 patients with persistent pyrexia and group B was composed of 23 gastroenteritis patients and their stool samples. Samples were cultured, and isolates were identified and were subjected to antibiotic susceptibility testing by standard methods. Isolates were further screened for ESBL production, blaCTX-M-I genes and transferability by double disk synergy test, plasmid extraction, polymerase chain reaction, and conjugation experiment.Results: Thirty-five (25.9% Salmonella isolates were identified from group A, of which 74.3% were S. typhi, 22.9% were S. paratyphi and two (5.7% were invasive non-typhoidal S. enteritidis. Nine Plasmodium falciparum infections were recorded, four of which were identified as co-infections with typhoidal Salmonella. Only two (8.7% S. enteritidis samples were obtained from group B (P>0.05. A total of 24 isolates were ESBL-positive, eliciting resistance to five to seven antibiotics, and were multiple-drug resistant. ESBL production due to the blaCTX-M-I gene cluster was detected in eleven (45.8% Salmonella isolates. Nine (81.8% of the eleven blaCTX-M-I ESBL producers were S. typhi and two (18.2% isolates were S. enteritidis. Four of nine S. typhi blaCTX-M-I ESBL-producing strains harbored 23 kb self-transmissible plasmid that was co

Outbreaks of Salmonella paratyphi A in a commercial poultry farm in ...

African Journals Online (AJOL)

An outbreak of Salmonella paratyphi A in a commercial poultry farm in Ibadan is hereby reported. The clinical findings manifested by the birds were reduced appetite, increased water consumption and passed yellowish green stool. There was decreased egg production, prostration and death. Morbidity was 50% while ...

Diarrhea associated with typhoid fever

NARCIS (Netherlands)

Roy, S. K.; Speelman, P.; Butler, T.; Nath, S.; Rahman, H.; Stoll, B. J.

1985-01-01

To study the pathogenesis of diarrhea occurring with typhoid fever, we selected 42 patients with diarrhea and blood cultures positive for Salmonella typhi or Salmonella paratyphi A, but without diarrheal copathogens, for measurement of stool output and examination of fecal composition. The mean

Ludwig′s angina by Salmonella Typhi: A clinical dilemma

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R K Mahajan

2015-01-01

Full Text Available Salmonella Typhi has rarely been associated with focal abscesses; and in literature, there is no evidence of its association with abscesses in the neck spaces. Ability of Salmonella Typhi to invade and localise in the neck spaces not only poses a diagnostic challenge but also underscores the necessity to understand the mechanisms that facilitate Salmonella Typhi to establish infections at sites completely non-traditional to the organism.

Cell-free culture supernatant of Bifidobacterium breve CNCM I-4035 decreases pro-inflammatory cytokines in human dendritic cells challenged with Salmonella typhi through TLR activation.

Science.gov (United States)

Bermudez-Brito, Miriam; Muñoz-Quezada, Sergio; Gomez-Llorente, Carolina; Matencio, Esther; Bernal, Maria J; Romero, Fernando; Gil, Angel

2013-01-01

Dendritic cells (DCs) constitute the first point of contact between gut commensals and our immune system. Despite growing evidence of the immunomodulatory effects of probiotics, the interactions between the cells of the intestinal immune system and bacteria remain largely unknown. Indeed,, the aim of this work was to determine whether the probiotic Bifidobacterium breve CNCM I-4035 and its cell-free culture supernatant (CFS) have immunomodulatory effects in human intestinal-like dendritic cells (DCs) and how they respond to the pathogenic bacterium Salmonella enterica serovar Typhi, and also to elucidate the molecular mechanisms involved in these interactions. Human DCs were directly challenged with B. breve/CFS, S. typhi or a combination of these stimuli for 4 h. The expression pattern of genes involved in Toll-like receptor (TLR) signaling pathway and cytokine secretion was analyzed. CFS decreased pro-inflammatory cytokines and chemokines in human intestinal DCs challenged with S. typhi. In contrast, the B. breve CNCM I-4035 probiotic strain was a potent inducer of the pro-inflammatory cytokines and chemokines tested, i.e., TNF-α, IL-8 and RANTES, as well as anti-inflammatory cytokines including IL-10. CFS restored TGF-β levels in the presence of Salmonella. Live B.breve and its supernatant enhanced innate immune responses by the activation of TLR signaling pathway. These treatments upregulated TLR9 gene transcription. In addition, CFS was a more potent inducer of TLR9 expression than the probiotic bacteria in the presence of S. typhi. Expression levels of CASP8 and IRAK4 were also increased by CFS, and both treatments induced TOLLIP gene expression. Our results indicate that the probiotic strain B. breve CNCM I-4035 affects the intestinal immune response, whereas its supernatant exerts anti-inflammatory effects mediated by DCs. This supernatant may protect immune system from highly infectious agents such as Salmonella typhi and can down-regulate pro

Cell-free culture supernatant of Bifidobacterium breve CNCM I-4035 decreases pro-inflammatory cytokines in human dendritic cells challenged with Salmonella typhi through TLR activation.

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Miriam Bermudez-Brito

Full Text Available Dendritic cells (DCs constitute the first point of contact between gut commensals and our immune system. Despite growing evidence of the immunomodulatory effects of probiotics, the interactions between the cells of the intestinal immune system and bacteria remain largely unknown. Indeed,, the aim of this work was to determine whether the probiotic Bifidobacterium breve CNCM I-4035 and its cell-free culture supernatant (CFS have immunomodulatory effects in human intestinal-like dendritic cells (DCs and how they respond to the pathogenic bacterium Salmonella enterica serovar Typhi, and also to elucidate the molecular mechanisms involved in these interactions. Human DCs were directly challenged with B. breve/CFS, S. typhi or a combination of these stimuli for 4 h. The expression pattern of genes involved in Toll-like receptor (TLR signaling pathway and cytokine secretion was analyzed. CFS decreased pro-inflammatory cytokines and chemokines in human intestinal DCs challenged with S. typhi. In contrast, the B. breve CNCM I-4035 probiotic strain was a potent inducer of the pro-inflammatory cytokines and chemokines tested, i.e., TNF-α, IL-8 and RANTES, as well as anti-inflammatory cytokines including IL-10. CFS restored TGF-β levels in the presence of Salmonella. Live B.breve and its supernatant enhanced innate immune responses by the activation of TLR signaling pathway. These treatments upregulated TLR9 gene transcription. In addition, CFS was a more potent inducer of TLR9 expression than the probiotic bacteria in the presence of S. typhi. Expression levels of CASP8 and IRAK4 were also increased by CFS, and both treatments induced TOLLIP gene expression. Our results indicate that the probiotic strain B. breve CNCM I-4035 affects the intestinal immune response, whereas its supernatant exerts anti-inflammatory effects mediated by DCs. This supernatant may protect immune system from highly infectious agents such as Salmonella typhi and can down

PanCoreGen - Profiling, detecting, annotating protein-coding genes in microbial genomes.

Science.gov (United States)

Paul, Sandip; Bhardwaj, Archana; Bag, Sumit K; Sokurenko, Evgeni V; Chattopadhyay, Sujay

2015-12-01

A large amount of genomic data, especially from multiple isolates of a single species, has opened new vistas for microbial genomics analysis. Analyzing the pan-genome (i.e. the sum of genetic repertoire) of microbial species is crucial in understanding the dynamics of molecular evolution, where virulence evolution is of major interest. Here we present PanCoreGen - a standalone application for pan- and core-genomic profiling of microbial protein-coding genes. PanCoreGen overcomes key limitations of the existing pan-genomic analysis tools, and develops an integrated annotation-structure for a species-specific pan-genomic profile. It provides important new features for annotating draft genomes/contigs and detecting unidentified genes in annotated genomes. It also generates user-defined group-specific datasets within the pan-genome. Interestingly, analyzing an example-set of Salmonella genomes, we detect potential footprints of adaptive convergence of horizontally transferred genes in two human-restricted pathogenic serovars - Typhi and Paratyphi A. Overall, PanCoreGen represents a state-of-the-art tool for microbial phylogenomics and pathogenomics study. Copyright © 2015 Elsevier Inc. All rights reserved.

PanCoreGen – profiling, detecting, annotating protein-coding genes in microbial genomes

Science.gov (United States)

Bhardwaj, Archana; Bag, Sumit K; Sokurenko, Evgeni V.

2015-01-01

A large amount of genomic data, especially from multiple isolates of a single species, has opened new vistas for microbial genomics analysis. Analyzing pan-genome (i.e. the sum of genetic repertoire) of microbial species is crucial in understanding the dynamics of molecular evolution, where virulence evolution is of major interest. Here we present PanCoreGen – a standalone application for pan- and core-genomic profiling of microbial protein-coding genes. PanCoreGen overcomes key limitations of the existing pan-genomic analysis tools, and develops an integrated annotation-structure for species-specific pan-genomic profile. It provides important new features for annotating draft genomes/contigs and detecting unidentified genes in annotated genomes. It also generates user-defined group-specific datasets within the pan-genome. Interestingly, analyzing an example-set of Salmonella genomes, we detect potential footprints of adaptive convergence of horizontally transferred genes in two human-restricted pathogenic serovars – Typhi and Paratyphi A. Overall, PanCoreGen represents a state-of-the-art tool for microbial phylogenomics and pathogenomics study. PMID:26456591

Analysis of Salmonella enterica serotype paratyphi A gene expression in the blood of bacteremic patients in Bangladesh.

Directory of Open Access Journals (Sweden)

Alaullah Sheikh

2010-12-01

Full Text Available Salmonella enterica serotype Paratyphi A is a human-restricted cause of paratyphoid fever, accounting for up to a fifth of all cases of enteric fever in Asia.In this work, we applied an RNA analysis method, Selective Capture of Transcribed Sequences (SCOTS, and cDNA hybridization-microarray technology to identify S. Paratyphi A transcripts expressed by bacteria in the blood of three patients in Bangladesh. In total, we detected 1,798 S. Paratyphi A mRNAs expressed in the blood of infected humans (43.9% of the ORFeome. Of these, we identified 868 in at least two patients, and 315 in all three patients. S. Paratyphi A transcripts identified in at least two patients encode proteins involved in energy metabolism, nutrient and iron acquisition, vitamin biosynthesis, stress responses, oxidative stress resistance, and pathogenesis. A number of detected transcripts are expressed from PhoP and SlyA-regulated genes associated with intra-macrophage survival, genes contained within Salmonella Pathogenicity Islands (SPIs 1-4, 6, 10, 13, and 16, as well as RpoS-regulated genes. The largest category of identified transcripts is that of encoding proteins with unknown function. When comparing levels of bacterial mRNA using in vivo samples collected from infected patients to samples from in vitro grown organisms, we found significant differences for 347, 391, and 456 S. Paratyphi A transcripts in each of three individual patients (approximately 9.7% of the ORFeome. Of these, expression of 194 transcripts (4.7% of ORFs was concordant in two or more patients, and 41 in all patients. Genes encoding these transcripts are contained within SPI-1, 3, 6 and 10, PhoP-regulated genes, involved in energy metabolism, nutrient acquisition, drug resistance, or uncharacterized genes. Using quantitative RT-PCR, we confirmed increased gene expression in vivo for a subset of these genes.To our knowledge, we describe the first microarray-based transcriptional analysis of a pathogen

Current trends of antimicrobial susceptibility of typhoidal salmonellae isolated at tertiary care hospital

International Nuclear Information System (INIS)

Zehra, N.M.; Irfan, F.

2017-01-01

To determine the current trend of antimicrobial susceptibility of typhoidal Salmonellae. Study Design: Descriptive cross-sectional study. Place and Duration of Study: The study was carried out in the Department of Microbiology, PNS Shifa Hospital, Karachi, from January 2014 to December 2015. Methodology: Blood culture samples received from the wards and outpatient departments were included. Isolates of Salmonella were dealt with standard microbiological procedures. The antimicrobial sensitivity against the typhoidal Salmonellae was determined using Kirby-Bauer disc diffusion method as per the guidelines of Clinical and Laboratory Standards Institute (2013). Results: A total of 460 typhoidal Salmonellae were isolated; out of which 270 were Salmonella typhi and 190 were Salmonella paratyphiA. The percentage of MDR isolates of S. typhi was 57% and that of S. paratyphiA was 42%. None of the isolates were resistant to ceftriaxone, while sensitivity to ciprofloxacin (07% and 0% for S. typhiand S. paratyphiA, respectively) was very low. Conclusion: There is high percentage of MDR isolates of typhoidal Salmonellae in our region. The antimicrobial sensitivity of typhoidal Salmonellae to conventional agent has not improved enough to recommend their empirical use. There is almost complete resistance to fluoroquinolones as well, leaving very limited available treatment options. (author)

Changes in the prevalence of Salmonella serovars associated swine production and correlations of avian, bovine and swine-associated serovars with human-associated serovars in the United States (1997-2015).

Science.gov (United States)

Yuan, C; Krull, A; Wang, C; Erdman, M; Fedorka-Cray, P J; Logue, C M; O'Connor, A M

2018-04-23

As Salmonella enterica is an important pathogen of food animals, surveillance programmes for S. enterica serovars have existed for many years in the United States. Surveillance programmes serve many purposes, one of which is to evaluate alterations in the prevalence of serovars that may signal changes in the ecology of the target organism. The primary aim of this study was to evaluate changes in the proportion of S. enterica serovars isolated from swine over a near 20-year observation period (1997-2015) using four longitudinal data sets from different food animal species. The secondary aim was to evaluate correlations between changes in S. enterica serovars frequently recovered from food animals and changes in S. enterica serovars associated with disease in humans. We found decreasing proportions of S. enterica serovar Typhimurium, serovar Derby and serovar Heidelberg and increasing proportions of S. enterica serovar 4,[5],12:i:-, serovar Infantis and serovar Johannesburg in swine over time. We also found positive correlations for the yearly changes in S. enterica serovar 4,[5],12:i:-, serovar Anatum and serovar Johannesburg between swine and human data; in S. enterica Worthington between avian and human data; and in S. enterica serovar 4,[5],12:i:- between bovine and human data. We found negative correlations for the yearly changes in S. enterica serovar 4,[5],12:i:- and serovar Johannesburg between avian and human data. © 2018 Blackwell Verlag GmbH.

Pathogenicity of Salmonella Paratyphi A in Pullets

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A. O. Ogunleye

2006-01-01

Full Text Available The pathogenicity of Salmonella Paratyphi A isolated at Debiwise Poultry Farm during a fulminating outbreak was tested. Twenty 16-week-old pullets were inoculated orally with 0.5 ml of 1.3 x 108 CFU/bird Salmonella Paratyphi A, while 20 others of the same age served as uninfected control. By the fourth day postinoculation (p.i. dullness, ruffled and unkempt feathers, somnolence, yellowish- green diarrhea, decreased water and feed consumption were observed in the infected birds; mortality was 95% by day 16 p.i. Remarkable pathological lesions were recorded between days 7 and 14 p.i. The liver was moderately enlarged, with multiple necrotic foci, and dark brown to bronze coloration. The kidneys were swollen, with widespread focal pale necrotic areas, while the spleen was slightly enlarged. Histopathologically, the proventriculus showed focal glandular necrosis, mononuclear cell infiltration and moderate perivascular leucocytic infiltration. There was mucosal hemorrhage, matting of intestinal villi with reduction of villous height and presence of epithelial debris in the lumen with increased leucocytic infiltration in the lamina propriae. The liver showed moderate, diffuse congestion of the sinusoid and central veins, as well as multiple foci of necrosis of hepatocytes, mononuclear infiltration and perivascular cellular infiltration. There was diffuse lymphoid depletion in the nodule and around the splenic arterioles as well as throughout the parenchyma. The kidneys were congested with tubular epithelial necrosis characterized by karyorrhexis of the nuclei. The organism was recovered from the liver, spleen, heart, heart blood and bone marrow of infected birds. No clinical sign or gross lesion or pathogen was observed in the negative control.

Molecular detection of Rickettsia typhi in cats and fleas.

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Maria Mercedes Nogueras

Full Text Available BACKGROUND: Rickettsiatyphi is the etiological agent of murine typhus (MT, a disease transmitted by two cycles: rat-flea-rat, and peridomestic cycle. Murine typhus is often misdiagnosed and underreported. A correct diagnosis is important because MT can cause severe illness and death. Our previous seroprevalence results pointed to presence of human R. typhi infection in our region; however, no clinical case has been reported. Although cats have been related to MT, no naturally infected cat has been described. The aim of the study is to confirm the existence of R. typhi in our location analyzing its presence in cats and fleas. METHODOLOGY/PRINCIPAL FINDINGS: 221 cats and 80 fleas were collected from Veterinary clinics, shelters, and the street (2001-2009. Variables surveyed were: date of collection, age, sex, municipality, living place, outdoor activities, demographic area, healthy status, contact with animals, and ectoparasite infestation. IgG against R. typhi were evaluated by indirect immunofluorescence assay. Molecular detection in cats and fleas was performed by real-time PCR. Cultures were performed in those cats with positive molecular detection. Statistical analysis was carried out using SPSS. A p < 0.05 was considered significant. Thirty-five (15.8% cats were seropositive. There were no significant associations among seropositivity and any variables. R. typhi was detected in 5 blood and 2 cultures. High titres and molecular detection were observed in stray cats and pets, as well as in spring and winter. All fleas were Ctenocephalides felis. R. typhi was detected in 44 fleas (55%, from shelters and pets. Co-infection with R. felis was observed. CONCLUSIONS: Although no clinical case has been described in this area, the presence of R. typhi in cats and fleas is demonstrated. Moreover, a considerable percentage of those animals lived in households. To our knowledge, this is the first time R. typhi is detected in naturally infected cats.

( Allium sativum ) on Salmonella typhi infection, gastrointestinal flora ...

African Journals Online (AJOL)

The effect of consumption of garlic (Allium sativum) in treating Salmonella typhi infection and on the gastrointestinal flora and hematological parameters of rats was investigated. Crude garlic extract inhibited the growth of S. typhi on agar plate with a zone of inhibition averaging 23.8 mm in diameter using the agar diffusion ...

A Rare Case of Salmonella typhi Meningitis in an Eleven Month Old ...

African Journals Online (AJOL)

Non-typhoidal Salmonella are infrequent causes of childhood meningitis. Most reports of Salmonella typhi meningeal infections are confined to neonates. A rare instance of S. typhi in an otherwise healthy eleven month old infant is being reported. Keywords: Salmonella typhi, meningitis, infant.

BACTERICIDAL ACTIVITY OF HUMAN SERA AGAINST ...

African Journals Online (AJOL)

hi-tech

East African Medical Journal Vol. 77 No. 12 December 2000. BACTERICIDAL ACTIVITY OF HUMAN SERA AGAINST SALMONELLA TYPHI AND SALMONELLA PARATYPHI A, B, C. E.O. Igumbor, BSc, MSc, PhD, Department of Medical Microbiology, School of Medicine, University of Zimbabwe P.O. Box Al78, Avondale, ...

Comparison of the sensitivity of typhi dot test with blood culture in typhoid

Energy Technology Data Exchange (ETDEWEB)

Rizvi, Q [Hamdard College of Medicine, Karachi (Pakistan). Dept. of Pharmacology

2006-10-15

To evaluate the sensitivity of Typhi Dot test in comparison to Blood Culture for the diagnosis of Typhoid Fever in our setup. Fifty patients who fulfilled the clinical criteria of having Typhoid Fever. The data of all the patients was documented, and they were submitted to the Typhi Dot and Blood Culture tests, apart from other routine investigations. Out of the total 50 patients, 47(94%) had their Blood Culture positive for Typhoid bacillus, while in 49 (98%) the Typhi Dot test was positive. Two patients which were found positive on Typhi dot test, gave negative results on Blood Culture. One patient with the signs and symptoms of Typhoid Fever was found neither positive on Typhi Dot test nor upon Blood Culture. There was no significant difference between the results of Blood Culture and Typhi Dot test in the diagnosis of Typhoid Fever. However, Typhi Dot has the advantages of being less expensive and quicker in giving results with excellent sensitivity. (author)

Comparison of the sensitivity of typhi dot test with blood culture in typhoid

International Nuclear Information System (INIS)

Rizvi, Q.

2006-01-01

To evaluate the sensitivity of Typhi Dot test in comparison to Blood Culture for the diagnosis of Typhoid Fever in our setup. Fifty patients who fulfilled the clinical criteria of having Typhoid Fever. The data of all the patients was documented, and they were submitted to the Typhi Dot and Blood Culture tests, apart from other routine investigations. Out of the total 50 patients, 47(94%) had their Blood Culture positive for Typhoid bacillus, while in 49 (98%) the Typhi Dot test was positive. Two patients which were found positive on Typhi dot test, gave negative results on Blood Culture. One patient with the signs and symptoms of Typhoid Fever was found neither positive on Typhi Dot test nor upon Blood Culture. There was no significant difference between the results of Blood Culture and Typhi Dot test in the diagnosis of Typhoid Fever. However, Typhi Dot has the advantages of being less expensive and quicker in giving results with excellent sensitivity. (author)

Analysis of Genes expression regulation controlled by luxS/AI-2 in Salmonella enterica serovar Typhi%LuxS/AI-2对伤寒沙门菌基因表达的调节

Institute of Scientific and Technical Information of China (English)

罗哲; 王敏; 杜鸿; 王菲; 孟彦辰; 倪斌; 徐顺高; 黄新祥

2011-01-01

Objective : To elucidate the influence of LuxS on gene expression regulation of Salmonella enterica serovar Typhi (S. Typhi) at mid-log phase in the presence of glucose . Methods: The luxS deleted mutant of S. Typhi was prepared by the homologous recombination mediatecl by suicide plasmid ; the differences of growth and motility between wild -type ( WT) and mutant were compared ; luminescence assays were performed in WT and mutant at different growth phases in the presence and absence of glucose with reporter strain Vibrio harveyi BB170; the difference of gene expression profiles between the WT and the luxS mutant at mid-log phage in the presence of glucose was investigated by genomic microarray assay ; qRT-PCR was performed to validate the results of microarray assay . Results : The luxS deleted mutant of S. Typhi was constructed successfully ; luxS gene had effect on the bacterial motility but not on the bacterial growth ; the luminescence of WT was higher at any growth phases in the presence of glucose than in its absence and reached the maximum at mid -log phase in the presence of glucose , while the mutant did not produce luminescence in both the presence and absence of glucose at any growth phases ; gene expression profiles analysis revealed that expression of 47 and 27 genes were induced and decreased , respectively , in the luxS mutant at mid-log phases in the presence of glucose . The results of qRT-PCR are similar with that of genomic assay. Conclusion: The luxS gene of S. Typhi was involved in the synthesis of AI -2 and played a vital role in genes expression regulation at mid -log phase.%目的:探讨伤寒沙门菌luxS基因在葡萄糖存在下对细菌对数生长中期基因表达调控的影响.方法:应用自杀质粒介导的同源重组方法制备伤寒沙门菌luxS基因缺陷变异株;比较野生株与缺陷株的生长情况及动力差异;用哈氏弧菌BB170�

Interferon-γ and proliferation responses to Salmonella enterica Serotype Typhi proteins in patients with S. Typhi Bacteremia in Dhaka, Bangladesh.

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Alaullah Sheikh

2011-06-01

Full Text Available Salmonella enterica serotype Typhi is a human-restricted intracellular pathogen and the cause of typhoid fever. Cellular immune responses are required to control and clear Salmonella infection. Despite this, there are limited data on cellular immune responses in humans infected with wild type S. Typhi.For this work, we used an automated approach to purify a subset of S. Typhi proteins identified in previous antibody-based immuno-affinity screens and antigens known to be expressed in vivo, including StaF-putative fimbrial protein-STY0202, StbB-fimbrial chaperone-STY0372, CsgF-involved in curli production-STY1177, CsgD- putative regulatory protein-STY1179, OppA-periplasmic oligopeptide binding protein precursor-STY1304, PagC-outer membrane invasion protein-STY1878, and conserved hypothetical protein-STY2195; we also generated and analyzed a crude membrane preparation of S. Typhi (MP. In comparison to samples collected from uninfected Bangladeshi and North American participants, we detected significant interferon-γ responses in PBMCs stimulated with MP, StaF, StbB, CsgF, CsgD, OppA, STY2195, and PagC in patients bacteremic with S. Typhi in Bangladesh. The majority of interferon-γ expressing T cells were CD4 cells, although CD8 responses also occurred. We also assessed cellular proliferation responses in bacteremic patients, and confirmed increased responses in infected individuals to MP, StaF, STY2195, and PagC in convalescent compared to acute phase samples and compared to controls. StaF is a fimbrial protein homologous to E. coli YadK, and contains a Pfam motif thought to be involved in cellular adhesion. PagC is expressed in vivo under the control of the virulence-associated PhoP-regulon required for intra-macrophage survival of Salmonella. STY2195 is a conserved hypothetical protein of unknown function.This is the first analysis of cellular immune responses to purified S. Typhi antigens in patients with typhoid fever. These results indicate

EFEKTIVITAS AIR REBUSAN DAUN BINAHONG (Anredera cordifolia TERHADAP PERTUMBUHAN Salmonella typhi

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Ratih Dewi Dwiyanti

2015-06-01

Full Text Available Abstract: Typhus is one of acute febrile illness caused by the bacterium Salmonella typhi. Treatment of typhoid fever usually use antibiotics, the use of antibiotics can cause side effects. People today are using treatment with natural ingredients, one of which is Binahong (Anredera cordifolia compounds containing alkaloids, polyphenols, flavonoids, saponin, and anthraquinone is efficacious as an antibacterial. This study aims to determine the effectiveness of the water decoction of leaves Binahong against Salmonella typhi growth in vitro. This type of research is true experiment with posttest study design Only Control Group Design and methods used are diffusion (wells with 5 treatment. The concentration of the cooking water leaves the dgunakan Binahong is 20%, 40%, 60%, 80% and 100%. The result showed inhibition zone water decoction of the leaves Binahong against Salmonella typhi at a concentration of 20%, 40%, 60%, 80% is 0 mm, whereas at 100% concentration obtained inhibition zone of 11 mm. It is concluded that the water decoction of the leaves Binahong at a concentration of 100% has the ability to inhibit the growth of Salmonella typhi, but these results have not been effective because it is still in the category of resistance. It is suggested for further research to increase the concentration of water decoction of the leaves binahong or use alcohol extract of leaves binahong to inhibit the growth of Salmonella typhi. Keywords: Water decoction of leaves Binahong, Salmonella typhi, antibacterial. Abstrak: Penyakit tifus atau dikenal dengan demam tifoid atau demam enterik adalah salah satu penyakit demam akut yang disebabkan oleh bakteri Salmonella typhi. Pengobatan demam tifoid biasanya menggunakan antibiotik, penggunaan antibiotik dapat menimbulkan efek samping. Masyarakat saat ini banyak menggunakan pengobatan dengan bahan alami, salah satunya adalah Binahong (Anredera cordifolia yang mengandung senyawa Alkaloid, Polifenol, Flavonoid

Radiosensitization of Escherichia coli and Salmonella typhi in presence of active compounds

International Nuclear Information System (INIS)

Lacroix, M.; Chiasson, F.; Borsa, J.; Ouattara, B.

2004-01-01

The radiosensitization of Escherichia coli and Salmonella typhi in ground beef was evaluated in the presence of 18 active compounds. Medium fat ground beef (23% fat) was inoculated with E. coli or S. typhi and each active compound was added separately at various concentrations. For E. coli, the most efficient compounds were trans-cinnamaldehyde, thymol and thyme. For S. typhi, the most efficient compounds was trans-cinnamaldehyde, carvacrol and thymol. The addition of tetrasodium pyrophosphate, carvacrol and ascorbic acid had no effect on the irradiation sensitivity of E. coli. For S. typhi, only ascorbic acid had no effect

Radiosensitization of Escherichia coli and Salmonella typhi in presence of active compounds

Energy Technology Data Exchange (ETDEWEB)

Lacroix, M. E-mail: monique.lacroix@inrs-iaf.uquebec.ca; Chiasson, F.; Borsa, J.; Ouattara, B

2004-10-01

The radiosensitization of Escherichia coli and Salmonella typhi in ground beef was evaluated in the presence of 18 active compounds. Medium fat ground beef (23% fat) was inoculated with E. coli or S. typhi and each active compound was added separately at various concentrations. For E. coli, the most efficient compounds were trans-cinnamaldehyde, thymol and thyme. For S. typhi, the most efficient compounds was trans-cinnamaldehyde, carvacrol and thymol. The addition of tetrasodium pyrophosphate, carvacrol and ascorbic acid had no effect on the irradiation sensitivity of E. coli. For S. typhi, only ascorbic acid had no effect.

Characterization of Isolates of Salmonella enterica Serovar Stanley, a Serovar Endemic to Asia and Associated with Travel

DEFF Research Database (Denmark)

Hendriksen, Rene S.; Le Hello, Simon; Bortolaia, Valeria

2012-01-01

Salmonella enterica serovar Stanley (S. Stanley) is a common serovar in Southeast Asia and was the second most common serovar implicated in human salmonellosis in Thailand in the years 2002 to 2007. In contrast, this serovar is relatively uncommon in Europe. The objective of this study was to cha...

An atypical presentation of salmonella typhi - A case report

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Jayakumar K

2003-01-01

Full Text Available Breast abscess due to Salmonella typhi is an extremely rare occurrence. A lady with a lump in the left breast was diagnosed to have a fibroadenoma and was subjected to a surgical procedure. She was found to have an abscess due to Salmonella typhi as confirmed by conventional bacteriological methods. She was treated with ciprofloxacin and responded favourably.

A case of injection abscess due to salmonella typhi

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Raghunath R

2003-01-01

Full Text Available To the best of our knowledge, injection abscess due to Salmonella typhi has not been reported earlier. A patient with fever of unknown origin was diagnosed as suffering from typhoid fever, administered a course of ceftrioxone but patient developed an injection abscess due to S.typhi, abscess was drained and patient was started on ciprofloxacin to which he responded favourably.

IMPACT OF FOOD AND FOLATE SUPPLEMENTATION DURING Salmonella TYPHI INFECTION IN Caenorhabditis elegans

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Bhagavathi Sundaram Sivamaruthi

2012-06-01

Full Text Available Caenorhabditis elegans is an instructive and suitable model for studying pathogenesis of almost all human pathogens. Salmonella Typhi is gram-negative facultative intracellular anaerobe that causes several pathetic infections. Necessary enriched nutrient ingestion during pathological conditions may reduce the harshness of the infection. We investigated the impact of folate and food supplementation during S. Typhi infection on the model system, C. elegans. Our data indicated that folate supplementation (10 µg increases the lifespan of S. Typhi infected C. elegans up to 20%. In combination with laboratory food source E. coli OP50, folate increases the infected the worm’s lifespan to 40%. The wild type C. elegans infected by S. Typhi died with the LT50 of 60 ± 12 h. The LT50 of S. Typhi infected folt-1 mutant strain VC959 was 96 ± 6 h. However, the folate supplemented mutant worms exhibited an extended life with LT50 of 120 ± 6 h. The short time exposure and pharyngeal pumping studies confirmed that folt-1 mutant worm exhibited increased survival rate during pathogenic course at significant level when compared to wild-type. Our data revealed that folt-1 plays a significant role in host defense system against S. Typhi infection and the folate supplementation in combination with food increases the host survival during S. Typhi infection.

the developme ... ta .. \\~ production of typhoid fever vaccines toxicity ...

African Journals Online (AJOL)

BSN

Sixty-six different types of ~"?hoid vaccines were prepared using three adjuvants and using both local and imported suams of Salmonella typhi and Salmonella paratyphi A, B, C. About 3,960 mice were used at the ;a:.e of 60 mice per vaccine. The mice were vaccinated intraperitonially with 0.5m1 of sen.le batch of vaccines.

Occurrence of extended-spectrum and AmpC β-lactamases in multiple drug resistant Salmonella isolates from clinical samples in Lagos, Nigeria

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Akinyemi KO

2017-01-01

Full Text Available KO Akinyemi,1 Bamidele Abiodun Iwalokun,2 Akeeb O Bola Oyefolu,1 CO Fakorede1 1Department of Microbiology, Lagos State University, Ojo, 2Molecular Biology and Biotechnology Division, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria Purpose: Salmonella spp. are important foodborne pathogens exhibiting increasing resistance to antimicrobial drugs. Resistance to broad-spectrum β-lactams, mediated by extended-spectrum β-lactamase (ESBL and AmpC β-lactamase enzymes is fast spreading and has had negative impacts on the clinical outcomes, particularly on third-generation cephalosporins. This study investigated the carriage of AmpC gene among multidrug-resistant Salmonella spp. from Lagos, Nigeria. Methods: Forty Salmonella spp. from clinical samples (S. typhi = 13; S. typhimurium = 10; S. enteritidis = 8; S. choleraesuis = 5; S. paratyphi = 4 were subjected to in vitro susceptibility test by disk diffusion methods. Isolates that were resistant to cefoxitin and third-generation cephalosporins were screened for ESBL (Double Disk Synergy Test Method and AmpC enzyme (AmpC disk test production. Detection of AmpC fox gene was carried out by polymerase chain reaction. Results: Thirty-two (80% of the Salmonella isolates were cefoxitin resistant. Plasmid-mediated AmpC β-lactamase and ESBL enzymes were recorded in 10/40 (25% and 16/40 (40% of the Salmonella isolates, respectively. Specifically, 16/40 (40% of the Salmonella isolates possessed 380 bp AmpC fox gene, with the highest occurrence found in S. typhi strains (43.8% followed by S. typhimurium (25%. There was no AmpC fox gene detected in S. paratyphi strains. Interestingly, coproduction of enzymes occurred in some of the isolates, raising fears of resistance to a multitude of antibiotics in the treatment of bacterial infections. Conclusion: Emergence of AmpC β-lactamase–producing Salmonella isolates in our environment was recorded for the first time, raising concern on increased

Modification Of Carry-Blair Transport Media For Storage Salmonella typhi

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Yati Supriatin

2016-09-01

Full Text Available The aim of this study was to determine transport media modification as alternative media to replace Carry Blair. One type of transport media that often use to carry faeces specimens suspected to contain Salmonella typhi is Carry-Blair media. Studies have been conducted experimentally by storing Salmonella typhi on alternative transport media with Peptone composition, disodium Phosphate, Sodium chloride, Calcium chloride, which is made using a semi-solid and Carry-Blair as a control. Three variety of storage was done (0 hour,6 hours,9 hours at a temperature 4⁰-8⁰C and then Salmonella typhi was inoculated in Salmonella Shigella Agar using spread plate technique incubated during 24 hours at 37⁰C, counted the number of colonies by the plate count method using the colony counter. The results of ANOVA could be concluded that modification media could be use as alternative media replace Carry-Blair at 6 hours. Based on regression correlation test was assumed that the Salmonella typhi bacteria still life at less than 11 hours 54 minutes.

The core proteome and pan proteome of Salmonella Paratyphi A epidemic strains.

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Li Zhang

Full Text Available Comparative proteomics of the multiple strains within the same species can reveal the genetic variation and relationships among strains without the need to assess the genomic data. Similar to comparative genomics, core proteome and pan proteome can also be obtained within multiple strains under the same culture conditions. In this study we present the core proteome and pan proteome of four epidemic Salmonella Paratyphi A strains cultured under laboratory culture conditions. The proteomic information was obtained using a Two-dimensional gel electrophoresis (2-DE technique. The expression profiles of these strains were conservative, similar to the monomorphic genome of S. Paratyphi A. Few strain-specific proteins were found in these strains. Interestingly, non-core proteins were found in similar categories as core proteins. However, significant fluctuations in the abundance of some core proteins were also observed, suggesting that there is elaborate regulation of core proteins in the different strains even when they are cultured in the same environment. Therefore, core proteome and pan proteome analysis of the multiple strains can demonstrate the core pathways of metabolism of the species under specific culture conditions, and further the specific responses and adaptations of the strains to the growth environment.

[Breast abscess with Salmonella typhi and review of the literature].

Science.gov (United States)

Delori, M; Abgueguen, P; Chennebault, J-M; Pichard, E; Fanello, S

2007-11-01

We report the case of a 54-year-old woman who presented with breast abscess, which appeared through a common alimentary toxi-infection with Salmonella Typhi, infection, which implied twelve patients having attended the same restaurant. With around hundred native cases a year in France, typhoid fever is not a very frequent toxi-infection. Among the known extra-intestinal manifestations of Salmonella infections, the breast abscess remains rare and the literature revealed less than ten published cases, including some revealed the disease. In our observation, the imputability of S. Typhi was retained based on the chronology of the clinical signs, specific treatments, and the successful outcome under antibiotherapy, in spite of the negativity of the breast abscess bacteriological samples. We also analyze rare cases of breast abscess due to S. Typhi found in the literature.

Determination of Leptospira borgpetersenii serovar Javanica and Leptospira interrogans serovar Bataviae as the persistent Leptospira serovars circulating in the urban rat populations in Peninsular Malaysia.

Science.gov (United States)

Benacer, Douadi; Mohd Zain, Siti Nursheena; Sim, Shin Zhu; Mohd Khalid, Mohd Khairul Nizam; Galloway, Renee L; Souris, Marc; Thong, Kwai Lin

2016-03-01

Leptospirosis is an emerging infectious disease of global significance, and is endemic in tropical countries, including Malaysia. Over the last decade, a dramatic increase of human cases was reported; however, information on the primary vector, the rat, and the Leptospira serovars circulating among the rat population is limited. Therefore, the present study was undertaken to isolate Leptospira and characterise the serovars circulating in the urban rat populations from selected main cities in Peninsular Malaysia. Rat trappings were carried out between October 2011 to February 2014 in five urban cities which were chosen as study sites to represent different geographical locations in Peninsular Malaysia. Microscopic agglutination test (MAT) and PCR were carried out to identify the Leptospiral serogroup and determine the pathogenic status of the isolates, respectively while pulsed-field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD)-PCR were used to characterize the isolates. Three rat species were identified from the three hundred and fifty seven rats captured with Rattus rattus, being the dominant rat species (285, 80 %) followed by Rattus norgevicus (53, 15 %) and Rattus exulans (19, 5 %). Only 39 samples (11.0 %) were positive by culture and further confirmed as pathogenic Leptospira by PCR. Significant associations were shown between host infection with locality, season, host-age and species. Based on MAT, two serogroups were identified in the population namely; L. borgpetersenii serogroup Javanica (n = 16) and L. interrogans serogroup Bataviae (n = 23). Pulsed-field gel electrophoresis (PFGE) distinguished the two serovars in the urban rat populations: L. borgpetersenii serovar Javanica (41 %), and L. interrogans serovar Bataviae (59 %). RAPD-PCR yielded 14 distinct patterns and was found to be more discriminative than PFGE. This study confirms two Leptospira serovars circulating among the urban rats population in Peninsular

What’s in a Name? Species-Wide Whole-Genome Sequencing Resolves Invasive and Noninvasive Lineages of Salmonella enterica Serotype Paratyphi B

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Thomas R. Connor

2016-08-01

Full Text Available For 100 years, it has been obvious that Salmonella enterica strains sharing the serotype with the formula 1,4,[5],12:b:1,2—now known as Paratyphi B—can cause diseases ranging from serious systemic infections to self-limiting gastroenteritis. Despite considerable predicted diversity between strains carrying the common Paratyphi B serotype, there remain few methods that subdivide the group into groups that are congruent with their disease phenotypes. Paratyphi B therefore represents one of the canonical examples in Salmonella where serotyping combined with classical microbiological tests fails to provide clinically informative information. Here, we use genomics to provide the first high-resolution view of this serotype, placing it into a wider genomic context of the Salmonella enterica species. These analyses reveal why it has been impossible to subdivide this serotype based upon phenotypic and limited molecular approaches. By examining the genomic data in detail, we are able to identify common features that correlate with strains of clinical importance. The results presented here provide new diagnostic targets, as well as posing important new questions about the basis for the invasive disease phenotype observed in a subset of strains.

Detection of Salmonella typhi utilizing bioconjugated fluorescent polymeric nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Jain, Swati, E-mail: swatijain.iitd@gmail.com; Chattopadhyay, Sruti, E-mail: sruticiitd@gmail.com; Jackeray, Richa; Abid, Zainul; Singh, Harpal, E-mail: harpal2000@yahoo.com [Centre for Biomedical Engineering, Indian Institute of Technology-Delhi (India)

2016-05-15

Present work demonstrates effective utilization of functionalized polymeric fluorescent nanoparticles as biosensing probe for the detection of Salmonella typhi bacteria on modified polycarbonate (PC) filters in about 3 h. Antibody modified-PC membranes were incubated with contaminated bacterial water for selective capturing which were detected by synthesized novel bioconjugate probe. Core–shell architecture of polymeric nanoparticles endows them with aqueous stabilization and keto-enolic functionalities making them usable for covalently linking S. typhi antibodies without any crosslinker or activator. Bradford analysis revealed that one nanoparticle has an average of 3.51 × 10{sup −19} g or 21 × 10{sup 4} bound S. typhi Ab molecules. Analysis of the regions of interest (ROI) in fluorescent micrographs of modified fluoroimmunoassay showed higher detection sensitivity of 5 × 10{sup 2} cells/mL due to signal amplification unlike conventional naked dye FITC-Ab conjugate. Fluorescence of pyrene dye remained same on immobilization of biomolecules and nanoparticles showed stable fluorescent intensity under prolong exposure to laser owing to protective polymeric layer allowing accurate identification of bacteria. Surface-functionalized PC matrix and fluorescent label NPs permit covalent interactions among biomolecules enhancing signal acquisitions showing higher detection efficiency as compared to conventional microtiter plate-based system. Our novel immunoassay has the potential to be explored as rapid detection method for identifying S. typhi contaminations in water.Graphical Abstract.

Detection of Salmonella typhi utilizing bioconjugated fluorescent polymeric nanoparticles

International Nuclear Information System (INIS)

Jain, Swati; Chattopadhyay, Sruti; Jackeray, Richa; Abid, Zainul; Singh, Harpal

2016-01-01

Present work demonstrates effective utilization of functionalized polymeric fluorescent nanoparticles as biosensing probe for the detection of Salmonella typhi bacteria on modified polycarbonate (PC) filters in about 3 h. Antibody modified-PC membranes were incubated with contaminated bacterial water for selective capturing which were detected by synthesized novel bioconjugate probe. Core–shell architecture of polymeric nanoparticles endows them with aqueous stabilization and keto-enolic functionalities making them usable for covalently linking S. typhi antibodies without any crosslinker or activator. Bradford analysis revealed that one nanoparticle has an average of 3.51 × 10"−"1"9 g or 21 × 10"4 bound S. typhi Ab molecules. Analysis of the regions of interest (ROI) in fluorescent micrographs of modified fluoroimmunoassay showed higher detection sensitivity of 5 × 10"2 cells/mL due to signal amplification unlike conventional naked dye FITC-Ab conjugate. Fluorescence of pyrene dye remained same on immobilization of biomolecules and nanoparticles showed stable fluorescent intensity under prolong exposure to laser owing to protective polymeric layer allowing accurate identification of bacteria. Surface-functionalized PC matrix and fluorescent label NPs permit covalent interactions among biomolecules enhancing signal acquisitions showing higher detection efficiency as compared to conventional microtiter plate-based system. Our novel immunoassay has the potential to be explored as rapid detection method for identifying S. typhi contaminations in water.Graphical Abstract

Live recombinant Salmonella Typhi vaccines constructed to investigate the role of rpoS in eliciting immunity to a heterologous antigen.

Directory of Open Access Journals (Sweden)

Huoying Shi

2010-06-01

Full Text Available We hypothesized that the immunogenicity of live Salmonella enterica serovar Typhi vaccines expressing heterologous antigens depends, at least in part, on its rpoS status. As part of our project to develop a recombinant attenuated S. Typhi vaccine (RASTyV to prevent pneumococcal diseases in infants and children, we constructed three RASTyV strains synthesizing the Streptococcus pneumoniae surface protein PspA to test this hypothesis. Each vector strain carried ten engineered mutations designed to optimize safety and immunogenicity. Two S. Typhi vector strains (chi9639 and chi9640 were derived from the rpoS mutant strain Ty2 and one (chi9633 from the RpoS(+ strain ISP1820. In chi9640, the nonfunctional rpoS gene was replaced with the functional rpoS gene from ISP1820. Plasmid pYA4088, encoding a secreted form of PspA, was moved into the three vector strains. The resulting RASTyV strains were evaluated for safety in vitro and for immunogenicity in mice. All three RASTyV strains were similar to the live attenuated typhoid vaccine Ty21a in their ability to survive in human blood and human monocytes. They were more sensitive to complement and were less able to survive and persist in sewage and surface water than their wild-type counterparts. Adult mice intranasally immunized with any of the RASTyV strains developed immune responses against PspA and Salmonella antigens. The RpoS(+ vaccines induced a balanced Th1/Th2 immune response while the RpoS(- strain chi9639(pYA4088 induced a strong Th2 immune response. Immunization with any RASTyV provided protection against S. pneumoniae challenge; the RpoS(+ strain chi9640(pYA4088 provided significantly greater protection than the ISP1820 derivative, chi9633(pYA4088. In the pre-clinical setting, these strains exhibited a desirable balance between safety and immunogenicity and are currently being evaluated in a Phase 1 clinical trial to determine which of the three RASTyVs has the optimal safety and

Challenges and Opportunities for Typhoid Fever Control: A Call for Coordinated Action.

Science.gov (United States)

Steele, A Duncan; Hay Burgess, Deborah C; Diaz, Zoey; Carey, Megan E; Zaidi, Anita K M

2016-03-15

The burden of enteric fever caused by Salmonella enterica serovars Typhi and Paratyphi is substantial and has high impact in toddlers and young children. This burden is relatively well documented in Asia, and this supplement provides new data on the substantial burden in several sub-Saharan African countries. Challenges in standardized surveillance and imperfect diagnostic tools have resulted in patchy local disease data, which are not well acknowledged or integrated into local country evidence and health awareness for decision making. There is a need to strengthen diagnostics for the generation of burden data in country. Furthermore, the guidelines and training for treatment of enteric fever cases in Africa are sorely needed to help mitigate the inappropriate use of antimicrobial treatment. Classic water safety and access to sanitation development remain powerful tools for the control of typhoid fever, yet the huge economic costs and long timelines are unlikely to provide a short- to middle-term solution. Emerging threats, including multidrug resistance and increasing urbanization in regions such as sub-Saharan Africa, warrant focused attention to shorter-term interventions including immunization, and must include vaccine strategies with the new typhoid conjugate vaccines. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.

Salmonella serotypeTyphi, Shigella, and intestinal parasites among food handlers at Bahir Dar University, Ethiopia.

Science.gov (United States)

Abera, Bayeh; Yitayew, Gashaw; Amare, Hiwot

2016-02-28

Food handlers play a major role in the transmission of Salmonella serotype Typhi (S. Typhi), Shigella, and intestinal parasites. This study was conducted to determine the prevalence of S. Typhi, Shigella, and intestinal parasites among food handlers at Bahir Dar University, Ethiopia. A cross-sectional study was conducted in June 2014. Stool samples from 410 food handlers were examined for bacterial pathogens and parasites. Pearson's Chi-square test, Fisher's exact test, and bivariate and multivariate logistic regression analyses were used where appropriate. The prevalence of S. Typhi, Shigella, and intestinal parasites among food handlers was 11 (2.7%), 5 (1.2%), and 53 (12.9%), respectively. Among eight intestinal parasites identified, the two most prevalent intestinal parasites were hookworm 26 (6.3%) and G. lamblia 13 (3.1%). Male food handlers were more likely to be positive than were female food handlers for S. Typhi and intestinal parasites. Furthermore, food handlers who had a history of regular medical checkups were less infected with intestinal parasites. Being male (AOR: 2.1, 95% CI: 1.2, 4.4) and not attending medical checkups (AOR: 2.9, 95% CI: 1.4, 6.1) were independent predictors of intestinal parasitic infection in food handlers. Male food handlers were reluctant to have regular parasitological examinations. There was a high proportion of food handlers with S. Typhi, Shigella, and intestinal parasites in their faces. Special emphasis should be placed on S. Typhicarriers and male food handlers. Education and periodical medical checkups for intestinal parasites and S. Typhi should be considered as intervention measures.

Salmonella enterica: Survival, Colonization, and Virulence Differences among Serovars

Science.gov (United States)

Andino, A.; Hanning, I.

2015-01-01

Data indicate that prevalence of specific serovars of Salmonella enterica in human foodborne illness is not correlated with their prevalence in feed. Given that feed is a suboptimal environment for S. enterica, it appears that survival in poultry feed may be an independent factor unrelated to virulence of specific serovars of Salmonella. Additionally, S. enterica serovars appear to have different host specificity and the ability to cause disease in those hosts is also serovar dependent. These differences among the serovars may be related to gene presence or absence and expression levels of those genes. With a better understanding of serovar specificity, mitigation methods can be implemented to control Salmonella at preharvest and postharvest levels. PMID:25664339

Salmonella enterica: Survival, Colonization, and Virulence Differences among Serovars

Directory of Open Access Journals (Sweden)

A. Andino

2015-01-01

Full Text Available Data indicate that prevalence of specific serovars of Salmonella enterica in human foodborne illness is not correlated with their prevalence in feed. Given that feed is a suboptimal environment for S. enterica, it appears that survival in poultry feed may be an independent factor unrelated to virulence of specific serovars of Salmonella. Additionally, S. enterica serovars appear to have different host specificity and the ability to cause disease in those hosts is also serovar dependent. These differences among the serovars may be related to gene presence or absence and expression levels of those genes. With a better understanding of serovar specificity, mitigation methods can be implemented to control Salmonella at preharvest and postharvest levels.

High-throughput bacterial SNP typing identifies distinct clusters of Salmonella Typhi causing typhoid in Nepalese children

LENUS (Irish Health Repository)

Holt, Kathryn E

2010-05-31

Abstract Background Salmonella Typhi (S. Typhi) causes typhoid fever, which remains an important public health issue in many developing countries. Kathmandu, the capital of Nepal, is an area of high incidence and the pediatric population appears to be at high risk of exposure and infection. Methods We recently defined the population structure of S. Typhi, using new sequencing technologies to identify nearly 2,000 single nucleotide polymorphisms (SNPs) that can be used as unequivocal phylogenetic markers. Here we have used the GoldenGate (Illumina) platform to simultaneously type 1,500 of these SNPs in 62 S. Typhi isolates causing severe typhoid in children admitted to Patan Hospital in Kathmandu. Results Eight distinct S. Typhi haplotypes were identified during the 20-month study period, with 68% of isolates belonging to a subclone of the previously defined H58 S. Typhi. This subclone was closely associated with resistance to nalidixic acid, with all isolates from this group demonstrating a resistant phenotype and harbouring the same resistance-associated SNP in GyrA (Phe83). A secondary clone, comprising 19% of isolates, was observed only during the second half of the study. Conclusions Our data demonstrate the utility of SNP typing for monitoring bacterial populations over a defined period in a single endemic setting. We provide evidence for genotype introduction and define a nalidixic acid resistant subclone of S. Typhi, which appears to be the dominant cause of severe pediatric typhoid in Kathmandu during the study period.

OPTIMATION OF 48 KHZ ULTRASONIC WAVE DOSE FOR THE INACTIVATION OF SALMONELLA TYPHI

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Dwi May Lestari

2015-01-01

Full Text Available This study was aimed to determine the effect of ultrasonic dose exposure which could decrease the viability of Salmonella typhi by using the variation of exposure time (15, 20, 25, and 30 minutes and volume of bacterial suspension (2, 4, 6, and 8 ml at constant power. The sample used was Salmonella typhi. Ultrasonic wave transmitter was a piezoelectric tweeter with 0,191 watts of power and 48 kHz frequency generated by the signal generator. Piezoelectric tweeter was a kind of transducer which converted electrical energy into ultrasonic energy. This research was an experimental laboratory with a completely randomized design. The decrease of bacterial percentage was calculated by using TPC (Total Plate Count. Data were analyzed by using One Way Anova. The results showed that the variation of exposure time and volume of bacterial suspension gave significant effect on the percentage of Salmonella typhi kill. The most optimal of ultrasonic dose exposure to kill Salmonella typhi was 281.87 J/ml with 100% bacterial kill.

Salmonella typhi time to change empiric treatment

DEFF Research Database (Denmark)

Gade, C.; Engberg, J.; Weis, N.

2008-01-01

In the present case series report we describe seven recent cases of typhoid fever. All the patients were travellers returning from Pakistan, where typhoid is endemic. Salmonella typhi isolated from the patients by blood culture were reported as intermediary susceptible to fluoroquinolones in six...

Septic arthritis of the hip in a Cambodian child caused by multidrug-resistant Salmonella enterica serovar Typhi with intermediate susceptibility to ciprofloxacin treated with ceftriaxone and azithromycin.

Science.gov (United States)

Pocock, J M; Khun, P A; Moore, C E; Vuthy, S; Stoesser, N; Parry, C M

2014-08-01

Septic arthritis is a rare complication of typhoid fever. A 12-year-old boy without pre-existing disease attended a paediatric hospital in Cambodia with fever and left hip pain. A hip synovial fluid aspirate grew multidrug-resistant Salmonella enterica ser. Typhi with intermediate susceptibility to ciprofloxacin. Arthrotomy, 2 weeks of intravenous ceftriaxone and 4 weeks of oral azithromycin led to resolution of symptoms. The optimum management of septic arthritis in drug-resistant typhoid is undefined.

[Formation and persistence of L-variants of Salmonella typhi in experimental typhoid and in carriers].

Science.gov (United States)

Levina, G A; Prozorovskiĭ, S V; Iagud, S L; Grumman, M I; Gorelov, A L

1981-07-01

The possibility of the induction and persistence of S. typhi L-forms in the process of experimental typhoid infection and carriership has been studied in rabbits. This study has revealed that the process of L-transformation leading to the appearance of the imbalanced growth forms and unstable L-forms of S. typhi in the organism of the animals infected with S. typhi culture may occur under the conditions of carriership. Such changed forms can be detected in the organism of the animals 18 months after the primary infection.

Revised Ciprofloxacin Breakpoints for Salmonella: Is it Time to Write an Obituary?

Science.gov (United States)

Girish, Revathy; Kumar, Anil; Khan, Sadia; Dinesh, Kavitha R; Karim, Shamsul

2013-11-01

To determine the minimum inhibitory concentration of ciprofloxacin among 50 blood stream isolates of Salmonella enterica. A total of 50 consecutive isolates of Salmonella enterica were tested for susceptibility to antimicrobials using the Kirby Bauer disk diffusion method. Minimum inhibitory concentrations were determined using Hi-Comb strips. All results were interpreted according to the CLSI guidelines. Of the 50 isolates 70%were Salmonella Typhi, 4% Salmonella paratyphi A, 2% Salmonella paratyphi B and the remaining 10% were identified only as Salmonella species. Using the CLSI 2011 breakpoints for disc diffusion, 86% (43/50) were resistant to nalidixic acid(NA), 22% (11/50) to ciprofloxacin, 12% to azithromycin, 6% to cotrimoxazole, 4% to ampicillin and 1% to chloramphenicol. The MIC50 and MIC90 of ciprofloxacin for S.Typhi were 0.181 μg/mL and 5.06 μg/mL respectively. While the same for S. paratyphi A was 0.212μg/mL and 0.228μg/mL respectively. None of the isolates were multi drug resistant and all were susceptible to ceftriaxone. Using the CLSI 2012 revised ciprofloxacin breakpoints for disc diffusion (>31mm) & MIC (<0.06 μg/mL), 90% (45/50) of these isolates were found to be resistant. MIC's of ciprofloxacin should be reported for all salmonella isolates and should be used to guide treatment. Blindly following western guidelines for a disease which is highly endemic in the subcontinent will spell the death knell of a cheap and effective drug in our armamentarium. Therefore it will be too premature to declare that "the concept of using ciprofloxacin in typhoid fever is dead!"

Early diagnosis of typhoid by pcr for flic-d gene of salmonella typhi in patients taking antibiotics

International Nuclear Information System (INIS)

Munir, T.; Razak, S.

2015-01-01

To compare PCR (Polymerase Chain Reaction) with blood culture, typhi-dot and Widal test for the diagnosis of typhoid in patients taking antibiotics. Study Design: Cross-sectional, comparative study. Place and Duration of Study: National University of Sciences and Technology, Islamabad, Pakistan, from April 2013 to August 2014. Methodology: One hundred and five patients were included in the study. Blood was collected and inoculated into tryptone soya broth for culture. Any growth obtained was identified by API 20 E and confirmed by Salmonellaanti-sera. Typhi-dot and Widal test were also done on all the samples. DNA extraction was done and PCR was carried out. Results: Among the 105 patients, 79 (75.2%) were males and 26 (24.8%) were females, with mean age of 20.64 ± 4 years. Typhi-dot was positive in 58 (55.2%) and negative in 47 (44.8%) patients. Blood widal test was positive in 27 (25.7%) and negative in 78 (74.3%) patients. Salmonella Typhi was positive on blood culture in only one (1%) patient. PCR for Salmonella Typhi was positive in 102 (97.1%) and negative in 3 (2.9%) patients. Positive cases detected by PCR were significantly higher as compared to Typhi-dot (p < 0.001), blood Widal test (p < 0.001) and blood culture (p < 0.001). Conclusion: Positivity rate of PCR was significantly higher as compared to blood culture, Typhi-dot or Widal test for diagnosing typhoid in patients who were already taking antibiotics. (author)

Listeria monocytogenes serovar 4a is a possible evolutionary intermediate between L. monocytogenes serovars 1/2a and 4b and L. innocua.

Science.gov (United States)

Chen, Jianshun; Jiang, Lingli; Chen, Xueyan; Luo, Xiaokai; Chen, Yang; Yu, Ying; Tian, Guoming; Liu, Dongyou; Fang, Weihuan

2009-03-01

The genus Listeria consists of six closely related species and forms three phylogenetic groups: L. monocytogenes- L. innocua, L. ivanovii-L. seeligeri-L. welshimeri, and L. grayi. In this report, we attempted to examine the evolutionary relationship in the L. monocytogenes-L. innocua group by probing the nucleotide sequences of 23S rRNA and 16S rRNA, and the gene clusters lmo0029-lmo0042, ascBdapE, rplS-infC, and prs-ldh in L. monocytogenes serovars 1/2a, 4a, and 4b, and L. innocua. Additionally, we assessed the status of L. monocytogenes-specific inlA and inlB genes and 10 L. innocua-specific genes in these species/serovars, together with phenotypic characterization by using in vivo and in vitro procedures. The results indicate that L. monocytogenes serovar 4a strains are genetically similar to L. innocua in the lmo0035-lmo0042, ascB-dapE, and rplS-infC regions and also possess L. innocua-specific genes lin0372 and lin1073. Furthermore, both L. monocytogenes serovar 4a and L. innocua exhibit impaired intercellular spread ability and negligible pathogenicity in mouse model. On the other hand, despite resembling L. monocytogenes serovars 1/2a and 4b in having a nearly identical virulence gene cluster, and inlA and inlB genes, these serovar 4a strains differ from serovars 1/2a and 4b by harboring notably altered actA and plcB genes, displaying strong phospholipase activity and subdued in vivo and in vitro virulence. Thus, by possessing many genes common to L. monocytogenes serovars 1/2a and 4b, and sharing many similar gene deletions with L. innocua, L. monocytogenes serovar 4a represents a possible evolutionary intermediate between L. monocytogenes serovars 1/2a and 4b and L. innocua.

Serovars of Mycobacterium avium Complex isolated from patients in Denmark

DEFF Research Database (Denmark)

Askgaard, D. S.; Giese, Steen Bjørck; Thybo, S.

1994-01-01

Danish isolates of Mycobacterium avium complex were serotyped by the use of seroagglutination. The most prevalent serovars among patients with AIDS (n = 89) were 4 and 6, while among non-AIDS patients the most prevalent serovars were 1, 6, and 4, with no major differences between those in patients...... with pulmonary disease (n = 65) and those in patients with lymph node infection (n = 58). The results suggest a Scandinavian distribution of serovars with a predominance of serovar 6 and fail to demonstrate any selective protection against different serovars by Mycobacterium bovis ECG vaccination....

Diagnosis of acute and chronic enteric fever using metabolomics

OpenAIRE

Näsström, Elin

2017-01-01

Enteric (or typhoid) fever is a systemic infection mainly caused by Salmonella Typhi and Salmonella Paratyphi A. The disease is common in areas with poor water quality and insufficient sanitation. Humans are the only reservoir for transmission of the disease. The presence of asymptomatic chronic carriers is a complicating factor for the transmission. There are major limitations regarding the current diagnostic methods both for acute infection and chronic carriage. Metabolomics is a methodolog...

Salmonella Typhi-specific multifunctional CD8+ T cells play a dominant role in protection from typhoid fever in humans.

Science.gov (United States)

Fresnay, Stephanie; McArthur, Monica A; Magder, Laurence; Darton, Thomas C; Jones, Claire; Waddington, Claire S; Blohmke, Christoph J; Angus, Brian; Levine, Myron M; Pollard, Andrew J; Sztein, Marcelo B

2016-03-01

Typhoid fever, caused by the human-restricted organism Salmonella Typhi (S. Typhi), is a major public health problem worldwide. Development of novel vaccines remains imperative, but is hampered by an incomplete understanding of the immune responses that correlate with protection. Recently, a controlled human infection model was re-established in which volunteers received ~10(3) cfu wild-type S. Typhi (Quailes strain) orally. Twenty-one volunteers were evaluated for their cell-mediated immune (CMI) responses. Ex vivo PBMC isolated before and up to 1 year after challenge were exposed to three S. Typhi-infected targets, i.e., autologous B lymphoblastoid cell-lines (B-LCL), autologous blasts and HLA-E restricted AEH B-LCL cells. CMI responses were evaluated using 14-color multiparametric flow cytometry to detect simultaneously five intracellular cytokines/chemokines (i.e., IL-17A, IL-2, IFN-g, TNF-a and MIP-1b) and a marker of degranulation/cytotoxic activity (CD107a). Herein we provide the first evidence that S. Typhi-specific CD8+ responses correlate with clinical outcome in humans challenged with wild-type S. Typhi. Higher multifunctional S. Typhi-specific CD8+ baseline responses were associated with protection against typhoid and delayed disease onset. Moreover, following challenge, development of typhoid fever was accompanied by decreases in circulating S. Typhi-specific CD8+ T effector/memory (TEM) with gut homing potential, suggesting migration to the site(s) of infection. In contrast, protection against disease was associated with low or no changes in circulating S. Typhi-specific TEM. These studies provide novel insights into the protective immune responses against typhoid disease that will aid in selection and development of new vaccine candidates.

Typhoid toxin provides a window into typhoid fever and the biology of Salmonella Typhi.

