An isolate of Haemophilus haemolyticus produces a bacteriocin-like substance that inhibits the growth of nontypeable Haemophilus influenzae.

Science.gov (United States)

Latham, Roger D; Gell, David A; Fairbairn, Rory L; Lyons, A Bruce; Shukla, Shakti D; Cho, Kum Yin; Jones, David A; Harkness, Nick M; Tristram, Stephen G

2017-04-01

Nontypeable Haemophilus influenzae (NTHi) frequently colonises the upper respiratory tract and is an important cause of respiratory infections. Resistance to antibiotics is an emerging trend in NTHi and alternative prevention or treatment strategies are required. Haemophilus haemolyticus is a common commensal occupying the same niche as NTHi and, if able to produce substances that inhibit NTHi growth, may have a role as a probiotic. In this study, ammonium sulphate extracts from broth culture of 100 H. haemolyticus isolates were tested for the presence of substances inhibitory to NTHi using a well diffusion assay. One isolate produced a substance that consistently inhibited the growth of NTHi. The substance was inactivated by protease enzymes and had a molecular size of ca. 30 kDa as determined by size exclusion chromatography. When the substance was tested against bacteria from eight Gram-negative and three Gram-positive genera, only Haemophilus spp. were inhibited. Quantitative PCR testing showed the substance to be different to 'haemocin', the previously described bacteriocin of H. influenzae type b. These molecular characteristics, together with narrow-spectrum activity, suggest the substance may be a novel bacteriocin, and there is potential for this H. haemolyticus isolate to function as a probiotic for reduction of colonisation and subsequent infection with NTHi. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

NNDSS - Table II. Giardiasis to Haemophilus influenza

Data.gov (United States)

U.S. Department of Health & Human Services — NNDSS - Table II. Giardiasis to Haemophilus influenza - 2014. In this Table, all conditions with a 5-year average annual national total of more than or equals 1,000...

Invasive Disease Caused by Nontypeable Haemophilus Influenzae

Centers for Disease Control (CDC) Podcasts

2015-11-12

Dr. Elizabeth Briere discusses Nontypeable Haemophilus influenzae which causes a variety of infections in children and adults.  Created: 11/12/2015 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/17/2015.

Haemophilus influenzae Type a Meningitis in Immunocompetent Child, Oman, 2015.

Science.gov (United States)

Sawardekar, Kiran P

2017-07-01

Meningitis caused by Haemophilus influenzae type b (Hib) was eliminated in Oman after the introduction of Hib vaccine in 2001. However, a case of H. influenzae type a meningitis was diagnosed in a child from Oman in 2015, which highlights the need to monitor the incidence of invasive non-Hib H. influenzae disease.

Clinical and microbiological features of Haemophilus influenzae vulvovaginitis in young girls

Science.gov (United States)

Cox, R A; Slack, M P E

2002-01-01

Aims: To define the clinical and microbiological features of vulvovaginitis in prepubertal girls whose genital swabs yielded Haemophilus influenzae. Methods: Laboratory based study and retrospective collection of clinical data from the requesting doctors. Results: Thirty eight isolates of non-capsulate Haemophilus influenzae and one of H parainfluenzae were isolated from 32 girls aged 18 months to 11 years. No other pathogens, such as β haemolytic streptococci or yeasts, were present with H influenzae. The most common biotype was biotype II, comprising 57% of the 26 isolates biotyped. Six children had more than one episode of vulvovaginitis caused by H influenzae and a total of 14 children had recurrent vaginal symptoms. Conclusion: Children who have H influenzae vulvovaginitis are at risk of recurrent symptoms. Biotype II is the one most commonly associated with this condition. PMID:12461068

In vitro selection of resistance in haemophilus influenzae by 4 quinolones and 5 beta-lactams.

Science.gov (United States)

Clark, Catherine; Kosowska, Klaudia; Bozdogan, Bülent; Credito, Kim; Dewasse, Bonifacio; McGhee, Pamela; Jacobs, Michael R; Appelbaum, Peter C

2004-05-01

We tested abilities of ciprofloxacin, levofloxacin, gatifloxacin, moxifloxacin, amoxicillin, amoxicillin/clavulanate, cefixime, cefpodoxime, and cefdinir to select resistant mutants in 5 beta-lactamase positive and 5 beta-lactamase negative Haemophilus influenzae strains by single and multistep methodology. In multistep tests, amoxicillin, amoxicillin/clavulanate and cefpodoxime exposure did not cause >4-fold minimum inhibitory concentration (MIC) increase after 50 days. One mutant selected by cefdinir had one amino acid substitution (Gly490Glu) in PBP3 and became resistant to cefdinir. Cefixime exposure caused 8-fold MIC-increase in 1 strain with TEM but the mutant remained cefixime susceptible and had no alteration in PBP3 or TEM. Among 10 strains tested, ciprofloxacin, moxifloxacin, gatifloxacin, levofloxacin caused >4-fold MIC increase in 6, 6, 5, and 2 strain, respectively. Despite the increases in quinolone MICs, none of the mutants became resistant to quinolones by established criteria. Quinolone selected mutants had quindone resistance-determining region (QRDR) alterations in GyrA, GyrB, ParC, ParE. Four quinolone mutants had no QRDR alterations. Among beta-lactams cefdinir and cefixime selected one mutant each with higher MICs however amoxicillin, amoxicillin/clavulanate, and cefpodoxime exposure did not select resistant mutants.

Vaccine-Induced Waning of Haemophilus influenzae Empyema and Meningitis, Angola

Science.gov (United States)

Peltola, Heikki; Bernardino, Luis; Monteiro, Lurdes; Silvestre, Silvia da Conceição; Anjos, Elizabete; Cruzeiro, Manuel Leite; Pitkäranta, Anne; Roine, Irmeli

2014-01-01

In Angola during 2003–2012, we detected Haemophilus influenzae in 18% of 2,634 and 26% of 2,996 bacteriologically positive pleural or cerebrospinal fluid samples, respectively, from children. After vaccination launch in 2006, H. influenzae empyema declined by 83% and meningitis by 86%. Severe H. influenzae pneumonia and meningitis are preventable by vaccination. PMID:25340259

The role of cytomegalovirus, Haemophilus influenzae and Epstein Barr virus in Guillain Barre syndrome.

Directory of Open Access Journals (Sweden)

Shahriar Nafissi

2013-06-01

Full Text Available Guillain Barre Syndrome (GBS is an inflammatory, usually demyelinating, polyneuropathy; clinically characterized by acute onset of symmetric progressive muscle weakness with loss of myotatic reflexes. Thirty five patients with GBS, defined clinically according to the criteria of Asbury and Cornblath, were recruited from three hospital affiliated to Tehran University of Medical Sciences.As a control group 35 age and sex matched patients with other neurological diseases admitted to the same hospital at the same time, were included in our study. Serum samples were collected before treatment from each patient (within 4 weeks after the disease onset and controls, and stored frozen at -80ºC until serologic assays were done. Serologic testing of pretreatment serum was performed in all patients. Positive titer of virus specific IgM antibody against cytomegalovirus (CMV was found in 6 cases and 2 controls. 34 patients and 31 controls had high titer of anti Haemophilus influenzae IgG and one patient had serologic evidence of a recent Epstein Barr virus (EBV infection. The mean titer of IgG antibody against Haemophilus influenzae in cases and controls was 5.21 and 2.97 respectively. Although serologic evidence of all these infections were more frequent in cases than in controls, only Haemophilus influenzae infection appeared to be significantly related to GBS (P=0.002. Eleven cases and 3 controls had high titers of IgG antibody against Haemophilus influenzae type B (titer >8. There is significant association between high titer of IgG antibody against Haemophilus influenzae and GBS (P=0.017. Our results provide further evidence that Haemophilus influenzae and probably CMV, can be associated with GBS.

Haemophilus influenzae type b pneumonia in Egyptian children ...

African Journals Online (AJOL)

Haemophilus influenzae (Hi) causes more than 3 million cases of serious disease, mainly meningitis and ... One hundred patients with community-acquired pneumonia were investigated for Hib by both real-time PCR and bacterial culture.

Quorum signaling and sensing by nontypeable Haemophilus influenzae

Directory of Open Access Journals (Sweden)

W Edward Swords

2012-07-01

Full Text Available Quorum signals are diffusible factors produced by bacteria that coordinate communal responses. For Haemophilus influenzae, a series of recent papers indicate that production and sensing of quorum signals are determinants of biofilm formation/maturation and persistence in vivo. In this mini-review I will summarize the current knowledge about quorum signaling/sensing by H. influenzae, and identify specific topics for additional study.

[Two cases of invasive Haemophilus influenzae type f infection

DEFF Research Database (Denmark)

Nielsen, J.D.; Lind, J.W.; Bruun, B.

2009-01-01

Two cases of invasive Haemophilus influenzae type f infection are presented: a three-week-old boy with meningitis and a 62-year-old woman with arthritis and bacteremia. Since 1993 vaccination against H. influenzae type b (Hib) has been offered to Danish children. The result has been a remarkable...... decrease in invasive Hib disease. However, physicians need to be aware of the existence of non-type b invasive H. influenzae disease Udgivelsesdato: 2009/1/19...

Plasmid containing a DNA ligase gene from Haemophilus influenzae

International Nuclear Information System (INIS)

McCarthy, D.; Griffin, K.; Setlow, J.K.

1984-01-01

A ligase gene from Haemophilus influenzae was cloned into the shuttle vector pDM2. Although the plasmid did not affect X-ray sensitivity, it caused an increase in UV sensitivity of the wild-type but not excision-defective H. influenzae and a decrease in UV sensitivity of the rec-1 mutant. 14 references, 2 figures

Haemophilus influenzae type f meningitis in a previously healthy boy

DEFF Research Database (Denmark)

Ronit, Andreas; Berg, Ronan M G; Bruunsgaard, Helle

2013-01-01

Non-serotype b strains of Haemophilus influenzae are extremely rare causes of acute bacterial meningitis in immunocompetent individuals. We report a case of acute bacterial meningitis in a 14-year-old boy, who was previously healthy and had been immunised against H influenzae serotype b (Hib...

Oropharyngeal colonization by Haemophilus influenzae in healthy children from Taubaté (São Paulo, prior to the Haemophilus influenzae type b vaccination program in Brazil Colonização da orofaringe de crianças saudáveis de Taubaté (São Paulo por Haemophilus influenzae, antes da introdução da vacina contra Haemophilus influenzae do tipo b no Brasil

Directory of Open Access Journals (Sweden)

Lucia Ferro Bricks

2004-01-01

Full Text Available Haemophilus influenzae is one of the most important bacterial agents of otitis and sinusitis. H. influenzae type b (Hib is one of the main causes of meningitis, pneumonia, and septicemia in nonvaccinated children under 6 years of age. The aims of this study were to determine the prevalence of H. influenzae and Hib oropharyngeal colonization prior to the onset of the Hib vaccination program in Brazil in previously healthy children and to assess the susceptibility profile of this microorganism to a selected group of antimicrobials that are used to treat acute respiratory infections. METHOD: Cultures of Haemophilus influenzae were made from oropharynx swabs from 987 children under 6 years of age who were enrolled in 29 day-care centers in Taubaté (a city of São Paulo state, Brazil between July and December 1998. RESULTS: The prevalence of H. influenzae carriers was 17.4%, and only 5.5% of the strains were beta-lactamase producers. The prevalence of Hib carriers was high, 7.3% on average (range, 0.0 - 33.3%. CONCLUSIONS: The low prevalence of colonization by penicillin-resistant strains indicates that it is not necessary to substitute ampicilin or amoxicilin to effectively treat otitis and sinusitis caused by H. influenzae in Taubaté.Haemophilus influenzae é um dos mais importantes agentes bacterianos de otites e sinusites. Em crianças menores de seis anos de idade não vacinadas contra o H. influenzae do tipo b (Hib, essa bactéria é uma das principais causadoras de meningite, pneumonia e sepse. O objetivo deste estudo foi determinar a prevalência da colonização da orofaringe de crianças previamente saudáveis por H. influenzae e Hib e avaliar o perfil de suscetibilidade desses microorganismos a um grupo seleto de antimicrobianos, que habitualmente são utilizados para tratar as infecções respiratórias agudas. MÉTODO: Foram colhidos swabs da orofaringe de 987 crianças menores de seis anos de idade que freqüentavam 29 creches da

Antimicrobial resistance in Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and group A beta-haemolytic streptococci in 2002-2003. Results of the multinational GRASP Surveillance Program

DEFF Research Database (Denmark)

Beekmann, Susan E; Heilmann, Kris P; Richter, Sandra S

2005-01-01

A multinational surveillance study, GRASP, was conducted between November 2002 and April 2003 with the aim of assessing rates of antimicrobial resistance among 2656 isolates of Streptococcus pneumoniae, 2486 isolates of group A beta-haemolytic streptococci, 1358 isolates of Haemophilus influenzae...... and 1047 of Moraxella catarrhalis from 20 countries in Europe, eastern Asia and southern Africa. Conspicuous differences between various countries were noted in the S. pneumoniae resistance rates observed for penicillin (0-79.2%) and erythromycin (4-66%), along with other antimicrobials. The percentage...... of MDR strains was above 25% in 8 of the 20 countries studied. Group A streptococcal macrolide resistance rates ranged from 0% to 35% by country, while rates of beta-lactamase production ranged from 0% to 39% for H. influenzae and 80-100% for M. catarrhalis. Antibiotic resistance in S. pneumoniae remains...

Methodology optimization and diversification for the investigation of virulence potential in Haemophilus influenzae clinical strains.

Science.gov (United States)

Giucă, Mihaela Cristina; Străuţ, Monica; Surdeanu, Maria; Nica, Maria; Ungureanu, Vasilica; Mihăescu, Grigore

2011-01-01

Ten Haemophilus influenzae strains were isolated from patients aged between 1.6 - 24 years, with various diagnoses (acute meningitis, acute upper respiratory infection, otitis media and acute sinusitis). Identification was based on phenotypic and molecular characteristics; antibiotic susceptibility testing was performed by diffusion method according to CLSI standards 2011 for seven antibiotics. The results of molecular testing showed that all the studied strains produced an amplicon of 1000 bp with ompP2 primers indicating that all strains were H. influenzae. For six strains, the PCR amplicon obtained with bexA specific primers, proving that the strains were capsulated. The results of phenotypic testing showed that four strains were ampicillin nonsusceptible and (beta-lactamase-positive. The virulence potential of H. influenzae clinical strains was investigated by phenotypic methods, including the assessment of the soluble virulence factors on specific media containing the biochemical substratum for the investigated enzymatic factor, as well as the adherence and invasion capacity to HeLa cells monolayer using Cravioto modified method. The studied strains exhibited mainly a diffuse adherence pattern and different adherence indexes. Interestingly, two strains isolated from the same pacient (blood and CSF) showed a different degree of invasiveness, the strain isolated from blood being 20 times more invasive than the one isolated from CSF.

To tilfaelde af invasive infektioner med Haemophilus influenzae type f

DEFF Research Database (Denmark)

Nielsen, Jette Dettmann; Lind, Jens Wentzel; Bruun, Britta

2009-01-01

Two cases of invasive Haemophilus influenzae type f infection are presented: a three-week-old boy with meningitis and a 62-year-old woman with arthritis and bacteremia. Since 1993 vaccination against H. influenzae type b (Hib) has been offered to Danish children. The result has been a remarkable...... decrease in invasive Hib disease. However, physicians need to be aware of the existence of non-type b invasive H. influenzae disease. Udgivelsesdato: 2009-Jan...

To tilfaelde af invasive infektioner med Haemophilus influenzae type f

DEFF Research Database (Denmark)

Nielsen, Jette Dettmann; Lind, Jens; Bruun, Brita

2009-01-01

Two cases of invasive Haemophilus influenzae type f infection are presented: a three-week-old boy with meningitis and a 62-year-old woman with arthritis and bacteremia. Since 1993 vaccination against H. influenzae type b (Hib) has been offered to Danish children. The result has been a remarkable...... decrease in invasive Hib disease. However, physicians need to be aware of the existence of non-type b invasive H. influenzae disease. Udgivelsesdato: 2009-Jan-19...

Ampicillin Resistance and Outcome Differences in Acute Antepartum Pyelonephritis

Directory of Open Access Journals (Sweden)

Laura G. Greer

2008-01-01

Full Text Available Objective. To measure the incidence of ampicillin-resistant uropathogens in acute antepartum pyelonephritis and to determine if patients with resistant organisms had different clinical outcomes. Study design. This was a secondary analysis of a prospective cohort study of pregnant women admitted with pyelonephritis, diagnosed by standard clinical and laboratory criteria. All patients received ampicillin and gentamicin. Results. We identified 440 cases of acute pyelonephritis. Seventy-two percent (316 cases had urine cultures with identification of organism and antibiotic sensitivities. Fifty-one percent of uropathogens were ampicillin resistant. The patients with ampicillin-resistant organisms were more likely to be older and multiparous. There were no significant differences in hospital course (length of stay, days of antibiotics, ECU admission, or readmission. Patients with ampicillin-resistant organisms did not have higher complication rates (anemia, renal dysfunction, respiratory insufficiency, or preterm birth. Conclusion. A majority of uropathogens were ampicillin resistant, but no differences in outcomes were observed in these patients.

Invasive Haemophilus Influenzae Disease, Europe, 1996–2006

Centers for Disease Control (CDC) Podcasts

This podcast describes monitoring of Haemophilus influenzae disease in Europe from 1996 through 2006. CDC epidemiologist Stacey Martin discusses what researchers learned about the effect of vaccination on disease prevalence.

Emergence of ampicillin-resistant Enterococcus faecium in Danish hospitals

DEFF Research Database (Denmark)

Lester, Camilla H; Sandvang, Dorthe; Olsen, Stefan

2008-01-01

BACKGROUND: Ampicillin-resistant Enterococcus faecium isolates are reported in increasing numbers in many European hospitals. The clonal complex 17 (CC17) characterized by ampicillin resistance has been associated with nosocomial E. faecium outbreaks and infections in five continents. The aim...... in the number of infections caused by enterococci was observed from 2002 through 2006. The increase was mainly caused by E. faecium isolates, which tripled, whereas the number of E. faecalis isolates increased by only 23% during the same period. There was also a significant increase in the number of ampicillin......-resistant E. faecium isolates. MLST showed that 98% of the tested ampicillin-resistant E. faecium isolates belonged to CC17. PFGE showed eight different clusters and we found indications of clonal spread within the hospitals. CONCLUSIONS: Ampicillin-resistant E. faecium isolates have increased in frequency...

Lower airway colonization and inflammatory response in COPD: a focus on Haemophilus influenzae

Directory of Open Access Journals (Sweden)

Finney LJ

2014-10-01

Full Text Available Lydia J Finney,1 Andrew Ritchie,1 Elizabeth Pollard,2 Sebastian L Johnston,1 Patrick Mallia1 1Airway Disease Infection Section, National Heart and Lung Institute, Imperial College, London, United Kingdom; 2King's College London, London, United Kingdom Abstract: Bacterial infection of the lower respiratory tract in chronic obstructive pulmonary disease (COPD patients is common both in stable patients and during acute exacerbations. The most frequent bacteria detected in COPD patients is Haemophilus influenzae, and it appears this organism is uniquely adapted to exploit immune deficiencies associated with COPD and to establish persistent infection in the lower respiratory tract. The presence of bacteria in the lower respiratory tract in stable COPD is termed colonization; however, there is increasing evidence that this is not an innocuous phenomenon but is associated with airway inflammation, increased symptoms, and increased risk for exacerbations. In this review, we discuss host immunity that offers protection against H. influenzae and how disturbance of these mechanisms, combined with pathogen mechanisms of immune evasion, promote persistence of H. influenzae in the lower airways in COPD. In addition, we examine the role of H. influenzae in COPD exacerbations, as well as interactions between H. influenzae and respiratory virus infections, and review the role of treatments and their effect on COPD outcomes. This review focuses predominantly on data derived from human studies but will refer to animal studies where they contribute to understanding the disease in humans. Keywords: chronic obstructive pulmonary disease, Haemophilus influenzae, nontypeable Haemophilus influenzae, respiratory viruses, vaccination

Fallos vacunales a vacunas conjugadas de Streptococcus pneumoniae y Haemophilus influenzae tipo b

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Gonzalo Angulo

2016-11-01

Full Text Available Haemophilus influenzae type b and Streptococcus pneumoniae are the main cause agents of otitis, pneumonia, sepsis and meningitis, affecting mainly children under 5 years. Conjugate vaccines for encapsulated germs have dramatically decreased, the various diseases caused by these germs. Despite the decrease in morbidity and mortality, vaccine failures were observed. Children who experienced vaccine failures to Haemophilus influenzae type b had associated comorbidities more frequently than the general population (prematurity, HIV, Down syndrome, tumors, etc.. Nevertheless, most of these children have no medical history or immunological disorders. There is no consensus on whether all patients with vaccine failures should be assessed immunologically and how. There are recommendations to indicate a booster dose to patients with certain comorbidities and patients experiencing vaccine failure even in the absence of theses. Of the vaccine preparations available for Haemophilus influenzae type b association with acellular Bordetella pertussis proved to be less immunogenic and is currently being discouraged. Streptococcus pneumoniae serotypes 6B and 19F are less immunogenics and explain most of the vaccine failures in some series.

Safety and immunogenicity of two Haemophilus influenzae type b ...

African Journals Online (AJOL)

Objectives. Haemophilus influenzae type b (Hib) infection remains a major public health problem inthe developing world. We evaluated the safety and immunogenicity of a new PRP-CRM197 conjugate Hib vaccine (Vaxem Hib, Chiron Vacdnes), compared with theHibTITER vaccine (WyethLederle Vaccines), following the ...

In Vitro Capability of Faropenem To Select for Resistant Mutants of Streptococcus pneumoniae and Haemophilus influenzae▿ †

Science.gov (United States)

Kosowska-Shick, Klaudia; Clark, Catherine; Credito, Kim; Dewasse, Bonifacio; Beachel, Linda; Ednie, Lois; Appelbaum, Peter C.

2008-01-01

When tested against nine strains of pneumococci and six of Haemophilus influenzae of various resistotypes, faropenem failed to select for resistant mutants after 50 days of consecutive subculture in subinhibitory concentrations. Faropenem also yielded low rates of spontaneous mutations against all organisms of both species. By comparison, resistant clones were obtained with macrolides, ketolides, and quinolones. PMID:18086853

[Severe Haemophilus influenzae b infection in healthy male adult

DEFF Research Database (Denmark)

Vilmar, A.C.; Gjorup, I.; David, Kim Peter

2008-01-01

Haemophilus influenzae b (Hib) can be the cause of serious infections, and is mainly observed affecting children and immuno-compromised patients. We report a case of a healthy 49-year old male with a severe Hib infection complicated by septicaemia, meningitis and anuria. The risk of invasive Hib...

Characterization of the rec-1 gene of Haemophilus influenzae and behavior of the gene in Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Setlow, J.K.; Spikes, D.; Griffin, K.

1988-09-01

The rec-1 gene of Haemophilus influenzae was cloned into a shuttle vector that replicates in Escherichia coli as well as in H. influenzae. The plasmid, called pRec1, complemented the defects of a rec-1 mutant in repair of UV damage, transformation, and ability of prophage to be induced by UV radiation. Although UV resistance and recombination were caused by pRec1 in E. coli recA mutants, UV induction of lambda and UV mutagenesis were not. We suggest that the ability of the H. influenzae Rec-1 protein to cause cleavage of repressors but not the recombinase function differs from that of the E. coli RecA protein.

Characterization of the rec-1 gene of Haemophilus influenzae and behavior of the gene in Escherichia coli

International Nuclear Information System (INIS)

Setlow, J.K.; Spikes, D.; Griffin, K.

1988-01-01

The rec-1 gene of Haemophilus influenzae was cloned into a shuttle vector that replicates in Escherichia coli as well as in H. influenzae. The plasmid, called pRec1, complemented the defects of a rec-1 mutant in repair of UV damage, transformation, and ability of prophage to be induced by UV radiation. Although UV resistance and recombination were caused by pRec1 in E. coli recA mutants, UV induction of lambda and UV mutagenesis were not. We suggest that the ability of the H. influenzae Rec-1 protein to cause cleavage of repressors but not the recombinase function differs from that of the E. coli RecA protein

Frequent carriage of resistance mechanisms to beta-lactams and biofilm formation in Haemophilus influenzae causing treatment failure and recurrent otitis media in young children

NARCIS (Netherlands)

Garcia-Cobos, Silvia; Moscoso, Miriam; Pumarola, Felix; Arroyo, Margarita; Lara, Noelia; Perez-Vazquez, Maria; Aracil, Belen; Oteo, Jesus; Garcia, Ernesto; Campos, Jose

Objectives: Non-typeable Haemophilus influenzae are a major cause of acute otitis media (AOM), including chronic and recurrent otitis in young children. The objective of this study was to determine whether non-typeable H. influenzae isolates causing these infections produce biofilms and carry

Quorum signaling and sensing by nontypeable Haemophilus influenzae.

Science.gov (United States)

Swords, W Edward

2012-01-01

Quorum signals are diffusible factors produced by bacteria that coordinate communal responses. For nontypeable Haemophilus influenzae (NTHi), a series of recent papers indicate that production and sensing of quorum signals are determinants of biofilm formation/maturation and persistence in vivo. In this mini-review I will summarize the current knowledge about quorum signaling/sensing by this organism, and identify specific topics for additional study.

Carrier state of Haemophilus influenzae type b (Hib, Streptococcus pneumoniae, Streptococcus pyogenes, Neisseria meningitidis and Corynebacterium diphtheriae among school children in Pokhara, Nepal

Directory of Open Access Journals (Sweden)

Dharm Raj Bhatta

2014-02-01

Full Text Available Objective: To determine the incidence of carrier state of Haemophilus influenzae type b, Streptococcus pneumoniae (S. pneumoniae, Streptococcus pyogenes, Neisseria meningitidis and Corynebacterium diphtheriae among school children. Methods: Specimen from posterior pharyngeal wall and tonsils were collected on calcium alginate coated swabs from 1 02 participants. Processing of specimen and antimicrobial susceptibility testing was done by standard procedures. Results: Potential pathogens isolated in our study were S. pneumoniae (14.7%, Staphylococcus aureus (12.7%, Corynebacterium diphtheriae (3.9%, Streptococcus pyogenes (3.9% and Haemophilus influenzae (1.9%. Important findings in antibiogram include high resistance of S. pneumoniae to penicillin (73% and resistance of Staphylococcus aureus to oxacillin (23%. Conclusions: Pharyngeal colonization by S. pneumoniae among school children was found high and there is need of introduction of pneumococcal vaccines among children. Despite expected universal vaccination, pharyngeal colonization by Corynebacterium diphtheriae is possible and there is possibility of transmission.

Paracytosis of Haemophilus influenzae through cell layers of NCI-H292 lung epithelial cells

NARCIS (Netherlands)

van Schilfgaarde, M.; van Alphen, L.; Eijk, P.; Everts, V.; Dankert, J.

1995-01-01

Haemophilus influenzae penetrates the respiratory epithelium during carriage and invasive disease, including respiratory tract infections. We developed an in vitro model system consisting of lung epithelial NCI-H292 cells on permeable supports to study the passage of H. influenzae through lung

Tipificación capsular mediante PCR de aislamientos de Haemophilus influenzae no tipificables por aglutinación PCR-based capsular typing of Haemophilus influenzae isolates non-typeable by agglutination

Directory of Open Access Journals (Sweden)

G. Weltman

2005-12-01

Full Text Available Haemophilus influenzae es reconocido como un agente patógeno responsable de infecciones localizadas y sistémicas. Se han descrito 6 tipos de polisacáridos capsulares antigénicamente distintos (a, b, c, d, e, y f que se pueden identificar por aglutinación en lámina con antisueros específicos. También existen cepas no capsuladas (NC fenotípicamente no tipificables (NT. La introducción de la vacuna conjugada produjo una marcada disminución de las enfermedades invasivas causadas por H. influenzae tipo b. En este contexto, la tipificación capsular mediante PCR es el método más apropiado para distinguir las cepas no capsuladas de las mutantes b deficientes en cápsula (b- y detectar la presencia de cepas pertenecientes a otros serotipos que no puedan ser tipificables por aglutinación. Se determinó el genotipo capsular a 38 aislamientos de Haemophilus influenzae no tipificables por aglutinación, derivados al servicio de Bacteriología Clínica del INEI-ANLIS "Dr. Carlos G. Malbrán" en el período 2002-2004. El 78,9% de los aislamientos provenían de hemocultivos y la mayor parte de ellos estaban asociados a foco respiratorio. El 100% de los aislamientos fueron identificados como H. influenzae no capsulados mediante la técnica de PCR.Haemophilus influenzae is recognized as a pathogenic agent responsible of localized and systemic infections. Six antigenically different capsular polysaccharide types have been described (a, b, c, d, e, and f which can be identified by slide agglutination with specific antisera. Besides there are non capsulated strains that cannot be typed by slide agglutination. The introduction of the conjugated vaccine produced an important reduction of invasive diseases caused by H. influenzae type b. Capsular typing by PCR is the most appropriated method for distinguishing non capsulated strains from capsule deficient type b mutants (b- and for detecting strains of other serotypes that cannot be detected by slide

Antibiotic Resistance in Haemophilus influenzae Decreased, except for β-Lactamase-Negative Amoxicillin-Resistant Isolates, in Parallel with Community Antibiotic Consumption in Spain from 1997 to 2007▿

Science.gov (United States)

García-Cobos, Silvia; Campos, José; Cercenado, Emilia; Román, Federico; Lázaro, Edurne; Pérez-Vázquez, María; de Abajo, Francisco; Oteo, Jesús

2008-01-01

The susceptibility to 14 antimicrobial agents and the mechanisms of aminopenicillin resistance were studied in 197 clinical isolates of Haemophilus influenzae—109 isolated in 2007 (study group) and 88 isolated in 1997 (control group). Community antibiotic consumption trends were also examined. H. influenzae strains were consecutively isolated from the same geographic area, mostly from respiratory specimens from children and adults. Overall, amoxicillin resistance decreased by 8.4% (from 38.6 to 30.2%). β-Lactamase production decreased by 15.6% (from 33 to 17.4%, P = 0.01), but amoxicillin resistance without β-lactamase production increased by 7.1% (from 5.7 to 12.8%). All β-lactamase-positive isolates were TEM-1, but five different promoter regions were identified, with Pdel being the most prevalent in both years, and Prpt being associated with the highest amoxicillin resistance. A new promoter consisting of a double repeat of 54 bp was detected. Community consumption of most antibiotics decreased, as did the geometric means of their MICs, but amoxicillin-clavulanic acid and azithromycin consumption increased by ca. 60%. For amoxicillin-clavulanic acid, a 14.2% increase in the population with an MIC of 2 to 4 μg/ml (P = 0.02) was observed; for azithromycin, a 21.2% increase in the population with an MIC of 2 to 8 μg/ml (P = 0.0005) was observed. In both periods, the most common gBLNAR (i.e., H. influenzae isolates with mutations in the ftsI gene as previously defined) patterns were IIc and IIb. Community consumption of trimethoprim-sulfamethoxazole decreased by 54%, while resistance decreased from 50 to 34.9% (P = 0.04). Antibiotic resistance in H. influenzae decreased in Spain from 1997 to 2007, but surveillance should be maintained since new forms of resistances may be developing. PMID:18505850

Haemophilus segnis endocarditis

DEFF Research Database (Denmark)

Bangsborg, Jette Marie; Tvede, M; Skinhøj, P

1988-01-01

Haemophilus segnis is a rarely recognised commensal in the oropharynx. We wish to report the first published case of endocarditis caused by H. segnis. The patient, a 76-year-old female did not recover until after 2 courses of ampicillin given for a total of 57 days. In the second course of treatm......Haemophilus segnis is a rarely recognised commensal in the oropharynx. We wish to report the first published case of endocarditis caused by H. segnis. The patient, a 76-year-old female did not recover until after 2 courses of ampicillin given for a total of 57 days. In the second course...

Haemophilus influenzae Sepsis and Placental Abruption in an Unvaccinated Immigrant

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Paul A. Calner

2012-04-01

Full Text Available Background: Haemophilus influenzae infections have declined dramatically in the United States sinceimplementation of the conjugate vaccine. However, in countries where widespread immunization is notroutine, H influenzae remains a significant cause of morbidity and mortality. We report a case of apreviously unvaccinated immigrant with confirmed H influenzae sepsis and placental abruption leadingto spontaneous abortion.Objectives: To alert emergency medicine practitioners that H influenzae should be recognized as amaternal, fetal, and neonatal pathogen. Clinicians should consider this diagnosis in immigrants presentingwith uncertain vaccination history, as H influenzae can cause significant morbidity and mortality.Case Presentation: A 36-year-old female was referred to our emergency department (ED with lowerabdominal pain with some vaginal spotting. The patient had an initial visit with normal laboratoryinvestigations and normal imaging results, with complete resolution of symptoms. The patient returned tothe ED with sudden onset of vaginal bleeding and abdominal pain. She presented at this time with sepsis,which progressed to septic shock, causing placental abruption and ultimately, spontaneous abortion. Thepatient was treated with pressors and antibiotics and was admitted to the medical intensive care unitwhere she received ampicillin, gentamycin, and clindamycin for suspected chorioamnionitis. The patient’sblood cultures came back positive after 1 day for H influenzae. The patient did well and was dischargedfrom the hospital 4 days later.Conclusion: Haemophilus influenzae should be recognized as a neonatal and maternal pathogen.Clinicians should consider this diagnosis in immigrants presenting with uncertain vaccination history,especially in pregnant females, as H influenzae can cause significant morbidity and mortality. [West JEmerg Med. 2012;13(1:133–135.

Divergent mechanisms for passive pneumococcal resistance to β-lactam antibiotics in the presence of Haemophilus influenzae.

Science.gov (United States)

Weimer, Kristin E D; Juneau, Richard A; Murrah, Kyle A; Pang, Bing; Armbruster, Chelsie E; Richardson, Stephen H; Swords, W Edward

2011-02-15

Otitis media, for which antibiotic treatment failure is increasingly common, is a leading pediatric public health problem. In vitro and in vivo studies using the chinchilla model of otitis media were performed using a β-lactamase-producing strain of nontypeable Haemophilus influenzae (NTHi 86-028NP) and an isogenic mutant deficient in β-lactamase production (NTHi 86-028NP bla) to define the roles of biofilm formation and β-lactamase production in antibiotic resistance. Coinfection studies were done with Streptococcus pneumoniae to determine if NTHi provides passive protection by means of β-lactamase production, biofilm formation, or both. NTHi 86-028NP bla was resistant to amoxicillin killing in biofilm studies in vitro; however, it was cleared by amoxicillin treatment in vivo, whereas NTHi 86-028NP was unaffected in either system. NTHi 86-028NP protected pneumococcus in vivo in both the effusion fluid and bullar homogenate. NTHi 86-028NP bla and pneumococcus were both recovered from the surface-associated bacteria of amoxicillin-treated animals; only NTHi 86-028NP bla was recovered from effusion. Based on these studies, we conclude that NTHi provides passive protection for S. pneumoniae in vivo through 2 distinct mechanisms: production of β-lactamase and formation of biofilm communities.

A review of the role of Haemophilus influenzae in community-acquired pneumonia

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Mary PE Slack

2015-06-01

Full Text Available In an era when Haemophilus influenzae type b (Hib conjugate vaccine is widely used, the incidence of Hib as a cause of community-acquired pneumonia (CAP has dramatically declined. Non-typeable H. influenzae (NTHi strains and, occasionally, other encapsulated serotypes of H. influenzae are now the cause of the majority of invasive H. influenzae infections, including bacteraemic CAP. NTHi have long been recognised as an important cause of lower respiratory tract infection, including pneumonia, in adults, especially those with underlying diseases. The role of NTHi as a cause of non-bacteraemic CAP in children is less clear. In this review the evidence for the role of NTHi and capsulated strains of H. influenzae will be examined.