Science.gov (United States)

Galán, Jorge E

2016-06-07

Salmonella Typhi is the cause of typhoid fever, a disease that has challenged humans throughout history and continues to be a major public health concern. Unlike infections with most other Salmonellae, which result in self-limiting gastroenteritis, typhoid fever is a life-threatening systemic disease. Furthermore, in contrast to most Salmonellae, which can infect a broad range of hosts, S. Typhi is a strict human pathogen. The unique features of S. Typhi pathogenesis and its stringent host specificity have been a long-standing puzzle. The discovery of typhoid toxin not only has provided major insight into these questions but also has offered unique opportunities to develop novel therapeutic and prevention strategies to combat typhoid fever.

Oral Challenge with Wild-Type Salmonella Typhi Induces Distinct Changes in B Cell Subsets in Individuals Who Develop Typhoid Disease.

OpenAIRE

Franklin R Toapanta; Paula J Bernal; Stephanie Fresnay; Laurence S Magder; Thomas C Darton; Claire Jones; Claire S Waddington; Christoph J Blohmke; Brian Angus; Myron M Levine; Andrew J Pollard; Marcelo B Sztein

2016-01-01

A novel human oral challenge model with wild-type Salmonella Typhi (S. Typhi) was recently established by the Oxford Vaccine Group. In this model, 104 CFU of Salmonella resulted in 65% of participants developing typhoid fever (referred here as typhoid diagnosis -TD-) 6?9 days post-challenge. TD was diagnosed in participants meeting clinical (oral temperature ?38?C for ?12h) and/or microbiological (S. Typhi bacteremia) endpoints. Changes in B cell subpopulations following S. Typhi challenge re...

In vivo expression of Salmonella enterica serotype Typhi genes in the blood of patients with typhoid fever in Bangladesh.

Directory of Open Access Journals (Sweden)

Alaullah Sheikh

2011-12-01

Full Text Available Salmonella enterica serotype Typhi is the cause of typhoid fever. It is a human-restricted pathogen, and few data exist on S. Typhi gene expression in humans.We applied an RNA capture and amplification technique, Selective Capture of Transcribed Sequences (SCOTS, and microarray hybridization to identify S. Typhi transcripts expressed in the blood of five humans infected with S. Typhi in Bangladesh. In total, we detected the expression of mRNAs for 2,046 S. Typhi genes (44% of the S. Typhi genome in human blood; expression of 912 genes was detected in all 5 patients, and expression of 1,100 genes was detected in 4 or more patients. Identified transcripts were associated with the virulence-associated PhoP regulon, Salmonella pathogenicity islands, the use of alternative carbon and energy sources, synthesis and transport of iron, thiamine, and biotin, and resistance to antimicrobial peptides and oxidative stress. The most highly represented group were genes currently annotated as encoding proteins designated as hypothetical, unknown, or unclassified. Of the 2,046 detected transcripts, 1,320 (29% of the S. Typhi genome had significantly different levels of detection in human blood compared to in vitro cultures; detection of 141 transcripts was significantly different in all 5 patients, and detection of 331 transcripts varied in at least 4 patients. These mRNAs encode proteins of unknown function, those involved in energy metabolism, transport and binding, cell envelope, cellular processes, and pathogenesis. We confirmed increased expression of a subset of identified mRNAs by quantitative-PCR.We report the first characterization of bacterial transcriptional profiles in the blood of patients with typhoid fever. S. Typhi is an important global pathogen whose restricted host range has greatly inhibited laboratory studies. Our results suggest that S. Typhi uses a largely uncharacterized genetic repertoire to survive within cells and utilize alternate

Enteric fever in the Pacific: a regional retrospective study from Auckland, New Zealand.

Science.gov (United States)

Lane, R J; Holland, D; McBride, S; Perera, S; Zeng, I; Wilson, M; Read, K; Jelleyman, T; Ingram, R J H

2015-02-01

There are limited clinical data on enteric fever in the Pacific and New Zealand (NZ) compared with the Indian subcontinent (ISC) and South-East Asia (SEA). Our objective was to describe enteric fever in Auckland - a large Pacific city, focusing on disease acquired in these regions. We reviewed enteric fever cases hospitalised in Auckland from January 2005 to December 2010. Microbiologically confirmed EF was identified in 162 patients. Travel regions: Pacific, 40 cases (25%) (Samoa, 38; Fiji, two), ISC, 72 (44%), SEA, seven (4%), other, three (2%), no travel, 40 (25%). Enteric fever rates for Auckland resident travellers were: India 50.3/100 000; Samoa 19.7/100 000.All Pacific cases were Salmonella Typhi. Of local isolates (without travel history), 38 were S. Typhi (36 fully susceptible, one multi-drug resistant (MDR) + nalidixic acid resistant (NAR), one unknown) and two S. Paratyphi (both NAR). Of non-Pacific travel, 56/82 (69%) isolates were S. Typhi, the remainder S. Paratyphi (15 isolates were fully susceptible, only 1% were MDR). Significant associations of serotype and antibiotic resistance with different travel regions and similarity of phage types (local and Pacific) were observed. Headache, vomiting and acute kidney injuries were more frequent with Pacific travel, while abdominal distension and cholecystitis with local disease. Shorter duration of treatment in the Pacific group was seen despite length of stay in hospital not being reduced. Local cases were associated with longer hospital admissions. One half of cases in Auckland are acquired either from Pacific or locally. Similarities mean that disease acquired locally is likely of Pacific origin. © 2014 Royal Australasian College of Physicians.

An evaluation of purified Salmonella Typhi protein antigens for the serological diagnosis of acute typhoid fever

NARCIS (Netherlands)

Tran Vu Thieu, Nga; Trinh van, Tan; Tran Tuan, Anh; Klemm, Elizabeth J.; Nguyen Ngoc Minh, Chau; Voong Vinh, Phat; Pham Thanh, Duy; Ho Ngoc Dan, Thanh; Pham Duc, Trung; Langat, Pinky; Martin, Laura B.; Galan, Jorge; Liang, Li; Felgner, Philip L.; Davies, D. Huw; de Jong, Hanna K.; Maude, Rapeephan R.; Fukushima, Masako; Wijedoru, Lalith; Ghose, Aniruddha; Samad, Rasheda; Dondorp, Arjen M.; Faiz, Abul; Darton, Thomas C.; Pollard, Andrew J.; Thwaites, Guy E.; Dougan, Gordon; Parry, Christopher M.; Baker, Stephen

2017-01-01

The diagnosis of typhoid fever is a challenge. Aiming to develop a typhoid diagnostic we measured antibody responses against Salmonella Typhi (S. Typhi) protein antigens and the Vi polysaccharide in a cohort of Bangladeshi febrile patients. IgM against 12 purified antigens and the Vi polysaccharide

Comparative evaluation of two rapid Salmonella-IgM tests and blood culture in the diagnosis of enteric fever.

Science.gov (United States)

Prasad, K J; Oberoi, J K; Goel, N; Wattal, C

2015-01-01

Enteric fever is a major public health problem in developing countries like India. An early and accurate diagnosis is necessary for a prompt and effective treatment. We have evaluated the diagnostic accuracy of two Rapid Salmonella-IgM tests (Typhidot-IgM and Enteroscreen-IgM) as compared to blood culture in rapid and early diagnosis of enteric fever. A total of 2,699 patients' serum samples were tested by Rapid Salmonella-IgM tests and blood culture. Patients were divided into two groups. Test group - patients with enteric fever and blood culture positives for Salmonella Typhi; and three types of Controls, i.e. patients with non-enteric fever illnesses, normal healthy controls and patients positive for S. Paratyphi- A. In addition to this we have also evaluated the significance of positive Salmonella-IgM tests among blood culture-negative cases. The overall sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the Typhidot-IgM test and Enteroscreen-IgM test considering blood culture as gold standard were 97.29% and 88.13%, 97.40% and 87.83%, 98.18% and 92.03%, 96.15% and 82.27%, respectively. Typhidot-IgM test was found to be significantly more sensitive and specific as compared to Enteroscreen-IgM. Among blood culture-negative patients, Rapid Salmonella-IgM tests detected 72.25% additional cases of enteric fever. Although the Rapid Salmonella-IgM tests are meant to diagnose S. Typhi only, but these tests detect S. Paratyphi- A also. Thirty-eight patients who were blood culture-positive for S. Paratyphi- A were also positive by Rapid Salmonella-IgM tests. Rapid Salmonella-IgM tests offer an advantage of increased sensitivity, rapidity, early diagnosis and simplicity over blood culture.

Direct evidence of Rickettsia typhi infection in Rhipicephalus ...

African Journals Online (AJOL)

These studies remarks that in addition to rats, other animals like cats, opossums and dogs could be implied in the transmission of Rickettsia typhi as infected fleas obtained from serologically positive animals have been detected in samples from endemic areas. In Mexico, the higher number of murine typhus cases have ...

Serovars of Salmonella from captive reptiles

DEFF Research Database (Denmark)

Pedersen, Karl; Lassen-Nielsen, Anne Marie; Nordentoft, Steen

2009-01-01

The distribution on serovars of 60 Salmonella isolates from reptiles kept in captivity in Denmark during the period 1995–2006 was investigated. The isolates were all recovered from clinical specimens submitted to the National Veterinary Institute. A majority of the samples were from reptiles...... in zoological gardens or similar, while a minor number was from reptiles kept in private homes. A total of 43 serovars were detected, most of them being what is usually called exotic serotypes, and many not having a trivial name, while a few isolates belonged to well-known human pathogenic serovars, such as S....... Enteritidis, S. Typhimurium, S. Bovismorbificans. One isolate was rough and two were non-typeable. Isolates from turtles belonged to the subspecies enterica, while many isolates from both sauria and snakes belonged to other subspecies. The findings underline the potential zoonotic risk by handling reptiles...

Camel as a transboundary vector for emerging exotic Salmonella serovars.

Science.gov (United States)

Ghoneim, Nahed H; Abdel-Moein, Khaled A; Zaher, Hala

2017-05-01

The current study was conducted to shed light on the role of imported camels as a transboundary vector for emerging exotic Salmonella serovars. Fecal samples were collected from 206 camels directly after slaughtering including 25 local camels and 181 imported ones as well as stool specimens were obtained from 50 slaughterhouse workers at the same abattoir. The obtained samples were cultured while Salmonella serovars were identified through Gram's stain films, biochemical tests and serotyping with antisera kit. Moreover, the obtained Salmonella serovars were examined by PCR for the presence of invA and stn genes. The overall prevalence of Salmonella serovars among the examined camels was 8.3%. Stn gene was detected in the vast majority of exotic strains (11/14) 78.6% including emerging serovars such as Salmonella Saintpaul, S. Chester, S. Typhimurium whereas only one isolate from local camels carried stn gene (1/3) 33.3%. On the other hand, none of the examined humans yielded positive result. Our findings highlight the potential role of imported camels as a transboundary vector for exotic emerging Salomenella serovars.

Failure of oral antibiotic therapy, including azithromycin, in the treatment of a recurrent breast abscess caused by Salmonella enterica serotype Paratyphi A.

Science.gov (United States)

Fernando, Shelanah; Molland, Janice Gail; Gottlieb, Thomas

2012-10-01

We report a case of recurrent, multifocal Salmonella enterica serotype Paratyphi A breast abscesses, resistant to ciprofloxacin, which relapsed despite surgery, aspiration and multiple courses of antibiotics, including co-trimoxazole and azithromycin. The patient was cured after a prolonged course of intravenous ceftriaxone.

Antimicrobial susceptibility of Salmonella isolates from healthy pigs and chickens (2008-2011).

Science.gov (United States)

de Jong, Anno; Smet, Annemieke; Ludwig, Carolin; Stephan, Bernd; De Graef, Evelyne; Vanrobaeys, Mia; Haesebrouck, Freddy

2014-07-16

Using the agar dilution method, antimicrobial susceptibility to human-use antibiotics was determined among Belgian faecal Salmonella isolates from healthy pigs and broiler chickens. Both epidemiological cut-off values and clinical breakpoints were applied for interpretation of the results. Cephalosporin-resistant isolates were examined for the presence of genes encoding CTX-M, SHV, TEM and CMY β-lactamases. All isolates with decreased quinolone susceptibility were screened for plasmid-borne genes qnr, qepA and aac(6')-Ib-cr. In all, 368 Salmonella isolates were recovered from pigs and 452 from chickens. Clinical resistance to ciprofloxacin was absent in isolates of both host species, and was 1.9 and 13.1% to cefotaxime in pig and poultry isolates, respectively. Decreased susceptibility to cefotaxime amounted to 2.2 and 0.7%, whereas for ciprofloxacin this was 3.0 and 23.0% in pig and poultry isolates, respectively. Ciprofloxacin decreased susceptibility was limited to few serovars, mainly Paratyphi B. Multidrug resistance was markedly higher for pig isolates (39.7%) than for chicken isolates (17.3%). Sixty-six cefotaxime-resistant isolates, 59 from chickens and 7 from pigs, were phenotypically determined as ESBL/AmpC producers; predominantly Paratyphi B and Typhimurium serovars. BlaCTX-M (mostly blaCTXM-1, but also blaCTXM-2 and blaCTXM-9) and blaTEM-52 were the predominant ESBL genes. Only few isolates expressed SHV-12 or an AmpC enzyme (CMY-2). Isolates of four serovars carried qnr genes: Brandenburg and Llandof from pigs, both qnrS; Indiana and Paratyphi B from chickens with qnrB and qnrA. The latter isolate carried blaCTX-M-9 and was the only strain with a plasmid-borne quinolone resistance gene among the ESBL/AmpC producers. This Salmonella survey confirms that the ESBL/AmpC producers are particularly prevalent in chickens (12.8%), and much less in pigs (1.9%). A link between plasmid-borne quinolone resistance genes and ESBLs/AmpC was uncommon. Copyright �

Antimicrobial susceptibility pattern in children with typhoid fever and serotype of Salmonella typhi in Jakarta

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Mirari Prasadajudio, Mulya Rahma Karyanti, Lia Waslia

2017-03-01

Full Text Available Objectives: Indonesia is known for high incidence of typhoid fever especially in children. This study aimed to observe antibiotic susceptibility in circulating Salmonella typhi serotypes in children with typhoid. Methods: A cross sectional study design was conducted. A total of 142 blood samples from children between 1-18 years old clinically diagnosed with suspected typhoid fever were recruited between January 2012 and July 2013 from six health centers in Jakarta. Confirmed cases were retrieved based on S. typhi isolate finding in blood culture. Antimicrobial susceptibility was investigated and PCR was used to detect S. typhi serotypes using fliB, fliC and aroC genes. Results: The prevalence of confirmed typhoid case based on isolate finding was 22 (15.5%. Twenty of S. typhi isolates expressed fliC gene carrying H:d allele, the other two expressed j allele, while only two samples expressed fliB, all showed no difference in pathogenicity and antimicrobial resistance. Conclusions: Circulating serotypes found in typhoid children in Jakarta, Indonesia are still susceptible even to the firstline antimicrobials. Thus, chloramphenicol, ampicillin and co-trimoxazole are still recommended. J Microbiol Infect Dis 2017; 7(1: 29-35

Epidemiologic analysis of sporadic Salmonella typhi isolates and those from outbreaks by pulsed-field gel electrophoresis.

Science.gov (United States)

Thong, K L; Cheong, Y M; Puthucheary, S; Koh, C L; Pang, T

1994-05-01

Pulsed-field gel electrophoresis (PFGE) was used to compare and analyze 158 isolates of Salmonella typhi from five well-defined outbreaks of typhoid fever in Malaysia and also isolates involved in sporadic cases of typhoid fever occurring during the same period. Digestion of chromosomal DNAs from these S. typhi isolates with the restriction endonucleases XbaI (5'-TCTAGA-3'), SpeI (5'-ACTAGT-3'), and AvrII (5'-CCTAGG-3') and then PFGE produced restriction endonuclease analysis (REA) patterns consisting of 11 to 24 DNA fragments ranging in size from 20 to 630 kbp. Analysis of the REA patterns generated by PFGE after digestion with XbaI and SpeI indicated that the S. typhi isolates obtained from sporadic cases of infection were much more heterogeneous (at least 13 different REA patterns were detected; Dice coefficient, between 0.73 and 1.0) than those obtained during outbreaks of typhoid fever. The clonal nature and the close genetic identities of isolates from outbreaks in Alor Setar, Penang, Kota Kinabalu, Johor Bahru, and Kota Bahru were suggested by the fact that only a limited number of REA patterns, which mostly differed by only a single band, were detected (one to four patterns; Dice coefficient, between 0.82 and 1.0), although a different pattern was associated with each of these outbreaks. Comparison of REA patterns with ribotyping for 18 S. typhi isolates involved in sporadic cases of infection showed a good correlation, in that 72% of the isolates were in the same group. There was no clear correlation of phage types with a specific REA pattern. We conclude that PFGE of s. typhi chromosomal DNA digested with infrequently cutting restriction endonucleases is a useful method for comparing and differentiating S. typhi isolates for epidemiological purposes.

Antibacterial activity of some commonly used food commodities against escherichia coli, salmonella typhi and staphylococcus aureus

International Nuclear Information System (INIS)

Siddiqui, A.; Ansari, A.

2009-01-01

The activity of commonly used spices and salt, sugar and pickles against Escherichia coli, Salmonella typhi and staphlococcus aureus was tested. The antibacterial activity was found to be in descending order like coriander>pickles>salt and sugar>clove>black pepper>red chilli against S. typhi and garlic>clove>onion>ginger against S. aureus. (author)

Expression of intra- and extracellular granzymes in patients with typhoid fever

NARCIS (Netherlands)

de Jong, Hanna K.; Garcia-Laorden, Maria Isabel; Hoogendijk, Arie J.; Parry, Christopher M.; Maude, Rapeephan R.; Dondorp, Arjen M.; Faiz, Mohammed Abul; van der Poll, Tom; Wiersinga, Willem Joost

2017-01-01

Background Typhoid fever, caused by the intracellular pathogen Salmonella (S.) enterica serovar Typhi, remains a major cause of morbidity and mortality worldwide. Granzymes are serine proteases promoting cytotoxic lymphocytes mediated eradication of intracellular pathogens via the induction of cell

The influence of MAP condition and active compounds on the radiosensitization of Escherichia coli and Salmonella typhi present in chicken breast

International Nuclear Information System (INIS)

Lacroix, M.; Chiasson, F.

2004-01-01

The efficiency of carvacrol, thymol, trans-cinnamaldehyde (Tc) and tetrasodium pyrophosphate (Tp) on the radiosensitization of Escherichia coli and Salmonella typhi in chicken breast was determined. Chicken breast were dipped in a bath of working cultures of E. coli or S. typhi (5x10 7 CFU/ml). Active compounds were added at the concentration corresponding to ((1)/(30)) of the minimal inhibitory concentration. Samples were packed under air and gamma irradiation was done at doses from 0.1 to 0.7 kGy. The efficiencies of the active compounds against E. coli were 32%, 10%, 3% and 0% for thymol, Tp and carvacrol, respectively. For S. typhi, the efficiencies in the chicken breast were 47%, 19%, 17% and 11% for Tc, Tp, carvacrol and thymol, respectively. Without active compounds, D 10 values were 0.145 kGy for E. coli and 0.64 kGy for S. typhi as compared to 0.098 kGy for E. coli and 0.341 kGy for S. typhi in presence of Tc. Under modified atmospheric packaging condition and in presence of Tc, D 10 values were reduced to 0.046 for E. coli and to 0.110 for S. typhi

First isolation of Salmonella enterica serovar Napoli from wild birds in Italy

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Laura Mancini

2014-03-01

Full Text Available Salmonella enterica serovar Napoli (S. Napoli is an emerging serovar in Italy. It accounts for 2-4% of all serovars isolated from human infections. The zoonotic origin of this serovar is still unknown and this makes difficult to apply any control intervention. We report here the isolation of S. Napoli from a river nightingale (Cettia cetti, Temminck 1820 which represents the first description of this serovar from wild birds. This finding adds knowledge to the ecology of S. Napoli and addresses further studies aimed to assess the epidemiologic link between S. Napoli isolated from wild birds, food, environmental sources and human infections.

Molecular characterization of Salmonella Paratyphi B dT+ and Salmonella Heidelberg from poultry and retail chicken meat in Colombia by pulsed-field gel electrophoresis

Science.gov (United States)

Salmonella Paratyphi B dT+ variant (also termed Salmonella Java) and Salmonella Heidelberg are human pathogens frequently isolated from poultry. As a step towards implementing the Colombian Integrated Program for Antimicrobial Resistant Surveillance (COIPARS), this study characterized molecular patt...

Encephalitis in a traveller with typhoid fever: efficacy of corticosteroids.

Science.gov (United States)

Mellon, Guillaume; Eme, Anne-Line; Rohaut, Benjamin; Brossier, Florence; Epelboin, Loïc; Caumes, Eric

2017-09-01

Typhoid fever is a bacterial infection caused by Salmonella typhi or S. paratyphi, recognized as a classical cause of fever in returning travellers. However, neuropsychiatric presentations are rarely reported in travellers diagnosed in western countries, whereas they are more commonly described in patients treated in endemic areas. We describe such a case and discuss the pathophysiologic mechanisms of this complication. © International Society of Travel Medicine, 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The classification of Sejroe group serovars of Leptospira interrogans with monoclonal antibodies

NARCIS (Netherlands)

Terpstra, W. J.; Korver, H.; van Leeuwen, J.; Klatser, P. R.; Kolk, A. H.

1985-01-01

Using the hybridoma technique we produced monoclonal antibodies to serovars of Leptospira interrogans. We focussed on serovar hardjo which is an important pathogen for humans and animals, and on other serovars of the Sejroe group. With combinations of monoclonals, characteristic patterns of

Inhibition of Salmonella typhi growth using extremely low frequency electromagnetic (ELF-EM) waves at resonance frequency.

Science.gov (United States)

Fadel, M A; Mohamed, S A; Abdelbacki, A M; El-Sharkawy, A H

2014-08-01

Typhoid is a serious disease difficult to be treated with conventional drugs. The aim of this study was to demonstrate a new method for the control of Salmonella typhi growth, through the interference with the bioelectric signals generated from the microbe during cell division by extremely low frequency electromagnetic waves (ELF-EMW-ELF-EM) at resonance frequency. Isolated Salmonella typhi was subjected to square amplitude modulated waves (QAMW) with different modulation frequencies from two generators with constant carrier frequency of 10 MHz, amplitude of 10 Vpp, modulating depth ± 2 Vpp and constant field strength of 200 V m(-1) at 37°C. Both the control and exposed samples were incubated at the same conditions during the experiment. The results showed that there was highly significant inhibition effect for Salm. typhi exposed to 0·8 Hz QAMW for a single exposure for 75 min. Dielectric relaxation, TEM and DNA results indicated highly significant changes in the molecular structure of the DNA and cellular membrane resulting from the exposure to the inhibiting EM waves. It was concluded that finding out the inhibiting resonance frequency of ELF-EM waves that deteriorates Salm. typhi growth will be promising method for the treatment of Salm. typhi infection either in vivo or in vitro. This new non-invasive technique for treatment of bacterial infections is of considerable interest for the use in medical and biotechnological applications. © 2014 The Society for Applied Microbiology.

Prevalence of Salmonella typhi and intestinal parasites among food ...

African Journals Online (AJOL)

Background: Food borne diseases are a global public health problem. Food handlers play a major role for the transmission of food borne diseases. Objectives: This study was aimed at exploring the prevalence of intestinal parasites, S. typhi carrier rate and risk factors among food handlers at Bahir Dar town. Methods: A ...

Gangrene of the limb complicating Salmonella typhi Septicaemia in ...

African Journals Online (AJOL)

We report an unusual case of lower limb gangrene in a pubertal boy following a typical clinical presentation of septicaemia due to Salmonella typhi. After an initial response to presumed appropriate antibiotic and supportive therapy, the patient developed tissue ischaemia in both feet. There were no clinical or laboratory ...

The influence of MAP condition and active compounds on the radiosensitization of Escherichia coli and Salmonella typhi present in chicken breast

Energy Technology Data Exchange (ETDEWEB)

Lacroix, M. E-mail: monique.lacroix@inrs-iaf.uquebec.ca; Chiasson, F

2004-10-01

The efficiency of carvacrol, thymol, trans-cinnamaldehyde (Tc) and tetrasodium pyrophosphate (Tp) on the radiosensitization of Escherichia coli and Salmonella typhi in chicken breast was determined. Chicken breast were dipped in a bath of working cultures of E. coli or S. typhi (5x10{sup 7} CFU/ml). Active compounds were added at the concentration corresponding to ((1)/(30)) of the minimal inhibitory concentration. Samples were packed under air and gamma irradiation was done at doses from 0.1 to 0.7 kGy. The efficiencies of the active compounds against E. coli were 32%, 10%, 3% and 0% for thymol, Tp and carvacrol, respectively. For S. typhi, the efficiencies in the chicken breast were 47%, 19%, 17% and 11% for Tc, Tp, carvacrol and thymol, respectively. Without active compounds, D{sub 10} values were 0.145 kGy for E. coli and 0.64 kGy for S. typhi as compared to 0.098 kGy for E. coli and 0.341 kGy for S. typhi in presence of Tc. Under modified atmospheric packaging condition and in presence of Tc, D{sub 10} values were reduced to 0.046 for E. coli and to 0.110 for S. typhi.

Antimicrobial susceptibility profile, treatment outcome and serotype distribution of clinical isolates of Salmonella enterica subspecies enterica: a 2-year study from Kerala, South India

Directory of Open Access Journals (Sweden)

Harichandran D

2017-03-01

Full Text Available Deepa Harichandran, Kavitha Radhakrishnan Dinesh Department of Microbiology, Amrita School of Medicine, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham University, Kochi, Kerala, India Background/purpose: Typhoid and paratyphoid fever continue to be important causes of illness and death in parts of Asia, being associated with poor sanitation and consumption of unsafe food and water. Antimicrobial resistance has emerged to traditional first-line drugs, namely, the fluoroquinolones, as well as to third-generation cephalosporins, posing challenges to treatment. Azithromycin has proven to be an effective alternative for treatment of uncomplicated typhoid fever. The purpose of this study was to determine the antimicrobial susceptibility, clinical outcome and serotype distribution pattern of clinical isolates belonging to Salmonella enterica subspecies enterica. Methodology: All clinical isolates of S. enterica obtained from blood, sterile body fluids, as well as stool and urine samples at Amrita Institute of Medical Sciences and Research Centre, Kerala, India, between August 2011 and July 2013 were included in the study and processed based on standard microbiology protocols. Results: A total of 118 isolates of Salmonella were obtained during the study period. Out of these, 79 were of S. Typhi (66.95%, followed by isolates of S. Paratyphi A (22; 18.64% and S. Typhimurium 12 (10.17%. Five isolates could not be identified further. There was 100% susceptibility to ceftriaxone in all S. enterica subspecies. Ciprofloxacin susceptibility was 32.91% for S. Typhi and 40.90% for S. Paratyphi A as determined by the disk diffusion method. The susceptibility profile of S. Typhi isolates to different antimicrobials was as follows: chloramphenicol (94.93%, ampicillin (77.21%, cotrimoxazole (75.94% and azithromycin (78.48%. For S. Typhi, the minimum inhibitory concentration (MIC of ciprofloxacin required to inhibit the growth

High-resolution melt-curve analysis of random amplified polymorphic DNA (RAPD-HRM) for the characterisation of pathogenic leptospires: intra-serovar divergence, inter-serovar convergence, and evidence of attenuation in Leptospira reference collections.

Science.gov (United States)

Tulsiani, S M; Craig, S B; Graham, G C; Cobbold, R C; Dohnt, M F; Burns, M-A; Jansen, C C; Leung, L K-P; Field, H E; Smythe, L D

2010-07-01

High-resolution melt-curve analysis of random amplified polymorphic DNA (RAPD-HRM) is a novel technology that has emerged as a possible method to characterise leptospires to serovar level. RAPD-HRM has recently been used to measure intra-serovar convergence between strains of the same serovar as well as inter-serovar divergence between strains of different serovars. The results indicate that intra-serovar heterogeneity and inter-serovar homogeneity may limit the application of RAPD-HRM in routine diagnostics. They also indicate that genetic attenuation of aged, high-passage-number isolates could undermine the use of RAPD-HRM or any other molecular technology. Such genetic attenuation may account for a general decrease seen in titres of rabbit hyperimmune antibodies over time. Before RAPD-HRM can be further advanced as a routine diagnostic tool, strains more representative of the wild-type serovars of a given region need to be identified. Further, RAPD-HRM analysis of reference strains indicates that the routine renewal of reference collections, with new isolates, may be needed to maintain the genetic integrity of the collections.

Comparative genomics of pathogenic Leptospira interrogans serovar Canicola isolated from swine and human in Brazil

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Luisa Z Moreno

Full Text Available Leptospira interrogans serovar Canicola is one of the most important pathogenic serovars for the maintenance of urban leptospirosis. Even though it is considered highly adapted to dogs, serovar Canicola infection has already been described in other animals and even a few human cases. Here, we present the genomic characterisation of two Brazilian L. interrogans serovar Canicola strains isolated from slaughtered sows (L0-3 and L0-4 and their comparison with human strain Fiocruz LV133. It was observed that the porcine serovar Canicola strains present the genetic machinery to cause human infection and, therefore, represent a higher risk to public health. Both human and porcine serovar Canicola isolates also presented sequences with high identity to the Chinese serovar Canicola published plasmids pGui1 and pGui2. The plasmids identification in the Brazilian and Chinese serovar Canicola strains suggest that extra-chromosomal elements are one more feature of this serovar that was previously unnoticed.

The emergence and outbreak of multidrug-resistant typhoid fever in China.

Science.gov (United States)

Yan, Meiying; Li, Xinlan; Liao, Qiaohong; Li, Fang; Zhang, Jing; Kan, Biao

2016-06-22

Typhoid fever remains a severe public health problem in developing countries. The emergence of resistant typhoid, particularly multidrug-resistant typhoid infections, highlights the necessity of monitoring the resistance characteristics of this invasive pathogen. In this study, we report a typhoid fever outbreak caused by multidrug-resistant Salmonella enterica serovar Typhi strains with an ACSSxtT pattern. Resistance genes conferring these phenotypes were harbored by a large conjugative plasmid, which increases the threat of Salmonella Typhi and thus requires close surveillance for dissemination of strains containing such genes.

Oral Wild-Type Salmonella Typhi Challenge Induces Activation of Circulating Monocytes and Dendritic Cells in Individuals Who Develop Typhoid Disease

OpenAIRE

Toapanta, Franklin R.; Bernal, Paula J.; Fresnay, Stephanie; Darton, Thomas C.; Jones, Claire; Waddington, Claire S.; Blohmke, Christoph J.; Dougan, Gordon; Angus, Brian; Levine, Myron M.; Pollard, Andrew J.; Sztein, Marcelo B.

2015-01-01

A new human oral challenge model with wild-type Salmonella Typhi (S. Typhi) was recently developed. In this model, ingestion of 104 CFU of Salmonella resulted in 65% of subjects developing typhoid fever (referred here as typhoid diagnosis -TD-) 5-10 days post-challenge. TD criteria included meeting clinical (oral temperature ≥38°C for ≥12 h) and/or microbiological (S. Typhi bacteremia) endpoints. One of the first lines of defense against pathogens are the cells of the innate immune system (e....

Arginine-dependent acid resistance in Salmonella enterica serovar Typhimurium

NARCIS (Netherlands)

Kieboom, J.; Abee, T.

2006-01-01

Salmonella enterica serovar Typhimurium does not survive a pH 2.5 acid challenge under conditions similar to those used for Escherichia coli (J. W. Foster, Nat. Rev. Microbiol. 2:898-907, 2004). Here, we provide evidence that S. enterica serovar Typhimurium can display arginine-dependent acid

Salmonella Typhimurium undergoes distinct genetic adaption during chronic infections of mice

DEFF Research Database (Denmark)

Søndberg, Emilie; Jelsbak, Lotte

2016-01-01

Background Typhoid fever caused by Salmonella enterica serovar Typhi (S. Typhi) is a severe systemic human disease and endemic in regions of the world with poor drinking water quality and sewage treatment facilities. A significant number of patients become asymptomatic life-long carriers of S....... Typhi and serve as the reservoir for the disease. The specific mechanisms and adaptive strategies enabling S. Typhi to survive inside the host for extended periods are incompletely understood. Yet, elucidation of these processes is of major importance for improvement of therapeutic strategies...... been transmitted to the other two mice. Re-infection with this clone confirmed that it is superior to the wild type for intestinal colonisation. Conclusions During 4 to 6 weeks of chronic infections, S. Typhimurium acquired distinct SNPs in known regulators of metabolic and virulence genes. One SNP...

Antimicrobial Effects of Psidium Guajava Extract as One Mechanism of its Antidiarrhoeal Action

Science.gov (United States)

Lutterodt, G.D.; Ismail, A.; Basheer, R.H.; Baharudin, H. Mohd.

1999-01-01

A morphine-like spasmolytic action (not naloxone reversible; involving the inhibition of acetylcholine release) and also effects on the transmural transport of electrolytes (Na+ and K+) and water have been reported as possible modes of the antidiarrhoeal action of polar fractions of Psidium guajava leaf extractives. The objective for this study was to verify if the reported modes of the antidiarrhoeal action should be broadened to include direct antimicrobial actions on some of the more common bacteria known to cause toxin-induced acute diarrhoea. Serial dilutions of a water-soluble, freeze-dried methanolic extract were tested on 10 such organisms, grown separately on nutrient agar plates, to determine the minimum inhibitory concentration (MIC) for each of these bacteria. These included the causative agents for (i) enteric fever (Salmonella typhi, Salmonella paratyphi A, Salmonella paratyphi B and Salmonella paratyphi C), (ii) food poisoning (Salmonella typhimurium and Staphylococcus aureus), (iii) dysentery (Shigella dysenteriae, Shigella flexneri and Shigella sonnei), and (iv) cholera (Vibrio cholerae). The growth of all these organisms was inhibited at the MIC of 10mg/ml of the extract, which is equivalent to 2.5μg/ml of active extractable flavonoids. The most sensitive organisms (MIC = 1mg/ml) were Staphylococcus aureus, Vibrio cholerae and Shigella flexneri. PMID:22589684

Arbitrarily primed PCR- A rapid and simple method for typing of leptospiral serovars

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Ramadass P

2002-01-01

Full Text Available PURPOSE: To investigate the use of arbitrarily primed polymerase chain reaction (AP-PCR for typing of leptospiral serovars. METHODS: AP-PCR was adopted for identification of laboratory strains of leptospires and leptospiral cultures at serovar level. A primer of 12 bp was used for amplifying DNA of 13 laboratory strains of leptospires as well as culture pellets of leptospires. RESULTS: Each serovar produced distinct DNA fingerprint which was characteristic for each serovar. These patterns were used for typing of 81 serum culture samples obtained from human leptospiral cases. Of these samples, 39 could be typed based on AP-PCR fingerprints belonging to serovars autumnalis, pomona, canicola, javanica, icterohaemorrhagiae, patoc and pyrogenes. These results were confirmed by RAPD fingerprinting of the DNA samples of the respective leptospiral serovars after culturing -FNx01them in EMJH media. One of the important findings of this work was that straight culture sample could be used for AP-PCR assay, without purification of DNA. By having more number of AP-PCR reference fingerprints, more serovars could be typed. CONCLUSIONS: AP-PCR technique provides great potential for simple and rapid identification of leptospires at serovar level, which could be useful in molecular epidemiological studies of leptospirosis.

Proteome analysis of serovars Typhimurium and Pullorum of Salmonella enterica subspecies I

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Begum Shajna

2005-07-01

Full Text Available Abstract Background Salmonella enterica subspecies I includes several closely related serovars which differ in host ranges and ability to cause disease. The basis for the diversity in host range and pathogenic potential of the serovars is not well understood, and it is not known how host-restricted variants appeared and what factors were lost or acquired during adaptations to a specific environment. Differences apparent from the genomic data do not necessarily correspond to functional proteins and more importantly differential regulation of otherwise identical gene content may play a role in the diverse phenotypes of the serovars of Salmonella. Results In this study a comparative analysis of the cytosolic proteins of serovars Typhimurium and Pullorum was performed using two-dimensional gel electrophoresis and the proteins of interest were identified using mass spectrometry. An annotated reference map was created for serovar Typhimurium containing 233 entries, which included many metabolic enzymes, ribosomal proteins, chaperones and many other proteins characteristic for the growing cell. The comparative analysis of the two serovars revealed a high degree of variation amongst isolates obtained from different sources and, in some cases, the variation was greater between isolates of the same serovar than between isolates with different sero-specificity. However, several serovar-specific proteins, including intermediates in sulphate utilisation and cysteine synthesis, were also found despite the fact that the genes encoding those proteins are present in the genomes of both serovars. Conclusion Current microbial proteomics are generally based on the use of a single reference or type strain of a species. This study has shown the importance of incorporating a large number of strains of a species, as the diversity of the proteome in the microbial population appears to be significantly greater than expected. The characterisation of a diverse selection of

A novel Salmonella serovar isolated from Peregrine Falcon (Falco peregrinus nestlings in Sweden: Salmonella enterica enterica serovar Pajala (Salmonella Pajala

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Jorge Hernández

2012-08-01

Full Text Available A novel Salmonella serovar was isolated from Peregrine falcon (Falco peregrinus nestlings in northern Sweden in 2006. Three isolates of the same clone was retrieved from three falcon siblings and characterized as Salmonella enterica sub-species enterica: O-phase 13, 23:-: e, n, z 15 and the H-phase was not present. We propose the geographical name Salmonella enterica, sub-species enterica serovar Pajala to this novel Salmonella.

Detection of Salmonella typhi agglutinins in sera of patients with ...

African Journals Online (AJOL)

Background and Purpose: Widal test is frequently applied for the detection of Salmonella agglutinins to diagnose Salmonella enterica serotype Typhi infection. There are however a number of controversies challenging the diagnostic utility of this test. This study was performed to determine the prevalence of Salmonella ...

Genome-wide methylation patterns in Salmonella enterica Subsp. enterica Serovars.

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Cary Pirone-Davies

Full Text Available The methylation of DNA bases plays an important role in numerous biological processes including development, gene expression, and DNA replication. Salmonella is an important foodborne pathogen, and methylation in Salmonella is implicated in virulence. Using single molecule real-time (SMRT DNA-sequencing, we sequenced and assembled the complete genomes of eleven Salmonella enterica isolates from nine different serovars, and analysed the whole-genome methylation patterns of each genome. We describe 16 distinct N6-methyladenine (m6A methylated motifs, one N4-methylcytosine (m4C motif, and one combined m6A-m4C motif. Eight of these motifs are novel, i.e., they have not been previously described. We also identified the methyltransferases (MTases associated with 13 of the motifs. Some motifs are conserved across all Salmonella serovars tested, while others were found only in a subset of serovars. Eight of the nine serovars contained a unique methylated motif that was not found in any other serovar (most of these motifs were part of Type I restriction modification systems, indicating the high diversity of methylation patterns present in Salmonella.

The emergence of Leptospira borgpetersenii serovar Arborea in Queensland, Australia, 2001 to 2013.

Science.gov (United States)

Lau, Colleen L; Skelly, Chris; Dohnt, Michael; Smythe, Lee D

2015-06-14

Leptospirosis is an emerging infectious disease, with increasing frequency and severity of outbreaks, changing epidemiology of populations at risk, and the emergence of new serovars. Environmental drivers of disease transmission include flooding, urbanisation, poor sanitation, changes in land use and agricultural practices, and socioeconomic factors. In Queensland, human infection with Leptosira borgpetersenii serovar Arborea was first reported in 2001. This study aims to report the emergence of serovar Arborea in Queensland from 2001 to 2013, and investigate potential risk factors for infection and drivers of emergence. Data on laboratory-confirmed cases of human leptospirosis in Queensland were obtained from the enhanced surveillance system at the WHO/FAO/OIE Collaborating Centre for Reference and Research on Leptospirosis in Brisbane, Australia. The changing epidemiology of serovar Arborea from 2001 to 2003 was described with respect to case numbers, proportion of leptospirosis cases attributed to the serovar, and geographic distribution. Differences in risk factors for the most common serovars were compared. During this period, 1289 cases of leptospirosis were reported, including 233 cases attributed to serovar Arborea. Risk factors for infection include male gender (91 % of cases), occupation, and recreational exposure. Most common occupations recorded were banana workers (28.4 %), meat workers (7.2 %), dairy farmers (5.8 %), graziers/stockmen (5.5 %), 'other agricultural/rural workers' (16.4 %), and tourists or tourism operators (4.6 %). Time trend analysis showed that while non-Arborea cases decreased over the study period, Arborea cases increased by 3.4 cases per year. The proportion of annual cases attributed to Arborea peaked at 49 % in 2011 after unprecedented flooding in Queensland. Mapping of cases by residential location showed expansion of the geographic range of serovar Arborea, concentrating mostly around Brisbane, Cairns and Innisfail. Serovars

Design of a Comprehensive Biochemistry and Molecular Biology Experiment: Phase Variation Caused by Recombinational Regulation of Bacterial Gene Expression

Science.gov (United States)

Sheng, Xiumei; Xu, Shungao; Lu, Renyun; Isaac, Dadzie; Zhang, Xueyi; Zhang, Haifang; Wang, Huifang; Qiao, Zheng; Huang, Xinxiang

2014-01-01

Scientific experiments are indispensable parts of Biochemistry and Molecular Biology. In this study, a comprehensive Biochemistry and Molecular Biology experiment about "Salmonella enterica" serovar Typhi Flagellar phase variation has been designed. It consisted of three parts, namely, inducement of bacterial Flagellar phase variation,…

Salmonella Typhimurium undergoes distinct genetic adaption during chronic infections of mice

DEFF Research Database (Denmark)

Søndberg, Emilie; Jelsbak, Lotte

2016-01-01

Background Typhoid fever caused by Salmonella enterica serovar Typhi (S. Typhi) is a severe systemic human disease and endemic in regions of the world with poor drinking water quality and sewage treatment facilities. A significant number of patients become asymptomatic life-long carriers of S....... In the current study genetic adaptation during experimental chronic S. Typhimurium infections of mice, an established model of chronic typhoid fever, was probed as an approach for studying the molecular mechanisms of host-adaptation during long-term host-association. Results Individually sequence-tagged wild...

The response to Typhi Vi vaccination is compromised in individuals with primary immunodeficiency.

Science.gov (United States)

Kumarage, Jeevani; Seneviratne, Suranjith L; Senaratne, Vijitha; Fernando, Amitha; Gunasekera, Kirthi; Gunasena, Bandu; Gurugama, Padmalal; Peiris, Sudath; Parker, Antony R; Harding, Stephen; de Silva, Nilhan Rajiva

2017-06-01

Measurement of an individuals ability to respond to polysaccharide antigens is a crucial test to determine adaptive immunity. Currently the response to Pneumovax ® is utilized but with the success of Prevnar ® , measurement of the response to Pneumovax may be challenging. The aim of the study was to assess the response to Typhi Vi vaccination in both children and adult control groups and patients with primary immunodeficiency (PID). In the control groups, >95% of the individuals had pre Typhi Vi vaccination concentrations 94% achieving ≥3 fold increase in concentration (FI). The response to Typhi Vi vaccination was significantly lower in both children ( p = 0.006) and adult ( p = 0.002) PID groups when compared to their control groups. 11% and 55% of the children and adult PID groups respectively did not obtain a response >3FI. There were no significant differences between the responses obtained in the children and adult PID groups. When all individuals with PID were separated into those with either hypogammaglobulinemia (HYPO) or common variable immunodeficiency (CVID), both groups had a significantly lower median FI than the control group (19, 95%CI 5-56 vs 59, 95%CI 7-237; p = 0.01 and 1, 95%CI 1-56 vs 32, 95%CI 5-136; p = 0.005). Further, a >3FI differentiated the antibody responses between both the CVID and HYPO groups and their control groups (AUC: 0.83, 95%CI: 0.65-1.00, p = 0.005 and 0.81, 95% CI: 0.65-0.97, p = 0.01). The data suggests that measurement of the response to Typhi Vi vaccination could represent a complementary assay for the assessment of the response to a polysaccharide vaccine.

Identification of Five Novel Salmonella Typhi-Specific Genes as Markers for Diagnosis of Typhoid Fever Using Single-Gene Target PCR Assays

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Yuan Xin Goay

2016-01-01

Full Text Available Salmonella Typhi (S. Typhi causes typhoid fever which is a disease characterised by high mortality and morbidity worldwide. In order to curtail the transmission of this highly infectious disease, identification of new markers that can detect the pathogen is needed for development of sensitive and specific diagnostic tests. In this study, genomic comparison of S. Typhi with other enteric pathogens was performed, and 6 S. Typhi genes, that is, STY0201, STY0307, STY0322, STY0326, STY2020, and STY2021, were found to be specific in silico. Six PCR assays each targeting a unique gene were developed to test the specificity of these genes in vitro. The diagnostic sensitivities and specificities of each assay were determined using 39 S. Typhi, 62 non-Typhi Salmonella, and 10 non-Salmonella clinical isolates. The results showed that 5 of these genes, that is, STY0307, STY0322, STY0326, STY2020, and STY2021, demonstrated 100% sensitivity (39/39 and 100% specificity (0/72. The detection limit of the 5 PCR assays was 32 pg for STY0322, 6.4 pg for STY0326, STY2020, and STY2021, and 1.28 pg for STY0307. In conclusion, 5 PCR assays using STY0307, STY0322, STY0326, STY2020, and STY2021 were developed and found to be highly specific at single-gene target resolution for diagnosis of typhoid fever.

Identification of Five Novel Salmonella Typhi-Specific Genes as Markers for Diagnosis of Typhoid Fever Using Single-Gene Target PCR Assays.

Science.gov (United States)

Goay, Yuan Xin; Chin, Kai Ling; Tan, Clarissa Ling Ling; Yeoh, Chiann Ying; Ja'afar, Ja'afar Nuhu; Zaidah, Abdul Rahman; Chinni, Suresh Venkata; Phua, Kia Kien

2016-01-01

Salmonella Typhi ( S . Typhi) causes typhoid fever which is a disease characterised by high mortality and morbidity worldwide. In order to curtail the transmission of this highly infectious disease, identification of new markers that can detect the pathogen is needed for development of sensitive and specific diagnostic tests. In this study, genomic comparison of S . Typhi with other enteric pathogens was performed, and 6 S . Typhi genes, that is, STY0201, STY0307, STY0322, STY0326, STY2020, and STY2021, were found to be specific in silico . Six PCR assays each targeting a unique gene were developed to test the specificity of these genes in vitro . The diagnostic sensitivities and specificities of each assay were determined using 39 S . Typhi, 62 non-Typhi Salmonella , and 10 non- Salmonella clinical isolates. The results showed that 5 of these genes, that is, STY0307, STY0322, STY0326, STY2020, and STY2021, demonstrated 100% sensitivity (39/39) and 100% specificity (0/72). The detection limit of the 5 PCR assays was 32 pg for STY0322, 6.4 pg for STY0326, STY2020, and STY2021, and 1.28 pg for STY0307. In conclusion, 5 PCR assays using STY0307, STY0322, STY0326, STY2020, and STY2021 were developed and found to be highly specific at single-gene target resolution for diagnosis of typhoid fever.

Characterization of Isolates of Salmonella enterica Serovar Stanley, a Serovar Endemic to Asia and Associated with Travel

Science.gov (United States)

Le Hello, Simon; Bortolaia, Valeria; Pulsrikarn, Chaiwat; Nielsen, Eva Møller; Pornruangmong, Srirat; Chaichana, Phattharaporn; Svendsen, Christina Aaby; Weill, François-Xavier; Aarestrup, Frank M.

2012-01-01

Salmonella enterica serovar Stanley (S. Stanley) is a common serovar in Southeast Asia and was the second most common serovar implicated in human salmonellosis in Thailand in the years 2002 to 2007. In contrast, this serovar is relatively uncommon in Europe. The objective of this study was to characterize a collection of S. Stanley strains isolated from Thai (n = 62), Danish (n = 39), and French (n = 24) patients to gain a broader understanding of the genetic diversity, population dynamics, and susceptibility to antimicrobials. All isolates were characterized by pulsed-field gel electrophoresis and antimicrobial susceptibility testing. The molecular mechanisms of resistance to extended-spectrum cephalosporins and plasmid-mediated resistance to quinolones were characterized by PCR and sequencing. Plasmid profiling, replicon typing, and microarray analysis were used to characterize the genetic mechanisms of antimicrobial resistance in 10 extended-spectrum cephalosporinase-producing isolates. Considerable genetic diversity was observed among the isolates characterized with 91 unique XbaI pulsed-field gel electrophoresis (PFGE) patterns, including 17 distinct clusters consisting of two to seven indistinguishable isolates. We found some of the S. Stanley isolates isolated from patients in Europe were acquired during travel to Southeast Asia, including Thailand. The presence of multiple plasmid lineages carrying the extended-spectrum cephalosporinase-encoding blaCMY-2 gene in S. Stanley isolates from the central part of Thailand was confirmed. Our results emphasize that Thai authorities, as well as authorities in other countries lacking prudent use of antimicrobials, should improve the ongoing efforts to regulate antimicrobial use in agriculture and in clinical settings to limit the spread of multidrug-resistant Salmonella isolates and plasmids among humans and pigs in Thailand and abroad. PMID:22205822

Influence of subinhibitory-concentration (sub-MIC Cefetoxime on biofilm formation. SEM study of ESBL-producing Salmonella typhi

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Rahul Narasanna, Manjunath Chavadi, Ajaykumar Oli

2017-06-01

Full Text Available Objectives: In the present study, we have analyzed ESBL-producing S. typhi’s capability in forming a significant amount of biofilm on plastic and glass surface, and the influence of cefetoxime on biofilm development at subinhibitory (Sub-MIC concentration. Methods: Nine strains of cefetoxime-mediated ESBL-producing S. typhi were used in the study. S. typhi formed biofilm on plastic and glass materials; it was demonstrated using micro titre plate (MTP and standard test tube methods. Comparative study of the influence of cefetoxime on biofilm formation in its MIC (128 µg/ml and at sub-MIC (64 µg/ml was demonstrated by microtitre plate method. The biofilm production was observed in SEM images, statistical analysis (ANOVA showed significant increase in cell surface and volume due to the influence of Cefetoxime. Results: Of the nine selected isolates, two S. typhi strains, namely BST 51 and BST 130, produced relatively strong biofilm in the presence of cefetoxime at sub-MIC level (64 µg/ml, comparatively weak biofilm formation at MIC level (128 µg/ml. Typical morphological changes were observed in cefetoxime-resistant strains, S. typhi BST 51 and BST 130, in comparison to cefetoxime-sensitive strain S. typhi BST 63 used as a control. We found an increase in surface and volume of a cell in response to cefetoxime and statistical data (ANOVA proved that resistant strains were significantly different from control strains. Conclusion: The above study clearly shows that cefetoxime at sub-MIC level efficiently induces biofilm formation and promotes changes in morphology of the cell. J Microbiol Infect Dis 2017; 7(2: 67-75

Oral Wild-Type Salmonella Typhi Challenge Induces Activation of Circulating Monocytes and Dendritic Cells in Individuals Who Develop Typhoid Disease.

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Franklin R Toapanta

2015-06-01

Full Text Available A new human oral challenge model with wild-type Salmonella Typhi (S. Typhi was recently developed. In this model, ingestion of 104 CFU of Salmonella resulted in 65% of subjects developing typhoid fever (referred here as typhoid diagnosis -TD- 5-10 days post-challenge. TD criteria included meeting clinical (oral temperature ≥38°C for ≥12 h and/or microbiological (S. Typhi bacteremia endpoints. One of the first lines of defense against pathogens are the cells of the innate immune system (e.g., monocytes, dendritic cells -DCs-. Various changes in circulating monocytes and DCs have been described in the murine S. Typhimurium model; however, whether similar changes are present in humans remains to be explored. To address these questions, a subset of volunteers (5 TD and 3 who did not develop typhoid despite oral challenge -NoTD- were evaluated for changes in circulating monocytes and DCs. Expression of CD38 and CD40 were upregulated in monocytes and DCs in TD volunteers during the disease days (TD-0h to TD-96h. Moreover, integrin α4β7, a gut homing molecule, was upregulated on monocytes but not DCs. CD21 upregulation was only identified in DCs. These changes were not observed among NoTD volunteers despite the same oral challenge. Moreover, monocytes and DCs from NoTD volunteers showed increased binding to S. Typhi one day after challenge. These monocytes showed phosphorylation of p38MAPK, NFkB and Erk1/2 upon stimulation with S. Typhi-LPS-QDot micelles. In contrast, monocytes from TD volunteers showed only a moderate increase in S. Typhi binding 48 h and 96 h post-TD, and only Erk1/2 phosphorylation. This is the first study to describe different activation and migration profiles, as well as differential signaling patterns, in monocytes and DCs which relate directly to the clinical outcome following oral challenge with wild type S. Typhi.

Growth and survival of Salmonella Paratyphi A in roasted marinated chicken during refrigerated storage: Effect of temperature abuse and computer simulation for cold chain management

Science.gov (United States)

This research was conducted to evaluate the feasibility of using a one-step dynamic numerical analysis and optimization method to directly construct a tertiary model to describe the growth and survival of Salmonella Paratyphi A (SPA) in a marinated roasted chicken product. Multiple dynamic growth a...

Anti-biofilm efficacy of 100 MeV gold ion irradiated polycarbonate against Salmonella typhi

Science.gov (United States)

Joshi, R. P.; Hareesh, K.; Bankar, A.; Sanjeev, G.; Asokan, K.; Kanjilal, D.; Dahiwale, S. S.; Bhoraskar, V. N.; Dhole, S. D.

2017-12-01

Polycarbonate (PC) films were irradiated by 100 MeV gold (Au7+) ions and characterized to study changes in its optical, chemical, surface morphology and thermal properties. UV-Visible spectroscopic results revealed the decrease in the optical band gap of PC after ion irradiation due to chain scission mainly at the carbonyl group which is corroborated by Fourier Transform Infrared spectroscopic results. X-ray diffractogram study showed decrease in crystallinity of PC film after irradiation. Scanning electron microscopic results showed the micropores formation in PC which results in surface roughening. Differential scanning calorimetric results revealed decrease in glass transition temperature indicating the decrease in molecular weight of PC corroborated by rheometric studies. PC films irradiated by 100 MeV Au7+ ions showed increased anti-biofilm activity against the human pathogen, Salmonella typhi (S. typhi). Morphology of S. typhi was changed due to stress of Au7+ irradiated PC. Cells length was increased with increasing fluences. The average cell length, cell volume and surface area was increased significantly (PBiofilm formation was inhibited ≈ 20% at lower fluence and 96% at higher fluence, which observed to be enhanced anti-biofilm activity in Au7+ irradiated PC.

Salmonella typhi time to change empiric treatment

DEFF Research Database (Denmark)

Gade, C.; Engberg, J.; Weis, N.

2008-01-01

In the present case series report we describe seven recent cases of typhoid fever. All the patients were travellers returning from Pakistan, where typhoid is endemic. Salmonella typhi isolated from the patients by blood culture were reported as intermediary susceptible to fluoroquinolones in six...... out of seven cases. We recommend that empiric treatment of suspected cases of typhoid fever includes a third generation cephalosporin such as ceftriaxon. Furthermore, the present report stresses the importance of typhoid vaccination of travellers to areas where typhoid is endemic Udgivelsesdato: 2008/9/29...

A Randomised Trial Evaluating the Safety and Immunogenicity of the Novel Single Oral Dose Typhoid Vaccine M01ZH09 in Healthy Vietnamese Children

NARCIS (Netherlands)

Tran, T.H.; Nguyen, T.D.; Nguyen, T.T.; Ninh, T.T.V.; Tran, N.B.C.; Nguyen, V.M.H.; Tran, T.T.N.; Cao, T.T.; Pham, V.M.; Nguyen, T.C.B.; Tran, T.D.H.; Pham, V.T.; To, S.D.; Campbell, J.I.; Stockwell, E.; Schultsz, C.; Simmons, C.P.; Glover, C.; Lam, W.; Marques, F.; May, J.P.; Upton, A.; Budhram, R.; Dougan, G.; Farrar, J.; Nguyen, V.V.C.; Dolecek, C.

2010-01-01

Background: The emergence of drug resistant typhoid fever is a major public health problem, especially in Asia. An oral single dose typhoid vaccine would have major advantages. M01ZH09 is a live oral single dose candidate typhoid vaccine containing Salmonella enterica serovar Typhi (Ty2 aroC(-)

Cloning and expression of a Vi mimotope of Salmonella enterica ...

African Journals Online (AJOL)

STORAGESEVER

2009-09-15

Sep 15, 2009 ... A recombinant His-Vi protein of Salmonella enterica serovar Typhi was successfully constructed and cloned into ... mainly through consumption of food or water contami- nated with .... and healthy individuals (double arrows) followed by the detection using recombinant His-Vi protein as the primary antibody ...

Association of carcinoma of the gallbladder with typhoid carriage in a typhoid endemic area using nested PCR.

Science.gov (United States)

Nath, Gopal; Singh, Yogesh Kumar; Kumar, Kailash; Gulati, Anil Kumar; Shukla, Vijay Kumar; Khanna, Ajay Kumar; Tripathi, Sunil Kumar; Jain, Ashok Kumar; Kumar, Mohan; Singh, Tej Bali

2008-08-30

Although well studied the association between chronic typhoid carrier state and carcinoma of the gallbladder (CaGB) remains unproven. The study was performed at a tertiary care medical center in North India and involved 52 patients with CaGB, 223 patients with benign gallbladder diseases, 508 healthy individuals and, 424 corpses. For the detection of Salmonella enterica serovar Typhi, hepatobiliary specimens were subjected to DNA extraction for specific nested- PCR amplification of the S. Typhi flagellin gene. Anti-Vi S. Typhi antibodies were detected in serum samples from patients by indirect haemagglutination. Thirty five of the 52 (67.3%) CaGB patients were PCR-positive for the S. Typhi flagellin gene; significantly higher than for patients with benign gallbladder diseases (95/223, 42.6%; p or = 160) in their serum were 20/52 (38.5%) for CaGB patients, 31/223 (13.9%) for patients with benign gallbladder diseases, and 47/508 (9.2%) for healthy individuals. Specific nested-PCR amplification of the S. Typhi flagellin gene in hepato-biliary specimens was more sensitive for detection of S. Typhi carriage than anti-Vi antibody titres in serum. The results demonstrate an association between typhoid carriage and gallbladder diseases, both CaGB and benign. S. Typhi specific immunosuppression is also suggested in patients with gallbladder diseases.

A severe Salmonella enterica serotype Paratyphi B infection in a child related to a pet turtle, Trachemys scripta elegans.

Science.gov (United States)

Nagano, Noriyuki; Oana, Shinji; Nagano, Yukiko; Arakawa, Yoshichika

2006-04-01

Our report highlights a case of severe childhood salmonellosis related to a pet turtle, a red-eared slider (Trachemys scripta elegans). A 6-year-old girl had gastroenteritis complicated with sepsis caused by serotype Paratyphi B, which shared the same pulsed-field gel electrophoresis profiles with the organism isolated from a pet turtle. Based on our literature survey on childhood invasive salmonellosis acquired from reptiles, this case is the first documented reptile-associated salmonellosis including sepsis caused by this serotype.

Vi-CRM 197 as a new conjugate vaccine against Salmonella Typhi.

Science.gov (United States)

Micoli, F; Rondini, S; Pisoni, I; Proietti, D; Berti, F; Costantino, P; Rappuoli, R; Szu, S; Saul, A; Martin, L B

2011-01-17

An efficacious, low cost vaccine against typhoid fever, especially for young children, would make a major impact on disease burden in developing countries. The virulence capsular polysaccharide of Salmonella Typhi (Vi) coupled to recombinant mutant Pseudomonas aeruginosa exoprotein A (Vi-rEPA) has been shown to be highly efficacious. We investigated the use of carrier proteins included in infant vaccines, standardized the conjugation process and developed key assays required for routine lot release at production scale. Vi from a BSL1 organism, Citrobacter freundii, strain WR7011, was used as an alternative to Vi from S. Typhi. We showed that Vi conjugated to CRM(197), a non-toxic mutant of diphtheria toxin, widely used in commercial vaccines, was produced at high yield. Vi-CRM(197) proved immunogenic in animal studies, even without adjuvant. Thus, Vi-CRM(197) appears to be a suitable candidate for the development of a commercially viable, effective typhoid vaccine for developing countries. Copyright © 2010 Elsevier Ltd. All rights reserved.

An evaluation of purified Salmonella Typhi protein antigens for the serological diagnosis of acute typhoid fever.

Science.gov (United States)

Tran Vu Thieu, Nga; Trinh Van, Tan; Tran Tuan, Anh; Klemm, Elizabeth J; Nguyen Ngoc Minh, Chau; Voong Vinh, Phat; Pham Thanh, Duy; Ho Ngoc Dan, Thanh; Pham Duc, Trung; Langat, Pinky; Martin, Laura B; Galan, Jorge; Liang, Li; Felgner, Philip L; Davies, D Huw; de Jong, Hanna K; Maude, Rapeephan R; Fukushima, Masako; Wijedoru, Lalith; Ghose, Aniruddha; Samad, Rasheda; Dondorp, Arjen M; Faiz, Abul; Darton, Thomas C; Pollard, Andrew J; Thwaites, Guy E; Dougan, Gordon; Parry, Christopher M; Baker, Stephen

2017-08-01

The diagnosis of typhoid fever is a challenge. Aiming to develop a typhoid diagnostic we measured antibody responses against Salmonella Typhi (S. Typhi) protein antigens and the Vi polysaccharide in a cohort of Bangladeshi febrile patients. IgM against 12 purified antigens and the Vi polysaccharide was measured by ELISA in plasma from patients with confirmed typhoid fever (n = 32), other confirmed infections (n = 17), and healthy controls (n = 40). ELISAs with the most specific antigens were performed on plasma from 243 patients with undiagnosed febrile disease. IgM against the S. Typhi protein antigens correlated with each other (rho > 0.8), but not against Vi (rho Typhoid patients exhibited higher IgM against 11/12 protein antigens and Vi than healthy controls and those with other infections. Vi, PilL, and CdtB exhibited the greatest sensitivity and specificity. Specificity and sensitivity was improved when Vi was combined with a protein antigen, generating sensitivities and specificities of 0.80 and >0.85, respectively. Applying a dynamic cut-off to patients with undiagnosed febrile disease suggested that 34-58% had an IgM response indicative of typhoid. We evaluated the diagnostic potential of several S. Typhi antigens; our assays give good sensitivity and specificity, but require further assessment in differing patient populations. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Daya Antibakteri dan Waktu Kontak Infusa Teh Hijau (Camellia sinensis Terhadap Salmonella typhi Secara In Vitro

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Dione Margareth Setiawan

2010-06-01

Full Text Available Green tea (Camellia sinensis contains cathecin which has been reported to have various pharmacologic properties, such as an antibacterial agent. Salmonella typhi, as agent of typhoid fever, remains a public health problem in tropical countries; about 20 million cases and 600.000 deaths annually all over the world. Objectives of this research were to observe the antibacterial activities and contact time of green tea infusion againsts Salmonella typhi by in vitro experiment. The experiment took place in Microbiology Laboratory, School of Medicine, Padjadjaran University, Bandung, March-April 2009. Methods: In vitro laboratory analytic study has been conducted on green tea infusion of Indonesian and Japanese commercial package againsts Salmonella typhi. The study used agar well diffusion method and analyzed by ANAVA and t-independent test. Results: Only at concentration of 40% (w/v, Indonesian green tea infusion gave an average inhibition area of 3.376±0.334 mm diameter, and 3.571±0.217 mm on Japanese package, while below 40% were 0.707±0.000 mm with no differences between both packages (p>0.551. There has been observed any turbidity in all Muller Hinton liquid media on both packages compared with control medium, also any growth of Salmonella typhi collony in all Muller Hinton agar at concentrations below 40%. Green tea infussion on both packages has been observed to have antibacterial activities at 40% but neither been observed at concentration below 40%.