Impacto da vacinação contra o Haemophilus influenzae b na redução de meningites, Goiás

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Simões Luciana Leite Pineli

2004-01-01

Full Text Available OBJETIVO: Avaliar o impacto da vacinação contra o Haemophilus influenzae b na incidência de meningites em crianças menores de cinco anos de idade. MÉTODOS: Utilizou-se o delineamento tipo "antes-depois" para comparar as taxas de incidência de meningites por Haemophilus influenzae b nos períodos pré-vacinação (julho/95-junho/99 e pós-vacinação (julho/99-junho/2001 no Estado de Goiás. A definição de caso de meningite bacteriana seguiu os critérios da Organização Mundial de Saúde. As taxas de meningite por Streptococcus pneumoniae e Neisseria. meningitidis foram utilizadas para efeito de comparação. Para análise estatística foram utilizados o teste de chi2 e o t de Student. Valores de p<0,05 foram considerados estatisticamente significantes. RESULTADOS: Foi detectada meningite bacteriana aguda em 979 crianças no período de estudo. A incidência de meningite por Haemophilus influenzae b diminuiu de 10,8x10(5 no período pré-vacinal para 2,3x10(5 no segundo ano pós-vacina, significando 78% de redução no risco, principalmente na faixa etária de 7-23 meses (p<0,05. Foram prevenidos 65 casos de meningite por Haemophilus influenzae b. Observou-se aumento na incidência de meningite por S. pneumoniae. Foi observada falha vacinal em um caso. CONCLUSÕES: Expressivo declínio da incidência de meningite por Haemophilus influenzae b foi detectado, precocemente, logo após o primeiro ano de introdução da vacina contra o Haemophilus influenzae b. Assim, se faz necessária a vigilância contínua com instrumental de alta acurácia para: (i detectar re-emergência do Haemophilus influenzae b; (ii avaliar possibilidade de falha vacinal; (iii identificar mudanças no padrão dos sorotipos do H. influenzae.

Quantitation of antibody-secreting cells in the blood after vaccination with Haemophilus influenzae type b conjugate vaccine

DEFF Research Database (Denmark)

Barington, T; Heilmann, C; Andersen, V

1990-01-01

The human B-lymphocyte response to protein-conjugated polysaccharide antigens has not previously been studied at the cellular level. In order to do so, we developed and evaluated haemolytic plaque-forming cell assays detecting Haemophilus influenzae type b (Hib) capsular polysaccharide-specific a......The human B-lymphocyte response to protein-conjugated polysaccharide antigens has not previously been studied at the cellular level. In order to do so, we developed and evaluated haemolytic plaque-forming cell assays detecting Haemophilus influenzae type b (Hib) capsular polysaccharide...

Invasive Haemophilus Influenzae Disease, Europe, 1996–2006

Centers for Disease Control (CDC) Podcasts

2010-03-15

This podcast describes monitoring of Haemophilus influenzae disease in Europe from 1996 through 2006. CDC epidemiologist Stacey Martin discusses what researchers learned about the effect of vaccination on disease prevalence.  Created: 3/15/2010 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID); National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 4/5/2010.

Immunological characterization of conjugated Haemophilus influenzae type b vaccine failure in infants

NARCIS (Netherlands)

Breukels, M. A.; Spanjaard, L.; Sanders, L. A.; Rijkers, G. T.

2001-01-01

Infant vaccination with conjugated Haemophilus influenzae type b (Hib) vaccine is highly effective in protecting against invasive Hib infections, but vaccine failures do occur. Twenty-one vaccine failures are reported since the introduction of the Hib conjugate vaccine in The Netherlands. Of the 14

The Lung Immune Response to Nontypeable Haemophilus influenzae (Lung Immunity to NTHi

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Paul T. King

2015-01-01

Full Text Available Haemophilus influenzae is divided into typeable or nontypeable strains based on the presence or absence of a polysaccharide capsule. The typeable strains (such as type b are an important cause of systemic infection, whilst the nontypeable strains (designated as NTHi are predominantly respiratory mucosal pathogens. NTHi is present as part of the normal microbiome in the nasopharynx, from where it may spread down to the lower respiratory tract. In this context it is no longer a commensal and becomes an important respiratory pathogen associated with a range of common conditions including bronchitis, bronchiectasis, pneumonia, and particularly chronic obstructive pulmonary disease. NTHi induces a strong inflammatory response in the respiratory tract with activation of immune responses, which often fail to clear the bacteria from the lung. This results in recurrent/persistent infection and chronic inflammation with consequent lung pathology. This review will summarise the current literature about the lung immune response to nontypeable Haemophilus influenzae, a topic that has important implications for patient management.

Antimicrobial susceptibility and serotypes of Actinobacillus (Haemophilus) pleuropneumoniae recovered from Missouri swine.

Science.gov (United States)

Fales, W H; Morehouse, L G; Mittal, K R; Bean-Knudsen, C; Nelson, S L; Kintner, L D; Turk, J R; Turk, M A; Brown, T P; Shaw, D P

1989-01-01

The antimicrobial susceptibility of 73 Actinobacillus (Haemophilus) pleuropneumoniae isolates from swine in Missouri was determined with a microdilution minimal inhibitory concentration test system. Serotyping was accomplished by means of co-agglutination. Serotype 1 (39/73) and serotype 5 (30/73) were commonly found, whereas serotype 7 (4/73) was infrequently encountered. Most isolates (MIC90) were found susceptible to ampicillin (amoxicillin), cephalothin, penicillin, erythromycin, gentamicin, and kanamycin. Marked resistance was found with oxytetracycline, tylosin, and sulfadimethoxine. The data indicate that use of ampicillin (amoxicillin) or penicillin may correlate well with the favorable outcome of treatment.

A comparative study of preservation and storage of Haemophilus influenzae

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Olga C Aulet de Saab

2001-05-01

Full Text Available The aim of this study was to compare the efficacy of conservation by freezing the strains of Haemophilus influenzae at -20ºC and -70ºC. Skim milk supplemented with glucose, yeast extract and glycerol allowed highest viability of H. influenzae both at -20ºC and -70ºC from the media analyzed. Trypticase soy broth and brain heart infusion broth supplemented with glycerol, allowed excellent recovery. Use of cotton swaps as supporting material, with or without addition of cryoprotective agents, did not modify H. influenzae viability after six months of storage. Concentration of the initial inoculum positively affected viability when stored at -20ºC. Initial concentration did not influence survival after storage at -70ºC. Thawing at room temperature should not exceed 3 h as to get highest survival percentage.

First Necrotizing Fasciitis Caused by Haemophilus influenza Serotype a

Science.gov (United States)

Quach, Giang T.; Frisby, Jared; Kralovich, Kurt; Bohra, Mustafa

2017-01-01

Necrotizing fasciitis (NF) is an infrequently encountered skin infection that has high morbidity and mortality, even with prompt medical and surgical intervention. We describe the case of a 67-year-old male presenting with significant NF in his left lower extremity, despite aggressive surgical intervention, and included multiple surgical debridements, ACell Matrix, split-thickness, and negative wound VAC therapy. Ultimately, this patient required a below the knee amputation. This is the first documented case of Haemophilus influenza type a causing NF. PMID:29124073

Detection of cryptic genospecies misidentified as Haemophilus influenzae in routine clinical samples by assessment of marker genes fucK, hap, and sodC.

Science.gov (United States)

Nørskov-Lauritsen, Niels

2009-08-01

Clinical isolates of Haemophilus influenzae were assessed for the presence of fucK, hap, and sodC by hybridization with gene-specific probes, and isolates diverging from the expected H. influenzae genotype were characterized by phenotype and 16S rRNA gene sequencing. Two of 480 isolates were finally classified as variant strains ("nonhemolytic Haemophilus haemolyticus").

Detection of Cryptic Genospecies Misidentified as Haemophilus influenzae in Routine Clinical Samples by Assessment of Marker Genes fucK, hap, and sodC▿

Science.gov (United States)

Nørskov-Lauritsen, Niels

2009-01-01

Clinical isolates of Haemophilus influenzae were assessed for the presence of fucK, hap, and sodC by hybridization with gene-specific probes, and isolates diverging from the expected H. influenzae genotype were characterized by phenotype and 16S rRNA gene sequencing. Two of 480 isolates were finally classified as variant strains (“nonhemolytic Haemophilus haemolyticus”). PMID:19535530

Vacinação contra Haemophilus influenzae tipo b: proteção a longo prazo Haemophilus influenzae type b vaccination: long term protection

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Cristiana M. Nascimento-Carvalho

2006-07-01

Full Text Available OBJETIVO: Identificar as evidências sobre o impacto da vacina conjugada para Haemophilus influenzae tipo b (Hib na epidemiologia da doença invasiva por Hib. FONTE DOS DADOS: Pesquisa nas bases de dados do MEDLINE, LILACS, publicações técnicas de organizações internacionais, diretrizes nacionais e internacionais, nos últimos 15 anos (1991-2005, utilizando os seguintes unitermos: Haemophilus influenzae type b, immunization, impact, effectiveness. Foram incluídas as publicações que apresentaram informação para atender o objetivo deste artigo. Artigos publicados em período anterior ao da pesquisa e citados em referências dos artigos incluídos foram analisados quanto à apresentação de informação de interesse. SÍNTESE DOS DADOS: A introdução da vacina conjugada para Hib produziu grande declínio na incidência de casos de doença invasiva por Hib nos diversos países em que seu uso foi incorporado à rotina de vacinação das crianças. No entanto, o ressurgimento de casos com doença invasiva por Hib tem mobilizado vários investigadores na busca das possíveis explicações para esses eventos, bem como a identificação das medidas a serem implementadas para evitar o reaparecimento da doença. CONCLUSÕES: O uso da vacina conjugada para Hib em escala populacional tem sido extremamente efetivo. No entanto, mudanças no esquema vacinal poderão ser necessárias para a manutenção do controle da doença invasiva por Hib, frente ao atual cenário epidemiológico das infecções pelo Hib.OBJECTIVE: To identify evidence of the impact of Haemophilus influenzae type b (Hib conjugate vaccine on the epidemiology of invasive Hib disease. SOURCES OF DATA: This review was based on a search of MEDLINE, LILACS, technical reports, national and international guidelines (publications from 1991 to 2005. The keywords Haemophilus influenzae type b, immunization, impact and effectiveness, alone or in combination, were used to retrieve the

Haemophilus paragallinarum in chickens in Indonesia: III. Antimicrobial drug sensitivity test ofHaemophilus paragallinarum from chickens suffering of coryza

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Sri Poernomo

1998-12-01

Full Text Available An agar disc diffusion method was used to examine the sensitivity of 27 Haemophilus paragallinarum (Hpg isolates consisted of 23 local isolates, 4 standard isolates (serotype A and Escherichia coli ATCC 24922 as a control to eight antimicrobial drugs (ampicillin, erythromycin, oxytetracycline, doxycycline, neomycin, streptomycin, colistine and sulphanlethoxazole-trimethoprim . Twenty one out of 23 local isolates of Hpg were sensitive to doxycycline, 19 isolates to ampsllin, 18 isolates to oxytetracycline, 17 isolates to sulphametoxazole-trimethoprim, 16 isolates to erythromycin, and 13 isolates to neomycin, while 13 isolates were resistance to colistine and 11 isolates were also resistance to streptomycin .

Indirect pathogenicity of Haemophilus influenzae and Moraxella catarrhalis in polymicrobial otitis media occurs via interspecies quorum signaling.

Science.gov (United States)

Armbruster, Chelsie E; Hong, Wenzhou; Pang, Bing; Weimer, Kristin E D; Juneau, Richard A; Turner, James; Swords, W Edward

2010-07-06

Otitis media (OM) is among the leading diseases of childhood and is caused by opportunists that reside within the nasopharynx, such as Haemophilus influenzae and Moraxella catarrhalis. As with most airway infections, it is now clear that OM infections involve multiple organisms. This study addresses the hypothesis that polymicrobial infection alters the course, severity, and/or treatability of OM disease. The results clearly show that coinfection with H. influenzae and M. catarrhalis promotes the increased resistance of biofilms to antibiotics and host clearance. Using H. influenzae mutants with known biofilm defects, these phenotypes were shown to relate to biofilm maturation and autoinducer-2 (AI-2) quorum signaling. In support of the latter mechanism, chemically synthesized AI-2 (dihydroxypentanedione [DPD]) promoted increased M. catarrhalis biofilm formation and resistance to antibiotics. In the chinchilla infection model of OM, polymicrobial infection promoted M. catarrhalis persistence beyond the levels seen in animals infected with M. catarrhalis alone. Notably, no such enhancement of M. catarrhalis persistence was observed in animals infected with M. catarrhalis and a quorum signaling-deficient H. influenzae luxS mutant strain. We thus conclude that H. influenzae promotes M. catarrhalis persistence within polymicrobial biofilms via interspecies quorum signaling. AI-2 may therefore represent an ideal target for disruption of chronic polymicrobial infections. Moreover, these results strongly imply that successful vaccination against the unencapsulated H. influenzae strains that cause airway infections may also significantly impact chronic M. catarrhalis disease by removing a reservoir of the AI-2 signal that promotes M. catarrhalis persistence within biofilm.

Meningitis - H. influenzae

Science.gov (United States)

H. influenzae meningitis; H. flu meningitis; Haemophilus influenzae type b meningitis ... H. influenzae meningitis is caused by Haemophilus influenzae type b bacteria. This illness is not the same ...

Structure-based functional annotation of putative conserved proteins having lyase activity from Haemophilus influenzae.

Science.gov (United States)

Shahbaaz, Mohd; Ahmad, Faizan; Imtaiyaz Hassan, Md

2015-06-01

Haemophilus influenzae is a small pleomorphic Gram-negative bacteria which causes several chronic diseases, including bacteremia, meningitis, cellulitis, epiglottitis, septic arthritis, pneumonia, and empyema. Here we extensively analyzed the sequenced genome of H. influenzae strain Rd KW20 using protein family databases, protein structure prediction, pathways and genome context methods to assign a precise function to proteins whose functions are unknown. These proteins are termed as hypothetical proteins (HPs), for which no experimental information is available. Function prediction of these proteins would surely be supportive to precisely understand the biochemical pathways and mechanism of pathogenesis of Haemophilus influenzae. During the extensive analysis of H. influenzae genome, we found the presence of eight HPs showing lyase activity. Subsequently, we modeled and analyzed three-dimensional structure of all these HPs to determine their functions more precisely. We found these HPs possess cystathionine-β-synthase, cyclase, carboxymuconolactone decarboxylase, pseudouridine synthase A and C, D-tagatose-1,6-bisphosphate aldolase and aminodeoxychorismate lyase-like features, indicating their corresponding functions in the H. influenzae. Lyases are actively involved in the regulation of biosynthesis of various hormones, metabolic pathways, signal transduction, and DNA repair. Lyases are also considered as a key player for various biological processes. These enzymes are critically essential for the survival and pathogenesis of H. influenzae and, therefore, these enzymes may be considered as a potential target for structure-based rational drug design. Our structure-function relationship analysis will be useful to search and design potential lead molecules based on the structure of these lyases, for drug design and discovery.

Isolation of Haemophilus influenzae and Haemophilus parainfluenzae in urethral exudates from men with acute urethritis: a descriptive study of 52 cases.

Science.gov (United States)

Deza, Gustavo; Martin-Ezquerra, Gemma; Gómez, Julià; Villar-García, Judit; Supervia, August; Pujol, Ramon M

2016-02-01

To describe the clinical characteristics and therapeutic outcomes from male patients diagnosed of Haemophilus spp urethritis. A chart review of patients who presented to our hospital from January 2013 to December 2014 with symptoms of acute urethritis in which Haemophilus spp was isolated in their urethral samples was performed. Haemophilus spp was isolated in 52 out of 413 urethral samples (12.6%) received in our laboratory from patients with symptoms of acute urethritis during the study period. Seven cases corresponded to Haemophilus influenzae and 45 cases to Haemophilus parainfluenzae. The most common clinical presentation was mucopurulent urethral discharge (71%). Eight per cent were HIV-infected patients, and 60% were men who have sex with men. Haemophilus spp was isolated as a single pathogen in 6.8% (28 of 413) of cases. Seventeen per cent of Haemophilus spp were β-lactamase producers. All patients reported having practiced unprotected insertive oral sex the month before consultation, and five of them denied having had another sexual contact apart from this exposure. In all cases in which follow-up was available, empirical treatment achieved a complete clinical resolution. Haemophilus spp was considered a pathogen in at least 6.8% of the patients from the evaluated area. It affected men regardless their sexual orientation or HIV status. Unprotected oral sex could play a role in its transmission. The limitations of the study (small sample size and lack of a representative control group) do not allow to prove the true pathogenic role of Haemophilus spp in acute urethritis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Simple test of synergy between ampicillin and vancomycin for resistant strains of Enterococcus faecium.

OpenAIRE

Green, M; Barbadora, K; Wadowsky, R M

1994-01-01

The combination of ampicillin and vancomycin kills some but not all strains of ampicillin- and vancomycin-resistant Enterococcus faecium. We compared a simple test for synergy utilizing a commercially available microdilution susceptibility system with time-kill studies and determined acceptable breakpoints for this test for 20 strains of ampicillin- and vancomycin-resistant E. faecium. The combination of ampicillin and vancomycin was tested for synergy by time-kill, broth macrodilution, and b...

Inflammatory response of Haemophilus influenzae biotype aegyptius causing Brazilian Purpuric Fever

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Gisele Cristiane Gentile Cury

2014-12-01

Full Text Available The Brazilian Purpuric Fever (BPF is a systemic disease with many clinical features of meningococcal sepsis and is usually preceded by purulent conjunctivitis. The illness is caused by Haemophilus influenza biogroup aegyptius, which was associated exclusively with conjunctivitis. In this work construction of the las gene, hypothetically responsible for this virulence, were fusioned with ermAM cassette in Neisseria meningitidis virulent strains and had its DNA transfer to non BPF H. influenzae strains. The effect of the las transfer was capable to increase the cytokines TNFα and IL10 expression in Hec-1B cells line infected with these transformed mutants (in eight log scale of folding change RNA expression. This is the first molecular study involving the las transfer to search an elucidation of the pathogenic factors by horizontal intergeneric transfer from meningococci to H. influenzae.

Streptococcus pneumoniae and Haemophilus influenzae as etiological agents of conjunctivitis outbreaks in the region of Ribeirão Preto, SP, Brazil

Directory of Open Access Journals (Sweden)

Marta I. C. MEDEIROS

1998-01-01

Full Text Available In the study of conjunctivitis outbreaks occurring from September 1994 to September 1996 in the region of Ribeirão Preto, conjunctival exudates of 92 patients were cultivated in Instituto Adolfo Lutz Laboratory I, Ribeirão Preto. Most cases occurred in the age range 2-7 years. The etiological agents which were most frequently isolated from the analyzed cases were: Streptococcus pneumoniae and Haemophilus influenzae, in 40.22% and 21.74%, respectively. 51.35% of the S. pneumoniae isolated strains were not typable. The oxacillin-resistant S. pneumoniae strains were submitted to the minimum inhibitory concentration test (MIC and three of them presented intermediate resistance, whereas only one was highly resistant to penicillin.No estudo de surtos de conjuntivite ocorridos no período de setembro de 1994 a setembro de 1996, na região de Ribeirão Preto, foram semeadas no Instituto Adolfo Lutz Laboratório I, Ribeirão Preto, exsudatos conjuntivais de 92 pacientes, sendo que a maioria dos casos estava na faixa etária de 2-7 anos. Os agentes etiológicos mais freqüentemente isolados dos casos analisados foram: Streptococcus pneumoniae e Haemophilus influenzae em 40,22% e 21,74% respectivamente. 51,35% das cepas de S. pneumoniae isoladas foram não tipáveis. As cepas de S. pneumoniae oxacilina resistente foram submetidas ao teste de concentração inibitória mínima (CIM, sendo que três apresentaram resistência intermediária e apenas uma foi altamente resistente à penicilina.

Detection of Haemophilus influenzae in respiratory secretions from pneumonia patients by quantitative real-time polymerase chain reaction.

Science.gov (United States)

Abdeldaim, Guma M K; Strålin, Kristoffer; Kirsebom, Leif A; Olcén, Per; Blomberg, Jonas; Herrmann, Björn

2009-08-01

A quantitative real-time polymerase chain reaction (PCR) based on the omp P6 gene was developed to detect Haemophilus influenzae. Its specificity was determined by analysis of 29 strains of 11 different Haemophilus spp. and was compared with PCR assays having other target genes: rnpB, 16S rRNA, and bexA. The method was evaluated on nasopharyngeal aspirates from 166 adult patients with community-acquired pneumonia. When 10(4) DNA copies/mL was used as cutoff limit for the method, P6 PCR had a sensitivity of 97.5% and a specificity of 96.0% compared with the culture. Of 20 culture-negative but P6 PCR-positive cases, 18 were confirmed by fucK PCR as H. influenzae. Five (5.9%) of 84 nasopharyngeal aspirates from adult controls tested PCR positive. We conclude that the P6 real-time PCR is both sensitive and specific for identification of H. influenzae in respiratory secretions. Quantification facilitates discrimination between disease-causing H. influenzae strains and commensal colonization.

Clinical characteristics of Haemophilus influenzae meningitis in Denmark in the post-vaccination era

DEFF Research Database (Denmark)

Pedersen, T.I.; Howitz, M.; Andersen, Christian Østergaard

2010-01-01

P>The introduction of Haemophilus influenzae type b (Hib) vaccine into the Danish childhood vaccination programme in 1993 may have influenced the epidemiology of H. influenzae meningitis (i.e. increasing frequency of other non-vaccine types; presentation in other age groups). Based on nationwide...... registration, clinical information and laboratory findings were collected from all 65 confirmed cases of H. influenzae meningitis during the period 1994-2005. Twenty-nine patients (45%) were 24 years old [median 62 years (range 25...... infected with Hib, two cases (13%) were identified as true vaccine failures. Six patients (9%) died; one premature infant infected with serotype f and five adults (age 83-96 years) with non-typeable H. influenzae. Hearing loss was reported in 16% of the surviving children and in 10% of the surviving adults...

The capsule biosynthesis locus of Haemophilus influenzae show conspicuous similarity to the corresponding locus in Haemophilus sputorum and may have been recruited from this species by horizontal gene transfer

DEFF Research Database (Denmark)

Nielsen, Signe Maria; de Gier, Camilla; Dimopoulou, Chrysoula

2015-01-01

in export and processing of the capsular material, show high similarity to the corresponding genes in capsulate lineages of the pathogenic species Haemophilus influenzae; indeed, standard bexA and bexB PCRs for detection of capsulated strains of H. influenzae give positive results with strains of H....... sputorum was only distantly related to H. influenzae. In contrast to H. influenzae, the capsule locus in H. sputorum is not associated with transposases or other transposable elements. Our data suggest that the capsule locus of capsulate lineages of H. influenzae may relatively recently have been recruited...

Frequency of Streptococcus pneumonia and Haemophilus influenza in acute exacerbation of chronic obstructive airway disease and their sensitivity to levofloxacin

International Nuclear Information System (INIS)

Furqan, S.; Paracha, S.A.U.

2014-01-01

Objective: To determine the frequency of Streptococcus pneumoniae and Haemophilus influenzae in acute exacerbation of chronic obstructive pulmonary disease and their sensitivity to levofloxacin. Methods: The cross-sectional study was conducted at the Department of Medicine, AbbasiShaheed Hospital, Karachi, between July 2009 and January 2010. Patients already diagnosed with chronic obstructive pulmonary disease and admitted with symptoms of acute exacerbation were included in the study and their sputum samples were sent for microbiological evaluation. SPSS 16 was used for statistical analysis. Results: Of the total 105 patients in the study, 90 (85.17%) were males. Overall mean age at presentation was 62+-10.2 years. S. pneumoniae was isolated from sputum culture of 33 (31.4%) patients, while 13 (12.4%) patients showed growth of H. influenzae. Out of the 33 sputum specimens of S. pneumoniae, 32 (97.0%) were sensitive to levofloxacin, while 1 (3.0%) was resistant. All the 13 isolates of H. influenzae were sensitive to levofloxacin. Conclusion: S. pneumoniae and H. influenzae are still the most prevalent organisms isolated in acute exacerbation of chronic obstructive pulmonary disease in our population. Levofloxacin is still considered a highly sensitive antibiotic against these common micro-organisms in our population, but S. pneumoniae has started developing resistance against levofloxacin. Therefore, intermittent surveillance regarding development of resistance pattern of common micro-organisms against commonly prescribed antibiotics is required. (author)

Serious systemic infection caused by non-encapsulated Haemophilus influenzae biotype III in an adult

DEFF Research Database (Denmark)

Lester, Anne; Pedersen, P B

1991-01-01

Haemophilus influenzae is the aetiological agent in less than 1% of septic arthritis cases in adults and most often serotype b is involved. We report here a case of severe systemic infection due to non-encapsulated H. influenzae biotype III in a 40-year-old man, previously healthy although alcohol...... abuser. Cholangitis and acute alcoholic hepatitis were diagnosed simultaneously. The organism was grown from blood and from synovial fluid of the left knee, but several other joints were also affected. The close relationship between H. influenzae biotype III and H. aegyptius is mentioned in view...... of recent reports of fatal childhood illness caused by a special clone of H. aegyptius and the importance of reporting both serotype and biotype in severe H. influenzae induced disease is emphasized....

Clonal relationship of recent invasive Haemophilus influenzae serotype f isolates from Denmark and the United States

DEFF Research Database (Denmark)

Bruun, B; Gahrn-Hansen, B; Westh, H

2004-01-01

Surveillance performed after the introduction of general Haemophilus influenzae serotype b (Hib) vaccination in Denmark identified 13 cases of invasive bacteraemic H. influenzae serotype f (Hif) disease in adults over a period of 7 years. Bacteraemic respiratory tract infections accounted for 61...... sequences. Multilocus enzyme electrophoresis typing revealed that recent Danish and American isolates belonged to a single Hif clone, which may be undergoing expansion. The need for accurate serotyping of H. influenzae to enable reliable monitoring for Hib replacement by other capsular types is emphasized....

Recurrent Posttraumatic Meningitis due to Nontypable Haemophilus influenzae: Case Report and Review of the Literature

DEFF Research Database (Denmark)

Kunze, W; Müller, L; Kilian, Mogens

2007-01-01

We report a case of relapsing Haemophilus influenzae meningitis in a boy at the age of nearly 3 years and 4.2 years who had been successfully vaccinated against H. influenzae serotype b (Hib). The pathogen was a nonencapsulated (nontypable) H. influenzae strain of biotypes III and VI, respectively....... A rhinobasal impalement injury with development of a posttraumatic encephalocele is considered to be the predisposing condition. Review of the literature reveals that in patients systemically infected by nonencapsulated H. influenzae strains predisposing factors such as cerebrospinal fluid-shunts, implants...... and traumas are often found. To obtain further information on potential new disease patterns H. influenzae isolates from cerebrospinal fluid should be examined for capsule production and, if relevant, further characterized by capsular typing....

Haemophilus influenzae type B genital infection and septicemia in pregnant woman: a case report

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Hosuru Subramanya Supram

2014-06-01

Full Text Available Haemophilus influenzae (H. influenzae type B a non-motile, aerobic, gram negative cocobacillus is a commensal of upper respiratory tract. Genitourinary infection due to H. influenzae has been reported but bacteremia associated with such infection appears to be rare. We report a case of 19 years young primigravida with complaints of amenorrhea of 32 weeks and 5 days, pyrexia, abdominal pain and blood stained discharge per vaginum. H. influenzae type B was recovered from the genital tract as well as blood of the mother indicating maternal septicemia. Septicemia caused by H. influenzae type B in pregnant women following vaginal colonization and infection is rare. It has been reported in many parts of world over the years; to the best of our knowledge this is the first reported case from Nepal. H. influenzae should be considered as a potential maternal, fetal, and neonatal pathogen.

Dps promotes survival of nontypeable Haemophilus influenzae in biofilm communities in vitro and resistance to clearance in vivo.

Science.gov (United States)

Pang, Bing; Hong, Wenzhou; Kock, Nancy D; Swords, W Edward

2012-01-01

Nontypeable Haemophilus influenzae (NTHi) is a common airway commensal and opportunistic pathogen that persists within surface-attached biofilm communities. In this study, we tested the hypothesis that bacterial stress-responses are activated within biofilms. Transcripts for several factors associated with bacterial resistance to environmental stress were increased in biofilm cultures as compared to planktonic cultures. Among these, a homolog of the DNA-binding protein from starved cells (dps) was chosen for further study. An isogenic NTHi 86-028NP dps mutant was generated and tested for resistance to environmental stress, revealing a significant survival defects in high-iron conditions, which was mediated by oxidative stress and was restored by genetic complementation. As expected, NTHi 86-028NP dps had a general stress-response defect, exhibiting decreased resistance to many types of environmental stress. While no differences were observed in density and structure of NTHi 86-028NP and NTHi 86-028NP dps biofilms, bacterial survival was decreased in NTHi 86-028NP dps biofilms as compared to the parental strain. The role of dps persistence in vivo was tested in animal infection studies. NTHi 86-028NP dps had decreased resistance to clearance after pulmonary infection of elastase-treated mice as compared to NTHi 86-028NP, whereas minimal differences were observed in clearance from mock-treated mice. Similarly, lower numbers of NTHi 86-028NP dps were recovered from middle-ear effusions and bullar homogenates in the chinchilla model for otitis media (OM). Therefore, we conclude that Dps promotes bacterial survival within NTHi biofilm communities both in vitro and in chronic infections in vivo.

Dps promotes survival of nontypeable Haemophilus influenzae in biofilm communities in vitro and resistance to clearance in vivo

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Bing ePang

2012-05-01

Full Text Available Nontypeable Haemophilus influenzae (NTHi is a common airway commensal and opportunistic pathogen that persists within surface-attached biofilm communities. In this study, we tested the hypothesis that bacterial stress-responses are activated within biofilms. Transcripts for several factors associated with bacterial resistance to environmental stress were increased in biofilm cultures as compared to planktonic cultures. Among these, a homolog of the DNA-binding protein from starved cells (dps was chosen for further study. An isogenic NTHi 86-028NP dps mutant was generated and tested for resistance to environmental stress, revealing a significant survival defects in high-iron conditions, which was mediated by oxidative stress and was restored by genetic complementation. As expected, NTHi 86-028NP dps had a general stress-response defect, exhibiting decreased resistance to many types of environmental stress. While no differences were observed in density and structure of NTHi 86-028NP and NTHi 86-028NP dps biofilms, bacterial survival was decreased in NTHi 86-028NP dps biofilms as compared to the parental strain. The role of dps persistence in vivo was tested in animal infection studies. NTHi 86-028NP dps had decreased resistance to clearance after pulmonary infection of elastase-treated mice as compared to NTHi 86-028NP, whereas minimal differences were observed in clearance from mock-treated mice. Similarly, lower numbers of NTHi 86-028NP dps were recovered from middle-ear effusions and bullar homogenates in the chinchilla model for otitis media. Therefore, we conclude that Dps promotes bacterial survival within NTHi biofilm communities both in vitro and in chronic infections in vivo.

Difficult identification of Haemophilus influenzae, a typical cause of upper respiratory tract infections, in the microbiological diagnostic routine.

Science.gov (United States)

Hinz, Rebecca; Zautner, Andreas Erich; Hagen, Ralf Matthias; Frickmann, Hagen

2015-03-01

Haemophilus influenzae is a key pathogen of upper respiratory tract infections. Its reliable discrimination from nonpathogenic Haemophilus spp. is necessary because merely colonizing bacteria are frequent at primarily unsterile sites. Due to close phylogenetic relationship, it is not easy to discriminate H. influenzae from the colonizer Haemophilus haemolyticus. The frequency of H. haemolyticus isolations depends on factors like sampling site, patient condition, and geographic region. Biochemical discrimination has been shown to be nonreliable. Multiplex PCR including marker genes like sodC, fucK, and hpd or sequencing of the 16S rRNA gene, the P6 gene, or multilocus-sequence-typing is more promising. For the diagnostic routine, such techniques are too expensive and laborious. If available, matrix-assisted laser-desorption-ionization time-of-flight mass spectrometry is a routine-compatible option and should be used in the first line. However, the used database should contain well-defined reference spectra, and the spectral difference between H. influenzae and H. haemolyticus is small. Fluorescence in-situ hybridization is an option for less well-equipped laboratories, but the available protocol will not lead to conclusive results in all instances. It can be used as a second line approach. Occasional ambiguous results have to be resolved by alternative molecular methods like 16S rRNA gene sequencing.

The Comparison of Haemophilus Influenza in the Throat of Healthy Infants with Different Feeding Methods

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A Kazemi

2004-06-01

Full Text Available Background: Haemophilus influenza (HI is the most commonly found pathogenic bacteria in pediatric otitis media and lower respiratory tract infections. Bacterial attachment to pharyngeal cells and proliferation may be necessary for infection. In the presence of human milk, attachment of HI to pharyngeal cells and colonization may be inhibited. To evaluate the protecting role of breast milk, we investigated the incidence of HI isolated from the throat of healthy infants with different feeding methods. Methods: Between August 2002 and March 2003, 210 healthy infants (70 purely breast-fed, 70 purely formula-fed, 70 mixed-fed, aged 1-6 months were enrolled into the study and a throat culture was taken in all of them. The incidence of HI was evaluated using Haemophilus Test Agar Bose (HTAB plates. Results: The incidence of HI in purely breast-fed, mixed-fed and purely formula-fed infants was 2.9%, 42.9% and 75.7% respectively (P = 0.000. The mean age and weight of cases in the three groups were not statistically different. Conclusion: These data suggest that human milk protects the throat of healthy infants from HI colonization especially in purely breast-fed cases. Keywords: Breast milk, Haemophilus influenza, Throat culture

Endogenous and exogenous reinfections by Haemophilus influenzae in patients with chronic obstructive pulmonary disease: the effect of antibiotic treatment on persistence

NARCIS (Netherlands)

Groeneveld, K.; van Alphen, L.; Eijk, P. P.; Visschers, G.; Jansen, H. M.; Zanen, H. C.

1990-01-01

To analyze whether exacerbations in chronic obstructive pulmonary disease (COPD) coincide with reinfection by Haemophilus influenzae, 16 COPD patients were studied longitudinally for 3 years. Exacerbations coincided with reinfection by H. influenzae, either endogenous, by a strain with a DNA

Contribution of the major and minor subunits to fimbria-mediated adherence of Haemophilus influenzae to human epithelial cells and erythrocytes

NARCIS (Netherlands)

van Ham, S. M.; van Alphen, L.; Mooi, F. R.; van Putten, J. P.

1995-01-01

Fimbriae are colonization factors of the human pathogen Haemophilus influenzae in that they mediate bacterial adherence to human eukaryotic cells. The contribution of the major (HifA) and putative minor (HifD and HifE) subunits of H. influenzae fimbriae to fimbria-specific adherence was studied by

Complete Deletion of the Fucose Operon in Haemophilus influenzae Is Associated with a Cluster in Multilocus Sequence Analysis-Based Phylogenetic Group II Related to Haemophilus haemolyticus: Implications for Identification and Typing.

Science.gov (United States)

de Gier, Camilla; Kirkham, Lea-Ann S; Nørskov-Lauritsen, Niels

2015-12-01

Nonhemolytic variants of Haemophilus haemolyticus are difficult to differentiate from Haemophilus influenzae despite a wide difference in pathogenic potential. A previous investigation characterized a challenging set of 60 clinical strains using multiple PCRs for marker genes and described strains that could not be unequivocally identified as either species. We have analyzed the same set of strains by multilocus sequence analysis (MLSA) and near-full-length 16S rRNA gene sequencing. MLSA unambiguously allocated all study strains to either of the two species, while identification by 16S rRNA sequence was inconclusive for three strains. Notably, the two methods yielded conflicting identifications for two strains. Most of the "fuzzy species" strains were identified as H. influenzae that had undergone complete deletion of the fucose operon. Such strains, which are untypeable by the H. influenzae multilocus sequence type (MLST) scheme, have sporadically been reported and predominantly belong to a single branch of H. influenzae MLSA phylogenetic group II. We also found evidence of interspecies recombination between H. influenzae and H. haemolyticus within the 16S rRNA genes. Establishing an accurate method for rapid and inexpensive identification of H. influenzae is important for disease surveillance and treatment. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Changes in outer membrane proteins of nontypable Haemophilus influenzae in patients with chronic obstructive pulmonary disease

NARCIS (Netherlands)

Groeneveld, K.; van Alphen, L.; Eijk, P. P.; Jansen, H. M.; Zanen, H. C.

1988-01-01

Five individual colonies of Haemophilus influenzae were isolated from each of one to three cultures of sputum collected from 18 patients with chronic obstructive pulmonary disease (COPD). The isolates were studied to investigate whether the major outer membrane proteins (MOMPs) changed during

Nontypeable Haemophilus influenzae initiates formation of neutrophil extracellular traps.