The Prevalence and Antibiotic Susceptibility Pattern of Salmonella typhi among Patients Attending a Military Hospital in Minna, Nigeria

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N. U. Adabara

2012-01-01

Full Text Available The threat to human health posed by antibiotic-resistant bacterial pathogens is of growing concern to medical practice. This study investigated the antibiotic sensitivity pattern of Salmonella typhi isolated from blood specimen. One hundred blood samples were collected from suspected typhoid fever patients in 31 Artillery Brigade Medical Centre, Minna, and were analyzed for S. typhi while antibiotic sensitivity testing was done Kirby-Bauer method. Sixty (60.0% samples out of the total 100 were positive for bacterial growth. The organisms isolated 2 include Salmonella typhi; 45 (75.0%, Shigella; 6 (10.0%, E. coli; 3 (5.0%, Klebsiella; 3 (5.0%, Enterobacter; 2 (3.3%, and Citrobacter; 1 (1.7%. Result of the sensitivity test showed that the isolates were resistant to all the antibiotics; ceftriaxone, cefuroxime, amoxicillin, ampicillin, ciprofloxacin, and augmentin, which are the drug of choice routinely used in the study area for the treatment of typhoid fever. They were however sensitive to chloramphenicol and ofloxacin, which, unfortunately, are not used in this study area for the treatment of typhoid fever. There appear to be multiple drug resistant (MDR strain of S. typhi in the study area. These may be as a result of overdependence or uncontrolled use of the few available antibiotics and/or inaccurate or inconclusive diagnosis resulting in the development and spread of resistant strains of S. typhi. The study, therefore, highlights the need for a strong collaboration between the physicians and the laboratory in the choice of antibiotics for the treatment of bacterial diseases in order to discourage the development of resistant strain of bacterial pathogen.

Characterization of Leptospira interrogans serovar Pomona isolated from swine in Brazil

NARCIS (Netherlands)

Miraglia, Fabiana; Moreno, Luisa Z.; Morais, Zenaide M.; Langoni, Helio; Shimabukuro, Fabio H.; Dellagostin, Odir A.; Hartskeerl, Rudy; Vasconcellos, Silvio A.; Moreno, Andrea Micke

2015-01-01

Leptospira interrogans swine infection is a cause of serious economic loss and a potential human health hazard. In Brazil, the most common serovars associated with swine infections are Pomona, Icterohaemorrhagie and Tarassovi. Cross-reactions among serovars and the failure of infected animals to

Epidemiology, clinical manifestations, and molecular typing of salmonella typhi isolated from patients with typhoid fever in Lebanon.

Science.gov (United States)

Kanj, Souha S; Kanafani, Zeina A; Shehab, Marwa; Sidani, Nisreen; Baban, Tania; Baltajian, Kedak; Dakdouki, Ghenwa K; Zaatari, Mohamad; Araj, George F; Wakim, Rima Hanna; Dbaibo, Ghassan; Matar, Ghassan M

2015-06-01

The objective of this study was to examine the epidemiology and the clinical manifestations of typhoid fever as well as the susceptibility and strain relatedness of Salmonella typhi isolates in Lebanon from 2006 to 2007. A total of 120 patients with typhoid fever were initially identified from various areas of the country based on positive culture results for S. typhi from blood, urine, stools, bone marrow and/or positive serology. Clinical, microbiological and molecular analysis was performed on cases with complete data available. These results indicated that drinking water was an unlikely mode of transmission of the infection. Despite increasing reports of antimicrobial resistance among S. typhi isolates, the vast majority of these isolates were susceptible to various antibiotic agents, including ampicillin, cephalosporins, quinolones, and trimethoprim/sulfamethoxazole. Molecular analysis of the isolates revealed a predominance of one single genotype with no variation in distribution across the geographical regions. Copyright © 2014 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

Detection of Salmonella enterica Serovar Typhimurium from Avians Using Multiplex-PCR

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Alireza Talebi

2011-09-01

Full Text Available Abstract Salmonella enterica serovar Typhimurium and S.enterica serovar Enteritidis are the most frequently isolated serovars from food-borne diseases throughout the world. According to their antigenic profiles, salmonella shows different disease syndromes and host specificities. It is necessary and important to discriminate salmonella serovars from each other in order to ensure that each pathogen and its epidemiology are correctly recognized. Many PCR-based methods have been developed to identify salmonella serovars. The objective of present study was to identify S. Typhimurium in avians from different regions including: North, Northwest and capital city (Tehran of Iran. Also in this research, the quality of CHROMagar™ Salmonella medium (CAS medium in veterinary medicine was evaluated. The results of present study showed that out of 1870 intestine samples, fifty two S. Typhimurium including broiler (n=13, layer (n=12, duck (n=5, goose (n=5, sparrow (n=8, canary (n=3, pigeon (n=5 and African grey parrot (n=1 were identified using serotyping as well as multiplex-PCR. In conclusion, important measures must be taken on prevention and propagation of S. Typhimurium among avians. CHROMagar™ Salmonella medium has high levels of sensitivity and specificity and reduced the time to final identification of salmonella spp. in comparison with biochemical tests.

In Vitro Effect of New Antibiotics Against Clinical Isolates of Salmonella Typhi

International Nuclear Information System (INIS)

Malik, N.

2016-01-01

Objective: To determine the in vitrodisk diffusion and MIC patterns of the therapeutic alternatives for Salmonella Typhi. Study Design: Across-sectional study. Place and Duration of Study: Armed Forces Institute of Pathology, Rawalpindi, from June 2011 to May 2013. Methodology: Clinical samples were collected from suspected cases of Salmonella infections. Culture was obtained on standard media. Suspected Salmonella colonies were tested by API 20E and confirmed by serology. The isolates were tested for resistance to various antibiotics by Kirby-Bauer disc diffusion method. MIC was done on MDR and ciprofloxacin intermediate or resistant cases by E-strips for selected antibiotics. Results: One hundred and twenty-eight isolates of Salmonella Typhi were recovered from 2230 specimens. Resistance by disk diffusion technique was 72% for ampicillin, 41.2% for cotrimoxazole, 38% for chloramphenicol, 8% for ciprofloxacin, 4.7% for cefpodoxime, 3.5% each for ertapenem aztreonam and moxifloxacin 2.4% for ceftriaxone and 2.3% for doripenem. No resistance was noted for imipenem, cefepime and gatifloxacin. Imipenem MIC90 was 0.38 and MIC50 was 0.25. For cefpirome, MIC90 was 0.64 and MIC50 was 0.09. For aztreonam, MIC90 was 0.12 and MIC50 was 0.09. For cefpodoxime MIC90 was 0.75 and MIC50 was 0.38. For azithromycin, these values were 16.0 and 7.0; and for tigecycline they were 0.25 and 0.09. Conclusion: Imipenem, azithromycin, tigecycline, aztreonam, cefpodoxime and cefpirome are potential therapeutic agents for resistant Salmonella Typhi infection. (author)

Complete genome sequence of Leptospira interrogans serovar Bratislava, strain PigK151

Science.gov (United States)

The genus Leptospira contains pathogens serologically classified into over 250 serovars, intermediate pathogens and saprophytes with genetic classification into 21 different species. Worldwide, leptospirosis is one of the most widespread zoonoses. L. interrogans serovar Bratislava has been isolated ...

Acquired homotypic and heterotypic immunity against oculogenital Chlamydia trachomatis serovars following female genital tract infection in mice

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Peña A Salvador

2005-11-01

Full Text Available Abstract Background Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen causing female genital tract infection throughout the world. Reinfection with the same serovar, as well as multiple infections with different serovars, occurs in humans. Using a murine model of female C. trachomatis genital tract infection, we determined if homotypic and/or heterotypic protection against reinfection was induced following infection with human oculogenital strains of C. trachomatis belonging to two serovars (D and H that have been shown to vary significantly in the course of infection in the murine model. Methods Groups of outbred CF-1 mice were reinfected intravaginally with a strain of either serovar D or H, two months after initial infection with these strains. Cellular immune and serologic status, both quantitative and qualitative, was assessed following initial infection, and the course of infection was monitored by culturing vaginal samples collected every 2–7 days following reinfection. Results Serovar D was both more virulent (longer duration of infection and immunogenic (higher level of circulating and vaginal IgG and higher incidence of IgA in vaginal secretions in the mouse genital tract. Although both serovars induced cross-reacting antibodies during the course of primary infection, prior infection with serovar H resulted in only a slight reduction in the median duration of infection against homotypic reinfection (p ~ 0.10, while prior infection with serovar D resulted in significant reduction in the median duration of infection against both homotypic (p Conclusion Serovar D infection resulted in significant homotypic and heterotypic protection against reinfection, while primary infection with serovar H resulted in only slight homotypic protection. In addition to being the first demonstration of acquired heterotypic immunity between human oculogenital serovars, the differences in the level and extent of this immunity

Typhoid Fever Complicated by Hemophagocytic Lymphohistiocytosis and Rhabdomyolysis.

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Non, Lemuel R; Patel, Rupa; Esmaeeli, Amir; Despotovic, Vladimir

2015-11-01

Hemophagocytic lymphohistiocytosis (HLH) and rhabdomyolysis are rare complications of typhoid fever from Salmonella enterica serovar Typhi. Herein, we describe the clinical features in a 21-year-old female from India who presented to the intensive care unit with fever, severe pancytopenia, and rhabdomyolysis. © The American Society of Tropical Medicine and Hygiene.

A randomised trial evaluating the safety and immunogenicity of the novel single oral dose typhoid vaccine M01ZH09 in healthy Vietnamese children

NARCIS (Netherlands)

Tran, Tinh Hien; Nguyen, Thi Dung; Nguyen, Thanh Truong; Ninh, Thi Thanh Van; Tran, Nguyen Bich Chau; Nguyen, Van Minh Hoang; Tran, Thi Thu Nga; Cao, Thu Thuy; Pham, Van Minh; Nguyen, Thi Cam Binh; Tran, Thi Diem Ha; Pham, Van Toi; To, Song Diep; Campbell, James I.; Stockwell, Elaine; Schultsz, Constance; Simmons, Cameron P.; Glover, Clare; Lam, Winnie; Marques, Filipe; May, James P.; Upton, Anthony; Budhram, Ronald; Dougan, Gordon; Farrar, Jeremy; Nguyen, Van Vinh Chau; Dolecek, Christiane

2010-01-01

The emergence of drug resistant typhoid fever is a major public health problem, especially in Asia. An oral single dose typhoid vaccine would have major advantages. M01ZH09 is a live oral single dose candidate typhoid vaccine containing Salmonella enterica serovar Typhi (Ty2 aroC(-)ssaV(-)) ZH9 with

Complete genome sequence of Leptospira alstonii serovar room 22, strain GWTS#1

Science.gov (United States)

We report the complete genome sequence of Leptospira alstonii serovar room 22 strain GWTS#1. This is the first isolate of L. alstonii to be cultured from a mammal, in Western Europe, and represents a new serovar of pathogenic leptospires....

Whole Genome Sequence Analysis of Salmonella Typhi Isolated in Thailand before and after the Introduction of a National Immunization Program.

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Zoe A Dyson

2017-01-01

Full Text Available Vaccines against Salmonella Typhi, the causative agent of typhoid fever, are commonly used by travellers, however, there are few examples of national immunization programs in endemic areas. There is therefore a paucity of data on the impact of typhoid immunization programs on localised populations of S. Typhi. Here we have used whole genome sequencing (WGS to characterise 44 historical bacterial isolates collected before and after a national typhoid immunization program that was implemented in Thailand in 1977 in response to a large outbreak; the program was highly effective in reducing typhoid case numbers. Thai isolates were highly diverse, including 10 distinct phylogenetic lineages or genotypes. Novel prophage and plasmids were also detected, including examples that were previously only reported in Shigella sonnei and Escherichia coli. The majority of S. Typhi genotypes observed prior to the immunization program were not observed following it. Post-vaccine era isolates were more closely related to S. Typhi isolated from neighbouring countries than to earlier Thai isolates, providing no evidence for the local persistence of endemic S. Typhi following the national immunization program. Rather, later cases of typhoid appeared to be caused by the occasional importation of common genotypes from neighbouring Vietnam, Laos, and Cambodia. These data show the value of WGS in understanding the impacts of vaccination on pathogen populations and provide support for the proposal that large-scale typhoid immunization programs in endemic areas could result in lasting local disease elimination, although larger prospective studies are needed to test this directly.

The diagnostic accuracy of three rapid diagnostic tests for typhoid fever at Chittagong Medical College Hospital, Chittagong, Bangladesh.

Science.gov (United States)

Maude, Rapeephan R; de Jong, Hanna K; Wijedoru, Lalith; Fukushima, Masako; Ghose, Aniruddha; Samad, Rasheda; Hossain, Mohammed Amir; Karim, Mohammed Rezaul; Faiz, Mohammed Abul; Parry, Christopher M

2015-10-01

To determine the diagnostic accuracy of three rapid diagnostic tests (RDTs) for typhoid fever in febrile hospitalised patients in Bangladesh. Febrile adults and children admitted to Chittagong Medical College Hospital, Bangladesh, were investigated with Bact/Alert(®) blood cultures and real-time PCR to detect Salmonella enterica Typhi and Paratyphi A and assays for Rickettsia, leptospirosis and dengue fever. Acute serum samples were examined with the LifeAssay (LA) Test-it™ Typhoid IgM lateral flow assay detecting IgM antibodies against S. Typhi O antigen, CTKBiotech Onsite Typhoid IgG/IgM Combo Rapid-test cassette lateral flow assay detecting IgG and IgM antibodies against S. Typhi O and H antigens and SD Bioline line assay for IgG and IgM antibodies against S. Typhi proteins. In 300 malaria smear-negative febrile patients [median (IQR) age of 13.5 (5-31) years], 34 (11.3%) had confirmed typhoid fever: 19 positive by blood culture for S. Typhi (three blood PCR positive) and 15 blood culture negative but PCR positive for S. Typhi in blood. The respective sensitivity and specificity of the three RDTs in patients using a composite reference standard of blood culture and/or PCR-confirmed typhoid fever were 59% and 61% for LifeAssay, 59% and 74% for the CTK IgM and/or IgG, and 24% and 96% for the SD Bioline RDT IgM and/or IgG. The LifeAssay RDT had a sensitivity of 63% and a specificity of 91% when modified with a positive cut-off of ≥2+ and analysed using a Bayesian latent class model. These typhoid RDTs demonstrated moderate diagnostic accuracies, and better tests are needed. © 2015 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

Non-crosslinking gold nanoprobe-LAMP for simple, colorimetric, and specific detection of Salmonella typhi

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Bozorgmehr, Ali; Yazdanparast, Razieh, E-mail: ryazdan@ut.ac.ir [University of Tehran, Institute of Biochemistry and Biophysics (Iran, Islamic Republic of); Mollasalehi, Hamidreza [Shahid Beheshti University, Protein Research Center (Iran, Islamic Republic of)

2016-12-15

In this study, we developed a non-crosslinking gold nanoprobe loop-mediated isothermal amplification (LAMP) method for nanodiagnosis of bacterial typhoid fever source, Salmonella typhi. Therefore, a unique region in the S. typhi genomic DNA was targeted for LAMP amplification using a specific set of four precisely designed primers. Also, for specific colorimetric visualization of the amplicons, a thiolated oligonucleotide probe, complementary to the single-stranded loop region of the amplicons between F2 and F1C segments, was designed. The probe was bound to the surface of gold nanoparticles via covalent bonds. Increasing the salt concentration in the detection reaction medium led to aggregation of nanoprobes in the blank and the negative vessels in a time-dependent form. That was followed by a change in the surface plasmon resonance (SPR) leading to blue/black color that was observable by the naked eyes after about 5 min. Meanwhile, the original pink/red color was retained in the positive sample due to the large interparticle spaces and the stability against the ionic strength elevation which persisted for about 30 min. The whole process of DNA extraction, amplification, and detection took less than 2 h with a sensitivity of 20 CFU/ml. The developed gold nanoprobe-LAMP could serve as a simple, rapid, and cost-effective method for nanodiagnosis of S. typhi in point-of-need applications.

Direct evidence of Rickettsia typhi infection in Rhipicephalus sanguineus ticks and their canine hosts

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Karla Dzul-Rosado

2017-06-01

Full Text Available Murine typhus is a rickettsiosis caused by Rickettsia typhi, whose transmission is carried out by rat fleas in urban settlements as classically known, but it also has been related to cat fleas in a sub-urban alternative cycle that has been suggested by recent reports. These studies remarks that in addition to rats, other animals like cats, opossums and dogs could be implied in the transmission of Rickettsia typhi as infected fleas obtained from serologically positive animals have been detected in samples from endemic areas. In Mexico, the higher number of murine typhus cases have been detected in the Yucatan peninsula, which includes a great southeastern region of Mexico that shows ecologic characteristics similar to the sub-urban alternative cycle recently described in Texas and California at the United States. To find out which are the particular ecologic characteristics of murine typhus transmission in this region, we analyzed blood and Rhipicephalus sanguineus ticks obtained from domestic dogs by molecular approaches, demonstrating that both samples were infected by Rickettsia typhi. Following this, we obtained isolates that were analyzed by genetic sequencing to corroborate this infection in 100% of the analyzed samples. This evidence suggests for the first time that ticks and dogs could be actively participating in the transmission of murine typhus, in a role that requires further studies for its precise description.

Non-crosslinking gold nanoprobe-LAMP for simple, colorimetric, and specific detection of Salmonella typhi

International Nuclear Information System (INIS)

Bozorgmehr, Ali; Yazdanparast, Razieh; Mollasalehi, Hamidreza

2016-01-01

In this study, we developed a non-crosslinking gold nanoprobe loop-mediated isothermal amplification (LAMP) method for nanodiagnosis of bacterial typhoid fever source, Salmonella typhi. Therefore, a unique region in the S. typhi genomic DNA was targeted for LAMP amplification using a specific set of four precisely designed primers. Also, for specific colorimetric visualization of the amplicons, a thiolated oligonucleotide probe, complementary to the single-stranded loop region of the amplicons between F2 and F1C segments, was designed. The probe was bound to the surface of gold nanoparticles via covalent bonds. Increasing the salt concentration in the detection reaction medium led to aggregation of nanoprobes in the blank and the negative vessels in a time-dependent form. That was followed by a change in the surface plasmon resonance (SPR) leading to blue/black color that was observable by the naked eyes after about 5 min. Meanwhile, the original pink/red color was retained in the positive sample due to the large interparticle spaces and the stability against the ionic strength elevation which persisted for about 30 min. The whole process of DNA extraction, amplification, and detection took less than 2 h with a sensitivity of 20 CFU/ml. The developed gold nanoprobe-LAMP could serve as a simple, rapid, and cost-effective method for nanodiagnosis of S. typhi in point-of-need applications.

Ureaplasma serovars & their antimicrobial susceptibility in patients of infertility & genital tract infections.

Science.gov (United States)

Dhawan, Benu; Malhotra, Neena; Sreenivas, Vishnubhatla; Rawre, Jyoti; Khanna, Neena; Chaudhry, Rama; Mittal, Suneeta

2012-12-01

Ureaplasmas have been implicated in a variety of clinical conditions. However, only certain serovars of ureaplasmas are disease associated. Only a few classes of antimicrobial agents are available for the treatment of mycoplasmal infections in humans. Increase of resistance of genital mycoplasmas to antimicrobials has been reported worldwide. The aim of the present study was to determine the occurrence of Ureaplasma serovars in patients with infertility and genital tract infections with polymerase chain reaction (PCR)-based serotyping. The antimicrobial susceptibilities of Ureaplasma spp. and Mycoplasma hominis were also assessed to determine the most suitable treatment strategy. Sexually active adults (n=147) with symptoms of genital tract infections and 115 infertile women were enrolled. Endocervical swabs from women and urethral swabs from men were subjected to culture and multiplex PCR for detection of genital mycoplasmas. Serotyping of Ureaplasma was done by PCR and antimicrobial susceptibility to doxycycline, azithromycin, josamycin and ofloxacin was done by microbroth dilution method. Ureaplasma was detected in 25.8 per cent patients with genital tract infections and 20.8 per cent in infertile women. Serovar 3/14 was the most frequent isolate followed by serovar 1 and serovar 6. The majority of Ureaplasma isolates were susceptible to doxycycline (91%) and josamycin (86%) followed by ofloxacin (77%) and azithromycin (71%). All the isolates of M. hominis were uniformly susceptible to doxycycline, josamycin and ofloxacin. The predominance of Ureaplasma serovar 3/14 suggests their possible pathogenic role in genital tract infections and infertility. For empirical treatment, doxycycline could be the drug of choice for genital mycoplasmas.

Chlamydia trachomatis serovar G infection in a bisexual male with urethritis.

Science.gov (United States)

Rawre, Jyoti; Dhawan, Benu; Saigal, Karnika; Khanna, Neena

2016-01-01

We report a case of Chlamydia trachomatis serovar G urogenital tract infection in a 33-year-old human immunodeficiency virus-1 (HIV-1) seropositive Indian bisexual male. This case highlights the emergence of a new serovar in India. The patient was tested positive for C. trachomatis by both cryptic plasmid and omp A gene polymerase chain reaction (PCR). On further characterization using polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) and omp A gene sequencing, the strain was found to be C. trachomatis serovar G. His spouse was also found to be infected with C. trachomatis serovar G. Phylogenetic analysis was performed on the clinical isolates obtained from both partners and were found to be identical to the isolates available in GenBank. The sexual network could not be traced further. Detection of a new genotype suggests importation of a new strain into the population probably by sexual contact with a person from a geographical area where the strain is common. Identifying circulating genotypes in the community can assist in developing strategies for improved sexually transmitted disease control.

Six new leptospiral serovars isolated from wild animals in Peru.

OpenAIRE

Liceras de Hidalgo, J L; Sulzer, K R

1984-01-01

Six new serovars of Leptospira interrogans were isolated from opossums (Didelphis marsupialis and Philander opossum) trapped in the Peruvian jungle. The proposed names, type strain designation, and serogroup of the serovars, respectively, were: huallaga, strain M-7, Djasiman serogroup; luis, strain M-6, Tarassovi serogroup; machiguenga, strain MMD-3, Icterohaemorrhagiae serogroup; rioja, strain MR-12, Bataviae serogroup; rupa rupa, strain M-3, Sejroe serogroup; and tingomaria, strain M-13, Cy...

Animal salmonelloses: a brief review of “host adaptation and host specificity” of Salmonella spp.

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Grammato Evangelopoulou

2013-07-01

Full Text Available Salmonella enterica, the most pathogenic species of the genusSalmonella, includes more than 2,500 serovars, many of which are of great veterinary and medical significance. The emergence of food-borne pathogens, such as Salmonella spp., has increased knowledge about the mechanisms helping microorganisms to persist and spread within new host populations. It has also increased information about the properties they acquire for adapting in the biological environment of a new host. Thedifferences observed between serovars in their host preference and clinical manifestations are referred to as “serovar-host specificity” or “serovar-host adaptation”. The genus Salmonella, highly adaptive to vertebrate hosts, has many pathogenic serovars showing host specificity. Serovar Salmonella Typhi, causing disease to man and higher primates, is a good example of host specificity. Thus, understanding the mechanisms that Salmonella serovars use to overcome animal species' barriers or adapt to new hosts is also important for understanding the origins of any other infectious diseases or the emergence of new pathogens. In addition, molecular methods used to study the virulence determinants of Salmonella serovars, could also be used to model ways of studying the virulence determinants used by bacteria in general, when causing disease to a specific animal species

Serum bactericidal assay for the evaluation of typhoid vaccine using a semi-automated colony-counting method.

Science.gov (United States)

Jang, Mi Seon; Sahastrabuddhe, Sushant; Yun, Cheol-Heui; Han, Seung Hyun; Yang, Jae Seung

2016-08-01

Typhoid fever, mainly caused by Salmonella enterica serovar Typhi (S. Typhi), is a life-threatening disease, mostly in developing countries. Enzyme-linked immunosorbent assay (ELISA) is widely used to quantify antibodies against S. Typhi in serum but does not provide information about functional antibody titers. Although the serum bactericidal assay (SBA) using an agar plate is often used to measure functional antibody titers against various bacterial pathogens in clinical specimens, it has rarely been used for typhoid vaccines because it is time-consuming and labor-intensive. In the present study, we established an improved SBA against S. Typhi using a semi-automated colony-counting system with a square agar plate harboring 24 samples. The semi-automated SBA efficiently measured bactericidal titers of sera from individuals immunized with S. Typhi Vi polysaccharide vaccines. The assay specifically responded to S. Typhi Ty2 but not to other irrelevant enteric bacteria including Vibrio cholerae and Shigella flexneri. Baby rabbit complement was more appropriate source for the SBA against S. Typhi than complements from adult rabbit, guinea pig, and human. We also examined the correlation between SBA and ELISA for measuring antibody responses against S. Typhi using pre- and post-vaccination sera from 18 human volunteers. The SBA titer showed a good correlation with anti-Vi IgG quantity in the serum as determined by Spearman correlation coefficient of 0.737 (P measure functional antibody titers against S. Typhi in sera from human subjects immunized with typhoid vaccines. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Peculiarities of S.Typhi isolation from the river water polluted with radionuclides at different times of the year

Energy Technology Data Exchange (ETDEWEB)

Toichuev, R. M. [Institute of Medical Problems of the Southern Branch, Osh(Kyrgyzstan)

2012-09-15

Full text:Objective: to assess the effect of radionuclide pollution of river water on the isolation rate of S. Tuphi at different times of the year. Materials and methods: Since the number of typhoid fever cases reported in the Mayluusuu Valley (23 tailing pits and 16 tailing dumps are located in the area) tends to increase after the mudslides we collected river water specimens considering all these factors. Water specimens were collected from the Mayluusuu River, Shaidan-sai River, Kara-Unkur River and Ak-Buura River. Bacterial inoculation was performed in accordance with standard procedures. Concentration levels of pesticides (DDT, DDE, DDD, GCCG {alpha}, {beta}, {gamma} Aldrin and Dieldrin) were measured with a spectrograph. The present work was done in the framework of the ISTC Project KR-1516. Results and discussion: Out of the total of 2360 water specimens collected from the Shaidan-Sai River, S. Typhi was isolated from one (0.04%) water specimen. No cases of S. Typhi isolation from the water specimens collected from the Kara-Unkur River were reported for the past 10 years. Out of the total of 8969 water specimens collected from the Ak-Buura River, isolation of S. Typhi was reported in 4 (0.044%) cases. Starting from 2006 typhoid fever cases have been reported in the winter and spring times among the residents of the Mayluusuu Valley. A total of 1200 patients with a presumptive diagnosis of typhoid fever were admitted to the hospitals during the period. S. Typhi was isolated from 2 out of the total of 51 (3.9%) water specimens collected from the Mayluusuu River in the winter time, 4 (2.4%) out of the total 164 - in the spring time, 3.4% and 4.5% in the summer and autumn, respectively. Concentration levels of thorium (Th) and uranium (U) were 0.025-0.045 mg/l and 0.35-15.0 mg/l. No traces of the pesticides were found in water specimens. DDE at concentration of 0.024 mg/l and GCCG {alpha} (0.06 mg/l) were found in silt specimens collected downstream the Ak

A Unique Capsule Locus in the Newly Designated Actinobacillus pleuropneumoniae Serovar 16 and Development of a Diagnostic PCR Assay.

Science.gov (United States)

Bossé, Janine T; Li, Yanwen; Sárközi, Rita; Gottschalk, Marcelo; Angen, Øystein; Nedbalcova, Katerina; Rycroft, Andrew N; Fodor, László; Langford, Paul R

2017-03-01

Actinobacillus pleuropneumoniae causes pleuropneumonia, an economically significant lung disease of pigs. Recently, isolates of A. pleuropneumoniae that were serologically distinct from the previously characterized 15 serovars were described, and a proposal was put forward that they comprised a new serovar, serovar 16. Here we used whole-genome sequencing of the proposed serovar 16 reference strain A-85/14 to confirm the presence of a unique capsular polysaccharide biosynthetic locus. For molecular diagnostics, primers were designed from the capsule locus of strain A-85/14, and a PCR was formulated that differentiated serovar 16 isolates from all 15 known serovars and other common respiratory pathogenic/commensal bacteria of pigs. Analysis of the capsule locus of strain A-85/14 combined with the previous serological data show the existence of a sixteenth serovar-designated serovar 16-of A. pleuropneumoniae . Copyright © 2017 Bossé et al.

Antibacterial effect of mango (Mangifera indica Linn.) leaf extract against antibiotic sensitive and multi-drug resistant Salmonella typhi.

Science.gov (United States)

Hannan, Abdul; Asghar, Samra; Naeem, Tahir; Ikram Ullah, Muhammad; Ahmed, Ijaz; Aneela, Syeda; Hussain, Shabbir

2013-07-01

Alternative herbal medicine has been used to treat various infections from centuries. Natural plants contain phytoconstituents having similar chemical properties as of synthetic antibiotics. Typhoid fever is a serious infection and failure of its treatment emerged multi-drug resistant (MDR) bugs of Salmonella typhi. Due to multiple and repeated issues with antibiotics efficacy, it became essential to evaluate biological properties of plants from different geographical origins. Mango leaves have been Reported for various medicinal effects like antioxidant, antimicrobial, antihelminthic, antidiabetic and antiallergic etc. Objective of present study was to investigate anti-typhoid properties of acetone mango leaf extract (AMLE) against antibiotic sensitive and MDR S. typhi isolates. A total of 50 isolates of S. typhi including MDR (n=30) and antibiotic sensitive (n=20) were investigated. Staphylococcus aureus (ATCC 25923) and Salmonella typhimurium (ATCC14028) were used as quality control strains. AMLE was prepared and its antibacterial activity was evaluated by agar well diffusion screening method and minimum inhibitory concentration (MIC), by agar dilution technique. Zone of inhibition (mm) of AMLE against MDR and antibiotic sensitive isolates was 18±1.5mm (Mean±S.D). Zone of S. aureus (ATCC 25923) and S. typhimurium (ATCC14028) was 20±1.5mm (Mean±S.D). MIC of AMLE was Reported in range from 10-50 mg/ml. The present study described the inhibitory effects of mango leaves against S. typhi.

Bilateral breast abscesses due to Salmonella Enterica serotype typhi

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Gagandeep Singh

2011-01-01

Full Text Available Focal infection is an uncommon complication of Salmonella septicemia, particularly in immunocompetent patients. The localization of Salmonella infection to breast tissue is regarded as a rare event. We report a case of bilateral breast abscesses due to Salmonella enterica serotype Typhi in a nonlactating female and highlight the fact that Salmonella spp. should be included in differential diagnosis of abscesses in individuals coming from endemic areas with the history of recent typhoid fever and should be treated accordingly.

Survival and Filamentation of Salmonella enterica Serovar Enteritidis PT4 and Salmonella enterica Serovar Typhimurium DT104 at Low Water Activity

Science.gov (United States)

Mattick, K. L.; Jørgensen, F.; Legan, J. D.; Cole, M. B.; Porter, J.; Lappin-Scott, H. M.; Humphrey, T. J.

2000-01-01

In this study we investigated the long-term survival of and morphological changes in Salmonella strains at low water activity (aw). Salmonella enterica serovar Enteritidis PT4 and Salmonella enterica serovar Typhimurium DT104 survived at low aw for long periods, but minimum humectant concentrations of 8% NaCl (aw, 0.95), 96% sucrose (aw, 0.94), and 32% glycerol (aw, 0.92) were bactericidal under most conditions. Salmonella rpoS mutants were usually more sensitive to bactericidal levels of NaCl, sucrose, and glycerol. At a lethal aw, incubation at 37°C resulted in more rapid loss of viability than incubation at 21°C. At aw values of 0.93 to 0.98, strains of S. enterica serovar Enteritidis and S. enterica serovar Typhimurium formed filaments, some of which were at least 200 μm long. Filamentation was independent of rpoS expression. When the preparations were returned to high-aw conditions, the filaments formed septa, and division was complete within approximately 2 to 3 h. The variable survival of Salmonella strains at low aw highlights the importance of strain choice when researchers produce modelling data to simulate worst-case scenarios or conduct risk assessments based on laboratory data. The continued increase in Salmonella biomass at low aw (without a concomitant increase in microbial count) would not have been detected by traditional microbiological enumeration tests if the tests had been performed immediately after low-aw storage. If Salmonella strains form filaments in food products that have low aw values (0.92 to 0.98), there are significant implications for public health and for designing methods for microbiological monitoring. PMID:10742199

Presence of antibodies against Leptospira serovars in Chaetophractus villosus (Mammalia, Dasypodidae), La Pampa province, Argentina.

Science.gov (United States)

Kin, Marta S; Brihuega, Bibiana; Fort, Marcelo; Delgado, Fernando; Bedotti, Daniel; Casanave, Emma B

2015-01-01

Leptospirosis is a zoonosis of worldwide distribution. The aim of this study was to examine the presence of antibodies against 21 Leptospira reactive serovars in Chaetophractus villosus in La Pampa province, Argentina, using the microscopic agglutination test (MAT). Pathologic changes compatible with leptospirosis and in situ detection of the agent by immunohistochemistry were studied in 24 and 3 individuals respectively. Only 35/150 (23.3%) serum samples had antibodies against Leptospira sp. Six percent of the samples reacted with serovar Canicola, 4.7% with serovar Castellonis, 1.3% with serovar Icterohemorrhagieae and 0.7% with serovar Hardjo. Sixteen (10.6%) serum samples agglutinated with Castellonis-Icterohemorrhagiae and Canicola-Castellonis serovars, both with 4.7%, and Canicola-Hardjo and Castellonis-Canicola-Icterohemorrhagiae both with 0.6%. Fourteen animals had variable degrees of lesions, which were more severe in animals with higher serological titers (3200), and Leptospira sp. was detected in 3 animals by immunohistochemistry. These results represent the first record of the presence of Leptospira in C. villosus in La Pampa. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Salmonella typhi--tid til aendring af den empiriske behandling

DEFF Research Database (Denmark)

Gade, Christina; Engberg, Jørgen; Weis, Nina

2008-01-01

In the present case series report we describe seven recent cases of typhoid fever. All the patients were travellers returning from Pakistan, where typhoid is endemic. Salmonella typhi isolated from the patients by blood culture were reported as intermediary susceptible to fluoroquinolones in six...... out of seven cases. We recommend that empiric treatment of suspected cases of typhoid fever includes a third generation cephalosporin such as ceftriaxon. Furthermore, the present report stresses the importance of typhoid vaccination of travellers to areas where typhoid is endemic. Udgivelsesdato: 2008...

Study of the role of efflux pump in ciprofloxacin resistance in Salmonella enterica serotype Typhi

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V Sharma

2013-01-01

Full Text Available Purpose: There are increasing reports on failure of clinical response to ciprofloxacin in typhoid fever despite the strain being sensitive to drug in in-vitro using standard guidelines and showing mutations in DNA gyrase. But this increased MIC and clinical failures with ciprofloxacin are not always co-related with mutations presently identified in gyrA and parC genes. This shows that there may be other mechanisms such as an active drug efflux pump responsible as has been shown in other Enterobacteriaceae. This study was carried out to determine the role of efflux pump in Salmonella Typhi isolates. Materials and Methods : Total 25 already characterized nalidixic acid sensitive and nalidixic acid resistant S. Typhi strains with different range of ciprofloxacin MIC were included to study the role of efflux pump in the presence of CCCP (efflux pump inhibitor. For genotypic characterization, the entire acrR gene was sequenced to confirm the presence of any mutation in the gene. Results: The MIC of ciprofloxacin remained same in the presence and absence of CCCP in the studied strains and no significant mutations were found in the acrR gene in any of the isolates studied. Conclusions: No role of efflux pump in ciprofloxacin resistance was found in strains studied. There is a need to explore further mechanism of ciprofloxacin resistance in Salmonella Typhi.

Prevalence of Salmonella spp., and serovars isolated from captive exotic reptiles in New Zealand.

Science.gov (United States)

Kikillus, K H; Gartrell, B D; Motion, E

2011-07-01

To investigate the prevalence of Salmonella spp. in captive exotic reptile species in New Zealand, and identify the serovars isolated from this population. Cloacal swabs were obtained from 378 captive exotic reptiles, representing 24 species, residing in 25 collections throughout New Zealand between 2008 and 2009. Samples were cultured for Salmonella spp., and suspected colonies were serotyped by the Institute of Environmental Science and Research (ESR). Forty-three of the 378 (11.4%) reptiles sampled tested positive for Salmonella spp., with 95% CI for the estimated true prevalence being 12-25% in exotic reptiles in this study population. Lizards tested positive for Salmonella spp. more often than chelonians. Agamid lizards tested positive more often than any other family group, with 95% CI for the estimated true prevalence being 56-100%.. Six Salmonella serovars from subspecies I and two from subspecies II were isolated. The serovar most commonly isolated was S. Onderstepoort (30.2%), followed by S. Thompson (20.9%), S. Potsdam (14%), S. Wangata (14%), S. Infantis (11.6%) and S. Eastbourne (2.3%). All of the subspecies I serovars have been previously reported in both reptiles and humans in New Zealand, and include serovars previously associated with disease in humans. This study showed that Salmonella spp. were commonly carried by exotic reptiles in the study population in New Zealand. Several serovars of Salmonella spp. with known pathogenicity to humans were isolated, including S. Infantis, which is one of the most common serovars isolated from both humans and non-human sources in New Zealand. The limitations of this study included the bias engendered by the need for voluntary involvement in the study, and the non-random sampling design. Based on the serovars identified in this and previous studies, it is recommended native and exotic reptiles be segregated within collections, especially when native reptiles may be used for biodiversity restoration

Influence of Environmental Factors and Human Activity on the Presence of Salmonella Serovars in a Marine Environment

Science.gov (United States)

Martinez-Urtaza, Jaime; Saco, Montserrat; de Novoa, Jacobo; Perez-Piñeiro, Pelayo; Peiteado, Jesus; Lozano-Leon, Antonio; Garcia-Martin, Oscar

2004-01-01

The temporal and spatial distribution of Salmonella contamination in the coastal waters of Galicia (northwestern Spain) relative to contamination events with different environmental factors (temperature, wind, hours of sunlight, rainfall, and river flow) were investigated over a 4-year period. Salmonellae were isolated from 127 of 5,384 samples of molluscs and seawater (2.4%), and no significant differences (P < 0.05) between isolates obtained in different years were observed. The incidence of salmonellae was significantly higher in water column samples (2.9%) than in those taken from the marine benthos (0.7%). Of the 127 strains of Salmonella isolated, 20 different serovars were identified. Salmonella enterica serovar Senftenberg was the predominant serovar, being represented by 54 isolates (42.5%), followed by serovar Typhimurium (19 isolates [15%]) and serovar Agona (12 isolates [9.4%]). Serovar Senftenberg was detected at specific points on the coast and could not be related to any of the environmental parameters analyzed. All serovars except Salmonella serovar Senftenberg were found principally in the southern coastal areas close to the mouths of rivers, and their incidence was associated with high southwestern wind and rainfall. Using multiple logistic regression analysis models, the prevalence of salmonellae was best explained by environmental parameters on the day prior to sampling. Understanding this relationship may be useful for the control of molluscan shellfish harvests, with wind and rainfall serving as triggers for closure. PMID:15066800

A study of Salmonella typhi isolated in Suez Canal area. Biotyping, phage typing and colicinogenic property.

Science.gov (United States)

Shoeb, S; Khalifa, I; el Daly, O; Heiba, A; Farmer, J; Brenner, F; el Batawi, Y

1989-01-01

In this work a total of 82 strains of Salmonella typhi were isolated from Egyptian patients diagnosed as quiry enteric fever. These cases were from Ismalia, Suez and port Said Areas. The strains fell in 16 phage types. Phage types N, 40, E1, and degraded Vi were the commonest phage type in Ismailia, while phage types degraded Vi and C1 were the commonest in Port Said. Phage types Di-N, degraded Vi, A and C1 were the commonest in Suez. Chemotyping of Salmonella typhi showed that the majority of the strains belonged to chemotype I (82%), and the rest belonged to chemotype II (18%). Colicin production was negative and all the strains were susceptible to the currently used antibiotics.

Cloning and Sequencing of Gene Encoding Outer Membrane Lipoprotein LipL41 of Leptospira Interrogans Serovar Grippotyphosa

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M.S. Soltani

2014-12-01

Full Text Available Background: Leptospirosis is an infectious bacterial disease caused by pathogenic serovars of Leptospira. Development of reliable and applicable diagnostic test and also recombinant vaccine for this disease require specific antigens that are highly conserved among diverse pathogenic leptospiral serovars. Outer membrane proteins(OMPs of leptospira are effective antigens which can stimulate remarkable immune responses during infection, among them LipL41 is an immunogenic lipoprotein which is present only in pathogenic serovars so it could be regarded as a good candidate for vaccine development and diagnostic method. In order to identify genetic conservation of the lipL41 gene, we cloned and sequenced this gen from Leptospira interrogans serovar vaccinal and field of Grippotyphosa. Materials and Methods: Leptospira interrogans serovar vaccinal Grippotyphosa (RTCC2808 and serovar field Grippotyphosa (RTCC2825were used to inoculate into the selective culture medium(EMJH. The genomic DNA was extracted by standard phenol-chloroform method. The lipL41 gene were amplified by specific primers and cloned into pTZ57R/T vector and transformed into the competent E. coli (Top10 cells. the extracted recombinant plasmid were sequenced. And the related sequences were subjected to homology analysis by comparing them to sequences in the Genbank database. Results: PCR amplification of the lipL41 gene resulted in the 1065 bp PCR product. DNA sequence analysis revealed that lipL41 gene between serovar vaccinal Grippotyphosa (RTCC2808and serovar field Grippotyphosa (RTCC2825 in Iran was 100%. It was also showed that the lipL41 gene had high identity (96%-100% with other pathogenic serovars submitted in Genbank database. Conclusion: The results of this study showed that the lipL41 gene was highly conserved among various pathogenic Leptospira serovars( >95.9 % identity. Hence the cloned gene could be further used for expression of recombinant protein for serodiagnosis

Identification of Leptospira serovars by RFLP of the RNA polymerase beta subunit gene (rpoB

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Lenice Roteia Cardoso Jung

2015-06-01

Full Text Available Leptospires are usually classified by methods based on DNA-DNA hybridization and the conventional cross-agglutination absorption test, which uses polyclonal antibodies against lipopolysaccharides. In this study, the amplification of the rpoB gene, which encodes the beta-subunit of RNA polymerase, was used as an alternative tool to identify Leptospira. DNA extracts from sixty-eight serovars were obtained, and the hypervariable region located between 1990 and 2500-bp in the rpoB gene was amplified by polymerase chain reaction (PCR. The 600-bp amplicons of the rpoB gene were digested with the restriction endonucleases TaqI, Tru1I, Sau3AI and MslI, and the restriction fragments were separated by 6% polyacrylamide gel electrophoresis. Thirty-five fragment patters were obtained from the combined data of restriction fragment length polymorphism (PCR-RFLP analysis and used to infer the phylogenetic relationships among the Leptospira species and serovars. The species assignments obtained were in full agreement with the established taxonomic classifications. Twenty-two serovars were effectively identified based on differences in their molecular profiles. However, the other 46 serovars remained clustered in groups that included more than one serovar of different species. This study demonstrates the value of RFLP analysis of PCR-amplified rpoB as an initial method for identifying Leptospira species and serovars.

Identification of Leptospira serovars by RFLP of the RNA polymerase beta subunit gene (rpoB).

Science.gov (United States)

Jung, Lenice Roteia Cardoso; Bomfim, Maria Rosa Quaresma; Kroon, Erna Geessien; Nunes, Álvaro Cantini

2015-06-01

Leptospires are usually classified by methods based on DNA-DNA hybridization and the conventional cross-agglutination absorption test, which uses polyclonal antibodies against lipopolysaccharides. In this study, the amplification of the rpoB gene, which encodes the beta-subunit of RNA polymerase, was used as an alternative tool to identify Leptospira. DNA extracts from sixty-eight serovars were obtained, and the hypervariable region located between 1990 and 2500-bp in the rpoB gene was amplified by polymerase chain reaction (PCR). The 600-bp amplicons of the rpoB gene were digested with the restriction endonucleases TaqI, Tru1I, Sau3AI and MslI, and the restriction fragments were separated by 6% polyacrylamide gel electrophoresis. Thirty-five fragment patters were obtained from the combined data of restriction fragment length polymorphism (PCR-RFLP) analysis and used to infer the phylogenetic relationships among the Leptospira species and serovars. The species assignments obtained were in full agreement with the established taxonomic classifications. Twenty-two serovars were effectively identified based on differences in their molecular profiles. However, the other 46 serovars remained clustered in groups that included more than one serovar of different species. This study demonstrates the value of RFLP analysis of PCR-amplified rpoB as an initial method for identifying Leptospira species and serovars.

Characterization of putative multidrug resistance transporters of the major facilitator-superfamily expressed in Salmonella Typhi

DEFF Research Database (Denmark)

Shaheen, Aqsa; Ismat, Fouzia; Iqbal, Mazhar

2015-01-01

Multidrug resistance mediated by efflux pumps is a well-known phenomenon in infectious bacteria. Although much work has been carried out to characterize multidrug efflux pumps in Gram-negative and Gram-positive bacteria, such information is still lacking for many deadly pathogens. The aim...... of this study was to gain insight into the substrate specificity of previously uncharacterized transporters of Salmonella Typhi to identify their role in the development of multidrug resistance. S. Typhi genes encoding putative members of the major facilitator superfamily were cloned and expressed in the drug......-hypersensitive Escherichia coli strain KAM42, and tested for transport of 25 antibacterial compounds, including representative antibiotics of various classes, antiseptics, dyes and detergents. Of the 15 tested putative transporters, STY0901, STY2458 and STY4874 exhibited a drug-resistance phenotype. Among these, STY4874...

Lymphogranuloma Venereum-Serovar L2b Presenting With Painful Genital Ulceration: An Emerging Clinical Presentation?

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Haber, Roger; Maatouk, Ismaël; de Barbeyrac, Bertille; Bagot, Martine; Janier, Michel; Fouéré, Sébastien

2017-05-01

These 5 cases of atypical inflammatory lymphogranula venereum (LGV) serovar L2b presenting initially with edema and persistent painful ulceration illustrate that clinical manifestations of LGV in the current outbreak in men who have sex with men reflect the influence of both the serovars virulence and the host immune system and are not confined to proctitis. L2b serovar could have a particular high virulence profile, and the need for awareness of LGV as a cause of genital ulceration is crucial.

Development of Hamster Models for Acute and Chronic Infections with Leptospira borgpetersenii serovar Hardjo

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The Golden Syrian hamster is frequently used as a small animal model to study acute leptospirosis. However, use of this small animal model to study Leptospira borgpetersenii serovar Hardjo infections has not been well documented. Cattle are the normal maintenance hosts of L. borgpetersenii serovar...

Prevalence and antimicrobial profiles of Salmonella serovars from ...

African Journals Online (AJOL)

ADEYEYE

2014-01-21

Jan 21, 2014 ... Presumptive Salmonella isolates were determined by using the conventional ... Salmonella represents a major contaminant of vegetables consumed in Maiduguri, North-eastern ... serovars in vegetables in Nigeria do not exist.

A novel method of selective removal of human DNA improves PCR sensitivity for detection of Salmonella Typhi in blood samples.

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Zhou, Liqing; Pollard, Andrew J

2012-07-27

Enteric fever is a major public health problem, causing an estimated 21million new cases and 216,000 or more deaths every year. Current diagnosis of the disease is inadequate. Blood culture only identifies 45 to 70% of the cases and is time-consuming. Serological tests have very low sensitivity and specificity. Clinical samples obtained for diagnosis of enteric fever in the field generally have blood, so that even PCR-based methods, widely used for detection of other infectious diseases, are not a straightforward option in typhoid diagnosis. We developed a novel method to enrich target bacterial DNA by selective removal of human DNA from blood samples, enhancing the sensitivity of PCR tests. This method offers the possibility of improving PCR assays directly using clinical specimens for diagnosis of this globally important infectious disease. Blood samples were mixed with ox bile for selective lysis of human blood cells and the released human DNA was then digested with addition of bile resistant micrococcal nuclease. The intact Salmonella Typhi bacteria were collected from the specimen by centrifugation and the DNA extracted with QIAamp DNA mini kit. The presence of Salmonella Typhi bacteria in blood samples was detected by PCR with the fliC-d gene of Salmonella Typhi as the target. Micrococcal nuclease retained activity against human blood DNA in the presence of up to 9% ox bile. Background human DNA was dramatically removed from blood samples through the use of ox bile lysis and micrococcal nuclease for removal of mammalian DNA. Consequently target Salmonella Typhi DNA was enriched in DNA preparations and the PCR sensitivity for detection of Salmonella Typhi in spiked blood samples was enhanced by 1,000 fold. Use of a combination of selective ox-bile blood cell lysis and removal of human DNA with micrococcal nuclease significantly improves PCR sensitivity and offers a better option for improved typhoid PCR assays directly using clinical specimens in diagnosis of

Rickettsia typhi IN RODENTS AND R. felis IN FLEAS IN YUCATÁN AS A POSSIBLE CAUSAL AGENT OF UNDEFINED FEBRILE CASES

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Gaspar PENICHE-LARA

2015-04-01

Full Text Available Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study’s results contributed to a better knowledge of Rickettsia epidemiology in Yucatán.

Draft Genome Sequence of Leptospira interrogans Serovar Bataviae Strain LepIMR 22 Isolated from a Rodent in Johor, Malaysia

NARCIS (Netherlands)

Amran, Fairuz; Mohd Khalid, Mohd Khairul Nizam; Mohamad, Saharuddin; Mat Ripen, Adiratna; Ahmad, Norazah; Goris, Marga G. A.; Muhammad, Ayu Haslin; Noor Halim, Nurul Atiqah

2016-01-01

Leptospira interrogans serovar Bataviae was recently identified as one of the persistent Leptospira serovars in Malaysia. Here, we report the draft genome sequence of the L. interrogans serovar Bataviae strain LepIMR 22 isolated from kidney of a rodent in Johor, Malaysia

Circulating serovars of Leptospira in cart horses of central and southern Ethiopia and associated risk factors.

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Tsegay, K; Potts, A D; Aklilu, N; Lötter, C; Gummow, B

2016-03-01

Little work has been done on diseases of horses in Ethiopia or tropical regions of the world. Yet, Ethiopia has the largest horse population in Africa and their horses play a pivotal role in their economy as traction animals. A serological and questionnaire survey was therefore conducted to determine the circulating serovars of Leptospira and their association with potential risk factors in the cart horse population of Central and Southern Ethiopia. A total of 184 out of 418 cart horses from 13 districts had antibody titres of 1:100 or greater to at least one of 16 serovars of Leptospira species in Central and Southern Ethiopian horses. A significantly higher seropositivity (62.1%) was noted in horses from the highland agroecology followed by midland (44.4%) and lowland (39.8%). Serovar Bratislava (34.5%) was the predominant serovar followed by serovars Djasiman (9.8%), Topaz (5.98%) and Pomona (5.3%). Age and location proved to be associated with seropositive horses with older horses being more commonly affected and the districts of Ziway (Batu) (Apparent Prevalence (AP)=65.5%), Shashemene (AP=48.3%) and Sebeta (AP=41.4%) having the highest prevalence. Multivariable logistic regression found risk factors significantly associated with Leptospira seropositive horses were drinking river water (OR=2.8) and horses 7-12 years old (OR=5) and risk factors specifically associated with serovar Bratislava seropositive horses were drinking river water (OR=2.5), horses ≥13 years (OR=3.5) and the presence of dogs in adjacent neighbouring properties (OR=0.3). Dogs had a protective effect against seropositivity to serovars Bratislava and Djasiman, which may be due to their ability to control rodents. The high seroprevalence confirm that leptospirosis is endemic among horses of Central and Southern Ethiopia. The predominance of serovar Bratislava supports the idea that serovar Bratislava may be adapted to and maintained by the horse population of Central and Southern Ethiopia

Comparative genomic analysis of Brazilian Leptospira kirschneri serogroup Pomona serovar Mozdok

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Luisa Z Moreno

2016-08-01

Full Text Available Leptospira kirschneri is one of the pathogenic species of the Leptospira genus. Human and animal infection from L. kirschneri gained further attention over the last few decades. Here we present the isolation and characterisation of Brazilian L. kirschneri serogroup Pomona serovar Mozdok strain M36/05 and the comparative genomic analysis with Brazilian human strain 61H. The M36/05 strain caused pulmonary hemorrhagic lesions in the hamster model, showing high virulence. The studied genomes presented high symmetrical identity and the in silico multilocus sequence typing analysis resulted in a new allelic profile (ST101 that so far has only been associated with the Brazilian L. kirschneri serogroup Pomona serovar Mozdok strains. Considering the environmental conditions and high genomic similarity observed between strains, we suggest the existence of a Brazilian L. kirschneri serogroup Pomona serovar Mozdok lineage that could represent a high public health risk; further studies are necessary to confirm the lineage significance and distribution.

Chlamydia trachomatis serovars of endemic trachoma had been ...

African Journals Online (AJOL)

Journal of Applied Sciences and Environmental Management ... The serovars that we identified from Japanese infants and pregnant women ... Once Japan was thought to be belong to an endemic area of trachoma as other Asian countries.

A comparative study of Widal test with blood culture in the diagnosis of typhoid fever in febrile patients.

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Andualem, Gizachew; Abebe, Tamrat; Kebede, Nigatu; Gebre-Selassie, Solomon; Mihret, Adane; Alemayehu, Haile

2014-09-17

Typhoid fever is a major health problem in developing countries and its diagnosis on clinical ground is difficult. Diagnosis in developing countries including Ethiopia is mostly done by Widal test. However, the value of the test has been debated. Hence, evaluating the result of this test is necessary for correct interpretation of the result. The main aim of this study was to compare the result of Widal test and blood culture in the diagnosis of typhoid fever in febrile patients. Blood samples were collected from 270 febrile patients with symptoms clinically similar to typhoid fever and visiting St. Paul's General Specialized Hospitals from mid December 2010 to March 2011. Blood culture was used to isolate S.typhi and S.paratyphi. Slide agglutination test and tube agglutination tests were used for the determination of antibody titer. An antibody titer of ≥1:80 for anti TO and ≥1:160 for anti TH were taken as a cut of value to indicate recent infection of typhoid fever. One hundred and eighty six (68.9%) participants were females and eighty four (31.1%) were males. 7 (2.6%) cases of S. typhi and 4 (1.5%) cases of S. paratyphi were identified with the total prevalence of typhoid fever 4.1%. The total number of patients who have indicative of recent infection by either of O and H antigens Widal test is 88 (32.6%). The sensitivity, specificity, Positive predictive Value and Negative predictive Value of Widal test were 71.4%, 68.44%, 5.7% and 98.9% respectively. Widal test has a low sensitivity, specificity and PPV, but it has good NPV which indicates that negative Widal test result have a good indication for the absence of the disease.

Human genetic variation in VAC14 regulates Salmonella invasion and typhoid fever through modulation of cholesterol.

Science.gov (United States)

Alvarez, Monica I; Glover, Luke C; Luo, Peter; Wang, Liuyang; Theusch, Elizabeth; Oehlers, Stefan H; Walton, Eric M; Tram, Trinh Thi Bich; Kuang, Yu-Lin; Rotter, Jerome I; McClean, Colleen M; Chinh, Nguyen Tran; Medina, Marisa W; Tobin, David M; Dunstan, Sarah J; Ko, Dennis C

2017-09-12

Risk, severity, and outcome of infection depend on the interplay of pathogen virulence and host susceptibility. Systematic identification of genetic susceptibility to infection is being undertaken through genome-wide association studies, but how to expeditiously move from genetic differences to functional mechanisms is unclear. Here, we use genetic association of molecular, cellular, and human disease traits and experimental validation to demonstrate that genetic variation affects expression of VAC14, a phosphoinositide-regulating protein, to influence susceptibility to Salmonella enterica serovar Typhi ( S Typhi) infection. Decreased VAC14 expression increased plasma membrane cholesterol, facilitating Salmonella docking and invasion. This increased susceptibility at the cellular level manifests as increased susceptibility to typhoid fever in a Vietnamese population. Furthermore, treating zebrafish with a cholesterol-lowering agent, ezetimibe, reduced susceptibility to S Typhi. Thus, coupling multiple genetic association studies with mechanistic dissection revealed how VAC14 regulates Salmonella invasion and typhoid fever susceptibility and may open doors to new prophylactic/therapeutic approaches.

Shell-vial culture and real-time PCR applied to Rickettsia typhi and Rickettsia felis detection.

Science.gov (United States)

Segura, Ferran; Pons, Immaculada; Pla, Júlia; Nogueras, María-Mercedes

2015-11-01

Murine typhus is a zoonosis transmitted by fleas, whose etiological agent is Rickettsia typhi. Rickettsia felis infection can produces similar symptoms. Both are intracellular microorganisms. Therefore, their diagnosis is difficult and their infections can be misdiagnosed. Early diagnosis prevents severity and inappropriate treatment regimens. Serology can't be applied during the early stages of infection because it requires seroconversion. Shell-vial (SV) culture assay is a powerful tool to detect Rickettsia. The aim of the study was to optimize SV using a real-time PCR as monitoring method. Moreover, the study analyzes which antibiotics are useful to isolate these microorganisms from fleas avoiding contamination by other bacteria. For the first purpose, SVs were inoculated with each microorganism. They were incubated at different temperatures and monitored by real-time PCR and classical methods (Gimenez staining and indirect immunofluorescence assay). R. typhi grew at all temperatures. R. felis grew at 28 and 32 °C. Real-time PCR was more sensitive than classical methods and it detected microorganisms much earlier. Besides, the assay sensitivity was improved by increasing the number of SV. For the second purpose, microorganisms and fleas were incubated and monitored in different concentrations of antibiotics. Gentamicin, sufamethoxazole, trimethoprim were useful for R. typhi isolation. Gentamicin, streptomycin, penicillin, and amphotericin B were useful for R. felis isolation. Finally, the optimized conditions were used to isolate R. felis from fleas collected at a veterinary clinic. R. felis was isolated at 28 and 32 °C. However, successful establishment of cultures were not possible probably due to sub-optimal conditions of samples.

Cross neutralizing antibodies in hamsters vaccinated with leptospiral bacterins produced with three serovars of serogroup Sejroe

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Rosana Tabata

2002-09-01

Full Text Available Three leptospiral bacterins, produced with different serovars of Serogroup Sejroe, namely the hardjo (bacterin A, wolffi (bacterin B and guaricura (bacterin C, were evaluated in male hamsters (Mesocricetus auratus by comparing the agglutinating and neutralizing antibodies titers using microscopic agglutination (MAT and in vitro growth inhibition (GIT tests. The immunization schedule was based on two 1.0 mL doses of non-diluted formalininactivated whole culture bacterin given through subcutaneous route with 10-day interval. The challenge was performed ten days after the second vaccine dose, when the animals were inoculated with 0.2 mL of non-inactivated cultures of each serovar through intraperitoneal route. On the 21st post-challenge day (PCD, all animals were bled and their sera were joined in pools (n=8 and tested by MAT and GIT. All vaccinated and control animals presented no clinical signs of leptospirosis after the challenge, but the serovar guaricura was isolated from the kidneys of control animals on the 21st PCD. The MAT results showed cross agglutinins between serovars hardjo and wolffi, and between wolffi and guaricura. The GIT results revealed the presence of cross neutralizing antibodies between serovars wolffi or guaricura against hardjo, wolffi and guaricura. It was found that the tested strain of serovar hardjo did not produce detectable levels of neutralizing antibodies, indicating its poor immunogenicity.

In Vivo Transfer and Microevolution of Avian Native IncA/C2blaNDM-1-Carrying Plasmid pRH-1238 during a Broiler Chicken Infection Study.

Science.gov (United States)

Hadziabdic, Sead; Fischer, Jennie; Malorny, Burkhard; Borowiak, Maria; Guerra, Beatriz; Kaesbohrer, Annemarie; Gonzalez-Zorn, Bruno; Szabo, Istvan

2018-04-01

The emergence and spread of carbapenemase-producing Enterobacteriaceae (CPE) in wildlife and livestock animals pose an important safety concern for public health. With our in vivo broiler chicken infection study, we investigated the transfer and experimental microevolution of the bla NDM-1 -carrying IncA/C 2 plasmid (pRH-1238) introduced by avian native Salmonella enterica subsp. enterica serovar Corvallis without inducing antibiotic selection pressure. We evaluated the dependency of the time point of inoculation on donor ( S Corvallis [12-SA01738]) and plasmid-free Salmonella recipient [d-tartrate-fermenting (d-Ta + ) S Paratyphi B (13-SA01617), referred to here as S Paratyphi B (d-Ta + )] excretion by quantifying their excretion dynamics. Using plasmid profiling by S1 nuclease-restricted pulsed-field gel electrophoresis, we gained insight into the variability of the native plasmid content among S Corvallis reisolates as well as plasmid acquisition in S Paratyphi B (d-Ta + ) and the enterobacterial gut microflora. Whole-genome sequencing enabled us to gain an in-depth insight into the microevolution of plasmid pRH-1238 in S Corvallis and enterobacterial recipient isolates. Our study revealed that the fecal excretion of avian native carbapenemase-producing S Corvallis is significantly higher than that of S Paratyphi (d-Ta + ) and is not hampered by S Paratyphi (d-Ta + ). Acquisition of pRH-1238 in other Enterobacteriaceae and several events of plasmid pRH-1238 transfer to different Escherichia coli sequence types and Klebsiella pneumoniae demonstrated an interspecies broad host range. Regardless of the microevolutionary structural deletions in pRH-1238, the single carbapenem resistance marker bla NDM-1 was maintained on pRH-1238 throughout the trial. Furthermore, we showed the importance of the gut E. coli population as a vector of pRH-1238. In a potential scenario of the introduction of NDM-1-producing S Corvallis into a broiler flock, the pRH-1238 plasmid could

Draft Genome Sequence of Leptospira interrogans Serovar Bataviae Strain LepIMR 22 Isolated from a Rodent in Johor, Malaysia.