Science.gov (United States)

Juneau, Richard A; Pang, Bing; Weimer, Kristin E D; Armbruster, Chelsie E; Swords, W Edward

2011-01-01

Nontypeable Haemophilus influenzae (NTHI) is a leading cause of otitis media infections, which are often chronic and/or recurrent in nature. NTHI and other bacterial species persist in vivo within biofilms during otitis media and other persistent infections. These biofilms have a significant host component that includes neutrophil extracellular traps (NETs). These NETs do not mediate clearance of NTHI, which survives within NET structures by means of specific subpopulations of lipooligosaccharides on the bacterial surface that are determinants of biofilm formation in vitro. In this study, the ability of NTHI and NTHI components to initiate NET formation was examined using an in vitro model system. Both viable and nonviable NTHI strains were shown to promote NET formation, as did preparations of bacterial DNA, outer membrane proteins, and lipooligosaccharide (endotoxin). However, only endotoxin from a parental strain of NTHI exhibited equivalent potency in NET formation to that of NTHI. Additional studies showed that NTHI entrapped within NET structures is resistant to both extracellular killing within NETs and phagocytic killing by incoming neutrophils, due to oligosaccharide moieties within the lipooligosaccharides. Thus, we concluded that NTHI elicits NET formation by means of multiple pathogen-associated molecular patterns (most notably endotoxin) and is highly resistant to killing within NET structures. These data support the conclusion that, for NTHI, formation of NET structures may be a persistence determinant by providing a niche within the middle-ear chamber.

Antimicrobial susceptibility of Haemophilus parasuis and Histophilus somni from pigs and cattle in Denmark

DEFF Research Database (Denmark)

Aarestrup, Frank Møller; Seyfarth, Anne Mette; Angen, Øystein

2004-01-01

A total of 52 Haemophilus parasuis and 80 Histophilus somni isolates were tested for antimicrobial susceptibility by MIC-determinations. None of the isolates were resistant to ampicillin, ceftiofur, ciprofloxacin, erythromycin, florphenicol, penicillin, spectinomycin, tetracycline, tiamulin......, or tilmicosin. Two H. parasuis isolates were resistant to trimethoprim + sulfamethoxazole. Six H. parasuis isolates had reduced susceptibility (0.06-0.5 mug/ml) to ciprofloxacin and 10 reduced susceptibility to TMP + sulfamethoxazole (1-2 mug/ml). This study showed that Danish isolates of H. parasuis and H...

The molecular changing mechanism of Ampicillin-Sulbactam resistant Staphylococcus aureus towards Methicillin resistant Staphylococcus aureus

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Mieke Hemiawati Satari

2005-12-01

Full Text Available The aim of this study was to determine the molecular changing of S.aureus, which is resistant to Ampicillin-Sulbactam and then become resistant to Methicillin as a result of improper dosage. The study was conducted by isolating Ampicillin-Sulbactam resistant and Methicillin Resistant S.aureus (MRSA, afterwards an amplification process was performed by PCR (Polymerase Chain Reaction. to isolate the betalactamase enzyme regulator and PBP 2a genes. The result of this research showed that there were a deletion of few amino acids from the regulator gene, and a suspicion that the DNA sequence had been substituted from PBP 2 gene into PBP 2a (gen mec. This process had formed MRSA.

Aislamiento de distintos serotipos de Haemophilus influenzae en muestras profundas de pacientes pediátricos Isolation of Haemophilus influenzae serotypes from sterile sites in sick children

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B.M. Gatti

2004-03-01

Full Text Available Haemophilus influenzae (Hi es responsable de diversas enfermedades humanas como sepsis, meningitis, celulitis y osteoartritis. En este trabajo se investigó la recuperación de distintos serotipos de Hi en muestras profundas de pacientes pediátricos. Se estudiaron 179 aislamientos de 146 niños durante el periodo 1996-2002 en el Laboratorio de Microbiología del Hospital de Niños Superiora Sor María Ludovica, Argentina. La distribución de los serotipos fue la siguiente: 1 a, 112 b, 1 c,1 d, 4 e, 3 f y 24 no tipificables. A partir del establecimiento de la estrategia de vacunación universal anti Hi b en 1998 se observa una disminución notable del serotipo b y un aumento relativo de otros y no tipificables.Haemophilus influenzae (Hi is the causative agent of several human diseases such as sepsis, meningitis, celulitis, and osteoarthritis. We investigated the isolation of Hi serotypes from sterile sites in sick children. One hundred and seventy nine strains from 146 patients were studied, period 1996-2002, at the Microbiology Laboratory, Hospital de Niños Superiora Sor María Ludovica, Argentina. The serotype distribution was:1 a, 112 b,1 c,1 d, 4 e, 3 f y 24 no typable. Since the beginning of universal Hi b vaccination in 1998, we have observed the fast decrease of serotype b and a relative increase of other serotypes.

Molecular surveillance of true nontypeable Haemophilus influenzae: an evaluation of PCR screening assays.

Science.gov (United States)

Binks, Michael J; Temple, Beth; Kirkham, Lea-Ann; Wiertsema, Selma P; Dunne, Eileen M; Richmond, Peter C; Marsh, Robyn L; Leach, Amanda J; Smith-Vaughan, Heidi C

2012-01-01

Unambiguous identification of nontypeable Haemophilus influenzae (NTHi) is not possible by conventional microbiology. Molecular characterisation of phenotypically defined NTHi isolates suggests that up to 40% are Haemophilus haemolyticus (Hh); however, the genetic similarity of NTHi and Hh limits the power of simple molecular techniques such as PCR for species discrimination. Here we assess the ability of previously published and novel PCR-based assays to identify true NTHi. Sixty phenotypic NTHi isolates, classified by a dual 16S rRNA gene PCR algorithm as NTHi (n = 22), Hh (n = 27) or equivocal (n = 11), were further characterised by sequencing of the 16S rRNA and recA genes then interrogated by PCR-based assays targeting the omp P2, omp P6, lgtC, hpd, 16S rRNA, fucK and iga genes. The sequencing data and PCR results were used to define NTHi for this study. Two hpd real time PCR assays (hpd#1 and hpd#3) and the conventional iga PCR assay were equally efficient at differentiating study-defined NTHi from Hh, each with a receiver operator characteristic curve area of 0.90 [0.83; 0.98]. The hpd#1 and hpd#3 assays were completely specific against a panel of common respiratory bacteria, unlike the iga PCR, and the hpd#3 assay was able to detect below 10 copies per reaction. Our data suggest an evolutionary continuum between NTHi and Hh and therefore no single gene target could completely differentiate NTHi from Hh. The hpd#3 real time PCR assay proved to be the superior method for discrimination of NTHi from closely related Haemophilus species with the added potential for quantification of H. influenzae directly from specimens. We suggest the hpd#3 assay would be suitable for routine NTHi surveillance and to assess the impact of antibiotics and vaccines, on H. influenzae carriage rates, carriage density, and disease.

Molecular surveillance of true nontypeable Haemophilus influenzae: an evaluation of PCR screening assays.

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Michael J Binks

Full Text Available BACKGROUND: Unambiguous identification of nontypeable Haemophilus influenzae (NTHi is not possible by conventional microbiology. Molecular characterisation of phenotypically defined NTHi isolates suggests that up to 40% are Haemophilus haemolyticus (Hh; however, the genetic similarity of NTHi and Hh limits the power of simple molecular techniques such as PCR for species discrimination. METHODOLOGY/PRINCIPAL FINDINGS: Here we assess the ability of previously published and novel PCR-based assays to identify true NTHi. Sixty phenotypic NTHi isolates, classified by a dual 16S rRNA gene PCR algorithm as NTHi (n = 22, Hh (n = 27 or equivocal (n = 11, were further characterised by sequencing of the 16S rRNA and recA genes then interrogated by PCR-based assays targeting the omp P2, omp P6, lgtC, hpd, 16S rRNA, fucK and iga genes. The sequencing data and PCR results were used to define NTHi for this study. Two hpd real time PCR assays (hpd#1 and hpd#3 and the conventional iga PCR assay were equally efficient at differentiating study-defined NTHi from Hh, each with a receiver operator characteristic curve area of 0.90 [0.83; 0.98]. The hpd#1 and hpd#3 assays were completely specific against a panel of common respiratory bacteria, unlike the iga PCR, and the hpd#3 assay was able to detect below 10 copies per reaction. CONCLUSIONS/SIGNIFICANCE: Our data suggest an evolutionary continuum between NTHi and Hh and therefore no single gene target could completely differentiate NTHi from Hh. The hpd#3 real time PCR assay proved to be the superior method for discrimination of NTHi from closely related Haemophilus species with the added potential for quantification of H. influenzae directly from specimens. We suggest the hpd#3 assay would be suitable for routine NTHi surveillance and to assess the impact of antibiotics and vaccines, on H. influenzae carriage rates, carriage density, and disease.

Antibody response to Haemophilus influenzae type b capsular polysaccharide conjugated to tetanus toxoid in preterm infants

DEFF Research Database (Denmark)

Kristensen, Kim; Gyhrs, A; Lausen, B

1996-01-01

OBJECTIVE: To evaluate the antibody response to a Haemophilus influenzae type b capsular polysaccharide (HibCP) tetanus toxoid (TT) conjugate vaccine (HibCP-TT) in preterm infants. SUBJECTS: Thirty-five healthy preterm infants with gestational ages (GA) from 27 to 36 weeks and birth weights from...

Radioimmunoassay of capsular polysaccaride antigens of groups A and C meningococci and Haemophilus influenza type b in cerebrospinal fluid

International Nuclear Information System (INIS)

Kaeyhty, H.; Maekelae, P.H.; Ruoslahti, E.

1977-01-01

Sensitive radioimmunoassays capable of measuring 0.5 ng/ml of the Haemophilus influenza type b polysaccharide and 2 ng/ml of the groups A and C meningococcal polysaccharides were developed and used to detect these substances in cerebrospinal fluid (CSF). Polysaccharide of the causative agent was detected in the CSF of 14 out of 15 patients with Haemophilus influenza type b meningitis, in 18 out of 23 patients with group A, and in two out of four patients with group C meningococcal meningitis. In some cases the antigen could be detected even after three days of antibacterial treatment. No false positive reactions were seen. The assay procedure could be shortened to approximately three hours. These assays could be useful in routine diagnostic work and epidemiological investigations. (author)

Meningite por Haemophilus influenzae tipo b em cidades do estado do Paraná, Brasil Haemophilus influenzae type b meningitis in the state of Paraná, Brazil

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Nádia S. Takemura

2001-10-01

Full Text Available OBJETIVO: no segundo semestre de 1996, os municípios de Londrina e Curitiba (Paraná iniciaram a vacinação contra Haemophilus influenzae b (Hib, aproximadamente trinta meses antes de sua introdução no Programa Nacional de Imunização. O presente trabalho objetivou avaliar a incidência da meningite por Hib, entre crianças, em Londrina, Curitiba e nos demais municípios do estado do Paraná, antes e após a introdução da vacina nessas duas cidades. MÉTODOS: foi realizado um estudo observacional retrospectivo de todos os casos de meningite por Hib, entre menores de 5 anos, diagnosticados pelo sistema de vigilância epidemiológica de Londrina e pela Secretaria de Estado da Saúde do Paraná, de 1992 a 1999. Taxas de incidência da meningite por Hib foram calculadas por 100.000 menores de cinco anos. RESULTADOS: comparando com o período anterior à vacinação, houve redução importante do coeficiente de incidência da meningite por Hib em Londrina, passando de 23,91, em 1996, para 2,79 por 100.000 menores de cinco anos, em 1999. Redução semelhante foi observada em Curitiba, enquanto nos demais municípios do Paraná, que não dispunham da vacina até meados de 1999, o coeficiente se manteve praticamente inalterado. CONCLUSÃO: a vacinação contra Hib foi efetiva na redução da incidência da meningite entre menores de cinco anos em Londrina e Curitiba. Para a manutenção dessa baixa incidência devem ser garantidas adequada cobertura vacinal e boa qualidade do serviço de vigilância epidemiológica.OBJECTIVE: during the second half of 1996, the municipalities of Londrina and Curitiba (State of Paraná, Brazil included Haemophilus influenzae type b (Hib vaccine into their routine vaccination regimen, approximately 30 months before its introduction into the National Immunization Program. The present study aimed at verifying the incidence of meningitis caused by Hib among children in Londrina, Curitiba, and in the remaining

Transformation of natural genetic variation into Haemophilus influenzae genomes.

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Joshua Chang Mell

2011-07-01

Full Text Available Many bacteria are able to efficiently bind and take up double-stranded DNA fragments, and the resulting natural transformation shapes bacterial genomes, transmits antibiotic resistance, and allows escape from immune surveillance. The genomes of many competent pathogens show evidence of extensive historical recombination between lineages, but the actual recombination events have not been well characterized. We used DNA from a clinical isolate of Haemophilus influenzae to transform competent cells of a laboratory strain. To identify which of the ~40,000 polymorphic differences had recombined into the genomes of four transformed clones, their genomes and their donor and recipient parents were deep sequenced to high coverage. Each clone was found to contain ~1000 donor polymorphisms in 3-6 contiguous runs (8.1±4.5 kb in length that collectively comprised ~1-3% of each transformed chromosome. Seven donor-specific insertions and deletions were also acquired as parts of larger donor segments, but the presence of other structural variation flanking 12 of 32 recombination breakpoints suggested that these often disrupt the progress of recombination events. This is the first genome-wide analysis of chromosomes directly transformed with DNA from a divergent genotype, connecting experimental studies of transformation with the high levels of natural genetic variation found in isolates of the same species.

Recombinant C-terminal 311 amino acids of HapS adhesin as a vaccine candidate for nontypeable Haemophilus influenzae: A study on immunoreactivity in Balb/C mouse.

Science.gov (United States)

Tabatabaee Bafroee, Akram Sadat; Siadat, Seyed Davar; Mousavi, Seyed Fazlollah; Aghasadeghi, Mohammad Reza; Khorsand, Hashem; Nejati, Mehdi; Sadat, Seyed Mehdi; Mahdavi, Mehdi

2016-09-01

Hap, an auto-transporter protein, is an antigenically conserved adhesion protein which is present on both typeable and nontypeable Haemophilus influenzae. This protein has central role in bacterial attachment to respiratory tract epithelial cells. A 1000bp C-terminal fragment of Hap passenger domain (HapS) from nontypeable Haemophilus influenzae was cloned into a prokaryotic expression vector, pET-24a. BALB/c mice were immunized subcutaneously with purified rC-HapS. Serum IgG responses to purified rC-HapS, serum IgG subclasses were determined by ELISA and functional activity of antibodies was examined by Serum Bactericidal Assay. The output of rC-HapS was approximately 62% of the total bacterial proteins. Serum IgG responses were significantly increased in immunized group with rC-HapS mixed with Freund's adjuvant in comparison with control groups. Analysis of the serum IgG subclasses showed that the IgG1 subclass was predominant after subcutaneous immunization in BALB/c mice (IgG2a/IgG1 HapS immunized animals were strongly bactericidal against nontypeable Haemophilus influenzae. These results suggest that rC-HapS may be a potential vaccine candidate for nontypeable Haemophilus influenzae. Copyright © 2016 Elsevier Ltd. All rights reserved.

Airway inflammation in nonobstructive and obstructive chronic bronchitis with chronic haemophilus influenzae airway infection. Comparison with noninfected patients with chronic obstructive pulmonary disease

NARCIS (Netherlands)

Bresser, P.; Out, T. A.; van Alphen, L.; Jansen, H. M.; Lutter, R.

2000-01-01

Nonencapsulated Haemophilus influenzae often causes chronic infections of the lower respiratory tract in both nonobstructive and obstructive chronic bronchitis. We assessed airway inflammation in clinically stable, chronically H. influenzae-infected patients with nonobstructive (CB-HI, n = 10) and

Haemophilus influenzae: an underrated cause of vulvovaginitis in young girls.

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Cox, R A

1997-01-01

AIMS: To establish the common pathogens associated with infective vulvovaginitis in young girls in the local population and to determine current management of this condition. METHODS: A prospective laboratory based survey was carried out over 19 months. A questionnaire was then sent to local general practitioners and hospital doctors. RESULTS: One hundred and six swabs were received during the study period of which 43 (40.5%) yielded organisms recognised as causes of vulvovaginitis. The most common pathogen was group A beta haemolytic streptococcus (19), with Haemophilus influenzae the second most common (11). Candida was isolated on nine occasions. The users' questionnaire had an overall response rate of 52%. Forty one per cent of respondents nominated candida as the most common cause of this condition. Forty six per cent were aware that beta haemolytic streptococci caused juvenile vulvovaginitis, but only four (3.6%) knew that H influenzae was a possible pathogen. The most popular agent for empirical treatment of vulvovaginitis was topical clotrimazole cream, although 24 respondents (22%) prescribed antibiotics that are active against both group A beta haemolytic streptococci and H influenzae. CONCLUSIONS: Although H influenzae is the second most common infective cause of juvenile vulvovaginitis in the local population, most doctors managing these patients were unaware of its importance and may not be prescribing appropriate empirical treatment. Images PMID:9389978

Rapid Differentiation of Haemophilus influenzae and Haemophilus haemolyticus by Use of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry with ClinProTools Mass Spectrum Analysis.

Science.gov (United States)

Chen, Jonathan H K; Cheng, Vincent C C; Wong, Chun-Pong; Wong, Sally C Y; Yam, Wing-Cheong; Yuen, Kwok-Yung

2017-09-01

Haemophilus influenzae is associated with severe invasive disease, while Haemophilus haemolyticus is considered part of the commensal flora in the human respiratory tract. Although the addition of a custom mass spectrum library into the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system could improve identification of these two species, the establishment of such a custom database is technically complicated and requires a large amount of resources, which most clinical laboratories cannot afford. In this study, we developed a mass spectrum analysis model with 7 mass peak biomarkers for the identification of H. influenzae and H. haemolyticus using the ClinProTools software. We evaluated the diagnostic performance of this model using 408 H. influenzae and H. haemolyticus isolates from clinical respiratory specimens from 363 hospitalized patients and compared the identification results with those obtained with the Bruker IVD MALDI Biotyper. The IVD MALDI Biotyper identified only 86.9% of H. influenzae (311/358) and 98.0% of H. haemolyticus (49/50) clinical isolates to the species level. In comparison, the ClinProTools mass spectrum model could identify 100% of H. influenzae (358/358) and H. haemolyticus (50/50) clinical strains to the species level and significantly improved the species identification rate (McNemar's test, P mass spectrometry to handle closely related bacterial species when the proprietary spectrum library failed. This approach should be useful for the differentiation of other closely related bacterial species. Copyright © 2017 American Society for Microbiology.

Nontypeable Haemophilus influenzae biofilms: role in chronic airway infections

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W Edward Swords

2012-07-01

Full Text Available Like many pathogens inhabiting mucosal surfaces, nontypeable Haemophilus influenzae (NTHi forms multicellular biofilm communities both in vitro and in various infection models. In the past 15 years much has been learned about determinants of biofilm formation by this organism and potential roles in bacterial virulence, especially in the context of chronic and recurrent infections. However, this concept has not been without some degree of controversy, and in the past some have expressed doubts about the relevance of NTHi biofilms to disease. In this review, I will summarize the present information on the composition and potential role(s of NTHi biofilms in different clinical contexts, as well as highlight potential areas for future work.

Nontypeable Haemophilus influenzae biofilms: role in chronic airway infections.

Science.gov (United States)

Swords, W Edward

2012-01-01

Like many pathogens inhabiting mucosal surfaces, nontypeable Haemophilus influenzae (NTHi) forms multicellular biofilm communities both in vitro and in various infection models. In the past 15 years much has been learned about determinants of biofilm formation by this organism and potential roles in bacterial virulence, especially in the context of chronic and recurrent infections. However, this concept has not been without some degree of controversy, and in the past some have expressed doubts about the relevance of NTHi biofilms to disease. In this review, I will summarize the present information on the composition and potential role(s) of NTHi biofilms in different clinical contexts, as well as highlight potential areas for future work.

Structure of the N-terminal region of Haemophilus Influenzae HI0017: Implications for function

International Nuclear Information System (INIS)

Yu Liping; Mack, Jamey; Hajduk, Phil; Fesik, Stephen W.

2001-01-01

Haemophilus influenzae is a gram-negative pathogen that causes infections ranging from asymptomatic colonization of the human upper respiratory tract to serious invasive diseases such as meningitis. Although the genome of Haemophilus influenzae has been completely sequenced, the structure and function of many of these proteins are unknown. HI0017 is one of these uncharacterized proteins. Here we describe the three-dimensional solution structure of the N-terminal portion of HI0017 as determined by NMR spectroscopy. The structure consists of a five-stranded antiparallel β-sheet and two short α-helices. It is similar to the C-terminal domain of Diphtheria toxin repressor (DtxR). The C-terminal portion of HI0017 has an amino acid sequence that closely resembles pyruvate formate-lyase - an enzyme that converts pyruvate and CoA into acetyl-CoA and formate by a radical mechanism. Based on structural and sequence comparisons, we propose that the C-terminus of HI0017 functions as an enzyme with a glycyl radical mechanism, while the N-terminus participates in protein/protein interactions involving an activase (iron-sulfur protein) and/or the substrate

Structure of the N-terminal region of Haemophilus Influenzae HI0017: Implications for function

Energy Technology Data Exchange (ETDEWEB)

Yu Liping; Mack, Jamey; Hajduk, Phil; Fesik, Stephen W. [Abbott Laboratories, Pharmaceutical Discovery Division, D46Y, AP10/LL (United States)

2001-06-15

Haemophilus influenzae is a gram-negative pathogen that causes infections ranging from asymptomatic colonization of the human upper respiratory tract to serious invasive diseases such as meningitis. Although the genome of Haemophilus influenzae has been completely sequenced, the structure and function of many of these proteins are unknown. HI0017 is one of these uncharacterized proteins. Here we describe the three-dimensional solution structure of the N-terminal portion of HI0017 as determined by NMR spectroscopy. The structure consists of a five-stranded antiparallel {beta}-sheet and two short {alpha}-helices. It is similar to the C-terminal domain of Diphtheria toxin repressor (DtxR). The C-terminal portion of HI0017 has an amino acid sequence that closely resembles pyruvate formate-lyase - an enzyme that converts pyruvate and CoA into acetyl-CoA and formate by a radical mechanism. Based on structural and sequence comparisons, we propose that the C-terminus of HI0017 functions as an enzyme with a glycyl radical mechanism, while the N-terminus participates in protein/protein interactions involving an activase (iron-sulfur protein) and/or the substrate.

Simple test of synergy between ampicillin and vancomycin for resistant strains of Enterococcus faecium.

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Green, M; Barbadora, K; Wadowsky, R M

1994-11-01

The combination of ampicillin and vancomycin kills some but not all strains of ampicillin- and vancomycin-resistant Enterococcus faecium. We compared a simple test for synergy utilizing a commercially available microdilution susceptibility system with time-kill studies and determined acceptable breakpoints for this test for 20 strains of ampicillin- and vancomycin-resistant E. faecium. The combination of ampicillin and vancomycin was tested for synergy by time-kill, broth macrodilution, and broth microdilution procedures. Repeat testing of isolates by macro- and microdilution synergy methods yielded MICs that were within one twofold dilution of each other for both intra- and intertest comparisons. Synergy was always detected by time-kill studies when the MIC of ampicillin in the combination synergy screen was 16 micrograms/ml in the combination microdilution synergy screen. The determination of the synergy by the broth microdilution procedure appears to be simple, convenient, and accurate.

Clinical characteristics of Haemophilus influenzae meningitis in Denmark in the post-vaccination era

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Pedersen, T.I.; Howitz, Michael Frantz; Andersen, Christian Østergaard

2010-01-01

P>The introduction of Haemophilus influenzae type b (Hib) vaccine into the Danish childhood vaccination programme in 1993 may have influenced the epidemiology of H. influenzae meningitis (i.e. increasing frequency of other non-vaccine types; presentation in other age groups). Based on nationwide...... infected with Hib, two cases (13%) were identified as true vaccine failures. Six patients (9%) died; one premature infant infected with serotype f and five adults (age 83-96 years) with non-typeable H. influenzae. Hearing loss was reported in 16% of the surviving children and in 10% of the surviving adults....... The presence of a lung focus was an independent prognostic factor for an unfavourable outcome (p 0.03). In conclusion, meningitis caused by Hib has been infrequent in Denmark after introduction of the Hib vaccine in the childhood vaccination programme, and no increase in meningitis cases due to non-b type H...

Non-Type b Haemophilus influenzae Invasive Infections in North Dakota and South Dakota, 2013-2015.

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Antony, Stephanie; Kaushik, Ashlesha; Mauriello, Clifford; Chatterjee, Archana

2017-09-01

Reports of children with non-type b Haemophilus influenzae infection in the United States in recent years have been limited. Here, we report the spectrum and severity of disease associated with invasive non-type b H influenzae infection in 17 patients at 2 tertiary-care children's hospitals over a 2-year period. Meningitis was the most common diagnosis. The majority of the patients had neurologic sequelae, and 1 patient died. The high proportions of hospitalization, intensive care utilization, and neurologic complications reveal that non-type b H influenzae infection was associated with significant morbidity in this pediatric population. © The Author 2016. Published by Oxford University Press on behalf of the Pediatric Infectious Diseases Society. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

'Haemophilus quentini' in the urethra of men complaining of urethritis symptoms.

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Horie, Kengo; Ito, Shin; Hatazaki, Kyoko; Yasuda, Mitsuru; Nakano, Masahiro; Kawakami, Kyojiro; Fujita, Yasunori; Ito, Masafumi; Ezaki, Takayuki; Deguchi, Takashi

2018-01-01

We isolated a cryptic genospecies of Haemophilus influenzae referred to as 'Haemophilus quentini' in the urethra of 3 men complaining of urethritis symptoms. H. influenzae strains, which had been isolated from the urethra in 77 of 1518 men complaining of urethritis symptoms, identified by the conventional test, and stored, were re-cultured for this study. Sixty-seven strains surviving storage were screened by a PCR-based assay specific for the cryptic genital Haemophilus genospecies. Three strains (HI09003, HI11006, and HI14016) were screened by PCR and identified as 'H. quentini' by 16S rRNA sequencing. The men positive for HI09003 and HI11006 were diagnosed as having non-chlamydial non-gonococcal urethritis (NGU), and their demographic and clinical features were similar to those of NGU caused by other pathogens. The man positive for HI14016 was ultimately diagnosed as having condyloma acuminatum on the glans. The 3 strains of 'H. quentini' produced no β-lactamase and were susceptible to ampicillin and other antimicrobial agents, including cephalosporins, fluoroquinolones, tetracyclines, and macrolides, recommended for treatment for urethritis. 'H. quentini' would be an uncommon pathogen in men with urogenital infections. Based on the clinical features of the two patients with 'H. quentini'-positive NGU, it would be difficult to predict the presence of 'H. quentini' in the urethra. The 3 strains of 'H. quentini' were susceptible to a variety of antimicrobial agents. Further accumulation of data regarding 'H. quentini' infections is needed to characterize the pathogenic roles of this genospecies in urogenital infections and to establish appropriate management of 'H. quentini' infections. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Towards a sustainable, quality and affordable Haemophilus influenzae type b vaccine for every child in the world

NARCIS (Netherlands)

Hamidi, A.

2016-01-01

Haemophilus influenzae type b (Hib) conjugate vaccine is a safe and effective vaccine that can prevent meningitis and pneumonia caused by Hib disease. Hib vaccine is recommended for all children under 5 years. Despite the availability of safe and effective Hib vaccines since early 1987, Gambia was

Peroxiredoxin-glutaredoxin and catalase promote resistance of nontypeable Haemophilus influenzae 86-028NP to oxidants and survival within neutrophil extracellular traps.

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Juneau, Richard A; Pang, Bing; Armbruster, Chelsie E; Murrah, Kyle A; Perez, Antonia C; Swords, W Edward

2015-01-01

Nontypeable Haemophilus influenzae (NTHI) is a common commensal and opportunistic pathogen of the human airways. For example, NTHI is a leading cause of otitis media and is the most common cause of airway infections associated with chronic obstructive pulmonary disease (COPD). These infections are often chronic/recurrent in nature and involve bacterial persistence within biofilm communities that are highly resistant to host clearance. Our previous work has shown that NTHI within biofilms has increased expression of factors associated with oxidative stress responses. The goal of this study was to define the roles of catalase (encoded by hktE) and a bifunctional peroxiredoxin-glutaredoxin (encoded by pdgX) in resistance of NTHI to oxidants and persistence in vivo. Isogenic NTHI strain 86-028NP mutants lacking hktE and pdgX had increased susceptibility to peroxide. Moreover, these strains had persistence defects in the chinchilla infection model for otitis media, as well as in a murine model for COPD. Additional work showed that pdgX and hktE were important determinants of NTHI survival within neutrophil extracellular traps (NETs), which we have shown to be an integral part of NTHI biofilms in vivo. Based on these data, we conclude that catalase and peroxiredoxin-glutaredoxin are determinants of bacterial persistence during chronic/recurrent NTHI infections that promote bacterial survival within NETs. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Metabolic versatility in Haemophilus influenzae: a metabolomic and genomic analysis

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Dk Seti Maimonah Pg eOthman

2014-03-01

Full Text Available Haemophilus influenzae is a host adapted human pathogen known to contribute to a variety of acute and chronic diseases of the upper and lower respiratory tract as well as the middle ear. At the sites of infection as well as during growth as a commensal the environmental conditions encountered by H. influenzae will vary significantly, especially in terms of oxygen availability, however, the mechanisms by which the bacteria can adapt their metabolism to cope with such changes have not been studied in detail. Using targeted metabolomics the spectrum of metabolites produced during growth of H. influenzae on glucose in RPMI-based medium was found to change from acetate as the main product during aerobic growth to formate as the major product during anaerobic growth. This is likely caused by a switch in the major pyruvate degrading route. Neither lactate nor succinate or fumarate were major products of H. influenzae growth under any condition studied Gene expression studies and enzyme activity data revealed that despite an identical genetic makeup and very similar metabolite production profiles, H. influenzae strain Rd appeared to favour glucose degradation via the PPP, while strain 2019, a clinical isolate, showed higher expression of enzymes involved in glycolysis. Components of the respiratory chain were most highly expressed during microaerophilic and anaerobic growth in both strains, but again clear differences existed in the expression of genes associated e.g. with NADH oxidation, nitrate and nitrite reduction in the two strains studied.Together our results indicate that H. influenzae uses a specialized type of metabolism that could be termed ‘respiration assisted fermentation’ where the respiratory chain likely serves to alleviate redox imbalances caused by incomplete glucose oxidation, and at the same time provides a means of converting a variety of compounds including nitrite and nitrate that arise as part of the host defence mechanisms.

Novel carbapenem antibiotics for parenteral and oral applications: in vitro and in vivo activities of 2-aryl carbapenems and their pharmacokinetics in laboratory animals.

Science.gov (United States)

Fujimoto, Koichi; Takemoto, Koji; Hatano, Kazuo; Nakai, Toru; Terashita, Shigeyuki; Matsumoto, Masahiro; Eriguchi, Yoshiro; Eguchi, Ken; Shimizudani, Takeshi; Sato, Kimihiko; Kanazawa, Katsunori; Sunagawa, Makoto; Ueda, Yutaka

2013-02-01

SM-295291 and SM-369926 are new parenteral 2-aryl carbapenems with strong activity against major causative pathogens of community-acquired infections such as methicillin-susceptible Staphylococcus aureus, Streptococcus pneumoniae (including penicillin-resistant strains), Streptococcus pyogenes, Enterococcus faecalis, Klebsiella pneumoniae, Moraxella catarrhalis, Haemophilus influenzae (including β-lactamase-negative ampicillin-resistant strains), and Neisseria gonorrhoeae (including ciprofloxacin-resistant strains), with MIC(90)s of ≤ 1 μg/ml. Unlike tebipenem (MIC(50), 8 μg/ml), SM-295291 and SM-369926 had no activity against hospital pathogens such as Pseudomonas aeruginosa (MIC(50), ≥ 128 μg/ml). The bactericidal activities of SM-295291 and SM-369926 against penicillin-resistant S. pneumoniae and β-lactamase-negative ampicillin-resistant H. influenzae were equal or superior to that of tebipenem and greater than that of cefditoren. The therapeutic efficacies of intravenous administrations of SM-295291 and SM-369926 against experimentally induced infections in mice caused by penicillin-resistant S. pneumoniae and β-lactamase-negative ampicillin-resistant H. influenzae were equal or superior to that of tebipenem and greater than that of cefditoren, respectively, reflecting their in vitro activities. SM-295291 and SM-369926 showed intravenous pharmacokinetics similar to those of meropenem in terms of half-life in monkeys (0.4 h) and were stable against human dehydropeptidase I. SM-368589 and SM-375769, which are medoxomil esters of SM-295291 and SM-369926, respectively, showed good oral bioavailability in rats, dogs, and monkeys (4.2 to 62.3%). Thus, 2-aryl carbapenems are promising candidates that show an ideal broad spectrum for the treatment of community-acquired infections, including infections caused by penicillin-resistant S. pneumoniae and β-lactamase-negative ampicillin-resistant H. influenzae, have low selective pressure on antipseudomonal

Aspectos epidemiológicos da infecção por Haemophilus influenzae tipo b Epidemiologic aspects of Haemophilus influenzae type b infection

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Maria Angela Loguercio Bouskela

2000-05-01

Full Text Available O objetivo do presente trabalho foi revisar o papel do Haemophilus influenzae tipo b (Hib como um dos patógenos mais importantes implicados em doenças infecciosas invasivas, especialmente nos 2 primeiros anos de vida. Nos países em desenvolvimento, o H. Influenzae chega a causar 30% dos casos de pneumonia com cultura positiva e de 20 a 60% dos casos de meningite bacteriana. No presente estudo, dados epidemiológicos do Brasil foram comparados com dados internacionais obtidos em bancos de dados (Medline, 1966 a 1995; LILACS, 1982 a 1995; Thesis databank, 1980 a 1995; e Dissertation abstracts, 1988 a 1994. Analisámos o coeficiente de incidência do Hib no Brasil por estado e por faixa etária, com estratificação inclusive para o 1° ano de vida. A meningite foi utilizada como marcador do coeficiente de incidência devido às dificuldades para obter material adequado para a identificação do microrganismo nos outros quadros, como pneumonia, osteomielite, epiglotite ou endocardite. Nossa análise revelou que os dados nacionais mascaram a incidência e a letalidade regionais do H. influenzae: por exemplo, em 1991, a incidência no Brasil foi de 18,4 em 100 000 crianças menores de 1 ano; no mesmo período, a incidência no Distrito Federal foi de 175 em 100 000 crianças entre 4 e 6 meses. Além disso, a letalidade na região Norte foi de 35% em 1987, contra 22% para o Brasil como um todo. Nosso estudo abre a discussão sobre aspectos epidemiológicos relevantes das infecções por Hib e sobre o custo-benefício da profilaxia e vacinação nas faixas etárias de maior risco.This paper reviews the role of Haemophilus influenzae type b (Hib as one of the most important pathogens causing invasive infectious diseases, especially in the first 2 years of life. In developing countries H. influenzae is responsible for 30% of all pneumonia cases with positive cultures and for 20% to 60% of all bacterial meningitis cases. In this study we compared

Haemophilus influenzae vulvovaginitis associated with rhinitis caused by the same clone in a prepubertal girl.

Science.gov (United States)

Chen, Xiao; Chen, Lifeng; Zeng, Wenjie; Zhao, Xiaofeng

2017-06-01

Vulvovaginitis caused by upper respiratory flora is generally considered to be the most common gynecological problem in prepubertal girls. To date, however, no direct evidence has been obtained for the underlying mechanism of transmission. This report describes a case of non-capsulate Haemophilus influenzae vulvovaginitis in a 6-year-old girl with a history of foreign bodies (cotton wool) in her vagina. Moreover, this girl had recurrent rhinitis for approximately 3 years. On Pulsed Field Gel Electrophoresis (PFGE) analysis the H. influenzae strain isolated from vaginal secretions and the H. influenzae strain isolated from nasal secretions were derived from the same clone. The patient was successfully treated with appropriate antibiotics. The present case might provide the first direct evidence of the nose-hand-vagina method of transmission. © 2017 Japan Society of Obstetrics and Gynecology.

Haemophilus influenzae pneumonia in human immunodeficiency virus-infected patients. The Grupo Andaluz para el Estudio de las Enfermedades Infecciosas.