Science.gov (United States)

Amran, Fairuz; Mohd Khalid, Mohd Khairul Nizam; Mohamad, Saharuddin; Mat Ripen, Adiratna; Ahmad, Norazah; Goris, Marga G A; Muhammad, Ayu Haslin; Noor Halim, Nurul Atiqah

2016-09-08

Leptospira interrogans serovar Bataviae was recently identified as one of the persistent Leptospira serovars in Malaysia. Here, we report the draft genome sequence of the L. interrogans serovar Bataviae strain LepIMR 22 isolated from kidney of a rodent in Johor, Malaysia. Copyright © 2016 Amran et al.

Rickettsia typhi in rodents and R. felis in fleas in Yucatán as a possible causal agent of undefined febrile cases.

Science.gov (United States)

Peniche-Lara, Gaspar; Dzul-Rosado, Karla; Pérez-Osorio, Carlos; Zavala-Castro, Jorge

2015-01-01

Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study's results contributed to a better knowledge of Rickettsia epidemiology in Yucatán.

Assessment of exposure to Leptospira serovars in veterinary staff and dog owners in contact with infected dogs.

Science.gov (United States)

Barmettler, Reto; Schweighauser, Ariane; Bigler, Susanne; Grooters, Amy M; Francey, Thierry

2011-01-15

To assess patterns of seroreactivity to Leptospira serovars in veterinary professional staff and dog owners exposed to dogs with acute leptospirosis and to contrast these patterns in people with those observed in dogs. Cross-sectional study. Human subjects consisted of 91 people (50 veterinarians, 19 technical staff, 9 administrative personnel, and 13 dog owners) exposed to dogs with leptospirosis. Canine subjects consisted of 52 dogs with naturally occurring leptospirosis admitted to the University of Bern Vetsuisse Faculty Small Animal Clinic in 2007 and 2008. People were tested for seroreactivity to regionally prevalent Leptospira serovars by use of a complement fixation test. A questionnaire designed to identify risk factors associated with seropositivity was used to collect demographic information from each study participant. Dogs were tested for seroreactivity to Leptospira serovars by use of a microscopic agglutination test. On the basis of microscopic agglutination test results, infected dogs were seropositive for antibodies against Leptospira serovars as follows (in descending order): Bratislava (43/52 [83%]), Australis (43/52 [83%]), Grippotyphosa (18/52 [35%]), Pomona (12/52 [23%]), Autumnalis (6/52 [12%]), Icterohemorrhagiae (4/52 [8%]), Tarassovi (2/52 [4%]), and Canicola (1/52 [2%]). All 91 people were seronegative for antibodies against Leptospira serovars. Therefore, statistical evaluation of risk factors and comparison of patterns of seroreactivity to Leptospira serovars between human and canine subjects were limited to theoretical risks. Seroreactivity to Leptospira serovars among veterinary staff adhering to standard hygiene protocols and pet owners exposed to dogs with acute leptospirosis was uncommon.

Repeated isolation of Salmonella enterica Goverdhan, a very rare serovar, from Danish poultry surveillance samples

DEFF Research Database (Denmark)

Pedersen, Karl; Sørensen, Gitte; Szabo, Istvan

2014-01-01

We report here the appearance of a very rare serovar of Salmonella, S. enterica subsp. enterica serovar Goverdhan, in routine Salmonella surveillance samples from Danish poultry production. S. Goverdhan was found on nine occasions: in one broiler breeder farm in October 2010, four broiler farms a...

A defective mutant of Salmonella enterica Serovar Gallinarum in cobalamin biosynthesis is avirulent in chickens Mutante de Salmonella enterica serovar Gallinarum duplo defectivo na biossíntese de cobalamina é avirulento para aves

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Jacqueline Boldrin de Paiva

2009-09-01

Full Text Available Salmonella enterica serovar Gallinarum (SG is a fowl typhoid agent in chickens and is a severe disease with worldwide economic impact as its mortality may reach up to 80%. It is one of a small group of serovars that typically produces typhoid-like infections in a narrow range of host species and which therefore represents a good model for human typhoid. The survival mechanisms are not considered to be virulent mechanisms but are essential for the life of the bacterium. Mutants of Salmonella Gallinarum containing defective genes, related to cobalamin biosynthesis and which Salmonella spp. has to be produced to survive when it is in an anaerobic environment, were produced in this study. Salmonella Gallinarum is an intracellular parasite. Therefore, this study could provide information about whether vitamin B12 biosynthesis might be essential to its survival in the host. The results showed that the singular deletion in cbiA or cobS genes did not interfere in the life of Salmonella Gallinarum in the host, perhaps because single deletion is not enough to impede vitamin B12 biosynthesis. It was noticed that diluted SG mutants with single deletion produced higher mortality than the wild strain of SG. When double mutation was carried out, the Salmonella Gallinarum mutant was unable to provoke mortality in susceptible chickens. This work showed that B12 biosynthesis is a very important step in the metabolism of Salmonella Gallinarum during the infection of the chickens. Further research on bacterium physiology should be carried out to elucidate the events described in this research and to assess the mutant as a vaccine strain.Salmonella enterica serovar Gallinarum (SG é o agente do tifo aviário, doença severa que provoca mortalidade em até 80% do plantel de aves. SG encontra-se entre os poucos sorotipos de Salmonella que são agentes etiológicos de enfermidade específica, à semelhança de Salmonella Typhi em seres humanos podendo, portanto, servir

Characterization of multidrug-resistant Salmonella enterica serovars Indiana and Enteritidis from chickens in Eastern China.

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Yan Lu

Full Text Available A total of 310 Salmonella isolates were isolated from 6 broiler farms in Eastern China, serotyped according to the Kauffmann-White classification. All isolates were examined for susceptibility to 17 commonly used antimicrobial agents, representative isolates were examined for resistance genes and class I integrons using PCR technology. Clonality was determined by pulsed-field gel electrophoresis (PFGE. There were two serotypes detected in the 310 Salmonella strains, which included 133 Salmonella enterica serovar Indiana isolates and 177 Salmonella enterica serovar Enteritidis isolates. Antimicrobial sensitivity results showed that the isolates were generally resistant to sulfamethoxazole, ampicillin, tetracycline, doxycycline and trimethoprim, and 95% of the isolates sensitive to amikacin and polymyxin. Among all Salmonella enterica serovar Indiana isolates, 108 (81.2% possessed the blaTEM, floR, tetA, strA and aac (6'-Ib-cr resistance genes. The detected carriage rate of class 1 integrons was 66.5% (206/310, with 6 strains carrying gene integron cassette dfr17-aadA5. The increasing frequency of multidrug resistance rate in Salmonella was associated with increasing prevalence of int1 genes (rs = 0.938, P = 0.00039. The int1, blaTEM, floR, tetA, strA and aac (6'-Ib-cr positive Salmonella enterica serovar Indiana isolates showed five major patterns as determined by PFGE. Most isolates exhibited the common PFGE patterns found from the chicken farms, suggesting that many multidrug-resistant isolates of Salmonella enterica serovar Indiana prevailed in these sources. Some isolates with similar antimicrobial resistance patterns represented a variety of Salmonella enterica serovar Indiana genotypes, and were derived from a different clone.

Removal of salmonella-typhi, shigella-dysenteriae, vibrio-cholerae and rotavirus from water using a water-treatment tablet

CSIR Research Space (South Africa)

Rodda, N

1993-01-01

Full Text Available previously demonstrated. This study evaluated the efficiency of removal of Salmonella typhi, Shigella dysenteriae, Vibrio cholerae and rotavirus from simulated hard water of high organic content and colour. All four pathogenic micro organisms were...

Isolasi karakterisasi dan pengelompokan strain Salmonella typhi asal Kabupaten Sumba Barat Daya Nusa Tenggara Timur berdasarkan sifat-sifat fenotip

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Charis Amarantini

2012-02-01

Full Text Available Typhoid fever is highly endemic in the South-West Sumba Regency, East Nusa Tenggara. The incidence rate of the diseases is high estimated at 725/100,000. It is an acute systemic infection caused by Salmonella typhi. The clinical symptoms of the disease are extremely diverse, starting from the mild form to severe ones with the most feared complication being perforation within the small intestine. Therefore, it is important to perform isolation, characterization, and grouping of S. typhi strains from the blood culture in order to determined definitely diagnosis and the different phenotypic characteristics in the community. Isolation was done in selective and differential media: BacT/ALERT FA culture media, Selenite Cystine Broth, Chromocult Coliform Agar, MacConkey Agar, andSalmonella Shigella Agar. The typical colony of Salmonella was confirmed on Triple Sugar Iron Agar, Urea agar, and L-Lysinedecarboxylation media. Phenotypic characteristics of all isolates were identified using API 20E and API 50CHE diagnostics. Based on biochemical characteristics the result showed that 18 strains obtained from different geographical origins were diverse. Four strains have similarity value 100% while the remained strains have similarity value 86.3-98.4%. All of the strains were categorized in the species of S. typhi.

Prevalence, serovars and antimicrobial susceptibility of Salmonella spp. from wild and domestic green iguanas (Iguana iguana) in Grenada, West Indies.

Science.gov (United States)

Sylvester, W R B; Amadi, V; Pinckney, R; Macpherson, C N L; McKibben, J S; Bruhl-Day, R; Johnson, R; Hariharan, H

2014-09-01

Cloacal swabs from 62 green iguanas (Iguana iguana), including 47 wild and 15 domestic ones from five parishes of Grenada, were sampled during a 4-month period of January to April 2013 and examined by enrichment and selective culture for the presence of Salmonella spp. Fifty-five per cent of the animals were positive, and eight serovars of Salmonella were isolated. The most common serovar was Rubislaw (58.8%), a serovar found recently in many cane toads in Grenada, followed by Oranienburg (14.7%), a serovar that has been causing serious human disease outbreaks in Japan. Serovar IV:48:g,z51 :- (formerly, S. Marina) highly invasive and known for serious infections in children in the United States, constituted 11.8% of the isolates, all of them being from domestic green iguanas. Salmonella Newport, a serovar recently found in a blue land crab in Grenada, comprised 11.8% of the isolates from the green iguanas. The remaining four less frequent serovars included S. Javiana and S. Glostrup. Antimicrobial susceptibility tests conducted by a disc diffusion method against amoxicillin-clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, nalidixic acid, streptomycin, tetracycline and trimethoprim-sulfamethoxazole showed that drug resistance is minimal, with intermediate susceptibility, mainly to streptomycin, tetracycline and cefotaxime. This is the first report of isolation and antimicrobial susceptibilities of various Salmonella serovars from wild and domestic green iguanas in Grenada, West Indies. © 2013 Blackwell Verlag GmbH.

Leptospira Serovars for Diagnosis of Leptospirosis in Humans and Animals in Africa: Common Leptospira Isolates and Reservoir Hosts.

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Mgode, Georgies F; Machang'u, Robert S; Mhamphi, Ginethon G; Katakweba, Abdul; Mulungu, Loth S; Durnez, Lies; Leirs, Herwig; Hartskeerl, Rudy A; Belmain, Steven R

2015-12-01

The burden of leptospirosis in humans and animals in Africa is higher than that reported from other parts of the world. However, the disease is not routinely diagnosed in the continent. One of major factors limiting diagnosis is the poor availability of live isolates of locally circulating Leptospira serovars for inclusion in the antigen panel of the gold standard microscopic agglutination test (MAT) for detecting antibodies against leptospirosis. To gain insight in Leptospira serovars and their natural hosts occurring in Tanzania, concomitantly enabling the improvement of the MAT by inclusion of fresh local isolates, a total of 52 Leptospira isolates were obtained from fresh urine and kidney homogenates, collected between 1996 and 2006 from small mammals, cattle and pigs. Isolates were identified by serogrouping, cross agglutination absorption test (CAAT), and molecular typing. Common Leptospira serovars with their respective animal hosts were: Sokoine (cattle and rodents); Kenya (rodents and shrews); Mwogolo (rodents); Lora (rodents); Qunjian (rodent); serogroup Grippotyphosa (cattle); and an unknown serogroup from pigs. Inclusion of local serovars particularly serovar Sokoine in MAT revealed a 10-fold increase in leptospirosis prevalence in Tanzania from 1.9% to 16.9% in rodents and 0.26% to 10.75% in humans. This indicates that local serovars are useful for diagnosis of human and animal leptospirosis in Tanzania and other African countries.

Expression of hilA in response to mild acid stress in Salmonella enterica is serovar and strain dependent.

Science.gov (United States)

González-Gil, Francisco; Le Bolloch, Alexandre; Pendleton, Sean; Zhang, Nan; Wallis, Audra; Hanning, Irene

2012-05-01

Salmonella enterica is the leading cause of foodborne illness with poultry and poultry products being primary sources of infection. The 2 most common S. enterica serovars associated with human infection are Typhimurium and Enteritidis. However, Kentucky and Heidelburg and the 2 most prevalent serovars isolated from poultry environments. Given the prevalence of other serovars in poultry products and environments, research is needed to understand virulence modulation in response to stress in serovars other than Typhimurium and Enteritidis. Thus, the objective of this research was to compare hilA gene expression (a master regulator of the virulence pathogenicity island) in response to acid stress among different strains and serovars of Salmonella. A total of 11 serovars consisting of 15 strains of S. enterica were utilized for these experiments. Cultures were suspended in tryptic soy broth (TSB) adjusted to pH 7.2, 6.2, or 5.5 with HCl or acetic acid. Total RNA was extracted from cultures at specific time points (0, 2, 4, and 24 h). Gene expression of hilA was measured with quantitative reverse transcriptase real time PCR (qRT-PCR). Growth and pH were measured throughout the 24 h time frame. Regulation of hilA in response to acid stress varied by serovar and strain and type of acid. The results of these experiments indicate that hilA regulation may have some impact on virulence and colonization of S. enterica. However, these results warrant further research to more fully understand the significance of hilA regulation in response to mild acid stress in S. enterica. © 2012 Institute of Food Technologists®

Molecular Characterization of Multidrug-Resistant Salmonella enterica subsp. enterica Serovar Typhimurium Isolates from Swine

OpenAIRE

Gebreyes, Wondwossen Abebe; Altier, Craig

2002-01-01

As part of a longitudinal study of antimicrobial resistance among salmonellae isolated from swine, we studied 484 Salmonella enterica subsp. enterica serovar Typhimurium (including serovar Typhimurium var. Copenhagen) isolates. We found two common pentaresistant phenotypes. The first was resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (the AmCmStSuTe phenotype; 36.2% of all isolates), mainly of the definitive type 104 (DT104) phage type (180 of 187 ...

Polyamines are essential for virulence in Salmonella enterica serovar Gallinarum despite evolutionary decay of polyamine biosynthesis genes

DEFF Research Database (Denmark)

Schroll, Casper; Christensen, Jens P.; Christensen, Henrik

2014-01-01

. Typhi and S. Gallinarum and happened through independent events. The remaining polyamine biosynthesis pathway was found to be essential for oral infection with S. Gallinarum since single and double mutants in speB and speE, encoding the pathways from agmatine to putrescine and from putrescine...... to putrescine. The first pathway is not active in S. Gallinarum and S. Typhi, and this prompted us to investigate the importance of polyamines for virulence in S. Gallinarum. Bioinformatic analysis of all sequenced genomes of Salmonella revealed that pseudogene formation of the speC gene was exclusive for S...

Rapidly changing treatment options adding burden to the management of typhoid fever

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Jaspal Kaur

2015-01-01

Full Text Available Typhoid fever continues to be a global public health problem. It is caused by the facultative intracellular organisms Salmonella enteric serotype Typhi and Salmonella paratyphi. Antimicrobial therapy is the mainstay for treatment of typhoid fever. Chloramphenicol, ampicillin, and cotrimoxazole had been in use for decades for treating enteric fever. But the emergence and rapid spread of drug resistance has resulted in rapid shift of treatment options from chloramphenicol to fluoroquinolones to third generation cephalosporins to azithromycin with tigecycline and carbapenems in line, thus adding burden to the health-care sector in developing countries. Rational and judicious antibiotic prescribing practices by health professionals are necessary to prevent further development of drug resistance and help in re-emergence of sensitive strains.

Bacterial genotoxin functions as immune-modulator and promotes host survival

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Riccardo Guidi

2016-07-01

Full Text Available Bacterial genotoxins are effectors that cause DNA damage in target cells. Many aspects of the biology of these toxins have been characterised in vitro, such as structure, cellular internalisation pathways and effects on the target cells. However, little is known about their function in vivo. Salmonella enterica serovar Typhi (S. Typhi is a Gram-negative, intracellular bacterium that causes typhoid fever, a debilitating disease infecting more than 20 million people every year. S. Typhi produce a genotoxin named typhoid toxin (TT, but its role in the contest of host infection is poorly characterized. The major obstacle in addressing this issue is that S. Typhi is exclusively a human pathogen. To overcome this limitation, we have used as model bacterium S. Typhimurium, and engineered it to produce endogenous levels of an active and inactive typhoid toxin, hereby named as TT (or genotoxic and cdtB (or control, respectively. To our surprise, infection with the genotoxin strain strongly suppressed intestinal inflammation, leading to a better survival of the host during the acute phase of infection, suggesting typhoid toxin may exert a protective role. The presence of a functional genotoxin was also associated with an increased frequency of asymptomatic carriers.

Typhoid fever cases in the U.S. military.

Science.gov (United States)

Sorrell, Tia; Selig, Daniel J; Riddle, Mark S; Porter, Chad K

2015-10-14

Salmonella enterica, serovar Typhi (S. Typhi), a causative agent of enteric fever (typhoid fever), predominately affects populations in developing regions with poor access to clean food and water. In addition, travelers to these regions are at risk of exposure. We report the epidemiological characteristics of S. Typhi cases among active duty United States military personnel from 1998 to 2011 using data obtained from the Defense Medical Surveillance System. Cases were identified based on International Classification for Disease Ninth Edition - Clinical Modification codes. We identified a total of 205 cases S. Typhi for an incidence of 1.09 per 100,000 person-years. Cases were on average 31.7 years old, predominately married (n = 129, 62.9 %), Caucasian (n = 142, 69.3 %), male (n = 176, 85.9 %), and had a high school education (n = 101, 49.3 %). Of the identified cases, 122 had received a Typhoid vaccination within 4 years of diagnosis. This study provides an overview of enteric fever in the United States military. The incidence was similar to the general U.S. population except for increased incidence from 1998 to 2000, perhaps attributable to operational deployments in that period. Given that vaccination is an effective primary prevention measure against typhoid fever, active monitoring of pre-deployment vaccine history is warranted.

Rhabdomyolysis Complicating Typhoid Fever in A Child and Review of the Literature.

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Snelling, Peter James; Moriarty, Paul; Vaska, Vikram L; Levitt, David; Nourse, Clare

2017-09-01

Typhoid fever is an important cause of morbidity and mortality in the developing world, particularly in children, but is infrequently observed in the developed world and can occur in patients without a significant travel history. Rhabdomyolysis as a complication has rarely been reported, and never in a child. A child with Salmonella enterica serovar Typhi septicemia, complicated by rhabdomyolysis, encephalopathy and pancreatitis is described and all 15 reported cases to date are summarized.

Human migration is important in the international spread of exotic Salmonella serovars in animal and human populations.

Science.gov (United States)

Iveson, J B; Bradshaw, S D; How, R A; Smith, D W

2014-11-01

The exposure of indigenous humans and native fauna in Australia and the Wallacea zoogeographical region of Indonesia to exotic Salmonella serovars commenced during the colonial period and has accelerated with urbanization and international travel. In this study, the distribution and prevalence of exotic Salmonella serovars are mapped to assess the extent to which introduced infections are invading native wildlife in areas of high natural biodiversity under threat from expanding human activity. The major exotic Salmonella serovars, Bovismorbificans, Derby, Javiana, Newport, Panama, Saintpaul and Typhimurium, isolated from wildlife on populated coastal islands in southern temperate areas of Western Australia, were mostly absent from reptiles and native mammals in less populated tropical areas of the state. They were also not recorded on the uninhabited Mitchell Plateau or islands of the Bonaparte Archipelago, adjacent to south-eastern Indonesia. Exotic serovars were, however, isolated in wildlife on 14/17 islands sampled in the Wallacea region of Indonesia and several islands off the west coast of Perth. Increases in international tourism, involving islands such as Bali, have resulted in the isolation of a high proportion of exotic serovar infections suggesting that densely populated island resorts in the Asian region are acting as staging posts for the interchange of Salmonella infections between tropical and temperate regions.

Isolation of Leptospira santarosai, serovar guaricura from buffaloes (Bubalus bubalis in Vale do Ribeira, São Paulo, Brazil

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Vasconcellos Silvio A.

2001-01-01

Full Text Available In April 1998 urine samples from adult female buffaloes were collected in a farm located in Registro, Vale do Ribeira, São Paulo State, Brazil. The urine samples obtained after furosemide injection were immediately transported to the laboratory in liquid modified EMJH medium and seeded, by the serial dilution technique, into Fletcher's or modified EMJH-0.2% agar, both of them with 5-fluorouracil 100mg/mL. The intraperitoneoum inoculation of 0.5 mL was also performed with each urine sample in young, adult hamsters (Mesocricetus auratus. All samples seeded directly in culture medium were contaminated. The hamsters did not show any sign of disease and were killed at the 21st post inoculation day. At this time kidney cultures of these animals were performed and from one of them, one leptospira strain (M04-98 was isolated, identified as belonging to serogroup Sejroe by Microscopic Agglutination Test (MAT with a panel of 36 rabbit sera against serovars representative for the pathogenic serogroups. Subsequently, MAT was carried out with antisera against the 19 reference strains of serogroup Sejroe, revealing a close relationship with serovar guaricura. Afterwards the MAT was done with a panel of 18 monoclonal antibodies representative for serovars of serogroup Sejroe. The histogram closely resembled that of serovar guaricura. So Cross Agglutination Absorption Test (CAAT was carried out with the buffalo isolate and serovar guaricura, supporting the relationship between the buffalo isolate and serovar guaricura.

Rapid Detection of Chlamydia trachomatis and Typing of the Lymphogranuloma venereum associated L-Serovars by TaqMan PCR

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Henrich Birgit

2008-04-01

Full Text Available Abstract Background Infection due to Chlamydia trachomatis is the most common sexually transmitted bacterial disease of global health significance, and especially the L-serovars causing lymphogranuloma venereum are increasingly being found in Europe in men who have sex with men. Results The design and evaluation of a rapid, multiplex, real-time PCR targeting the major outer membrane protein (omp-1 -gene and a L-serovar-specific region of the polymorphic protein H (pmp-H -gene for the detection of Chlamydia trachomatis is reported here. The PCR takes place as a single reaction with an internal control. For L1-, L2- and L3-serovar differentiation a second set of real-time PCRs was evaluated based on the amplification of serovar-specific omp-1-regions. The detection limit of each real-time PCR, multiplexed or not, was 50 genome copies per reaction with an efficiency ranging from 90,5–95,2%. In a retrospective analysis of 50 ocular, rectal and urogenital specimens formerly tested to be positive for C. trachomatis we identified six L2-serovars in rectal specimens of HIV-positive men, one in a double-infection with L3, and one L2 in a urethral specimen of an HIV-negative male. Conclusion This unique real-time PCR is specific and convenient for the rapid routine-diagnostic detection of lymphogranuloma venereum-associated L-serovars and enables the subsequent differentiation of L1, L2 and L3 for epidemiologic studies.

Rapid Detection of Chlamydia trachomatis and Typing of the Lymphogranuloma venereum associated L-Serovars by TaqMan PCR

Science.gov (United States)

Schaeffer, Anke; Henrich, Birgit

2008-01-01

Background Infection due to Chlamydia trachomatis is the most common sexually transmitted bacterial disease of global health significance, and especially the L-serovars causing lymphogranuloma venereum are increasingly being found in Europe in men who have sex with men. Results The design and evaluation of a rapid, multiplex, real-time PCR targeting the major outer membrane protein (omp-1) -gene and a L-serovar-specific region of the polymorphic protein H (pmp-H) -gene for the detection of Chlamydia trachomatis is reported here. The PCR takes place as a single reaction with an internal control. For L1-, L2- and L3-serovar differentiation a second set of real-time PCRs was evaluated based on the amplification of serovar-specific omp-1-regions. The detection limit of each real-time PCR, multiplexed or not, was 50 genome copies per reaction with an efficiency ranging from 90,5–95,2%. In a retrospective analysis of 50 ocular, rectal and urogenital specimens formerly tested to be positive for C. trachomatis we identified six L2-serovars in rectal specimens of HIV-positive men, one in a double-infection with L3, and one L2 in a urethral specimen of an HIV-negative male. Conclusion This unique real-time PCR is specific and convenient for the rapid routine-diagnostic detection of lymphogranuloma venereum-associated L-serovars and enables the subsequent differentiation of L1, L2 and L3 for epidemiologic studies. PMID:18447917

Rapid Determination of Lymphogranuloma Venereum Serovars of Chlamydia trachomatis by Quantitative High-Resolution Melt Analysis (HRMA)

Science.gov (United States)

Stevens, Matthew P.; Garland, Suzanne M.; Zaia, Angelo M.; Tabrizi, Sepehr N.

2012-01-01

A quantitative high-resolution melt analysis assay was developed to differentiate lymphogranuloma venereum-causing serovars of Chlamydia trachomatis (L1 to L3) from other C. trachomatis serovars (D to K). The detection limit of this assay is approximately 10 copies per reaction, comparable to the limits of other quantitative-PCR-based methods. PMID:22933594

Chlamydia trachomatis Serovar Distribution and Neisseria gonorrhoeae Coinfection in Male Patients with Urethritis in Greece▿

Science.gov (United States)

Papadogeorgakis, Helen; Pittaras, Theodore E.; Papaparaskevas, Joseph; Pitiriga, Vassiliki; Katsambas, Andreas; Tsakris, Athanassios

2010-01-01

The distribution of Chlamydia trachomatis serovars and Neisseria gonorrhoeae coinfection was studied in a group of 100 C. trachomatis-positive males with urethritis in Greece. The serovar distribution revealed that apart from the predominant worldwide types E and F, the relatively uncommon type G is also prevalent. Gonococcal coinfection was frequent (30%) and was associated with genovariant Ja (75%, P = 0.008). PMID:20357220

Gel-chromatographic and light scattering study of the salmonella typhi endotoxin

Energy Technology Data Exchange (ETDEWEB)

Dezhelici, G; Dezhelici, N; Jusici, D [Zagreb Univ. (Yugoslavia)

1977-01-01

The endotoxin of Salmonella typhi, strain 0-901 extracted with 1 M sodium chloride was studied by gel-chromatography and light scattering. The extracted material consisted of two components: a high molecular weight endotoxin (5.6 milion dalton) and a lower molecular weight protein-polysaccharide complex (less than 66,000 dalton). The endotoxin component proved to be a highly polydispersed material. Estimation of various averages of gyration radii suggested a more compact structure of endotoxin particles than those obtained by the Boivin extraction method, possibly due to the tertiary structuring of polypeptide chains in the protein-lipopolysaccharide complex of the endotoxin particle.

Vaccination with leptospiral outer membrane lipoprotein LipL32 reduces kidney invasion of Leptospira interrogans serovar canicola in hamsters.

Science.gov (United States)

Humphryes, P C; Weeks, M E; AbuOun, M; Thomson, G; Núñez, A; Coldham, N G

2014-04-01

The Leptospira interrogans vaccines currently available are serovar specific and require regular booster immunizations to maintain protection of the host. In addition, a hamster challenge batch potency test is necessary to evaluate these vaccines prior to market release, requiring the use of a large number of animals, which is ethically and financially undesirable. Our previous work showed that the N terminus of the outer membrane protein LipL32 was altered in Leptospira interrogans serovar Canicola vaccines that fail the hamster challenge test, suggesting that it may be involved in the protective immune response. The aim of this study was to determine if vaccination with LipL32 protein alone could provide a protective response against challenge with L. interrogans serovar Canicola to hamsters. Recombinant LipL32, purified from an Escherichia coli expression system, was assessed for protective immunity in five groups of hamsters (n = 5) following a challenge with the virulent L. interrogans serovar Canicola strain Kito as a challenge strain. However, no significant survival against the L. interrogans serovar Canicola challenge was observed compared to that of unvaccinated negative controls. Subsequent histological analysis revealed reduced amounts of L. interrogans in the kidneys from the hamsters vaccinated with recombinant LipL32 protein prior to challenge; however, no significant survival against the L. interrogans serovar Canicola challenge was observed compared to that of unvaccinated negative controls. This finding corresponded to a noticeably reduced severity of renal lesions. This study provides evidence that LipL32 is involved in the protective response against L. interrogans serovar Canicola in hamsters and is the first reported link to LipL32-induced protection against kidney invasion.

Salmonella Typhi Colonization Provokes Extensive Transcriptional Changes Aimed at Evading Host Mucosal Immune Defense During Early Infection of Human Intestinal Tissue

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K.P. Nickerson

2018-05-01

Full Text Available Commensal microorganisms influence a variety of host functions in the gut, including immune response, glucose homeostasis, metabolic pathways and oxidative stress, among others. This study describes how Salmonella Typhi, the pathogen responsible for typhoid fever, uses similar strategies to escape immune defense responses and survive within its human host. To elucidate the early mechanisms of typhoid fever, we performed studies using healthy human intestinal tissue samples and “mini-guts,” organoids grown from intestinal tissue taken from biopsy specimens. We analyzed gene expression changes in human intestinal specimens and bacterial cells both separately and after colonization. Our results showed mechanistic strategies that S. Typhi uses to rearrange the cellular machinery of the host cytoskeleton to successfully invade the intestinal epithelium, promote polarized cytokine release and evade immune system activation by downregulating genes involved in antigen sampling and presentation during infection. This work adds novel information regarding S. Typhi infection pathogenesis in humans, by replicating work shown in traditional cell models, and providing new data that can be applied to future vaccine development strategies. Keywords: Typhoid fever, Salmonella, Snapwell™ system, Human tissue, Terminal ileum, Immune system, Innate immunity, Immune evasion, Host-pathogen interaction, Vaccine development, Intestinal organoids, Organoid monolayer

A Leptospira borgpetersenii Serovar Hardjo vaccine induces a Th1 response, activates NK cells, and reduces renal colonization

Science.gov (United States)

Chronic infection of cattle with Leptospira borgpetersenii serovar Hardjo reduces animal production through reproductive failure and presents a persistent health threat to workers in the animal industry. Cattle are maintenance hosts for serovar Hardjo and development of a protective vaccine has bee...

Alteration in transforming growth factor-β receptor expression in gallbladder disease: implications of chronic cholelithiasis and chronic Salmonella typhi infection

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Yogesh D. Walawalkar

2016-08-01

Full Text Available Gallbladder cancer prevalence is ever increasing with Salmonella typhi chronic infection being one of the predisposing factors. Altered ratios or expression of transforming growth factor-β (TGF-β receptors and changes in its function are associated with loss in anti-proliferative effects of TGF-β and cancer progression. Using reverse transcriptase polymerase chain reaction we monitor any changes in TGF-β receptor gene expression. We simultaneously screen for S. typhi within the samples. From 73 patients undergoing cholecystectomy 39-50% had significant expression (P<0.05 of TGF-β receptor (TβR- I and TβR-II during chronic cholelithiasis as compared to the remaining 19-23% with acute chronic cholelithiasis. There was no significant increase in TβR-III receptor expression. Patient’s positive for S. typhi (7/73 did not show any significant changes in expression of these receptors, thus indicating no direct relation in regulating the host TGFβ-signaling pathway. Further analysis on expression of downstream Smad components revealed that patients with up-regulated TGFβ receptor expression show >2-fold increase in the RSmads and Co-Smads with a >2-fold decrease in I-Smads. Thus gain of TβR-I and II expression in epithelial cells of the gallbladder was associated with chronic inflammatory stages of the gallbladder disease.

Molecular epidemiology of fluoroquinolone resistant Salmonella in Africa: A systematic review and meta-analysis.

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Tadesse, Getachew; Tessema, Tesfaye S; Beyene, Getenet; Aseffa, Abraham

2018-01-01

Wide-ranging evidence on the occurrence of fluoroquinolone (FQ) resistance genetic determinants in African Salmonella strains is not available. The main objectives of this study were to assess the heterogeneity, estimate pooled proportions and describe the preponderance of FQ-resistance determinants in typhoidal and non-typhoidal Salmonella (NTS) isolates of Africa. Genetic and phenotypic data on 6103 Salmonella isolates were considered. Meta- and frequency analyses were performed depending on the number of studies by category, number of isolates and risks of bias. A random effects model was used to assess heterogeneity and estimate pooled proportions. Relative and cumulative frequencies were calculated to describe the overall preponderance of FQ-resistance determinants in quinolone resistant isolates. The pooled proportion of gyrA mutants (Salmonella enterica serovar Typhi, Salmonella enterica serovar Typhimurium, and Salmonella enterica serovar Enteritidis) was estimated at 5.7% (95% Confidence interval (CI) = 2.6, 9.8; Tau squared (T2) = 0.1105), and was higher in S. Typhi than in S. Typhimurium (odds ratio (OR) = 3.3, 95%CI = 2, 5.7). The proportions of each of gyrB and parC mutants, and strains with Plasmid Mediated Quinolone Resistance genes (qnrA, qnrB and qnrS) were low (≤ 0.3%). Overall, 23 mutant serotypes were identified, and most strains had mutations at codons encoding Ser83 and Asp87 of gyrA (82%, 95%CI = 78, 86). Mutations at gyrA appear to account for ciprofloxacin non-susceptibility in most clinical Salmonella strains in Africa. The estimates could be harnessed to develop a mismatch-amplification mutation-assay for the detection of FQ-resistant strains in Africa.

Listeria prevalence and Listeria monocytogenes serovar diversity at cull cow and bull processing plants in the United States.

Science.gov (United States)

Guerini, Michael N; Brichta-Harhay, Dayna M; Shackelford, T Steven D; Arthur, Terrance M; Bosilevac, Joseph M; Kalchayanand, Norasak; Wheeler, Tommy L; Koohmaraie, Mohammad

2007-11-01

Listeria monocytogenes, the causative agent of epidemic and sporadic listeriosis, is routinely isolated from many sources, including cattle, yet information on the prevalence of Listeria in beef processing plants in the United States is minimal. From July 2005 through April 2006, four commercial cow and bull processing plants were sampled in the United States to determine the prevalence of Listeria and the serovar diversity of L. monocytogenes. Samples were collected during the summer, fall, winter, and spring. Listeria prevalence on hides was consistently higher during cooler weather (28 to 92% of samples) than during warmer weather (6 and 77% of samples). The Listeria prevalence data collected from preevisceration carcass ranged from undetectable in some warm season samples to as high as 71% during cooler weather. Listeria on postintervention carcasses in the chill cooler was normally undetectable, with the exception of summer and spring samples from one plant where > 19% of the carcasses were positive for Listeria. On hides, L. monocytogenes serovar 1/2a was the predominant serovar observed, with serovars 1/2b and 4b present 2.5 times less often and serovar 1/2c not detected on any hides sampled. L. monocytogenes serovars 1/2a, 1/2c, and 4b were found on postintervention carcasses. This prevalence study demonstrates that Listeria species are more prevalent on hides during the winter and spring and that interventions being used in cow and bull processing plants appear to be effective in reducing or eliminating Listeria contamination on carcasses.

Functional assay of Salmonella typhi OmpC using reconstituted large unilamellar vesicles: a general method for characterization of outer membrane proteins.

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Sundara Baalaji, N; Mathew, M K; Krishnaswamy, S

2006-10-01

The immunodominant trimeric beta-barrel outer membrane protein OmpC from Salmonella typhi, the causative agent of typhoid, has been functionally characterized here. The activity in the vesicle environment was studied in vitro using OmpC reconstituted into proteoliposomes. Passage of polysaccharides and polyethyleneglycols through OmpC has been examined to determine the permeability properties. The relative rate of neutral solute flux yields a radius of 1.1 nm for the S. typhi OmpC pore. This is almost double the pore size of Escherichia coli. This provides an example of large pore size present in the porins that form trimers as in the general bacterial porin family. The method used in this study provides a good membrane model for functional studies of porins.

Global monitoring of Salmonella serovar distribution from the World Health Organization Global Foodborne Infections Network Country Data Bank: results of quality assured laboratories from 2001 to 2007.

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Hendriksen, Rene S; Vieira, Antonio R; Karlsmose, Susanne; Lo Fo Wong, Danilo M A; Jensen, Arne B; Wegener, Henrik C; Aarestrup, Frank M

2011-08-01

Salmonella enterica is commonly acquired from contaminated food and is an important cause of illness worldwide. Interventions are needed to control Salmonella; subtyping Salmonella by serotyping is useful for targeting such interventions. We, therefore, analyzed the global distribution of the 15 most frequently identified serovars of Salmonella isolated from humans from 2001 to 2007 in laboratories from 37 countries that participated in World Health Organization Global Foodborne Infections Network and demonstrated serotyping proficiency in the Global Foodborne Infections Network External Quality Assurance System. In all regions throughout the study period, with the exception of the Oceania and North American regions, Salmonella serovars Enteritidis and Typhimurium ranked as the most common and second most common serovar, respectively. In the North American and Oceania (Australia and New Zealand) regions, Salmonella serovar Typhimurium was the most common serovar reported, and Salmonella serovar Enteritidis was the second most common serovar. During the study period, the proportion of Salmonella isolates reported from humans that were Salmonella serovar Enteritidis was 43.5% (range: 40.6% [2007] to 44.9% [2003]), and Salmonella serovar Typhimurium was 17.1% (range: 15% [2007] to 18.9% [2001]). Salmonella serovars Newport (mainly observed in Latin and North American and European countries), Infantis (dominating in all regions), Virchow (mainly observed in Asian, European, and Oceanic countries), Hadar (profound in European countries), and Agona (intense in Latin and North American and European countries) were also frequently isolated with an overall proportion of 3.5%, 1.8%, 1.5%, 1.5%, and 0.8%, respectively. There were large differences in the most commonly isolated serovars between regions, but lesser differences between countries within the same region. The results also highlight the complexity of the global epidemiology of Salmonella and the need and importance

High prevalence of Rickettsia typhi and Bartonella species in rats and fleas, Kisangani, Democratic Republic of the Congo

NARCIS (Netherlands)

Laudisoit, A.; Falay, D.; Amundala, N.; de Bellock, J.G.; van Houtte, N.; Breno, M.; Verheven, E.; Wilschut, Liesbeth; Parola, P.; Raoult, D.; C., Socolovschi

2014-01-01

The prevalence and identity of Rickettsia and Bartonella in urban rat and flea populations were evaluated in Kisangani, Democratic Republic of the Congo (DRC) by molecular tools. An overall prevalence of 17% Bartonella species and 13% Rickettsia typhi, the agent of murine typhus, was found in the

Structural basis of typhod: Salmonella typhi type IVb pilin (PilS) and cystic fibrosis transmembrane conductance regulator interaction

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Balakrishna, A.; Saxena, A; Mok, H; Swaminathan, K

2009-01-01

The type IVb pilus of the enteropathogenic bacteria Salmonella typhi is a major adhesion factor during the entry of this pathogen into gastrointestinal epithelial cells. Its target of adhesion is a stretch of 10 residues from the first extracellular domain of cystic fibrosis transmembrane conductance regulator (CFTR). The crystal structure of the N-terminal 25 amino acid deleted S. typhi native PilS protein (PilS), which makes the pilus, was determined at 1.9 A resolution by the multiwavelength anomalous dispersion method. Also, the structure of the complex of PilS and a target CFTR peptide, determined at 1.8 A, confirms that residues 113-117 (NKEER) of CFTR are involved in binding with the pilin protein and gives us insight on the amino acids that are essential for binding. Furthermore, we have also explored the role of a conserved disulfide bridge in pilus formation. The subunit structure and assembly architecture are crucial for understanding pilus functions and designing suitable therapeutics against typhoid.

Structural basis of typhoid: Salmonella typhi type IVb pilin (PiLS) and cystic fibrosis transmembrane conductance regulator interaction

Energy Technology Data Exchange (ETDEWEB)

Balakrishna, A.M.; Saxena, A.; Mok, H. Y.-K.; Swaminathan, K.

2009-11-01

The type IVb pilus of the enteropathogenic bacteria Salmonella typhi is a major adhesion factor during the entry of this pathogen into gastrointestinal epithelial cells. Its target of adhesion is a stretch of 10 residues from the first extracellular domain of cystic fibrosis transmembrane conductance regulator (CFTR). The crystal structure of the N-terminal 25 amino acid deleted S. typhi native PilS protein ({Delta}PilS), which makes the pilus, was determined at 1.9 {angstrom} resolution by the multiwavelength anomalous dispersion method. Also, the structure of the complex of {Delta}PilS and a target CFTR peptide, determined at 1.8 {angstrom}, confirms that residues 113-117 (NKEER) of CFTR are involved in binding with the pilin protein and gives us insight on the amino acids that are essential for binding. Furthermore, we have also explored the role of a conserved disulfide bridge in pilus formation. The subunit structure and assembly architecture are crucial for understanding pilus functions and designing suitable therapeutics against typhoid.

Structural Basis of Typhoid: Salmonella typhi Type IVb pilin (PilS) and Cystic Fibrosis Transmembrane Conductance Regulatory Interaction

Energy Technology Data Exchange (ETDEWEB)

Balakrishna, A.; Saxena, A; Mok, H; Swaminathan, K

2009-01-01

The type IVb pilus of the enteropathogenic bacteria Salmonella typhi is a major adhesion factor during the entry of this pathogen into gastrointestinal epithelial cells. Its target of adhesion is a stretch of 10 residues from the first extracellular domain of cystic fibrosis transmembrane conductance regulator (CFTR). The crystal structure of the N-terminal 25 amino acid deleted S. typhi native PilS protein (PilS), which makes the pilus, was determined at 1.9 A resolution by the multiwavelength anomalous dispersion method. Also, the structure of the complex of PilS and a target CFTR peptide, determined at 1.8 A, confirms that residues 113-117 (NKEER) of CFTR are involved in binding with the pilin protein and gives us insight on the amino acids that are essential for binding. Furthermore, we have also explored the role of a conserved disulfide bridge in pilus formation. The subunit structure and assembly architecture are crucial for understanding pilus functions and designing suitable therapeutics against typhoid.

Molecular typing of Salmonella typhi strains from Dhaka (Bangladesh) and development of DNA probes identifying plasmid-encoded multidrug-resistant isolates

NARCIS (Netherlands)

P.W.M. Hermans (Peter); S.K. Saha; W.J. van Leeuwen (Wibeke); H.A. Verbrugh (Henri); A.F. van Belkum (Alex); W.H.F. Goessens (Wil)

1996-01-01

textabstractSeventy-eight Salmonella typhi strains isolated in 1994 and 1995 from patients living in Dhaka, Bangladesh, were subjected to phage typing, ribotyping, IS200 fingerprinting, and PCR fingerprinting. The collection displayed a high degree of genetic

Enhanced detection rate of typhoid fever among clinically suspected patients in a tertiary referral hospital in Dhaka, Bangladesh using nested polymerase chain reaction technology.

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Khan, S; Miah, M R; Khatun, S

2015-12-01

A nested polymerase chain reaction (PCR) specific for Salmonella enterica subspecies enteric serovar Typhi was used for the detection of the pathogen, in blood. This study was done during the period of March 2013 to February 2014. A total of 80 clinically suspected cases of typhoid fever were included in the study. Blood was collected from all participating individuals. Nested PCR targeting the flagellin gene (fliC) of Salmonella Typhi & blood culture were done for each of the cases. The positivity rate of PCR & blood culture was 70%& 20% respectively. The positivity rate of PCR was significantly higher than blood culture (Ptyphoid fever cases on the basis of clinical features but with negative cultures. We conclude that the PCR technique could be used as a novel diagnostic method of typhoid fever, particularly in culture-negative cases in an endemic country like Bangladesh.

Effects of propolis from Brazil and Bulgaria on Salmonella serovars

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R. O. Orsi

2007-01-01

Full Text Available Propolis shows biological properties such as antibacterial action. This bee product has a complex chemical composition, which depends on the local flora where it is produced. Salmonella serovars are responsible for human diseases that range from localized gastroenteritis to systemic infections. The aim of the present study was to investigate the susceptibility of Salmonella strains, isolated from food and infectious processes, to the antibacterial action of Brazilian and Bulgarian propolis, as well as to determine the behavior of these bacteria, according to the incubation period, in medium plus propolis. Dilution of ethanolic extract of propolis in agar was the used method. Brazilian and Bulgarian propolis showed an antibacterial action against all Salmonella serovars. The minimal inhibitory concentrations (MIC of propolis were similar, although they were collected in different geographic regions. Salmonella typhimurium, isolated from human infection, was more resistant to propolis than Salmonella enteritidis.

Multidrug-Resistant Salmonella enterica Serovar Muenchen from Pigs and Humans and Potential Interserovar Transfer of Antimicrobial Resistance

OpenAIRE

Gebreyes, Wondwossen A.; Thakur, Siddhartha

2005-01-01

Salmonella serovars are important reservoirs of antimicrobial resistance. Recently, we reported on multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium strains among pigs with resistance to ampicillin, kanamycin, streptomycin, sulfamethoxazole, and tetracycline (resistance [R] type AKSSuT) and resistance to amoxicillin-clavulanic acid, ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (R type AxACSSuT). In the present study, 67 isolates (39 from humans...

Salmonella enterica Serovar Typhimurium and Escherichia coli Contamination of Root and Leaf Vegetables Grown in Soils with Incorporated Bovine Manure

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Natvig, Erin E.; Ingham, Steven C.; Ingham, Barbara H.; Cooperband, Leslie R.; Roper, Teryl R.

2002-01-01

Bovine manure, with or without added Salmonella enterica serovar Typhimurium (three strains), was incorporated into silty clay loam (SCL) and loamy sand (LS) soil beds (53- by 114-cm surface area, 17.5 cm deep) and maintained in two controlled-environment chambers. The S. enterica serovar Typhimurium inoculum was 4 to 5 log CFU/g in manure-fertilized soil. The conditions in the two environmental chambers, each containing inoculated and uninoculated beds of manure-fertilized soil, simulated daily average Madison, Wis., weather conditions (hourly temperatures, rainfall, daylight, and humidity) for a 1 March or a 1 June manure application and subsequent vegetable growing seasons ending 9 August or 28 September, respectively. Core soil samples were taken biweekly from both inoculated and uninoculated soil beds in each chamber. Radishes, arugula, and carrots were planted in soil beds, thinned, and harvested. Soils, thinned vegetables, and harvested vegetables were analyzed for S. enterica serovar Typhimurium and Escherichia coli (indigenous in manure). After the 1 March manure application, S. enterica serovar Typhimurium was detected at low levels in both soils on 31 May, but not on vegetables planted 1 May and harvested 12 July from either soil. After the 1 June manure application, S. enterica serovar Typhimurium was detected in SCL soil on 7 September and on radishes and arugula planted in SCL soil on 15 August and harvested on 27 September. In LS soil, S. enterica serovar Typhimurium died at a similar rate (P ≥ 0.05) after the 1 June manure application and was less often detected on arugula and radishes harvested from this soil compared to the SCL soil. Pathogen levels on vegetables were decreased by washing. Manure application in cool (daily average maximum temperature of vegetables are not contaminated with S. enterica serovar Typhimurium. Manure application under warmer (daily average maximum temperature >20°C) summer conditions is not recommended when

Leptospira santorosai Serovar Shermani detergent extract induces an increase in fibronectin production through a Toll-like receptor 2-mediated pathway.

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Tian, Ya-Chung; Hung, Cheng-Chieh; Li, Yi-Jung; Chen, Yung-Chang; Chang, Ming-Yang; Yen, Tzung-Hai; Hsu, Hsiang-Hao; Wu, Mai-Szu; Phillips, Aled; Yang, Chih-Wei

2011-03-01

Leptospirosis can activate inflammatory responses through Toll-like receptors (TLRs) and may cause renal tubulointerstitial fibrosis characterized by the accumulation of extracellular matrix (ECM). We have previously demonstrated that Leptospira santorosai serovar Shermani detergent extract stimulates ECM accumulation in vitro. The aim of this study was to examine the mechanistic basis of these previous observations and, in particular, to examine the potential involvement of TLRs. The addition of serovar Shermani detergent extract led to an increase in fibronectin gene expression and production. Inhibition of TLR2 but not TLR4 expression abrogated serovar Shermani detergent extract-mediated increases in fibronectin production. This response was also blocked by the knockdown of the gene expression of the TLR2 downstream transducers myeloid differentiation factor 88 (MyD88) and tumor necrosis factor receptor-associated factor 6 (TRAF6). Serovar Shermani detergent extract also activated nuclear factor-κB, and its inhibition by curcumin-attenuated serovar Shermani detergent extract induced increases in fibronectin production. These effects were also mimicked by the specific TLR2 agonist, Pam(3)CsK(4), a response that was also abrogated by the knockdown of MyD88 and TRAF6. Similarly, the administration of live leptospires to cells also induced fibronectin production that was blocked by inhibition of TLR2 and MyD88 expression. In conclusion, serovar Shermani detergent extract can induce fibronectin production through the TLR2-associated cascade, providing evidence of an association between TLRs and leptospirosis-mediated ECM deposition.

DNA biosensor for detection of Salmonella typhi from blood sample of typhoid fever patient using gold electrode modified by self-assembled monolayers of thiols

Science.gov (United States)

Suryapratiwi, Windha Novita; Paat, Vlagia Indira; Gaffar, Shabarni; Hartati, Yeni Wahyuni

2017-05-01

Electrochemical biosensors are currently being developed in order to handle various clinical problems in diagnosing infectious diseases caused by pathogenic bacteria, or viruses. On this research, voltammetric DNA biosensor using gold electrode modified by thiols with self-assembled monolayers had been developed to detect a certain sequence of Salmonella typhi DNA from blood sample of typhoid fever patient. Thiol groups of cysteamines (Cys) and aldehyde groups from glutaraldehydes (Glu) were used as a link to increase the performance of gold electrode in detecting guanine oxidation signal of hybridized S. typhi DNA and ssDNA probe. Standard calibration method was used to determine analytical parameters from the measurements. The result shown that, the detection of S. typhi DNA from blood sample of typhoid fever patient can be carried out by voltammetry using gold electrode modified by self-assembled monolayers of thiols. A characteristic oxidation potential of guanine using Au/Cys/Gluwas obtained at +0.17 until +0.20 V. Limit of detection and limit of quantification from this measurements were 1.91μg mL-1 and 6.35 μg mL-1. The concentration of complement DNA from sample was 6.96 μg mL-1.

Molecular identification of the ompL1 gene within Leptospira interrogans standard serovars.

Science.gov (United States)

Dezhbord, Mehrangiz; Esmaelizad, Majid; Khaki, Pejvak; Fotohi, Fariba; Zarehparvar Moghaddam, Athena

2014-06-11

Leptospirosis, caused by infection with pathogenic Leptospira species, is one of the most prevalent zoonotic diseases in the world. Current leptospiral vaccines are mainly multivalent dead whole-cell mixtures made of several local dominant serovars. Therefore, design and construction of an efficient recombinant vaccine for leptospirosis control is very important. OmpL1 is an immunogenic porin protein that could be of special significance in vaccination and serodiagnosis for leptospirosis. Three strains belonging to pathogenic L. interrogans were analyzed. The specific primers for proliferation of the ompL1 gene were designed. The amplified gene was cloned. In order to investigate the ompL1 nucleotide sequence and homological analysis of this gene, ompL1 genes cloned from standard vaccinal Leptospira serovars prevalent in Iran were sequenced and cloned. PCR amplification of the ompL1 gene using the designed primers resulted in a 963 bp ompL1 gene product. The PCR based on the ompL1 gene detected all pathogenic reference serovars of Leptospira spp. tested. Based on alignment and phylogenetic analysis, although the ompL1 nucleotide sequence was slightly different within three vaccinal serovars (100%-85% identity), amino acid alignment of the OmpL1 proteins revealed that there would be inconsiderable difference among them. The ompL1 gene of the three isolates was well conserved, differing only by a total of 6 bp and the proteins by 2 amino acids. The cloned gene could be further used for expression and recombinant OmpL1 as an efficient and conserved antigen, and may be a useful vaccine candidate against leptospirosis in our region.

Detección molecular de Rickettsia typhi en perros de una comunidad rural de Yucatán, México

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Daly Martínez-Ortiz

2016-04-01

Conclusión. Se detectó la presencia de R. typhi pero una baja frecuencia de infección en perros de la comunidad de estudio; sin embargo, la especie podría representar un riesgo de transmisión para los seres humanos.

Early diagnosis of typhoid fever by nested PCR for flagellin gene of Salmonella enterica serotype Typhi.

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Khan, S; Harish, B N; Menezes, G A; Acharya, N S; Parija, S C

2012-11-01

Typhoid fever caused by Salmonella Typhi continues to be a major health problem in spite of the use of antibiotics and the development of newer antibacterial drugs. Inability to make an early laboratory diagnosis and resort to empirical therapy, often lead to increased morbidity and mortality in cases of typhoid fever. This study was aimed to optimize a nested PCR for early diagnosis of typhoid fever and using it as a diagnostic tool in culture negative cases of suspected typhoid fever. Eighty patients with clinical diagnosis of typhoid fever and 40 controls were included in the study. The blood samples collected were subjected to culture, Widal and nested PCR targeting the flagellin gene of S. Typhi. The sensitivity of PCR on blood was found to be 100 per cent whereas the specificity was 76.9 per cent. The positive predictive value (PPV) of PCR was calculated to be 76.9 per cent with an accuracy of 86 per cent. None of the 40 control samples gave a positive PCR. Due to its high sensitivity and specificity nested PCR can be used as a useful tool to diagnose clinically suspected, culture negative cases of typhoid fever.

Research note: Molecular subtyping of Salmonella enterica serovar Tshiongwe recently isolated in Malaysia during 2001-2002.

Science.gov (United States)

Thong, Kwai Lin; Bakeri, Shamsilawani Ahmad; Lai, Kin Seng; Koh, Yin Tee; Taib, Mohd Zainuldin; Lim, V K E; Yasin, Rohani Md

2004-03-01

Pulsed field gel electrophoresis (PFGE) and antimicrobial susceptibility analysis were undertaken on twenty-three strains of Salmonella enterica serovar Tshiongwe, an unusual serovar, which recently emerged in Malaysia. Antimicrobial susceptibility analysis showed that all the strains were sensitive to ampicilin, chloramphenicol, cotrimoxazole, and kanamycin. Twenty (87%) and 8 (3.5%) strains had resistance to tetracycline and streptomycin respectively. PFGE analysis subtyped 23 strains into 10 profiles (Dice coefficient of similarity, F = 0.7-1.0). The predominant profile, X1 was found in both clinical and environmental isolates and was widely distributed in different parts of Malaysia during the study period. In addition, isolates recovered from food, a hand-towel, apron and the surface of a table-top in one particular location had unique, indistinguishable profiles (X4/4a) and identical antibiograms. Similarly, isolates from cooked meat and a chopping board had PFGE profiles similar to some human isolates. These probably indicated cross-contamination and poor hygiene in food practices, hence contributing to Salmonellosis. Factors causing the emergence of this rare Salmonella serovar being responsible for food poisoning episodes during the study period remained unclear. The study reiterated the usefulness and versatility of PFGE in the molecular subtyping of this rare Salmonella serovar in Malaysia.

Method for the detection of Salmonella enterica serovar Enteritidis

Science.gov (United States)

Agron, Peter G.; Andersen, Gary L.; Walker, Richard L.

2008-10-28

Described herein is the identification of a novel Salmonella enterica serovar Enteritidis locus that serves as a marker for DNA-based identification of this bacterium. In addition, three primer pairs derived from this locus that may be used in a nucleotide detection method to detect the presence of the bacterium are also disclosed herein.

Same species, different diseases: how and why typhoidal and non-typhoidal Salmonella enterica serovars differ

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Ohad eGal-Mor

2014-08-01

Full Text Available Human infections by the bacterial pathogen Salmonella enterica represent major disease burdens worldwide. This highly ubiquitous species consists of more than 2600 different serovars that can be divided into typhoidal and non-typhoidal Salmonella (NTS serovars. Despite their genetic similarity, these two groups elicit very different diseases and distinct immune responses in humans. Comparative analyses of the genomes of multiple Salmonella serovars have begun to explain the basis of the variation in disease manifestations. Recent advances in modeling both enteric fever and intestinal gastroenteritis in mice will facilitate investigation into both the bacterial- and host-mediated mechanisms involved in salmonelloses. Understanding the genetic and molecular mechanisms responsible for differences in disease outcome will augment our understanding of Salmonella pathogenesis, host immunity, and the molecular basis of host specificity. This review outlines the differences in epidemiology, clinical manifestations, and the human immune response to typhoidal and NTS infections and summarizes the current thinking on why these differences might exist.

Colicinogeny in Salmonella serovars isolated in Brazil

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Leila Carvalho Campos

1988-06-01

Full Text Available A study of colicinogeny was made in 748 strains of Salmonella (97 serovars isolated from different sources; human (291, animal (119, environmental (141, food (102 and animal feed (95. Colicin production was detected in 64 strains (8.6%, particularly isolated from foods (30.4%. Col. E1 (53 and Ia (44 were the most frequently observed, especially in S. agona for environment and food sources. Col V production was identified in 5 strains of S. typhimurium within 8 producer cultures isolated from humans. Its relationship with the sources and serovars of Salmonella are discussed.Investigou-se a produção de colicina em 748 amostras de Salmonella (97 sorovares advindas de díferentes fontes: humana (291, animal (119, ambiental (141, de alimentos (102 e rações (95. Detectaram-se 64 amostras (8,6% colicinogênicas, particularmente isoladas de alimentos (30,4%. ColE1 (53 e Ia (44 foram as mais freqüentes, especialmente no sorovar S, agona, de origem ambiental e de alimentos. Identificou-se também a produção de col V em 5 amostras de S. typhimurium dentre 8 culturas produtoras de origem humana. Discute-se a relação entre a capacidade colicinogênica e as fontes e sorovares de Salmonella.

Human leptospirosis: occurrence of serovars of Leptospira spp. in the state of Minas Gerais, Brazil, from 2008 to 2012.

Science.gov (United States)

Oliveira, Marluce Aparecida Assunção; Leal, Élida Aparecida; Correia, Max Assunção; Serufo Filho, José Carlos; Dias, Ricardo Souza; Serufo, José Carlos

Leptospirosis is an infectious and acute disease caused by Leptospira spp. that have high epidemic potential. This study verified the main Leptospira spp. serovars detected by MAT from serum of patients with suspicion of leptospirosis from 2008 to 2012 in Minas Gerais State. The laboratory received sera from 4654 patients. All serum were screened by IgM-ELISA according to the manufacturer's instructions. Each sample reactive or indeterminate were tested against twenty-four serovars of Leptospira by MAT. In this study, 597 patients were classified as reactive on MAT. Only 301 patients were confirmed by laboratory test. It was not possible confirmation by laboratory diagnosis of 296 patients. Among the samples classified as reactive on MAT, 273 patients exhibited titers bigger than 800 for one or more serovars; seroconversion was detected in 28 cases. Percentage of 85.1% of the samples reactive on MAT corresponded to males, 39.4% corresponded to patients aged between 20 and 39 years old. The most common serovars found were Icterohaemorrhagiae, Andamana, Patoc, Tarassovi, Copenhageni, Hardjo and Australis. Concerning the samples that exhibited titers bigger than 800, serovar Icterohaemorrhagiae was also the most common, followed by Copenhageni, Andamana, Patoc, Tarassovi, Grippotyphosa and Canicola. In this study, 40% of the cases occurred to the metropolitan area, state capital and 34 neighboring towns. Our results show the possibly spreading serovars in Minas Gerais State and contribute to knowledge of human leptospirosis, aiming at improving the prevention, control of the disease, as well as the treatment of infected patients. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Prevalence and antimicrobial resistance of Salmonella serovars isolated from poultry in Ghana

DEFF Research Database (Denmark)

Andoh, Linda A.; Dalsgaard, Anders; Obiri-Danso, K.

2016-01-01

Poultry are possible sources of non-typhoidal Salmonella serovars which may cause foodborne human disease. We conducted a cross-sectional study to determine the prevalence of Salmonella serovars in egg-laying hens and broilers at the farm level and their susceptibility to antimicrobials commonly...... of antimicrobials). Of the resistant strains (n = 57), the most significant were to nalidixic acid (89·5%), tetracycline (80·7%), ciprofloxacin (64·9%), sulfamethazole (42·1%), trimethoprim (29·8%) and ampicillin (26·3%). All S. Kentucky strains were resistant to more than two antimicrobials and shared common...

Horizontal gene transfer of a ColV plasmid has resulted in a dominant avian clonal type of Salmonella enterica serovar Kentucky.

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Timothy J Johnson

Full Text Available Salmonella enterica continues to be a significant cause of foodborne gastrointestinal illness in humans. A wide variety of Salmonella serovars have been isolated from production birds and from retail poultry meat. Recently, though, S. enterica subsp. enterica serovar Kentucky has emerged as one of the prominent Salmonella serovars isolated from broiler chickens. Recent work suggests that its emergence apparently coincides with its acquisition of a ColV virulence plasmid. In the present study, we examined 902 Salmonella isolates belonging to 59 different serovars for the presence of this plasmid. Of the serovars examined, the ColV plasmid was found only among isolates belonging to the serovars Kentucky (72.9%, Typhimurium (15.0% and Heidelberg (1.7%. We demonstrated that a single PFGE clonal type of S. Kentucky harbors this plasmid, and acquisition of this plasmid by S. Kentucky significantly increased its ability to colonize the chicken cecum and cause extraintestinal disease. Comparison of the completed sequences of three ColV plasmids from S. Kentucky isolated from different geographical locales, timepoints and sources revealed a nearly identical genetic structure with few single nucleotide changes or insertions/deletions. Overall, it appears that the ColV plasmid was recently acquired by a single clonal type S. Kentucky and confers to its host enhanced colonization and fitness capabilities. Thus, the potential for horizontal gene transfer of virulence and fitness factors to Salmonella from other enteric bacteria exists in poultry, representing a potential human health hazard.

Evaluation of the use of selective PCR amplification of LPS biosynthesis genes for molecular typing of leptospira at the serovar level

NARCIS (Netherlands)

Bezerra da Silva, Josefa; Carvalho, Eneas; Hartskeerl, Rudy A.; Ho, Paulo L.

2011-01-01

Leptospirosis is an important epidemic zoonosis worldwide. Currently, there are more than 250 Leptospira pathogenic serovars known that can potentially infect humans. Conventional classification of leptospires with the serovar as the basic taxon, based on serological recognition of

New Leptospira serovar Sokoine of serogroup Icterohaemorrhagiae from cattle in Tanzania

NARCIS (Netherlands)

Mgode, G. F.; Machang'u, R. S.; Goris, M. G.; Engelbert, M.; Sondij, S.; Hartskeerl, R. A.

2006-01-01

The prevalence of leptospirosis is generally high in domestic animals and rodents in Tanzania. Identification of Leptospira isolates from cattle was carried out to establish prevalent Leptospira serovars. Serological typing was done based on monoclonal antibodies and the standard cross-agglutination

Systemic and Terminal Ileum Mucosal Immunity Elicited by Oral Immunization With the Ty21a Typhoid Vaccine in HumansSummary

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Jayaum S. Booth

2017-11-01

Full Text Available Background & Aims: Systemic cellular immunity elicited by the Ty21a oral typhoid vaccine has been extensively characterized. However, very limited data are available in humans regarding mucosal immunity at the site of infection (terminal ileum [TI]. Here we investigated the host immunity elicited by Ty21a immunization on terminal ileum–lamina propria mononuclear cells (LPMC and peripheral blood in volunteers undergoing routine colonoscopy. Methods: We characterized LPMC-T memory (TM subsets and assessed Salmonella enterica serovar Typhi (S Typhi–specific responses by multichromatic flow cytometry. Results: No differences were observed in cell yields and phenotypes in LPMC CD8+-TM subsets following Ty21a immunization. However, Ty21a immunization elicited LPMC CD8+ T cells exhibiting significant S Typhi–specific responses (interferon-γ, tumor necrosis factor-α, interleukin-17A, and/or CD107a in all major TM subsets (T-effector/memory [TEM], T-central/memory, and TEM-CD45RA+, although each TM subset exhibited unique characteristics. We also investigated whether Ty21a immunization elicited S Typhi–specific multifunctional effectors in LPMC CD8+ TEM. We observed that LPMC CD8+ TEM responses were mostly multifunctional, except for those cells exhibiting the characteristics associated with cytotoxic responses. Finally, we compared mucosal with systemic responses and made the important observation that LPMC CD8+ S Typhi–specific responses were unique and distinct from their systemic counterparts. Conclusions: This study provides the first demonstration of S Typhi–specific responses in the human terminal ileum mucosa and provides novel insights into the generation of mucosal immune responses following oral Ty21a immunization. Keywords: Lamina Propria Mononuclear Cells, Multifunctional T Cells, CD8+-T Memory Cells, Typhoid, Vaccines

Cytotoxic effector functions of T cells are not required for protective immunity against fatal Rickettsia typhi infection in a murine model of infection: Role of TH1 and TH17 cytokines in protection and pathology.

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Kristin Moderzynski

2017-02-01

Full Text Available Endemic typhus caused by Rickettsia (R. typhi is an emerging febrile disease that can be fatal due to multiple organ pathology. Here we analyzed the requirements for protection against R. typhi by T cells in the CB17 SCID model of infection. BALB/c wild-type mice generate CD4+ TH1 and cytotoxic CD8+ T cells both of which are sporadically reactivated in persistent infection. Either adoptively transferred CD8+ or CD4+ T cells protected R. typhi-infected CB17 SCID mice from death and provided long-term control. CD8+ T cells lacking either IFNγ or Perforin were still protective, demonstrating that the cytotoxic function of CD8+ T cells is not essential for protection. Immune wild-type CD4+ T cells produced high amounts of IFNγ, induced the release of nitric oxide in R. typhi-infected macrophages and inhibited bacterial growth in vitro via IFNγ and TNFα. However, adoptive transfer of CD4+IFNγ-/- T cells still protected 30-90% of R. typhi-infected CB17 SCID mice. These cells acquired a TH17 phenotype, producing high amounts of IL-17A and IL-22 in addition to TNFα, and inhibited bacterial growth in vitro. Surprisingly, the neutralization of either TNFα or IL-17A in CD4+IFNγ-/- T cell recipient mice did not alter bacterial elimination by these cells in vivo, led to faster recovery and enhanced survival compared to isotype-treated animals. Thus, collectively these data show that although CD4+ TH1 cells are clearly efficient in protection against R. typhi, CD4+ TH17 cells are similarly protective if the harmful effects of combined production of TNFα and IL-17A can be inhibited.

Host-Nonspecific Iron Acquisition Systems and Virulence in the Zoonotic Serovar of Vibrio vulnificus

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Pajuelo, David; Lee, Chung-Te; Roig, Francisco J.; Lemos, Manuel L.; Hor, Lien-I

2014-01-01

The zoonotic serovar of Vibrio vulnificus (known as biotype 2 serovar E) is the etiological agent of human and fish vibriosis. The aim of the present work was to discover the role of the vulnibactin- and hemin-dependent iron acquisition systems in the pathogenicity of this zoonotic serovar under the hypothesis that both are host-nonspecific virulence factors. To this end, we selected three genes for three outer membrane receptors (vuuA, a receptor for ferric vulnibactin, and hupA and hutR, two hemin receptors), obtained single and multiple mutants as well as complemented strains, and tested them in a series of in vitro and in vivo assays, using eels and mice as animal models. The overall results confirm that hupA and vuuA, but not hutR, are host-nonspecific virulence genes and suggest that a third undescribed host-specific plasmid-encoded system could also be used by the zoonotic serovar in fish. hupA and vuuA were expressed in the internal organs of the animals in the first 24 h of infection, suggesting that they may be needed to achieve the population size required to trigger fatal septicemia. vuuA and hupA were sequenced in strains representative of the genetic diversity of this species, and their phylogenies were reconstructed by multilocus sequence analysis of selected housekeeping and virulence genes as a reference. Given the overall results, we suggest that both genes might form part of the core genes essential not only for disease development but also for the survival of this species in its natural reservoir, the aquatic environment. PMID:24478087

Characterization of Leptospira santarosai Serogroup Grippotyphosa Serovar Bananal Isolated from Capybara ( Hydrochaeris hydrochaeris ) in Brazil.

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Moreno, Luisa Z; Miraglia, Fabiana; Marvulo, Maria F V; Silva, Jean C R; Paula, Catia D; Costa, Barbara L P; Morais, Zenaide M; Ferreira, Fernando; Neto, José S Ferreira; Dellagostin, Odir A; Hartskeerl, Rudy A; Vasconcellos, Silvio A; Moreno, Andrea M

2016-07-01

Leptospirosis is a widespread zoonosis caused by bacteria of the genus Leptospira. Rodents appear to be the most important reservoirs of infection. They contaminate the environment and food and can transmit the pathogen when they are consumed by carnivores. Capybara ( Hydrochaeris hydrochaeris ) are efficient reservoirs of Leptospira, and because they are in close contact with farm animals and are found in semiurban areas, they represent a risk to public health. We isolated five Leptospira strains from capybara kidneys in Sao Paulo State, Brazil, in 2001 and typed them using serologic and molecular techniques. These strains include the Leptospira santarosai serogroup Grippotyphosa serovar Bananal. Pulsed field gel electrophoresis resulted in a unique pattern distinct from the reference strains, and the isolates clustered with greater than 85% similarity. The isolates also presented higher growth rates than other Leptospira serovars, with high minimal inhibitory concentration values for most of the tested antibiotics, with the exception of penicillin and ampicillin. This isolation and characterization of the L. santarosai serogroup Grippotyphosa serovar Bananal from capybara, highlights the importance of wild and sinantropic rodents as carriers of pathogenic leptospires.

Prevalence and characterization of multi-drug resistant Salmonella Enterica serovar Gallinarum biovar Pullorum and Gallinarum from chicken

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Md. Shafiullah Parvej

2016-01-01

Full Text Available Aim: Salmonella is an important zoonotic pathogen responsible for animal and human diseases. The aim of the present study was to determine the prevalence and stereotyping of Salmonella isolates isolated from apparently healthy poultry. Furthermore, the clonal relatedness among the isolated Salmonella serovars was assessed. Materials and Methods: A total of 150 cloacal swab samples from apparently healthy chickens were collected, and were subjected for the isolation and identification of associated Salmonella organisms. The isolated colonies were identified and characterized on the basis of morphology, cultural characters, biochemical tests, slide agglutination test, polymerase chain reaction, and pulsed-field gel electrophoresis (PFGE. Antibiotic sensitivity patterns were also investigated using commonly used antibiotics. Results: Of the 150 samples, 11 (7.33% produced characteristics pink colony with black center on XLD agar medium, and all were culturally and biochemically confirmed to be Salmonella. All possessed serovar-specific gene SpeF and reacted uniformly with group D antisera, suggesting that all of the isolates were Salmonella Enterica serovar Gallinarum, biovar Pullorum and/or Gallinarum. Antimicrobial susceptibility testing revealed that 54.54% of the isolated Salmonella Enterica serovars were highly sensitive to ciprofloxacin, whereas the 81.81% isolates were resistant to amoxycillin, doxycycline, kanamycin, gentamycin, and tetracycline. Pulsed-field gel electrophoresis of the XbaI-digested genomic DNA exhibited identical banding patterns, suggesting that the multidrug resistant Salmonella Enterica serovars occurring in commercial layers are highly clonal in Bangladesh. Conclusion: The present study was conducted to find out the prevalence of poultry Salmonella in layer chicken and to find out the clonal relationship among them. The data in this study suggest the prevalence of Salmonella Enterica, which is multidrug resistant and

Antibacterial and antifungal screening of the root extracts of nardostachys jatamansi

International Nuclear Information System (INIS)

Sohail, T.; Yaqeen, Z.; Imran, H.; Shaukat, S.

2007-01-01

Antimicrobial activity of ethanol, ethyl acetate and hexane extracts of Nardostachys roots were studied in vitro against six pathogenic gram positive bacteria (Stayphylococcus aureus, streptococcus intermedius, S. faecalis, Bacillus Pumilus, B. cereus B. subtilus), six gram negative bacteria (Escherichia coli, Salmonella typhi, S. Paratyphi B, Klebsiella Pneumoniae, Proteus mirabilus, Shigella flexneri) and five fungi (Trichophyton rubrum, T. schoenleinii, Aspergillus niger, Candida albicans, C. glabrata). Ethanolic root extract exhibited maximum antimicrobial activity against all the tested bacteria and gungi, at concentration of 5, 10 and 20 mg/ml as compared to ethyl acetate and hexane extract, which did not show marked activity. Antimicrobial activity was compared with the activities of standard antibacterial and antifungal drugs, namely Ampicillin and Nystatin, respectively. The minimum inhibitory concentration (MIC) were between 0.5-1 mg/ml against all the studied microorganisms. (author)

ramR Mutations Affecting Fluoroquinolone Susceptibility in Epidemic Multidrug-Resistant Salmonella enterica Serovar Kentucky ST198

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Axel eCloeckaert

2013-07-01

Full Text Available A screening for non-target mutations affecting fluoroquinolone susceptibility was conducted in epidemic multidrug-resistant Salmonella enterica serovar Kentucky ST198. Among a panel of representative isolates (n=30, covering the epidemic, only three showed distinct mutations in ramR resulting in enhanced expression of genes encoding the AcrAB-TolC efflux system and low increase in ciprofloxacin MIC. No mutations were detected in other regulatory regions of this efflux system. Ciprofloxacin resistance in serovar Kentucky ST198 is thus currently mainly due to multiple target gene mutations.

Prevalence and characterization of Salmonella serovars isolated from oysters served raw in restaurants.

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Brillhart, Crystal D; Joens, Lynn A

2011-06-01

To determine if Salmonella-contaminated oysters are reaching consumer tables, a survey of raw oysters served in eight Tucson restaurants was performed from October 2007 to September 2008. Salmonella spp. were isolated during 7 of the 8 months surveyed and were present in 1.2% of 2,281 oysters tested. This observed prevalence is lower than that seen in a previous study in which U.S. market oysters were purchased from producers at bays where oysters are harvested. To test whether the process of refrigerating oysters in restaurants for several days reduces Salmonella levels, oysters were artificially infected with Salmonella and kept at 4°C for up to 13 days. Direct plate counts of oyster homogenate showed that Salmonella levels within oysters did not decrease during refrigeration. Six different serovars of Salmonella enterica were found in the restaurant oysters, indicating multiple incidences of Salmonella contamination of U.S. oyster stocks. Of the 28 contaminated oysters, 12 (43%) contained a strain of S. enterica serovar Newport that matched by pulsed-field gel electrophoresis a serovar Newport strain seen predominantly in the study of bay oysters performed in 2002. The repeated occurrence of this strain in oyster surveys is concerning, since the strain was resistant to seven antimicrobials tested and thus presents a possible health risk to consumers of raw oysters.

POTENSI Salmonella typhi YANG DILEMAHKAN DENGAN SINAR ULTRAVIOLET SEBAGAI VAKSIN ALTERNATIF

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Andreas Putro Ragil Santoso

2016-03-01

Full Text Available Salmonella typhi is a Gram-negative intracellular bacterium and causes typhoid fever in humans. The success rate of Berma Vivotif Ty21a vaccine in Indonesia is only 33-66%, while in other countries have been reached up to 100%. The research was conducted in order to determine the potency of local isolate bacteria to stimulate the immune response and the impact of different exposure frequencies on the immune response and the different immune response time when administered by UV-inactivated vaccine.. The results showed that the antibody titer of local isolates irradiated by UV light 10x was 88.76 ± 33.06 IU/mL at week 4 with the lowest antibody titer values about 11.15 ± 9.18 IU/mL was found in the negative control.

Effect of whey goat milk kefir on hydrophobicity of E. coli O157:H7, S. typhi bacteria and C. albicans

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Dedi Fardiaz

2012-03-01

Full Text Available The hydrophobicity of bacteria. was determined using BATH (Bacteria adhesion to hydrocarbon test. All bacteria showed that 0,9 ml n-octane exposure gave a positive response and indicating that E. coli O157:H7 was categorized as moderate hydrophobic bacteria,  while S.  typhi  and C. albicans were catagorized as  highly hydrophobic bacteria. Goat Milk Kefir increased hydrophobicity of E.  coli O157:H7 by 24.40, however, decreased hydrophobicity of S. typhi by 47.56  and C. albicans by 70.14 percent, respectively. This finding showed that one of the inhibition mechanism may be caused by  an interaction  of  organic acid and peptide  compounds with cell membrane, in which hydrophobic sites of component  modified the hydrophobicity of the bacteria cell surface. The hydrophobicity modification in bacterial  cell wall might result inhibition of adhetion bacteria at cell host. Key words : Enterophatogenic bacteria, hidrophobisitas bacteria

Normalización y validación de ensayos inmunoenzimáticos para cuantificar IgG humana antileptospira serovares canicola canicola, icterohaemorrhagiae copenhageni y pomona mozdok.

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Xenia Ferriol

2001-06-01

Full Text Available Con el objetivo de evaluar la respuesta inmune inducida por la vacuna cubana vax-SPIRAL se desarrollaron tres ELISAs de tipo indirecto para la cuantificación de IgG humana antileptospira, en el cual se emplearon como antígenos de captura las células enteras de Leptospira interrogans de los serovares canicola canicola, icterohaemorrhagiae copenhageni y pomona mozdok, inactivadas con formaldehído y posteriormente desecadas a 33 °C durante 16-20 h en placas para ELISA. Para la cuantificación se empleó un suero estándar al que se le asignaron unidades arbitrarias, correspondientes al recíproco del título obtenido por microaglutinación (MAT. Estos fueron 31, 12 y 58 U/mL respectivamente para los tres serovares señalados que se incluyen en el preparado vacunal. Se utilizó un conjugado anti IgG humana-peroxidasa, el cual se une a los anticuerpos específicos contra cada serovar, la reacción se evidencia por la acción de la enzima sobre la mezcla sustratocromógeno (ortofenilendiamina que genera color. El método normalizado se validó para los tres serovares; la precisión intra e interensayos fueron excelentes, con coeficientes de variación inferiores al 10%. Las desviaciones de la recuperación y linealidad fueron también inferiores al 10%. El suero control se ubicaron para los tres serovares en la zona de mayor interés para las muestras. Los ELISAs mostraron un 100% de sensibilidad para los tres serovares y se obtuvieron valores de 93,33% de especificidad para los serovares canicola canicola e icterohaemorrhagiae copenagheni y de 100% para el serovar pomona mozdok. El límite de detección para cada uno de los serovares fue de 0,478; 0,127 y 0,632 U/mL respectivamente.

DETERMINASI SEROVAR BAKTERI LEPTOSPIRA PADA RESERVOIR DI KABUPATEN BANYUMAS

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Tri Ramadhani

2016-05-01

Full Text Available Leptospirosis is an infectious disease caused by pathogenic Leptospira. Leptospirosis transmitted to human through direct contact with body fluids of infected animals or indirectly through contaminated puddles . The prevalence of leptospirosis in Banyumas tends to increase for 3 years. The purpose of this study was to determine the leptospira serovar in reservoir to prove of a current infection. Surveys was conducted using single live traps for three consecutive days, determination of leptospira serovar was conducted using Microscopic Aglutination Test (MAT. Data analysis was performed by univariate and presented in tables and graphs. The results showed that the trapped animals consisted of Rattus tanezumi (70.6% and Suncus murinus (29.4% with 6.5% succsess trap. Rattus tanezumi were dominantly caught inside the house (51% than outside the house (49%. Female rats were dominantly caught (66.7% than male rats (33.3%. Suncus murinus and Rattus tanezumi shown a titer of 1/100 to be infected with L.icterohaemorrhagiae , L.javanica and L.cynopteri which are pathogenic Leptospira in humans. Efforts are needed to improve community participation in preventing tranmission of leptospirosis by avoiding contact with contaminated water and soil. For people who are risk of exposure to infected animal should wear protective clothes or footwear.

What Have We Learned From the Typhoid Fever Surveillance in Africa Program?

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Baker, Stephen; Hombach, Joachim; Marks, Florian

2016-03-15

The Typhoid Fever Surveillance in Africa Program (TSAP) was established in 2009 to fill the data void concerning invasive Salmonella disease in sub-Saharan Africa, and to specifically estimate the burden of bloodstream infections caused by the key pathogen, Salmonella enterica serovar Typhi. TSAP has achieved this ambitious target, finding high incidences of typhoid fever in both rural and urban populations in several countries in sub-Saharan Africa. The results of TSAP will undoubtedly dictate the direction of future typhoid fever research in Africa, and at last provides a key piece of the disease burden jigsaw puzzle. With the dawn of new Vi conjugate vaccines against Salmonella Typhi, the next priority for the typhoid community must be providing the required data on these vaccines so they can be licensed and provided to those in high-risk groups and locations across sub-Saharan Africa. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.

Expression and characterization of an iron-regulated hemin-binding protein, HbpA, from Leptospira interrogans serovar Lai.

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Asuthkar, Swapna; Velineni, Sridhar; Stadlmann, Johannes; Altmann, Friedrich; Sritharan, Manjula

2007-09-01

In an earlier study, based on the ferric enterobactin receptor FepA of Escherichia coli, we identified and modeled a TonB-dependent outer membrane receptor protein (LB191) from the genome of Leptospira interrogans serovar Lai. Based on in silico analysis, we hypothesized that this protein was an iron-dependent hemin-binding protein. In this study, we provide experimental evidence to prove that this protein, termed HbpA (hemin-binding protein A), is indeed an iron-regulated hemin-binding protein. We cloned and expressed the full-length 81-kDa recombinant rHbpA protein and a truncated 55-kDa protein from L. interrogans serovar Lai, both of which bind hemin-agarose. Assay of hemin-associated peroxidase activity and spectrofluorimetric analysis provided confirmatory evidence of hemin binding by HbpA. Immunofluorescence studies by confocal microscopy and the microscopic agglutination test demonstrated the surface localization and the iron-regulated expression of HbpA in L. interrogans. Southern blot analysis confirmed our earlier observation that the hbpA gene was present only in some of the pathogenic serovars and was absent in Leptospira biflexa. Hemin-agarose affinity studies showed another hemin-binding protein with a molecular mass of approximately 44 kDa, whose expression was independent of iron levels. This protein was seen in several serovars, including nonpathogenic L. biflexa. Sequence analysis and immunoreactivity with specific antibodies showed this protein to be LipL41.

Nalidixic acid-resistant Salmonella enteric serotype typhi infection presenting with sub-intestinal obstruction and mesenteric adenitis

International Nuclear Information System (INIS)

Al-Khuwaitir, Tarig S.; Al-Zuhair, Amin A.; Al-Ghamdi, Ali G.; Khan, A.

2008-01-01

Nalidixic acid-resistant Salmonella typhi NARST infections increase minimal inhibitory concentrations of fluoroquinolones, due to chromosomal mutations in the gene encoding DNA gyrase, and can lead to a delayed treatment response. This in turn alters the course of the disease allowing for a protracted period of illness and the occurrence of complications. In this case report, we present a patient from the Indian sub-continent, who was diagnosed with NARST complicated by sub-intestinal obstruction, her diagnosis, treatment and subsequent recovery. (author)

Experimental infection of laying hens with Salmonella enterica serovar Gallinarum Infecção experimental com Salmonella enterica serovar Gallinarum em poedeiras comerciais

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Gláucia Helaine de Oliveira

2005-03-01

Full Text Available Experimental infections were set up in commercial laying birds, comprising a white relatively resistant line and a red susceptible line infecting with Salmonella enterica serovar Gallinarum. The major findings were that in susceptible birds clinical disease occurred in a dose-dependent manner. Faecal excretion occurred in susceptible birds almost up to death but also occurred in the more resistant line and in birds, which were convalescing. Removal of birds, which had died from the disease, from the environment, reduced the resultant mortality/morbidity and may be regarded as a useful measure for control.Infecções experimentais por Salmonella enterica serovar Gallinarum foram realizadas em aves de postura comercial, incluindo uma linhagem branca resistente e uma linhagem vermelha susceptível ao desenvolvimento da enfermidade clínica. As aves de linhagem susceptível apresentaram doença clínica dependente da dose administrada. Excreção fecal foi observada em aves da linhagem susceptível próximo ao momento da morte e, eventualmente, em aves da linhagem resistente e aves convalescentes. A remoção das aves mortas do meio ambiente reduziu a taxa de mortalidade/morbidade, procedimento este que pode ser utilizado como medida de controle.

Global Genomic Epidemiology of Salmonella enterica Serovar Typhimurium DT104

DEFF Research Database (Denmark)

Leekitcharoenphon, Pimlapas; Hendriksen, Rene S.; Le Hello, Simon

2016-01-01

It has been 30 years since the initial emergence and subsequent rapid global spread of multidrug-resistant Salmonella enterica serovar Typhimurium DT104 (MDR DT104). Nonetheless, its origin and transmission route have never been revealed. We used whole-genome sequencing (WGS) and temporally struc...

A Review of Prognostic Models on Diagnosis and Therapeutic Strategies of Typhoid Fever

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Aslam Babar

2018-05-01

Full Text Available Background:      Typhoid infection is an insidious onset type of fever and some other gastrointestinal disorders which may have a fatal outcome. The causative agents are Salmonella typhi, Salmonella paratyphi A, and Salmonella paratyphi B.  Clinical features include, gradual rising fever, white coated tongue, and severe degree of malaise, drowsiness and pain in abdomen, perforation with bleeding in the intestines, shock and death. It involves mostly male victims of school going age. It is water born disease which spreads due to poor sanitation mostly in congested populated areas. According to World Health Organization sixteen to seventeen million typhoid fever cases were reported annually, out of which 600,000 died. Typhoid fever is 10 to 29 times more in subcontinent than China. Infection only occurs when food is handled by infected person. Isolated strains of Salmonella spp from suspected cases show resistance against routine antibiotics and the modern antibiotics are much more expensive and un affordable.Conclusion:    Need of this review is especially for Silver Nanoparticles (AgNPs manufactured by some types of fungi introduced by recent researchers have an edge to control or treat some sort of infections due to their antibacterial properties. In this study these (AgNPs in the form of suspension, give positive results against the Salmonella species. It enables us to treat the typhoid infection in a less expensive way.

Storing drinking-water in copper pots kills contaminating diarrhoeagenic bacteria.

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Sudha, V B Preethi; Ganesan, Sheeba; Pazhani, G P; Ramamurthy, T; Nair, G B; Venkatasubramanian, Padma

2012-03-01

Microbially-unsafe water is still a major concern in most developing countries. Although many water-purification methods exist, these are expensive and beyond the reach of many people, especially in rural areas. Ayurveda recommends the use of copper for storing drinking-water. Therefore, the objective of this study was to evaluate the effect of copper pot on microbially-contaminated drinking-water. The antibacterial effect of copper pot against important diarrhoeagenic bacteria, including Vibrio cholerae O1, Shigella flexneri 2a, enterotoxigenic Escherichia coli, enteropathogenic E. coli, Salmonella enterica Typhi, and Salmonella Paratyphi is reported. When drinking-water (pH 7.83 +/- 0.4; source: ground) was contaminated with 500 CFU/mL of the above bacteria and stored in copper pots for 16 hours at room temperature, no bacteria could be recovered on the culture medium. Recovery failed even after resuscitation in enrichment broth, followed by plating on selective media, indicating loss of culturability. This is the first report on the effect of copper on S. flexneri 2a, enteropathogenic E. coli, and Salmonella Paratyphi. After 16 hours, there was a slight increase in the pH of water from 7.83 to 7.93 in the copper pots while the other physicochemical parameters remained unchanged. Copper content (177 +/- 16 ppb) in water stored in copper pots was well within the permissible limits of the World Health Organization. Copper holds promise as a point-of-use solution for microbial purification of drinking-water, especially in developing countries.

Temperature and oxygen dependent metabolite utilization by Salmonella enterica serovars Derby and Mbandaka.

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Matthew R Hayward

Full Text Available Salmonella enterica is a zoonotic pathogen of clinical and veterinary significance, with over 2500 serovars. In previous work we compared two serovars displaying host associations inferred from isolation statistics. Here, to validate genome sequence data and to expand on the role of environmental metabolite constitution in host range determination we use a phenotypic microarray approach to assess the ability of these serovars to metabolise ~500 substrates at 25°C with oxygen (aerobic conditions to represent the ex vivo environment and at 37°C with and without oxygen (aerobic/anaerobic conditions to represent the in vivo environment. A total of 26 substrates elicited a significant difference in the rate of metabolism of which only one, D-galactonic acid-g-lactone, could be explained by the presence (S. Mbandaka or the absence (S. Derby of metabolic genes. We find that S. Mbandaka respires more efficiently at ambient temperatures and under aerobic conditions on 18 substrates including: glucosominic acid, saccharic acid, trehalose, fumaric acid, maltotriose, N-acetyl-D-glucosamine, N-acetyl-beta-D-mannosamine, fucose, L-serine and dihydroxy-acetone; whereas S. Derby is more metabolically competent anaerobically at 37°C for dipeptides, glutamine-glutamine, alanine-lysine, asparagine-glutamine and nitrogen sources glycine and nitrite. We conclude that the specific phenotype cannot be reliably predicted from the presence of metabolic genes directly relating to the metabolic pathways under study.

Evaluation of different analysis and identification methods for Salmonella detection in surface drinking water sources

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Hsu, Bing-Mu, E-mail: bmhsu@ccu.edu.tw [Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC (China); Huang, Kuan-Hao; Huang, Shih-Wei [Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC (China); Tseng, Kuo-Chih [Department of Internal Medicine, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan, ROC (China); Su, Ming-Jen [Department of Clinical Pathology, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan, ROC (China); Lin, Wei-Chen; Ji, Dar-Der [Research and Diagnostic Center, Centers for Disease Control, Taipei, Taiwan, ROC (China); Shih, Feng-Cheng; Chen, Jyh-Larng [Department of Environmental Engineering and Health, Yuanpei University of Science and Technology, HsinChu, Taiwan, ROC (China); Kao, Po-Min [Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC (China)

2011-09-15

The standard method for detecting Salmonella generally analyzes food or fecal samples. Salmonella often occur in relatively low concentrations in environmental waters. Therefore, some form of concentration and proliferation may be needed. This study compares three Salmonella analysis methods and develops a new Salmonella detection procedure for use in environmental water samples. The new procedure for Salmonella detection include water concentration, nutrient broth enrichment, selection of Salmonella containing broth by PCR, isolation of Salmonella strains by selective culture plates, detection of possible Salmonella isolate by PCR, and biochemical testing. Serological assay and pulsed-field gel electrophoresis (PFGE) can be used to identify Salmonella serotype and genotype, respectively. This study analyzed 116 raw water samples taken from 18 water plants and belonging to 5 watersheds. Of these 116, 10 water samples (8.6%) taken from 7 water plants and belonging to 4 watersheds were positive for a Salmonella-specific polymerase chain reaction targeting the invA gene. Guided by serological assay results, this study identified 7 cultured Salmonella isolates as Salmonella enterica serovar: Alnaby, Enteritidis, Houten, Montevideo, Newport, Paratyphi B var. Java, and Victoria. These seven Salmonella serovars were identified in clinical cases for the same geographical areas, but only one of them was 100% homologous with clinical cases in the PFGE pattern. - Research highlights: {yields} A new Salmonella detecting procedure for environmental water is developed. {yields} Salmonella isolates are identified by serological assay and PFGE. {yields} A total of seven Salmonella serovars is isolated from environmental water.

Evaluation of different analysis and identification methods for Salmonella detection in surface drinking water sources

International Nuclear Information System (INIS)

Hsu, Bing-Mu; Huang, Kuan-Hao; Huang, Shih-Wei; Tseng, Kuo-Chih; Su, Ming-Jen; Lin, Wei-Chen; Ji, Dar-Der; Shih, Feng-Cheng; Chen, Jyh-Larng; Kao, Po-Min

2011-01-01

The standard method for detecting Salmonella generally analyzes food or fecal samples. Salmonella often occur in relatively low concentrations in environmental waters. Therefore, some form of concentration and proliferation may be needed. This study compares three Salmonella analysis methods and develops a new Salmonella detection procedure for use in environmental water samples. The new procedure for Salmonella detection include water concentration, nutrient broth enrichment, selection of Salmonella containing broth by PCR, isolation of Salmonella strains by selective culture plates, detection of possible Salmonella isolate by PCR, and biochemical testing. Serological assay and pulsed-field gel electrophoresis (PFGE) can be used to identify Salmonella serotype and genotype, respectively. This study analyzed 116 raw water samples taken from 18 water plants and belonging to 5 watersheds. Of these 116, 10 water samples (8.6%) taken from 7 water plants and belonging to 4 watersheds were positive for a Salmonella-specific polymerase chain reaction targeting the invA gene. Guided by serological assay results, this study identified 7 cultured Salmonella isolates as Salmonella enterica serovar: Alnaby, Enteritidis, Houten, Montevideo, Newport, Paratyphi B var. Java, and Victoria. These seven Salmonella serovars were identified in clinical cases for the same geographical areas, but only one of them was 100% homologous with clinical cases in the PFGE pattern. - Research highlights: → A new Salmonella detecting procedure for environmental water is developed. → Salmonella isolates are identified by serological assay and PFGE. → A total of seven Salmonella serovars is isolated from environmental water.

Species and serovars of the genus Listeria lsolated from different sources in Brazil from 1971 to 1997

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Hofer Ernesto

2000-01-01

Full Text Available Using phenotype techniques, characterization was made to species and serovar of 3,112 strains of Listeria, isolated from different sources of infection such as human (247-7.9% and animals (239-7.6%, as well as from various routes of infection, including food (2,330-74.8% and environmental constituents (296-9.5%, all coming from different regions of the country and collected during the period 1971-1997. The following species were recovered in the cultures analysed: L. monocytogenes (774-24.8%, L. innocua (2,269-72.9%, L. seeligeri (37-1.1%, L. welshimeri (22-0.7%, L. grayi (9-0.2%, and L. ivanovii (1-0.03%. L. monocytogenes was represented by ten serovars, the most prevalent being 4b (352-11.3%, 1/2a (162-5.2%, and 1/2b (148-4.7%. The predominant serovar in L. innocua was 6a (2,093-67.2%. Considerations about laboratory methods for diagnosis and epidemiological aspects are presented on the basis of the results obtained.

Identification of Salmonella serovars isolated from live molluscan shellfish and their significance in the marine environment.

Science.gov (United States)

Martinez-Urtaza, Jaime; Saco, Montserrat; Hernandez-Cordova, Gustavo; Lozano, Antonio; Garcia-Martin, Oscar; Espinosa, Joaquin

2003-02-01

A study on the presence of Salmonella spp. in live molluscs was performed, which included a description of the different serovars isolated and their relationship to the marine environment. A total of 2,980 samples of shellfish from Galicia (N.W. Spain) were tested for the presence of Salmonella spp. between September 1998 and August 2001. The overall incidence of Salmonella was 1.8% and showed a slight rise during the 3 years of the study. Mussels and oysters presented a higher incidence than clams and cockles, possibly because of their distinct growing habitat. A seasonal pattern was noted for the isolation of Salmonella spp.: 54% of the isolations were detected from September to November. That nearly 67% of the total Salmonella was isolated from shellfish with fecal coliform levels fecal coliforms do not necessarily indicate the absence of Salmonella. A total of nine serovars were found in the 54 Salmonella isolated. Salmonella Senftenberg was the most frequent (50%), followed by Salmonella Typhimurium (18%) and Salmonella Agona (17%). Salmonella Senftenberg was detected frequently during the year, whereas the remaining serovars were detected only on occasional contamination events.

SEROPREVALENCE OF NINE LEPTOSPIRA INTERROGANS SEROVARS IN WILD CARNIVORES, UNGULATES, AND PRIMATES FROM A ZOO POPULATION IN A METROPOLITAN REGION OF CHILE.

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Moreno-Beas, Eduardo; Abalos, Pedro; Hidalgo-Hermoso, Ezequiel

2015-12-01

Serum samples from 130 individuals representing 42 species of carnivores, ungulates, and primates from a population of captive mammals in Metropolitan Region in Chile were tested for antibodies against nine serovars of Leptospira interrogans using the microscopic agglutination test. Ten percent of the animals were seropositive to one or more serovars. Seroprevalence was significantly higher in ungulates (20.4%) compared to carnivores (3.8%) and primates (3.4%). There were no significant differences in seroprevalence among sex and age ranges. The most frequent serovar detected was Autumnalis, present in 53.4% of antibody-positive animals. Most positive animals had titers of ≤1 : 200, except for a maned wolf ( Chrysocyon brachyurus ) with titers of 1 : 400 against serovar Hardjo. To the authors' knowledge, this is the first report of Leptospira exposure detected in native endangered pudu ( Pudu puda ) and the first confirmation of exposure to L. interrogans in captive wild mammals in Chile. Leptospirosis should be considered as a differential diagnosis in future disease presentation for hepatitis or abortions in captive mammals in Chile.

Dam methylation participates in the regulation of PmrA/PmrB and RcsC/RcsD/RcsB two component regulatory systems in Salmonella enterica serovar Enteritidis.

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Sebastián Hernán Sarnacki

Full Text Available The absence of Dam in Salmonella enterica serovar Enteritidis causes a defect in lipopolysaccharide (LPS pattern associated to a reduced expression of wzz gene. Wzz is the chain length regulator of the LPS O-antigen. Here we investigated whether Dam regulates wzz gene expression through its two known regulators, PmrA and RcsB. Thus, the expression of rcsB and pmrA was monitored by quantitative real-time RT-PCR and Western blotting using fusions with 3×FLAG tag in wild type (wt and dam strains of S. Enteritidis. Dam regulated the expression of both rcsB and pmrA genes; nevertheless, the defect in LPS pattern was only related to a diminished expression of RcsB. Interestingly, regulation of wzz in serovar Enteritidis differed from that reported earlier for serovar Typhimurium; RcsB induces wzz expression in both serovars, whereas PmrA induces wzz in S. Typhimurium but represses it in serovar Enteritidis. Moreover, we found that in S. Enteritidis there is an interaction between both wzz regulators: RcsB stimulates the expression of pmrA and PmrA represses the expression of rcsB. Our results would be an example of differential regulation of orthologous genes expression, providing differences in phenotypic traits between closely related bacterial serovars.

[Enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to Salmonella Typhi lipopolysaccharide O and capsular polysaccharide Vi antigens in persons from outbreak of typhoid fever].

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Rastawicki, Waldemar; Kałużewski, Stanisław

2015-01-01

The laboratory diagnosis of typhoid fever is dependent upon either isolation of S. Typhi from a clinical sample or the detection of raised titers of serum antibodies in the Widal test or the passive hemagglutination assay (PHA). In this study we evaluated the usefulness of ELISA for detection of antibodies to S. Typhi lipopolysaccharide O and capsular polysaccharide Vi antigens in the sera of persons from outbreak of typhoid fever. Fifteen serum samples from patients with laboratory confirmed typhoid fever and 140 sera from persons suspected for contact with typhoid fever patients from outbreak in 1974/75 in Poland were tested by ELISA. Additionally, as the control group, we tested 115 sera from blood donors for the presence of S. Typhi anti-LPS and anti-Vi antibodies. Anti-LPS and anti-Vi antibodies were detected in 80% and 53.3% of sera obtained from patients with laboratory confirmed typhoid fever, respectively. The high percentages of positive results in ELISA were also noted in the group of persons suspected for contact with typhoid fever patients (51.4% and 45%) but not in the group of blood donors (7.8% and 6.1%, respectively). The ELISA could be a useful tool for the serological diagnosis of typhoid fever in patients who have clinical symptoms but are culture negative, especially during massive outbreaks of typhoid fever.

Detoxication of endotoxins from the enteric group of bacteria using gamma-irradiation

Energy Technology Data Exchange (ETDEWEB)

Tumanian, M A; Dunlishcheva, A P; Sinilova, N G; Ivanov, K K

1975-03-01

A study was made of the effect of gamma radiation on the toxic properties of endotoxins of the O-somatic antigens and lipopolysaccharides separated from various representatives of the enterobacteriaceae: S. typhi 2 4446, S. paratyphi B42, B. proteus vulgaris 1 and mirabilis 4, E. coli K12 and 5396/38 and Sh. dysenteriae flexneri 516 and 550. An irradiation dose of 1 mrad led to an insignificant decrease in toxicity, while a dose of 3 mrad led to a decrease in toxicity by a factor of 3 to 4 in comparison with the toxicity of the initial preparation. The decrease in toxicity under the effect of irradiation is apparently connected with the lipid part of the endotoxin molecule. The irradiation results in a decrease in the molecular weight of the endotoxin. The infrared spectrum of the molecule shows considerable changes at high radiation doses. (SJR)

5-Nitroimidazole Derivatives and their Antimicrobial Activity

International Nuclear Information System (INIS)

Khan, K.M.; Salar, U.; Yousuf, S.; Naz, F.

2016-01-01

5-Nitroimidazole derivatives 2-8 were synthesized from secnidazole. The syntheses were accomplished in two steps which start from the oxidation of secnidazole to the secnidazolone 1. Secnidazolone 1 was converted into its hydrazone derivative 2-8 by treating with different substituted acid hydrazide. Compounds 2-8 were evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria, compounds 3 and 4 showed the significant activity against Staphylococcus epidermidis, however, compound 2 showed good inhibitions against Corynebacterium diphtheria when compared with the standard. Compound 3 showed good inhibitory potential against tested Gram-negative bacterial strains i.e. Enterobacter aerogene, Escherichia coli, Salmonella typhi, Salmonella paratyphi A, Shigella flexeneri and Vibrio choleriae. All synthetic derivatives were also tested against eight fungal stains, however, they were weekly active against Aspergillus flavus and Candida albican. The synthesized compounds were characterized by different spectroscopy techniques. (author)

A large outbreak of typhoid fever associated with a high rate of intestinal perforation in Kasese District, Uganda, 2008-2009.

Science.gov (United States)

Neil, Karen P; Sodha, Samir V; Lukwago, Luswa; O-Tipo, Shikanga; Mikoleit, Matthew; Simington, Sherricka D; Mukobi, Peter; Balinandi, Stephen; Majalija, Samuel; Ayers, Joseph; Kagirita, Atek; Wefula, Edward; Asiimwe, Frank; Kweyamba, Vianney; Talkington, Deborah; Shieh, Wun-Ju; Adem, Patricia; Batten, Brigid C; Zaki, Sherif R; Mintz, Eric

2012-04-01

Salmonella enterica serovar Typhi (Salmonella Typhi) causes an estimated 22 million typhoid fever cases and 216 000 deaths annually worldwide. In Africa, the lack of laboratory diagnostic capacity limits the ability to recognize endemic typhoid fever and to detect outbreaks. We report a large laboratory-confirmed outbreak of typhoid fever in Uganda with a high proportion of intestinal perforations (IPs). A suspected case of typhoid fever was defined as fever and abdominal pain in a person with either vomiting, diarrhea, constipation, headache, weakness, arthralgia, poor response to antimalarial medications, or IP. From March 4, 2009 to April 17, 2009, specimens for blood and stool cultures and serology were collected from suspected cases. Antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE) were performed on Salmonella Typhi isolates. Surgical specimens from patients with IP were examined. A community survey was conducted to characterize the extent of the outbreak. From December 27, 2007 to July 30, 2009, 577 cases, 289 hospitalizations, 249 IPs, and 47 deaths from typhoid fever occurred; Salmonella Typhi was isolated from 27 (33%) of 81 patients. Isolates demonstrated multiple PFGE patterns and uniform susceptibility to ciprofloxacin. Surgical specimens from 30 patients were consistent with typhoid fever. Estimated typhoid fever incidence in the community survey was 8092 cases per 100 000 persons. This typhoid fever outbreak was detected because of an elevated number of IPs. Underreporting of milder illnesses and delayed and inadequate antimicrobial treatment contributed to the high perforation rate. Enhancing laboratory capacity for detection is critical to improving typhoid fever control.

Molecular identification of common Salmonella serovars using multiplex DNA sensor-based suspension array.

Science.gov (United States)

Aydin, Muhsin; Carter-Conger, Jacqueline; Gao, Ning; Gilmore, David F; Ricke, Steven C; Ahn, Soohyoun

2018-04-01

Salmonella is one of major foodborne pathogens and the leading cause of foodborne illness-related hospitalizations and deaths. It is critical to develop a sensitive and rapid detection assay that can identify Salmonella to ensure food safety. In this study, a DNA sensor-based suspension array system of high multiplexing ability was developed to identify eight Salmonella serovars commonly associated with foodborne outbreaks to the serotype level. Each DNA sensor was prepared by activating pre-encoded microspheres with oligonucleotide probes that are targeting virulence genes and serovar-specific regions. The mixture of 12 different types of DNA sensors were loaded into a 96-well microplate and used as a 12-plex DNA sensor array platform. DNA isolated from Salmonella was amplified by multiplex polymerase chain reaction (mPCR), and the presence of Salmonella was determined by reading fluorescent signals from hybridization between probes on DNA sensors and fluorescently labeled target DNA using the Bio-Plex® system. The developed multiplex array was able to detect synthetic DNA at the concentration as low as 100 fM and various Salmonella serovars as low as 100 CFU/mL within 1 h post-PCR. Sensitivity of this assay was further improved to 1 CFU/mL with 6-h enrichment. The array system also correctly and specifically identified serotype of tested Salmonella strains without any cross-reactivity with other common foodborne pathogens. Our results indicate the developed DNA sensor suspension array can be a rapid and reliable high-throughput method for simultaneous detection and molecular identification of common Salmonella serotypes.

Diversity and antimicrobial susceptibility of Salmonella enterica serovars isolated from pig farms in Ibadan, Nigeria

DEFF Research Database (Denmark)

Fashae, Kayode; Hendriksen, Rene S.

2014-01-01

of plasmid-mediated quinolone resistance (PMQR) genes in pigs in Ibadan, Nigeria. Pooled fresh pen floor fecal samples of pigs collected from 31 pig farms were cultured; the Salmonella isolates were serotyped and their antimicrobial susceptibility was determined. PMQR genes were screened by polymerase chain...... Kingston (n = 13; 5.7 %). The most widely distributed serovars among the farms were Salmonella Give (six farms) and Salmonella Elisaberthville (six farms). Resistance to chloramphenicol, sulfonamides, nalidixic acid, streptomycin, and tetracycline ranged from 11.6 % (n = 26) to 22.8 % (n = 51). Resistance....... Other PMQR genes were not detected. Pigs constitute an important source of diverse Salmonella serovars in Ibadan. The isolates were more resistant to old antimicrobials with some multiple resistant. Control measures and regulation of antimicrobials are warranted....

ANTIBACTERIAL ACTIVITY OF SILVER NANOPARTICLES: SENSITIVITY OF DIFFERENT SALMONELLA SEROVARS

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Carmen eLosasso

2014-05-01

Full Text Available Salmonella spp. is one of the main causes of foodborne illnesses in humans worldwide. Consequently, great interest exists in reducing its impact on human health by lowering its prevalence in the food chain. Antimicrobial formulations in the form of nanoparticles exert bactericidal action due to their enhanced reactivity resultant from their high surface/volume ratio. Silver nanoparticles (AgNPs are known to be highly toxic to Gram-negative and Gram-positive microorganisms, including multidrug resistant bacteria. However, few data concerning their success against different Salmonella serovars are available. Aims of the present study were to test the antimicrobial effectiveness of AgNPs, against Salmonella Enteritidis, Hadar and Senftenberg, and to investigate the causes of their different survival abilities from a molecular point of view.Results showed an immediate, time-limited and serovar-dependent reduction of bacterial viability. In the case of S. Senftenberg, the reduction in numbers was observed for up to 4 h of incubation in the presence of 200 mg/L of AgNPs; on the contrary, S. Enteritidis and S. Hadar resulted to be inhibited for up to 48 h. RT-PCR experiments demonstrated the constitutive expression of the plasmidic silver resistance determinant (SilB by S. Senftenberg, thus suggesting the importance of a cautious use of AgNPs.

Multiple‐locus variable‐number tandem repeat analysis of Salmonella enterica subsp. enterica serovar Dublin

DEFF Research Database (Denmark)

Kjeldsen, M. K.; Torpdahl, M.; Campos, J.

2014-01-01

Salmonella serovar Dublin causes disease in cattle and leads to considerable production losses. In humans, severe invasive disease and high mortality rates are reported. The presently available typing methods provide insufficient discrimination within Salm. Dublin for epidemiological investigatio...

Influence of Temperature and Predation on Survival of Salmonella enterica Serovar Typhimurium and Expression of invA in Soil and Manure-Amended Soil▿

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García, R.; Bælum, J.; Fredslund, L.; Santorum, P.; Jacobsen, C. S.

2010-01-01

The effects of three temperatures (5, 15, and 25°C) on the survival of Salmonella enterica serovar Typhimurium in topsoil were investigated in small microcosms by three different techniques: plate counting, invA gene quantification, and invA mRNA quantification. Differences in survival were related to the effect of protozoan predation. Tetracycline-resistant Salmonella serovar Typhimurium was inoculated into soil and manure-amended soil at 1.5 × 108 cells g soil−1. Population densities were determined by plate counting and by molecular methods and monitored for 42 days. Simultaneous extraction of RNA and DNA, followed by quantitative PCR, was used to investigate invA gene levels and expression. Analysis by these three techniques showed that Salmonella serovar Typhimurium survived better at 5°C. Comparing DNA and CFU levels, significantly higher values were determined by DNA-based techniques. invA mRNA levels showed a fast decrease in activity, with no detectable mRNA after an incubation period of less than 4 days in any of the soil scenarios. A negative correlation was found between Salmonella serovar Typhimurium CFU levels and protozoan most probable numbers, and we propose the role of the predator-prey interaction as a factor to explain the die-off of the introduced strain by both culture- and DNA quantification-based methods. The results indicate that temperature, manure, and protozoan predation are important factors influencing the survival of Salmonella serovar Typhimurium in soil. PMID:20562283

Alternate phase variation in expression of two major surface membrane proteins (MBA and UU376) of Ureaplasma parvum serovar 3.

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Zimmerman, Carl-Ulrich R; Stiedl, Thomas; Rosengarten, Renate; Spergser, Joachim

2009-03-01

Ureaplasma urealyticum and Ureaplasma parvum are commensals and pathogens of the human urogenital tract and of newborn infants. There are four distinct U. parvum serovars and 10 distinct U. urealyticum serovars. Both species possess a distinct immunodominant variable surface protein, the multiple banded antigen (MBA), which shows size variability among isolates as a result of changes in the number of C-terminal repeating units. Adjacent to the MBA gene (UU375) lies UU376, which was annotated as 'Ureaplasma-specific conserved hypothetical gene'. In four different strains of U. parvum serovar 3, we demonstrated expression of UU376 by Western blot analysis and phase variation between UU376, here designated Upvmp376 (Ureaplasma phase-variable membrane protein 376), and MBA after application of selective pressure with hyperimmune antisera directed against either protein. By Southern blot analysis, we found that the switch between MBA and Upvmp376 expression is associated with a DNA inversion event in which the nonrepetitive region of the MBA gene and its putative promoter region are opposed to either the repetitive region of MBA or UU376. We propose that in U. parvum serovar 3, and presumably in all U. parvum and U. urealyticum, an inversion event at specific sites effects an alternate ON/OFF switching of the genes UU375 and UU376.

Utilization of a ts-sacB selection system for the generation of a Mycobacterium avium serovar-8 specific glycopeptidolipid allelic exchange mutant

Science.gov (United States)

Irani, Vida R; Lee, Sun-Hwa; Eckstein, Torsten M; Inamine, Julia M; Belisle, John T; Maslow, Joel N

2004-01-01

Background Mycobacterium avium are ubiquitous environmental organisms and a cause of disseminated infection in patients with end-stage AIDS. The glycopeptidolipids (GPL) of M. avium are proposed to participate in the pathogenesis of this organism, however, establishment of a clear role for GPL in disease production has been limited by the inability to genetically manipulate M. avium. Methods To be able to study the role of the GPL in M. avium pathogenesis, a ts-sacB selection system, not previously used in M. avium, was employed as a means to achieve homologous recombination for the rhamnosyltransferase (rtfA) gene of a pathogenic serovar 8 strain of M. avium to prevent addition of serovar-specific sugars to rhamnose of the fatty acyl-peptide backbone of GPL. The genotype of the resultant rtfA mutant was confirmed by polymerase chain reaction and southern hybridization. Disruption in the proximal sugar of the haptenic oligosaccharide resulted in the loss of serovar specific GPL with no change in the pattern of non-serovar specific GPL moieties as shown by thin layer chromatography and gas chromatography/mass spectrometry. Complementation of wild type (wt) rtfA in trans through an integrative plasmid restored serovar-8 specific GPL expression identical to wt serovar 8 parent strain. Results In this study, we affirm our results that rtfA encodes an enzyme responsible for the transfer of Rha to 6d-Tal and provide evidence of a second allelic exchange mutagenesis system suitable for M. avium. Conclusion We report the second allelic exchange system for M. avium utilizing ts-sacB as double-negative and xylE as positive counter-selection markers, respectively. This system of allelic exchange would be especially useful for M. avium strains that demonstrate significant isoniazid (INH) resistance despite transformation with katG. Through the construction of mutants in GPL or other mycobacterial components, their roles in M. avium pathogenesis, biosynthesis, or drug

Utilization of a ts-sacB selection system for the generation of a Mycobacterium avium serovar-8 specific glycopeptidolipid allelic exchange mutant

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Belisle John T

2004-09-01

Full Text Available Abstract Background Mycobacterium avium are ubiquitous environmental organisms and a cause of disseminated infection in patients with end-stage AIDS. The glycopeptidolipids (GPL of M. avium are proposed to participate in the pathogenesis of this organism, however, establishment of a clear role for GPL in disease production has been limited by the inability to genetically manipulate M. avium. Methods To be able to study the role of the GPL in M. avium pathogenesis, a ts-sacB selection system, not previously used in M. avium, was employed as a means to achieve homologous recombination for the rhamnosyltransferase (rtfA gene of a pathogenic serovar 8 strain of M. avium to prevent addition of serovar-specific sugars to rhamnose of the fatty acyl-peptide backbone of GPL. The genotype of the resultant rtfA mutant was confirmed by polymerase chain reaction and southern hybridization. Disruption in the proximal sugar of the haptenic oligosaccharide resulted in the loss of serovar specific GPL with no change in the pattern of non-serovar specific GPL moieties as shown by thin layer chromatography and gas chromatography/mass spectrometry. Complementation of wild type (wt rtfA in trans through an integrative plasmid restored serovar-8 specific GPL expression identical to wt serovar 8 parent strain. Results In this study, we affirm our results that rtfA encodes an enzyme responsible for the transfer of Rha to 6d-Tal and provide evidence of a second allelic exchange mutagenesis system suitable for M. avium. Conclusion We report the second allelic exchange system for M. avium utilizing ts-sacB as double-negative and xylE as positive counter-selection markers, respectively. This system of allelic exchange would be especially useful for M. avium strains that demonstrate significant isoniazid (INH resistance despite transformation with katG. Through the construction of mutants in GPL or other mycobacterial components, their roles in M. avium pathogenesis

[Epidemiological characteristics of typhoid fever and antibiotic susceptibility testing of Salmonella Typhi isolates in Guangxi, 1994-2013].

Science.gov (United States)

Wang, Mingliu; Kan, Biao; Yang, Jin; Lin, Mei; Yan, Meiying; Zeng, Jun; Quan, Yi; Liao, Hezhuang; Zhou, Lingyun; Jiang, Zhenling; Huang, Dehui

2014-08-01

Through analyzing the typhoid epidemics and to determine and monitor regional resistance characteristics of the shift of drug resistant profile on Salmonella (S.) Typhi, to understand the related epidemiological characteristics of typhoid fever and to provide evidence for the development of strategies, in Guangxi. Data of typhoid fever from surveillance and reporting system between 1994 to 2013 was collected and statistically analyzed epidemiologically. The susceptibility of 475 S. Typhi isolates from patients on ten antibiotics was tested by broth micro-dilution method and minimum inhibition concentration was obtained and interpreted based on the CLSI standard. From 1994 to 2013, a total of 57 928 cases of typhoid fever were reported in Guangxi province with an annual incidence of 6.29/100 000 and mortality as 0.03%. The higher incidence was observed in the population under 20 years of age. There was no significant difference on incidence between male and female, but farmers and students were among the hardest hit groups. More cases were seen from the northern part of the province. Cases appeared all year round with the peak from May to October. A total of 13 major outbreaks during 2001 to 2013 were reported and the main transmission route was water-borne. All the strains were sensitive to third generation cephalosporins cefotaxime and fluoroquinolones norfloxacin. The susceptibility rates to tetracycline, chloramphenicol, ampicillin and gentamicin was around 98% but relative lower susceptible rate to ciprofloxacin was seen as 89.89% . The lowest susceptibility was found for streptomycin and sulfamethoxazole agents, with the rates as 67.73% and 65.89% , respectively. One strain was found to have been resistant to ciprofloxacin and another 47 isolates with reduced susceptibility to ciprofloxacin. Twenty eight isolates were found to be resistant to multiple antibiotics and one displayed ampicillin, chloramphenicol, streptomycin, sulfamethoxazole tetracycline and

Combination of PCR targeting the VD2 of omp1 and reverse line blot analysis for typing of urogenital Chlamydia trachomatis serovars in cervical scrape specimens.

NARCIS (Netherlands)

Molano, M; Meijer, C.J.L.M.; Morre, S.A.; Pol, R; Brule, van den AJ

2004-01-01

50% contained both serovars D and E. The nested VD2 PCR-RLB developed is a simple, fast, and specific method for the identification of individual urogenital C. trachomatis serovars previously detected by using plasmid PCR. Moreover, it is an appropriate method for studying multiple C. trachomatis

In Vitro Development of Ciprofloxacin Resistance of Salmonella enterica Serovars Typhimurium, Enteritidis, and Indiana Isolates from Food Animals.

Science.gov (United States)

Zhang, Wen-Hui; Zhang, Chuan-Zhen; Liu, Zhi-Jie; Gu, Xi-Xi; Li, Wan; Yang, Ling; Liu, Ya-Hong; Zeng, Zhen-Ling; Jiang, Hong-Xia

2017-09-01

Difference in the development of resistance may be associated with the epidemiological spread and drug resistance of different Salmonella enterica serovar strains. In the present study, three susceptible S. enterica serovars, Typhimurium (ST), Enteritidis (SE), and Indiana (SI) strains, were subjected to stepwise selection with increasing ciprofloxacin concentrations. The results indicated that the mutation frequencies of the SI group were 10 1 -10 4 higher and developed resistance to ciprofloxacin more rapidly compared with the ST and SE groups. Ciprofloxacin accumulation in the SI strain was also higher than the other two strains in the presence of an efflux pump inhibitor. The development of ciprofloxacin resistance was quite different among the three serovar strains. In SI, increasing AcrAB-TolC efflux pump expression and single or double mutations in gyrA with or without a single parC mutation (T57S) were found in the development of ciprofloxacin resistance. In SE, an increase in the AcrAB-TolC efflux pump regulatory gene ramA gradually decreased as resistant bacteria developed; then resistance resulted from gyrA D87G and gyrB E466D mutations and/or in other active efflux pumps besides AcrAB-TolC. For ST, ramA expression increased rapidly along with gyrA D87 N and/or gyrB S464F mutations. In conclusion, persistent use of ciprofloxacin may aggravate the resistance of different S. enterica serovars and prudent use of the fluoroquinolones is needed. The quicker resistance and higher mutation frequency of the SI isolates present a potential public health threat.

Identification by PCR of non-typhoidal Salmonella enterica serovars associated with invasive infections among febrile patients in Mali.

Directory of Open Access Journals (Sweden)

Sharon M Tennant

2010-03-01

Full Text Available In sub-Saharan Africa, non-typhoidal Salmonella (NTS are emerging as a prominent cause of invasive disease (bacteremia and focal infections such as meningitis in infants and young children. Importantly, including data from Mali, three serovars, Salmonella enterica serovar Typhimurium, Salmonella Enteritidis and Salmonella Dublin, account for the majority of non-typhoidal Salmonella isolated from these patients.We have extended a previously developed series of polymerase chain reactions (PCRs based on O serogrouping and H typing to identify Salmonella Typhimurium and variants (mostly I 4,[5],12:i:-, Salmonella Enteritidis and Salmonella Dublin. We also designed primers to detect Salmonella Stanleyville, a serovar found in West Africa. Another PCR was used to differentiate diphasic Salmonella Typhimurium and monophasic Salmonella Typhimurium from other O serogroup B, H:i serovars. We used these PCRs to blind-test 327 Salmonella serogroup B and D isolates that were obtained from the blood cultures of febrile patients in Bamako, Mali.We have shown that when used in conjunction with our previously described O-serogrouping PCR, our PCRs are 100% sensitive and specific in identifying Salmonella Typhimurium and variants, Salmonella Enteritidis, Salmonella Dublin and Salmonella Stanleyville. When we attempted to differentiate 171 Salmonella Typhimurium (I 4,[ 5],12:i:1,2 strains from 52 monophasic Salmonella Typhimurium (I 4,[5],12:i:- strains, we were able to correctly identify 170 of the Salmonella Typhimurium and 51 of the Salmonella I 4,[5],12:i:- strains.We have described a simple yet effective PCR method to support surveillance of the incidence of invasive disease caused by NTS in developing countries.

Molecular characterization, serotyping, and antibiotic susceptibility profile of Leptospira interrogans serovar Copenhageni isolates from Brazil

NARCIS (Netherlands)

Miraglia, Fabiana; Matsuo, Minekazo; Morais, Zenaide Maria; Dellagostin, Odir Antonio; Seixas, Fabiana Kömmling; Freitas, Julio César; Hartskeerl, Rudy; Moreno, Luisa Zanolli; Costa, Bárbara Letícia; Souza, Gisele Oliveira; Vasconcellos, Silvio Arruda; Moreno, Andrea Micke

2013-01-01

Leptospira interrogans serogroup Icterohaemorrhagiae is the major serogroup infecting humans worldwide, and rodents and dogs are the most significant transmission sources in urban environments. Knowledge of the prevalent serovars and their maintenance hosts is essential to understand the

pH-, Lactic acid-, and non-lactic acid-dependent activities of probiotic Lactobacilli against Salmonella enterica Serovar Typhimurium.

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Fayol-Messaoudi, Domitille; Berger, Cédric N; Coconnier-Polter, Marie-Hélène; Liévin-Le Moal, Vanessa; Servin, Alain L

2005-10-01

The mechanism(s) underlying the antibacterial activity of probiotic Lactobacillus strains appears to be multifactorial and includes lowering of the pH and the production of lactic acid and of antibacterial compounds, including bacteriocins and nonbacteriocin, non-lactic acid molecules. Addition of Dulbecco's modified Eagle's minimum essential medium to the incubating medium delays the killing activity of lactic acid. We found that the probiotic strains Lactobacillus johnsonii La1, Lactobacillus rhamnosus GG, Lactobacillus casei Shirota YIT9029, L. casei DN-114 001, and L. rhamnosus GR1 induced a dramatic decrease in the viability of Salmonella enterica serovar Typhimurium SL1344 mainly attributable to non-lactic acid molecule(s) present in the cell-free culture supernatant (CFCS). These molecules were more active against serovar Typhimurium SL1344 in the exponential growth phase than in the stationary growth phase. We also showed that the production of the non-lactic acid substance(s) responsible for the killing activity was dependent on growth temperature and that both unstable and stable substances with killing activity were present in the CFCSs. We found that the complete inhibition of serovar Typhimurium SL1344 growth results from a pH-lowering effect.

Production and characterization of monoclonal antibodies to the edta extract of Leptospira interrogans, serovar icterohaemorrhagiae

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Lilian Terezinha de Queiroz Leite

1996-10-01

Full Text Available Monoclonal antibodies (MABs ivere produced against an etbylenediaminetetraacetate (EDTA extract of Leptospira interrogans serovar icterohaemorrhagiae being characterized by gel precipitation as IgM and IgG (IgGl and IgG2b. The EDTA extract was detected as several bands by silver staining in SDS-PAGE. In the Western blot the bands around 20 KDa reacted with a monoclonal antibody, 47B4D6, and was oxidized by periodate and was not digested by pronase, suggesting that the determinant is of carbohydrate nature, lmmunocytochemistry, using colloidal gold labeling, showed that an EDTA extract determinant recognized by monoclonal antibody 47B4D6, is localized under the outer envelope of serovar icterohaemorrhagiae. Hoe AIAB raised against the EDTA extract was not able to protect hamsters from lethal challenge with virulent homologous leptospires.