Science.gov (United States)

Cordero, E; Pachón, J; Rivero, A; Girón, J A; Gómez-Mateos, J; Merino, M D; Torres-Tortosa, M; González-Serrano, M; Aliaga, L; Collado, A; Hernández-Quero, J; Barrera, A; Nuño, E

2000-03-01

Although Haemophilus influenzae is a common etiologic agent of pneumonia in patients infected with human immunodeficiency virus (HIV), the characteristics of this pneumonia have not been adequately assessed. We have prospectively studied features of H. influenzae pneumonia in 26 consecutive HIV-infected inpatients. Most of these patients were severely immunosuppressed; 73.1% had a CD4+ cell count caused by H. influenzae affects mainly patients with advanced HIV disease, and since its clinical and radiological features may be diverse, this etiology should be considered when pneumonia occurs in patients with advanced HIV infection. The mortality rate associated with H. influenzae pneumonia is not higher than that occurring in the general population.

Identification of a group of Haemophilus influenzae penicillin-binding proteins that may have complementary physiological roles

International Nuclear Information System (INIS)

Malouin, F.; Parr, T.R. Jr.; Bryan, L.E.

1990-01-01

[35S]penicillin bound to different Haemophilus influenzae proteins in assays performed at 20, 37, or 42 degrees C. Penicillin-binding proteins 3a, 3b, 4, and 4' formed a group characterized by their affinity for moxalactam, cefotaxime, and piperacillin. Penicillin-binding protein 4' showed specific properties that may reflect its complementary role in septation

Ampicillin radioprotector effect

International Nuclear Information System (INIS)

Padron, E.; Fernandez-Larrea, O.; Rios, F.

1991-01-01

This paper deals with the effect of ampicillin during irradiation and recovery of the Bacillus licheniformis RI 75-1 stump with a savage genotype of recovery exposed to ionizing radiations and treated with gamma quantums. Previous research enabled to prove that in Bacillus licheniformis spores suspensions, irradiated of vegetative cells in ampicillin at D-1--0- dose, causes significative lethal increases. In this paper, The irradiation of vegetative cells in presence of 5 mcg/ml of ampicillin increases the viability at doses above 1 kGy. the survival rates was raised when vegetative cells of Bacillus lincheniformis were irradiated at 1.2 kGy and recovered in a nutrient environment during 2 hours (LHR) in presence of ampicillin. Twenty-two stumps of Bacillus licheniformis obtained through different mutagenic treatments were studied in relation to the resistance of ampicillim and at 3 Kgy gamma quantums and a direct correlation between these two was stablished. Previous treatment with ampicillin of the vegetative cells from the Bacillus licheniformis increased the number of resistants to gamma quantums. There was no information about this phenomenom in literature consulted

Dogs are a reservoir of ampicillin-resistant Enterococcus faecium lineages associated with human infections

DEFF Research Database (Denmark)

Damborg, Peter Panduro; Top, Janetta; Hendrickx, Antoni P.A.

2009-01-01

Ampicillin resistance is a marker for hospital-associated Enterococcus faecium. Feces from 208 dogs were selectively screened for the occurrence of ampicillin-resistant E. faecium (AREF). AREF was detected in 42 (23%) of 183 dogs screened in a cross-sectional study in the United Kingdom and in 19...

Inhibitory effect of 1,2,4-triazole-ciprofloxacin hybrids on Haemophilus parainfluenzae and Haemophilus influenzae biofilm formation in vitro under stationary conditions.

Science.gov (United States)

Kosikowska, Urszula; Andrzejczuk, Sylwia; Plech, Tomasz; Malm, Anna

2016-10-01

Haemophilus parainfluenzae and Haemophilus influenzae, upper respiratory tract microbiota representatives, are able to colonize natural and artificial surfaces as biofilm. The aim of the present study was to assay the effect of ten 1,2,4-triazole-ciprofloxacin hybrids on planktonic or biofilm-forming haemophili cells in vitro under stationary conditions on the basis of MICs (minimal inhibitory concentrations) and MBICs (minimal biofilm inhibitory concentrations). In addition, anti-adhesive properties of these compounds were examined. The reference strains of H. parainfluenzae and H. influenzae were included. The broth microdilution microtiter plate (MTP) method with twofold dilution of the compounds, or ciprofloxacin (reference agent) in 96-well polystyrene microplates, was used. The optical density (OD) reading was made spectrophotometrically at a wavelength of 570 nm (OD570) both to measure bacterial growth and to detect biofilm-forming cells under the same conditions with 0.1% crystal violet. The following values of parameters were estimated for 1,2,4-triazole-ciprofloxacin hybrids - MIC = 0.03-15.63 mg/L, MBIC = 0.03-15.63 mg/L, MBIC/MIC = 0.125-8, depending on the compound, and for ciprofloxacin - MIC = 0.03-0.06 mg/L, MBIC = 0.03-0.12 mg/L, MBIC/MIC = 1-2. The observed strong anti-adhesive properties (95-100% inhibition) of the tested compounds were reversible during long-term incubation at subinhibitory concentrations. Thus, 1,2,4-triazole-ciprofloxacin hybrids may be considered as starting compounds for designing improved agents not only against planktonic but also against biofilm-forming Haemophilus spp. cells. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Structural Determinants of Autoproteolysis of the Haemophilus influenzae Hap Autotransporter▿

Science.gov (United States)

Kenjale, Roma; Meng, Guoyu; Fink, Doran L.; Juehne, Twyla; Ohashi, Tomoo; Erickson, Harold P.; Waksman, Gabriel; St. Geme, Joseph W.

2009-01-01

Haemophilus influenzae is a gram-negative bacterium that initiates infection by colonizing the upper respiratory tract. The H. influenzae Hap autotransporter protein mediates adherence, invasion, and microcolony formation in assays with respiratory epithelial cells and presumably facilitates colonization. The serine protease activity of Hap is associated with autoproteolytic cleavage and extracellular release of the HapS passenger domain, leaving the Hapβ C-terminal domain embedded in the outer membrane. Cleavage occurs most efficiently at the LN1036-37 peptide bond and to a lesser extent at three other sites. In this study, we utilized site-directed mutagenesis, homology modeling, and assays with a peptide library to characterize the structural determinants of Hap proteolytic activity and cleavage specificity. In addition, we used homology modeling to predict the S1, S2, and S4 subsite residues of the Hap substrate groove. Our results indicate that the P1 and P2 positions at the Hap cleavage sites are critical for cleavage, with leucine preferred over larger hydrophobic residues or other amino acids in these positions. The substrate groove is formed by L263 and N274 at the S1 subsite, R264 at the S2 subsite, and E265 at the S4 subsite. This information may facilitate design of approaches to block Hap activity and interfere with H. influenzae colonization. PMID:19687208

Influence of prevaccination immunity on the human B-lymphocyte response to a Haemophilus influenzae type b conjugate vaccine

DEFF Research Database (Denmark)

Barington, T; Kristensen, K; Henrichsen, J

1991-01-01

of Haemophilus influenzae type b capsular polysaccharide (PRP) and diphtheria toxoid (DT), and the response was related to the prevaccination levels of PRP and DT antibodies. Positive correlations were found between increases in plasma PRP (median, 32.0 micrograms/ml) and DT (1.14 IU/ml) antibodies and numbers...

[Isolation of Haemophilus influenzae serotypes from deep sites in sick children].

Science.gov (United States)

Gatti, B M; Ramirez Gronda, G A; Etchevarría, M; Vescina, C M; Varea, A M; González Ayala, S E

2004-01-01

Haemophilus influenzae (Hi) is the causative agent of several human diseases such as sepsis, meningitis, celulitis, and osteoarthritis. We investigated the isolation of Hi serotypes from sterile sites in sick children. One hundred and seventy nine strains from 146 patients were studied, period 1996-2002, at the Microbiology Laboratory, Hospital de Niños Superiora Sor María Ludovica, Argentina. The serotype distribution was:1 a, 112 b,1 c,1 d, 4 e, 3 f y 24 no typable. Since the beginning of universal Hi b vaccination in 1998, we have observed the fast decrease of serotype b and a relative increase of other serotypes.

Antimicrobial susceptibility of Pasteurella multocida and Haemophilus parasuis isolates associated with porcine pneumonia

Directory of Open Access Journals (Sweden)

Kateřina Nedbalcová

2013-01-01

Full Text Available Pasteurella multocida and Haemophilus parasuis pig isolates obtained in the Czech Republic were tested for their susceptibility against selected antimicrobial agents by broth microdilution method between 2008 and 2011. A low degree of resistance was observed for ampicillin, amoxicillin/clavulanic acid, ceftiofur, tulathromycin, tilmicosin, florfenicol and enrofloxacin in 20 (6.0%, 15 (4.5 %, 2 (0.6%, 8 (2.4%, 13 (3.9%, 5 (1.5% and 5 (1.5% P. multocida isolates as well as for tiamulin, gentamicin, tulathromycin, tilmicosin and ampicillin in 2 (2.4%, 2 (2.4%, 3 (3.6%, 3 (3.6% and 6 (7.2% H. parasuis isolates. In addition, moderate level of resistance to tiamulin was found in 60 (18.1% P. multocida isolates and high level of resistance for tetracycline was detected in 107 (32.2 % P. multocida isolates and in 23 (27.7 % H. parasuis isolates. Differences between resistance rates of P. multocida and H. parasuis were significant (P ≤ 0.5 only for tiamulin. These data confirmed that antimicrobial resistance is not very widespread among current porcine P. multocida and H. parasuis isolates in the Czech Republic.

Effect of Ampicillin, Streptomycin, Penicillin and Tetracycline on Metal Resistant and Non-Resistant Staphylococcus aureus

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Dagmar Chudobova

2014-03-01

Full Text Available There is an arising and concerning issue in the field of bacterial resistance, which is confirmed by the number of deaths associated with drug-resistant bacterial infections. The aim of this study was to compare the effects of antibiotics on Staphylococcus aureus non-resistant strain and strains resistant to cadmium or lead ions. Metal resistant strains were created by the gradual addition of 2 mM solution of metal ions (cadmium or lead to the S. aureus culture. An increasing antimicrobial effect of ampicillin, streptomycin, penicillin and tetracycline (0, 10, 25, 50, 75, 150, 225 and 300 µM on the resistant strains was observed using a method of growth curves. A significant growth inhibition (compared to control of cadmium resistant cells was observed in the presence of all the four different antibiotics. On the other hand, the addition of streptomycin and ampicillin did not inhibit the growth of lead resistant strain. Other antibiotics were still toxic to the bacterial cells. Significant differences in the morphology of cell walls were indicated by changes in the cell shape. Our data show that the presence of metal ions in the urban environment may contribute to the development of bacterial strain resistance to other substances including antibiotics, which would have an impact on public health.

Effect of Ampicillin, Streptomycin, Penicillin and Tetracycline on Metal Resistant and Non-Resistant Staphylococcus aureus

Science.gov (United States)

Chudobova, Dagmar; Dostalova, Simona; Blazkova, Iva; Michalek, Petr; Ruttkay-Nedecky, Branislav; Sklenar, Matej; Nejdl, Lukas; Kudr, Jiri; Gumulec, Jaromir; Tmejova, Katerina; Konecna, Marie; Vaculovicova, Marketa; Hynek, David; Masarik, Michal; Kynicky, Jindrich; Kizek, Rene; Adam, Vojtech

2014-01-01

There is an arising and concerning issue in the field of bacterial resistance, which is confirmed by the number of deaths associated with drug-resistant bacterial infections. The aim of this study was to compare the effects of antibiotics on Staphylococcus aureus non-resistant strain and strains resistant to cadmium or lead ions. Metal resistant strains were created by the gradual addition of 2 mM solution of metal ions (cadmium or lead) to the S. aureus culture. An increasing antimicrobial effect of ampicillin, streptomycin, penicillin and tetracycline (0, 10, 25, 50, 75, 150, 225 and 300 µM) on the resistant strains was observed using a method of growth curves. A significant growth inhibition (compared to control) of cadmium resistant cells was observed in the presence of all the four different antibiotics. On the other hand, the addition of streptomycin and ampicillin did not inhibit the growth of lead resistant strain. Other antibiotics were still toxic to the bacterial cells. Significant differences in the morphology of cell walls were indicated by changes in the cell shape. Our data show that the presence of metal ions in the urban environment may contribute to the development of bacterial strain resistance to other substances including antibiotics, which would have an impact on public health. PMID:24651395

Mutation induction in Haemophilus influenzae by ICR-191. Pt. 1

International Nuclear Information System (INIS)

Perdue, S.W.; Kimball, R.F.; McGray, P.C.; Tennessee Univ., Oak Ridge

1981-01-01

The investigation of mutagenic mechanisms in Haemophilus influenzae has been confined until now to mutagens that normally produce mainly base pair substitutions. This paper describes the development of a system suitable for detecting frameshift mutations induced by ICR-191. The system involves reversions from thymidine dependence to thymidine independence. Evidence is presented from a comparison of the responses to ICR-191 and to N-methyl-N'-nitro-N-nitrosoguanidine that the system is specific for frameshift mutations. The genetic recombination involved in transformation leads to a marked increase in spontaneous reversion of the frameshift mutations but not of the base substitution mutations. Presumably, this is a consequence of mispairing, with consequent change in the number of bases, during the recombination. (orig.)

A biphasic epigenetic switch controls immunoevasion, virulence and niche adaptation in non-typeable Haemophilus influenzae.

Science.gov (United States)

Atack, John M; Srikhanta, Yogitha N; Fox, Kate L; Jurcisek, Joseph A; Brockman, Kenneth L; Clark, Tyson A; Boitano, Matthew; Power, Peter M; Jen, Freda E-C; McEwan, Alastair G; Grimmond, Sean M; Smith, Arnold L; Barenkamp, Stephen J; Korlach, Jonas; Bakaletz, Lauren O; Jennings, Michael P

2015-07-28

Non-typeable Haemophilus influenzae contains an N(6)-adenine DNA-methyltransferase (ModA) that is subject to phase-variable expression (random ON/OFF switching). Five modA alleles, modA2, modA4, modA5, modA9 and modA10, account for over two-thirds of clinical otitis media isolates surveyed. Here, we use single molecule, real-time (SMRT) methylome analysis to identify the DNA-recognition motifs for all five of these modA alleles. Phase variation of these alleles regulates multiple proteins including vaccine candidates, and key virulence phenotypes such as antibiotic resistance (modA2, modA5, modA10), biofilm formation (modA2) and immunoevasion (modA4). Analyses of a modA2 strain in the chinchilla model of otitis media show a clear selection for ON switching of modA2 in the middle ear. Our results indicate that a biphasic epigenetic switch can control bacterial virulence, immunoevasion and niche adaptation in an animal model system.

Space-time clustering of ampicillin resistant Escherichia coli isolated from Danish pigs at slaughter between 1997 and 2005

DEFF Research Database (Denmark)

Abatih, E. N.; Ersbøll, A. K.; Wong, Danilo Lo Fo

2009-01-01

In Denmark, antimicrobial resistance in bacteria in animals, animal products and humans, is routinely monitored. This study aimed at determining whether the observed variations in the prevalence of ampicillin resistant Escherichia coli isolated from healthy pigs at slaughter were random....... The clusters of ampicillin resistant E coli appeared at the same time as the national consumption of ampicillin in pigs increased, however antimicrobial consumption at the herd level did not appear to have any effects on space-time clustering in this study. The results could serve as a platform to highlight...... or clustered in space and time. Data on E coli isolates between 1997 and 2005 were obtained from the Danish Integrated Antimicrobial Resistance Monitoring and Research Programme (DANMAP) whereas data on the quantity of ampicillin consumed was obtained from the Danish Register of Veterinary Medicines (Vet...

Human milk lactoferrin inactivates two putative colonization factors expressed by Haemophilus influenzae.

Science.gov (United States)

Qiu, J; Hendrixson, D R; Baker, E N; Murphy, T F; St Geme, J W; Plaut, A G

1998-10-13

Haemophilus influenzae is a major cause of otitis media and other respiratory tract disease in children. The pathogenesis of disease begins with colonization of the upper respiratory mucosa, a process that involves evasion of local immune mechanisms and adherence to epithelial cells. Several studies have demonstrated that human milk is protective against H. influenzae colonization and disease. In the present study, we examined the effect of human milk on the H. influenzae IgA1 protease and Hap adhesin, two autotransported proteins that are presumed to facilitate colonization. Our results demonstrated that human milk lactoferrin efficiently extracted the IgA1 protease preprotein from the bacterial outer membrane. In addition, lactoferrin specifically degraded the Hap adhesin and abolished Hap-mediated adherence. Extraction of IgA1 protease and degradation of Hap were localized to the N-lobe of the bilobed lactoferrin molecule and were inhibited by serine protease inhibitors, suggesting that the lactoferrin N-lobe may contain serine protease activity. Additional experiments revealed no effect of lactoferrin on the H. influenzae P2, P5, and P6 outer-membrane proteins, which are distinguished from IgA1 protease and Hap by the lack of an N-terminal passenger domain or an extracellular linker region. These results suggest that human milk lactoferrin may attenuate the pathogenic potential of H. influenzae by selectively inactivating IgA1 protease and Hap, thereby interfering with colonization. Future studies should examine the therapeutic potential of lactoferrin, perhaps as a supplement in infant formulas.

The Role of α-Defensins 1–3 in Antimicrobial Protection Forming in Children with Recurrent Bronchitis Caused by Bacteria of the Genus Haemophilus

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G.O. Lezhenko

2013-03-01

Full Text Available The level of α-defensins 1–3 (HNP 1–3 has been analyzed in the blood plasma of children with recurrent bronchitis caused by bacteria of the genus Haemophilus. It is shown that the level of HNP 1–3 in the blood plasma depends on the form of Haemophilus. Trigger of HNP 1–3 outflow for neutrophils was the presence of bacterial capsule while presence of L-forms of Haemophilus influenzae wasn’t associated with increase in synthesis of antimicrobial peptides that could be one of the factors of forming of Haemophilus antibiotic resistance.

Relationship between secretion of the Anton blood group antigen in saliva and adherence of Haemophilus influenzae to oropharynx epithelial cells

NARCIS (Netherlands)

van Alphen, L.; van Ham, M.; Geelen-van den Broek, L.; Pieters, T.

1989-01-01

Inhibition of adherence of bacteria to epithelial cells contributes to a reduction of infections by these bacteria. We have shown that the Anton blood group antigen, the erythrocyte receptor for Haemophilus influenzae (van Alphen et al. 1986, FEMS Microbiol. Lett. 37, 69-71), occurs in saliva, that

Multicentre in-vitro evaluation of the susceptibility of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis to ciprofloxacin, clarithromycin, co-amoxiclav and sparfloxacin

NARCIS (Netherlands)

HoogkampKorstanje, JAA; DirksGo, SIS; Kabel, P; Manson, WL; Stobberingh, EE; Vreede, RW; Davies, BI

Seven laboratories, including a reference laboratory, tested the susceptibility of Moraxella catarrhalis, Streptococcus pneumoniae and Haemophilus influenzae strains to ciprofloxacin, clarithromycin, co-amoxiclav and sparfloxacin with the Etest. A total of 976 strains were collected. The results

Identification of immunogenic outer membrane proteins of Haemophilus influenzae type b in the infant rat model system

International Nuclear Information System (INIS)

Hansen, E.J.; Frisch, C.F.; McDade, R.L. Jr.; Johnston, K.H.

1981-01-01

Outer membrane proteins of Haemophilus influenzae type b which are immunogenic in infant rats were identified by a radioimmunoprecipitation method. Intact cells of H. influenzae type b were radioiodinated by a lactoperoxidase-catalyzed procedure, and an outer membrane-containing fraction was prepared from these cells. These radioiodinated outer membranes were mixed with sera obtained from rats convalescing from systemic H. influenzae type b disease induced at 6 days of age, and the resultant (antibody-outer membrane protein antigen) complexes were extracted from these membranes by treatment with nonionic detergent and ethylenediaminetetraacetic acid. These soluble antibody-antigen complexes were isolated by means of adsorption to protein A-bearing staphylococci, and the radioiodinated protein antigens were identified by gel electrophoresis followed by autoradiography. Infant rats were shown to mount a readily detectable antibody response to several different proteins present in the outer membrane of H. influenzae type b. Individual infant rats were found to vary both qualitatively and quantitatively in their immune response to these immunogenic outer membrane proteins

DNA repair in Haemophilus influenzae: isolation and characterization of an ultraviolet sensitive mutator mutant

International Nuclear Information System (INIS)

Walter, R.B.

1985-01-01

DNA repair in Haemophilus influenzae appears to be quite different from that seen in Escherichia coli in that H. influenzae shows neither SOS nor adaptation phenomena. Repair of DNA lesions in H. influenzae has been seen to occur via recombinational, excision, and mismatch repair pathways acting independently of one another. The author has isolated an ultraviolet (UV)-sensitive mutator mutant (mutB1) of H. influenzae Rd which shows deficiencies in both recombinational and mismatch repair pathways. This mutant is sensitive to a variety of DNA damaging agents as well as being hypermutable by alkylating agents and base analogues. MutB1 cells do not show post-UV DNA breakdown but do begin excision after UV irradiation. Genetic transformation with UV-irradiated DNA on mut B1 recipients shows that high (HE) and low (LE) efficiency markers are transformed at a ratio of 1.0 as in the mismatch repair deficient hex 1 mutant; however, kinetics of UV-inactivation experiments indicate that HE markers are sensitized and act as LE markers do on wild type recipients. Thus, the mutB gene product appears to play a role in both DNA repair and genetic transformation. A model is outlined which presents a role for a DNA helicase in both DNA repair and genetic transformation of H. influenzae

Biofilm formation in Haemophilus parasuis: relationship with antibiotic resistance, serotype and genetic typing.

Science.gov (United States)

Zhang, Jianmin; Xu, Chenggang; Shen, Haiyan; Li, Jingyi; Guo, Lili; Cao, Guojie; Feng, Saixiang; Liao, Ming

2014-10-01

Biofilms are surface-associated microbial communities, which are encased in self-synthesized extracellular environment. Biofilm formation may trigger drug resistance and inflammation, resulting in persistent infections. Haemophilus parasuis is the etiological agent of a systemic disease, Glässer's disease, characterized by fibrinous polyserositis, arthritis and meningitis in pigs. The purpose of this study was to examine the correlation between biofilm and antibiotic resistance among the clinical isolates of H. parasuis. In the present study, we tested biofilm-forming ability of 110 H. parasuis isolates from various farms using polystyrene microtiter plate assays. Seventy-three isolates of H. parasuis (66.4%) showed biofilm formation and most of them performed weak biofilm-forming ability (38/73). All isolates were tested for antimicrobial susceptibility to 18 antimicrobial agents by the broth microdilution method. H. parasuis isolates showed very high resistance (>90%) to sulfanilamide, nalidixic acid, and trimethoprim. Resistance to eight antibiotics such as penicillin (41.1% vs 8.1%), ampicillin (31.5% vs 8.1%), amoxicillin (28.8% vs 5.4%), gentamicin (46.6% vs 24.3%), cefazolin (19.2% vs 2.7%), doxycycline (19.2% vs 8.1%), cefotaxime (11% vs 2.7%), and cefaclor (13.7% vs 5.4%) was comparatively higher among biofilm producers than non-biofilm producers. Pulsed-field gel electrophoresis (PFGE) analyses could distinguish various isolates. Our data indicated that H. parasuis field isolates were able to form biofilms in vitro. In addition, biofilm positive strains had positive correlation with resistance to β-lactams antibiotics. Thus, biofilm formation may play important roles during H. parasuis infections. Copyright © 2014. Published by Elsevier Ltd.

Polyarticular Septic Arthritis Caused by Haemophilus influenzae Serotype f in an 8-Month-Old Immunocompetent Infant: A Case Report and Review of the Literature

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Raheel Ahmed Ali

2015-01-01

Full Text Available Background. The standard use of vaccinations against pathogens has resulted in a decreased incidence of musculoskeletal infections caused by these previously common bacterial pathogens. Consequently, the incidence of infections caused by atypical bacteria is rising. This report presents a case of septic arthritis caused by non-type b H. influenzae in a pediatric patient. Methods. We report a case of an infant with polyarticular septic arthritis caused by H. influenzae serotype f. A literature review was conducted with the inclusion criteria of case reports and studies published between 2004 and 2013 addressing musculoskeletal H. influenzae infections. Results. An 8-month-old female presented with pain and swelling in her right ankle and left elbow. The patient was diagnosed with septic arthritis and underwent incision and drainage. Wound and blood cultures were positive for Haemophilus influenzae serotype f. In addition to treatment with IV antibiotics, the patient underwent immunocompetency studies, which were normal. Subsequent follow-up revealed eradication of the infection. Conclusions. Haemophilus influenzae non-type b may cause serious invasive infections such as sepsis or septic arthritis in children with or without predisposing factors such as immunodeficiency or asplenia. Optimal treatment includes surgical management, culture driven IV antibiotics, and an immunologic workup.

Frequency of Haemophilus spp. in urinary and and genital tract samples

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Tatjana Marijan,

2010-02-01

Full Text Available Aim To determine the prevalence and antibiotic susceptibility of Haemophilus influenzae and H. parainfluenzae isolated from the urinary and genital tracts. Methods Identification of strains bacteria Haemophilus spp. was carried out by using API NH identifi-cation system, and antibiotic susceptibility was performed by Kirby-Bauer disk diffusion method. Results A total number of 50 (0,03% H. influenzae and 14 (0,01% H. parainfluenzae (out of 180, 415 samples were isolated from genitourinary tract. From urine samples of the girls under 15 years of age these bacteria were isolated in 13 (0,88% and two (0,13% cases, respectively, and only in one case(0,11% of the UTI in boys (H. influenzae. In persons of fertile age, it was only H. influenzae bacteria that was found in urine samples of the five women (0,04% and in three men (0,22%. As a cause of vulvovaginitis, H. influenzae was isolated in four (5,63%, and H. parainfluenzae in two (2,82% girls. In persons of fertile age, H. influenzae was isolated from 10 (0,49% smears of the cervix, and in nine (1,74% male samples. H. parainfluenzae was isolated from seven (1,36% male samples. (p<0.01. Susceptibility testing of H. influenzae and H. parainfluenzae revealed that both pathogens were signifi- cantly resistant to cotrimoxasol only (26.0% and 42.9%, respectively. Conclusion In the etiology of genitourinary infections of girls during childhood, genital infections of women in fertile age (especially in pregnant women, and men with cases of epididimytis and/or orchitis,it is important to think about this rare and demanding bacteria in terms of cultivation.

Risk of Febrile Seizures and Epilepsy After Vaccination With Diphtheria, Tetanus, Acellular Pertussis, Inactivated Poliovirus, and Haemophilus Influenzae Type b

DEFF Research Database (Denmark)

Sun, Yuelian; Christensen, Jakob Christensen; Hviid, Anders

2012-01-01

-acellular pertussis–inactivated poliovirus– Haemophilus influenzae type b (DTaP-IPV-Hib) vaccine since September 2002. Objective To estimate the risk of febrile seizures and epilepsy after DTaP-IPV-Hib vaccination given at 3, 5, and 12 months. Design, Setting, and Participants A population-based cohort study of 378...

Impact of the Haemophilus influenzae type b vaccination program on HIB meningitis in Brazil Impacto do programa de vacinação contra meningites causadas por Haemophilus influenzae tipo b no Brasil

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Sybelle de Souza Castro Miranzi

2007-07-01

Full Text Available This study aimed to evaluate the impact of vaccination against Haemophilus influenzae type b (HIB in Brazil on the morbidity, mortality, and case fatality of HIB meningitis, using the Ministry of Health database and population data from the Brazilian Institute of Geography and Statistics (Instituto Brasileiro de Geografia e Estatística - IBGE. Impact was evaluated through a time series analysis (1983-2002, using regression forecasting (RF by dividing the time series into two periods: (a historical (1983-1998 and (b validation (1999-2002. Impact of the vaccination was positive, although more significant for incidence and mortality than for case fatality rates.A proposta deste trabalho foi avaliar o impacto da vacinação contra Haemophilus influenzae tipo b (HIB no Brasil sobre a morbi-mortalidade e a letalidade das meningites por HIB, a partir de base de dados fornecida pelo Ministério da Saúde e as estimativas populacionais provenientes do Instituto Brasileiro de Geografia e Estatística (IBGE. Para a avaliação do impacto utilizou-se análise de tendência temporal (1983-2002, aplicando-se a técnica RF (regression forecasting, dividindo-se a série em dois períodos: (a período histórico (1983-1998 e (b período de estimação (1999-2002. O impacto da vacinação foi positivo, embora tenha se revelado mais expressivo sobre a morbi-mortalidade que sobre a letalidade.

Activities of two novel macrolides, GW 773546 and GW 708408, compared with those of telithromycin, erythromycin, azithromycin, and clarithromycin against Haemophilus influenzae.

Science.gov (United States)

Kosowska, Klaudia; Credito, Kim; Pankuch, Glenn A; Hoellman, Dianne; Lin, Gengrong; Clark, Catherine; Dewasse, Bonifacio; McGhee, Pamela; Jacobs, Michael R; Appelbaum, Peter C

2004-11-01

The MIC at which 50% of strains are inhibited (MIC(50)) and the MIC(90) of GW 773546, a novel macrolide, were 1.0 and 2.0 microg/ml, respectively, for 223 beta-lactamase-positive, beta-lactamase-negative, and beta-lactamase-negative ampicillin-resistant Haemophilus influenzae strains. The MIC(50)s and MIC(90)s of GW 708408, a second novel macrolide, and telithromycin, an established ketolide, were 2.0 and 4.0 microg/ml, respectively, while the MIC(50) and MIC(90) of azithromycin were 1.0 and 2.0 microg/ml, respectively. The MIC(50) and MIC(90) of erythromycin were 4.0 and 8.0 microg/ml, respectively; and those of clarithromycin were 4.0 and 16.0 microg/ml, respectively. All compounds except telithromycin were bactericidal (99.9% killing) against nine strains at two times the MIC after 24 h. Telithromycin was bactericidal against eight of the nine strains. In addition, both novel macrolides and telithromycin at two times the MIC showed 99% killing of all nine strains after 12 h and 90% killing of all strains after 6 h. After 24 h, all drugs were bactericidal against four to seven strains when they were tested at the MIC. Ten of 11 strains tested by multistep selection analysis yielded resistant clones after 14 to 43 passages with erythromycin. Azithromycin gave resistant clones of all strains after 20 to 50 passages, and clarithromycin gave resistant clones of 9 of 11 strains after 14 to 41 passages. By comparison, GW 708408 gave resistant clones of 9 of 11 strains after 14 to 44 passages, and GW 773546 gave resistant clones of 10 of 11 strains after 14 to 45 passages. Telithromycin gave resistant clones of 7 of 11 strains after 18 to 45 passages. Mutations mostly in the L22 and L4 ribosomal proteins and 23S rRNA were detected in resistant strains selected with all compounds, with alterations in the L22 protein predominating. Single-step resistance selection studies at the MIC yielded spontaneous resistant mutants at frequencies of 1.5 x 10(-9) to 2.2 x 10(-6) with

Development of a diagnostic real-time polymerase chain reaction assay for the detection of invasive Haemophilus influenzae in clinical samples.

LENUS (Irish Health Repository)

Meyler, Kenneth L

2012-12-01

Since the introduction of the Haemophilus influenzae serotype b vaccine, invasive H. influenzae disease has become dominated by nontypeable (NT) strains. Several widely used molecular diagnostic methods have been shown to lack sensitivity or specificity in the detection of some of these strains. Novel real-time assays targeting the fucK, licA, and ompP2 genes were developed and evaluated. The fucK assay detected all strains of H. influenzae tested (n = 116) and had an analytical sensitivity of 10 genome copies\\/polymerase chain reaction (PCR). This assay detected both serotype b and NT H. influenzae in 12 previously positive specimens (culture and\\/or bexA PCR) and also detected H. influenzae in a further 5 of 883 culture-negative blood and cerebrospinal fluid (CSF) samples. The fucK assay has excellent potential as a diagnostic test for detection of typeable and nontypeable strains of invasive H. influenzae in clinical samples of blood and CSF.

Development of a diagnostic real-time polymerase chain reaction assay for the detection of invasive Haemophilus influenzae in clinical samples.

Science.gov (United States)

Meyler, Kenneth L; Meehan, Mary; Bennett, Desiree; Cunney, Robert; Cafferkey, Mary

2012-12-01

Since the introduction of the Haemophilus influenzae serotype b vaccine, invasive H. influenzae disease has become dominated by nontypeable (NT) strains. Several widely used molecular diagnostic methods have been shown to lack sensitivity or specificity in the detection of some of these strains. Novel real-time assays targeting the fucK, licA, and ompP2 genes were developed and evaluated. The fucK assay detected all strains of H. influenzae tested (n = 116) and had an analytical sensitivity of 10 genome copies/polymerase chain reaction (PCR). This assay detected both serotype b and NT H. influenzae in 12 previously positive specimens (culture and/or bexA PCR) and also detected H. influenzae in a further 5 of 883 culture-negative blood and cerebrospinal fluid (CSF) samples. The fucK assay has excellent potential as a diagnostic test for detection of typeable and nontypeable strains of invasive H. influenzae in clinical samples of blood and CSF. Copyright © 2012 Elsevier Inc. All rights reserved.

A plasmid carrying mucA and mucB genes from pKM101 in Haemophilus influenzae and Escherichia coli

International Nuclear Information System (INIS)

Spikes, D.; Setlow, J.K.

1989-01-01

The plasmid pMucAMucB, constructed from the Haemophilus influenzae vector pDM2, and a similar plasmid, constructed from pBR322, increased the survival after UV irradiation of Escherichia coli AB1157 with the umu-36 mutation and also caused UV-induced mutation in the E. coli strain. In H. influenzae, pMucAMucB caused a small but reproducible increase in survival after UV irradiation in wild-type cells and in a rec-1 mutant, but there was no increase in spontaneous mutation in the wild type or in the rec-1 mutant and no UV-induced mutation

Genes from plasmid pKM101 in Haemophilus influenzae: separation of functions of mucA and mucB

International Nuclear Information System (INIS)

Balganesh, M.; Setlow, J.K.

1985-01-01

Haemophilus influenzae, normally not mutable by UV, became UV mutable with a recombinant plasmid insertion. A 7.8-kilobase-pair (kbp) fragment of the plasmid pKM101 containing the mucA and mucB genes was ligated to the shuttle vector pDM2, and a Rec- strain of H. influenzae was transformed with the ligated mixture. All of the transformants, unlike the parent Rec- strain, were resistant to UV, could carry out postreplication repair and Weigle reactivation, showed greatly increased spontaneous mutation, and contained a plasmid carrying an insert of only 1.2 rather than 7.8 kbp. This plasmid in a umuC mutant strain of Escherichia coli complemented a pKM101 derivative lacking mucA function but with an intact mucB gene, although there was no complementation with a mucA+ mucB- plasmid, suggesting that the newly constructed plasmid coded for the mucA protein; this is in accord with the restriction analysis and hybridization between the plasmid and a probe containing all of the mucA gene but only a small fraction of mucB. When one of the H. influenzae Rec- transformants lost the plasmid, the resistance to UV was retained but the high spontaneous mutation and UV mutability were not. The fact that there was hybridization between the chromosome of the cured strain and a probe containing both muc genes but none when almost no mucB was present suggested that at least part of the mucB gene had been integrated into the Rec- chromosome. Five different postreplication repair-proficient strains became UV mutable and had high spontaneous mutation rates caused by the putative mucA plasmid, indicating that these strains already possessed a chromosomal equivalent of the mucB gene

Intravitreal Ampicillin Sodium for Antibiotic-Resistant Endophthalmitis: Streptococcus uberis First Human Intraocular Infection Report

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Raul Velez-Montoya

2010-01-01

Full Text Available Purpose. To describe the clinical characteristics, diagnosis, and treatment with intravitreal ampicillin sodium of a postoperative endophthalmitis case due to Streptococcus uberis; an environmental pathogen commonly seen in mastitis cases of lactating cows. Methods. Case Report. A 52-year-old, Hispanic diabetic patient who suddenly developed severe pain and severe loss of vision, following vitrectomy. Results. The patient was diagnosed with postoperative endophthalmitis secondary to a highly resistant strain of Streptococcus uberis that did not respond to intravitreal antibiotics. He was treated with an air-fluid interchange, anterior chamber washout, intravitreal ampicillin sodium (5 mg/0.1 mL, and silicon oil tamponade (5000 ck. The eye was anatomically stabilized, though there was no functional recovery. Conclusion. Streptococcus uberis is an uncommon pathogen to the human eye, which has unique features that help the strain in developing resistance to antibiotics. While treatment with intravitreal ampicillin is feasible, there are still concerns about its possible toxicity.

Costo-efectividad de la vacunación contra Haemophilus influenzae tipo b : un análisis de decisión para Cuba

NARCIS (Netherlands)

Carcía, A; Postma, Maarten; Gálvez, AM; Sierra, G

2002-01-01

The objective of the present study was to estimate the cost-effectiveness ratio of the therapeutic and prophylactic alternatives for treatment of meningitis caused by Haemophilus influenzae type b in less than one year old infants applying a mathematical model. A hypothetical setting with two

Structural determinants of the interaction between the Haemophilus influenzae Hap autotransporter and fibronectin.

Science.gov (United States)

Spahich, Nicole A; Kenjale, Roma; McCann, Jessica; Meng, Guoyu; Ohashi, Tomoo; Erickson, Harold P; St Geme, Joseph W

2014-06-01

Haemophilus influenzae is a Gram-negative cocco-bacillus that initiates infection by colonizing the upper respiratory tract. Hap is an H. influenzae serine protease autotransporter protein that mediates adherence, invasion and microcolony formation in assays with human epithelial cells and is presumed to facilitate the process of colonization. Additionally, Hap mediates adherence to fibronectin, laminin and collagen IV, extracellular matrix (ECM) proteins that are present in the respiratory tract and are probably important targets for H. influenzae colonization. The region of Hap responsible for adherence to ECM proteins has been localized to the C-terminal 511 aa of the Hap passenger domain (HapS). In this study, we characterized the structural determinants of the interaction between HapS and fibronectin. Using defined fibronectin fragments, we established that Hap interacts with the fibronectin repeat fragment called FNIII(1-2). Using site-directed mutagenesis, we found a series of motifs in the C-terminal region of HapS that contribute to the interaction with fibronectin. Most of these motifs are located on the F1 and F3 faces of the HapS structure, suggesting that the F1 and F3 faces may be responsible for the HapS-fibronectin interaction. © 2014 The Authors.

Quantitative fucK gene polymerase chain reaction on sputum and nasopharyngeal secretions to detect Haemophilus influenzae pneumonia.

Science.gov (United States)

Abdeldaim, Guma M K; Strålin, Kristoffer; Olcén, Per; Blomberg, Jonas; Mölling, Paula; Herrmann, Björn

2013-06-01

A quantitative polymerase chain reaction (PCR) for the fucK gene was developed for specific detection of Haemophilus influenzae. The method was tested on sputum and nasopharyngeal aspirate (NPA) from 78 patients with community-acquired pneumonia (CAP). With a reference standard of sputum culture and/or serology against the patient's own nasopharyngeal isolate, H. influenzae etiology was detected in 20 patients. Compared with the reference standard, fucK PCR (using the detection limit 10(5) DNA copies/mL) on sputum and NPA showed a sensitivity of 95.0% (19/20) in both cases, and specificities of 87.9% (51/58) and 89.5% (52/58), respectively. In a receiver operating characteristic curve analysis, sputum fucK PCR was found to be significantly superior to sputum P6 PCR for detection of H. influenzae CAP. NPA fucK PCR was positive in 3 of 54 adult controls without respiratory symptoms. In conclusion, quantitative fucK real-time PCR provides a sensitive and specific identification of H. influenzae in respiratory secretions. Copyright © 2013 Elsevier Inc. All rights reserved.

Substitutions in PBP3 confer resistance to both ampicillin and extended-spectrum cephalosporins in Haemophilus parainfluenzae as revealed by site-directed mutagenesis and gene recombinants

DEFF Research Database (Denmark)

Wienholtz, Nanna H; Ciechanowski, Aynur Barut; Nørskov-Lauritsen, Niels

2017-01-01

using site-directed mutagenesis. Recombinants were also generated using PCR-amplified ftsI from clinical strains encoding multiple amino acid substitutions. MICs of ampicillin, cefuroxime, cefotaxime and ceftriaxone were determined using Etest ® . Results: Transformation of a susceptible strain with fts...... for recombinants were lower than those for the donor strains. Using site-directed mutagenesis, no single substitution conferred resistance to the tested β-lactams, although V511A increased the MIC of cefuroxime to the intermediate category for intravenous administration. Recombinants encoding N526K...

ENFERMEDAD INVASORA POR HAEMOPHILUS INFLUENZAE ANTES Y DESPUÉS DE LA CAMPAÑA DE VACUNACIÓN EN LA POBLACIÓN INFANTIL DE LA COMUNIDAD VALENCIANA (1996-2000

Directory of Open Access Journals (Sweden)

Mercedes Goicoechea Sáez

2002-01-01

Full Text Available Fundamento: La introducción de la vacuna conjugada anti Haemophilus influenzae tipo b (Hib en niños ha provocado un llamativo descenso de la incidencia de la enfermedad por H. influenzae. El objetivo de este estudio es analizar las características más relevantes de la enfermedad invasora por H. influenzae en cuanto a la epidemiología, clínica, evolución y estado de vacunación de la población infantil de la Comunidad Valenciana en el periodo 1996-2000. Método: Los datos se recogen de las historias clínicas de los niños menores de 15 años que hayan presentado síntomas y signos clínicos sugestivos de enfermedad invasora con aislamiento de Haemophilus influenzae y/o que cumple con los criterios de definición de caso establecidos, atendidos en todos los hospitales públicos de la Comunidad Valenciana entre 1996 y 2000. La evolución de la incidencia se valoró mediante tasas de incidencia. La clínica y su evolución (secuelas y letalidad mediante la frecuencia y distribución por edad. Resultados: Se registraron un total de 36 casos de enfermedad invasora por Haemophilus influenzae. La tasa de incidencia en niños menores de 15 años pasó de 3,56/105 en 1996 a 1,07/105 en 1997 (coincidiendo con la campaña de vacunación y la posterior inclusión de la vacuna conjugada anti Hib en el Calendario de Vacunaciones Sistemáticas de la Comunidad Valenciana y 0,30/105 en 1998, situación que se sigue manteniendo en los años posteriores. El 53% de los casos se dan en menores de 18 meses. Tanto las secuelas como los fallecimientos se producen en la época anterior a la aplicación rutinaria de la vacuna conjugada. Ningún niño vacunado correctamente falleció. Se registraron 2 casos de H. influenzae tipo no b en niños vacunados. Conclusiones: La incidencia de la infección por Haemophilus influenzae tipo b disminuyó drásticamente desde el inicio de la vacunación sistemática de la población infantil.

Secondary Bacterial Infections Associated with Influenza Pandemics

Science.gov (United States)

Morris, Denise E.; Cleary, David W.; Clarke, Stuart C.

2017-01-01

Lower and upper respiratory infections are the fourth highest cause of global mortality (Lozano et al., 2012). Epidemic and pandemic outbreaks of respiratory infection are a major medical concern, often causing considerable disease and a high death toll, typically over a relatively short period of time. Influenza is a major cause of epidemic and pandemic infection. Bacterial co/secondary infection further increases morbidity and mortality of influenza infection, with Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus reported as the most common causes. With increased antibiotic resistance and vaccine evasion it is important to monitor the epidemiology of pathogens in circulation to inform clinical treatment and development, particularly in the setting of an influenza epidemic/pandemic. PMID:28690590

Secondary Bacterial Infections Associated with Influenza Pandemics

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Denise E. Morris

2017-06-01

Full Text Available Lower and upper respiratory infections are the fourth highest cause of global mortality (Lozano et al., 2012. Epidemic and pandemic outbreaks of respiratory infection are a major medical concern, often causing considerable disease and a high death toll, typically over a relatively short period of time. Influenza is a major cause of epidemic and pandemic infection. Bacterial co/secondary infection further increases morbidity and mortality of influenza infection, with Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus reported as the most common causes. With increased antibiotic resistance and vaccine evasion it is important to monitor the epidemiology of pathogens in circulation to inform clinical treatment and development, particularly in the setting of an influenza epidemic/pandemic.

Results from the Survey of Antibiotic Resistance (SOAR) 2014-16 in the Czech Republic.

Science.gov (United States)

Torumkuney, D; Zemlickova, H; Maruscak, M; Morrissey, I

2018-04-01

To determine the antibiotic susceptibility of isolates of Streptococcus pneumoniae and Haemophilus influenzae collected in 2014-16 from patients with community-acquired respiratory infections in the Czech Republic. MICs were determined by CLSI broth microdilution and susceptibility was assessed using CLSI, EUCAST and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints. S. pneumoniae isolates (n = 200) showed high rates of susceptibility (>95%) to amoxicillin, amoxicillin/clavulanic acid, penicillin [intravenous (iv) non-meningitis], ceftriaxone, cefuroxime and the fluoroquinolones using CLSI breakpoints. Susceptibility to cefaclor and trimethoprim/sulfamethoxazole was 94%-94.5%, to penicillin (oral) 91.5% and to the macrolides 89.5%. Susceptibility of H. influenzae (n = 197) to amoxicillin/clavulanic acid, ceftriaxone, cefuroxime, azithromycin and the fluoroquinolones was ≥98% by CLSI criteria. Rates of susceptibility to the remaining agents were ≥75% except for clarithromycin at 37.1%. Great variability was seen across breakpoints, especially for the macrolides, cefaclor and cefuroxime (oral), 98.0% of H. influenzae showing susceptibility to the latter by CLSI criteria, 69.5% by PK/PD and 1.5% by EUCAST standards. The β-lactamase rate was 13.7% with no β-lactamase-negative-ampicillin-resistant (BLNAR) isolates by CLSI criteria. Antibiotic resistance among the two major respiratory pathogens remained low in the Czech Republic. These findings support local clinicians in continuing the historically restrictive use of antibiotics in the Czech Republic, with selection of narrower-spectrum agents for the empirical therapy of community-acquired respiratory tract infections. This highlights one of the great benefits of continuous surveillance of antimicrobial resistance: knowledge of current local resistance patterns reduces the need to choose broad-spectrum agents that contribute to increasing resistance worldwide.

Incidência de meningite por Haemophilus influenzae no RS 1999-2010: impacto da cobertura vacinal Incidence of meningitis caused by Haemophilus influenzae in the state of Rio Grande do Sul 1999-2010: impact of vaccination campaign

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Marli Matiko Anraku de Campos

2013-05-01

Full Text Available O objetivo deste artigo é analisar e verificar a situação epidemiológica das meningites causadas pelo agente Haemophilus influenzae tipo b nos últimos 10 anos no Rio Grande do Sul. Estudo retrospectivo, descritivo, utilizando o sistema de dados de notificação de meningites, e cobertura vacinal, armazenados em base on line Tabnet - Tabulação de dados Epidemiológicos - CEVS/SES/RS, abrangendo o período de 1999 a 2010. Foram utilizados casos notificados e confirmados, tendo como critério de seleção o ano de inicio dos sintomas, idade, diagnostico e evolução. Foi analisado o Estado do Rio Grande do Sul, representado por 19 coordenadorias de saúde. Comparações entre proporções foram avaliadas pelo teste de z. No RS foram notificados 3043 casos confirmados de meningite bacteriana, sendo 6,77% dos casos causados por H. influenzae. O coeficiente de incidência da meningite por H. influenzae, sem considerar faixa etária, caiu significativamente (95,6% após 1999, assim como a mortalidade. Crianças menores de um ano continuam sendo as mais acometidas (52%, não havendo alteração na letalidade. Os resultados apresentados revelaram um impacto positivo das estratégias de vacinação contra Hib no Estado do Rio Grande do Sul nos últimos dez anos.This article seeks to analyze and update the epidemiological situation of meningitis caused by Haemophilus influenzae type b in the past 10 years in the state of Rio Grande do Sul (RS. It is a retrospective, descriptive study, which used the data notification system of meningitis and vaccination campaign coverage, stored in the Epidemiological TABNET online database, for the period from 1999 to 2010. Cases notified and confirmed were used and the selection criteria were the year when the symptoms were detected, age, diagnosis, and evolution. Nineteen health centers in the state of Rio Grande do Sul were analyzed. The z-test was used to evaluate comparisons between the proportions. In the

Effect of Multiple Mutations in the Hemoglobin- and Hemoglobin-Haptoglobin-Binding Proteins, HgpA, HgpB, and HgpC, of Haemophilus influenzae Type b

OpenAIRE

Morton, Daniel J.; Whitby, Paul W.; Jin, Hongfan; Ren, Zhen; Stull, Terrence L.

1999-01-01

Haemophilus influenzae requires heme for growth and can utilize hemoglobin and hemoglobin-haptoglobin as heme sources. We previously identified two hemoglobin- and hemoglobin-haptoglobin-binding proteins, HgpA and HgpB, in H. influenzae HI689. Insertional mutation of hgpA and hgpB, either singly or together, did not abrogate the ability to utilize or bind either hemoglobin or the hemoglobin-haptoglobin complex. A hemoglobin affinity purification method was used to isolate a protein of approxi...

Development and validation of an Haemophilus influenzae supragenome hybridization (SGH array for transcriptomic analyses.

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Benjamin A Janto

Full Text Available We previously carried out the design and testing of a custom-built Haemophilus influenzae supragenome hybridization (SGH array that contains probe sequences to 2,890 gene clusters identified by whole genome sequencing of 24 strains of H. influenzae. The array was originally designed as a tool to interrogate the gene content of large numbers of clinical isolates without the need for sequencing, however, the data obtained is quantitative and is thus suitable for transcriptomic analyses. In the current study RNA was extracted from H. influenzae strain CZ4126/02 (which was not included in the design of the array converted to cDNA, and labelled and hybridized to the SGH arrays to assess the quality and reproducibility of data obtained from these custom-designed chips to serve as a tool for transcriptomics. Three types of experimental replicates were analyzed with all showing very high degrees of correlation, thus validating both the array and the methods used for RNA profiling. A custom filtering pipeline for two-condition unpaired data using five metrics was developed to minimize variability within replicates and to maximize the identification of the most significant true transcriptional differences between two samples. These methods can be extended to transcriptional analysis of other bacterial species utilizing supragenome-based arrays.

Comparison of Established Diagnostic Methodologies and a Novel Bacterial smpB Real-Time PCR Assay for Specific Detection of Haemophilus influenzae Isolates Associated with Respiratory Tract Infections.

Science.gov (United States)

Reddington, Kate; Schwenk, Stefan; Tuite, Nina; Platt, Gareth; Davar, Danesh; Coughlan, Helena; Personne, Yoann; Gant, Vanya; Enne, Virve I; Zumla, Alimuddin; Barry, Thomas

2015-09-01

Haemophilus influenzae is a significant causative agent of respiratory tract infections (RTI) worldwide. The development of a rapid H. influenzae diagnostic assay that would allow for the implementation of infection control measures and also improve antimicrobial stewardship for patients is required. A number of nucleic acid diagnostics approaches that detect H. influenzae in RTIs have been described in the literature; however, there are reported specificity and sensitivity limitations for these assays. In this study, a novel real-time PCR diagnostic assay targeting the smpB gene was designed to detect all serogroups of H. influenzae. The assay was validated using a panel of well-characterized Haemophilus spp. Subsequently, 44 Haemophilus clinical isolates were collected, and 36 isolates were identified as H. influenzae using a gold standard methodology that combined the results of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and a fucK diagnostic assay. Using the novel smpB diagnostic assay, 100% concordance was observed with the gold standard, demonstrating a sensitivity of 100% (95% confidence interval [CI], 90.26% to 100.00%) and a specificity of 100% (95% CI, 63.06% to 100.00%) when used on clinical isolates. To demonstrate the clinical utility of the diagnostic assay presented, a panel of lower RTI samples (n = 98) were blindly tested with the gold standard and smpB diagnostic assays. The results generated were concordant for 94/98 samples tested, demonstrating a sensitivity of 90.91% (95% CI, 78.33% to 97.47%) and a specificity of 100% (95% CI, 93.40% to 100.00%) for the novel smpB assay when used directly on respiratory specimens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Genomic Variability of Haemophilus influenzae Isolated from Mexican Children Determined by Using Enterobacterial Repetitive Intergenic Consensus Sequences and PCR

OpenAIRE

Gomez-De-Leon, Patricia; Santos, Jose I.; Caballero, Javier; Gomez, Demostenes; Espinosa, Luz E.; Moreno, Isabel; Piñero, Daniel; Cravioto, Alejandro

2000-01-01

Genomic fingerprints from 92 capsulated and noncapsulated strains of Haemophilus influenzae from Mexican children with different diseases and healthy carriers were generated by PCR using the enterobacterial repetitive intergenic consensus (ERIC) sequences. A cluster analysis by the unweighted pair-group method with arithmetic averages based on the overall similarity as estimated from the characteristics of the genomic fingerprints, was conducted to group the strains. A total of 69 fingerprint...

Genomic DNA fingerprinting of clinical Haemophilus influenzae isolates by polymerase chain reaction amplification: comparison with major outer-membrane protein and restriction fragment length polymorphism analysis

NARCIS (Netherlands)

van Belkum, A.; Duim, B.; Regelink, A.; Möller, L.; Quint, W.; van Alphen, L.

1994-01-01

Non-capsulate strains of Haemophilus influenzae were genotyped by analysis of variable DNA segments obtained by amplification of genomic DNA with the polymerase chain reaction (PCR fingerprinting). Discrete fragments of 100-2000 bp were obtained. The reproducibility of the procedure was assessed by

GENOMIC DNA-FINGERPRINTING OF CLINICAL HAEMOPHILUS-INFLUENZAE ISOLATES BY POLYMERASE CHAIN-REACTION AMPLIFICATION - COMPARISON WITH MAJOR OUTER-MEMBRANE PROTEIN AND RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM ANALYSIS

NARCIS (Netherlands)

VANBELKUM, A; DUIM, B; REGELINK, A; MOLLER, L; QUINT, W; VANALPHEN, L

Non-capsulate strains of Haemophilus influenzae were genotyped by analysis of variable DNA segments obtained by amplification of genomic DNA with the polymerase chain reaction (PCR fingerprinting). Discrete fragments of 100-2000 bp were obtained. The reproducibility of the procedure was assessed by

Klebsiella pneumonia strains moderately resistant to ampicillin and carbenicillin: characterization of a new β-lactamase

OpenAIRE

Labia, Roger; Fabre, Christian; Masson, Jean-Michel; Barthelemy, Michel; Heitz, Madeleine; Pitton, Jean-S

2017-01-01

Klebsiella pneumoniae strain 11-03, moderately resistant to ampicillin and carbenicillin, produces one constitutive β-lactamase with an isoelectric point of 7.10 and a molecular weight of 20,000±500. The enzymatic activity is directed primarily against the penicillins, ampicillin being the best substrate. Some cephalosporins are also hydrolyzed to some extent but the affinity of the enzyme for these antibiotics is low (high Km values). It has not been possible to determine whether the biogene...

The C-Terminal Fragment of the Internal 110-Kilodalton Passenger Domain of the Hap Protein of Nontypeable Haemophilus influenzae Is a Potential Vaccine Candidate

OpenAIRE

Liu, Dai-Fang; Mason, Kathryn W.; Mastri, Maria; Pazirandeh, Mehran; Cutter, David; Fink, Doran L.; St. Geme, Joseph W.; Zhu, Duzhang; Green, Bruce A.

2004-01-01

Nontypeable Haemophilus influenzae is a major causative agent of bacterial otitis media in children. H. influenzae Hap autotransporter protein is an adhesin composed of an outer membrane Hapβ region and a moiety of an extracellular internal 110-kDa passenger domain called HapS. The HapS moiety promotes adherence to human epithelial cells and extracellular matrix proteins, and it also mediates bacterial aggregation and microcolony formation. A recent work (D. L. Fink, A. Z. Buscher, B. A. Gree...

The Seroepidemiology of Haemophilus Influenzae Type b in Children Under 6 Years Old in Khorramabad, Iran

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N. Ansari

2015-05-01

Full Text Available Background and Objective: Haemophilus influenzae type b (Hib is now recognized as an agent of bacterial meningitis in Asia. Polyribosil Ribitol Phosphate (PRP capsule are in all of the strains and IgG antibodies can be target. Due to limited studies on H. influenzae type b in the country and the lack of sufficient information on the status of carriers, achieve a comprehensive model of the spread of the bacteria in the carrier's most vulnerable children is the aim of this study. Material and Methods: In this study, 194 (49% female and 51% male serum samples were collected from children under 6 years old referred to medical centers in Korram Abad. The serological study of H. influenzae type b was carried using anti-H. influenzae PRP IgG antibodies kit by indirect enzyme linked immunosorbent assay (ELISA. Results: Of 194 children under 6 years-old screened for H. influenzae-specific IgG antibodies with ELISA, 6 (3 percent were IgG seropositive. Prevalence of bacteria in children under 2 years was 67% that demonstrated no significant association between seropositivity in subjects and place of residence of children with the prevalence of bacteria. Conclusion: The prevalence of H. influenzae type b seropositivity in our study was 3% of the total sample. In current study, a higher percentage of males than females were seropositive and frequency of predominant bacteria in patients younger than 2 years. The age factor is a variable that positively affects serum. Regarding to non-Hib vaccination in children, the presence of the bacteria in children can be important.

Haemophilus influenzae from Patients with Chronic Obstructive Pulmonary Disease Exacerbation Induce More Inflammation than Colonizers

Science.gov (United States)

Chin, Cecilia L.; Manzel, Lori J.; Lehman, Erin E.; Humlicek, Alicia L.; Shi, Lei; Starner, Timothy D.; Denning, Gerene M.; Murphy, Timothy F.; Sethi, Sanjay; Look, Dwight C.

2005-01-01

Rationale: Airway infection with Haemophilus influenzae causes airway inflammation, and isolation of new strains of this bacteria is associated with increased risk of exacerbations in patients with chronic obstructive pulmonary disease (COPD). Objective: To determine whether strains of H. influenzae associated with exacerbations cause more inflammation than strains that colonize the airways of patients with COPD. Methods: Exacerbation strains of H. influenzae were isolated from patients during exacerbation of clinical symptoms with subsequent development of a homologous serum antibody response and were compared with colonization strains that were not associated with symptom worsening or an antibody response. Bacterial strains were compared using an in vivo mouse model of airway infection and in vitro cell culture model of bacterial adherence and defense gene and signaling pathway activation in primary human airway epithelial cells. Results: H. influenzae associated with exacerbations caused more airway neutrophil recruitment compared with colonization strains in the mouse model of airway bacterial infection. Furthermore, exacerbation strains adhered to epithelial cells in significantly higher numbers and induced more interleukin-8 release after interaction with airway epithelial cells. This effect was likely mediated by increased activation of the nuclear factor-κB and p38 mitogen-activated protein kinase signaling pathways. Conclusions: The results indicate that H. influenzae strains isolated from patients during COPD exacerbations often induce more airway inflammation and likely have differences in virulence compared with colonizing strains. These findings support the concept that bacteria infecting the airway during COPD exacerbations mediate increased airway inflammation and contribute to decreased airway function. PMID:15805181

Preventing drug resistance in severe influenza

Science.gov (United States)

Dobrovolny, Hana; Deecke, Lucas

2015-03-01

Severe, long-lasting influenza infections are often caused by new strains of influenza. The long duration of these infections leads to an increased opportunity for the emergence of drug resistant mutants. This is particularly problematic for new strains of influenza since there is often no vaccine, so drug treatment is the first line of defense. One strategy for trying to minimize drug resistance is to apply periodic treatment. During treatment the wild-type virus decreases, but resistant virus might increase; when there is no treatment, wild-type virus will hopefully out-compete the resistant virus, driving down the number of resistant virus. We combine a mathematical model of severe influenza with a model of drug resistance to study emergence of drug resistance during a long-lasting infection. We apply periodic treatment with two types of antivirals: neuraminidase inhibitors, which block release of virions; and adamantanes, which block replication of virions. We compare the efficacy of the two drugs in reducing emergence of drug resistant mutants and examine the effect of treatment frequency on the emergence of drug resistant mutants.

Haemophilus influenzae tipo b: situação epidemiológica no Estado de Minas Gerais, Brasil, 1993 a 1997 Haemophilus influenzae type b: epidemiological situation in the State of Minas Gerais, Brazil, 1993-1997

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Sybelle de Souza Castro Miranzi

2003-10-01

Full Text Available Entre as doenças invasivas causadas pelo Haemophilus influenzae tipo b (Hib, destacam-se, pela freqüência e gravidade, as pneumonias e as meningites. No período de 1993 a 1997, foram notificados, em Minas Gerais, 720 casos de meningites por Hib, sendo a causa mais freqüente de meningite bacteriana em menores de um ano e a segunda causa no total de meningites. Entretanto, estimou-se uma ocorrência total de 1.160 casos considerando as meningites bacterianas não especificadas. O total de casos estimados de doença invasiva por Hib parece justificar a recente inclusão da vacina no esquema básico de imunizações. O alto custo da vacina reforça a necessidade de melhorar a vigilância epidemiológica da meningite, que constitui uma das fragilidades das ações de controle desta doença.Among Haemophilus influenzae type b (Hib invasive diseases, pneumonia and meningitis are the most relevant in public health due to their frequency and severity. From 1993 to 1997, there were 720 cases of Hib meningitis in Minas Gerais State, Brazil, representing the most frequent cause of bacterial meningitis in infants (< 1 year and the second most frequent among all causes of meningitis. The total estimated cases of invasive Hib diseases thus appear to justify the recent inclusion of the vaccine in the basic immunization protocol. The vaccine's high cost reinforces the need for more precise monitoring of the etiological diagnosis of meningitis cases, representing one of the weaknesses in the prevailing epidemiological surveillance system.

Characterization of the N-Acetyl-5-neuraminic Acid-binding Site of the Extracytoplasmic Solute Receptor (SiaP) of Nontypeable Haemophilus influenzae Strain 2019

Energy Technology Data Exchange (ETDEWEB)

Johnston, Jason W.; Coussens, Nathan P.; Allen, Simon; Houtman, Jon C.D.; Turner, Keith H.; Zaleski, Anthony; Ramaswamy, S.; Gibson, Bradford W.; Apicella, Michael A. (Iowa); (Buck Inst.)

2012-11-14

Nontypeable Haemophilus influenzae is an opportunistic human pathogen causing otitis media in children and chronic bronchitis and pneumonia in patients with chronic obstructive pulmonary disease. The outer membrane of nontypeable H. influenzae is dominated by lipooligosaccharides (LOS), many of which incorporate sialic acid as a terminal nonreducing sugar. Sialic acid has been demonstrated to be an important factor in the survival of the bacteria within the host environment. H. influenzae is incapable of synthesizing sialic acid and is dependent on scavenging free sialic acid from the host environment. To achieve this, H. influenzae utilizes a tripartite ATP-independent periplasmic transporter. In this study, we characterize the binding site of the extracytoplasmic solute receptor (SiaP) from nontypeable H. influenzae strain 2019. A crystal structure of N-acetyl-5-neuraminic acid (Neu5Ac)-bound SiaP was determined to 1.4 {angstrom} resolution. Thermodynamic characterization of Neu5Ac binding shows this interaction is enthalpically driven with a substantial unfavorable contribution from entropy. This is expected because the binding of SiaP to Neu5Ac is mediated by numerous hydrogen bonds and has several buried water molecules. Point mutations targeting specific amino acids were introduced in the putative binding site. Complementation with the mutated siaP constructs resulted either in full, partial, or no complementation, depending on the role of specific residues. Mass spectrometry analysis of the O-deacylated LOS of the R127K point mutation confirmed the observation of reduced incorporation of Neu5Ac into the LOS. The decreased ability of H. influenzae to import sialic acid had negative effects on resistance to complement-mediated killing and viability of biofilms in vitro, confirming the importance of sialic acid transport to the bacterium.

Incidence of invasive Haemophilus influenzae type b disease in Italian children

International Nuclear Information System (INIS)

Tozzi, Alberto E.; Salmaso, Stefania; Atti, Marta L. Ciofi degli; Panei, Pietro; Anemona, Alessandra; Scuderi, Gabriella; Wassilak, Steven G.F.

1997-01-01

To estimate the incidence of Haemophilus influenzae type b (Hib) invasive disease in Italian infants we performed a prospective study in a cohort of newborns enrolled for a randomized trial on safety and efficacy of three pertussis vaccines and followed for onset of serious disease or pertussis. The overall cumulative incidence observed in 15,601 children was 51.3/100,000 for all invasive Hib infections and 38.4/100,000 for Hib meningitis, over 27 months of observation. The incidence density of all invasive Hib diseases was 28.7/100,000 person-years, while meningitis occurred with an incidence of 21.5/100,000 person-years. Among the eight cases detected, six were meningitis, one sepsis, and one cellulitis. The child with sepsis died. The incidence and epidemiology of invasive Hib disease in Italy are comparable to those reported from other European countries. Cost-benefit analyses are needed for planning Italian vaccination policy

Enfermedad invasora por Haemophilus Influenzae antes y después de la campaña de vacunación en la población infantil de la Comunidad Valenciana (1996-2000

Directory of Open Access Journals (Sweden)

Goicoechea Sáez Mercedes

2002-01-01

Full Text Available Fundamento: La introducción de la vacuna conjugada anti Haemophilus influenzae tipo b (Hib en niños ha provocado un llamativo descenso de la incidencia de la enfermedad por H. influenzae. El objetivo de este estudio es analizar las características más relevantes de la enfermedad invasora por H. influenzae en cuanto a la epidemiología, clínica, evolución y estado de vacunación de la población infantil de la Comunidad Valenciana en el periodo 1996-2000. Método: Los datos se recogen de las historias clínicas de los niños menores de 15 años que hayan presentado síntomas y signos clínicos sugestivos de enfermedad invasora con aislamiento de Haemophilus influenzae y/o que cumple con los criterios de definición de caso establecidos, atendidos en todos los hospitales públicos de la Comunidad Valenciana entre 1996 y 2000. La evolución de la incidencia se valoró mediante tasas de incidencia. La clínica y su evolución (secuelas y letalidad mediante la frecuencia y distribución por edad. Resultados: Se registraron un total de 36 casos de enfermedad invasora por Haemophilus influenzae. La tasa de incidencia en niños menores de 15 años pasó de 3,56/10(5 en 1996 a 1,07/10(5 en 1997 (coincidiendo con la campaña de vacunación y la posterior inclusión de la vacuna conjugada anti Hib en el Calendario de Vacunaciones Sistemáticas de la Comunidad Valenciana y 0,30/10(5 en 1998, situación que se sigue manteniendo en los años posteriores. El 53% de los casos se dan en menores de 18 meses. Tanto las secuelas como los fallecimientos se producen en la época anterior a la aplicación rutinaria de la vacuna conjugada. Ningún niño vacunado correctamente falleció. Se registraron 2 casos de H. influenzae tipo no b en niños vacunados. Conclusiones: La incidencia de la infección por Haemophilus influenzae tipo b disminuyó drásticamente desde el inicio de la vacunación sistemática de la población infantil.

Capsule Typing of Haemophilus influenzae by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry.

Science.gov (United States)

Månsson, Viktor; Gilsdorf, Janet R; Kahlmeter, Gunnar; Kilian, Mogens; Kroll, J Simon; Riesbeck, Kristian; Resman, Fredrik

2018-03-01

Encapsulated Haemophilus influenzae strains belong to type-specific genetic lineages. Reliable capsule typing requires PCR, but a more efficient method would be useful. We evaluated capsule typing by using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Isolates of all capsule types (a-f and nontypeable; n = 258) and isogenic capsule transformants (types a-d) were investigated. Principal component and biomarker analyses of mass spectra showed clustering, and mass peaks correlated with capsule type-specific genetic lineages. We used 31 selected isolates to construct a capsule typing database. Validation with the remaining isolates (n = 227) showed 100% sensitivity and 92.2% specificity for encapsulated strains (a-f; n = 61). Blinded validation of a supplemented database (n = 50) using clinical isolates (n = 126) showed 100% sensitivity and 100% specificity for encapsulated strains (b, e, and f; n = 28). MALDI-TOF mass spectrometry is an accurate method for capsule typing of H. influenzae.

Detection of Ampicillin Resistance Genes (bla in Clinical Isolates of Escherichia coli with Polymerase Chain Reaction Method

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Tiana Milanda

2014-09-01

Full Text Available Escherichia coli is a rod negative Gram which could be pathogenic, if its value increases or located in outer gastrointestinal tract. Pathogenic E. coli will produce enterotoxin which will cause diarrhoea or infection in urine tract. Ampicilin was one of particular antibiotics to overcome infection. Ampicilin nowadays is no longer used as primary medicine, because of its resistance case. The aim of this research is to detect the presence of gene which is responsible to ampicilin resistant E. coli. We used isolated midstream urine from cystitis object in Hasan Sadikin Hospital (RSHS as samples. Polymerase Chain Reaction (PCR method (colony-PCR and DNA-PCR were done to invenstigate the antibiotic resistency. Based on the result of antibiotic susceptibility testing to ampicillin, E. coli samples were resistant to ampicilin. Elektroforegram products of colony-PCR and DNA-PCR showed that the resistance case of ampicilin caused by bla gene (199 bp. Selective and rational antibiotic treatment is required to prevent ampicillin resistance in patients with symptoms

Haemophilus influenzae Isolated From Men With Acute Urethritis: Its Pathogenic Roles, Responses to Antimicrobial Chemotherapies, and Antimicrobial Susceptibilities.

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Ito, Shin; Hatazaki, Kyoko; Shimuta, Ken; Kondo, Hiromi; Mizutani, Kosuke; Yasuda, Mitsuru; Nakane, Keita; Tsuchiya, Tomohiro; Yokoi, Shigeaki; Nakano, Masahiro; Ohinishi, Makoto; Deguchi, Takashi

2017-04-01

There have been few comprehensive studies on Haemophilus influenza-positive urethritis. In this retrospective study, we enrolled 68 men with H. influenzae-positive urethritis, including coinfections with Neisseria gonorrhoeae, Chlamydia trachomatis, and/or genital mycoplasmas: 2, 3, 20, and 43 treated with ceftriaxone, levofloxacin, sitafloxacin, and extended-release azithromycin (azithromycin-SR), respectively. We assessed microbiological outcomes in 54 men and clinical outcomes in 46 with H. influenzae-positive monomicrobial nongonococcal urethritis. We determined minimum inhibitory concentrations (MICs) of 6 antimicrobial agents for 59 pretreatment isolates. H. influenzae was eradicated from the men treated with ceftriaxone, levofloxacin, or sitafloxacin. The eradication rate with azithromycin-SR was 85.3%. The disappearance or alleviation of urethritis symptoms and the decreases in leukocyte counts in first-voided urine were significantly associated with the eradication of H. influenzae after treatment. For the isolates, ceftriaxone, levofloxacin, sitafloxacin, azithromycin, tetracycline, and doxycycline MICs were ≤0.008-0.25, 0.008-0.5, 0.001-0.008, 0.12-1, 0.25-16, and 0.25-2 μg/mL, respectively. The azithromycin MICs for 3 of 4 strains persisting after azithromycin-SR administration were 1 μg/mL. H. influenzae with an azithromycin MIC of 1 μg/mL increased chronologically. H. influenzae showed good responses to the chemotherapies for urethritis. The significant associations of the clinical outcomes of the chemotherapies with their microbiological outcomes suggested that H. influenzae could play pathogenic roles in urethritis. All isolates, except for one with decreased susceptibility to tetracyclines, were susceptible to the examined agents. However, the increase in H. influenzae with an azithromycin MIC of 1 μg/mL might threaten efficacies of azithromycin regimens on H. influenzae-positive urethritis.

Presence of the resistance genes vanC1 and pbp5 in phenotypically vancomycin and ampicillin susceptible Enterococcus faecalis.

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Schwaiger, Karin; Bauer, Johann; Hörmansdorfer, Stefan; Mölle, Gabriele; Preikschat, Petra; Kämpf, Peter; Bauer-Unkauf, Ilse; Bischoff, Meike; Hölzel, Christina

2012-08-01

Ampicillin and vancomycin are important antibiotics for the therapy of Enterococcus faecalis infections. The ampicillin resistance gene pbp5 is intrinsic in Enterococcus faecium. The vanC1 gene confers resistance to vancomycin and serves as a species marker for Enterococcus gallinarum. Both genes are chromosomally located. Resistance to ampicillin and vancomycin was determined in 484 E. faecalis of human and porcine origin by microdilution. Since E. faecalis are highly skilled to acquire resistance genes, all strains were investigated for the presence of pbp5 (and, in positive strains, for the penicillin-binding protein synthesis repressor gene psr) and vanC1 (and, in positive strains, for vanXYc and vanT) by using polymerase chain reaction (PCR). One porcine and one human isolate were phenotypically resistant to ampicillin; no strain was vancomycin resistant. Four E. faecalis (3/1 of porcine/human origin) carried pbp5 (MIC=1 mg/L), and four porcine strains were vanC1 positive (minimum inhibitory concentration [MIC]=1 mg/L). Real-time reverse transcriptase (RT)-PCR revealed that the genes were not expressed. The psr gene was absent in the four pbp5-positive strains; the vanXYc gene was absent in the four vanC1-positive strains. However, vanT of the vanC gene cluster was detected in two vanC1-positive strains. To our knowledge, this is the first report on the presence of pbp5, identical with the "E. faecium pbp5 gene," and of vanC1/vanT in E. faecalis. Even if resistance is not expressed in these strains, this study shows that E. faecalis have a strong ability to acquire resistance genes-and potentially to spread them to other bacteria. Therefore, close monitoring of this species should be continued.