Interferon-driven alterations of the host's amino acid metabolism in the pathogenesis of typhoid fever.

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Blohmke, Christoph J; Darton, Thomas C; Jones, Claire; Suarez, Nicolas M; Waddington, Claire S; Angus, Brian; Zhou, Liqing; Hill, Jennifer; Clare, Simon; Kane, Leanne; Mukhopadhyay, Subhankar; Schreiber, Fernanda; Duque-Correa, Maria A; Wright, James C; Roumeliotis, Theodoros I; Yu, Lu; Choudhary, Jyoti S; Mejias, Asuncion; Ramilo, Octavio; Shanyinde, Milensu; Sztein, Marcelo B; Kingsley, Robert A; Lockhart, Stephen; Levine, Myron M; Lynn, David J; Dougan, Gordon; Pollard, Andrew J

2016-05-30

Enteric fever, caused by Salmonella enterica serovar Typhi, is an important public health problem in resource-limited settings and, despite decades of research, human responses to the infection are poorly understood. In 41 healthy adults experimentally infected with wild-type S. Typhi, we detected significant cytokine responses within 12 h of bacterial ingestion. These early responses did not correlate with subsequent clinical disease outcomes and likely indicate initial host-pathogen interactions in the gut mucosa. In participants developing enteric fever after oral infection, marked transcriptional and cytokine responses during acute disease reflected dominant type I/II interferon signatures, which were significantly associated with bacteremia. Using a murine and macrophage infection model, we validated the pivotal role of this response in the expression of proteins of the host tryptophan metabolism during Salmonella infection. Corresponding alterations in tryptophan catabolites with immunomodulatory properties in serum of participants with typhoid fever confirmed the activity of this pathway, and implicate a central role of host tryptophan metabolism in the pathogenesis of typhoid fever. © 2016 Blohmke et al.

Interferon-driven alterations of the host’s amino acid metabolism in the pathogenesis of typhoid fever

Science.gov (United States)

Jones, Claire; Waddington, Claire S.; Zhou, Liqing; Hill, Jennifer; Clare, Simon; Mukhopadhyay, Subhankar; Schreiber, Fernanda; Roumeliotis, Theodoros I.; Yu, Lu; Ramilo, Octavio; Sztein, Marcelo B.; Kingsley, Robert A.; Levine, Myron M.

2016-01-01

Enteric fever, caused by Salmonella enterica serovar Typhi, is an important public health problem in resource-limited settings and, despite decades of research, human responses to the infection are poorly understood. In 41 healthy adults experimentally infected with wild-type S. Typhi, we detected significant cytokine responses within 12 h of bacterial ingestion. These early responses did not correlate with subsequent clinical disease outcomes and likely indicate initial host–pathogen interactions in the gut mucosa. In participants developing enteric fever after oral infection, marked transcriptional and cytokine responses during acute disease reflected dominant type I/II interferon signatures, which were significantly associated with bacteremia. Using a murine and macrophage infection model, we validated the pivotal role of this response in the expression of proteins of the host tryptophan metabolism during Salmonella infection. Corresponding alterations in tryptophan catabolites with immunomodulatory properties in serum of participants with typhoid fever confirmed the activity of this pathway, and implicate a central role of host tryptophan metabolism in the pathogenesis of typhoid fever. PMID:27217537

Serodiagnosis of Acute Typhoid Fever in Nigerian Pediatric Cases by Detection of Serum IgA and IgG Against Hemolysin E and Lipopolysaccharide.

Science.gov (United States)

Davies, D Huw; Jain, Aarti; Nakajima, Rie; Liang, Li; Jasinskis, Algis; Supnet, Medalyn; Felgner, Philip L; Teng, Andy; Pablo, Jozelyn; Molina, Douglas M; Obaro, Stephen K

2016-08-03

Inexpensive, easy-to-use, and highly sensitive diagnostic tests are currently unavailable for typhoid fever. To identify candidate serodiagnostic markers, we have probed microarrays displaying the full Salmonella enterica serovar Typhi (S. Typhi) proteome of 4,352 different proteins + lipopolysaccharides (LPSs), with sera from Nigerian pediatric typhoid and other febrile cases, Nigerian healthy controls, and healthy U.S. adults. Nigerian antibody profiles were broad (∼500 seropositive antigens) and mainly low level, with a small number of stronger "hits," whereas the profile in U.S. adults was typhoid cases. The response to LPS was also a strong discriminator of healthy controls and typhoid, although LPS did not discriminate between typhoid and nontyphoidal Salmonella (NTS) disease. As a first step toward the development of a point-of-care diagnostic, t1477 and LPS were evaluated on immunostrips. Both provided good discrimination between healthy controls and typhoid/NTS disease. Such a test could provide a useful screen for salmonellosis (typhoid and NTS disease) in suspected pediatric cases that present with undefined febrile disease. © The American Society of Tropical Medicine and Hygiene.

Cellulitis Due to Salmonella infantis.

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Satish R Patil

2013-01-01

Full Text Available Bacteria of the genus Salmonella are highly adapted for the growth in both humans and animals and cause a wide spectrum of disease. The growth of Serotypes S. typhi and S. paratyphi is restricted to human hosts, in whom these organisms cause enteric (typhoid fever. The remaining Serotypes (non typhoidal Salmonella or NTS can colonize the gastrointestinal tracts of the broad range of animals, including mammals, reptiles, birds and insects. The usual clinical presentation of non-typhoidal salmonellae (NTS infection is self limited gastroenteritis; however bacteremia and focal extra intestinal infection may occur. However salmonella localization to the skin presenting as cutaneous ulceration is regarded as a rare event. Rates of morbidity and mortality associated with NTS are highest among the elderly, infants, and immunocompromised individuals, including those with hemoglobinopathies, HIV infection, or infections that cause blockade of the reticuloendothelial system. We isolated S.infantis in 50 years old man with left leg cellulitis. The serotype was confirmed at Central Research Institute, Kasauli.

Resistance Patterns of Typhoid Fever in Children: A Longitudinal Community-Based Study.

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Vala, Snehal; Shah, Urvesh; Ahmad, Syed Amir; Scolnik, Dennis; Glatstein, Miguel

2016-01-01

Salmonella typhi and S. paratyphi are important causes of bacteremia in children, especially those from the developing world. There is a lack of standardized treatment protocols for such patients in the literature, and there are also reports of therapeutic failure related to resistance to commonly used antibiotics. We analyzed the epidemiological, clinical, and antimicrobiological sensitivity patterns of disease in patients diagnosed with blood culture-positive typhoid fever over a 6-month period in a tertiary-care pediatric hospital in western India. Data were retrospectively analyzed for all patients with Salmonella isolates on blood culture between January 1 and June 30, 2011 at the Synergy Neonatal and Pediatric Hospital. Susceptibility of isolates to antimicrobials and minimum inhibitory concentrations were determined. Demographic data, symptoms and signs, basic laboratory results, treatment courses, and clinical outcomes were collected from clinical charts. All of the 61 isolates of S. typhi were sensitive to cefepime (fourth-generation cephalosporin), 96% to third-generation cephalosporins, and 95% to quinolones. There was intermediate sensitivity to ampicillin (92%) and chloramphenicol (80%). Notably, azithromycin resistance was observed in 63% of isolates. All patients ultimately made full recoveries. There is an urgent need for large scale, community-based clinical trials to evaluate the effectiveness of different antibiotics in enteric fever. Our antimicrobial susceptibility data suggest that quinolones and third-generation cephalosporins should be used as first-line antimicrobials in enteric fever. Although fourth-generation cephalosporins are useful, we feel their use should be restricted to complicated or resistant cases.

Leptospira interrogans serovar copenhageni harbors two lexA genes involved in SOS response.

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Luciane S Fonseca

Full Text Available Bacteria activate a regulatory network in response to the challenges imposed by DNA damage to genetic material, known as the SOS response. This system is regulated by the RecA recombinase and by the transcriptional repressor lexA. Leptospira interrogans is a pathogen capable of surviving in the environment for weeks, being exposed to a great variety of stress agents and yet retaining its ability to infect the host. This study aims to investigate the behavior of L. interrogans serovar Copenhageni after the stress induced by DNA damage. We show that L. interrogans serovar Copenhageni genome contains two genes encoding putative LexA proteins (lexA1 and lexA2 one of them being potentially acquired by lateral gene transfer. Both genes are induced after DNA damage, but the steady state levels of both LexA proteins drop, probably due to auto-proteolytic activity triggered in this condition. In addition, seven other genes were up-regulated following UV-C irradiation, recA, recN, dinP, and four genes encoding hypothetical proteins. This set of genes is potentially regulated by LexA1, as it showed binding to their promoter regions. All these regions contain degenerated sequences in relation to the previously described SOS box, TTTGN 5CAAA. On the other hand, LexA2 was able to bind to the palindrome TTGTAN10TACAA, found in its own promoter region, but not in the others. Therefore, the L. interrogans serovar Copenhageni SOS regulon may be even more complex, as a result of LexA1 and LexA2 binding to divergent motifs. New possibilities for DNA damage response in Leptospira are expected, with potential influence in other biological responses such as virulence.

Complete Whole-Genome Sequence of Salmonella enterica subsp. enterica Serovar Java NCTC5706.

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Fazal, Mohammed-Abbas; Alexander, Sarah; Burnett, Edward; Deheer-Graham, Ana; Oliver, Karen; Holroyd, Nancy; Parkhill, Julian; Russell, Julie E

2016-11-03

Salmonellae are a significant cause of morbidity and mortality globally. Here, we report the first complete genome sequence for Salmonella enterica subsp. enterica serovar Java strain NCTC5706. This strain is of historical significance, having been isolated in the pre-antibiotic era and was deposited into the National Collection of Type Cultures in 1939. © Crown copyright 2016.

Tetracycline promotes the expression of ten fimbrial operons in specific Salmonella enterica serovar Typhimurium isolates

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Multidrug-resistant (MDR) Salmonella is associated with increased morbidity in humans and presents an important food safety concern. Antibiotic resistance among isolates of Salmonella enterica serovar Typhimurium has become especially prevalent as over 27 per cent of isolates from humans in the Unit...

Survival of Salmonella enterica serovar infantis on and within stored table eggs.

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Lublin, Avishai; Maler, Ilana; Mechani, Sara; Pinto, Riky; Sela-Saldinger, Shlomo

2015-02-01

Contaminated table eggs are considered a primary source of foodborne salmonellosis globally. Recently, a single clone of Salmonella enterica serovar Infantis emerged in Israel and became the predominant serovar isolated in poultry. This clone is currently the most prevalent strain in poultry and is the leading cause of salmonellosis in humans. Because little is known regarding the potential transmission of this strain from contaminated eggs to humans, the objective of this study was to evaluate the ability of Salmonella Infantis to survive on the eggshell or within the egg during cold storage or at room temperature. Salmonella cells (5.7 log CFU per egg) were inoculated on the surface of 120 intact eggs or injected into the egg yolk (3.7 log CFU per egg) of another 120 eggs. Half of the eggs were stored at 5.5 ± 0.3°C and half at room temperature (25.5 ± 0.1°C) for up to 10 weeks. At both temperatures, the number of Salmonella cells on the shell declined by 2 log up to 4 weeks and remained constant thereafter. Yolk-inoculated Salmonella counts at cold storage declined by 1 log up to 4 weeks and remained constant, while room-temperature storage supported the growth of the pathogen to a level of 8 log CFU/ml of total egg content, as early as 4 weeks postinoculation. Examination of egg content following surface inoculation revealed the presence of Salmonella in a portion of the eggs at both temperatures up to 10 weeks, suggesting that this strain can also penetrate through the shell and survive within the egg. These findings imply that Salmonella enterica serovar Infantis is capable of survival both on the exterior and interior of table eggs and even multiply inside the egg at room temperature. Our findings support the need for prompt refrigeration to prevent Salmonella multiplication during storage of eggs at room temperature.

Genome and transcriptome adaptation accompanying emergence of the definitive type 2 host-restricted Salmonella enterica serovar Typhimurium pathovar.

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Kingsley, Robert A; Kay, Sally; Connor, Thomas; Barquist, Lars; Sait, Leanne; Holt, Kathryn E; Sivaraman, Karthi; Wileman, Thomas; Goulding, David; Clare, Simon; Hale, Christine; Seshasayee, Aswin; Harris, Simon; Thomson, Nicholas R; Gardner, Paul; Rabsch, Wolfgang; Wigley, Paul; Humphrey, Tom; Parkhill, Julian; Dougan, Gordon

2013-08-27

Salmonella enterica serovar Typhimurium definitive type 2 (DT2) is host restricted to Columba livia (rock or feral pigeon) but is also closely related to S. Typhimurium isolates that circulate in livestock and cause a zoonosis characterized by gastroenteritis in humans. DT2 isolates formed a distinct phylogenetic cluster within S. Typhimurium based on whole-genome-sequence polymorphisms. Comparative genome analysis of DT2 94-213 and S. Typhimurium SL1344, DT104, and D23580 identified few differences in gene content with the exception of variations within prophages. However, DT2 94-213 harbored 22 pseudogenes that were intact in other closely related S. Typhimurium strains. We report a novel in silico approach to identify single amino acid substitutions in proteins that have a high probability of a functional impact. One polymorphism identified using this method, a single-residue deletion in the Tar protein, abrogated chemotaxis to aspartate in vitro. DT2 94-213 also exhibited an altered transcriptional profile in response to culture at 42°C compared to that of SL1344. Such differentially regulated genes included a number involved in flagellum biosynthesis and motility. IMPORTANCE Whereas Salmonella enterica serovar Typhimurium can infect a wide range of animal species, some variants within this serovar exhibit a more limited host range and altered disease potential. Phylogenetic analysis based on whole-genome sequences can identify lineages associated with specific virulence traits, including host adaptation. This study represents one of the first to link pathogen-specific genetic signatures, including coding capacity, genome degradation, and transcriptional responses to host adaptation within a Salmonella serovar. We performed comparative genome analysis of reference and pigeon-adapted definitive type 2 (DT2) S. Typhimurium isolates alongside phenotypic and transcriptome analyses, to identify genetic signatures linked to host adaptation within the DT2 lineage.

Salmonella enterica serovars Typhimurium and Enteritidis causing mixed infections in febrile children in Mozambique

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García V

2018-01-01

Full Text Available Vanesa García,1 Inácio Mandomando,2,3 Joaquim Ruiz,4 Silvia Herrera-León,5 Pedro L Alonso,3,4 M Rosario Rodicio1 1Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, Oviedo, Spain; 2Centro de Investigação em Saúde de Manhiça, 3Instituto Nacional de Saúde, Ministério da Saúde, Maputo, Mozambique; 4ISGlobal, Barcelona Centre for International Health Research, Hospital Clínic, Universitat de Barcelona, Barcelona, 5Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain Background and purpose: Invasive nontyphoidal salmonellosis, mostly caused by serovars Typhimurium and Enteritidis of Salmonella enterica, has emerged as a major public health problem in sub-Saharan Africa. The aim of this study was the clinical and microbiological characterization of nontyphoidal salmonellosis episodes affecting febrile children in Mozambique. Patients and methods: The clinical records of the patients were evaluated, and S. enterica isolates were characterized with regard to serovar, phage type, antimicrobial resistance (phenotype/responsible genes, plasmid content, pulsed-field gel electrophoresis, and multilocus sequence typing. Results: Fifteen S. Typhimurium and 21 S. Enteritidis isolates were recovered from blood samples of 25 children, the majority with underlying risk factors. With regard to phage typing, most isolates were either untypeable or reacted but did not conform, revealing that a number of previously unrecognized patterns are circulating in Mozambique. Most isolates were multidrug-resistant, with nearly all of the responsible genes located on derivatives of serovar-specific virulence plasmids. ST313 and ST11 were the predominant sequence types associated with S. Typhimurium and S. Enteritidis, respectively, and the uncommon ST1479 was also detected in S. Enteritidis. A distinct XbaI fragment of ~350 kb was associated with pulsed-field gel electrophoresis patterns of

Comparison of Chlamydia trachomatis serovar L2 growth in polarized genital epithelial cells grown in three-dimensional culture with non-polarized cells.

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Dessus-Babus, Sophie; Moore, Cheryl G; Whittimore, Judy D; Wyrick, Priscilla B

2008-04-01

A common model for studying Chlamydia trachomatis and growing chlamydial stocks uses Lymphogranuloma venereum serovar L2 and non-polarized HeLa cells. However, recent publications indicate that the growth rate and progeny yields can vary considerably for a particular strain depending on the cell line/type used, and seem to be partially related to cell tropism. In the present study, the growth of invasive serovar L2 was compared in endometrial HEC-1B and endocervical HeLa cells polarized on collagen-coated microcarrier beads, as well as in HeLa cells grown in tissue culture flasks. Microscopy analysis revealed no difference in chlamydial attachment/entry patterns or in inclusion development throughout the developmental cycle between cell lines. Very comparable growth curves in both cell lines were also found using real-time PCR analysis, with increases in chlamydial DNA content of 400-500-fold between 2 and 36 h post-inoculation. Similar progeny yields with comparable infectivity were recovered from HEC-1B and HeLa cell bead cultures, and no difference in chlamydial growth was found in polarized vs. non-polarized HeLa cells. In conclusion, unlike other C. trachomatis strains such as urogenital serovar E, invasive serovar L2 grows equally well in physiologically different endometrial and endocervical environments, regardless of the host cell polarization state.

The use of serological titres of IgA and IgG in (early) discrimination between rectal infection with non-lymphogranuloma venereum and lymphogranuloma venereum serovars of Chlamydia trochomotis

NARCIS (Netherlands)

E.M. van der Snoek (Eric); J.M. Ossewaarde (Jacobus); W.I. van der Meijden (Willem); P.G.H. Mulder (Paul); H.B. Thio (Bing)

2007-01-01

textabstractObjectives: To investigate whether serological titres of species-specific IgA and IgG antibodies in patients with rectal chlamydial infection could discriminate between infection with serovar L2 lymphogranuloma venereum (LGV) and infection with non-LGV serovars. Methods: A total of 39

Comparison of agglutinating and neutralizing antibodies to serovar hardjo in sows immunized with two commercial whole culture polivalent anti-leptospira bacterins

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Soto, Francisco Rafael Martins; Pinheiro, Sônia Regina; Morais, Zenaide Maria; Gonçales, Amane Paldês; de Azevedo, Sérgio Santos; Bernardi, Fernanda; Camargo, Sebastião Rodrigues; Vasconcellos, Silvio Arruda

2008-01-01

It was performed the comparison of the intensity and duration of agglutinating and neutralizing antibodies to serovar Hardjo in swines vaccinated with two commercial anti-leptospira bacterins. Sows no reactive to 24 Leptospira sp serovars in the microscopic agglutination test (MAT) were divided in three groups: Group A (n=08): received two vaccine A doses with 30 days interval, Group B (n=08) two vaccine B doses with 30 days interval and Group C (n=08): control no vaccinated against leptospirosis.Blood samples were collected each 30 days during six months following the first vaccination. The sera were tested by MAT and growth inhibition test (GIT) to serovar Hardjo in order to evaluate respectively agglutinating and neutralizing antibodies. It was found that neutralizing antibodies persisted for a longer time than the agglutinating ones and that the absence of agglutinating antibodies does not means in the absence of the neutralizing. The peaks of agglutinating antibodies was obtained at least 30 days earlier than that produced by neutralizing. The duration of both kinds of antibodies measured differed between the two bacterines tested. The period for inducing neutralizing antibodies against serovar Hardjo indicated that gilts must be immunized with two doses of whole culture anti-leptospira bacterines applied 30 days each other at least 90 days before the first mating. For the maintenance of hight levels of neutralizing antibodies the revaccinations must be performed every six months after the first vaccination. PMID:24031250

Genomic and Phenotypic Analyses Reveal the Emergence of an Atypical Salmonella enterica Serovar Senftenberg Variant in China

KAUST Repository

Abd El Ghany, Moataz; Shi, Xiaolu; Li, Yinghui; Ansari, Hifzur Rahman; Hill-Cawthorne, Grant A.; Ho, Y. S.; Naeem, Raeece; Pickard, Derek; Klena, John D.; Xu, Xuebing; Pain, Arnab; Hu, Qinghua

2016-01-01

Human infections with Salmonella enterica subspecies enterica serovar Senftenberg are often associated with exposure to poultry flocks, farm environments, or contaminated food. The recent emergence of multidrug-resistant isolates has raised public

Comparison of Chlamydia trachomatis serovar L2 growth in polarized genital epithelial cells grown in three-dimensional culture with non-polarized cells

OpenAIRE

Dessus-Babus, Sophie; Moore, Cheryl G.; Whittimore, Judy D.; Wyrick, Priscilla B.

2008-01-01

A common model for studying Chlamydia trachomatis and growing chlamydial stocks uses Lymphogranuloma venereum serovar L2 and non-polarized HeLa cells. However, recent publications indicate that the growth rate and progeny yields can vary considerably for a particular strain depending on the cell line/type used, and seem to be partially related to cell tropism. In the present study, the growth of invasive serovar L2 was compared in endometrial HEC-1B and endocervical HeLa cells polarized on co...

Factors Associated with Non-typhoidal Salmonella Bacteremia versus Typhoidal Salmonella Bacteremia in Patients Presenting for Care in an Urban Diarrheal Disease Hospital in Bangladesh.

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K M Shahunja

Full Text Available Non-typhoidal Salmonella (NTS and Salmonella enterica serovar Typhi bacteremia are the causes of significant morbidity and mortality worldwide. There is a paucity of data regarding NTS bacteremia in South Asia, a region with a high incidence of typhoidal bacteremia. We sought to determine clinical predictors and outcomes associated with NTS bacteremia compared with typhoidal bacteremia.We performed a retrospective age-matched case-control study of patients admitted to the Dhaka Hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh, between February 2009 and March 2013. We compared demographic, clinical, microbiological, and outcome variables of NTS bacteremic patients with age-matched S. Typhi bacteremic patients, and a separate comparison of patients with NTS bacteremia and patients with NTS gastroenteritis.Of 20 patients with NTS bacteremia, 5 died (25% case fatality, compared to none of 60 age-matched cases of S. Typhi bacteremia. In univariate analysis, we found that compared with S. Typhi bacteremia, cases of NTS bacteremia had more severe acute malnutrition (SAM in children under five years of age, less often presented with a duration of fever ≥ 5 days, and were more likely to have co-morbidities on admission such as pneumonia and clinical signs of sepsis (p<0.05 in all cases. In multivariable logistic regression, SAM, clinical sepsis, and pneumonia were independent risk factors for NTS bacteremia compared with S. Typhi bacteremia (p<0.05 in all cases. Notably, we found marked differences in antibiotic susceptibilities, including NTS strains resistant to antibiotics commonly used for empiric therapy of patients suspected to have typhoid fever.Diarrheal patients with NTS bacteremia more often presented with co-morbidities and had a higher case fatality rate compared to those with typhoidal bacteremia. Clinicians in regions where both typhoid and NTS bacteremia are prevalent need to be vigilant about the

A cross-sectional seroepidemiological survey of typhoid fever in Fiji.

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Conall H Watson

2017-07-01

Full Text Available Fiji, an upper-middle income state in the Pacific Ocean, has experienced an increase in confirmed case notifications of enteric fever caused by Salmonella enterica serovar Typhi (S. Typhi. To characterize the epidemiology of typhoid exposure, we conducted a cross-sectional sero-epidemiological survey measuring IgG against the Vi antigen of S. Typhi to estimate the effect of age, ethnicity, and other variables on seroprevalence. Epidemiologically relevant cut-off titres were established using a mixed model analysis of data from recovering culture-confirmed typhoid cases. We enrolled and assayed plasma of 1787 participants for anti-Vi IgG; 1,531 of these were resident in mainland areas that had not been previously vaccinated against S. Typhi (seropositivity 32.3% (95%CI 28.2 to 36.3%, 256 were resident on Taveuni island, which had been previously vaccinated (seropositivity 71.5% (95%CI 62.1 to 80.9%. The seroprevalence on the Fijian mainland is one to two orders of magnitude higher than expected from confirmed case surveillance incidence, suggesting substantial subclinical or otherwise unreported typhoid. We found no significant differences in seropositivity prevalences by ethnicity, which is in contrast to disease surveillance data in which the indigenous iTaukei Fijian population are disproportionately affected. Using multivariable logistic regression, seropositivity was associated with increased age (odds ratio 1.3 (95% CI 1.2 to 1.4 per 10 years, the presence of a pit latrine (OR 1.6, 95%CI 1.1 to 2.3 as opposed to a septic tank or piped sewer, and residence in settlements rather than residential housing or villages (OR 1.6, 95% CI 1.0 to 2.7. Increasing seropositivity with age is suggestive of low-level endemic transmission in Fiji. Improved sanitation where pit latrines are used and addressing potential transmission routes in settlements may reduce exposure to S. Typhi. Widespread unreported infection suggests there may be a role for typhoid

A cross-sectional seroepidemiological survey of typhoid fever in Fiji.

Science.gov (United States)

Watson, Conall H; Baker, Stephen; Lau, Colleen L; Rawalai, Kitione; Taufa, Mere; Coriakula, Jerimaia; Thieu, Nga Tran Vu; Van, Tan Trinh; Ngoc, Dung Tran Thi; Hens, Niel; Lowry, John H; de Alwis, Ruklanthi; Cano, Jorge; Jenkins, Kylie; Mulholland, E Kim; Nilles, Eric J; Kama, Mike; Edmunds, W John

2017-07-01

Fiji, an upper-middle income state in the Pacific Ocean, has experienced an increase in confirmed case notifications of enteric fever caused by Salmonella enterica serovar Typhi (S. Typhi). To characterize the epidemiology of typhoid exposure, we conducted a cross-sectional sero-epidemiological survey measuring IgG against the Vi antigen of S. Typhi to estimate the effect of age, ethnicity, and other variables on seroprevalence. Epidemiologically relevant cut-off titres were established using a mixed model analysis of data from recovering culture-confirmed typhoid cases. We enrolled and assayed plasma of 1787 participants for anti-Vi IgG; 1,531 of these were resident in mainland areas that had not been previously vaccinated against S. Typhi (seropositivity 32.3% (95%CI 28.2 to 36.3%)), 256 were resident on Taveuni island, which had been previously vaccinated (seropositivity 71.5% (95%CI 62.1 to 80.9%)). The seroprevalence on the Fijian mainland is one to two orders of magnitude higher than expected from confirmed case surveillance incidence, suggesting substantial subclinical or otherwise unreported typhoid. We found no significant differences in seropositivity prevalences by ethnicity, which is in contrast to disease surveillance data in which the indigenous iTaukei Fijian population are disproportionately affected. Using multivariable logistic regression, seropositivity was associated with increased age (odds ratio 1.3 (95% CI 1.2 to 1.4) per 10 years), the presence of a pit latrine (OR 1.6, 95%CI 1.1 to 2.3) as opposed to a septic tank or piped sewer, and residence in settlements rather than residential housing or villages (OR 1.6, 95% CI 1.0 to 2.7). Increasing seropositivity with age is suggestive of low-level endemic transmission in Fiji. Improved sanitation where pit latrines are used and addressing potential transmission routes in settlements may reduce exposure to S. Typhi. Widespread unreported infection suggests there may be a role for typhoid

Epidemiological investigation of Salmonella enterica serovar Kedougou in Thailand.

Science.gov (United States)

Pornruangwong, Srirat; Hendriksen, Rene S; Pulsrikarn, Chaiwat; Bangstrakulnonth, Aroon; Mikoleit, Matthew; Davies, Rob H; Aarestrup, Frank M; Garcia-Migura, Lourdes

2011-02-01

Salmonella enterica serovar Kedougou is among the top 10 serovars reported in northern Thailand. The objective of this study was to identify risk factors associated with Salmonella Kedougou infection in Thailand and to compare the molecular types and antimicrobial resistance with Salmonella Kedougou isolates of human origin from United States and of animal origin from the United Kingdom. Data from 13,976 Salmonella infections of which 253 were Salmonella Kedougou collected in Thailand between 2002 and 2008 were analyzed by logistic regression. Antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE) were performed on selected Salmonella Kedougou strains causing infections in Thailand (n = 66), and compared to isolates from the United States (n = 5) and the United Kingdom (n = 20). Logistic analysis revealed season (hot/dry; p = 0.023), region (northern Thailand; p Thailand were resistant to third-generation cephalosporins: two harbored bla(CTX-M-63) and one bla(CMY-2). PFGE revealed 45 unique clusters. Isolates obtained from humans in Thailand and the United States presented identical PFGE profiles suggesting a travel association, whereas the majority of the animal isolates from United Kingdom clustered separately. This study reveals Salmonella Kedougou as a major cause of human infections in northern Thailand especially during the hot period and suggests a global spread probably due to travel. The clonal types causing infections in humans differed from those observed in animals in United Kingdom, which suggests the absence of an epidemiological link and could suggest differences in virulence. The high frequency of antimicrobial resistance, including emergence of resistance to fluoroquinolones and third-generation cephalosporins, might pose problems for treatment of infections.

Serovars of Salmonella isolated from Danish turkeys between 1995 and 2000 and their antimicrobial resistance

DEFF Research Database (Denmark)

Pedersen, Karl; Hansen, H.C.; Jørgensen, J.C.

2002-01-01

, florfenicol, or amoxycillin with clavulanic acid, only 24 isolates were resistant to two or more compounds in various combinations of up to six compounds; one Salmonella Havana isolate was resistant to six compounds. Six isolates were serovar Typhimurium, but none of them belonged to phage type DT104....

Epidemiology of a Salmonella enterica subsp. Enterica serovar Typhimurium strain associated with a songbird outbreak.

Science.gov (United States)

Blehert, David S.; Hernandez, Sonia M.; Keel, Kevin; Sanchez, Susan; Trees, Eija; ,

2012-01-01

Salmonella enterica subsp. enterica serovar Typhimurium is responsible for the majority of salmonellosis cases worldwide. This Salmonella serovar is also responsible for die-offs in songbird populations. In 2009, there was an S. Typhimurium epizootic reported in pine siskins in the eastern United States. At the time, there was also a human outbreak with this serovar that was associated with contaminated peanuts. As peanuts are also used in wild-bird food, it was hypothesized that the pine siskin epizootic was related to this human outbreak. A comparison of songbird and human S. Typhimurium pulsed-field gel electrophoresis (PFGE) patterns revealed that the epizootic was attributed not to the peanut-associated strain but, rather, to a songbird strain first characterized from an American goldfinch in 1998. This same S. Typhimurium strain (PFGE type A3) was also identified in the PulseNet USA database, accounting for 137 of 77,941 total S. Typhimurium PFGE entries. A second molecular typing method, multiple-locus variable-number tandem-repeat analysis (MLVA), confirmed that the same strain was responsible for the pine siskin epizootic in the eastern United States but was distinct from a genetically related strain isolated from pine siskins in Minnesota. The pine siskin A3 strain was first encountered in May 2008 in an American goldfinch and later in a northern cardinal at the start of the pine siskin epizootic. MLVA also confirmed the clonal nature of S. Typhimurium in songbirds and established that the pine siskin epizootic strain was unique to the finch family. For 2009, the distribution of PFGE type A3 in passerines and humans mirrored the highest population density of pine siskins for the East Coast.

Laboratory surveillance of Salmonella enterica from human clinical cases in Colombia 2005-2011.

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Rodríguez, Edna Catering; Díaz-Guevara, Paula; Moreno, Jaime; Bautista, Adriana; Montaño, Lucy; Realpe, María Elena; Della Gaspera, Anabella; Wiesner, Magdalena

Salmonella is an enteropathogen acquired through contaminated food or water. In Colombia, Salmonella spp. is included in the national surveillance of Acute Diarrhoeal Diseases and typhoid fever initiated in 1997. This report shows the phenotype and genotype results obtained from 2005 to 2011. A total of 4010 isolates of Salmonella enterica were analysed by serotyping with Kauffmann-White-LeMinor, antimicrobial resistance patterns, and pulse-field gel electrophoresis (PFGE). A total of 93 serovars were identified, of which, Typhimurium, Enteritidis, Typhi, Dublin, Panama, Derby, Braenderup, Saintpaul, and Uganda were prominent. The highest levels of resistance were found for tetracycline and nalidixic acid. Susceptibility was observed in 52.4% (2101/4010) of the isolates. Multi-resistance was recorded in 54.9% of Typhimurium isolates, with 81 different combinations. Using PFGE, 51.9% (2083/4010) isolates were analysed in 34 serovars, and 828 electrophoretic patterns were obtained. From these, 8 patterns were found in at least two Latin-American countries. The surveillance of Salmonella spp. provides information on the serovar distribution, antimicrobial resistance, and clonal distribution in Colombia, as well as information to treat this disease and control the spread of antimicrobial bacterial resistance. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Microscopic agglutination test on captive rattlesnakes : Data on serovars and titers

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T.C.S. Rodrigues

2016-06-01

Full Text Available The microscopic agglutination test (MAT is considered the “golden standard” leptospirosis serodiagnostic test, but there is little information about it as it pertains to snakes. To fill this information gap, we provide data on serovars and titers of fifty-six Crotalus durissus collilineatus sera samples that tested positive by MAT (10.1016/j.actatropica.2016.02.006 (Rodrigues et al., 2016 [5]. These data are presented in a table, along with a description of the methodology used for sample collection and serologic testing.

A functional cra gene is required for Salmonella enterica serovar typhimurium virulence in BALB/c mice

DEFF Research Database (Denmark)

Allen, J. H.; Utley, M.; Van den Bosch, H.

2000-01-01

A minitransposon mutant of Salmonella enterica serovar Typhimurium SR-11, SR-11 Fad(-), is unable to utilize gluconeogenic substrates as carbon sources and is avirulent and immunogenic when administered perorally to BALB/c mice (M. J. Utley et al., FEMS Microbiol. Lett., 163:129-134, 1998). Here,...

Relationship between S. typhi R plasmid (pRST98) and macrophage apoptosis

International Nuclear Information System (INIS)

Song Guorong; Wu Shuyan; Li Yuanyuan; Lv Jie; Xu Yang; Huang Rui

2008-01-01

Objective: To study the relationship between S. typhi R plasmid (pR ST98 ) and macrophage apoptosis. Methods: pR ST98 was transferred into a less virulent strain of S. typhimurium for creating a transconjugant pR ST98 /RIA, the standard S. typhimurium virulence strain SR-11 was used as the positive control, and RIA as the negative one. Infection with murine macrophage J 774A.1 occurred separately under the same conditions. J 774A.1 apoptosis was detected by flow cytometry and TUNEL at 0, 2, 4, 6, 12, 24 hours respectively. Mitochondria membrane potential was detected by JC-1 staining method. Viable bacteria was detected by serial dilution at the same time and viable cells stained with Trypan blue were counted. Results: SR-11 results in a higher apoptosis in J 774A.1 than pR ST98 /RIA, and a combined pR ST98 /RIA higher than RIA (P pR ST98 /RIA>SR-11 (P ST98 could increase the macrophage apoptosis. (authors)

Preliminary Investigations on the Distribution of Leptospira Serovars in Domestic Animals in North-west Morocco.

Science.gov (United States)

Benkirane, A; Noury, S; Hartskeerl, R A; Goris, M G A; Ahmed, A; Nally, J E

2016-04-01

Leptospirosis is a neglected zoonosis of global importance with a complex epidemiology that affects humans, domestic and wild mammals. However, due to the diversity of clinical signs and difficulties of establishing a confirmatory laboratory diagnosis, the disease remains poorly investigated, particularly in the developing world. In Morocco, a descriptive study of the seroprevalence of Leptospira infection in animals has never been undertaken. To fill this gap, the current study was conducted on a subset of animals in north-west Morocco as a preliminary step towards understanding the epidemiological patterns of animal leptospirosis in the country. The study was conducted on 289 serum samples collected between January and April 2012 from dogs, cattle, sheep, goats and donkeys in the areas of Rabat-Temara, Sidi Kacem and Oulmes. All serum samples were tested by the MAT with 14 reference strains of the most prevalent pathogenic serovars of Leptospira and two serovars of non-pathogenic Leptospira. The overall seroprevalence of Leptospira in cattle, sheep, goats, dogs and donkeys was 15%, 18%, 20%, 21% and 20%, respectively. The most prevalent serogroups found in each species were Ballum, Sejroe, and Australis in cattle, Ballum, Australis and Sejroe in sheep, Australis and Ballum in goats, Javanica and Australis in donkey and Australis, Ballum and Canicola in dogs. Of all the serogroups tested in this study, Icterohaemorrhagiae, the only serogroup which has been previously reported in humans in Morocco, was rarely reactive. The majority of reactive sera were collected from low land areas. A large number of sera samples classified as seronegative when tested against pathogenic leptospires were positive when tested against non-pathogenic leptospires; this is suggestive of possible novel, as yet unclassified, Leptospira serovars in Morocco. Eleven of thirteen sheep urine samples were positive by real-time PCR confirming their role as Leptospira carriers in Morocco. © 2014

Antimicrobial activity of the bioactive components of essential oils from Pakistani spices against Salmonella and other multi-drug resistant bacteria

Science.gov (United States)

2013-01-01

Background The main objective of this study was the phytochemical characterization of four indigenous essential oils obtained from spices and their antibacterial activities against the multidrug resistant clinical and soil isolates prevalent in Pakistan, and ATCC reference strains. Methods Chemical composition of essential oils from four Pakistani spices cumin (Cuminum cyminum), cinnamon (Cinnamomum verum), cardamom (Amomum subulatum) and clove (Syzygium aromaticum) were analyzed on GC/MS. Their antibacterial activities were investigated by minimum inhibitory concentration (MIC) and Thin-Layer Chromatography-Bioautographic (TLC-Bioautographic) assays against pathogenic strains Salmonella typhi (D1 Vi-positive), Salmonella typhi (G7 Vi-negative), Salmonella paratyphi A, Escherichia coli (SS1), Staphylococcus aureus, Pseudomonas fluorescens and Bacillus licheniformis (ATCC 14580). The data were statistically analyzed by using Analysis of Variance (ANOVA) and Least Significant Difference (LSD) method to find out significant relationship of essential oils biological activities at p essential oils, oil from the bark of C. verum showed best antibacterial activities against all selected bacterial strains in the MIC assay, especially with 2.9 mg/ml concentration against S. typhi G7 Vi-negative and P. fluorescens strains. TLC-bioautography confirmed the presence of biologically active anti-microbial components in all tested essential oils. P. fluorescens was found susceptible to C. verum essential oil while E. coli SS1 and S. aureus were resistant to C. verum and A. subulatum essential oils, respectively, as determined in bioautography assay. The GC/MS analysis revealed that essential oils of C. cyminum, C. verum, A. subulatum, and S. aromaticum contain 17.2% cuminaldehyde, 4.3% t-cinnamaldehyde, 5.2% eucalyptol and 0.73% eugenol, respectively. Conclusions Most of the essential oils included in this study possessed good antibacterial activities against selected multi

Transcriptomic analysis of swarm motility phenotype of Salmonella enterica serovar Typhimurium mutant defective in periplasmic glucan synthesis

Science.gov (United States)

Movement of food-borne pathogens on moist surfaces enables them to migrate towards more favorable niches and facilitate their survival for extended periods of time. Salmonella enterica serovar Typhimurium mutants defective in OPG synthesis are unable to exhibit motility on moist surfaces (swarming) ...

Chlortetracycline and florfenicol induce expression of genes associated with pathogenicity in multidrug-resistant Salmonella enterica serovar Typhimurium

Science.gov (United States)

Background Multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium (S. Typhimurium) is a serious public health threat as infections caused by these strains are more difficult and expensive to treat. Livestock serve as a reservoir for MDR Salmonella, and the antibiotics chlortetracycline an...

Suitability of PCR fingerprinting, infrequent-restriction-site PCR, and pulsed-field gel electrophoresis, combined with computerized gel analysis, in library typing of Salmonella enterica serovar enteritidis

DEFF Research Database (Denmark)

Garaizar, J.; Lopez-Molina, N.; Laconcha, I.

2000-01-01

Strains of Salmonella enterica (n = 212) of different serovars and phage types were used to establish a library typing computerized system for serovar Enteritidis on the basis of PCR fingerprinting, infrequent-restriction-site PCR (IRS-PCR), or pulsed-field gel electrophoresis (PFGE). The rate...... showed an intercenter reproducibility value of 93.3%. The high reproducibility of PFGE combined with the previously determined high discrimination directed its use for library typing. The use of PFGE with enzymes XbaI, BlnI, and SpeI for library typing of serovar Enteritidis was assessed with GelCompar 4.......0 software, Three computer libraries of PFGE DNA profiles were constructed, and their ability to recognize new DNA profiles was analyzed. The results obtained pointed out that the combination of PFGE with computerized analysis could be suitable in long-term epidemiological comparison and surveillance...

Prevalence, Virulence Genes and Antimicrobial Resistance Profiles of Salmonella Serovars from Retail Beef in Selangor, Malaysia

Directory of Open Access Journals (Sweden)

Tze Y. Thung

2018-01-01

Full Text Available The aim of the present study was to investigate the prevalence of Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium in retail beef from different retail markets of Selangor area, as well as, to assess their pathogenic potential and antimicrobial resistance. A total of 240 retail beef meat samples (chuck = 60; rib = 60; round = 60; sirloin = 60 were randomly collected. The multiplex polymerase chain reaction (mPCR in combination with the most probable number (MPN method was employed to detect Salmonella spp., S. Enteritidis and S. Typhimurium in the meat samples. The prevalence of Salmonella spp., S. Enteritidis and S. Typhimurium in 240 beef meat samples were 7.50, 1.25, and 0.83%, respectively. The microbial loads of total Salmonella was found in the range of <3 to 15 MPN/g. Eight different serovars of Salmonella were identified among the 23 isolates, and S. Agona was the predominant serovar (26.09%. Interestingly, all the Salmonella isolates were resistant to penicillin, erythromycin and vancomycin, but the sensitivity was observed for tetracycline, gentamicin and amoxicillin/clavulanic acid. All 23 isolates were resistant to at least three antibiotics. Two S. Typhimurium isolates (8.70% exhibited the highest multiple antibiotic resistance (MAR index value of 0.56 which shown resistance to nine antibiotics. PCR analysis of virulence genes showed that all Salmonella isolates (100% were positive for the invA gene. Meanwhile, pefA was only identified in S. Enteritidis and S. Typhimurium. The findings in this study indicate that retail beef products tested were widely contaminated with multi-drug resistant (MDR Salmonella and various virulence genes are present among the isolated Salmonella serovars.

Lineage II (Serovar 1/2a and 1/2c) Human Listeria monocytogenes Pulsed-Field Gel Electrophoresis Types Divided into PFGE Groups Using the Band Patterns Below 145.5 kb.

Science.gov (United States)

Lopez-Valladares, Gloria; Danielsson-Tham, Marie-Louise; Goering, Richard V; Tham, Wilhelm

2017-01-01

Among 504 clinical lineage II isolates of Listeria monocytogenes isolated during 1958-2010 in Sweden, 119 pulsed-field gel electrophoresis (PFGE) types (AscI) have been identified based on the number and distribution of all banding patterns in each DNA profile. In this study, these types were further divided into PFGE groups based on the configuration of small bands with sizes kb. The 504 isolates included 483 serovar 1/2a isolates distributed into 114 PFGE types and 21 serovar 1/2c isolates distributed into 9 PFGE types; these were further divided into 21 PFGE groups. PFGE group, that is, configuration of small bands below 145.5 kb, and serovars were correlated. L. monocytogenes isolates belonging to PFGE groups A, B, C, E, F, H, K, L, M, S, V, W, Y, and Ö-6 to Ö-12 shared serovar 1/2a, with one exception. PFGE group E also included two PFGE types sharing serovar 1/2c and four PFGE types belonging to either serovar 1/2a or 1/2c. Isolates belonging to PFGE group N shared serovar 1/2c. In contrast to lineage I isolates, small fragments kb were visible in all L. monocytogenes isolates belonging to lineage II. In the results from both the present and previous studies, the genomic region of small bands was genetically more conservative than in large bands. The distribution of these small bands established the relatedness of strains and defined a genetic marker for both lineages I and II, while also establishing their serogroup. The division of L. monocytogenes PFGE types into PFGE groups is advantageous as the profile of every new isolate can be identified easily and quickly through first studying the PFGE group affiliation of the isolate based on the smaller band patterns kb, and then identifying the PFGE type based on the band patterns >145.5 kb.

AND Citrus senensis PEEL EXTRACTS ON Aeromonas hydrophila ...

African Journals Online (AJOL)

DR. AMINU

peel contains calcium, phosphorus, potassium, ascorbic acid, and vitamin A, as well as volatile oil and ..... A. comosus peel and C. senensis peel at 1:1 ratio against the isolates. Test organism. MIC value (mg/ml). MBC value (mg/ml). S. paratyphi B1. 0.25. 1.00. S. paratyphi B2. 0.25. 0.50. S. paratyphi B3. 0.25. -. S. paratyphi ...

Investigating the decay rates of Escherichia coli relative to Vibrio parahemolyticus and Salmonella Typhi in tropical coastal waters.

Science.gov (United States)

Lee, Choon Weng; Ng, Angie Yee Fang; Bong, Chui Wei; Narayanan, Kumaran; Sim, Edmund Ui Hang; Ng, Ching Ching

2011-02-01

Using the size fractionation method, we measured the decay rates of Escherichia coli, Salmonella Typhi and Vibrio parahaemolyticus in the coastal waters of Peninsular Malaysia. The size fractions were total or unfiltered, 0.7 μm) than in the smaller fraction (Vibrio grew well in seawater. There was usually an increase in Vibrio after one day incubation. Our results confirmed that decay or loss rates of E. coli did not match that of Vibrio, and also did not correlate with Salmonella decay rates. However E. coli showed persistence where its decay rates were generally lower than Salmonella. © 2010 Elsevier Ltd. All rights reserved.

Diagnosis of imported Ugandan typhoid fever based on local outbreak information: A case report.

Science.gov (United States)

Ota, Shinichiro; Maki, Yohei; Mori, Kazuma; Hamamoto, Takaaki; Kurokawa, Atsushi; Ishihara, Masashi; Yamamoto, Takayuki; Imai, Kazuo; Misawa, Kazuhisa; Yuki, Atsushi; Fujikura, Yuji; Maeda, Takuya; Kawana, Akihiko

2016-11-01

Re-emerging multidrug-resistant typhoid fever is becoming a worldwide threat, especially in East Africa. At the beginning of 2015, an outbreak of typhoid fever started in the capital city of Uganda, and 1940 suspected cases were reported by 5 March 2015. In this report, we describe a case of typhoid fever caused by a MDR strain with HIV infection and hemoglobin S-syndrome thalassemia in an Ugandan from Kampala City. It is essential to consider MDR strains of Salmonella enterica serovar Typhi infections, including fluoroquinolone-resistant strains, in patients from Africa and Southeast Asia. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

PATHOGENIC LEPTOSPIRA SEROVARS IN FREE-LIVING SEA LIONS IN THE GULF OF CALIFORNIA AND ALONG THE BAJA CALIFORNIA COAST OF MEXICO.

Science.gov (United States)

Avalos-Téllez, Rosalía; Carrillo-Casas, Erika M; Atilano-López, Daniel; Godínez-Reyes, Carlos R; Díaz-Aparicio, Efrén; Ramírez-Delgado, David; Ramírez-Echenique, María F; Leyva-Leyva, Margarita; Suzán, Gerardo; Suárez-Güemes, Francisco

2016-04-28

The California sea lion ( Zalophus californianus ), a permanent inhabitant of the Gulf of California in Mexico, is susceptible to pathogenic Leptospira spp. infection, which can result in hepatic and renal damage and may lead to renal failure and death. During summer 2013, we used the microscopic agglutination test (MAT) to investigate the prevalence of anti-Leptospira antibodies in blood of clinically healthy sea lion pups from seven rookery islands on the Pacific Coast of Baja California (Pacific Ocean) and in the Gulf of California. We also used PCR to examine blood for Leptospira DNA. Isolation of Leptospira in liquid media was unsuccessful. We found higher antibody prevalence in sea lions from the rookery islands in the gulf than in those from the Pacific Coast. Antibodies against 11 serovars were identified in the Gulf of California population; the most frequent reactions were against serovars Bataviae (90%), Pyrogenes (86%), Wolffi (86%), Celledoni (71%), and Pomona (65%). In the Pacific Ocean population, MAT was positive against eight serovars, where Wolffi (88%), Pomona (75%), and Bataviae (70%) were the most frequent. Serum samples agglutinated with more than one Leptospira serovar. The maximum titer was 3,200. Each island had a different serology profile, and islands combined showed a distinct profile for each region. We detected pathogenic Leptospira DNA in 63% of blood samples, but we found no saprophytic Leptospira. Positive PCR results were obtained in blood samples with high and low MAT titers. Together, these two methods enhance the diagnosis and interpretation of sea lion leptospirosis. Our results may be related to human activities or the presence of other reservoirs with which sea lions interact, and they may also be related to sea lion stranding.

Use of a recombinant Salmonella enterica serovar Typhimurium strain expressing C-Raf for protection against C-Raf induced lung adenoma in mice

International Nuclear Information System (INIS)

Gentschev, Ivaylo; Fensterle, Joachim; Schmidt, Andreas; Potapenko, Tamara; Troppmair, Jakob; Goebel, Werner; Rapp, Ulf R

2005-01-01

Serine-threonine kinases of the Raf family (A-Raf, B-Raf, C-Raf) are central players in cellular signal transduction, and thus often causally involved in the development of cancer when mutated or over-expressed. Therefore these proteins are potential targets for immunotherapy and a possible basis for vaccine development against tumors. In this study we analyzed the functionality of a new live C-Raf vaccine based on an attenuated Salmonella enterica serovar Typhimurium aroA strain in two Raf dependent lung tumor mouse models. The antigen C-Raf has been fused to the C-terminal secretion signal of Escherichia coli α-hemolysin and expressed in secreted form by an attenuated aroA Salmonella enterica serovar Typhimurium strain via the α-hemolysin secretion pathway. The effect of the immunization with this recombinant C-Raf strain on wild-type C57BL/6 or lung tumor bearing transgenic BxB mice was analyzed using western blot and FACS analysis as well as specific tumor growth assays. C-Raf antigen was successfully expressed in secreted form by an attenuated Salmonella enterica serovar Typhimurium aroA strain using the E. coli hemolysin secretion system. Immunization of wild-type C57BL/6 or tumor bearing mice provoked specific C-Raf antibody and T-cell responses. Most importantly, the vaccine strain significantly reduced tumor growth in two transgenic mouse models of Raf oncogene-induced lung adenomas. The combination of the C-Raf antigen, hemolysin secretion system and Salmonella enterica serovar Typhimurium could form the basis for a new generation of live bacterial vaccines for the treatment of Raf dependent human malignancies

Antibacterial activity of vegetal extracts against serovars of Salmonella Atividade antibacteriana de extratos vegetais sobre sorovares de Salmonella

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Daiane Voss-Rech

2011-02-01

Full Text Available in vitro antibacterial activity of 21 hydroethanolic vegetal extracts was assessed against 20 serovars of Salmonella. Regarding the tested extracts, 85.7% of them presented antibacterial activity. The six active extracts which showed activity on the largest number of serovars and the extract of Eucalyptus sp. were submitted to the determination of Minimum Inhibitory Concentration (MIC and Minimum Bactericidal Concentration (MBC. Of these, six extracts showed bacteriostatic and bactericidal activity with MIC and MBC for Punica granatum (pomegranate from 20 and 60mg mL-1, for Eugenia jambolana (rose apple from 40 and 240mg mL-1, Eugenia uniflora (surinam cherry from 80 and 240mg mL-1, Caryophyllus aromaticus (clove from 10 and 60mg mL-1, Psidium araca from 30 and 320mg mL-1 and Eucalyptus sp. from 40 and 160mg mL-1. Achyrocline satureioides (macela presented only bacteriostatic potential and MIC from 160mg mL-1. Caryophyllus aromaticus, Eucalyptus sp., and Psidium araca presented the best results for bactericidal activity, inhibiting, respectively, 84.2%, 42.1%, and 17.6% of Salmonella's serovars. The activity of each extract varied for different serovars; S. London presented resistance to the six extracts in MBC, while S. Pullorum was the most susceptible serovar.A atividade antibacteriana de 21 extratos hidroetanólicos vegetais foi avaliada in vitro frente a 20 sorovares de Salmonella. Dos extratos testados, 85,7% apresentaram atividade antibacteriana. Os seis extratos que evidenciaram atividade sobre o maior número de sorovares e Eucalyptus sp. foram submetidos à determinação da Concentração Inibitória Mínima (CIM e Concentração Bactericida Mínima (CBM. Destes, seis extratos apresentaram atividade bacteriostática e bactericida com MIC para Punica granatum (romã a partir de 20 e 60mg mL-1, Eugenia jambolana (jambolão de 40 e 240mg mL-1, Eugenia uniflora (pitanga de 80 e 240mg mL-1, Caryophyllus aromaticus (cravo de 10 e 60mg mL-1

Detection of Rickettsia felis, Rickettsia typhi, Bartonella Species and Yersinia pestis in Fleas (Siphonaptera) from Africa.

Science.gov (United States)

Leulmi, Hamza; Socolovschi, Cristina; Laudisoit, Anne; Houemenou, Gualbert; Davoust, Bernard; Bitam, Idir; Raoult, Didier; Parola, Philippe

2014-10-01

Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia pestis in domestic and urban flea populations in tropical and subtropical African countries. Fleas collected in Benin, the United Republic of Tanzania and the Democratic Republic of the Congo were investigated for the presence and identity of Rickettsia spp., Bartonella spp. and Yersinia pestis using two qPCR systems or qPCR and standard PCR. In Xenopsylla cheopis fleas collected from Cotonou (Benin), Rickettsia typhi was detected in 1% (2/199), and an uncultured Bartonella sp. was detected in 34.7% (69/199). In the Lushoto district (United Republic of Tanzania), R. typhi DNA was detected in 10% (2/20) of Xenopsylla brasiliensis, and Rickettsia felis was detected in 65% (13/20) of Ctenocephalides felis strongylus, 71.4% (5/7) of Ctenocephalides canis and 25% (5/20) of Ctenophthalmus calceatus calceatus. In the Democratic Republic of the Congo, R. felis was detected in 56.5% (13/23) of Ct. f. felis from Kinshasa, in 26.3% (10/38) of Ct. f. felis and 9% (1/11) of Leptopsylla aethiopica aethiopica from Ituri district and in 19.2% (5/26) of Ct. f. strongylus and 4.7% (1/21) of Echidnophaga gallinacea. Bartonella sp. was also detected in 36.3% (4/11) of L. a. aethiopica. Finally, in Ituri, Y. pestis DNA was detected in 3.8% (1/26) of Ct. f. strongylus and 10% (3/30) of Pulex irritans from the villages of Wanyale and Zaa. Most flea-borne infections are neglected diseases which should be monitored systematically in domestic rural and urban human populations to assess their epidemiological and clinical relevance. Finally, the presence of Y. pestis DNA in fleas captured in households was unexpected and raises a series of questions regarding the role of free fleas in the transmission of plague in rural Africa, especially in remote areas where the flea density in houses is high.

The transcriptional landscape and small RNAs of Salmonella enterica serovar Typhimurium

DEFF Research Database (Denmark)

Kröger, Carsten; Dillon, Shane C.; Cameron, Andrew D. S.

2012-01-01

More than 50 y of research have provided great insight into the physiology, metabolism, and molecular biology of Salmonella enterica serovar Typhimurium (S. Typhimurium), but important gaps in our knowledge remain. It is clear that a precise choreography of gene expression is required......-thirds of these TSSs were associated with σ70 (including phoP, slyA, and invF) from which we identified the −10 and −35 motifs of σ70-dependent S. Typhimurium gene promoters. Overall, we corrected the location of important genes and discovered 18 times more promoters than identified previously. S. Typhimurium...

25 years after Vi typhoid vaccine efficacy study, typhoid affects significant number of population in Nepal.

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Deepak Bajracharya

Full Text Available Salmonella Typhi, first isolated in 1884, results in infection of the intestines and can end in death and disability. Due to serious adverse events post vaccination, whole cell killed vaccines have been replaced with new generation vaccines. The efficacy of Vi polysaccharide (ViPS vaccine, a new generation, single-dose intramuscular typhoid vaccine was assessed in Nepal in 1987. However, despite the availability of ViPS vaccine for more than 25 years, Nepal has one of the highest incidence of typhoid fever. Therefore we collected information from hospitals in the Kathmandu Valley from over the past five years. There were 9901 enteric fever cases between January 2008 and July 2012. 1,881 of these were confirmed typhoid cases from five hospitals in the Kathmandu district. Approximately 70% of the cases involved children under 15 years old. 1281 cases were confirmed as S. Paratyphi. Vaccines should be prioritized for control of typhoid in conjunction with improved water and sanitation conditions in Nepal and in endemic countries of Asia and Africa.

Immunomagnetic nanoparticle based quantitative PCR for rapid detection of Salmonella

International Nuclear Information System (INIS)

Bakthavathsalam, Padmavathy; Rajendran, Vinoth Kumar; Saran, Uttara; Chatterjee, Suvro; Ali, Baquir Mohammed Jaffar

2013-01-01

We have developed a rapid and sensitive method for immunomagnetic separation (IMS) of Salmonella along with their real time detection via PCR. Silica-coated magnetic nanoparticles were functionalized with carboxy groups to which anti-Salmonella antibody raised against heat-inactivated whole cells of Salmonella were covalently attached. The immuno-captured target cells were detected in beverages like milk and lemon juice by multiplex PCR and real time PCR with a detection limit of 10 4 cfu.mL −1 and 10 3 cfu.mL −1 , respectively. We demonstrate that IMS can be used for selective concentration of target bacteria from beverages for subsequent use in PCR detection. PCR also enables differentiation of Salmonella typhi and Salmonella paratyphi A using a set of four specific primers. In addition, IMS—PCR can be used as a screening tool in the food and beverage industry for the detection of Salmonella within 3–4 h which compares favorably to the time of several days that is needed in case of conventional detection based on culture and biochemical methods. (author)

Antimicrobial mechanism of copper (II 1,10-phenanthroline and 2,2′-bipyridyl complex on bacterial and fungal pathogens

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S. Chandraleka

2014-12-01

Full Text Available Copper based metallo drugs were prepared and their antibacterial, antifungal, molecular mechanism of [Cu(SAlaPhen]·H2O and [Cu(SAlabpy]·H2O complexes were investigated. The [Cu(SAlaPhen]·H2O and [Cu(SAlabpy]·H2O were derived from the Schiff base alanine salicylaldehyde. [Cu(SAlaPhen]·H2O showed noteworthy antibacterial and antifungal activity than the [Cu(SAlabpy]·H2O and ligand alanine, salicylaldehyde. The [Cu(SAlaPhen]·H2O complex showed significant antibacterial activity against Salmonella typhi, Staphylococcus aureus, Salmonella paratyphi and the antifungal activity against Candida albicans and Cryptococcus neoformans in well diffusion assay. The mode of action of copper (II complex was analyzed by DNA cleavage activity and in silico molecular docking. The present findings provide important insight into the molecular mechanism of copper (II complexes in susceptible bacterial and fungal pathogens. These results collectively support the use of [Cu(SAlaPhen]·H2O complex as a suitable drug to treat bacterial and fungal infections.

Analysis of the clonal relationship among clinical isolates of Salmonella enterica serovar Infantis by different typing methods Análisis de la relación clonal entre aislamientos clínicos de Salmonella enterica serovar Infantis mediante diferentes métodos de tipificación

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Luis A. Merino

2003-06-01

Full Text Available Salmonella Infantis has been the second most common serovar in Argentina in the last two years, being isolated mostly from paediatric hospitalised patients. In order to determine the clonal relationship among Salmonella Infantis strains, we examined 15 isolates from paediatric patient faeces in Argentina (12 geographically related and 3 geographically non-related by using antimicrobial susceptibility, plasmid profiling, repetitive extragenic palindromic (REP PCR, enterobacterial repetitive intergenic consensus (ERIC PCR, and low-frequency restriction analysis of chromosomal DNA by pulsed field gel electrophoresis (PFGE. Four Spanish strains were included as controls of clonal diversity in molecular techniques. Antibiotype and plasmid profile was not useful as epidemiological tools. PFGE and REP-PCR were able to discriminate between Argentinean and Spanish isolates of Salmonella Infantis allowing to detect genetically related strains in three different cities. This finding indicates that a possible spread of a clone of this serovar in the North-eastern Region of Argentina has taken place in 1998.Salmonella Infantis ha sido el segundo serovar más común en la Argentina en los últimos dos años, siendo aislada principalmente, a partir de pacientes pediátricos hospitalizados. La relación clonal entre 15 aislamientos de Salmonella Infantis obtenidos de heces de pacientes pediátricos en Argentina se estudió mediante la susceptibilidad antimicrobiana, el perfil plasmídico, amplificación por reacción en cadena de la polimerasa (PCR de las secuencias repetitivas REP y ERIC, y electroforesis de ADN total en campo pulsátil (PFGE. Cuatro cepas españolas fueron incluidas como control de diversidad clonal. El antibiotipo y el perfil plasmídico no fueron herramientas útiles en la tipificación. PFGE y REP-PCR fueron capaces de discriminar entre las cepas argentinas y españolas de Salmonella Infantis, permitiendo detectar cepas gen

MARTX Toxin in the Zoonotic Serovar of Vibrio vulnificus Triggers an Early Cytokine Storm in Mice

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Celia Murciano

2017-07-01

Full Text Available Vibrio vulnificus biotype 2-serovar E is a zoonotic clonal complex that can cause death by sepsis in humans and fish. Unlike other biotypes, Bt2 produces a unique type of MARTXVv (Multifunctional-Autoprocessive-Repeats-in-Toxin; RtxA13, which is encoded by a gene duplicated in the pVvBt2 plasmid and chromosome II. In this work, we analyzed the activity of this toxin and its role in human sepsis by performing in vitro, ex vivo, and in vivo assays. First, we demonstrated that the ACD domain, present exclusively in this toxin variant, effectively has an actin-cross-linking activity. Second, we determined that the whole toxin caused death of human endotheliocytes and monocytes by lysis and apoptosis, respectively. Finally, we tested the hypothesis that RtxA13 contributes to human death caused by this zoonotic serovar by triggering an early cytokine storm in blood. To this end, we used a Bt2-SerE strain (R99 together with its rtxA13 deficient mutant, and a Bt1 strain (YJ016 producing RtxA11 (the most studied MARTXVv together with its rtxA11 deficient mutant, as controls. Our results showed that RtxA13 was essential for virulence, as R99ΔΔrtxA13 was completely avirulent in our murine model of infection, and that R99, but not strain YJ016, induced an early, strong and dysregulated immune response involving the up-regulation of a high number of genes. This dysregulated immune response was directly linked to RtxA13. Based on these results and those obtained ex vivo (human blood, we propose a model of infection for the zoonotic serovar of V. vulnificus, in which RtxA13 would act as a sepsis-inducing toxin.

Characterization and identification of early proteins in Chlamydia trachomatis serovar L2 by two-dimensional gel electrophoresis

DEFF Research Database (Denmark)

Lundemose, AG; Birkelund, Svend; Larsen, PM

1990-01-01

The synthesis of early proteins from Chlamydia trachomatis serovar L2 was analyzed by two-dimensional gel electrophoresis. By pulse-label experiments, the synthesis of seven proteins was observed at 2 to 8 h postinfection before the major outer membrane protein was detected at 8 to 10 h after...

Epidemiological investigation of an outbreak of typhoid fever in Jorhat town of Assam, India.

Science.gov (United States)

Roy, Jashbeer Singh; Saikia, Lahari; Medhi, Mithu; Tassa, Dipak

2016-10-01

Typhoid fever is a global health problem and is also endemic in India. An outbreak of fever occurred in January 2014 in Jorhat Town in Assam, India. Here we report the results of an investigation done to find out the aetiology and source of the outbreak. The affected areas were visited on January 23, 2014 by a team of Jorhat district Integrated Disease Surveillance Project personnel. A total of 13 blood samples from patients with fever as first symptom and six water samples were collected from the affected areas. The blood samples were cultured and isolates were identified using standard biochemical tests. Isolates were also tested for antimicrobial sensitivity. Widal test was performed on 10 of the 13 blood samples collected. Sanitary survey was carried out to find any leakage in the water supply and also the sewage system of the Jorhat town. Blood culture yielded Salmonella enterica serovar Typhi in six (46.15%) patients whereas Widal test was positive in 10 (76.9%) of 13 patients. Water culture showed presumptive coliform count of >180/100 ml in two out of the six samples tested. Salmonella Typhi was also isolated from water culture of these two samples. Sanitary survey carried out in the affected places showed that the water supply pipes of urban water supply were in close proximity to the sewage drainage system and there were few leakages. The outbreak occurred due to S. Typhi contaminating the water supply. Sanitation and immunization are the two most important components to be stressed to prevent such outbreaks.

Three case studies involving Leptospira interrogans serovar pomona infection in mixed farming units : case report

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B. Gummow

1999-07-01

Full Text Available Three case studies involving Leptospira interrogans serovar pomona outbreaks within mixed farming systems in South Africa are described. On 2 farms, pigs constituted the main enterprise with cattle and sheep of secondary importance. On each of these 2 farms, abortion due to L. pomona in sows was confirmed by culture, and antibody titres to pomona were detected in cattle, sheep, horses and dogs. On the 3rd farm, a piggery was ofsecondary importance to cattle farming. Abortion and death in cows occurred on this farmand serology showed titres to various serovars, including pomona. L. pomona was also isolated from bovine urine, an aborted bovine foetus and kidneys from slaughtered pigs. This particular case study was regarded as clinically atypical in that adult Jersey cattle died of acute leptospirosis in a semiarid region of South Africa. In all 3 case studies, the poor management of pig effluent and of the drinking water and its sources played a pivotal role in the transmission of the disease. Inadequate vaccination of animals against Leptospira and poor record-keeping within the secondary farming enterprises were also contributing factors to the spread of leptospirosis.

An Outbreak of Food-Borne Typhoid Fever Due to Salmonella enterica Serotype Typhi in Japan Reported for the First Time in 16 Years

Science.gov (United States)

Kobayashi, Tetsuro; Kutsuna, Satoshi; Hayakawa, Kayoko; Kato, Yasuyuki; Ohmagari, Norio; Uryu, Hideko; Yamada, Ritsuko; Kashiwa, Naoyuki; Nei, Takahito; Ehara, Akihito; Takei, Reiko; Mori, Nobuaki; Yamada, Yasuhiro; Hayasaka, Tomomi; Kagawa, Narito; Sugawara, Momoko; Suzaki, Ai; Takahashi, Yuno; Nishiyama, Hiroyuki; Morita, Masatomo; Izumiya, Hidemasa; Ohnishi, Makoto

2016-01-01

For the first time in 16 years, a food-borne outbreak of typhoid fever due to Salmonella enterica serotype Typhi was reported in Japan. Seven patients consumed food in an Indian buffet at a restaurant in the center of Tokyo, while one was a Nepali chef in the restaurant, an asymptomatic carrier and the implicated source of this outbreak. The multiple-locus variable-number tandem repeat analysis showed 100% consistency in the genomic sequence for five of the eight cases. PMID:26621565

Recurrent paratyphoid fever A co-infected with hepatitis A reactivated chronic hepatitis B.

Science.gov (United States)

Liu, Yanling; Xiong, Yujiao; Huang, Wenxiang; Jia, Bei

2014-05-12

We report here a case of recurrent paratyphoid fever A with hepatitis A co-infection in a patient with chronic hepatitis B. A 26-year-old male patient, who was a hepatitis B virus carrier, was co-infected with Salmonella enterica serovar Paratyphi A and hepatitis A virus. The recurrence of the paratyphoid fever may be ascribed to the coexistence of hepatitis B, a course of ceftriaxone plus levofloxacin that was too short and the insensitivity of paratyphoid fever A to levofloxacin. We find that an adequate course and dose of ceftriaxone is a better strategy for treating paratyphoid fever. Furthermore, the co-infection of paratyphoid fever with hepatitis A may stimulate cellular immunity and break immunotolerance. Thus, the administration of the anti-viral agent entecavir may greatly improve the prognosis of this patient with chronic hepatitis B, and the episodes of paratyphoid fever and hepatitis A infection prompt the use of timely antiviral therapy.

A rapid and specific detection of pathogenic serovar Salmonella typhimurium by loop-mediated isothermal amplification method (LAMP

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Hadi Ravan

2017-09-01

Discussion and conclusion: As a result of a high sensitivity and specificity of the method as well as its low cost per assay, it could be concluded that the present LAMP assay is a powerful, accurate, and efficient method for detecting pathogenic serovar Salmonella typhimurium in food-processing industries and diagnostic laboratories.

Ascertaining the relationship between Salmonella Typhimurium and Salmonella 4,[5],12:i:- by MLVA and inferring the sources of human salmonellosis due to the two serovars in Italy

DEFF Research Database (Denmark)

Barco, Lisa; Barrucci, Federica; Cortini, Enzo

2015-01-01

The current picture of human salmonellosis shows Salmonella Typhimurium and S. 4,[5],12:i:- as the most common serovars in Italy. The aims of this study were to investigate the genetic relationship between these serovars, as well as to test the possibility of inferring sources of human...... salmonellosis due to S. Typhimurium and S. 4,[5],12:i:- by using multilocus variable-number tandem repeat analysis (MLVA) subtyping data. Single isolates from 268 human sporadic cases and 325 veterinary isolates (from pig, cattle, chicken, and turkey) collected over the period 2009-2011 were typed by MLVA......, and the similarities of MLVA profiles were investigated using different analytical approaches. Results showed that isolates of S. 4,[5],12:i:- were more clonal compared to S. Typhimurium and that clones of both serovars from different non-human sources were very close to those which were responsible for human...

Effect of Challenge Temperature and Solute Type on Heat Tolerance of Salmonella Serovars at Low Water Activity

Science.gov (United States)

Mattick, K. L.; Jørgensen, F.; Wang, P.; Pound, J.; Vandeven, M. H.; Ward, L. R.; Legan, J. D.; Lappin-Scott, H. M.; Humphrey, T. J.

2001-01-01

Salmonella spp. are reported to have an increased heat tolerance at low water activity (aw; measured by relative vapor pressure [rvp]), achieved either by drying or by incorporating solutes. Much of the published data, however, cover only a narrow treatment range and have been analyzed by assuming first-order death kinetics. In this study, the death of Salmonella enterica serovar Typhimurium DT104 when exposed to 54 combinations of temperature (55 to 80°C) and aw (rvp 0.65 to 0.90, reduced using glucose-fructose) was investigated. The Weibull model (LogS = −btn) was used to describe microbial inactivation, and surface response models were developed to predict death rates for serovar Typhimurium at all points within the design surface. The models were evaluated with data generated by using six different Salmonella strains in place of serovar Typhimurium DT104 strain 30, two different solutes in place of glucose-fructose to reduce aw, or six low-aw foods artificially contaminated with Salmonella in place of the sugar broths. The data demonstrate that, at temperatures of ≥70°C, Salmonella cells at low aw were more heat tolerant than those at a higher aw but below 65°C the reverse was true. The same patterns were generated when sucrose (rvp 0.80 compared with 0.90) or NaCl (0.75 compared with 0.90) was used to reduce aw, but the extent of the protection afforded varied with solute type. The predictions of thermal death rates in the low-aw foods were usually fail-safe, but the few exceptions highlight the importance of validating models with specific foods that may have additional factors affecting survival. PMID:11526015

Serological and molecular characterization of leptospira serovar Kenya from captive African giant pouched rats (Cricetomys gambianus) from Morogoro Tanzania

NARCIS (Netherlands)

Machang'u, R. S.; Mgode, G. F.; Assenga, J.; Mhamphi, G.; Weetjens, B.; Cox, C.; Verhagen, R.; Sondij, S.; Goris, M. G.; Hartskeerl, R. A.

2004-01-01

Two identical leptospiral isolates coded Sh9 and Sh25 obtained from the urine of captive African giant pouched rats (Cricetomys gambianus), destined for use as biodetector of antipersonnel landmines were typed as serovar Kenya using cross-agglutination absorption test and DNA fingerprinting with the

Quantification of contamination of lettuce by GFP-expressing Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium

NARCIS (Netherlands)

Franz, Eelco; Visser, Anna A; Van Diepeningen, Anne D; Klerks, Michel M; Termorshuizen, Aad J; van Bruggen, Ariena H C

The primary objective of this study was to determine the possibility of internalization of GFP-expressing Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium (S. Typhimurium) strains MAE 110 (multi-cellular morphology) and 119 (wild type morphology) into lettuce seedlings (Lactuca

Influence of ethanol adaptation on Salmonella enterica serovar Enteritidis survival in acidic environments and expression of acid tolerance-related genes

Science.gov (United States)

Aims: Salmonella enterica serovar Enteritidis (S. Enteritidis) can encounter mild ethanol stress during its life cycle. However, adaptation to a stressful condition may affect bacterial resistance to subsequent stresses. Hence, this work was undertaken to investigate the influences of ethanol adapta...

Characterization of antimicrobial resistance in Salmonella enterica food and animal isolates from Colombia: identification of a qnrB19-mediated quinolone resistance marker in two novel serovars

DEFF Research Database (Denmark)

Karczmarczyk, M.; Martins, M.; McCusker, M.

2010-01-01

Ninety-three Salmonella isolates recovered from commercial foods and exotic animals in Colombia were studied. The serotypes, resistance profiles and where applicable the quinolone resistance genes were determined. Salmonella Anatum (n=14), Uganda (19), Braenderup (10) and Newport (10) were the most...... plasmids, two of which were completely sequenced. These exhibited 97% (serovar 6,7:d:- isolate) and 100% (serovar Infantis isolate) nucleotide sequence identity with previously identified ColE-like plasmids. This study demonstrates the occurrence of the qnrB19 gene associated with small ColE plasmids...

Prevalence of Salmonella Excretion in Stool: A Community Survey in 2 Sites, Guinea-Bissau and Senegal.

Science.gov (United States)

Im, Justin; Nichols, Chelsea; Bjerregaard-Andersen, Morten; Sow, Amy Gassama; Løfberg, Sandra; Tall, Adama; Pak, Gi Deok; Aaby, Peter; Baker, Stephen; Clemens, John D; Espinoza, Ligia Maria Cruz; Konings, Frank; May, Jürgen; Monteiro, Mario; Niang, Aissatou; Panzner, Ursula; Park, Se Eun; Schütt-Gerowitt, Heidi; Wierzba, Thomas F; Marks, Florian; von Kalckreuth, Vera

2016-03-15

Chronic and convalescent carriers play an important role in the transmission and endemicity of many communicable diseases. A high incidence of Salmonella enterica serovar Typhi and invasive nontyphoidal Salmonella (NTS) infection has been reported in parts of sub-Saharan Africa, yet the prevalence of Salmonella excretion in the general population is unknown. Stool specimens were collected from a random sample of households in 2 populations in West Africa: Bissau, Guinea-Bissau, and Dakar, Senegal. Stool was cultured to detect presence of Salmonella, and antimicrobial susceptibility testing was performed on the isolated organisms. Stool was cultured from 1077 and 1359 individuals from Guinea-Bissau and Senegal, respectively. Salmonella Typhi was not isolated from stool samples at either site. Prevalence of NTS in stool samples was 24.1 (95% confidence interval [CI], 16.5-35.1; n = 26/1077) per 1000 population in Guinea-Bissau and 10.3 (95% CI, 6.1-17.2; n = 14/1359) per 1000 population in Senegal. Evidence of NTS excretion in stool in both study populations indicates a possible NTS transmission route in these settings. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Characterization of a multidrug-resistant Salmonella enterica serovar Heidelberg outbreak strain in commercial turkeys: Colonization, transmission, and host transcriptional response

Science.gov (United States)

In recent years, multidrug-resistant (MDR) Salmonella enterica serovar Heidelberg has been associated with numerous human foodborne illness outbreaks due to consumption of poultry. For example, in 2011, an MDR S. Heidelberg outbreak associated with ground turkey sickened 136 individuals and resulted...

rpoS-Regulated core genes involved in the competitive fitness of Salmonella enterica Serovar Kentucky in the intestines of chickens.

Science.gov (United States)

Cheng, Ying; Pedroso, Adriana Ayres; Porwollik, Steffen; McClelland, Michael; Lee, Margie D; Kwan, Tiffany; Zamperini, Katherine; Soni, Vivek; Sellers, Holly S; Russell, Scott M; Maurer, John J

2015-01-01

Salmonella enterica serovar Kentucky has become the most frequently isolated serovar from poultry in the United States over the past decade. Despite its prevalence in poultry, it causes few human illnesses in the United States. The dominance of S. Kentucky in poultry does not appear to be due to single introduction of a clonal strain, and its reduced virulence appears to correlate with the absence of virulence genes grvA, sseI, sopE, and sodC1. S. Kentucky's prevalence in poultry is possibly attributable to its metabolic adaptation to the chicken cecum. While there were no difference in the growth rate of S. Kentucky and S. Typhimurium grown microaerophilically in cecal contents, S. Kentucky persisted longer when chickens were coinfected with S. Typhimurium. The in vivo advantage that S. Kentucky has over S. Typhimurium appears to be due to differential regulation of core Salmonella genes via the stationary-phase sigma factor rpoS. Microarray analysis of Salmonella grown in cecal contents in vitro identified several metabolic genes and motility and adherence genes that are differentially activated in S. Kentucky. The contributions of four of these operons (mgl, prp, nar, and csg) to Salmonella colonization in chickens were assessed. Deletion of mgl and csg reduced S. Kentucky persistence in competition studies in chickens infected with wild-type or mutant strains. Subtle mutations affecting differential regulation of core Salmonella genes appear to be important in Salmonella's adaptation to its animal host and especially for S. Kentucky's emergence as the dominant serovar in poultry. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Neutral genomic microevolution of a recently emerged pathogen, Salmonella enterica serovar Agona.

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Zhemin Zhou

2013-04-01

Full Text Available Salmonella enterica serovar Agona has caused multiple food-borne outbreaks of gastroenteritis since it was first isolated in 1952. We analyzed the genomes of 73 isolates from global sources, comparing five distinct outbreaks with sporadic infections as well as food contamination and the environment. Agona consists of three lineages with minimal mutational diversity: only 846 single nucleotide polymorphisms (SNPs have accumulated in the non-repetitive, core genome since Agona evolved in 1932 and subsequently underwent a major population expansion in the 1960s. Homologous recombination with other serovars of S. enterica imported 42 recombinational tracts (360 kb in 5/143 nodes within the genealogy, which resulted in 3,164 additional SNPs. In contrast to this paucity of genetic diversity, Agona is highly diverse according to pulsed-field gel electrophoresis (PFGE, which is used to assign isolates to outbreaks. PFGE diversity reflects a highly dynamic accessory genome associated with the gain or loss (indels of 51 bacteriophages, 10 plasmids, and 6 integrative conjugational elements (ICE/IMEs, but did not correlate uniquely with outbreaks. Unlike the core genome, indels occurred repeatedly in independent nodes (homoplasies, resulting in inaccurate PFGE genealogies. The accessory genome contained only few cargo genes relevant to infection, other than antibiotic resistance. Thus, most of the genetic diversity within this recently emerged pathogen reflects changes in the accessory genome, or is due to recombination, but these changes seemed to reflect neutral processes rather than Darwinian selection. Each outbreak was caused by an independent clade, without universal, outbreak-associated genomic features, and none of the variable genes in the pan-genome seemed to be associated with an ability to cause outbreaks.

Expression of Bacillus thuringiensis serovar. israelensis toxins in Asticcacaulis excentricus to control dipteran larvae of vectors of diseases

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Óscar Enrique Guevara

2004-01-01

Full Text Available Bacillus thuringiensis cry genes encode for a diverse group of crystal-forming proteins that exhibit insecticidal activity towards dipteran, lepidopteran and coleopteran larvae. The effectiveness of insecticides based on mosquito larvicidal B. thuringiensis strains can be enhanced by using aquatic prosthecated bacteria as alternative hosts, since they do not sink, cytoplasmic located toxins are protected f rom UV radiation and, most importantly, mosquito larvae feed on them. An Asticcacaulis excentricus reference strain was transformed with the cry1 1Aa gene from Bacillus thuringiensis serovar. israelensis. Western blot and electrophoresis were used to test recombinant protein expression; Western blot revealed a 72 kDa protein corresponding to B. thuringiensis serovar. israelensis Cry1 1 Aa. These aquatic bacte­rias toxicity achieved 50% mortality at 23 ng/mL concentration in f irst instar Culex quinquefasciatus larvae. Other bioassays indicated that recombinant A. excentricus is toxic against Aedes aegyptiand Anopheles albimanus first instar larvae. Buoyancy tests demonstrated the advantage of A. excentricus over B. thuringiensis. Key words: Asticcacaulis excentricus, Bacillus thuringiensis, prosthecated bacteria, dengue, malaria.

Chlamydia trachomatis serovar distribution and other sexually transmitted coinfections in subjects attending an STD outpatients clinic in Italy.

Science.gov (United States)

Marangoni, Antonella; Foschi, Claudio; Nardini, Paola; D'Antuono, Antonietta; Banzola, Nicoletta; Di Francesco, Antonietta; Ostanello, Fabio; Russo, Incoronata; Donati, Manuela; Cevenini, Roberto

2012-04-01

We studied the prevalence of Chlamydia trachomatis (CT) urogenital infection and the distribution of different genotypes in a non-selected STD population of 1625 patients, evaluating presence of coinfections with other sexually transmitted diseases. Each patient was bled to perform serological tests for syphilis and HIV, then urethral or endocervical swabs were obtained for the detection of CT and Neisseria gonorrhoeae by culture. DNA extracted from remnant positive swabs was amplified by omp1 Nested PCR and products were sequenced. Total prevalence of CT infection was 6.3% (103/1625), with strong differences between men and women (11.4% vs 3.9%, Pmen than in women (Pmen and women (P=0.042) and among patients with or without coinfection (P=0.035); patients infected by serovar D/Da showed the highest coinfection rate. This study can be considered a contribution in increasing knowledge on CT serovar distribution in Italy. Further studies are needed to better define molecular epidemiology of CT infection and to investigate its correlation with other STDs.

High resolution clustering of Salmonella enterica serovar Montevideo strains using a next-generation sequencing approach

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Allard Marc W

2012-01-01

Full Text Available Abstract Background Next-Generation Sequencing (NGS is increasingly being used as a molecular epidemiologic tool for discerning ancestry and traceback of the most complicated, difficult to resolve bacterial pathogens. Making a linkage between possible food sources and clinical isolates requires distinguishing the suspected pathogen from an environmental background and placing the variation observed into the wider context of variation occurring within a serovar and among other closely related foodborne pathogens. Equally important is the need to validate these high resolution molecular tools for use in molecular epidemiologic traceback. Such efforts include the examination of strain cluster stability as well as the cumulative genetic effects of sub-culturing on these clusters. Numerous isolates of S. Montevideo were shot-gun sequenced including diverse lineage representatives as well as numerous replicate clones to determine how much variability is due to bias, sequencing error, and or the culturing of isolates. All new draft genomes were compared to 34 S. Montevideo isolates previously published during an NGS-based molecular epidemiological case study. Results Intraserovar lineages of S. Montevideo differ by thousands of SNPs, that are only slightly less than the number of SNPs observed between S. Montevideo and other distinct serovars. Much less variability was discovered within an individual S. Montevideo clade implicated in a recent foodborne outbreak as well as among individual NGS replicates. These findings were similar to previous reports documenting homopolymeric and deletion error rates with the Roche 454 GS Titanium technology. In no case, however, did variability associated with sequencing methods or sample preparations create inconsistencies with our current phylogenetic results or the subsequent molecular epidemiological evidence gleaned from these data. Conclusions Implementation of a validated pipeline for NGS data acquisition and

Genomic analysis of $\\textit{Salmonella enterica}$ serovar Typhimurium from wild passerines in England and Wales

OpenAIRE

Mather, Alison E; Lawson, Becki; de, Pinna Elizabeth; Wigley, Paul; Parkhill, Julian; Thomson, Nicholas R; Page, Andrew J; Holmes, Mark Adrian; Paterson, Gavin K

2016-01-01

Passerine salmonellosis is a well-recognised disease of birds in the order Passeriformes, including common songbirds such as finches and sparrows, caused by infection with $\\textit{Salmonella enterica}$ serovar Typhimurium. Previous research has suggested that some subtypes of S. Typhimurium – definitive phage types (DT) 40, 56 variant, and 160 – are host-adapted to passerines, and that these birds may represent a reservoir of infection for humans and other animals. Here, we have used whole g...

Prevalence of antimicrobial resistance of non-typhoidal Salmonella serovars in retail aquaculture products.

Science.gov (United States)

Zhang, Jianmin; Yang, Xiaowei; Kuang, Dai; Shi, Xianming; Xiao, Wenjia; Zhang, Jing; Gu, Zhen; Xu, Xuebin; Meng, Jianghong

2015-10-01

Aquaculture products can become sources of Salmonella by exposure to contaminated water or through processing practices, thus representing a public health hazard. A study was conducted on Salmonella contamination in aquaculture products sampled from marketplaces and retailers in Shanghai, China. A total of 730 samples (including fish, shellfish, bullfrog, clam, shrimp and others) were obtained from 2006 to 2011. Among them, 217 (29.7%) were positive for Salmonella. Thirty-eight serovars were identified in the 217 Salmonella isolates. The most prevalent were Salmonella Aberdeen (18.4%), S. Wandsworth (12.0%), S. Thompson (9.2%), S. Singapore (5.5%), S. Stanley (4.6%), S. Schwarzengrund (4.6%), S. Hvittingfoss (4.1%) and S. Typhimurium (4.1%). Many resistant isolates were detected, with 69.6% resistant to at least one antimicrobial drug. We observed high resistance to sulfonamides (56.5%), tetracycline (34.1%), streptomycin (28.6%), ampicillin (23.5%) and nalidixic acid (21.2%). Lower levels of resistance were found for gentamicin (3.2%), ciprofloxacin (2.3%), ceftiofur (1.3%), cefotaxime (0.9%), ceftazidime (0.5%) and cefepime (0.5%). A total of 43.3% of the Salmonella isolates were multidrug-resistant and 44 different resistance patterns were found. This study provided data on the prevalence, serovars and antimicrobial resistance of Salmonella from retail aquaculture products in Shanghai, and indicated the need for monitoring programs for microbiologic safety in such projects and for more prudent drug use in aquaculture production in order to reduce the risk of development and spread of antimicrobial resistance. Copyright © 2015 Elsevier B.V. All rights reserved.

Antibacterial activity of crude extracts of some South African medicinal plants against multidrug resistant etiological agents of diarrhoea.

Science.gov (United States)

Bisi-Johnson, Mary A; Obi, Chikwelu L; Samuel, Babatunde B; Eloff, Jacobus N; Okoh, Anthony I

2017-06-19

This study evaluated the antibacterial activity of some plants used in folklore medicine to treat diarrhoea in the Eastern Cape Province, South Africa. The acetone extracts of Acacia mearnsii De Wild., Aloe arborescens Mill., A. striata Haw., Cyathula uncinulata (Schrad.) Schinz, Eucomis autumnalis (Mill.) Chitt., E. comosa (Houtt.) Wehrh., Hermbstaedtia odorata (Burch. ex Moq.) T.Cooke, Hydnora africana Thunb, Hypoxis latifolia Wight, Pelargonium sidoides DC, Psidium guajava L and Schizocarphus nervosus (Burch.) van der Merwe were screened against Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, multi-resistant Salmonella enterica serovar Isangi, S. typhi, S. enterica serovar Typhimurium, Shigella flexneri type 1b and Sh. sonnei phase II. A qualitative phytochemical screening of the plants extracts was by thin layer chromatography. Plants extracts were screened for antibacterial activity using serial dilution microplate technique and bioautography. The TLC fingerprint indicated the presence of terpenoids and flavonoids in the herbs. Most of the tested organisms were sensitive to the crude acetone extracts with minimum inhibitory concentration (MIC) values ranging from 0.018-2.5 mg/mℓ. Extracts of A. striata, C. uncinulata, E. autumnalis and P. guajava were more active against enteropathogens. S. aureus and Sh. flexneri were the most sensitive isolates to the crude extracts but of significance is the antibacterial activity of A. arborescens and P. guajava against a confirmed extended spectrum betalactamase positive S. enterica serovar Typhimurium. The presence of bioactive compounds and the antibacterial activity of some of the selected herbs against multidrug resistant enteric agents corroborate assertions by traditional healers on their efficacies.

Defining the Core Genome of Salmonella enterica Serovar Typhimurium for Genomic Surveillance and Epidemiological Typing

Science.gov (United States)

Fu, Songzhe; Octavia, Sophie; Tanaka, Mark M.; Sintchenko, Vitali

2015-01-01

Salmonella enterica serovar Typhimurium is the most common Salmonella serovar causing foodborne infections in Australia and many other countries. Twenty-one S. Typhimurium strains from Salmonella reference collection A (SARA) were analyzed using Illumina high-throughput genome sequencing. Single nucleotide polymorphisms (SNPs) in 21 SARA strains ranged from 46 to 11,916 SNPs, with an average of 1,577 SNPs per strain. Together with 47 strains selected from publicly available S. Typhimurium genomes, the S. Typhimurium core genes (STCG) were determined. The STCG consist of 3,846 genes, a set that is much larger than that of the 2,882 Salmonella core genes (SCG) found previously. The STCG together with 1,576 core intergenic regions (IGRs) were defined as the S. Typhimurium core genome. Using 93 S. Typhimurium genomes from 13 epidemiologically confirmed community outbreaks, we demonstrated that typing based on the S. Typhimurium core genome (STCG plus core IGRs) provides superior resolution and higher discriminatory power than that based on SCG for outbreak investigation and molecular epidemiology of S. Typhimurium. STCG and STCG plus core IGR typing achieved 100% separation of all outbreaks compared to that of SCG typing, which failed to separate isolates from two outbreaks from background isolates. Defining the S. Typhimurium core genome allows standardization of genes/regions to be used for high-resolution epidemiological typing and genomic surveillance of S. Typhimurium. PMID:26019201

IDENTIFICATION OF SALMONELLA SEROVARS ISOLATED DURING 2009-2016 IN TERNOPIL REGION, UKRAINE

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Pokryshko O.V.

2017-06-01

Full Text Available Introduction. Salmonellosis is registered in all regions of the world. Relevance of salmonellosis is due its global distribution, increasing incidence, even in developed countries, frequent outbreaks. The most reports in different countries demonstrated that one of the common Salmonella serotypes isolated from food and environmental samples had been serovars Salmonella Enterica, Typhimurium. In Ukraine 7.3% of all acute diarrheal infections have been cases of salmonellosis. Although large Salmonella outbreaks usually attract media attention, 60–80% of all salmonellosis cases are not recognized as part of a known outbreak and are classified as sporadic cases, or are not diagnosed as such at all. Material & methods. The samples from cultured stool, bile samples, food and environment were inoculated in the Tryptic Soya Broth (TSB for the enrichment and detection of the bacteria. After 24 hours incubation, microorganisms were cultured on the MacConkey agar plates. Then biochemical and serological tests were performed to identify the serovars of the isolated Salmonella in Ternopil regional laboratory center, Ukraine.Results & discussion. Over the past 8 years the incidence of salmonellosis has varied between 8.41 3.3 cases per 100 thousand of population (35 - 90 cases. During this period, the lowest rate recorded in 2015 (3.3 cases per 100 thousand of population, the highest – in 2014. Analysis of morbidity has been shown that elevated levels of infection were due to outbreaks registrated in 2011 (the number of infected people was 23, in 2013 (53 infected people, in 2014 (67 infected people and in 2016 (16 infected people. In Ternopil region the dominant serovar of Salmonella spp. isolated from patients are S. enteritidis (56.8 - 93.5% of all cases of diseases and S. typhimurium (7.8 - 43.8% in last 8 years. Among the carriers circulate S.enteritidis, S. typhimurium – mainly (64,8% and 35.2% respectively. Not typical for Ternopil region

Demonstration of persistent contamination of a cooked egg product production facility with Salmonella enterica serovar Tennessee and characterization of the persistent strain.

Science.gov (United States)

Jakočiūnė, D; Bisgaard, M; Pedersen, K; Olsen, J E

2014-08-01

The aim of this study was to investigate whether continuous contamination of light pasteurized egg products with Salmonella enterica serovar Tennessee (S. Tennessee) at a large European producer of industrial egg products was caused by persistent contamination of the production facility and to characterize the persistent strains. Seventy-three S. Tennessee isolates collected from products over a 3-year period with intermittent contamination, and 15 control strains were compared by pulsed field gel electrophoresis (PFGE) using two enzymes. Forty-five case isolates distributed throughout the full period were shown to belong to one profile type. Isolates representing different PFGE profiles were all assigned to ST 319 by multilocus sequence typing (MLST). The case isolates did not show a higher ability to form biofilm on a plastic surface than noncase isolates. Characteristically, members of the persistent clone were weak producers of H2 S in laboratory medium. S. Tennessee isolated from the case was able to grow better in pasteurized egg product compared with other serovars investigated. It was concluded that the contamination was caused by a persistent strain in the production facility and that this strain apparently had adapted to grow in the relevant egg product. S. Tennessee has previously been associated with persistence in hatching facilities. This is the first report of persistent contamination of an egg production facility with this serovar. © 2014 The Society for Applied Microbiology.

Prevalence, serovars, phage types, and antibiotic susceptibilities of Salmonella strains isolated from animals in the United Arab Emirates from 1996 to 2009.

Science.gov (United States)

Münch, Sebastian; Braun, Peggy; Wernery, Ulrich; Kinne, Jörg; Pees, Michael; Flieger, Antje; Tietze, Erhard; Rabsch, Wolfgang

2012-10-01

The aim of this study was to give some insights into the prevalence, serovars, phage types, and antibiotic resistances of Salmonella from animal origin in the United Arab Emirates. Data on diagnostic samples from animals (n = 20,871) examined for Salmonella between 1996 and 2009 were extracted from the databases of the Central Veterinary Research Laboratory in Dubai and from typed strains (n = 1052) from the Robert Koch Institute, Wernigerode Branch in Germany and analyzed for general and animal-specific trends. Salmonella was isolated from 1,928 (9 %) of the 20,871 samples examined. Among the 1,052 typed strains, most were from camels (n = 232), falcons (n = 166), bustards (n = 101), antelopes (n = 66), and horses (n = 63). The predominant serovars were Salmonella Typhimurium (25 %), Salmonella Kentucky (8 %), followed by Salmonella Frintrop (7 %), and Salmonella Hindmarsh (5 %). When analyzed by animal species, the most frequent serovars in camels were Salmonella Frintrop (28 %) and Salmonella Hindmarsh (21 %), in falcons Salmonella Typhimurium (32 %), in bustards Salmonella Kentucky (19 %), in antelopes Salmonella Typhimurium (9 %), and in horses Salmonella Typhimurium (17 %) and S. Kentucky (16 %). Resistance of all typed Salmonella strains (n = 1052) was most often seen to tetracycline (23 %), streptomycin (22 %), nalidixic acid (18 %), and ampicillin (15 %). These data show trends in the epidemiology of Salmonella in different animal species which can be used as a base for future prevention, control, and therapy strategies.

Demonstration of persistent contamination of a cooked egg product production facility with Salmonella enterica serovar Tennessee and characterization of the persistent strain

DEFF Research Database (Denmark)

Jakociune, D.; Bisgaard, M.; Pedersen, Karl

2014-01-01

Aims: The aim of this study was to investigate whether continuous contamination of light pasteurized egg products with Salmonella enterica serovar Tennessee (S. Tennessee) at a large European producer of industrial egg products was caused by persistent contamination of the production facility......, members of the persistent clone were weak producers of H2S in laboratory medium. S. Tennessee isolated from the case was able to grow better in pasteurized egg product compared with other serovars investigated. Conclusions: It was concluded that the contamination was caused by a persistent strain...... in the production facility and that this strain apparently had adapted to grow in the relevant egg product. Significance and Impact of the Study: S. Tennessee has previously been associated with persistence in hatching facilities. This is the first report of persistent contamination of an egg production facility...

BIOCHEMICAL AND MOLECULAR CHARACTERIZATION OF SALMONELLA-ENTERICA SEROVAR BERTA, AND COMPARISON OF METHODS FOR TYPING

DEFF Research Database (Denmark)

Olsen, J. E.; Brown, D. J.; Baggesen, Dorte Lau

1992-01-01

Strains of Salmonella enterica serovar berta (S. berta) from Denmark and seven other countries have been characterized with the aim of developing a rational typing strategy in connection with outbreak investigations, Biotyping divided the strains into H2S-positive (90 %) and H2S-negative (10...... with restriction enzyme analysis of plasmids seemed to be the most rational typing strategy for S. berta. The results indicated that S. berta strains regardless of geographical source or host are possibly clonal in nature....

Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Infantis Strain SPE101, Isolated from a Chronic Human Infection.

Science.gov (United States)

Iriarte, Andrés; Giner-Lamia, Joaquín; Silva, Claudia; Betancor, Laura; Astocondor, Lizeth; Cestero, Juan J; Ochoa, Theresa; García, Coralith; Puente, José L; Chabalgoity, José A; García-Del Portillo, Francisco

2017-07-20

We report a 4.99-Mb draft genome sequence of Salmonella enterica subsp. enterica serovar Infantis strain SPE101, isolated from feces of a 5-month-old breast-fed female showing diarrhea associated with severe dehydration and malnutrition. The infection prolonged for 6 months despite antibiotic treatment. Copyright © 2017 Iriarte et al.

The microbiological and clinical characteristics of invasive salmonella in gallbladders from cholecystectomy patients in kathmandu, Nepal.

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Sabina Dongol

Full Text Available Gallbladder carriage of invasive Salmonella is considered fundamental in sustaining typhoid fever transmission. Bile and tissue was obtained from 1,377 individuals undergoing cholecystectomy in Kathmandu to investigate the prevalence, characteristics and relevance of invasive Salmonella in the gallbladder in an endemic area. Twenty percent of bile samples contained a Gram-negative organism, with Salmonella Typhi and Salmonella Paratyphi A isolated from 24 and 22 individuals, respectively. Gallbladders that contained Salmonella were more likely to show evidence of acute inflammation with extensive neutrophil infiltrate than those without Salmonella, corresponding with higher neutrophil and lower lymphocyte counts in the blood of Salmonella positive individuals. Antimicrobial resistance in the invasive Salmonella isolates was limited, indicating that gallbladder colonization is unlikely to be driven by antimicrobial resistance. The overall role of invasive Salmonella carriage in the gallbladder is not understood; here we show that 3.5% of individuals undergoing cholecystectomy in this setting have a high concentration of antimicrobial sensitive, invasive Salmonella in their bile. We predict that such individuals will become increasingly important if current transmission mechanisms are disturbed; prospectively identifying these individuals is, therefore, paramount for rapid local and regional elimination.

The value of the Widal test in the diagnosis of Prolonged Septicemic Salmonellosis

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José Roberto Lambertucci

1985-04-01

Full Text Available Twenty patients with prolonged septicemic salmonellosis (Group 1 and 20 with schistosomiasis mansoni (Group 2 were selected for this study. In both groups, the Widal test was done using antigens of the sample Ty 901 (S. typhi. The test was also applied in 6 group 1 patients with antigens prepared from salmonellae isolated from these patients (autoantigens. Titres over 1:200 were considered significant. Ten group 1 patients (50% were positive for antigen "H" and 5 (25% were positive for antigen "O". Three patients with negative "H" and "O" reactions became positive with high titres when using autoantigens. Two other cases maintained the same positive titres and one case showed a fourfold increase in titres when the test was done 'with antigens of the Salmonella isolated. The Widal test was positive in most patients infected with group D Salmonellae. Considering titres above 1:200, all cases were negative in Group 2. The authors conclude that the Widal test has low positivity in prolonged septicemic salmonellosis. The test may be valuable in the diagnosis of this disease when using S. paratyphi "A" and "B" antigens and a mixture of Salmonella antigens taken from other groups.

Antibody response to the lipopolysaccharide and protein antigens of Salmonella typhi during typhoid infection

International Nuclear Information System (INIS)

Tsang, R.S.W.; Chau, P.Y.; Lam, S.K.

1981-01-01

Serum antibody responses to the lipopolysaccharide and protein antigens of S. typhi in typhoid patients were studied using a solid-phase radioimmunoassay technique with 125 I labelled anti-immunoglobulin antibody. Sera from 24 adult typhoid patients and 20 non-typhoid adult controls were compared. As a group, sera from typhoid patients showed increased IgA, IgG and IgM immunoglobulin levels and gave significantly higher anti-LPS and anti-protein antibody titres in all three major immunoglobulin classes than did non-typhoid controls. Levels of antibodies against LPS or protein in sera of typhoid patients were highly variable with a skew distribution. A good correlation was found between antibody titres to the LPS antigen and those to a protein antigen. No correlation, however, was found between the anti-LPS antibody titres measured by radioimmunoassay and the anti-O antibody titres measured by the Widal agglutination test. Titration of anti-LPS or anti-protein antibodies by radioimmunoassay was found to be more sensitive and specific than Widal test for the serological diagnosis of typhoid fever. The advantages of measuring antibody response by radioimmunoassay over conventional Widal test are discussed. (author)

[Construction of the eukaryotic recombinant vector and expression of the outer membrane protein LipL32 gene from Leptospira serovar Lai].

Science.gov (United States)

Huang, Bi; Bao, Lang; Zhong, Qi; Shang, Zheng-ling; Zhang, Hui-dong; Zhang, Ying

2008-02-01

To construct the eukaryotic experssion vector of LipL32 gene from Leptospira serovar Lai and express the recombinant plasmid in COS-7 cell. The LipL32 gene was amplified from Leptospira strain 017 genomic DNA by PCR and cloned into pcDNA3.1, through restriction nuclease enzyme digestion. Then the recombinant plasmid was transformed into E.coli DH5alpha. After identified by nuclease digestion, PCR and sequencing analysis, the recombinant vector was transfected into COS-7 cell with lipsome. The expression of the target gene was detected by RT-PCR and Western blot. The eukaryotic experssion vector pcDNA3.1-LipL32 was successfully constructed and stably expressed in COS-7 cell. The eukaryotic recombinant vector of outer membrane protein LipL32 gene from Leptospira serovar Lai can be expressed in mammalian cell, which provides an experimental basis for the application of the Leptospira DNA vaccine.

Draft Genome Sequences of Four Salmonella enterica subsp. enterica Serovar Enteritidis Strains Implicated in Infections of Avian and Human Hosts

KAUST Repository

An, Ran; Lin, Pengpeng; Bougouffa, Salim; Essack, Magbubah; Boxrud, David; Bajic, Vladimir B.; Vidovic, Sinisa

2018-01-01

Salmonella enterica subsp. enterica serovar Enteritidis is a wide-host-range pathogen. Occasionally, it is involved in invasive infections, leading to a high mortality rate. Here, we present the draft genome sequences of four S Enteritidis strains obtained from human and avian hosts that had been involved in bacteremia, gastroenteritis, and primary infections.

Draft Genome Sequences of Four Salmonella enterica subsp. enterica Serovar Enteritidis Strains Implicated in Infections of Avian and Human Hosts

KAUST Repository

An, Ran

2018-01-24

Salmonella enterica subsp. enterica serovar Enteritidis is a wide-host-range pathogen. Occasionally, it is involved in invasive infections, leading to a high mortality rate. Here, we present the draft genome sequences of four S Enteritidis strains obtained from human and avian hosts that had been involved in bacteremia, gastroenteritis, and primary infections.

Plasmid fingerprinting and virulence gene detection among indigenous strains of salmonella enterica serovar enteritidis

International Nuclear Information System (INIS)

Sajid, S.U.; Schwarz, S.

2009-01-01

Salmonella enterica serovar Enteritidis is an important frequently reported zoonotic pathogen and a common cause of human gastroenteritis worldwide. The highly conserved Serospecific plasmids (SSPs) and Salmonella plasmid virulence (Spv) genes have been shown to mediate extra-intestinal colonization and systemic infection. The objective of current study was to document the presence of SSPs and SpvB/SpvC genes prevailing in the indigenous population of serovar Enteritidis. A total of 48 epidemiologically unrelated strains of Salmonella enteritidis were included in the study. Preparation of plasmids DNA suitable for endonuclease digestion and separation of respective fragments by agarose gel electrophoresis followed previously described protocols. The plasmids of Escherichia coli V517, 1-kbp ladder, and lambda DNA HindIII fragments served as DNA size standards. Transfer of DNA fragments from agarose gels to nitrocellulose membranes was achieved by capillary blot procedure. An ECL labeled 3.6 kbp HindIII fragment of plasmid PRQ 51 was used as probe for SpvB/SpvC gene detection. Plasmid DNA fingerprinting revealed the presence of two different profiles of approximately 55 kbp and 90 kbp and were identified as virulence plasmids by DNA hybridization. The SpvB/SpvC genes were located on HindIII fragments of 3.6 kbp in each of the two types of virulence plasmids. The study confirms the presence of SSPs and SpvB/SpvC genes in indigenous strains of S. enteritidis isolated from Northern Punjab area of Pakistan and substantiate the previous data on such findings from other parts of the world. (author)

Multilocus Sequence Typing of the Clinical Isolates of Salmonella Enterica Serovar Typhimurium in Tehran Hospitals

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Reza Ranjbar

2017-09-01

Full Text Available Background: Salmonella enterica serovar Typhimurium is one of the most important serovars of Salmonella enterica and is associated with human salmonellosis worldwide. Many epidemiological studies have focused on the characteristics of Salmonella Typhimurium in many countries as well as in Asia. This study was conducted to investigate the genetic characteristics of Salmonella Typhimurium using multilocus sequence typing (MLST. Methods: Clinical samples (urine, blood, and stool were collected from patients, who were admitted to 2 hospitals in Tehran between April and September, 2015. Salmonella Typhimurium strains were identified by conventional standard biochemical and serological testing. The antibiotic susceptibility patterns of the Salmonella Typhimurium isolates against 16 antibiotics was determined using the disk diffusion assay. The clonal relationship between the strains of Salmonella Typhimurium was analyzed using MLST. Results: Among the 68 Salmonella isolates, 31% (n=21 were Salmonella Typhimurium. Of the total 21 Salmonella Typhimurium isolates, 76% (n=16 were multidrug-resistant and showed resistance to 3 or more antibiotic families. The Salmonella Typhimurium isolates were assigned to 2 sequence types: ST19 and ST328. ST19 was more common (86%. Both sequence types were further assigned to 1 eBURST group. Conclusion: This is the first study of its kind in Iran to determine the sequence types of the clinical isolates of Salmonella Typhimurium in Tehran hospitals using MLST. ST19 was detected as the major sequence type of Salmonella Typhimurium.

Molecular characterization of Salmonella enterica serovar 4,[5],12:i:- DT193 ASSuT strains from two outbreaks in Italy

DEFF Research Database (Denmark)

Barco, Lisa; Ramon, Elena; Cortini, Enzo

2014-01-01

Abstract Salmonella enterica subsp. enterica serovar 4,[5],12:i:- DT193 is recognized as an emerging monophasic variant of Salmonella Typhimurium in many European countries. Resistance to ampicillin, streptomycin, sulphonamides, and tetracycline (R-type ASSuT) is described as one of the most comm...

Fifteen years of successful spread of Salmonella enterica serovar Mbandaka clone ST413 in Poland and its public health consequences

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Andrzej Hoszowski

2016-06-01

Full Text Available In the 1990s, [i]Salmonella enterica[/i] serovar (S. Mbandaka occurred in feed and poultry in Poland. In the following years, the serovar also gained epidemiological importance in other EU countries. The objectives of current study were to evaluate the genetic relationship of contemporary S. Mbandaka with isolates originating from the beginning of the epidemics, and to assess the contribution of poultry as the source of infections in humans. Seventy S. Mbandaka isolated mainly in 2009 – 2010 from humans, poultry, food, and feed were typed with API ID32 [sup]®[/sup], MIC, plasmid profiling, PFGE, and MLST. PCR and sequencing were used to identify plasmid mediated quinolone and cephalosporin resistance mechanisms. Six biochemical profiles were identified and 59 of S. Mbandaka proved to be susceptible to the applied antimicrobials. Eight strains carried plasmids and a few of them were positive for [i]bla[/i][sub]CMY-2[/sub] and [i]qnr[/i]S1 genes. Two clusters of 15 [i]XbaI[/i]-PFGE profiles with similarity of 77.5% were found. The first cluster, gathered 7 profiles involving historical isolates and several contemporary non-human S. Mbandaka. The predominant profile in the second cluster consisted of 28 human and 1 broiler isolate. MLST analysis showed sequence type ST413 occurring among all tested isolates. The identification of close genetic relationships between S. Mbandaka of human and poultry origin indicates animals as a primal human infection route. Despite [i]Salmonella [/i]control programmes, the S. Mbandaka ST413 clone has been circulating for several years in Poland. [i]Salmonella[/i] control polices in food production chain should be continuously updated to target serovars of major epidemiological importance. Resistance noted in S. Mbandaka to such antimicrobials as fluoroquinolones and cephalosporins may hinder public health.

Effects of interferon gamma on Chlamydia trachomatis serovar A and L2 protein expression investigated by two-dimensional gel electrophoresis

DEFF Research Database (Denmark)

Shaw, A; Christiansen, Gunna; Birkelund, Svend

1999-01-01

]methionine and two-dimensional gel electrophoresis with immobilized pH gradients in order to investigate changes in the protein expression of C. trachomatis serovar A and L2 caused by treatment with IFN-gamma. In contrast to what was observed in C. trachomatis L2, our results showed that, in C. trachomatis A, down...

Development of ELISAs for diagnosis of acute typhoid fever in Nigerian children.

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Jiin Felgner

2017-06-01

Full Text Available Improved serodiagnostic tests for typhoid fever (TF are needed for surveillance, to facilitate patient management, curb antibiotic resistance, and inform public health programs. To address this need, IgA, IgM and IgG ELISAs using Salmonella enterica serovar Typhi (S. Typhi lipopolysaccharide (LPS and hemolysin E (t1477 protein were conducted on 86 Nigerian pediatric TF and 29 non-typhoidal Salmonella (NTS cases, 178 culture-negative febrile cases, 28 "other" (i.e., non-Salmonella pediatric infections, and 48 healthy Nigerian children. The best discrimination was achieved between TF and healthy children. LPS-specific IgA and IgM provided receiver operator characteristic areas under the curve (ROC AUC values of 0.963 and 0.968, respectively, and 0.978 for IgA+M combined. Similar performance was achieved with t1477-specific IgA and IgM (0.968 and 0.968, respectively; 0.976 combined. IgG against LPS and t1477 was less accurate for discriminating these groups, possibly as a consequence of previous exposure, although ROC AUC values were still high (0.928 and 0.932, respectively. Importantly, discrimination between TF and children with other infections was maintained by LPS-specific IgA and IgM (AUC = 0.903 and 0.934, respectively; 0.938 combined, and slightly reduced for IgG (0.909, while t1477-specific IgG performed best (0.914. A similar pattern was seen when comparing TF with other infections from outside Nigeria. The t1477 may be recognized by cross-reactive antibodies from other acute infections, although a robust IgG response may provide some diagnostic utility in populations where incidence of other infections is low, such as in children. The data are consistent with IgA and IgM against S. Typhi LPS being specific markers of acute TF.

Validation of Baking To Control Salmonella Serovars in Hamburger Bun Manufacturing, and Evaluation of Enterococcus faecium ATCC 8459 and Saccharomyces cerevisiae as Nonpathogenic Surrogate Indicators.

Science.gov (United States)

Channaiah, Lakshmikantha H; Holmgren, Elizabeth S; Michael, Minto; Sevart, Nicholas J; Milke, Donka; Schwan, Carla L; Krug, Matthew; Wilder, Amanda; Phebus, Randall K; Thippareddi, Harshavardhan; Milliken, George

2016-04-01

This study was conducted to validate a simulated commercial baking process for hamburger buns to destroy Salmonella serovars and to determine the appropriateness of using nonpathogenic surrogates (Enterococcus faecium ATCC 8459 or Saccharomyces cerevisiae) for in-plant process validation studies. Wheat flour was inoculated (∼6 log CFU/g) with three Salmonella serovars (Typhimurium, Newport, or Senftenberg 775W) or with E. faecium. Dough was formed, proofed, and baked to mimic commercial manufacturing conditions. Buns were baked for up to 13 min in a conventional oven (218.3°C), with internal crumb temperature increasing to ∼100°C during the first 8 min of baking and remaining at this temperature until removal from the oven. Salmonella and E. faecium populations were undetectable by enrichment (>6-log CFU/g reductions) after 9.0 and 11.5 min of baking, respectively, and ≥5-log-cycle reductions were achieved by 6.0 and 7.75 min, respectively. D-values of Salmonella (three-serovar cocktail) and E. faecium 8459 in dough were 28.64 and 133.33, 7.61 and 55.67, and 3.14 and 14.72 min at 55, 58, and 61°C, respectively, whereas D-values of S. cerevisiae were 18.73, 5.67, and 1.03 min at 52, 55, and 58°C, respectivly. The z-values of Salmonella, E. faecium, and S. cerevisiae were 6.58, 6.25, and 4.74°C, respectively. A high level of thermal lethality was observed for baking of typical hamburger bun dough, resulting in rapid elimination of high levels of the three-strain Salmonella cocktail; however, the lethality and microbial destruction kinetics should not be extrapolated to other bakery products without further research. E. faecium demonstrated greater thermal resistance compared with Salmonella during bun baking and could serve as a conservative surrogate to validate thermal process lethality in commercial bun baking operations. Low thermal tolerance of S. cerevisiae relative to Salmonella serovars limits its usefulness as a surrogate for process validations.

Salmonella Bacteremia Among Children in Central and Northwest Nigeria, 2008–2015

Science.gov (United States)

Obaro, Stephen K.; Hassan-Hanga, Fatimah; Olateju, Eyinade K.; Umoru, Dominic; Lawson, Lovett; Olanipekun, Grace; Ibrahim, Sadeeq; Munir, Huda; Ihesiolor, Gabriel; Maduekwe, Augustine; Ohiaeri, Chinatu; Adetola, Anthony; Shetima, Denis; Jibir, Binta W.; Nakaura, Hafsat; Kocmich, Nicholas; Ajose, Therasa; Idiong, David; Masokano, Kabir; Ifabiyi, Adeyemi; Ihebuzor, Nnenna; Chen, Baojiang; Meza, Jane; Akindele, Adebayo; Rezac-Elgohary, Amy; Olaosebikan, Rasaq; Suwaid, Salman; Gambo, Mahmoud; Alter, Roxanne; Davies, Herbert D.; Fey, Paul D.

2015-01-01

Background. Etiologic agents of childhood bacteremia remain poorly defined in Nigeria. The absence of such data promotes indiscriminate use of antibiotics and delays implementation of appropriate preventive strategies. Methods. We established diagnostic laboratories for bacteremia surveillance at regional sites in central and northwest Nigeria. Acutely ill children aged <5 years with clinically suspected bacteremia were evaluated at rural and urban clinical facilities in the Federal Capital Territory, central region and in Kano, northwest Nigeria. Blood was cultured using the automated Bactec incubator system. Results. Between September 2008 and April 2015, we screened 10 133 children. Clinically significant bacteremia was detected in 609 of 4051 (15%) in the northwest and 457 of 6082 (7.5%) in the central region. Across both regions, Salmonella species account for 24%–59.8% of bacteremias and are the commonest cause of childhood bacteremia, with a predominance of Salmonella enterica serovar Typhi. The prevalence of resistance to ampicillin, chloramphenicol, and cotrimoxazole was 38.11%, with regional differences in susceptibility to different antibiotics but high prevalence of resistance to readily available oral antibiotics. Conclusions. Salmonella Typhi is the leading cause of childhood bacteremia in central Nigeria. Expanded surveillance is planned to define the dynamics of transmission. The high prevalence of multidrug-resistant strains calls for improvement in environmental sanitation in the long term and vaccination in the short term. PMID:26449948

A Phylogenetic and Phenotypic Analysis of Salmonella enterica Serovar Weltevreden, an Emerging Agent of Diarrheal Disease in Tropical Regions.

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Carine Makendi

2016-02-01

Full Text Available Salmonella enterica serovar Weltevreden (S. Weltevreden is an emerging cause of diarrheal and invasive disease in humans residing in tropical regions. Despite the regional and international emergence of this Salmonella serovar, relatively little is known about its genetic diversity, genomics or virulence potential in model systems. Here we used whole genome sequencing and bioinformatics analyses to define the phylogenetic structure of a diverse global selection of S. Weltevreden. Phylogenetic analysis of more than 100 isolates demonstrated that the population of S. Weltevreden can be segregated into two main phylogenetic clusters, one associated predominantly with continental Southeast Asia and the other more internationally dispersed. Subcluster analysis suggested the local evolution of S. Weltevreden within specific geographical regions. Four of the isolates were sequenced using long read sequencing to produce high quality reference genomes. Phenotypic analysis in Hep-2 cells and in a murine infection model indicated that S. Weltevreden were significantly attenuated in these models compared to the classical S. Typhimurium reference strain SL1344. Our work outlines novel insights into this important emerging pathogen and provides a baseline understanding for future research studies.

A new multivalent (DHPPi/L4R) canine combination vaccine prevents infection, shedding and clinical signs following experimental challenge with four Leptospira serovars.

Science.gov (United States)

Wilson, Stephen; Stirling, Catrina; Thomas, Anne; King, Vickie; Plevová, Edita; Chromá, Ludmila; Siedek, Elisabeth; Illambas, Joanna; Salt, Jeremy; Sture, Gordon

2013-06-28

Although effective vaccines have been developed against the common Leptospira serovars, they are still reported in clinical cases, while others are increasingly prevalent. The results from four challenge studies following vaccination of dogs with a new combination vaccine (DHPPi/L4R) containing inactivated L. serovars, L. canicola, L. icterohaemorrhagiae, L. bratislava and L. grippotyphosa conducted to satisfy the requirements of the European Pharmacopoeia monograph (01/2008:0447), are reported. Six week old dogs received two vaccinations, three weeks apart, and were challenged 25 days later with different isolates of the L. serovars. Clinical observations were recorded, and blood, urine and tissue samples were collected for analysis. Following challenge, non-vaccinated dogs demonstrated various clinical signs, while no vaccinated dogs were affected; significant differences in mean clinical scores were observed. Measurable antibody titres to each Leptospira antigen were seen in vaccinated dogs 21 days following the first vaccination, with further increases in antibody titres observed following challenge with the respective Leptospira strain. Non-vaccinated dogs remained seronegative until challenge. Leptospira were re-isolated from the blood, urine, kidney and liver of all non-vaccinated dogs following challenge. In contrast no vaccinated dogs had Leptospira re-isolated from the same tissues. Significant differences were seen in number of days with positive isolation (blood and urine) and in number of dogs with positive samples (kidney and liver). In conclusion, vaccination of dogs with the new vaccine induces protective immunity 25 days after second vaccination with protection against infection, renal infection and clinical signs following challenge. Copyright © 2013 Elsevier Ltd. All rights reserved.

In vitro and in vivo probiotic assessment of Leuconostoc mesenteroides P45 isolated from pulque, a Mexican traditional alcoholic beverage.

Science.gov (United States)

Giles-Gómez, Martha; Sandoval García, Jorge Giovanni; Matus, Violeta; Campos Quintana, Itzia; Bolívar, Francisco; Escalante, Adelfo

2016-01-01

Pulque is a Mexican traditional alcoholic, non-distilled, fermented beverage produced by the fermentation of the sap, known as aguamiel, extracted from several maguey (Agave) species. Pulque has traditionally been considered a healthy beverage due to its nutrient content and also a traditional medicine for the treatment of gastrointestinal disorders and intestinal infections. During pulque fermentation, the development of acidity, alcohol and viscosity define its final sensorial properties, developing an enriched environment where dominant lactic acid bacteria (LAB), including diverse Leuconostoc species, are present. Because traditional pulque is consumed directly from the fermentation vessel, the naturally associated LAB are ingested and reach the human small intestine alive. Here, we report the in vitro and in vivo probiotic assessment of Leuconostoc mesenteroides strain P45 isolated from pulque. This isolated LAB species exhibited lysozyme, acid (pH 3.5) and bile salts (0.1 and 0.3 % oxgall) resistance. Antibacterial activity against the pathogens Listeria monocytogenes, enteropathogenic Escherichia coli, Salmonella enterica serovar Typhi and S. enterica serovar Typhimurium were observed in assays involving cell-to-cell contact, cell-free 2× concentrated supernatants and cell-to-cell contact under exopolysaccharide-producing conditions. The in vivo probiotic assessment showed an anti-infective activity of L. mesenteroides P45 against S. enterica serovar Typhimurium in challenged male and female BALB/c mice. Analysis of the available genome sequence of strain P45 allowed identified a pre-bacteriocin coding gene and six peptidoglycan hydrolase enzymes, probably involved in the antimicrobial activity of this strain. The results presented in this study support some potential microbial mechanisms associated with the beneficial effects on human health of this LAB involved in the fermentation of pulque.

Comparison of Methods of Extracting Salmonella enterica Serovar Enteritidis DNA from Environmental Substrates and Quantification of Organisms by Using a General Internal Procedural Control

NARCIS (Netherlands)

Klerks, M.M.; Bruggen, van A.H.C.; Zijlstra, C.; Donnikov, M.; Vos, de R.

2006-01-01

This paper compares five commercially available DNA extraction methods with respect to DNA extraction efficiency of Salmonella enterica serovar Enteritidis from soil, manure, and compost and uses an Escherichia coli strain harboring a plasmid expressing green fluorescent protein as a general

Cloning, expression, and homology modeling of GroEL protein from Leptospira interrogans serovar autumnalis strain N2.

Science.gov (United States)

Natarajaseenivasan, Kalimuthusamy; Shanmughapriya, Santhanam; Velineni, Sridhar; Artiushin, Sergey C; Timoney, John F

2011-10-01

Leptospirosis is an infectious bacterial disease caused by Leptospira species. In this study, we cloned and sequenced the gene encoding the immunodominant protein GroEL from L. interrogans serovar Autumnalis strain N2, which was isolated from the urine of a patient during an outbreak of leptospirosis in Chennai, India. This groEL gene encodes a protein of 60 kDa with a high degree of homology (99% similarity) to those of other leptospiral serovars. Recombinant GroEL was overexpressed in Escherichia coli. Immunoblot analysis indicated that the sera from confirmed leptospirosis patients showed strong reactivity with the recombinant GroEL while no reactivity was observed with the sera from seronegative control patient. In addition, the 3D structure of GroEL was constructed using chaperonin complex cpn60 from Thermus thermophilus as template and validated. The results indicated a Z-score of -8.35, which is in good agreement with the expected value for a protein. The superposition of the Ca traces of cpn60 structure and predicted structure of leptospiral GroEL indicates good agreement of secondary structure elements with an RMSD value of 1.5 Å. Further study is necessary to evaluate GroEL for serological diagnosis of leptospirosis and for its potential as a vaccine component. Copyright © 2011 Beijing Genomics Institute. Published by Elsevier Ltd. All rights reserved.

Serovar 4b complex predominates among Listeria monocytogenes isolates from imported aquatic products in China.

Science.gov (United States)

Chen, Jianshun; Chen, Qiaomiao; Jiang, Jianjun; Hu, Hongxia; Ye, Jiangbo; Fang, Weihuan

2010-01-01

Listeria monocytogenes, the causative organism of listeriosis, is primarily transmitted to humans through contaminated food. In this study, we examined 1275 batches of aquatic products imported from 29 countries and found that 36 batches from 8 countries were contaminated by Listeria (2.8%), with L. monocytogenes accounting for 2.6% (33/1275) and L. innocua for 0.2% (3/1275). Of the 23 selected L. monocytogenes isolates (from the 33 identified), 15 (65.2%) were of serovar 4b complex (4b, 4d, or 4e), three (13.0%) of 1/2a or 3a, four (17.4%) of 1/2b or 3b, and one (4.4%) of 1/2c or 3c. Notably, four of the 23 isolates belonged to epidemic clone I (ECI) and another four were associated with epidemic clone II (ECII), two highly clonal 4b clusters responsible for most of the documented listeriosis outbreaks. In the multilocus sequence typing scheme based on the concatenated genes gyrB-dapE-hisJ-sigB-ribC-purM-betL-gap-tuf, serovar 4b complex isolates from imported aquatic products exhibited significant genetic diversity. While the four ECI isolates were genetically related to those from Chinese diseased animals, both lacking one proline-rich repeat of ActA, the four ECII isolates were located between 1/2b or 3b strains. As the L. monocytogenes isolates from imported aquatic products possessed a nearly complete set of major infection-related genes, they demonstrated virulence potential in mouse model.