Reversal of Ampicillin Resistance in MRSA via Inhibition of Penicillin-Binding Protein 2a by Acalypha wilkesiana

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Carolina Santiago

2014-01-01

Full Text Available The inhibitory activity of a semipure fraction from the plant, Acalypha wilkesiana assigned as 9EA-FC-B, alone and in combination with ampicillin, was studied against methicillin-resistant Staphylococcus aureus (MRSA. In addition, effects of the combination treatment on PBP2a expression were investigated. Microdilution assay was used to determine the minimal inhibitory concentrations (MIC. Synergistic effects of 9EA-FC-B with ampicillin were determined using the fractional inhibitory concentration (FIC index and kinetic growth curve assay. Western blot experiments were carried out to study the PBP2a expression in treated MRSA cultures. The results showed a synergistic effect between ampicillin and 9EA-FC-B treatment with the lowest FIC index of 0.19 (synergism ≤ 0.5. The presence of 9EA-FC-B reduced the MIC of ampicillin from 50 to 1.56 μg mL−1. When ampicillin and 9EA-FC-B were combined at subinhibitory level, the kinetic growth curves were suppressed. The antibacterial effect of 9EA-FC-B and ampicillin was shown to be synergistic. The synergism is due the ability of 9EA-FC-B to suppress the activity of PBP2a, thus restoring the susceptibility of MRSA to ampicillin. Corilagin was postulated to be the constituent responsible for the synergistic activity showed by 9EA-FC-B.

Tendência das meningites por Haemophilus influenzae tipo b no Brasil, em menores de 5 anos, no período de 1983 a 2002 Trends in Haemophilus influenzae type b meningitis in Brazil in children under five years of age from 1983 through 2002

Directory of Open Access Journals (Sweden)

Sybelle de Souza Castro Miranzi

2006-10-01

Full Text Available Trata-se de um estudo ecológico, tipo série histórica (1983-2002, onde foram calculados os coeficientes de incidência, mortalidade e letalidade de meningites por Haemophilus influenzae , tipo b, no Brasil, e avaliou-se a tendência da morbi-mortalidade em menores de 5 anos. Para a análise de tendência dos coeficientes construíram-se modelos de regressão polinomial para as faixas etárias de The study was based on an ecological design using a historical time series (1983-2002, related to Haemophilus influenzae type b meningitis in Brazil. Incidence, mortality and case-fatality rates, as well as trends in incidence and morbidity-mortality were estimated in children less than 5 years of age. Polynomial regression analysis was used to analyze trends, adopting a significance level of 0.05. 43.9% of confirmed cases occurred in infants less than 1 year old and 38.7% in children 1-4 years old. The observed rates were also highest in these two age strata. The incidence and mortality rates showed an increasing trend, until approximately 1999, when a quick decline was observed. The study results reinforce the effectiveness of the Vaccination Program against HIB in Brazil, which benefited age ranges that did not receive the vaccine (Herd Immunity.

Identification, distribution, and expression of novel genes in 10 clinical isolates of nontypeable Haemophilus influenzae.

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Shen, Kai; Antalis, Patricia; Gladitz, John; Sayeed, Sameera; Ahmed, Azad; Yu, Shujun; Hayes, Jay; Johnson, Sandra; Dice, Bethany; Dopico, Richard; Keefe, Randy; Janto, Benjamin; Chong, William; Goodwin, Joseph; Wadowsky, Robert M; Erdos, Geza; Post, J Christopher; Ehrlich, Garth D; Hu, Fen Z

2005-06-01

We hypothesize that Haemophilus influenzae, as a species, possesses a much greater number of genes than that found in any single H. influenzae genome. This supragenome is distributed throughout naturally occurring infectious populations, and new strains arise through autocompetence and autotransformation systems. The effect is that H. influenzae populations can readily adapt to environmental stressors. The supragenome hypothesis predicts that significant differences exist between and among the genomes of individual infectious strains of nontypeable H. influenzae (NTHi). To test this prediction, we obtained 10 low-passage NTHi clinical isolates from the middle ear effusions of patients with chronic otitis media. DNA sequencing was performed with 771 clones chosen at random from a pooled genomic library. Homology searching demonstrated that approximately 10% of these clones were novel compared to the H. influenzae Rd KW20 genome, and most of them did not match any DNA sequence in GenBank. Amino acid homology searches using hypothetical translations of the open reading frames revealed homologies to a variety of proteins, including bacterial virulence factors not previously identified in the NTHi isolates. The distribution and expression of 53 of these genes among the 10 strains were determined by PCR- and reverse transcription PCR-based analyses. These unique genes were nonuniformly distributed among the 10 isolates, and transcription of these genes in planktonic cultures was detected in 50% (177 of 352) of the occurrences. All of the novel sequences were transcribed in one or more of the NTHi isolates. Seventeen percent (9 of 53) of the novel genes were identified in all 10 NTHi strains, with each of the remaining 44 being present in only a subset of the strains. These genic distribution analyses were more effective as a strain discrimination tool than either multilocus sequence typing or 23S ribosomal gene typing methods.

Phylogeny of the genus Haemophilus as determined by comparison of partial infB sequences

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Hedegaard, J; Okkels, H; Bruun, B

2001-01-01

A 453 bp fragment of infB, the gene encoding translation initiation factor 2, was sequenced and compared from 66 clinical isolates and type strains of Haemophilus species and related bacteria. Analysis of the partial infB sequences obtained suggested that the human isolates dependent on X and V...... factor, H. influenzae, H. haemolyticus, H. aegyptius and some cryptic genospecies of H. influenzae, were closely related to each other. H. parainfluenzae constituted a heterogeneous group within the boundaries of the genus, whereas H. aphrophilus/paraphrophilus and Actinobacillus actinomycetemcomitans...... were only remotely related to the type species of the genus Haemophilus H. parahaemolyticus and H. paraphrohaemolyticus took up an intermediary position and may not belong in the genus Haemophilus sensu stricto. Ambiguous results were obtained with seven isolates tentatively identified as H. segnis...

Haemophilus parainfluenzae Strain ATCC 33392 Forms Biofilms In Vitro and during Experimental Otitis Media Infections.

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Pang, Bing; Swords, W Edward

2017-09-01

Haemophilus parainfluenzae is a nutritionally fastidious, Gram-negative bacterium with an oropharyngeal/nasopharyngeal carriage niche that is associated with a range of opportunistic infections, including infectious endocarditis and otitis media (OM). These infections are often chronic/recurrent in nature and typically involve bacterial persistence within biofilm communities that are highly resistant to host clearance. This study addresses the primary hypothesis that H. parainfluenzae forms biofilm communities that are important determinants of persistence in vivo The results from in vitro biofilm studies confirmed that H. parainfluenzae formed biofilm communities within which the polymeric matrix was mainly composed of extracellular DNA and proteins. Using a chinchilla OM infection model, we demonstrated that H. parainfluenzae formed surface-associated biofilm communities containing bacterial and host components that included neutrophil extracellular trap (NET) structures and that the bacteria mainly persisted in these biofilm communities. We also used this model to examine the possible interaction between H. parainfluenzae and its close relative Haemophilus influenzae , which is also commonly carried within the same host environments and can cause OM. The results showed that coinfection with H. influenzae promoted clearance of H. parainfluenzae from biofilm communities during OM infection. The underlying mechanisms for bacterial persistence and biofilm formation by H. parainfluenzae and knowledge about the survival defects of H. parainfluenzae during coinfection with H. influenzae are topics for future work. Copyright © 2017 American Society for Microbiology.

Evidence for covalent attachment of phospholipid to the capsular polysaccharide of Haemophilus influenzae type b

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Kuo, J.S.; Doelling, V.W.; Graveline, J.F.; McCoy, D.W.

1985-01-01

Cells of Haemophilus influenzae type b were grown in a liquid medium containing [ 3 H]palmitate or [ 14 C]ribose or both for two generations of exponential growth. Radiolabeled type-specific capsular polysaccharide, polyribosyl ribitol phosphate (PRP), was purified from the culture supernatant by Cetavlon precipitation, ethanol fractionation, and hydroxylapatite and Sepharose 4B chromatography. The doubly labeled ( [ 3 H]palmitate and [ 14 C]ribose) PRP preparation was found to coelute in a single peak from a Sepharose 4B column, suggesting that both precursors were incorporated into the purified PRP. A singly labeled ( [ 3 H]palmitate) purified PRP preparation was found to be quantitatively immune precipitated by human serum containing antibody against PRP. Only after acid, alkaline, or phospholipase A2 treatment of PRP labeled with [ 3 H]palmitate or [ 3 H]palmitate and [ 14 C]ribose followed by chloroform-methanol extraction could most of the 3 H-radioactivity be recovered in the organic phase. The chloroform-soluble acid-hydrolyzed or phospholipase A2-treated product was identified as palmitic acid after thin-layer chromatography. These results strongly suggest that a phospholipid moiety is covalently associated with the H. influenzae type b polysaccharide PRP

[Naturally occurring oseltamivir resistance in influenza A.

DEFF Research Database (Denmark)

Madsen, Laura; Nielsen, Alex; Lundgren, Jens

2010-01-01

in the development of resistance. The best prevention strategy remains vaccination of the general population to avoid immunity. Future antiviral treatment calls for knowledge about resistance to existing types of influenza and the availability of all three types of antiviral medication. Udgivelsesdato: 2010-Aug......During the last two influenza seasons, one of the predominant influenza A types (H1N1) has developed complete resistance to oseltamivir, the primary treatment option. The virus does, however, remain sensitive to zanamavir and amantadine. There is no unequivocal explanation for this slide...

[Naturally occurring oseltamivir resistance in influenza A.

DEFF Research Database (Denmark)

Madsen, Laura; Nielsen, Alex; Lundgren, Jens

2010-01-01

During the last two influenza seasons, one of the predominant influenza A types (H1N1) has developed complete resistance to oseltamivir, the primary treatment option. The virus does, however, remain sensitive to zanamavir and amantadine. There is no unequivocal explanation for this slide...... in the development of resistance. The best prevention strategy remains vaccination of the general population to avoid immunity. Future antiviral treatment calls for knowledge about resistance to existing types of influenza and the availability of all three types of antiviral medication. Udgivelsesdato: 2010-Aug...

Biofilm-specific extracellular matrix proteins of non-typeable Haemophilus influenzae

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Wu, Siva; Baum, Marc M.; Kerwin, James; Guerrero-Given, Debbie; Webster, Simon; Schaudinn, Christoph; VanderVelde, David; Webster, Paul

2014-01-01

Non-typeable Haemophilus influenzae (NTHi), a human respiratory tract pathogen can form colony biofilms in vitro. Bacterial cells and the amorphous extracellular matrix (ECM) constituting the biofilm can be separated using sonication. The ECM from 24 hr and 96 hr NTHi biofilms contained polysaccharides and proteinaceous components as detected by NMR and FTIR spectroscopy. More conventional chemical assays on the biofilm ECM confirmed the presence of these components and also DNA. Proteomics revealed eighteen proteins present in biofilm ECM that were not detected in planktonic bacteria. One ECM protein was unique to 24 hr biofilms, two were found only in 96 hr biofilms, and fifteen were present in the ECM of both 24 hr and 96 hr NTHi biofilms. All proteins identified were either associated with bacterial membranes or were cytoplasmic proteins. Immunocytochemistry showed two of the identified proteins, a DNA-directed RNA polymerase and the outer membrane protein OMP P2, associated with bacteria and biofilm ECM. Identification of biofilm-specific proteins present in immature biofilms is an important step in understanding the in vitro process of NTHi biofilm formation. The presence of a cytoplasmic protein and a membrane protein in the biofilm ECM of immature NTHi biofilms suggests that bacterial cell lysis may be a feature of early biofilm formation. PMID:24942343

Live Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis activate the inflammatory response trhough Toll-like receptors 2, 4, and 9 in species-specific patterns

DEFF Research Database (Denmark)

Mogensen, T.H.; Paludan, Søren Riis; Kilian, Mogens

2006-01-01

activation by live bacteria. Here, we demonstrate that live Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis, the three principal causes of bacterial meningitis, use distinct sets of TLRs to trigger the inflammatory response. Using human embryonic kidney 293 cell lines......, each overexpressing one type of TLR, we found that S. pneumoniae triggered activation of the transcription factor nuclear factor-kappaB and expression of interleukin-8, only in cells expressing TLR2 or -9. The same response was evoked by H. influenzae in cells expressing TLR2 or -4 and by N...... and confirmed the essential role of these TLRs and also identified differential functions of TLRs in activation of the inflammatory response. Collectively, we here demonstrate that S. pneumoniae, H. influenzae, and N. meningitidis each activate several TLRs in species-specific patterns and show that infection...

Coinfection with Haemophilus influenzae promotes pneumococcal biofilm formation during experimental otitis media and impedes the progression of pneumococcal disease.

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Weimer, Kristin E D; Armbruster, Chelsie E; Juneau, Richard A; Hong, Wenzhou; Pang, Bing; Swords, W Edward

2010-10-01

Otitis media is an extremely common pediatric infection and is mostly caused by bacteria that are carried within the nasopharyngeal microbiota. It is clear that most otitis media cases involve simultaneous infection with multiple agents. Chinchillas were infected with nontypeable Haemophilus influenzae, Streptococcus pneumoniae, or a combination of both organisms, and the course of disease was compared. In vitro experiments were also performed to address how coinfection impacts biofilm formation. The incidence of systemic disease was reduced in coinfected animals, compared with those infected with pneumococcus alone. Pneumococci were present within surface-attached biofilms in coinfected animals, and a greater proportion of translucent colony type was observed in the coinfected animals. Because this colony type has been associated with pneumococcal biofilms, the impact of coinfection on pneumococcal biofilm formation was investigated. The results clearly show enhanced biofilm formation in vitro by pneumococci in the presence of H. influenzae. Based on these data, we conclude that coinfection with H. influenzae facilitates pneumococcal biofilm formation and persistence on the middle ear mucosal surface. This enhanced biofilm persistence correlates with delayed emergence of opaque colony variants within the bacterial population and a resulting decrease in systemic infection.

Crystal structure of the Haemophilus influenzae Hap adhesin reveals an intercellular oligomerization mechanism for bacterial aggregation

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Meng, Guoyu; Spahich, Nicole; Kenjale, Roma; Waksman, Gabriel; St Geme, Joseph W

2011-01-01

Bacterial biofilms are complex microbial communities that are common in nature and are being recognized increasingly as an important determinant of bacterial virulence. However, the structural determinants of bacterial aggregation and eventual biofilm formation have been poorly defined. In Gram-negative bacteria, a major subgroup of extracellular proteins called self-associating autotransporters (SAATs) can mediate cell–cell adhesion and facilitate biofilm formation. In this study, we used the Haemophilus influenzae Hap autotransporter as a prototype SAAT to understand how bacteria associate with each other. The crystal structure of the H. influenzae HapS passenger domain (harbouring the SAAT domain) was determined to 2.2 Å by X-ray crystallography, revealing an unprecedented intercellular oligomerization mechanism for cell–cell interaction. The C-terminal SAAT domain folds into a triangular-prism-like structure that can mediate Hap–Hap dimerization and higher degrees of multimerization through its F1–F2 edge and F2 face. The intercellular multimerization can give rise to massive buried surfaces that are required for overcoming the repulsive force between cells, leading to bacterial cell–cell interaction and formation of complex microcolonies. PMID:21841773

Pacific region influenza surveillance for oseltamivir resistance.

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Miller, Heather B; Gose, Remedios B; Nagata, Mark T; Sciulli, Rebecca H; Whelen, A Christian

2012-05-01

Hawaii and the United States-affiliated Pacific islands (USAPI) host over 8 million travelers annually, most of whom originate in Asia, Australia, and the Americas where prevalence of oseltamivir resistance in 2009 pandemic influenza A (H1N1) has been reported to be 2.5-3.5%. To survey a collection of samples from Hawaii and the USAPI that had tested positive for the 2009 pandemic influenza A (H1N1) virus by RTI-PCR to assess whether antiviral resistance emerged in these island communities during the 2009 H1N1 pandemic. We examined RNA extracted from Hawaiian and USAPI cases for the neuraminidase H275Y mutation associated with oseltamivir resistance by pyrosequencing. Two hundred and sixty-three (263) 2009 pandemic influenza A (H1N1) positive specimens were tested and 263/263 (100%) were shown to lack the mutation most commonly associated with oseltamivir resistance. There was no evidence of oseltamivir resistant A(H1N1)pdm09 virus during the 2009 pandemic in the Pacific islands despite considerable travel exposure. Geographic isolation, the lack of a "second wave" of pandemic influenza, judicious antiviral use, aggressive vaccination, and below average tourism due to the global economic crisis may have been contributing factors. Continued surveillance and vigilance is necessary to monitor unpredictable influenza activity. Copyright © 2012 Elsevier B.V. All rights reserved.

Nonencapsulated Streptococcus pneumoniae causes otitis media during single-species infection and during polymicrobial infection with nontypeable Haemophilus influenzae.

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Murrah, Kyle A; Pang, Bing; Richardson, Stephen; Perez, Antonia; Reimche, Jennifer; King, Lauren; Wren, John; Swords, W Edward

2015-07-01

Streptococcus pneumoniae strains lacking capsular polysaccharide have been increasingly reported in carriage and disease contexts. Since most cases of otitis media involve more than one bacterial species, we aimed to determine the capacity of a nonencapsulated S. pneumoniae clinical isolate to induce disease in the context of a single-species infection and as a polymicrobial infection with nontypeable Haemophilus influenzae. Using the chinchilla model of otitis media, we found that nonencapsulated S. pneumoniae colonizes the nasopharynx following intranasal inoculation, but does not readily ascend into the middle ear. However, when we inoculated nonencapsulated S. pneumoniae directly into the middle ear, the bacteria persisted for two weeks post-inoculation and induced symptoms consistent with chronic otitis media. During coinfection with nontypeable H. influenzae, both species persisted for one week and induced polymicrobial otitis media. We also observed that nontypeable H. influenzae conferred passive protection from killing by amoxicillin upon S. pneumoniae from within polymicrobial biofilms in vitro. Therefore, based on these results, we conclude that nonencapsulated pneumococci are a potential causative agent of chronic/recurrent otitis media, and can also cause mutualistic infection with other opportunists, which could complicate treatment outcomes. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Nonencapsulated or nontypeable Haemophilus influenzae are more likely than their encapsulated or serotypeable counterparts to have mutations in their fucose operon.

Science.gov (United States)

Shuel, Michelle L; Karlowsky, Kathleen E; Law, Dennis K S; Tsang, Raymond S W

2011-12-01

Population biology of Haemophilus influenzae can be studied by multilocus sequence typing (MLST), and isolates are assigned sequence types (STs) based on nucleotide sequence variations in seven housekeeping genes, including fucK. However, the ST cannot be assigned if one of the housekeeping genes is absent or cannot be detected by the current protocol. Occasionally, strains of H. influenzae have been reported to lack the fucK gene. In this study, we examined the prevalence of this mutation among our collection of H. influenzae isolates. Of the 704 isolates studied, including 282 encapsulated and 422 nonencapsulated isolates, nine were not typeable by MLST owing to failure to detect the fucK gene. All nine fucK-negative isolates were nonencapsulated and belonged to various biotypes. DNA sequencing of the fucose operon region confirmed complete deletion of genes in the operon in seven of the nine isolates, while in the remaining two isolates, some of the genes were found intact or in parts. The significance of these findings is discussed.

Expression of urease by Haemophilus influenzae during human respiratory tract infection and role in survival in an acid environment

Science.gov (United States)

2011-01-01

Background Nontypeable Haemophilus influenzae is a common cause of otitis media in children and lower respiratory tract infection in adults with chronic obstructive pulmonary disease (COPD). Prior studies have shown that H. influenzae expresses abundant urease during growth in the middle ear of the chinchilla and in pooled human sputum, suggesting that expression of urease is important for colonization and infection in the hostile environments of the middle ear and in the airways in adults. Virtually nothing else is known about the urease of H. influenzae, which was characterized in the present study. Results Analysis by reverse transcriptase PCR revealed that the ure gene cluster is expressed as a single transcript. Knockout mutants of a urease structural gene (ureC) and of the entire ure operon demonstrated no detectable urease activity indicating that this operon is the only one encoding an active urease. The ure operon is present in all strains tested, including clinical isolates from otitis media and COPD. Urease activity decreased as nitrogen availability increased. To test the hypothesis that urease is expressed during human infection, purified recombinant urease C was used in ELISA with pre acquisition and post infection serum from adults with COPD who experienced infections caused by H. influenzae. A total of 28% of patients developed new antibodies following infection indicating that H. influenzae expresses urease during airway infection. Bacterial viability assays performed at varying pH indicate that urease mediates survival of H. influenzae in an acid environment. Conclusions The H. influenzae genome contains a single urease operon that mediates urease expression and that is present in all clinical isolates tested. Nitrogen availability is a determinant of urease expression. H. influenzae expresses urease during human respiratory tract infection and urease is a target of the human antibody response. Expression of urease enhances viability in an acid

Immunoglobulin G avidities in infants in Mexico after primary immunization with three doses of polyribosylribitol phosphate-tetanus toxoid Haemophilus influenzae type b vaccine.

Science.gov (United States)

Gómez-de-León, Patricia; Díaz-García, F Javier; Villaseñor-Sierra, Alberto; Segura, Jorge; Carranza, Martha I; Arredondo-Garcia, José Luis; Santos, José Ignacio

2008-06-01

Serum immunoglobulin G concentrations and avidities specific to Haemophilus influenzae type b (Hib) were measured in 208 children living in Guadalajara and Mexico City. Protective concentrations were found in 98.9% and 100.0% of participants, respectively. Geometric mean concentrations differed between both populations and/or among age groups. Mean avidities differed only among the 7- to 12-month-old children. Diphtheria-tetanus-whole-cell pertussis-hepatitis B-Hib primary vaccination seems to induce protection in Mexican children.

Nationwide surveillance of bacterial respiratory pathogens conducted by the surveillance committee of Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2012: General view of the pathogens' antibacterial susceptibility.

Science.gov (United States)

Yanagihara, Katsunori; Watanabe, Akira; Aoki, Nobuki; Matsumoto, Tetsuya; Yoshida, Masaki; Sato, Junko; Wakamura, Tomotaro; Sunakawa, Keisuke; Kadota, Junichi; Kiyota, Hiroshi; Iwata, Satoshi; Kaku, Mitsuo; Hanaki, Hideaki; Ohsaki, Yoshinobu; Fujiuchi, Satoru; Takahashi, Manabu; Takeuchi, Kenichi; Takeda, Hiroaki; Ikeda, Hideki; Miki, Makoto; Nakanowatari, Susumu; Takahashi, Hiroshi; Utagawa, Mutsuko; Nishiya, Hajime; Kawakami, Sayoko; Morino, Eriko; Takasaki, Jin; Mezaki, Kazuhisa; Chonabayashi, Naohiko; Tanaka, Chie; Sugiura, Hideko; Goto, Hajime; Saraya, Takeshi; Kurai, Daisuke; Katono, Yasuhiro; Inose, Rika; Niki, Yoshihito; Takuma, Takahiro; Kudo, Makoto; Ehara, Shigeru; Sato, Yoshimi; Tsukada, Hiroki; Watabe, Nobuei; Honma, Yasuo; Mikamo, Hiroshige; Yamagishi, Yuka; Nakamura, Atsushi; Ohashi, Minoru; Seki, Masafumi; Hamaguchi, Shigeto; Toyokawa, Masahiro; Fujikawa, Yasunori; Mitsuno, Noriko; Ukimura, Akira; Miyara, Takayuki; Nakamura, Takahito; Mikasa, Keiichi; Kasahara, Kei; Ui, Koji; Fukuda, Saori; Nakamura, Akihiro; Morimura, Mika; Yamashita, Mikio; Takesue, Yoshio; Wada, Yasunao; Sugimoto, Keisuke; Kusano, Nobuchika; Nose, Motoko; Mihara, Eiichirou; Kuwabara, Masao; Doi, Masao; Watanabe, Yaeko; Tokuyasu, Hirokazu; Hino, Satoshi; Negayama, Kiyoshi; Mukae, Hiroshi; Kawanami, Toshinori; Ota, Toshiyuki; Fujita, Masaki; Honda, Junichi; Hiramatsu, Kazufumi; Aoki, Yosuke; Fukuoka, Mami; Magarifuchi, Hiroki; Nagasawa, Zenzo; Kaku, Norihito; Fujita, Jiro; Higa, Futoshi; Tateyama, Masao

2017-09-01

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from the patients in Japan was conducted by Japanese Society of Chemotherapy, Japanese association for infectious diseases and Japanese society for Clinical Microbiology in 2012. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period between January and December in 2012 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical Laboratory Standard Institutes. Susceptibility testing was evaluated in 1236 strains (232 Staphylococcus aureus, 225 Streptococcus pneumoniae, 16 Streptococcus pyogenes, 231 Haemophilus influenzae, 147 Moraxella catarrhalis, 167 Klebsiella pneumoniae and 218 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was 51.3%, and those of penicillin-intermediate S. pneumoniae was 0.4%. Among H. influenzae, 5.6% of them were found to be β-lactamase-producing ampicillin-resistant strains, and 37.2% to be β-lactamase-non-producing ampicillin-resistant strains. Extended spectrum β-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo β-lactamase were 4.2% and 3.2%, respectively. Continuous national surveillance is important to determine the actual situation of the resistance shown by bacterial respiratory pathogens to antimicrobial agents. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Oxygen-independent inactivation of Haemophilus influenzae transforming DNA by monochromatic radiation: action spectrum, effect of histidine and repair

Energy Technology Data Exchange (ETDEWEB)

Cabrera-Juarez, E; Setlow, J K; Swenson, P A; Peak, M J

1976-01-01

The action spectrum for the oxygen-independent inactivation of native transforming DNA from Haemophilus influenzae with near-uv radiation revealed a shoulder beginning at 334 and extending to 460 nm. The presence of 0.2 M histidine during irradiation produced a small increase in inactivation at 254, 290 and 313 nm, a large increase at 334 nm and a decrease in inactivation at 365, 405, and 460 nm. Photoreactivation did not reverse the DNA damage produced at pH 7.0 at 334, 365, 405 and 460 nm, but did reactivate the DNA after irradiation at 254, 290 and 313 nm. The inactivation of DNA irradiated at 254, 290 and 313 nm was considerably greater when the transforming ability was assayed in an excision-defective mutant compared with the wild type, although DNA irradiated at 334, 365, 405 and 460 nm showed smaller differences. These results suggest that the oxygen-independent inactivation of H. influenzae DNA at pH 7 by irradiation at 334, 365, 405 and 460 nm is caused by lesions other than pyrimidine dimers.

Susceptibilities of Haemophilus influenzae and Moraxella catarrhalis to ABT-773 compared to their susceptibilities to 11 other agents.

Science.gov (United States)

Credito, K L; Lin, G; Pankuch, G A; Bajaksouzian, S; Jacobs, M R; Appelbaum, P C

2001-01-01

The activity of the ketolide ABT-773 against Haemophilus and Moraxella was compared to those of 11 other agents. Against 210 Haemophilus influenzae strains (39.0% beta-lactamase positive), microbroth dilution tests showed that azithromycin and ABT-773 had the lowest MICs (0.5 to 4.0 and 1.0 to 8.0 microg/ml, respectively), followed by clarithromycin and roxithromycin (4.0 to >32.0 microg/ml). Of the beta-lactams, ceftriaxone had the lowest MICs (32.0 microg/ml). Against 50 Moraxella catarrhalis strains, all of the compounds except amoxicillin and cefprozil were active. Time-kill studies against 10 H. influenzae strains showed that ABT-773, at two times the MIC, was bactericidal against 9 of 10 strains, with 99% killing of all strains at the MIC after 24 h; at 12 h, ABT-773 gave 90% killing of all strains at two times the MIC. At 3 and 6 h, killing by ABT-773 was slower, with 99.9% killing of four strains at two times the MIC after 6 h. Similar results were found for azithromycin, with slightly slower killing by erythromycin, clarithromycin, and roxithromycin, especially at earlier times. beta-Lactams were bactericidal against 8 to 10 strains at two times the MIC after 24 h, with slower killing at earlier time periods. Most compounds gave good killing of five M. catarrhalis strains, with beta-lactams killing more rapidly than other drugs. ABT-773 and azithromycin gave the longest postantibiotic effects (PAEs) of the ketolide-macrolide-azalide group tested (4.4 to >8.0 h), followed by clarithromycin, erythromycin, and roxithromycin. beta-Lactam PAEs were similar and shorter than those of the ketolide-macrolide-azalide group for all strains tested.

Crystal Structure of Homoserine Transacetylase from Haemophilus Influenzae Reveals a New Family of alpha/beta-Hydrolases

Energy Technology Data Exchange (ETDEWEB)

Mirza,I.; Nazi, I.; Korczynska, M.; Wright, G.; Berghuis, A.

2005-01-01

Homoserine transacetylase catalyzes one of the required steps in the biosynthesis of methionine in fungi and several bacteria. We have determined the crystal structure of homoserine transacetylase from Haemophilus influenzae to a resolution of 1.65 A. The structure identifies this enzyme to be a member of the alpha/beta-hydrolase structural superfamily. The active site of the enzyme is located near the end of a deep tunnel formed by the juxtaposition of two domains and incorporates a catalytic triad involving Ser143, His337, and Asp304. A structural basis is given for the observed double displacement kinetic mechanism of homoserine transacetylase. Furthermore, the properties of the tunnel provide a rationale for how homoserine transacetylase catalyzes a transferase reaction vs. hydrolysis, despite extensive similarity in active site architecture to hydrolytic enzymes.

CD4+ T-cell Responses Among Adults and Young Children In Response to Streptococcus pneumoniae and Haemophilus influenzae Vaccine Candidate Protein Antigens

OpenAIRE

Sharma, Sharad K.; Roumanes, David; Almudevar, Anthony; Mosmann, Tim R.; Pichichero, Michael E.

2013-01-01

We characterized cytokine profiles of CD4+ T-helper (h) cells in adults and young children to ascertain if responses occur to next-generation candidate vaccine antigens PspA, PcpA, PhtD, PhtE, Ply, LytB of Streptococcus pneumonia (Spn) and Protein D and OMP26 of non-typeable Haemophilus influenzae (NTHi). Adults had vaccine antigen-specific Th1 - and Th2 cells responsive to all antigens evaluated whereas young children had significant numbers of vaccine antigen-specific CD4+ T cells producing...

Vigilancia de serotipos en infecciones invasivas por Haemophilus influenzae en la Argentina en la era de la vacuna conjugada contra el serotipo b durante el período 2005-2010

OpenAIRE

Efron, Adriana M.; Moscoloni, María A.; Reijtman, Vanesa R.; Regueira, Mabel

2013-01-01

La introducción de la vacuna contra Haemophilus influenzae tipo b en los programas de inmunización de muchos países produjo una reducción marcada en la incidencia de enfermedad invasiva causada por este serotipo y en su portación y un incremento de otros tipos capsulares y de aislamientos no capsulados. Se estudiaron 313 aislamientos de H. influenzae recuperados de sitio estéril, provenientes de pacientes pediátricos y adultos con enfermedad invasiva atendidos en 90 hospitales de la Red Nacio...

Evaluation of polymorphisms in pbp4 gene and genetic diversity in penicillin-resistant, ampicillin-susceptible Enterococcus faecalis from hospitals in different states in Brazil.

Science.gov (United States)

Infante, Victor Hugo Pacagnelli; Conceição, Natália; de Oliveira, Adriana Gonçalves; Darini, Ana Lúcia da Costa

2016-04-01

The aim of the present study was to verify whether penicillin-resistant, ampicillin-susceptible Enterococcus faecalis (PRASEF) occurred in Brazil prior to the beginning of the 21st century, and to verify whether ampicillin susceptibility can predict susceptibility to other β-lactams in E. faecalis with this inconsistent phenotype. The presence of polymorphisms in the pbp4 gene and genetic diversity among the isolates were investigated. Of 21 PRASEF analyzed, 5 (23.8%) and 4 (19.0%) were imipenem and piperacillin resistant simultaneously by disk diffusion and broth dilution respectively, contradicting the current internationally accepted standards of susceptibility testing. Sequencing of pbp4 gene revealed an amino acid substitution (Asp-573→Glu) in all PRASEF isolates but not in the penicillin-susceptible, ampicillin-susceptible E. faecalis. Most PRASEF (90.5%) had related pulsed-field gel electrophoresis profiles, but were different from other PRASEF described to date. Results demonstrate that penicillin-resistant, ampicillin-susceptible phenotype was already a reality in the 1990s in E. faecalis isolates in different Brazilian states, and some of these isolates were also imipenem- and piperacillin-resistant; therefore, internationally accepted susceptibility criteria cannot be applied to these isolates. According to pbp4 gene sequencing, this study suggests that a specific amino acid substitution in pbp4 gene found in all PRASEF analyzed is associated with penicillin resistance. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Heavy-chain isotype patterns of human antibody-secreting cells induced by Haemophilus influenzae type b conjugate vaccines in relation to age and preimmunity

DEFF Research Database (Denmark)

Barington, T; Juul, Lars; Gyhrs, A

1994-01-01

The influence of preexisting immunity on the heavy-chain isotypes of circulating antibody-secreting cells (AbSC) induced by vaccination with Haemophilus influenzae type b (Hib) capsular polysaccharide (HibCP) coupled to tetanus toxoid (TT) or diphtheria toxoid (DT) and by vaccination with TT or D...... of natural HibCP antibodies (r = 0.59; P = 0.00002). A possible role of natural exposure for Hib or cross-reactive bacteria on the mucosal surfaces in the shaping of the isotype response to HibCP conjugate vaccines is discussed....

Chancroid and Haemophilus ducreyi.

Science.gov (United States)

Morse, S A

1989-01-01

Haemophilus ducreyi is the causative agent of chancroid, one of the genital ulcerative diseases. H. ducreyi is the major cause of genital ulcer disease in Africa and Southeast Asia and is of increasing concern in the United States. Definitive diagnosis of chancroid requires the isolation and identification of H. ducreyi, but isolation of this organism is difficult and the available medium is not optimal for all strains. Fluorescent antibody and serologic tests are of limited value. In general, our knowledge of this organism is rather limited, and indeed, recent studies have questioned the placement of H. ducreyi in the genus Haemophilus. H. ducreyi has relatively few biochemical activities, and epidemiologic studies are limited because there are limited phenotypic markers available for strain typing. Specific virulence factors of H. ducreyi have yet to be identified. Antimicrobial resistance in H. ducreyi is of special concern, as this organism has acquired both gram-negative and gram-positive resistance determinants. In addition, some of these determinants can be mobilized and transferred to other Haemophilus species or to Neisseria gonorrhoeae. Images PMID:2650859

Immunoglobulin G Avidities in Infants in Mexico after Primary Immunization with Three Doses of Polyribosylribitol Phosphate-Tetanus Toxoid Haemophilus influenzae Type b Vaccine▿ †

Science.gov (United States)

Gómez-de-León, Patricia; Díaz-García, F. Javier; Villaseñor-Sierra, Alberto; Segura, Jorge; Carranza, Martha I.; Arredondo-Garcia, José Luis; Santos, José Ignacio

2008-01-01

Serum immunoglobulin G concentrations and avidities specific to Haemophilus influenzae type b (Hib) were measured in 208 children living in Guadalajara and Mexico City. Protective concentrations were found in 98.9% and 100.0% of participants, respectively. Geometric mean concentrations differed between both populations and/or among age groups. Mean avidities differed only among the 7- to 12-month-old children. Diphtheria-tetanus-whole-cell pertussis-hepatitis B-Hib primary vaccination seems to induce protection in Mexican children. PMID:18417667

Antiviral resistance and the control of pandemic influenza.