Regulation of the Two-Component Regulator CpxR on Aminoglycosides and β-lactams Resistance in Salmonella enterica Serovar Typhimurium

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Hui eHuang

2016-04-01

Full Text Available The two-component signal transduction system CpxAR is especially widespread in Gram-negative bacteria. It has been reported that CpxAR contributes to the multidrug resistance (MDR in Escherichia coli. CpxR is a response regulator in the two-component CpxAR system. The aim of this study was to explore the role of cpxR in the MDR of S. enterica serovar Typhimurium. The minimal inhibitory concentrations (MICs of various antibiotics commonly used in veterinary medicine for strains JS (a multidrug-susceptible standard strain of S. enterica serovar Typhimurium, JS△cpxR, JS△cpxR/pcpxR, JS△cpxR/pcpxR＊, JS△cpxR△acrB, JS△cpxR△acrB/pcpxR, JS△cpxR△acrB/pcpxR＊, 9 S. enterica serovar Typhimurium isolates (SH1–9, and SH1–9△cpxR were determined by the 2-fold broth microdilution method. The relative mRNA expression levels of ompF, ompC, ompW, ompD, tolC, acrB, acrD, acrF, mdtA, marA, and soxS in strains JS, JS△cpxR, and JS△cpxR/pcpxR were detected by real-time PCR. The results showed 2- to 4-fold decreases in the MICs of amikacin (AMK, gentamycin (GEN, apramycin (APR, neomycin (NEO, ceftriaxone (CRO, ceftiofur (CEF, and cefquinome (CEQ for strain JS△cpxR, as compared to those for the parental strain JS. Likewise, SH1–9△cpxR were found to have 2- to 8-fold reduction in resistance to the above antibiotics, except for NEO, as compared to their parental strains SH1–9. Furthermore, 2- to 4-fold further decreases in the MICs of AMK, GEN, APR, and CEF for strain JS△cpxR△acrB were observed, as compared to those for strain JS△acrB. In addition, CpxR overproduction in strain JS△cpxR led to significant decreases in the mRNA expression levels of ompF, ompC, ompW, ompD, tolC, acrB, marA, and soxS, and significant increases in those of stm3031 and stm1530. Notably, after all strains were induced simultaneously by GEN to the 15th passage at subinhibitory concentrations, strain JS△cpxR/pcpxR showed significant increases in m

Expression and function of S100A8/A9 (calprotectin) in human typhoid fever and the murine Salmonella model.

Science.gov (United States)

De Jong, Hanna K; Achouiti, Ahmed; Koh, Gavin C K W; Parry, Christopher M; Baker, Stephen; Faiz, Mohammed Abul; van Dissel, Jaap T; Vollaard, Albert M; van Leeuwen, Ester M M; Roelofs, Joris J T H; de Vos, Alex F; Roth, Johannes; van der Poll, Tom; Vogl, Thomas; Wiersinga, Willem Joost

2015-04-01

Typhoid fever, caused by the Gram-negative bacterium Salmonella enterica serovar Typhi, is a major cause of community-acquired bacteremia and death worldwide. S100A8 (MRP8) and S100A9 (MRP14) form bioactive antimicrobial heterodimers (calprotectin) that can activate Toll-like receptor 4, promoting lethal, endotoxin-induced shock and multi-organ failure. We aimed to characterize the expression and function of S100A8/A9 in patients with typhoid fever and in a murine invasive Salmonella model. S100A8/A9 protein levels were determined in acute phase plasma or feces from 28 Bangladeshi patients, and convalescent phase plasma from 60 Indonesian patients with blood culture or PCR-confirmed typhoid fever, and compared to 98 healthy control subjects. To functionally characterize the role of S100A8/A9, we challenged wildtype (WT) and S100A9-/- mice with S. Typhimurium and determined bacterial loads and inflammation 2- and 5- days post infection. We further assessed the antimicrobial function of recombinant S100A8/A9 on S. Typhimurium and S. Typhi replication in vitro. Typhoid fever patients demonstrated a marked increase of S100A8/A9 in acute phase plasma and feces and this increases correlated with duration of fever prior to admission. S100A8/A9 directly inhibited the growth of S. Typhimurium and S. Typhi in vitro in a dose and time dependent fashion. WT mice inoculated with S. Typhimurium showed increased levels of S100A8/A9 in both the liver and the systemic compartment but S100A9-/- mice were indistinguishable from WT mice with respect to bacterial growth, survival, and inflammatory responses, as determined by cytokine release, histopathology and organ injury. S100A8/A9 is markedly elevated in human typhoid, correlates with duration of fever prior to admission and directly inhibits the growth of S. Typhimurium and S. Typhi in vitro. Despite elevated levels in the murine invasive Salmonella model, S100A8/A9 does not contribute to an effective host response against S

Expression and function of S100A8/A9 (calprotectin in human typhoid fever and the murine Salmonella model.

Directory of Open Access Journals (Sweden)

Hanna K De Jong

2015-04-01

Full Text Available Typhoid fever, caused by the Gram-negative bacterium Salmonella enterica serovar Typhi, is a major cause of community-acquired bacteremia and death worldwide. S100A8 (MRP8 and S100A9 (MRP14 form bioactive antimicrobial heterodimers (calprotectin that can activate Toll-like receptor 4, promoting lethal, endotoxin-induced shock and multi-organ failure. We aimed to characterize the expression and function of S100A8/A9 in patients with typhoid fever and in a murine invasive Salmonella model.S100A8/A9 protein levels were determined in acute phase plasma or feces from 28 Bangladeshi patients, and convalescent phase plasma from 60 Indonesian patients with blood culture or PCR-confirmed typhoid fever, and compared to 98 healthy control subjects. To functionally characterize the role of S100A8/A9, we challenged wildtype (WT and S100A9-/- mice with S. Typhimurium and determined bacterial loads and inflammation 2- and 5- days post infection. We further assessed the antimicrobial function of recombinant S100A8/A9 on S. Typhimurium and S. Typhi replication in vitro. Typhoid fever patients demonstrated a marked increase of S100A8/A9 in acute phase plasma and feces and this increases correlated with duration of fever prior to admission. S100A8/A9 directly inhibited the growth of S. Typhimurium and S. Typhi in vitro in a dose and time dependent fashion. WT mice inoculated with S. Typhimurium showed increased levels of S100A8/A9 in both the liver and the systemic compartment but S100A9-/- mice were indistinguishable from WT mice with respect to bacterial growth, survival, and inflammatory responses, as determined by cytokine release, histopathology and organ injury.S100A8/A9 is markedly elevated in human typhoid, correlates with duration of fever prior to admission and directly inhibits the growth of S. Typhimurium and S. Typhi in vitro. Despite elevated levels in the murine invasive Salmonella model, S100A8/A9 does not contribute to an effective host response

Characterization of a linear epitope on Chlamydia trachomatis serovar L2 DnaK-like protein

DEFF Research Database (Denmark)

Ozkokmen, D; Birkelund, Svend; Christiansen, Gunna

1994-01-01

A cytoplasmic 75-kDa immunogen from Chlamydia trachomatis serovar L2 has previously been characterized as being similar to the Escherichia coli heat shock protein DnaK. We have localized a linear epitope for one monoclonal antibody specific for C. trachomatis DnaK. By use of a recombinant DNA...... technique, the epitope was limited to 14 amino acids. With synthetic peptides, the epitope was further limited to eight amino acids. Six of these amino acids are conserved in bovine HSP70, which has a known three-dimensional structure. The amino acid sequence homologous to the epitope is located in a linear...

Open study of short course Fleroxacin for Typhoid and Paratyphoid Fever

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R. H.H. Nelwan

2002-03-01

Full Text Available The objective of this study was to evaluate clinical and bacteriological effect of short course fleroxacin in uncomplicated typhoid and paratyphoid fever patients. Four hundred mg of fleroxacin was given oraly once daily for a period of 3 to 5 days. The diagnosis of typhoid and paratyphoid fever was established by clinical picture as well as blood culture or Widal serology test. Thirty patients in whom the clinical picture was confirmed as a typhoid or paratyphoid infection were eligible for this investigation. They consisted of 15 males and 15 females ranging in age from 18-38 years average 27.5 years of whom 18 were diagnosed by blood culture consisting of 16 S.typhi positive cases and two S.paratyphi A, while 12 other cases were positively confirmed by serial Widal agglutination serology. These cases suffered from fever between 3-14 days with a minimum recorded body temperature elevation of 38.5 degrees Celsius. Clinical response with defervescence of fever was obtained in the positive blood culture group within 3 days (8 patients including 2 cases positive for S.paratyphi A and within two additional days (5 days in the remaining 10 cases. In the twelve cases with a positive serology for typhoid fever a clinical response was obtained for defervescence within 3 days (6 cases with 4 of these cases were on 3 days of fleroxacin and 2 cases on 5 days of fleroxacin. In the remaining 6 serologic positive cases fever resolved after 4-6 days with an average of 5 days with one on 3 days of fleroxacin and the rest (5 cases on 5 days of fleroxacin. All positive blood culture cases reverted to negative after the fleroxacin course. No relapse or carrier state was recorded in this serie. It may be concluded that a 3 to 5 days closely monitored course of fleroxacin has excellent clinical as well as bacteriological efficacy in noncomplicated typhoid and paratyphoid fever. (Med J Indones 2002; 11: 41-7Keywords: fluoroquinolones, enteric infections, short

A highly sensitive, multiplex broad-spectrum PCR-DNA-enzyme immunoassay and reverse hybridization assay for rapid detection and identification of Chlamydia trachomatis serovars.

NARCIS (Netherlands)

Quint, K.D.; Doorn, L.J. van; Kleter, B.; Koning, M.N. de; Munckhof, H.A. van den; Morre, S.A.; Harmsel, B. ter; Weiderpass, E.; Harbers, G.; Melchers, W.J.G.; Quint, W.G.V.

2007-01-01

Chlamydia trachomatis (Ct) comprises distinct serogroups and serovars. The present study evaluates a novel Ct amplification, detection, and genotyping method (Ct-DT assay). The Ct-DT amplification step is a multiplex broad-spectrum PCR for the cryptic plasmid and the VD2-region of ompl. The Ct-DT

Genome and Transcriptome Adaptation Accompanying Emergence of the Definitive Type 2 Host-Restricted Salmonella enterica Serovar Typhimurium Pathovar

OpenAIRE

Kingsley, Robert A.; Kay, Sally; Connor, Thomas; Barquist, Lars; Sait, Leanne; Holt, Kathryn E.; Sivaraman, Karthi; Wileman, Thomas; Goulding, David; Clare, Simon; Hale, Christine; Seshasayee, Aswin; Harris, Simon; Thomson, Nicholas R.; Gardner, Paul

2013-01-01

Salmonella enterica serovar Typhimurium definitive type 2 (DT2) is host restricted to Columba livia (rock or feral pigeon) but is also closely related to S. Typhimurium isolates that circulate in livestock and cause a zoonosis characterized by gastroenteritis in humans. DT2 isolates formed a distinct phylogenetic cluster within S. Typhimurium based on whole-genome-sequence polymorphisms. Comparative genome analysis of DT2 94-213 and S. Typhimurium SL1344, DT104, and D23580 identified few diff...

Identification of lymphogranuloma venereum-associated Chlamydia trachomatis serovars by fluorescence in situ hybridisation--a proof-of-principle analysis.

Science.gov (United States)

Frickmann, Hagen; Essig, Andreas; Poppert, Sven

2014-04-01

We describe a proof-of-principle evaluation of a fluorescence in situ hybridisation (FISH) procedure to identify Chlamydia trachomatis serovars L1-L3, the causative agents of lymphogranuloma venereum, in cell cultures based on newly designed DNA probes. Rapid and easy-to-perform FISH could facilitate the diagnosis of lymphogranuloma venereum without nucleic acid amplification or serotyping, but requires broader evaluation studies, for example, in tropical high-endemicity regions. © 2014 John Wiley & Sons Ltd.

Leptospira santorosai serovar shermani detergent extract induces an increase in fibronectin production through a toll-like receptor 2-mediated pathway

OpenAIRE

Tian, Ya-Chung; Hung, Cheng-Chieh; Li, Yi-Jung; Chen, Yung-Chang; Chang, Ming-Yang; Yen, Tzung-Hai; Hsu, Hsiang-Hao; Wu, Mai-Szu; Phillips, Aled Owain; Yang, Chih-Wei

2011-01-01

Leptospirosis can activate inflammatory responses through Toll-like receptors (TLRs) and may cause renal tubulointerstitial fibrosis characterized by the accumulation of extracellular matrix (ECM). We have previously demonstrated that Leptospira santorosai serovar Shermani detergent extract stimulates ECM accumulation in vitro. The aim of this study was to examine the mechanistic basis of these previous observations and, in particular, to examine the potential involvement of TLRs. The additio...

Expression and crystallization of SeDsbA, SeDsbL and SeSrgA from Salmonella enterica serovar Typhimurium

International Nuclear Information System (INIS)

Jarrott, R.; Shouldice, S. R.; Gunčar, G.; Totsika, M.; Schembri, M. A.; Heras, B.

2010-01-01

The cloning, purification, crystallization and preliminary crystallographic studies of three DsbA-like proteins present in S. enterica serovar Typhimurium, SeDsbA, SeDsbL and SeSrgA, are reported. Pathogens require protein-folding enzymes to produce functional virulence determinants. These foldases include the Dsb family of proteins, which catalyze oxidative folding in bacteria. Bacterial disulfide catalytic processes have been well characterized in Escherichia coli K-12 and these mechanisms have been extrapolated to other organisms. However, recent research indicates that the K-12 complement of Dsb proteins is not common to all bacteria. Importantly, many pathogenic bacteria have an extended arsenal of Dsb catalysts that is linked to their virulence. To help to elucidate the process of oxidative folding in pathogens containing a wide repertoire of Dsb proteins, Salmonella enterica serovar Typhimurium has been focused on. This Gram-negative bacterium contains three DsbA proteins: SeDsbA, SeDsbL and SeSrgA. Here, the expression, purification, crystallization and preliminary diffraction analysis of these three proteins are reported. SeDsbA, SeDsbL and SeSrgA crystals diffracted to resolution limits of 1.55, 1.57 and 2.6 Å and belonged to space groups P2 1 , P2 1 2 1 2 and C2, respectively

A Constitutively Mannose-Sensitive Agglutinating Salmonella enterica subsp. enterica Serovar Typhimurium Strain, Carrying a Transposon in the Fimbrial Usher Gene stbC, Exhibits Multidrug Resistance and Flagellated Phenotypes

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Kuan-Hsun Wu

2012-01-01

Full Text Available Static broth culture favors Salmonella enterica subsp. enterica serovar Typhimurium to produce type 1 fimbriae, while solid agar inhibits its expression. A transposon inserted in stbC, which would encode an usher for Stb fimbriae of a non-flagellar Salmonella enterica subsp. enterica serovar Typhimurium LB5010 strain, conferred it to agglutinate yeast cells on both cultures. RT-PCR revealed that the expression of the fimbrial subunit gene fimA, and fimZ, a regulatory gene of fimA, were both increased in the stbC mutant when grown on LB agar; fimW, a repressor gene of fimA, exhibited lower expression. Flagella were observed in the stbC mutant and this phenotype was correlated with the motile phenotype. Microarray data and RT-PCR indicated that the expression of three genes, motA, motB, and cheM, was enhanced in the stbC mutant. The stbC mutant was resistant to several antibiotics, consistent with the finding that expression of yhcQ and ramA was enhanced. A complementation test revealed that transforming a recombinant plasmid possessing the stbC restored the mannose-sensitive agglutination phenotype to the stbC mutant much as that in the parental Salmonella enterica subsp. enterica serovar Typhimurium LB5010 strain, indicating the possibility of an interplay of different fimbrial systems in coordinating their expression.

Broad-range (pan) Salmonella and Salmonella serotype typhi-specific real-time PCR assays: potential tools for the clinical microbiologist.

Science.gov (United States)

Farrell, John J; Doyle, Laura J; Addison, Rachel M; Reller, L Barth; Hall, Geraldine S; Procop, Gary W

2005-03-01

We describe broad-range salmonellae (ie, Salmonella) and Salmonella serotype Typhi-specific LightCycler (Roche Diagnostics, Indianapolis, IN) real-time polymerase chain reaction assays. We validated these with a battery of 280 bacteria, 108 of which were salmonellae representing 20 serotypes. In addition, 298 isolates from 170 clinical specimens that were suspected to possibly represent Salmonella were tested with the pan- Salmonella assay. Finally, the pan-Salmonella assay also was used to test DNA extracts from 101 archived, frozen stool specimens, 55 of which were culture-positive for salmonellae. Both assays were 100% sensitive and specific when cultured isolates of the battery were tested. The pan- Salmonella assay also characterized correctly all salmonellae on the primary isolation agar and was 96% sensitive (53/55) and 96% specific (49/51) when nucleic acid extracts from direct stool specimens were tested. These assays represent potential tools the clinical microbiologist could use to screen suspect isolates or stool specimens for Salmonella.

Construction of physical and genetic maps of Chlamydia trachomatis serovar L2 by pulsed-field gel electrophoresis

DEFF Research Database (Denmark)

Birkelund, Svend; Stephens, RS

1992-01-01

We constructed the physical map of Chlamydia trachomatis serovar L2 by using three restriction endonucleases, NotI (GC[GGCCGC), SgrAI (C(A/G)[CCGG(T/G)G), and Sse8387I (CCTGCA[GG), and we analyzed the fragments by pulsed-field gel electrophoresis. A total of 25 restriction endonuclease sites and 13...... genes and/or operons were located on the map. The genome size was determined to be 1,045 kb. Neither highly transcribed chlamydia genes nor developmental cycle-specific genes were clustered on the genome....

Fiebre Tifoidea Diagnóstico por pruebas inmunoenzimáticas: Elisa

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Miguel Guzmán

1981-06-01

Full Text Available Este trabajo describe el desarrollo y normalización de una técnica inmunoenzimática para el diagnóstico indirecto de la Fiebre Tifoidea. El método permite un análisis simple y objetivo de los resultados. La reacción enzimática es proporcional a la concentración de anticuerpos en el suero contra el antígeno somático-0, por tanto, el método es cuantitativo. Por lo demás, la técnica tiene un alto grado de especificidad para Salmonella typhi, ya que los sueros de pacientes con Salmonelosis causada por Salmonella enteritidis serotipos paratyphi A, B y typhimurium dieron resultados negativos, en forma similar a los presentados por el grupo control antes de la vacunación específica. Los resultados obtenidos con esta técnica permitieron definir el nivel de anticuerpos que puede presentar una población control supuestamente sana frente a los niveles inducidos por la enfermedad. Los resultados postvacunales en el grupo control mostraron títulos sorprendentemente bajos; un análisis de este fenómeno se presentó en forma amplia. Igualmente se proponen futuras investigaciones sobre este campo.

Enteric fever in Mumbai--clinical profile, sensitivity patterns and response to antimicrobials.

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Jog, S; Soman, R; Singhal, T; Rodrigues, C; Mehta, A; Dastur, F D

2008-04-01

Enteric fever is endemic in Mumbai and its diagnosis poses several problems. Our main aim was to study the clinical profile, haematological features of culture proven typhoid cases, the antimicrobial susceptibility pattern of the isolates and the time to defervescence with the treatment received. This was a retospective chart review of all cases of culture proven enteric fever carried out at a tertiary care private hospital in Mumbai over the period January 2003 to September 2005. Culture positivity in our study was 52.6%. Sixty one percent of the isolates were Salmonella typhi while 39% were Salmonella paratyphi A. An absolute eosinopenia was seen in 76.9% of the patients. Before being admitted to the hospital, 46.2% received antibiotics. The mean time to defervescence in patients who received prior antibiotics was 4.5 days while that in those who did not receive prior antibiotics was 5.1 days. A high culture positivity despite prior or ongoing antibiotic treatment was seen. Absolute eosinophil count of 0% could be an important marker of typhoid. High prevalence of nalidixic acid resistance, a marker of resistance to fluoroquinolones was observed. Combination treatment was not found to be superior to treatment with a single antibiotic.

Risk factors associated with Salmonella enterica serovar typhimurium infection in Danish broiler flocks

DEFF Research Database (Denmark)

Skov, M. N.; Angen, Øystein; Chriel, M.

1999-01-01

A retrospective longitudinal study was conducted to identify risk factors associated with Salmonella enterica serovar typhimurium (S. typhimurium) infection in Danish broiler flocks. The data included all broiler flocks slaughtered in 1995, and the epidemiological unit was the individual broiler...... flock. The S. typhimurium status was determined by microbiological examination of 60 fresh fecal samples. This procedure should detect an infected flock with a probability above 95%, if the prevalence is above 5%, and given that the sensitivity of the test is 100%. Nineteen variables were selected...... for analysis. Five factors and an interaction term were found significant by multivariate logistic regression analysis. An increased risk for S, typhimurium infection was associated with two parent flocks, one confirmed infected and one suspected of being infected with S. typhimurium, with two...

Immune Response of Chicken Gut to Natural Colonization by Gut Microflora and to Salmonella enterica Serovar Enteritidis Infection ▿

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Crhanova, Magdalena; Hradecka, Helena; Faldynova, Marcela; Matulova, Marta; Havlickova, Hana; Sisak, Frantisek; Rychlik, Ivan

2011-01-01

In commercial poultry production, there is a lack of natural flora providers since chickens are hatched in the clean environment of a hatchery. Events occurring soon after hatching are therefore of particular importance, and that is why we were interested in the development of the gut microbial community, the immune response to natural microbial colonization, and the response to Salmonella enterica serovar Enteritidis infection as a function of chicken age. The complexity of chicken gut micro...

A naturally occurring single nucleotide polymorphism in the Salmonella SPI-2 type III effector srfH/sseI controls early extraintestinal dissemination.

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Joshua M Thornbrough

Full Text Available CD18 expressing phagocytes associated with the gastro-intestinal (GI epithelium can shuttle Salmonella directly into the bloodstream within a few minutes following microbial ingestion. We have previously demonstrated that Salmonella controls the CD18 pathway to deeper tissue, manipulating the migratory properties of infected cells as an unappreciated component of its pathogenesis. We have observed that one type III effector, SrfH (also called SseI that Salmonella secretes into infected phagocytes manipulates the host protein TRIP6 to stimulate their migration. Paradoxically, SrfH was shown in another study to subvert a different host protein, IQGAP1, in a manner that inhibits the productive motility of such cells, perhaps to avoid interactions with T cells. Here, we resolve the discrepancy. We report that one naturally occurring allele of srfH promotes the migration of infected phagocytes into the bloodstream, while another naturally occurring allele that differs by only a single nucleotide polymorphism (SNP does not. This SNP determines if the protein contains an aspartic acid or a glycine residue at position 103 and may determine if SrfH binds TRIP6. SrfH Gly103 is a rare allele, but is present in the highly invasive strain Salmonella enterica serovar Typhimurium UK-1 (stands for universal killer. It is also present in the genome of the only sequenced strain belonging to the emerging pandemic Salmonella enterica serovar 4, [5],12,i:-, which is frequently associated with septicemia. Finally, we present evidence that suggests that Gifsy-2, the bacteriophage upon which srfH resides, is present in a clinical isolate of the human-specific pathogen, Salmonella enterica serovar Typhi. These observations may have interesting implications for our understanding of Salmonella pathogenesis.

Iron-regulated proteins (IRPS of leptospira biflexa serovar Patoc strain Patoc I

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Sritharan M

2004-01-01

Full Text Available BACKGROUND: Iron deficiency has been shown to induce the expression of siderophores and their receptors, the iron-regulated membrane proteins in a number of bacterial systems. In this study, the response of Leptospira biflexa serovar Patoc strain Patoc I to conditions of iron deprivation was assessed and the expression of siderophores and iron-regulated proteins is reported. MATERIALS AND METHODS: Two methods were used for establishing conditions of iron deprivation. One method consisted of addition of the iron chelators ethylenediamine-N, N′-diacetic acid (EDDA and ethylenediamine di-o-hydroxyphenylacetic acid (EDDHPA and the second method involved the addition of iron at 0.02 µg Fe/mL. Alternatively, iron sufficient conditions were achieved by omitting the chelators in the former method and adding 4 µg Fe/mL of the medium in the latter protocol. Triton X-114 extraction of the cells was done to isolate the proteins in the outer membrane (detergent phase, periplasmic space (aqueous phase and the protoplasmic cylinder (cell pellet. The proteins were subjected to SDS-PAGE for analysis. RESULTS: In the presence of the iron-chelators, four iron-regulated proteins (IRPs of apparent molecular masses of 82, 64, 60 and 33 kDa were expressed. The 82-kDa protein was seen only in the aqueous phase, while the other three proteins were seen in both the aqueous and detergent fractions. These proteins were not identified in organisms grown in the absence of the iron chelators. The 64, 60 and the 33 kDa proteins were also demonstrated in organisms grown in media with 0.02 µg Fe/mL. In addition, a 24 kDa protein was found to be down-regulated at this concentration of iron as compared to the high level of expression in organisms grown with 4 µg Fe/mL. The blue CAS agar plates with top agar containing 0.02µg Fe/mL showed a colour change to orange-red. CONCLUSION: The expression of siderophores and iron-regulated proteins under conditions of iron deprivation

PRODUCTION OF BACTERIOCIN EC2 AND ITS INTERFERENCE IN THE GROWTH OF SALMONELLA TYPHI IN A MILK MATRIX

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Yuri de Jesus Lopes de Abreu

2013-08-01

Full Text Available Bacterial interference can occur through various mechanisms, including the production of peroxides, acids, ammonia, bacteriolytic enzymes or bacteriocins. The strain Escherichia coli EC2 produces the antimicrobial substance (AMS EC2, able to inhibit different strains of Gram-negative bacteria isolated from food, as E. coli and Salmonella sp. The activity of AMS EC2 was lost after treatment with proteolytic enzymes, indicating the presence of an active proteinaceous compound, suggesting that it is a bacteriocin. The substance, renamed bacteriocin EC2, has its better production when the producer strain is grown on Casoy medium, at 37ºC and pH 6.0, without NaCl addition, but it is also able to be produced in milk. When co-cultivated in UHT milk with the producer strain E. coli EC2, the growth of the indicator strain Salmonella Typhi is totally inhibited within the first 4 hours of incubation, suggesting a potential application of bacteriocin EC2 in the control of Salmonella sp. e.g. in foods.

Antimicrobial resistance in Salmonella enterica subsp. enterica serovar typhimurium from humans and production animals

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Seyfarth, Anne Mette; Wegener, Henrik Caspar; FrimodtMoller, N.

1997-01-01

: Poultry strains were usually resistant only to ampicillin, white pig and cattle isolates were most often resistant to sulphonamide, tetracycline and streptomycin. Typing of the strains showed that some animal strains and human strains were indistinguishable. In conclusion, while antimicrobial resistance......We have studied the frequency of antimicrobial resistance and epidemiological relatedness among 473 isolates of Salmonella enterica subsp, enterica serovar typhimurium (S. typhimurium) from human and veterinary sources. The human strains were clinical isolates from patients with diarrhoea sent...... to the State Serum Institute during August 1993 (228 isolates). The animal strains were isolated from clinical or subclinical infections in cattle (48 isolates), pigs (99 isolates) or poultry (98 isolates), all from 1993. All strains were tested against 22 different antimicrobial agents used in both human...

Genomics of an emerging clone of Salmonella serovar Typhimurium ST313 from Nigeria and the Democratic Republic of Congo.

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Leekitcharoenphon, Pimlapas; Friis, Carsten; Zankari, Ea; Svendsen, Christina Aaby; Price, Lance B; Rahmani, Maral; Herrero-Fresno, Ana; Fashae, Kayode; Vandenberg, Olivier; Aarestrup, Frank M; Hendriksen, Rene S

2013-10-15

Salmonella enterica serovar Typhimurium ST313 is an invasive and phylogenetically distinct lineage present in sub-Saharan Africa. We report the presence of S. Typhimurium ST313 from patients in the Democratic Republic of Congo and Nigeria. Eighteen S. Typhimurium ST313 isolates were characterized by antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). Additionally, six of the isolates were characterized by whole genome sequence typing (WGST). The presence of a putative virulence determinant was examined in 177 Salmonella isolates belonging to 57 different serovars. All S. Typhimurium ST313 isolates harbored resistant genes encoded by blaTEM1b, catA1, strA/B, sul1, and dfrA1. Additionally, aac(6')1aa gene was detected. Phylogenetic analyses revealed close genetic relationships among Congolese and Nigerian isolates from both blood and stool. Comparative genomic analyses identified a putative virulence fragment (ST313-TD) unique to S. Typhimurium ST313 and S. Dublin. We showed in a limited number of isolates that S. Typhimurium ST313 is a prevalent sequence-type causing gastrointestinal diseases and septicemia in patients from Nigeria and DRC. We found three distinct phylogenetic clusters based on the origin of isolation suggesting some spatial evolution. Comparative genomics showed an interesting putative virulence fragment (ST313-TD) unique to S. Typhimurium ST313 and invasive S. Dublin.

Production and characterization of monoclonal antibodies to the edta extract of Leptospira interrogans, serovar icterohaemorrhagiae

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Lilian Terezinha de Queiroz Leite

1996-10-01

Full Text Available Monoclonal antibodies (MABs ivere produced against an etbylenediaminetetraacetate (EDTA extract of Leptospira interrogans serovar icterohaemorrhagiae being characterized by gel precipitation as IgM and IgG (IgGl and IgG2b. The EDTA extract was detected as several bands by silver staining in SDS-PAGE. In the Western blot the bands around 20 KDa reacted with a monoclonal antibody, 47B4D6, and was oxidized by periodate and was not digested by pronase, suggesting that the determinant is of carbohydrate nature, lmmunocytochemistry, using colloidal gold labeling, showed that an EDTA extract determinant recognized by monoclonal antibody 47B4D6, is localized under the outer envelope of serovar icterohaemorrhagiae. Hoe AIAB raised against the EDTA extract was not able to protect hamsters from lethal challenge with virulent homologous leptospires.Anticorpos monoclonais (AcM foram produzidos contra o extrato EDTA obtido de Leptospira interrogans, sorovar icterohaemorrhagiae. Pelo teste de precipitação foram caracterizados como IgM e IgG (IgGl e IgG2. A eletroforese em gel de poliacrilamida do extrato EDTA revelou diversas bandas quando corada pela prata. No "Western blot", as bandas em torno de 20 kDa reagiram com o AcM 47B4D6, foram oxidadas pelo periodato e não digeridas pela pronase, sugerindo que o determinante é de natureza carboidrato. O determinante reconhecido pelo AcM 47B4D6 estã localizado sob o envelope externo como revelado pela imunocitoquímica usando marcação com ouro coloidal. O AcM contra extrato EDTA do sorovar icterohaemorrahagiae não protegeu hamsters quando inoculados com lepstopira homóloga virulenta.

The unrecognized burden of typhoid fever.

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Obaro, Stephen K; Iroh Tam, Pui-Ying; Mintz, Eric Daniel

2017-03-01

Typhoid fever (TF), caused by Salmonella enterica serovar Typhi, is the most common cause of enteric fever, responsible for an estimated 129,000 deaths and more than 11 million cases annually. Although several reviews have provided global and regional TF disease burden estimates, major gaps in our understanding of TF epidemiology remain. Areas covered: We provide an overview of the gaps in current estimates of TF disease burden and offer suggestions for addressing them, so that affected communities can receive the full potential of disease prevention offered by vaccination and water, sanitation, and hygiene interventions. Expert commentary: Current disease burden estimates for TF do not capture cases from certain host populations, nor those with atypical presentations of TF, which may lead to substantial underestimation of TF cases and deaths. These knowledge gaps pose major obstacles to the informed use of current and new generation typhoid vaccines.

Receptor binding proteins of Listeria monocytogenes bacteriophages A118 and P35 recognize serovar-specific teichoic acids

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Bielmann, Regula; Habann, Matthias; Eugster, Marcel R. [Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092 Zurich (Switzerland); Lurz, Rudi [Max-Planck Institute for Molecular Genetics, 14195 Berlin (Germany); Calendar, Richard [Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202 (United States); Klumpp, Jochen, E-mail: jochen.klumpp@hest.ethz.ch [Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092 Zurich (Switzerland); Loessner, Martin J. [Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092 Zurich (Switzerland)

2015-03-15

Adsorption of a bacteriophage to the host requires recognition of a cell wall-associated receptor by a receptor binding protein (RBP). This recognition is specific, and high affinity binding is essential for efficient virus attachment. The molecular details of phage adsorption to the Gram-positive cell are poorly understood. We present the first description of receptor binding proteins and a tail tip structure for the siphovirus group infecting Listeria monocytogenes. The host-range determining factors in two phages, A118 and P35 specific for L. monocytogenes serovar 1/2 have been determined. Two proteins were identified as RBPs in phage A118. Rhamnose residues in wall teichoic acids represent the binding ligands for both proteins. In phage P35, protein gp16 could be identified as RBP and the role of both rhamnose and N-acetylglucosamine in phage adsorption was confirmed. Immunogold-labeling and transmission electron microscopy allowed the creation of a topological model of the A118 phage tail. - Highlights: • We present the first description of receptor binding proteins and a tail tip structure for the Siphovirus group infecting Listeria monocytogenes. • The host-range determining factors in two phages, A118 and P35 specific for L. monocytogenes serovar 1/2 have been determined. • Rhamnose residues in wall teichoic acids represent the binding ligands for both receptor binding proteins in phage A118. • Rhamnose and N-acetylglucosamine are required for adsorption of phage P35. • We preset a topological model of the A118 phage tail.

Impact of the choice of reference genome on the ability of the core genome SNV methodology to distinguish strains of Salmonella enterica serovar Heidelberg.

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Usongo, Valentine; Berry, Chrystal; Yousfi, Khadidja; Doualla-Bell, Florence; Labbé, Genevieve; Johnson, Roger; Fournier, Eric; Nadon, Celine; Goodridge, Lawrence; Bekal, Sadjia

2018-01-01

Salmonella enterica serovar Heidelberg (S. Heidelberg) is one of the top serovars causing human salmonellosis. The core genome single nucleotide variant pipeline (cgSNV) is one of several whole genome based sequence typing methods used for the laboratory investigation of foodborne pathogens. SNV detection using this method requires a reference genome. The purpose of this study was to investigate the impact of the choice of the reference genome on the cgSNV-informed phylogenetic clustering and inferred isolate relationships. We found that using a draft or closed genome of S. Heidelberg as reference did not impact the ability of the cgSNV methodology to differentiate among 145 S. Heidelberg isolates involved in foodborne outbreaks. We also found that using a distantly related genome such as S. Dublin as choice of reference led to a loss in resolution since some sporadic isolates were found to cluster together with outbreak isolates. In addition, the genetic distances between outbreak isolates as well as between outbreak and sporadic isolates were overall reduced when S. Dublin was used as the reference genome as opposed to S. Heidelberg.

A Salmonella Typhimurium-Typhi genomic chimera: a model to study Vi polysaccharide capsule function in vivo.

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Angela M Jansen

2011-07-01

Full Text Available The Vi capsular polysaccharide is a virulence-associated factor expressed by Salmonella enterica serotype Typhi but absent from virtually all other Salmonella serotypes. In order to study this determinant in vivo, we characterised a Vi-positive S. Typhimurium (C5.507 Vi(+, harbouring the Salmonella pathogenicity island (SPI-7, which encodes the Vi locus. S. Typhimurium C5.507 Vi(+ colonised and persisted in mice at similar levels compared to the parent strain, S. Typhimurium C5. However, the innate immune response to infection with C5.507 Vi(+ and SGB1, an isogenic derivative not expressing Vi, differed markedly. Infection with C5.507 Vi(+ resulted in a significant reduction in cellular trafficking of innate immune cells, including PMN and NK cells, compared to SGB1 Vi(- infected animals. C5.507 Vi(+ infection stimulated reduced numbers of TNF-α, MIP-2 and perforin producing cells compared to SGB1 Vi(-. The modulating effect associated with Vi was not observed in MyD88(-/- and was reduced in TLR4(-/- mice. The presence of the Vi capsule also correlated with induction of the anti-inflammatory cytokine IL-10 in vivo, a factor that impacted on chemotaxis and the activation of immune cells in vitro.

The Use of a Combined Bioinformatics Approach to Locate Antibiotic Resistance Genes on Plasmids From Whole Genome Sequences of Salmonella enterica Serovars From Humans in Ghana

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Egle Kudirkiene

2018-05-01

Full Text Available In the current study, we identified plasmids carrying antimicrobial resistance genes in draft whole genome sequences of 16 selected Salmonella enterica isolates representing six different serovars from humans in Ghana. The plasmids and the location of resistance genes in the genomes were predicted using a combination of PlasmidFinder, ResFinder, plasmidSPAdes and BLAST genomic analysis tools. Subsequently, S1-PFGE was employed for analysis of plasmid profiles. Whole genome sequencing confirmed the presence of antimicrobial resistance genes in Salmonella isolates showing multidrug resistance phenotypically. ESBL, either blaTEM52−B or blaCTX−M15 were present in two cephalosporin resistant isolates of S. Virchow and S. Poona, respectively. The systematic genome analysis revealed the presence of different plasmids in different serovars, with or without insertion of antimicrobial resistance genes. In S. Enteritidis, resistance genes were carried predominantly on plasmids of IncN type, in S. Typhimurium on plasmids of IncFII(S/IncFIB(S/IncQ1 type. In S. Virchow and in S. Poona, resistance genes were detected on plasmids of IncX1 and TrfA/IncHI2/IncHI2A type, respectively. The latter two plasmids were described for the first time in these serovars. The combination of genomic analytical tools allowed nearly full mapping of the resistance plasmids in all Salmonella strains analyzed. The results suggest that the improved analytical approach used in the current study may be used to identify plasmids that are specifically associated with resistance phenotypes in whole genome sequences. Such knowledge would allow the development of rapid multidrug resistance tracking tools in Salmonella populations using WGS.

Population-based incidence of typhoid fever in an urban informal settlement and a rural area in Kenya: implications for typhoid vaccine use in Africa.

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Robert F Breiman

Full Text Available BACKGROUND: High rates of typhoid fever in children in urban settings in Asia have led to focus on childhood immunization in Asian cities, but not in Africa, where data, mostly from rural areas, have shown low disease incidence. We set out to compare incidence of typhoid fever in a densely populated urban slum and a rural community in Kenya, hypothesizing higher rates in the urban area, given crowding and suboptimal access to safe water, sanitation and hygiene. METHODS: During 2007-9, we conducted population-based surveillance in Kibera, an urban informal settlement in Nairobi, and in Lwak, a rural area in western Kenya. Participants had free access to study clinics; field workers visited their homes biweekly to collect information about acute illnesses. In clinic, blood cultures were processed from patients with fever or pneumonia. Crude and adjusted incidence rates were calculated. RESULTS: In the urban site, the overall crude incidence of Salmonella enterica serovar Typhi (S. Typhi bacteremia was 247 cases per 100,000 person-years of observation (pyo with highest rates in children 5-9 years old (596 per 100,000 pyo and 2-4 years old (521 per 100,000 pyo. Crude overall incidence in Lwak was 29 cases per 100,000 pyo with low rates in children 2-4 and 5-9 years old (28 and 18 cases per 100,000 pyo, respectively. Adjusted incidence rates were highest in 2-4 year old urban children (2,243 per 100,000 pyo which were >15-fold higher than rates in the rural site for the same age group. Nearly 75% of S. Typhi isolates were multi-drug resistant. CONCLUSIONS: This systematic urban slum and rural comparison showed dramatically higher typhoid incidence among urban children <10 years old with rates similar to those from Asian urban slums. The findings have potential policy implications for use of typhoid vaccines in increasingly urban Africa.

Homologous stress adaptation, antibiotic resistance, and biofilm forming ability of Salmonella enterica serovar Heidelberg (ATCC8326) on different food-contact surfaces following exposure to sub-lethal chlorine concentrations

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Salmonella enterica serovar Heidelberg (American Type Culture Collection; ATCC 8326) was examined for the ability to adapt to the homologous stress of chlorine through exposure to increasing chlorine concentrations (25 ppm daily increments) in tryptic soy broth (TSB). The tested strain exhibited an ...

Desarrollo de una técnica de inmunoelectrotransferencia "Westernblot" para la detección de anticuerpos contra componentes proteínicos de Salmonella Typhi

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Miguel Guzmán Urrego

1990-12-01

Full Text Available Desde su desarrollo la lnmunoelectrotransferencia (INMET ha sido una herramienta útil en biología molecular así como también en el diagnóstico de diferentes enfermedades infecciosas. Tradicionalniente la demostración de anticuerpos contra Salmonella typhi, se ha enfocado hacia la detección de aquellos, que se producen contra lipopolisacáridos, especialmente los que se relacionan con el antígeno somático "0". Pero pocos trabajos, se han realizado para la detección de anticuerpos contra otros antígenos tales como proteínas protoplasmáticas. Este trabajo intenta demostrar si tales anticuerpos se producen en conejos inmunizados experimentalmente, así como también en voluntarios vacunados contra la fiebre Tifoidea con lavacuna oral (cepa Ty21a. El antígeno preparado y purificado a partir de una cepa de Salmonella typhi, fue suspendido en una solución tampón y sonicado para obtener sus productos celulares; de esta manera y con la adecuada concentración de proteínas fue separado en gel de poliacrilamida en sus diferentes fracciones antigénicas y luego transferidos a membranas de nitrocelulosa en donde por medio de reacción inmunoenzimática, se visualizó la banda característica, al poner en contacto la membrana con el antisuero hiperinmune obtenido en conejos (Modelo Experimental y el suero de voluntarios antes y después de la inmunización (Modelo  Humano. La banda visualizada correspondió a un peso aproximado de 38.000 kd. Trece de los voluntarios (32.5%, presentaron esta misma banda antes de la inmunización, la cual, aunque más tenue, representó un complejo antígeno-anticuerpo, lo cual, induce a pensar en un posible contacto con el microorganismo en el pasado. La posibilidad de la reacción cruzada se descartó realizando el mismo procedimiento con lisados de Escherichia coli.

Respiratory hydrogen use by Salmonella enterica serovar Typhimurium is essential for virulence.

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Maier, R J; Olczak, A; Maier, S; Soni, S; Gunn, J

2004-11-01

Based on available annotated gene sequence information, the enteric pathogen salmonella, like other enteric bacteria, contains three putative membrane-associated H2-using hydrogenase enzymes. These enzymes split molecular H2, releasing low-potential electrons that are used to reduce quinone or heme-containing components of the respiratory chain. Here we show that each of the three distinct membrane-associated hydrogenases of Salmonella enterica serovar Typhimurium is coupled to a respiratory pathway that uses oxygen as the terminal electron acceptor. Cells grown in a blood-based medium expressed four times the amount of hydrogenase (H2 oxidation) activity that cells grown on Luria Bertani medium did. Cells suspended in phosphate-buffered saline consumed 2 mol of H2 per mol of O2 used in the H2-O2 respiratory pathway, and the activity was inhibited by the respiration inhibitor cyanide. Molecular hydrogen levels averaging over 40 microM were measured in organs (i.e., livers and spleens) of live mice, and levels within the intestinal tract (the presumed origin of the gas) were four times greater than this. The half-saturation affinity of S. enterica serovar Typhimurium for H2 is only 2.1 microM, so it is expected that H2-utilizing hydrogenase enzymes are saturated with the reducing substrate in vivo. All three hydrogenase enzymes contribute to the virulence of the bacterium in a typhoid fever-mouse model, based on results from strains with mutations in each of the three hydrogenase genes. The introduced mutations are nonpolar, and growth of the mutant strains was like that of the parent strain. The combined removal of all three hydrogenases resulted in a strain that is avirulent and (in contrast to the parent strain) one that is unable to invade liver or spleen tissue. The introduction of one of the hydrogenase genes into the triple mutant strain on a low-copy-number plasmid resulted in a strain that was able to both oxidize H2 and cause morbidity in mice within 11

Salmonella enterica serovar Enteritidis brain abscess mimicking meningitis after surgery for glioblastoma multiforme: a case report and review of the literature

OpenAIRE

Luciani, L?a; Dubourg, Gr?gory; Graillon, Thomas; Honnorat, Estelle; Lepidi, Hubert; Drancourt, Michel; Seng, Piseth; Stein, Andreas

2016-01-01

Background Salmonella brain abscess associated with brain tumor is rare. Only 11 cases have been reported to date. Here we report a case of brain abscess caused by Salmonella enterica serovar Enteritidis mimicking post-surgical meningitis in a patient with glioblastoma multiforme. Case presentation A 60-year-old Algerian woman was admitted through an emergency department for a 4-day history of headache, nausea and vomiting, and behavioral disorders. Surgery for cerebral tumor excision was per...

Emerging Infectious Disease Implications of Invasive Mammalian Species: The Greater White-Toothed Shrew (Crocidura russula) Is Associated With a Novel Serovar of Pathogenic Leptospira in Ireland.

Science.gov (United States)

Nally, Jarlath E; Arent, Zbigniew; Bayles, Darrell O; Hornsby, Richard L; Gilmore, Colm; Regan, Siobhan; McDevitt, Allan D; Yearsley, Jon; Fanning, Séamus; McMahon, Barry J

2016-12-01

The greater white-toothed shrew (Crocidura russula) is an invasive mammalian species that was first recorded in Ireland in 2007. It currently occupies an area of approximately 7,600 km2 on the island. C. russula is normally distributed in Northern Africa and Western Europe, and was previously absent from the British Isles. Whilst invasive species can have dramatic and rapid impacts on faunal and floral communities, they may also be carriers of pathogens facilitating disease transmission in potentially naive populations. Pathogenic leptospires are endemic in Ireland and a significant cause of human and animal disease. From 18 trapped C. russula, 3 isolates of Leptospira were cultured. However, typing of these isolates by standard serological reference methods was negative, and suggested an, as yet, unidentified serovar. Sequence analysis of 16S ribosomal RNA and secY indicated that these novel isolates belong to Leptospira alstonii, a unique pathogenic species of which only 7 isolates have been described to date. Earlier isolations were limited geographically to China, Japan and Malaysia, and this leptospiral species had not previously been cultured from mammals. Restriction enzyme analysis (REA) further confirms the novelty of these strains since no similar patterns were observed with a reference database of leptospires. As with other pathogenic Leptospira species, these isolates contain lipL32 and do not grow in the presence of 8-azagunaine; however no evidence of disease was apparent after experimental infection of hamsters. These isolates are genetically related to L. alstonii but have a novel REA pattern; they represent a new serovar which we designate as serovar Room22. This study demonstrates that invasive mammalian species act as bridge vectors of novel zoonotic pathogens such as Leptospira.

The plasmid-encoded Ipf and Klf fimbriae display different expression and varying roles in the virulence of Salmonella enterica serovar Infantis in mouse vs. avian hosts.

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Gili Aviv

2017-08-01

Full Text Available Salmonella enterica serovar Infantis is one of the prevalent Salmonella serovars worldwide. Different emergent clones of S. Infantis were shown to acquire the pESI virulence-resistance megaplasmid affecting its ecology and pathogenicity. Here, we studied two previously uncharacterized pESI-encoded chaperone-usher fimbriae, named Ipf and Klf. While Ipf homologs are rare and were found only in S. enterica subspecies diarizonae and subspecies VII, Klf is related to the known K88-Fae fimbria and klf clusters were identified in seven S. enterica subspecies I serovars, harboring interchanging alleles of the fimbria major subunit, KlfG. Regulation studies showed that the klf genes expression is negatively and positively controlled by the pESI-encoded regulators KlfL and KlfB, respectively, and are activated by the ancestral leucine-responsive regulator (Lrp. ipf genes are negatively regulated by Fur and activated by OmpR. Furthermore, induced expression of both klf and ipf clusters occurs under microaerobic conditions and at 41°C compared to 37°C, in-vitro. Consistent with these results, we demonstrate higher expression of ipf and klf in chicks compared to mice, characterized by physiological temperature of 41.2°C and 37°C, respectively. Interestingly, while Klf was dispensable for S. Infantis colonization in the mouse, Ipf was required for maximal colonization in the murine ileum. In contrast to these phenotypes in mice, both Klf and Ipf contributed to a restrained infection in chicks, where the absence of these fimbriae has led to moderately higher bacterial burden in the avian host. Taken together, these data suggest that physiological differences between host species, such as the body temperature, can confer differences in fimbriome expression, affecting Salmonella colonization and other host-pathogen interplays.

Ureaplasma parvum serovar 3 multiple banded antigen size variation after chronic intra-amniotic infection/colonization.

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Robinson, James W; Dando, Samantha J; Nitsos, Ilias; Newnham, John; Polglase, Graeme R; Kallapur, Suhas G; Pillow, J Jane; Kramer, Boris W; Jobe, Alan H; Payton, Diane; Knox, Christine L

2013-01-01

Ureaplasma species are the microorganisms most frequently associated with adverse pregnancy outcomes. The multiple banded antigen (MBA), a surface-exposed lipoprotein, is a key virulence factor of ureaplasmas. The MBA demonstrates size variation, which we have shown previously to be correlated with the severity of chorioamnion inflammation. We aimed to investigate U. parvum serovar 3 pathogenesis in vivo, using a sheep model, by investigating: MBA variation after long term (chronic) and short term (acute) durations of in utero ureaplasma infections, and the severity of chorioamnionitis and inflammation in other fetal tissues. Inocula of 2 × 10(7) colony-forming-units (CFU) of U. parvum serovar 3 (Up) or media controls (C) were injected intra-amniotically into pregnant ewes at one of three time points: day 55 (69d Up, n = 8; C69, n = 4); day 117 (7d Up, n = 8; C7, n = 2); and day 121 (3d Up, n = 8; C3, n = 2) of gestation (term = 145-150d). At day 124, preterm fetuses were delivered surgically. Samples of chorioamnion, fetal lung, and umbilical cord were: (i) snap frozen for subsequent ureaplasma culture, and (ii) fixed, embedded, sectioned and stained by haematoxylin and eosin stain for histological analysis. Selected fetal lung clinical ureaplasma isolates were cloned and filtered to obtain cultures from a single CFU. Passage 1 and clone 2 ureaplasma cultures were tested by western blot to demonstrate MBA variation. In acute durations of ureaplasma infection no MBA variants (3d Up) or very few MBA variants (7d Up) were present when compared to the original inoculum. However, numerous MBA size variants were generated in vivo (alike within contiguous tissues, amniotic fluid and fetal lung, but different variants were present within chorioamnion), during chronic, 69d exposure to ureaplasma infection. For the first time we have shown that the degree of ureaplasma MBA variation in vivo increased with the duration of gestation.

Ureaplasma parvum serovar 3 multiple banded antigen size variation after chronic intra-amniotic infection/colonization.

Directory of Open Access Journals (Sweden)

James W Robinson

Full Text Available Ureaplasma species are the microorganisms most frequently associated with adverse pregnancy outcomes. The multiple banded antigen (MBA, a surface-exposed lipoprotein, is a key virulence factor of ureaplasmas. The MBA demonstrates size variation, which we have shown previously to be correlated with the severity of chorioamnion inflammation. We aimed to investigate U. parvum serovar 3 pathogenesis in vivo, using a sheep model, by investigating: MBA variation after long term (chronic and short term (acute durations of in utero ureaplasma infections, and the severity of chorioamnionitis and inflammation in other fetal tissues. Inocula of 2 × 10(7 colony-forming-units (CFU of U. parvum serovar 3 (Up or media controls (C were injected intra-amniotically into pregnant ewes at one of three time points: day 55 (69d Up, n = 8; C69, n = 4; day 117 (7d Up, n = 8; C7, n = 2; and day 121 (3d Up, n = 8; C3, n = 2 of gestation (term = 145-150d. At day 124, preterm fetuses were delivered surgically. Samples of chorioamnion, fetal lung, and umbilical cord were: (i snap frozen for subsequent ureaplasma culture, and (ii fixed, embedded, sectioned and stained by haematoxylin and eosin stain for histological analysis. Selected fetal lung clinical ureaplasma isolates were cloned and filtered to obtain cultures from a single CFU. Passage 1 and clone 2 ureaplasma cultures were tested by western blot to demonstrate MBA variation. In acute durations of ureaplasma infection no MBA variants (3d Up or very few MBA variants (7d Up were present when compared to the original inoculum. However, numerous MBA size variants were generated in vivo (alike within contiguous tissues, amniotic fluid and fetal lung, but different variants were present within chorioamnion, during chronic, 69d exposure to ureaplasma infection. For the first time we have shown that the degree of ureaplasma MBA variation in vivo increased with the duration of gestation.

ANTIBACTERIAL EFFECT OF GARLIC (ALLIUM SATIVUM AND GINGER (ZINGIBER OFFICINALE AGAINST STAPHYLOCOCCUS AUREUS, SALMONELLA TYPHI, ESCHERICHIA COLI AND BACILLUS CEREUS

Directory of Open Access Journals (Sweden)

Bandna Chand

2013-02-01

Full Text Available Antibacterial activity of extracts of Allium sativum (garlic and Zingiber officinale (ginger has been evaluated against four different bacteria namely Escherichia coli, Salmonella Typhi, Staphylococcus aureus and Bacillus cereus. Two methods were used to determine the antimicrobial activity of garlic and ginger extracts namely disk diffusion method and agar well diffusion method. Garlic extract exhibited excellent antibacterial activity against all four test organisms while ginger extract showed antibacterial activity against Bacillus cereus and Staphylococcus aureus only. In addition, agar well diffusion method showed higher zone in inhibition when compared with the zone of inhibition produced by the spice of same concentration against the test microorganism by disk diffusion method. Antibiotic sensitivity of the four different bacteria was tested with commercially available antibiotics namely Ciprofloxacin; Oxytetracycline; Vancomycin; Streptomycin; Gentamicin; Tetracycline; Novobiocin; Amikacin and Penicillin G. Penicillin G produced the highest zone of inhibition of 40.00±0.00against Staphylococcus aureus and the lowest zone of inhibition of 0.00±0.00against Escherichia coli.

TolC is important for bacterial survival and oxidative stress response in Salmonella enterica serovar Choleraesuis in an acidic environment.

Science.gov (United States)

Lee, Jen-Jie; Wu, Ying-Chen; Kuo, Chih-Jung; Hsuan, Shih-Ling; Chen, Ter-Hsin

2016-09-25

The outer membrane protein TolC, which is one of the key components of several multidrug efflux pumps, is thought to be involved in various independent systems in Enterobacteriaceae. Since the acidic environment of the stomach is an important protection barrier against foodborne pathogen infections in hosts, we evaluated whether TolC played a role in the acid tolerance of Salmonella enterica serovar Choleraesuis. Comparison of the acid tolerance of the tolC mutant and the parental wild-type strain showed that the absence of TolC limits the ability of Salmonella to sustain life under extreme acidic conditions. Additionally, the mutant exhibited morphological changes during growth in an acidic medium, leading to the conflicting results of cell viability measured by spectrophotometry and colony-forming unit counting. Reverse-transcriptional-PCR analysis indicated that acid-related molecules, apparatus, or enzymes and oxidation-induced factors were significantly affected by the acidic environment in the null-tolC mutant. The elongated cellular morphology was restored by adding antioxidants to the culture medium. Furthermore, we found that increased cellular antioxidative activity provides an overlapping protection against acid killing, demonstrating the complexity of the bacterial acid stress response. Our findings reinforce the multifunctional characteristics of TolC in acid tolerance or oxidative stress resistance and support the correlative protection mechanism between oxygen- and acid-mediated stress responses in Salmonella enterica serovar Choleraesuis. Copyright © 2016 Elsevier B.V. All rights reserved.

Multidrug-resistant typhoid fever with neurologic findings on the Malawi-Mozambique border.

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Lutterloh, Emily; Likaka, Andrew; Sejvar, James; Manda, Robert; Naiene, Jeremias; Monroe, Stephan S; Khaila, Tadala; Chilima, Benson; Mallewa, Macpherson; Kampondeni, Sam D; Lowther, Sara A; Capewell, Linda; Date, Kashmira; Townes, David; Redwood, Yanique; Schier, Joshua G; Nygren, Benjamin; Tippett Barr, Beth; Demby, Austin; Phiri, Abel; Lungu, Rudia; Kaphiyo, James; Humphrys, Michael; Talkington, Deborah; Joyce, Kevin; Stockman, Lauren J; Armstrong, Gregory L; Mintz, Eric

2012-04-01

Salmonella enterica serovar Typhi causes an estimated 22 million cases of typhoid fever and 216 000 deaths annually worldwide. We investigated an outbreak of unexplained febrile illnesses with neurologic findings, determined to be typhoid fever, along the Malawi-Mozambique border. The investigation included active surveillance, interviews, examinations of ill and convalescent persons, medical chart reviews, and laboratory testing. Classification as a suspected case required fever and ≥1 other finding (eg, headache or abdominal pain); a probable case required fever and a positive rapid immunoglobulin M antibody test for typhoid (TUBEX TF); a confirmed case required isolation of Salmonella Typhi from blood or stool. Isolates underwent antimicrobial susceptibility testing and subtyping by pulsed-field gel electrophoresis (PFGE). We identified 303 cases from 18 villages with onset during March-November 2009; 214 were suspected, 43 were probable, and 46 were confirmed cases. Forty patients presented with focal neurologic abnormalities, including a constellation of upper motor neuron signs (n = 19), ataxia (n = 22), and parkinsonism (n = 8). Eleven patients died. All 42 isolates tested were resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole; 4 were also resistant to nalidixic acid. Thirty-five of 42 isolates were indistinguishable by PFGE. The unusual neurologic manifestations posed a diagnostic challenge that was resolved through rapid typhoid antibody testing in the field and subsequent blood culture confirmation in the Malawi national reference laboratory. Extending laboratory diagnostic capacity, including blood culture, to populations at risk for typhoid fever in Africa will improve outbreak detection, response, and clinical treatment.

Expression of intra- and extracellular granzymes in patients with typhoid fever.

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de Jong, Hanna K; Garcia-Laorden, Maria Isabel; Hoogendijk, Arie J; Parry, Christopher M; Maude, Rapeephan R; Dondorp, Arjen M; Faiz, Mohammed Abul; van der Poll, Tom; Wiersinga, Willem Joost

2017-07-01

Typhoid fever, caused by the intracellular pathogen Salmonella (S.) enterica serovar Typhi, remains a major cause of morbidity and mortality worldwide. Granzymes are serine proteases promoting cytotoxic lymphocytes mediated eradication of intracellular pathogens via the induction of cell death and which can also play a role in inflammation. We aimed to characterize the expression of extracellular and intracellular granzymes in patients with typhoid fever and whether the extracellular levels of granzyme correlated with IFN-γ release. We analyzed soluble protein levels of extracellular granzyme A and B in healthy volunteers and patients with confirmed S. Typhi infection on admission and day of discharge, and investigated whether this correlated with interferon (IFN)-γ release, a cytokine significantly expressed in typhoid fever. The intracellular expression of granzyme A, B and K in subsets of lymphocytic cells was determined using flow cytometry. Patients demonstrated a marked increase of extracellular granzyme A and B in acute phase plasma and a correlation of both granzymes with IFN-γ release. In patients, lower plasma levels of granzyme B, but not granzyme A, were found at day of discharge compared to admission, indicating an association of granzyme B with stage of disease. Peripheral blood mononuclear cells of typhoid fever patients had a higher percentage of lymphocytic cells expressing intracellular granzyme A and granzyme B, but not granzyme K, compared to controls. The marked increase observed in extra- and intracellular levels of granzyme expression in patients with typhoid fever, and the correlation with stage of disease, suggests a role for granzymes in the host response to this disease.

Survival and transmission of Salmonella enterica serovar typhimurium in an outdoor organic pig farming environment

DEFF Research Database (Denmark)

Jensen, Annette Nygaard; Dalsgaard, Anders; Stockmarr, Anders

2006-01-01

It was investigated how organic rearing conditions influence the Salmonella enterica infection dynamics in pigs and whether Salmonella persists in the paddock environment. Pigs inoculated with S. enterica serovar Typhimurium were grouped with Salmonella-negative tracer pigs. Bacteriological...... the seroprevalence. Salmonella persisted in the paddock environment, as Salmonella was isolated from 46% of soil and water samples (n = 294). After removal of pigs, Salmonella was found in soil samples for up to. 5 weeks and in shelter huts during the entire test period (7 weeks). Subsequent introduction...... of Salmonella-negative pigs into four naturally Salmonella-contaminated paddocks caused Salmonella infections of pigs in two paddocks. In one of these paddocks, all tracer pigs (n = 10) became infected, coinciding with a previous high Salmonella infection rate and high Salmonella excretion level. Our results...

Diversity of pulsed-field gel electrophoresis pulsotypes, serovars, and antibiotic resistance among Salmonella isolates from wild amphibians and reptiles in the California Central Coast.

Science.gov (United States)

Gorski, Lisa; Jay-Russell, Michele T; Liang, Anita S; Walker, Samarpita; Bengson, Yingjia; Govoni, Jessica; Mandrell, Robert E

2013-06-01

A survey of cold-blooded vertebrates and associated surface waters in a produce-growing region on the Central California Coast was done between May and September 2011 to determine the diversity of Salmonella. Samples from 460 amphibians and reptiles and 119 water samples were collected and cultured for Salmonella. Animals sampled were frogs (n=331), lizards (n=59), newts (n=5), salamanders (n=6), snakes (n=39), and toads (n=20). Salmonella was isolated from 37 individual animals, including frogs, lizards, snakes, and toads. Snakes were the most likely to contain Salmonella, with 59% testing positive followed by 15.3% of lizards, 5% of toads, and 1.2% of frogs. Fifteen water samples (12.6%) were positive. Twenty-two different serovars were identified, and the majority of isolates were S. enterica subsp. IIIb, with subsp. I, II, and IIIa also found. The serovar isolated most frequently was S. enterica subsp. IIIb 16:z₁₀:e,n,x,z₁₅, from snakes and frogs in five different locations. S. enterica subsp. I serovar Typhimurium and the monophasic I 6,8:d:- were isolated from water, and subspecies I Duisburg and its variants were found in animals and water. Some samples contained more than one type of Salmonella. Analysis of pulsed-field gel electrophoresis pulsotypes indicated that some strains persisted in animals and water collected from the same location. Sixty-six isolates displayed antibiotic resistance, with 27 isolates resistant to more than one antibiotic, including a subspecies IIIb isolate from snake having resistance to five different antibiotics. Twenty-three isolates were resistant to more than one class of antibiotic, and six isolates were resistant to three classes. While these subspecies of IIIa and IIIb cause fewer instances of human illness, they may serve as reservoirs of antibiotic resistance, determinants in the environment, and be sources of contamination of leafy greens associated with product recalls.