Directory of Open Access Journals (Sweden)

Marc Lipsitch

2007-01-01

Full Text Available The response to the next influenza pandemic will likely include extensive use of antiviral drugs (mainly oseltamivir, combined with other transmission-reducing measures. Animal and in vitro studies suggest that some strains of influenza may become resistant to oseltamivir while maintaining infectiousness (fitness. Use of antiviral agents on the scale anticipated for the control of pandemic influenza will create an unprecedented selective pressure for the emergence and spread of these strains. Nonetheless, antiviral resistance has received little attention when evaluating these plans.We designed and analyzed a deterministic compartmental model of the transmission of oseltamivir-sensitive and -resistant influenza infections during a pandemic. The model predicts that even if antiviral treatment or prophylaxis leads to the emergence of a transmissible resistant strain in as few as 1 in 50,000 treated persons and 1 in 500,000 prophylaxed persons, widespread use of antivirals may strongly promote the spread of resistant strains at the population level, leading to a prevalence of tens of percent by the end of a pandemic. On the other hand, even in circumstances in which a resistant strain spreads widely, the use of antivirals may significantly delay and/or reduce the total size of the pandemic. If resistant strains carry some fitness cost, then, despite widespread emergence of resistance, antivirals could slow pandemic spread by months or more, and buy time for vaccine development; this delay would be prolonged by nondrug control measures (e.g., social distancing that reduce transmission, or use of a stockpiled suboptimal vaccine. Surprisingly, the model suggests that such nondrug control measures would increase the proportion of the epidemic caused by resistant strains.The benefits of antiviral drug use to control an influenza pandemic may be reduced, although not completely offset, by drug resistance in the virus. Therefore, the risk of resistance

Origin of the diversity in DNA recognition domains in phasevarion associated modA genes of pathogenic Neisseria and Haemophilus influenzae.

Science.gov (United States)

Gawthorne, Jayde A; Beatson, Scott A; Srikhanta, Yogitha N; Fox, Kate L; Jennings, Michael P

2012-01-01

Phase variable restriction-modification (R-M) systems have been identified in a range of pathogenic bacteria. In some it has been demonstrated that the random switching of the mod (DNA methyltransferase) gene mediates the coordinated expression of multiple genes and constitutes a phasevarion (phase variable regulon). ModA of Neisseria and Haemophilus influenzae contain a highly variable, DNA recognition domain (DRD) that defines the target sequence that is modified by methylation and is used to define modA alleles. 18 distinct modA alleles have been identified in H. influenzae and the pathogenic Neisseria. To determine the origin of DRD variability, the 18 modA DRDs were used to search the available databases for similar sequences. Significant matches were identified between several modA alleles and mod gene from distinct bacterial species, indicating one source of the DRD variability was via horizontal gene transfer. Comparison of DRD sequences revealed significant mosaicism, indicating exchange between the Neisseria and H. influenzae modA alleles. Regions of high inter- and intra-allele similarity indicate that some modA alleles had undergone recombination more frequently than others, generating further diversity. Furthermore, the DRD from some modA alleles, such as modA12, have been transferred en bloc to replace the DRD from different modA alleles.

Comparative evaluation of culture and PCR for the detection and determination of persistence of bacterial strains and DNAs in the Chinchilla laniger model of otitis media.

Science.gov (United States)

Aul, J J; Anderson, K W; Wadowsky, R M; Doyle, W J; Kingsley, L A; Post, J C; Ehrlich, G D

1998-06-01

This study was designed to determine the persistence of culturable bacteria versus DNA in the presence of a middle ear effusion in a chinchilla model of otitis media. Cohorts of animals were either infected with an ampicillin-resistant Haemophilus influenzae strain or injected with a tripartite inoculum consisting of freeze-thawed Streptococcus pneumoniae; pasteurized Moraxella catarrhalis; and DNA from H influenzae. The H influenzae-infected animals displayed culture positivity and polymerase chain reaction positivity through day 35. In the chinchillas infected with the low-copy number inocula of S pneumoniae, DNA was not detectable after day 1 from the co-inoculated pasteurized M catarrhalis bacteria or the purified H influenzae DNA; however, amplifiable DNA from the live low-copy number bacteria persisted through day 21 even though they were not culture-positive past day 3. These results demonstrate that DNA, and DNA from intact but nonviable bacteria, does not persist in an amplifiable form for more than a day in the presence of an effusion; however, live bacteria, while not culturable, persist in a viable state for weeks.

Prevalence of beta-lactamases among ampicillin-resistant Escherichia coli and Salmonella isolated from food animals in Denmark

DEFF Research Database (Denmark)

Olesen, Inger; Hasman, Henrik; Aarestrup, Frank Møller

2004-01-01

The genetic background for beta-lactamase-mediated resistance to beta-lactam antibiotics was examined by PCR and sequencing in 160 ampicillin-resistant isolates (109 Escherichia coli and 51 Salmonella) obtained from healthy and diseased food animals in Denmark. Sequencing revealed three different...... leading to increased production of the AmpC beta-lactamase were demonstrated in 11 cefoxitin-resistant or intermediate E. coli isolates. Nine of these isolates did not contain any bla(TEM) genes, whereas the remaining two did. No genes encoding SHV or extended-spectrum beta-lactamases were detected. Two...

Antimicrobial susceptibility patterns of Haemophilus parasuis from pigs in the United Kingdom and Spain.

Science.gov (United States)

de la Fuente, A J Martín; Tucker, A W; Navas, J; Blanco, M; Morris, S J; Gutiérrez-Martín, C B

2007-02-25

A total of 30 British and 30 Spanish Haemophilus parasuis isolates were tested for their susceptibility to 19 of the antimicrobials currently used in swine practice with a broth microdilution method in order to know the emergence of resistance against these compounds in this porcine pathogen. All the British isolates were susceptible to penicillin, ceftiofur, erythromycin, tilmicosin, enrofloxacin, and florfenicol, and most of them were susceptible to the remaining antimicrobials (the highest resistance rate found was of 20% to neomycin). In contrast, all the Spanish isolates were susceptible exclusively to florfenicol, and high proportions of resistance were encountered for penicillin, ampicillin, oxytetracycline, erythromycin, tilmicosin, tiamulin and trimethoprim+sulphamethoxazole; in addition, a bimodal or multimodal distribution, or tailing of Spanish isolates over the MIC range was observed for clindamycin, sulphonamides and tylosine tartrate, suggesting the development of acquired resistance. In addition, several multiresistance patterns were found among the Spanish isolates, 23.3% of them being resistant to at least eight antimicrobials, the same rate as that encountered for those being susceptible to all antimicrobials tested. This study showed that in general British H. parasuis isolates are susceptible to antimicrobial agents routinely used for treatment of porcine respiratory diseases; however, the Spanish isolates need a more continuous surveillance of their susceptibility patterns.

Vaccination for the control of childhood bacterial pneumonia - Haemophilus influenzae type b and pneumococcal vaccines

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Diana C Otczyk

2013-01-01

Full Text Available Pneumonia in childhood is endemic in large parts of the world and in particular, in developing countries, as well as in many indigenous communities within developed nations. Haemophilus influenzae type b and Streptococcus pneumoniae conjugate vaccines are currently available against the leading bacterial causes of pneumonia.  The use of the vaccines in both industrialised and developing countries have shown a dramatic reduction in the burden of pneumonia and invasive disease in children.  However, the greatest threat facing pneumococcal conjugate vaccine effectiveness is serotype replacement.  The current vaccines provide serotype-specific, antibody–mediated protection against only a few of the 90+ capsule serotypes.  Therefore, there has been a focus in recent years to rapidly advance technologies that will result in broader disease coverage and more affordable vaccines that can be used in developing countries.  The next generation of pneumococcal vaccines have advanced to clinical trials.

Spontaneous Subconjunctival Abscess Because of Haemophilus influenzae

Science.gov (United States)

2010-07-01

any recent sexually transmitted diseases, vaginal discharge, or sores. Her past medical history included mild seasonal allergies and no history of...culture confirmed a nontypeable strain of H. influenzae. DISCUSSION H. influenzae is a small aerobic Gram-negative cocco- bacillus found mainly in the

Crystal Structures of Active Fully Assembled Substrate- and Product-Bound Complexes of UDP-N-Acetylmuramic Acid:l-Alanine Ligase (MurC) from Haemophilus influenzae

OpenAIRE

Mol, Clifford D.; Brooun, Alexei; Dougan, Douglas R.; Hilgers, Mark T.; Tari, Leslie W.; Wijnands, Robert A.; Knuth, Mark W.; McRee, Duncan E.; Swanson, Ronald V.

2003-01-01

UDP-N-acetylmuramic acid:l-alanine ligase (MurC) catalyzes the addition of the first amino acid to the cytoplasmic precursor of the bacterial cell wall peptidoglycan. The crystal structures of Haemophilus influenzae MurC in complex with its substrate UDP-N-acetylmuramic acid (UNAM) and Mg2+ and of a fully assembled MurC complex with its product UDP-N-acetylmuramoyl-l-alanine (UMA), the nonhydrolyzable ATP analogue AMPPNP, and Mn2+ have been determined to 1.85- and 1.7-Å resolution, respective...

Nontypeable Haemophilus influenzae in chronic obstructive pulmonary disease and lung cancer

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Seyed Javad Moghaddam

2011-01-01

Full Text Available Seyed Javad Moghaddam1, Cesar E Ochoa1,2, Sanjay Sethi3, Burton F Dickey1,41Department of Pulmonary Medicine, the University of Texas MD Anderson Cancer Center, Houston, TX, USA; 2Tecnológico de Monterrey School of Medicine, Monterrey, Nuevo León, Mexico; 3Department of Medicine, University at Buffalo, State University of New York, Buffalo, NY, USA; 4Center for Inflammation and Infection, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USAAbstract: Chronic obstructive pulmonary disease (COPD is predicted to become the third leading cause of death in the world by 2020. It is characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lungs to noxious particles and gases, most commonly cigarette smoke. Among smokers with COPD, even following withdrawal of cigarette smoke, inflammation persists and lung function continues to deteriorate. One possible explanation is that bacterial colonization of smoke-damaged airways, most commonly with nontypeable Haemophilus influenzae (NTHi, perpetuates airway injury and inflammation. Furthermore, COPD has also been identified as an independent risk factor for lung cancer irrespective of concomitant cigarette smoke exposure. In this article, we review the role of NTHi in airway inflammation that may lead to COPD progression and lung cancer promotion.Keywords: COPD, NTHi, inflammation

[Optimized isolation and purification of non-typeable Haemophilus influenzae Haps protein].

Science.gov (United States)

Li, Wan-yi; Kuang, Yu; Li, Ming-yuan; Yang, Yuan; Jiang, Zhong-hua; Yao, Feng; Chen, Chang-chun

2007-12-01

To optimize the isolation and purification conditions for Hap(s) protein of non-typeable Haemophilus influenzae. Hap(s) protein was purified by ammonium sulfate precipitation, dialysis desalting and Hitrap weak cation exchange columns of CM Sepharose Fast Flow. The condition of the elution was optimized for pH and ionic strength, the absorbance at 280 nm of the elution samples were detected, and the targeted protein band in the collected samples was observed by SDS-PAGE electrophoresis. The Hitrap ion exchange column was eluted with buffer 1, which resulted in a baseline distribution of absorbance at 280 nm. Buffer 2 elution of the column resulted in the presence of peak absorbance with trails, which was identified to be constituted by some low molecular weight bands by subsequent SDS-PAGE. In serial column elution with buffer 3 with different ionic strength, a peak absorbance was observed with the ionic strength of 100 mmol/L NaCl, and SDS-PAGE confirmed that the peak was generated by the target protein. No obvious peaks or bands in SDS-PAGE occurred with the other ionic strengths. The pH of the buffer only affect the elution of the irrelevant proteins rather than the Hap(s) protein, and elution with the buffer containing 100 mmol/L NaCl can be optimal for eluting the Hap(s) protein.

Mutation of Haemophilus influenzae transforming DNA in vitro with near-ultraviolet radiation: action spectrum

Energy Technology Data Exchange (ETDEWEB)

Cabrera-Juarez, E; Setlow, J K [Escuela Nacional de Ciencias Biologicas, Mexico City. Dept. de Bioquimica; Oak Ridge National Lab., Tenn. (USA). Biology Div.)

1976-05-01

Mutations were produced in purified transforming DNA from Haemophilus influenzae by near UV radiation and were assayed as mutants among cells transformed with irradiated DNA. The maximum efficiency of mutation induction was at around 334 nm, and the efficiency dropped off steeply at lower and higher wavelengths. The difference between the action spectrum for mutation and that for the oxygen-independent inactivation of transforming DNA, which had a shoulder at 365 nm, indicates that there are different lesions involved in the inactivating and mutagenic effects of near-UV. The presence of histidine during irradiation enhanced the mutagenic effect at 334 and 365 nm, although it protected against inactivation at 365 nm. The effective near-UV wavelengths for in vitro mutation are to some extent the same as the effective wavelengths for mutation in vivo reported previously. These findings indicate that mutations are produced in vivo by near-UV with DNA as the primary target molecule rather than by a secondary non-photochemical reaction between DNA and some other cell component.

Modeling the growth dynamics of multiple Escherichia coli strains in the pig intestine following intramuscular ampicillin treatment

DEFF Research Database (Denmark)

Ahmad, Amais; Zachariasen, Camilla; Christiansen, Lasse Engbo

2016-01-01

using a mathematical model to simulate the competitive growth of E. coli strains in a pig intestine under specified plasma concentration profiles of ampicillin. Results : In vitro growth results demonstrated that the resistant strains did not carry a fitness cost for their resistance, and that the most...... with ampicillin resistance in E. coli. Besides dosing factors, epidemiological factors (such as number of competing strains and bacterial excretion) influenced resistance development and need to be considered further in relation to optimal treatment strategies. The modeling approach used in the study is generic......Background : This study evaluated how dosing regimen for intramuscularly-administered ampicillin, composition of Escherichia coli strains with regard to ampicillin susceptibility, and excretion of bacteria from the intestine affected the level of resistance among Escherichia coli strains...

Immunogenicity of a 2-dose priming and booster vaccination with the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine

DEFF Research Database (Denmark)

Silfverdal, Sven Arne; Høgh, Birthe; Bergsaker, Marianne Riise

2009-01-01

BACKGROUND: The immunogenicity of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D-conjugate vaccine (PHiD-CV) was determined following a simplified 2-dose priming and the more commonly employed 3-dose priming both followed by a booster dose. METHODS: A total of 351 healthy....... RESULTS: Depending on the serotype, the percentages of subjects reaching the ELISA antibody threshold of 0.2 microg/mL were 92.8% to 98.0% following 2 primary doses and 96.1% to 100% following 3 primary doses except for serotype 6B (55.7% and 63.1%, respectively) and serotype 23F (69.3% and 77...

Vigilancia de los serotipos y susceptibilidad antimicrobiana de Haemophilus influenzae en Colombia, 1994-2002.

Directory of Open Access Journals (Sweden)

María Victoria Ovalle

2003-06-01

Full Text Available La enfermedad invasora causada por Haemophilus influenzae, serotipo b, ha sido una de las mayores causas de morbilidad y mortalidad en la población infantil; afortunadamente, en algunos países con amplia cobertura de la vacuna conjugada esta situación ha cambiado. En 1994 se inició en el Grupo de Microbiología un programa de vigilancia de la susceptibilidad antimicrobiana y de los serotipos de aislamientos invasores de H. influenzae, remitidos por los hospitales y Laboratorios de Salud Pública del país como componente de los programas de vigilancia en red de infección respiratoria aguda y meningitis bacteriana aguda. El objetivo de este trabajo fue determinar la evolución de los serotipos y los patrones de susceptibilidad antimicrobiana de los aislamientos invasores de H. influenzae obtenidos de 1994 al 2002 y realizar un nuevo análisis sobre el impacto de la vacuna conjugada de H. influenzae, serotipo b, en Colombia. De 1994 a 2002 se han estudiado 683 aislamientos; 379 (55,5% de pacientes del género masculino; 370 (54,2% de menores de 1 año; 227 (33,2% de 1 a 5 años; 19 (2,8% de 6 a 14 años; 38 (5,6% de mayores de 14 años, y de 29 (4,2% no se tenía el dato de la edad; 493 (72,2% fueron recuperados de pacientes con meningitis, 181 (26,5% de neumonía y 9 (0,9% de otras enfermedades. El 85,1% de los aislamientos fueron H. influenzae, serotipo b, 12,9% no capsulares y 2,0% de otros serotipos (10 a, 1 d, 1 e y 2 f. Del total de aislamientos, 12% fueron productores de beta-lactamasa; 13,9%, resistentes a ampicilina; 12,7%, a trimetoprim sulfametoxazol (SXT; 5,4%, a cloranfenicol, y 1% a cefuroxima; todos fueron sensibles a ceftriaxona. Durante este período se observó un incremento en la resistencia de los aislamientos a SXT (5% al 13%, pero la diferencia no fue estadísticamente significativa (p=0,1. Con la vigilancia se pudo determinar una disminución significativa de los casos de meningitis en los menores de 1 año y en el

Multiplex quantitative PCR for detection of lower respiratory tract infection and meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis.

Science.gov (United States)

Abdeldaim, Guma M K; Strålin, Kristoffer; Korsgaard, Jens; Blomberg, Jonas; Welinder-Olsson, Christina; Herrmann, Björn

2010-12-03

Streptococcus pneumoniae and Haemophilus influenzae cause pneumonia and as Neisseria meningitidis they are important agents of meningitis. Although several PCR methods have been described for these bacteria the specificity is an underestimated problem. Here we present a quantitative multiplex real-time PCR (qmPCR) for detection of S. pneumoniae (9802 gene fragment), H. influenzae (omp P6 gene) and N. meningitidis (ctrA gene). The method was evaluated on bronchoalveolar lavage (BAL) samples from 156 adults with lower respiratory tract infection (LRTI) and 31 controls, and on 87 cerebrospinal fluid (CSF) samples from meningitis patients. The analytical sensitivity was not affected by using a combined mixture of reagents and a combined DNA standard (S. pneumoniae/H. influenzae/N. meningitidis) in single tubes. By blood- and BAL-culture and S. pneumoniae urinary antigen test, S. pneumoniae and H. influenzae were aetiological agents in 21 and 31 of the LTRI patients, respectively. These pathogens were identified by qmPCR in 52 and 72 of the cases, respectively, yielding sensitivities and specificities of 95% and 75% for S. pneumoniae, and 90% and 65% for H. influenzae, respectively. When using a cut-off of 10⁵ genome copies/mL for clinical positivity the sensitivities and specificities were 90% and 80% for S. pneumoniae, and 81% and 85% for H. influenzae, respectively. Of 44 culture negative but qmPCR positive for H. influenzae, 41 were confirmed by fucK PCR as H. influenzae. Of the 103 patients who had taken antibiotics prior to sampling, S. pneumoniae and H. influenzae were identified by culture in 6% and 20% of the cases, respectively, and by the qmPCR in 36% and 53% of the cases, respectively.In 87 CSF samples S. pneumoniae and N. meningitidis were identified by culture and/or 16 S rRNA in 14 and 10 samples and by qmPCR in 14 and 10 samples, respectively, giving a sensitivity of 100% and a specificity of 100% for both bacteria. The PCR provides increased

Multiplex quantitative PCR for detection of lower respiratory tract infection and meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis

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Welinder-Olsson Christina

2010-12-01

Full Text Available Abstract Background Streptococcus pneumoniae and Haemophilus influenzae cause pneumonia and as Neisseria meningitidis they are important agents of meningitis. Although several PCR methods have been described for these bacteria the specificity is an underestimated problem. Here we present a quantitative multiplex real-time PCR (qmPCR for detection of S. pneumoniae (9802 gene fragment, H. influenzae (omp P6 gene and N. meningitidis (ctrA gene. The method was evaluated on bronchoalveolar lavage (BAL samples from 156 adults with lower respiratory tract infection (LRTI and 31 controls, and on 87 cerebrospinal fluid (CSF samples from meningitis patients. Results The analytical sensitivity was not affected by using a combined mixture of reagents and a combined DNA standard (S. pneumoniae/H. influenzae/N. meningitidis in single tubes. By blood- and BAL-culture and S. pneumoniae urinary antigen test, S. pneumoniae and H. influenzae were aetiological agents in 21 and 31 of the LTRI patients, respectively. These pathogens were identified by qmPCR in 52 and 72 of the cases, respectively, yielding sensitivities and specificities of 95% and 75% for S. pneumoniae, and 90% and 65% for H. influenzae, respectively. When using a cut-off of 105 genome copies/mL for clinical positivity the sensitivities and specificities were 90% and 80% for S. pneumoniae, and 81% and 85% for H. influenzae, respectively. Of 44 culture negative but qmPCR positive for H. influenzae, 41 were confirmed by fucK PCR as H. influenzae. Of the 103 patients who had taken antibiotics prior to sampling, S. pneumoniae and H. influenzae were identified by culture in 6% and 20% of the cases, respectively, and by the qmPCR in 36% and 53% of the cases, respectively. In 87 CSF samples S. pneumoniae and N. meningitidis were identified by culture and/or 16 S rRNA in 14 and 10 samples and by qmPCR in 14 and 10 samples, respectively, giving a sensitivity of 100% and a specificity of 100% for both

GyrA and/or ParC alterations of Haemophilus influenzae strains isolated from the urethra of men with acute urethritis.

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Kondo, Hiromi; Ito, Shin; Hatazaki, Kyoko; Horie, Kengo; Nakane, Keita; Mizutani, Kosuke; Tsuchiya, Tomohiro; Yasuda, Mitsuru; Yokoi, Shigeaki; Nakano, Masahiro; Deguchi, Takashi

2018-03-01

Of 73 clinical strains of Haemophilus influenzae isolated from the urethra of men with urogenital infections, we enrolled 6 strains (8.2%) with levofloxacin (LVFX) minimum inhibitory concentrations (MICs) of ≥0.03 μg/ml in this study. All the strains were isolated from non-gonococcal urethritis (NGU). We amplified the quinolone resistance-determining region of the gyrA gene and the analogous region of the parC gene from bacterial DNAs by PCR and sequenced the PCR products. Two strains with a LVFX MIC of 0.03 μg/ml had an amino acid change of Asp88 to Gly in GyrA. One with a LVFX MIC of 0.06 μg/ml had a change of Asp88 to Tyr in GyrA. Two with respective LVFX MICs of 0.12 and 0.25 μg/ml had a change of Ser84 to Leu in GyrA. One with a LVFX MIC of 1 μg/ml had changes of Ser84 to Leu in GyrA and of Ser84 to Ile in ParC. Multilocus sequence typing showed two strains with a change of Asp88 to Gly in GyrA had the same sequence type, but the others had sequence types different from each other. Single amino acid changes in GyrA alone or single changes in both GyrA and ParC could contribute to decreased susceptibility to fluoroquinolones in H. influenzae isolates from NGU. Most of the isolates with GyrA and/or ParC alterations would be multiclonal. The prevalence of such isolates would be relatively low, and they would still be susceptible to fluoroquinolones commonly prescribed for treatment of NGU. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Unexpected effects of absorbed normal rabbit serum and bovine serum albumin on survival of Haemophilus influenzae type b in the infant rat.

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Loeb, M R

1988-01-01

In the course of using the infant rat model to determine the ability of various rabbit antisera to protect against challenge by Haemophilus influenzae type b we made two unexpected observations. In these experiments 4-day-old rats were inoculated s.c. on the dorsum with either rabbit serum or physiological buffers (sham serum) and then were challenged the next day with H. influenzae type b injected i.p. Bacteremia, as a marker for disease, was measured 24 h later on day 6. We observed the following. (i) Pre-immune, i.e., normal rabbit serum, containing minimal levels of antibodies to outer membrane proteins and depleted of antibodies to capsule and lipopolysaccharide, nevertheless significantly (P less than 0.01) protected the rats from challenge with H. influenzae type b when compared to a sham inoculation of buffer; (ii) In the absence of a serum inoculation on day 4 (a buffer was used as a sham serum inoculation), the levels of bacteremia obtained after inoculation with bacteria on day 5 depended upon the composition of the buffer in which the H. influenzae inoculum was suspended. Use of phosphate buffered saline (PBS) resulted in higher levels of bacteremia than PBS containing 0.5% bovine serum albumin (PBS-BSA) (P less than 0.001), i.e. the BSA apparently acted to protect the rats from H. influenzae infection. In fact the use of PBS-BSA as an inoculum buffer masked the protective effect noted above of the absorbed normal rabbit serum.

Comparative transcriptional profiling of tildipirosin-resistant and sensitive Haemophilus parasuis.

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Lei, Zhixin; Fu, Shulin; Yang, Bing; Liu, Qianying; Ahmed, Saeed; Xu, Lei; Xiong, Jincheng; Cao, Jiyue; Qiu, Yinsheng

2017-08-08

Numerous studies have been conducted to examine the molecular mechanism of Haemophilus parasuis resistance to antibiotic, but rarely to tildipirosin. In the current study, transcriptional profiling was applied to analyse the variation in gene expression of JS0135 and tildipirosin-resistant JS32. The growth curves showed that JS32 had a higher growth rate but fewer bacteria than JS0135. The cell membranes of JS32 and a resistant clinical isolate (HB32) were observed to be smoother than those of JS0135. From the comparative gene expression profile 349 up- and 113 downregulated genes were observed, covering 37 GO and 63 KEGG pathways which are involved in biological processes (11), cellular components (17), molecular function (9), cellular processes (1), environmental information processing (4), genetic information processing (9) and metabolism (49) affected in JS32. In addition, the relative overexpression of genes of the metabolism pathway (HAPS_RS09315, HAPS_RS09320), ribosomes (HAPS_RS07815) and ABC transporters (HAPS_RS10945) was detected, particularly the metabolism pathway, and verified with RT-qPCR. Collectively, the gene expression profile in connection with tildipirosin resistance factors revealed unique and highly resistant determinants of H. parasuis to macrolides that warrant further attention due to the significant threat of bacterial resistance.

Recurrent meningitis due to pneumococci and non-typable Haemophilus influenzae in a child with a Mondini malformation.

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Valmari, P; Palva, A

1986-01-01

An eight-year-old boy with a congenital inner ear malformation and recurrent otitis media had three episodes of bacteriologically confirmed meningitis within seven months. The first episode was caused by pneumococci, the other two by non-typable Haemophilus influenzae. All episodes were characterized by an abrupt onset. The CSF cultures were positive within 0.5 to 12 hours after the onset of symptoms. Despite misleading laboratory studies, surgical exploration revealed a CSF fistula associated to the inner ear anomaly. No further episodes occurred after the fistula was closed. Careful roentgenographic evaluation, including recently introduced special computed tomography (CT) methods, is indicated in recurrent meningitis. In addition, such evaluations should be considered even after the first episode, when special clinical features suggest a CSF fistula. Such features include an extremely rapid onset and detection of common non-invasive bacteria as causative agents, as illustrated by the present case.

Nontypeable Haemophilus influenzae induces sustained lung oxidative stress and protease expression.

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Paul T King

Full Text Available Nontypeable Haemophilus influenzae (NTHi is a prevalent bacterium found in a variety of chronic respiratory diseases. The role of this bacterium in the pathogenesis of lung inflammation is not well defined. In this study we examined the effect of NTHi on two important lung inflammatory processes 1, oxidative stress and 2, protease expression. Bronchoalveolar macrophages were obtained from 121 human subjects, blood neutrophils from 15 subjects, and human-lung fibroblast and epithelial cell lines from 16 subjects. Cells were stimulated with NTHi to measure the effect on reactive oxygen species (ROS production and extracellular trap formation. We also measured the production of the oxidant, 3-nitrotyrosine (3-NT in the lungs of mice infected with this bacterium. NTHi induced widespread production of 3-NT in mouse lungs. This bacterium induced significantly increased ROS production in human fibroblasts, epithelial cells, macrophages and neutrophils; with the highest levels in the phagocytic cells. In human macrophages NTHi caused a sustained, extracellular production of ROS that increased over time. The production of ROS was associated with the formation of macrophage extracellular trap-like structures which co-expressed the protease metalloproteinase-12. The formation of the macrophage extracellular trap-like structures was markedly inhibited by the addition of DNase. In this study we have demonstrated that NTHi induces lung oxidative stress with macrophage extracellular trap formation and associated protease expression. DNase inhibited the formation of extracellular traps.

Non-epitope-specific suppression of the antibody response to Haemophilus influenzae type b conjugate vaccines by preimmunization with vaccine components

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Barington, T; Skettrup, M; Juul, L

1993-01-01

children and adults. Despite its potential importance, the possible influence of preexisting immunity to the components of such conjugates on the vaccination response in humans has been addressed by few studies. To study this issue, we randomized 82 healthy adult volunteers into six groups and vaccinated......Recently, conjugate vaccines containing Haemophilus influenzae type b capsular polysaccharide (HibCP) coupled to protein carriers were introduced for use in infants and certain adult risk groups. Similar conjugate vaccines against other capsulated bacteria are currently under development for both......CP-TT, P = 0.00002; HibCP-TT and then HibCP-DT, P = 0.06) as well as to HibCP itself. Possible mechanisms behind this non-epitope-specific suppression and its relevance for vaccine development are discussed....

Antimicrobial Resistance Patterns of Aerobic Organisms in Patients With Chronic Rhinosinusitis in Hamadan, Iran

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Farahani

2014-08-01

Full Text Available Background Although effective strategies have been presented for preventing the spread of antibiotic resistance in Iran, recent reports have revealed increasing antibiotic resistance among children and adults. Objectives In the present study, we tried to provide a clear view of the antibiotic resistance status of aerobic organism as the most prevalent organism in patients with rhinosinusitis in Hamadan, Iran. Patients and Methods A cross-sectional study was conducted on 216 consecutive patients referred to otolaryngology clinics of Imam Khomeini and Besat University hospitals in Hamadan with clinical and radiological manifestations of chronic rhinosinusitis. Two specimens were taken from each patient; one from the affected maxillary sinus by aspiration and another from the middle meatus and nasopharynx by swabbing. Antibiotic susceptibility was tested by Kirby Bauer’s method; distributions of the isolates from middle meatus, nasopharynx and sinus were determined and the results of susceptibility test were analyzed. Results Among the aerobic organism from meatus and oropharynx, the most frequent isolated strains were alpha-hemolytic Streptococcus (15.4%, followed by coagulase-negative Staphylococcus (14.6%, and Branhamella catarrhalis (13.2%, and the most prevalent isolated strains from sinus were S. aureus (19.1%, Klebsiella pneumonia (16.4%, and B. catarrhalis (15.6%, respectively. The highest antibiotic susceptibility was detected to ciprofloxacin and ceftriaxone in most of the strains; susceptibility to ciprofloxacin ranged from 76.7% (for Pseudomonas aeruginosa to 100% (for Escherichia coli and Haemophilus influenza; susceptibility to ceftriaxone ranged from 71.4% (for Acinetobacter baumannii to 100% (for S. pneumonia, Corynebacterium diphtheria, and H. influenza. Besides, regardless of strain, the highest resistance was mostly detected to penicillin (ranging from 33.3% to 91.7%, and to ampicillin (ranging from 38.4% to 83.7%. Conclusions

[Distribution and drug resistance of the pathogenic bacteria from sputum specimens of 1 125 children with tracheo bronchial foreign bodies].

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Wen, Xin; Su, Jinzhu; Cui, Li; Wang, Juan; Zuo, Lujie

2015-02-01

To analyze the distribution and drug susceptibility of the pathogenic bacteria in the airway secretions in children with tracheobronchial foreign bodies so as to assist physicians in clinical prescription. Sputum specimens of 1 125 children with tracheobronchial foreign bodies were collected in removal of the foreign bodies by rigid bronchoscope, and the drug susceptibility test was performed. Pathogenic bacteria were detected in 218 (19.4%) of 1 125 sputum specimens. Among the pathogenic bacteria, 126 (57.79%) strains were gram-negative bacilli, consisting of 76 (34.86%) strains of Haemophilus influenzae, 10 (4.59%) strains of Escherichia coli, 7 (3.21%) strains of Sewer enterobacter, 7 (3.21%) strains of Pseudomonas aeruginosa, and 6 (2.75%) strains of Klebsiella bacillus; and 92 (42.21%) strains were gram-positive bacilli, consisting of 80 (36.69%) strains of Streptococcus pneumonia and 10 (4.59%) strains of Escherichia coli. Most of detected gram-negative bacilli were highly sensitive to cefepime, ceftazidine, imipenem and amikacin, no strains were resistant to meropenem and ciprofloxacin. None of the detected gram-positive bacilli were resistant to cefepime, vancomycin, levofloxacin and teicoplanin. The Haemophilus influenzae of gram-negative bacilli and the Streptococcus pneumonia of gram-positive bacilli are the main pathogenic bacteria existing in the airway secretions of children with tracheobronchial foreign bodies. The Haemophilus influenzae were highly sensitive to cephalosporin, imipenem and amikacin, and the Streptococcus pneumonia to cefepime, vancomycin, levofloxacin and teicoplanin.

Beta- Lactam Antibiotics Stimulate Biofilm Formation in Non-Typeable Haemophilus influenzae by Up-Regulating Carbohydrate Metabolism

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Wu, Siva; Li, Xiaojin; Gunawardana, Manjula; Maguire, Kathleen; Guerrero-Given, Debbie; Schaudinn, Christoph; Wang, Charles; Baum, Marc M.; Webster, Paul

2014-01-01

Non-typeable Haemophilus influenzae (NTHi) is a common acute otitis media pathogen, with an incidence that is increased by previous antibiotic treatment. NTHi is also an emerging causative agent of other chronic infections in humans, some linked to morbidity, and all of which impose substantial treatment costs. In this study we explore the possibility that antibiotic exposure may stimulate biofilm formation by NTHi bacteria. We discovered that sub-inhibitory concentrations of beta-lactam antibiotic (i.e., amounts that partially inhibit bacterial growth) stimulated the biofilm-forming ability of NTHi strains, an effect that was strain and antibiotic dependent. When exposed to sub-inhibitory concentrations of beta-lactam antibiotics NTHi strains produced tightly packed biofilms with decreased numbers of culturable bacteria but increased biomass. The ratio of protein per unit weight of biofilm decreased as a result of antibiotic exposure. Antibiotic-stimulated biofilms had altered ultrastructure, and genes involved in glycogen production and transporter function were up regulated in response to antibiotic exposure. Down-regulated genes were linked to multiple metabolic processes but not those involved in stress response. Antibiotic-stimulated biofilm bacteria were more resistant to a lethal dose (10 µg/mL) of cefuroxime. Our results suggest that beta-lactam antibiotic exposure may act as a signaling molecule that promotes transformation into the biofilm phenotype. Loss of viable bacteria, increase in biofilm biomass and decreased protein production coupled with a concomitant up-regulation of genes involved with glycogen production might result in a biofilm of sessile, metabolically inactive bacteria sustained by stored glycogen. These biofilms may protect surviving bacteria from subsequent antibiotic challenges, and act as a reservoir of viable bacteria once antibiotic exposure has ended. PMID:25007395

Characterization of Hospital-Associated Lineages of Ampicillin-Resistant Enterococcus faecium from Clinical Cases in Dogs and Humans

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Cindy-Love eTremblay

2013-08-01

Full Text Available Ampicillin-resistant Enterococcus faecium (ARE has rapidly emerged worldwide and is one of the most important nosocomial pathogens. However, very few reports are available on ARE isolates from canine clinical cases. The objective of this study was to characterize ARE strains of canine clinical origin from a veterinary teaching hospital in Canada and to compare them with human strains. Ten ARE strains from dogs and humans were characterized by multilocus sequence typing (MLST, pulsed field gel electrophoresis (PFGE, antibiotic susceptibility and biofilm activities, presence of rep-families, CRISPR-cas and putative virulence genes. All ARE strains (n = 10 were resistant to ciprofloxacin and lincomycin. Resistances to tetracycline (n = 6, macrolides (n = 6, and to high concentrations of gentamicin, kanamycin and streptomycin (n = 5 were also observed. Canine ARE isolates were found to be susceptible to vancomycin whereas resistance to this antibiotic was observed in human strains. Ampicillin resistance was linked to PBP5 showing mutations at 25 amino acid positions. Fluoroquinolone resistance was attributable to ParC, GyrA, and GyrB mutations. Data demonstrated that all canine ARE were acm (collagen binding protein-positive and that most harbored the efaAfm gene, encoding for a cell wall adhesin. Biofilm formation was observed in two human strains but not in canine strains. Two to five rep-families were observed per strain but no CRISPR sequences were found. A total of six STs (1, 18, 65, 202, 205, and 803 were found with one belonging to a new ST (ST803. These STs were identical or closely related to human hospital-associated lineages. This report describes for the first time the characterization of canine ARE hospital-associated strains in Canada and also supports the importance of prudent antibiotic use in veterinary medicine to avoid zoonotic spread of canine ARE.

Oseltamivir resistance among influenza viruses: surveillance in northern Viet Nam, 2009-2012.

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Hoang Vu, Mai-Phuong; Nguyen, Co Thach; Nguyen, Le Khanh Hang; Nguyen, Thi Kim Phuong; Le, Quynh Mai

2013-01-01

Antiviral resistance has been reported in seasonal influenza A viruses and avian influenza A(H5N1) viruses in Viet Nam, raising concerns about the efficacy of treatment. We analysed specimens from two sources during the period 2009-2012: influenza-positive samples from influenza-like illness patients at sentinel clinics in northern Viet Nam and isolates from patients with confirmed A(H5N1) infections. Pyrosequencing was used to detect mutations: H275Y [for A(H1N1) and A(H5N1)], E119V [for A(H3N2)] and I117V [for A(H5N1)]. A neuraminidase inhibition assay was used to determine the Inhibitory Concentration 50 (IC₅₀) values for all influenza A and B isolates. There were 341 influenza A positive samples identified; influenza A(H1N1)pdm09 was identified most frequently (n = 215). In 2009, oseltamivir resistance was observed in 100% (19 of 19) of seasonal A(H1N1) isolates and 1.4% (3/215) of A(H1N1)pdm09 isolates. This H275Y mutation was not found in influenza subtypes A(H5N1) or A(H3N2) isolates. In Viet Nam, seasonal and A(H5N1) influenza vaccines are not currently available; thus, effective treatment is required. The presence of oseltamivir-resistant viruses is therefore a concern. Active surveillance for oseltamivir resistance among influenza viruses circulating in Viet Nam should be continued.

TOC-39, a novel parenteral broad-spectrum cephalosporin with excellent activity against methicillin-resistant Staphylococcus aureus.

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Hanaki, H; Akagi, H; Masaru, Y; Otani, T; Hyodo, A; Hiramatsu, K

1995-01-01

TOC-39, a new parenteral cephalosporin, is a hydroxyimino-type cephem antibiotic with vinylthio-pyridyl moiety at the 3 position. TOC-39 was evaluated for antibacterial activity against various clinically isolated strains. TOC-39 had excellent activity, stronger than that of methicillin, oxacillin, the cephalosporins tested, imipenem, gentamicin, minocycline, tobramycin, ofloxacin, and ciprofloxacin against methicillin-resistant Staphylococcus aureus (MRSA) and had an MIC comparable to that of vancomycin (the MICs of TOC-39 and vancomycin for 90% of the strains tested were 3.13 and 1.56 micrograms/ml, respectively). Against Enterococcus faecalis strains, which are resistant to cephalosporins, TOC-39 was twice as active as ampicillin. Against methicillin-susceptible S. aureus, coagulase-negative Staphylococcus spp., and Streptococcus pneumoniae, TOC-39 was twice as active as or more active than cefotiam, ceftazidime, flomoxef, and cefpirome. Against Streptococcus pyogenes, TOC-39 was superior to cefotiam, ceftazidime, and flomoxef and was similar to cefpirome. In addition, the activity of TOC-39 was equal to or greater than that of cefotiam, ceftazidime, flomoxef, and cefpirome against Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Morganella morganii. In terms of bactericidal effect against MRSA, TOC-39 was superior to vancomycin. No mutant resistant to TOC-39 or vancomycin was obtained from susceptible MRSA strains. In murine systemic infection models, TOC-39 showed potent activity against S. aureus and E. coli. Against highly MRSA, the activity of TOC-39 was comparable to that of vancomycin. PMID:7625799

Epidemiology of paediatric meningitis in central Côte d'Ivoire after the implementation of Haemophilus influenzae type b vaccination.

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Touré, Fidèle S; Kouame, Samson; Tia, Honoré; Monemo, Pacôme; Cissé, Amadou; Diané, Bamourou; Becker, Sören L; Akoua-Koffi, Chantal

2017-07-01

Infectious meningitis accounts for enormous morbidity worldwide, but there is a paucity of data on its regional epidemiology in resource-constrained settings of sub-Saharan Africa. Here, we present a study on the aetiology of paediatric meningitis in central Côte d'Ivoire. Between June 2012 and December 2013, all cerebrospinal fluid (CSF) samples drawn at the University Teaching Hospital Bouaké were examined for the presence of bacterial and fungal pathogens. A causative agent was detected in 31 out of 833 CSF specimens (3.7%), with the most prevalent pathogens being Streptococcus pneumoniae (n=15) and Neisseria meningitidis (n=5). With the exception of neonates, these two bacteria were the most common agents in all age groups. Of note, only a single case of Haemophilus influenzae meningitis was detected. Hence, this study reports a considerable shift in the epidemiology of paediatric meningitis in central Côte d'Ivoire. Following the implementation of a nation-wide childhood vaccination programme against H. influenzae type b, this pathogen was much less frequently reported than in previous studies. The integration of specific vaccines against S. pneumoniae and N. meningitidis into the childhood vaccination programme in Côted'Ivoire holds promise to further reduce the burden due to infectious meningitis.

Safety and reactogenicity of the combined diphtheria-tetanus-acellular pertussis-inactivated poliovirus-Haemophilus influenzae type b (DTPa-IPV/Hib) vaccine in healthy Vietnamese toddlers: An open-label, phase III study.

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Anh, Dang Duc; Van Der Meeren, Olivier; Karkada, Naveen; Assudani, Deepak; Yu, Ta-Wen; Han, Htay Htay

2016-03-03

The introduction of combination vaccines plays a significant role in increasing vaccine acceptance and widening vaccine coverage. Primary vaccination against diphtheria, tetanus, pertussis, poliomyelitis and Haemophilus influenza type b (Hib) diseases has been implemented in Vietnam. In this study we evaluated the safety and reactogenicity of combined diphtheria-tetanus-pertussis-inactivated polio (DTPa-IPV)/Hib vaccine when administered as a booster dose in 300 healthy Vietnamese children Vietnamese children aged <2 years.

Polymerase Chain Reaction, Bacteriologic Detection and Antibiogram of Bacteria Isolated from Otitis Media with Effusion in Children, Shiraz, Iran

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Mahmood Shishegar

2011-12-01

Full Text Available Background: Otitis media with effusion is one of the leading causes of hearing loss in children. Effective treatment of effusion in the middle ear requires appropriate empirical treatment and characterization of responsible pathogens. Objective of the present study was to detect pathogens in clinical samples from patients with otitis media with effusion in our area and to determine the sensitivity profile of isolated organisms to commonly used antibiotics. Methods: Sixty three samples of middle ear effusion were aseptically obtained from 36 children, who had been treated up to at least two weeks before sampling. They were analyzed using standard bacteriological and multiplex polymerase chain reaction (PCR assays. Antibiotic susceptibility tests were also performed. Results: PCR analysis showed that DNA of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were present in 60 (95.2% of the samples. The culture-positive effusion for Streptococcus Pneumoniae, HaemophilusInfluenzae and Moraxella catarrhalis was 34.9%. Almost all isolates of Streptococcus pneumoniaee were sensitive to ciprofloxacin and erythromycin, and none of them was sensitive to co-trimoxazole. None of H. Influenzae isolates was sensitive to erythromycin, cefixim, co-trimoxazole, ampicillin and amoxicillin. None of M. Catarrhalis isolates was sensitive to ceftriaxone, co-trimoxazole, ampicillin and amoxicillin. Conclusion: Compared with other studies using PCR method, the number of H. influenza isolates was in higher in the present study (95.2%. Antibiotic sensitivity profiles of pathogens isolated in this study were different from others. Thus, we can determine empirical antibiotic therapy based on sensi-tivity profile in our geographic area.

Erythromycin and azithromycin transport into Haemophilus influenzae ATCC 19418 under conditions of depressed proton motive force (delta mu H)

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Capobianco, J.O.; Goldman, R.C. (Abbott Laboratories, IL (USA))

1990-09-01

The effect of collapsing the electrochemical proton gradient (delta mu H) on ({sup 3}H)erythromycin and ({sup 14}C)azithromycin transport in Haemophilus influenzae ATCC 19418 was studied. The proton gradient and membrane potential were determined from the distribution of (2-{sup 14}C)dimethadione and rubidium-86, respectively. delta mu H was reduced from 124 to 3 mV in EDTA-valinomycin-treated cells at 22{degrees}C with 150 mM KCl and 0.1 mM carbonyl cyanide m-chlorophenylhydrazone. During the collapse of delta mu H, macrolide uptake increased. Erythromycin efflux studies strongly suggested that this increase was not due to an energy-dependent efflux pump but was likely due to increased outer membrane permeability. These data indicated that macrolide entry was not a delta mu H-driven active transport process but rather a passive diffusion process.

Trends in the epidemiology of invasive Haemophilus influenzae disease in Queensland, Australia from 2000 to 2013: what is the impact of an increase in invasive non-typable H. influenzae (NTHi)?

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Wan Sai Cheong, J; Smith, H; Heney, C; Robson, J; Schlebusch, S; Fu, J; Nourse, C

2015-10-01

Following the introduction of vaccination against Haemophilus influenzae type b (Hib), cases of invasive encapsulated Hib disease have decreased markedly. This study aimed to examine subsequent epidemiological trends in invasive H. influenzae disease in Queensland, Australia and in particular, assess the clinical impact and public health implications of invasive non-typable H. influenzae (NTHi) strains. A multicentre retrospective study was conducted from July 2000 to June 2013. Databases of major laboratories in Queensland including Queensland Forensic and Scientific Services (jurisdictional referral laboratory for isolate typing) were examined to identify cases. Demographic, infection site, Indigenous status, serotype, and mortality data were collected. In total, 737 invasive isolates were identified, of which 586 (79·5%) were serotyped. Hib, NTHi and encapsulated non-b strains, respectively, constituted 12·1%, 69·1% and 18·8% of isolates. The predominant encapsulated non-b strains were f (45·5%) and a (27·3%) serotypes. Of isolates causing meningitis, 48·9% were NTHi, 14·9% Hib, 14·9% Hie, 10·6% Hif, 6·4% Hia and 4·3% were untyped. During the study period, there was an increase in the incidence of invasive NTHi disease (P = 0·007) with seasonal peaks in winter and spring (P 0·001) and Hib (P = 0·039) than non-Indigenous patients. In Queensland, invasive H. influenzae disease is now predominantly encountered in adults and most commonly caused by NTHi strains with demonstrated pathogenicity extending to otherwise young or immunocompetent individuals. Routine public health notification of these strains is recommended and recent available immunization options should be considered.

Comparison of radiometric and conventional culture systems in detecting Haemophilus influenzae type b bacteremia in rats

International Nuclear Information System (INIS)

Mitchell, M.J.; Zwahlen, A.; Elliott, H.L.; Ford, N.K.; Charache, F.P.; Moxon, E.R.

1985-01-01

To compare the efficiency of detecting Haemophilus influenzae type b bacteremia by the BACTEC radiometric system and a conventional Trypticase soy broth blood culture system, the authors developed an in vivo model of bacteremia in rats. After intravenous injection of 50 to 200 CFU into adult rats, there was a linear logarithmic increase in CFU per milliliter of rat blood during the first 10 h (r = 0.98), allowing accurate prediction of the level of bacteremia with time. Culture bottles were inoculated with 0.5 ml of blood obtained by cardiac puncture and processed as clinical samples in the microbiology laboratory with RS and conventional protocols. They found the following. (i) The first detection of bacteremia by RS was similar to that by TSB if a Gram stain of the TSB was done on day 1 and was superior if that smear was omitted (P less than 0.01). (ii) The detection times in both systems were comparable at different magnitudes of bacteremia (10(1) to 10(4) CFU/ml). (iii) Supplementation of inoculated bottles with 2 ml of sterile rat blood interfered with Gram stain detection in TSB but resulted in increased 14 CO 2 production in RS. (iv) No difference in detection time was found between RS and TSB for four different clinical isolates. These studies show that, in a biologically relevant model, the detection of positive blood cultures for H. influenzae type b by RS was comparable to or better than detection by TSB when blood was processed analogously to clinical specimens

Reliability of Haemophilus influenzae biofilm measurement via static method, and determinants of in vitro biofilm production.

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Obaid, Najla A; Tristram, Stephen; Narkowicz, Christian K; Jacobson, Glenn A

2016-12-01

Information is lacking regarding the precision of microtitre plate (MTP) assays used to measure biofilm. This study investigated the precision of an MTP assay to measure biofilm production by nontypeable Haemophilus influenzae (NTHi) and the effects of frozen storage and inoculation technique on biofilm production. The density of bacterial final growth was determined by absorbance after 18-20 h incubation, and biofilm production was then measured by absorbance after crystal violet staining. Biofilm formation was categorised as high and low for each strain. For the high biofilm producing strains of NTHi, interday reproducibility of NTHi biofilm formation measured using the MTP assay was excellent and met the acceptance criteria, but higher variability was observed in low biofilm producers. Method of inoculum preparation was a determinant of biofilm formation with inoculum prepared directly from solid media showing increased biofilm production for at least one of the high producing strains. In general, storage of NTHi cultures at -80 °C for up to 48 weeks did not have any major effect on their ability to produce biofilm.

Screening municipal wastewater effluent and surface water used for drinking water production for the presence of ampicillin and vancomycin resistant enterococci

NARCIS (Netherlands)

Taucer-Kapteijn, M.; Hoogenboezem, Wim; Heiliegers, Laura; de Bolster, Danny; Medema, G.

2016-01-01

The emergence of clinical enterococcal isolates that are resistant to both ampicillin and vancomycin is a cause of great concern, as therapeutic alternatives for the treatment of infections caused by such organisms are becoming limited. Aquatic environments could play a role in the dissemination

Radiation sensitivity of Salmonella isolates relative to resistance to ampicillin, chloramphenicol or gentamicin

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Niemira, Brendan A.; Lonczynski, Kelly A.; Sommers, Christopher H.

2006-09-01

Antibiotic resistance of inoculated bacteria is a commonly used selective marker. Bacteria resistant to the antibiotic nalidixic acid have been shown to have an increased sensitivity to irradiation. The purpose of this research was to screen a collection of Salmonella isolates for antibiotic resistance and determine the association, if any, of antibiotic resistance with radiation sensitivity. Twenty-four clinical isolates of Salmonella were screened for native resistance to multiple concentrations of ampicillin (Amp), chloramphenicol (Chl), or gentamicin (Gm). Test concentrations were chosen based on established clinical minimum inhibitory concentration (MIC) levels, and isolates were classified as either sensitive or resistant based on their ability to grow at or above the MIC. Salmonella cultures were grown overnight at (37 °C) in antibiotic-amended tryptic soy broth (TSB). Native resistance to Gm was observed with each of the 24 isolates (100%). Eight isolates (33%) were shown to be resistant to Amp, while seven isolates (29%) were shown to be resistant to Chl. In separate experiments, Salmonella cultures were grown overnight (37 °C) in TSB, centrifuged, and the cell pellets were re-suspended in phosphate buffer. The samples were then gamma irradiated at doses up to 1.0 kGy. The D10 values (the ionizing radiation dose required to reduce the viable number of microorganisms by 90%) were determined for the 24 isolates and they ranged from 0.181 to 0.359 kGy. No correlation was found between the D10 value of the isolate and its sensitivity or resistance to each of the three antibiotics. Resistance to Amp or Chl is suggested as appropriate resistance marker for Salmonella test strains to be used in studies of irradiation.

Radiation sensitivity of Salmonella isolates relative to resistance to ampicillin, chloramphenicol or gentamicin

International Nuclear Information System (INIS)

Niemira, Brendan A.; Lonczynski, Kelly A.; Sommers, Christopher H.

2006-01-01

Antibiotic resistance of inoculated bacteria is a commonly used selective marker. Bacteria resistant to the antibiotic nalidixic acid have been shown to have an increased sensitivity to irradiation. The purpose of this research was to screen a collection of Salmonella isolates for antibiotic resistance and determine the association, if any, of antibiotic resistance with radiation sensitivity. Twenty-four clinical isolates of Salmonella were screened for native resistance to multiple concentrations of ampicillin (Amp), chloramphenicol (Chl), or gentamicin (Gm). Test concentrations were chosen based on established clinical minimum inhibitory concentration (MIC) levels, and isolates were classified as either sensitive or resistant based on their ability to grow at or above the MIC. Salmonella cultures were grown overnight at (37 o C) in antibiotic-amended tryptic soy broth (TSB). Native resistance to Gm was observed with each of the 24 isolates (100%). Eight isolates (33%) were shown to be resistant to Amp, while seven isolates (29%) were shown to be resistant to Chl. In separate experiments, Salmonella cultures were grown overnight (37 o C) in TSB, centrifuged, and the cell pellets were re-suspended in phosphate buffer. The samples were then gamma irradiated at doses up to 1.0 kGy. The D 10 values (the ionizing radiation dose required to reduce the viable number of microorganisms by 90%) were determined for the 24 isolates and they ranged from 0.181 to 0.359 kGy. No correlation was found between the D 10 value of the isolate and its sensitivity or resistance to each of the three antibiotics. Resistance to Amp or Chl is suggested as appropriate resistance marker for Salmonella test strains to be used in studies of irradiation

Antibacterial activity of Artemisia asiatica essential oil against some common respiratory infection causing bacterial strains and its mechanism of action in Haemophilus influenzae.

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Huang, Jiehui; Qian, Chao; Xu, Hongjie; Huang, Yanjie

2018-01-01

The main objective of the current study was to investigate the chemical composition of the essential oil of Artemisia asiatica together with investigating the antibacterial effects it exerts on several common respiratory infection causing bacteria including Haemophilus influenzae. Its mechanism of action was studied using various state-of-the-art assays like scanning electron microscopy, DNA, RNA and protein leakage assays, growth curve assays etc. The essential oil was extracted from the leaves of A. asiatica by supercritical CO 2 fluid extraction technology. Chemical composition of essential oils was analyzed by gas chromatography-mass-spectrometry (GC-MS). The antibacterial activity was evaluated against 6 bacteria by the paper disc diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC) values of the essential oil were estimated by agar dilution method. The antibacterial mechanism was evaluated by growth curve, the integrity of cell membrane and scanning electronmicroscope (SEM). Gas chromatographic analysis of the A. asiatica essential oil led to the identification of 16 chemical constituents accounting for 97.2% of the total oil composition. The major components were found to be Piperitone, (z)-davanone, p-cymene and 1, 8-cineole. The essential oil showed maximum growth inhibition against Haemophilus influenzae with a zone of inhibition of 24.5 mm and MIC/MBC values of 1.9/4.5 mg/mL respectively. Bacteria treated with the essential oil led to a rapid decrease in the number of viable cells. On adding the essential oil of A. asiatica to the bacterial culture, the constituents of the bacterial cell got released into the medium and this cell constituent release increased with increasing doses of the essential oil. SEM showed that the bacterial cells treated with the essential oil showed damaged cell wall, deformed cell morphology and shrunken cells. Copyright © 2017. Published by Elsevier Ltd.

Antimicrobial susceptibility patterns of Brazilian Haemophilus parasuis field isolates

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Michela Miani

Full Text Available ABSTRACT: Haemophilus parasuis is the etiological agent of Glässer’s disease (GD, an ubiquitous infection of swine characterized by systemic fibrinous polyserositis, polyarthritis and meningitis. Intensive use of antimicrobial agents in swine husbandries during the last years triggered the development of antibiotic resistances in bacterial pathogens. Thus, regular susceptibility testing is crucial to ensure efficacy of different antimicrobial agents to this porcine pathogen. In this study, 50 clinical isolates from South Brazilian pig herds were characterized and analyzed for their susceptibility to commonly used antibiotic. The identification and typing of clinical isolates was carried out by a modified indirect hemagglutination assay combined with a multiplex PCR. The susceptibility of each isolate was analyzed by broth microdilution method against a panel of 21 antimicrobial compounds. We found that field isolates are highly resistance to gentamycin, bacitracin, lincomycin and tiamulin, but sensitive to ampicillin, clindamycin, neomycin, penicillin, danofloxacin and enrofloxacin. Furthermore, an individual susceptibility analysis indicated that enrofloxacin is effective to treat clinical isolates with the exception of those classified as serovar 1. The results presented here firstly demonstrate the susceptibility of Brazilian clinical isolates of H. parasuis to antimicrobials widely used by swine veterinary practitioners and strengthen the need to perform susceptibility test prior to antibiotic therapy during GD outbreaks. In addition, because only six antimicrobial drugs (28.6% were found effective against field isolates, a continuous surveillance of the susceptibility profile should be of major concern to the swine industry.

Beta- lactam antibiotics stimulate biofilm formation in non-typeable haemophilus influenzae by up-regulating carbohydrate metabolism.

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Siva Wu

Full Text Available Non-typeable Haemophilus influenzae (NTHi is a common acute otitis media pathogen, with an incidence that is increased by previous antibiotic treatment. NTHi is also an emerging causative agent of other chronic infections in humans, some linked to morbidity, and all of which impose substantial treatment costs. In this study we explore the possibility that antibiotic exposure may stimulate biofilm formation by NTHi bacteria. We discovered that sub-inhibitory concentrations of beta-lactam antibiotic (i.e., amounts that partially inhibit bacterial growth stimulated the biofilm-forming ability of NTHi strains, an effect that was strain and antibiotic dependent. When exposed to sub-inhibitory concentrations of beta-lactam antibiotics NTHi strains produced tightly packed biofilms with decreased numbers of culturable bacteria but increased biomass. The ratio of protein per unit weight of biofilm decreased as a result of antibiotic exposure. Antibiotic-stimulated biofilms had altered ultrastructure, and genes involved in glycogen production and transporter function were up regulated in response to antibiotic exposure. Down-regulated genes were linked to multiple metabolic processes but not those involved in stress response. Antibiotic-stimulated biofilm bacteria were more resistant to a lethal dose (10 µg/mL of cefuroxime. Our results suggest that beta-lactam antibiotic exposure may act as a signaling molecule that promotes transformation into the biofilm phenotype. Loss of viable bacteria, increase in biofilm biomass and decreased protein production coupled with a concomitant up-regulation of genes involved with glycogen production might result in a biofilm of sessile, metabolically inactive bacteria sustained by stored glycogen. These biofilms may protect surviving bacteria from subsequent antibiotic challenges, and act as a reservoir of viable bacteria once antibiotic exposure has ended.

Microbiological assay of ampicillin in serum and aqueous humor of patients given ampicillin-sulbactam injection

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Madhavan Hajib

1998-01-01

Full Text Available The aim of this study was to determine the bacterial growth inhibitory activities of ampicillin in aqueous humor and serum of patients administered ampicillin-sulbactam combination intramuscularly prior to cataract surgery. 43 patients received a combination of both antibiotics intramuscularly at varying periods (60-140 minutes prior to surgery. Aqueous humor and venous blood were collected at the beginning of the surgery. For microbiological assay, spores of Bacillus subtilis were incorporated in the agar. The test sample and the standard solutions (calibrators of ampicillin and ampicillin-sulbactam combination were placed in 3 mm wells in the agar. The diameter zones of growth inhibitory activities of ampicillin of the calibrators and the test samples measured in mm were extrapolated to the standard curve and were recorded as ampicillin activity in (μg/ml. The results of the assay were placed in 5 groups according to the time intervals between injection and collection of serum and aqueous humor (≤70, 75, 80, 90, >90 minutes. Ampicillin activities in sera and aqueous humor of group 5 (>90 minutes were significantly higher than the others (p<0.001. The ratio of ampicillin activities of sera and aqueous humor in group 5 patients was significantly lower indicating higher concentration of ampicillin activity in aqueous humor during this period. Bacterial growth inhibitory activities of ampicillin-sulbactam combination were adequate in aqueous humor of all patients with highest activity being 90 minutes after intramuscular administration indicating the potential usefulness of this antibiotic combination as chemoprophylaxis prior to cataract surgery.

The structure of Haemophilus influenzae prephenate dehydrogenase suggests unique features of bifunctional TyrA enzymes

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Chiu, Hsiu-Ju; Abdubek, Polat; Astakhova, Tamara; Axelrod, Herbert L.; Carlton, Dennis; Clayton, Thomas; Das, Debanu; Deller, Marc C.; Duan, Lian; Feuerhelm, Julie; Grant, Joanna C.; Grzechnik, Anna; Han, Gye Won; Jaroszewski, Lukasz; Jin, Kevin K.; Klock, Heath E.; Knuth, Mark W.; Kozbial, Piotr; Krishna, S. Sri; Kumar, Abhinav; Marciano, David; McMullan, Daniel; Miller, Mitchell D.; Morse, Andrew T.; Nigoghossian, Edward; Okach, Linda; Reyes, Ron; Tien, Henry J.; Trame, Christine B.; Bedem, Henry van den; Weekes, Dana; Xu, Qingping; Hodgson, Keith O.; Wooley, John; Elsliger, Marc-André; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Wilson, Ian A.

2010-01-01

The crystal structure of the prephenate dehydrogenase component of the bifunctional H. influenzae TyrA reveals unique structural differences between bifunctional and monofunctional TyrA enzymes. Chorismate mutase/prephenate dehydrogenase from Haemophilus influenzae Rd KW20 is a bifunctional enzyme that catalyzes the rearrangement of chorismate to prephenate and the NAD(P) + -dependent oxidative decarboxylation of prephenate to 4-hydroxyphenylpyruvate in tyrosine biosynthesis. The crystal structure of the prephenate dehydrogenase component (HinfPDH) of the TyrA protein from H. influenzae Rd KW20 in complex with the inhibitor tyrosine and cofactor NAD + has been determined to 2.0 Å resolution. HinfPDH is a dimeric enzyme, with each monomer consisting of an N-terminal α/β dinucleotide-binding domain and a C-terminal α-helical dimerization domain. The structure reveals key active-site residues at the domain interface, including His200, Arg297 and Ser179 that are involved in catalysis and/or ligand binding and are highly conserved in TyrA proteins from all three kingdoms of life. Tyrosine is bound directly at the catalytic site, suggesting that it is a competitive inhibitor of HinfPDH. Comparisons with its structural homologues reveal important differences around the active site, including the absence of an α–β motif in HinfPDH that is present in other TyrA proteins, such as Synechocystis sp. arogenate dehydrogenase. Residues from this motif are involved in discrimination between NADP + and NAD + . The loop between β5 and β6 in the N-terminal domain is much shorter in HinfPDH and an extra helix is present at the C-terminus. Furthermore, HinfPDH adopts a more closed conformation compared with TyrA proteins that do not have tyrosine bound. This conformational change brings the substrate, cofactor and active-site residues into close proximity for catalysis. An ionic network consisting of Arg297 (a key residue for tyrosine binding), a water molecule, Asp206 (from

Ammonia produced by bacterial colonies promotes growth of ampicillin-sensitive Serratia sp. by means of antibiotic inactivation.

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Cepl, Jaroslav; Blahůšková, Anna; Cvrčková, Fatima; Markoš, Anton

2014-05-01

Volatiles produced by bacterial cultures are known to induce regulatory and metabolic alterations in nearby con-specific or heterospecific bacteria, resulting in phenotypic changes including acquisition of antibiotic resistance. We observed unhindered growth of ampicillin-sensitive Serratia rubidaea and S. marcescens on ampicillin-containing media, when exposed to volatiles produced by dense bacterial growth. However, this phenomenon appeared to result from pH increase in the medium caused by bacterial volatiles rather than alterations in the properties of the bacterial cultures, as alkalization of ampicillin-containing culture media to pH 8.5 by ammonia or Tris exhibited the same effects, while pretreatment of bacterial cultures under the same conditions prior to antibiotic exposure did not increase ampicillin resistance. Ampicillin was readily inactivated at pH 8.5, suggesting that observed bacterial growth results from metabolic alteration of the medium, rather than an active change in the target bacterial population (i.e. induction of resistance or tolerance). However, even such seemingly simple mechanism may provide a biologically meaningful basis for protection against antibiotics in microbial communities growing on semi-solid media. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Antimicrobial activity of berberine alone and in combination with ampicillin or oxacillin against methicillin-resistant Staphylococcus aureus.

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Yu, Hyeon-Hee; Kim, Kang-Ju; Cha, Jeong-Dan; Kim, Hae-Kyoung; Lee, Young-Eun; Choi, Na-Young; You, Yong-Ouk

2005-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) bacteria have been responsible for substantial morbidity and mortality in hospitals because they usually have multidrug resistance. Some natural products are candidates as new antibiotic substances. In the present study, we investigated the antimicrobial activity of berberine, the main antibacterial substance of Coptidis rhizoma (Coptis chinensis Franch) and Phellodendri cortex (Phellodendron amurense Ruprecht), against clinical isolates of MRSA, and the effects of berberine on the adhesion to MRSA and intracellular invasion into human gingival fibroblasts (HGFs). Berberine showed antimicrobial activity against all tested strains of MRSA. Minimum inhibition concentrations (MICs) of berberine against MRSA ranged from 32 to 128 microg/mL. Ninety percent inhibition of MRSA was obtained with 64 microg/mL or less of berberine. In the checkerboard dilution test, berberine markedly lowered the MICs of ampicillin and oxacillin against MRSA. An additive effect was found between berberine and ampicillin, and a synergistic effect was found between berberine and oxacillin against MRSA. In the presence of 1-50 microg/mL berberine, MRSA adhesion and intracellular invasion were notably decreased compared with the vehicle-treated control group. These results suggest that berberine may have antimicrobial activity and the potential to restore the effectiveness of beta-lactam antibiotics against MRSA, and inhibit the MRSA adhesion and intracellular invasion in HGFs.

Genetic makeup of amantadine-resistant and oseltamivir-resistant human influenza A/H1N1 viruses.

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Zaraket, Hassan; Saito, Reiko; Suzuki, Yasushi; Baranovich, Tatiana; Dapat, Clyde; Caperig-Dapat, Isolde; Suzuki, Hiroshi

2010-04-01

The emergence and widespread occurrence of antiviral drug-resistant seasonal human influenza A viruses, especially oseltamivir-resistant A/H1N1 virus, are major concerns. To understand the genetic background of antiviral drug-resistant A/H1N1 viruses, we performed full genome sequencing of prepandemic A/H1N1 strains. Seasonal influenza A/H1N1 viruses, including antiviral-susceptible viruses, amantadine-resistant viruses, and oseltamivir-resistant viruses, obtained from several areas in Japan during the 2007-2008 and 2008-2009 influenza seasons were analyzed. Sequencing of the full genomes of these viruses was performed, and the phylogenetic relationships among the sequences of each individual genome segment were inferred. Reference genome sequences from the Influenza Virus Resource database were included to determine the closest ancestor for each segment. Phylogenetic analysis revealed that the oseltamivir-resistant strain evolved from a reassortant oseltamivir-susceptible strain (clade 2B) which circulated in the 2007-2008 season by acquiring the H275Y resistance-conferring mutation in the NA gene. The oseltamivir-resistant lineage (corresponding to the Northern European resistant lineage) represented 100% of the H1N1 isolates from the 2008-2009 season and further acquired at least one mutation in each of the polymerase basic protein 2 (PB2), polymerase basic protein 1 (PB1), hemagglutinin (HA), and neuraminidase (NA) genes. Therefore, a reassortment event involving two distinct oseltamivir-susceptible lineages, followed by the H275Y substitution in the NA gene and other mutations elsewhere in the genome, contributed to the emergence of the oseltamivir-resistant lineage. In contrast, amantadine-resistant viruses from the 2007-2008 season distinctly clustered in clade 2C and were characterized by extensive amino acid substitutions across their genomes, suggesting that a fitness gap among its genetic components might have driven these mutations to maintain it in the

Systematic review of influenza resistance to the neuraminidase inhibitors

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Boivin Guy

2011-05-01

Full Text Available Abstract Background Antivirals play a critical role in the prevention and the management of influenza. One class of antivirals, neuraminidase inhibitors (NAIs, is effective against all human influenza viruses. Currently there are two NAI drugs which are licensed worldwide: oseltamivir (Tamiflu® and zanamivir (Relenza®; and two drugs which have received recent approval in Japan: peramivir and laninamivir. Until recently, the prevalence of antiviral resistance has been relatively low. However, almost all seasonal H1N1 strains that circulated in 2008-09 were resistant to oseltamivir whereas about 1% of tested 2009 pandemic H1N1 viruses were found to be resistant to oseltamivir. To date, no studies have demonstrated widespread resistance to zanamivir. It seems likely that the literature on antiviral resistance associated with oseltamivir as well as zanamivir is now sufficiently comprehensive to warrant a systematic review. The primary objectives were to systematically review the literature to determine the incidence of resistance to oseltamivir, zanamivir, and peramivir in different population groups as well as assess the clinical consequences of antiviral resistance. Methods We searched MEDLINE and EMBASE without language restrictions in September 2010 to identify studies reporting incidence of resistance to oseltamivir, zanamivir, and peramivir. We used forest plots and meta-analysis of incidence of antiviral resistance associated with the three NAIs. Subgroup analyses were done across a number of population groups. Meta-analysis was also performed to evaluate associations between antiviral resistance and clinical complications and symptoms. Results We identified 19 studies reporting incidence of antiviral resistance. Meta-analysis of 15 studies yielded a pooled incidence rate for oseltamivir resistance of 2.6% (95%CI 0.7% to 5.5%. The incidence rate for all zanamivir resistance studies was 0%. Only one study measured incidence of antiviral

Relative Contribution of P5 and Hap Surface Proteins to Nontypable Haemophilus influenzae Interplay with the Host Upper and Lower Airways

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Viadas, Cristina; Ruiz de los Mozos, Igor; Valle, Jaione; Bengoechea, José Antonio; Garmendia, Junkal

2015-01-01

Nontypable Haemophilus influenzae (NTHi) is a major cause of opportunistic respiratory tract disease, and initiates infection by colonizing the nasopharynx. Bacterial surface proteins play determining roles in the NTHi-airways interplay, but their specific and relative contribution to colonization and infection of the respiratory tract has not been addressed comprehensively. In this study, we focused on the ompP5 and hap genes, present in all H. influenzae genome sequenced isolates, and encoding the P5 and Hap surface proteins, respectively. We employed isogenic single and double mutants of the ompP5 and hap genes generated in the pathogenic strain NTHi375 to evaluate P5 and Hap contribution to biofilm growth under continuous flow, to NTHi adhesion, and invasion/phagocytosis on nasal, pharyngeal, bronchial, alveolar cultured epithelial cells and alveolar macrophages, and to NTHi murine pulmonary infection. We show that P5 is not required for bacterial biofilm growth, but it is involved in NTHi interplay with respiratory cells and in mouse lung infection. Mechanistically, P5NTHi375 is not a ligand for CEACAM1 or α5 integrin receptors. Hap involvement in NTHi375-host interaction was shown to be limited, despite promoting bacterial cell adhesion when expressed in H. influenzae RdKW20. We also show that Hap does not contribute to bacterial biofilm growth, and that its absence partially restores the deficiency in lung infection observed for the ΔompP5 mutant. Altogether, this work frames the relative importance of the P5 and Hap surface proteins in NTHi virulence. PMID:25894755

Vigilancia de la resistencia a los antibacterianos en Argentina. Programa WHONET, 1995-1996 Monitoring antimicrobial resistance in Argentina: the WHONET program, 1995-1996

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Alicia Rossi

1999-10-01

%, respectivamente. Se detectó resistencia a las cefalosporinas de tercera generación en 40% de los aislados de Salmonella spp. recuperados en hospitales pediátricos. En casos de meningitis bacteriana, las tasas de resistencia de Streptococcus pneumoniae a la penicilina (18% y de Haemophilus influenzae a la ampicilina (19% se situaron en el rango intermedio de las descritas en países americanos y europeos.The World Health Organization has implemented a surveillance program for antimicrobial resistance that is known as WHONET. In Argentina the program was developed through a network of 23 public and private hospitals that participate in national and international quality-control programs. Between January 1995 and December 1996, the antimicrobial susceptibility of 16 073 consecutive clinical isolates was determined, using the recommended standards of the National Committee for Clinical Laboratory Standards of the United States of America. More than half of the Escherichia coli urinary isolates were resistant to ampicillin and more than 30% to trimethoprim/sulfamethoxazole (SXT. When the percentage of resistant isolates from outpatients (OPs was compared to that observed in hospitalized patients (HPs, a marked difference in antimicrobial activity was noted in the case of gentamicin (2% from OPs resistant vs. 8% from HPs resistant, norfloxacin (2% vs. 6%, and third-generation cephalosporins (7% vs. 15%. Of the Klebsiella pneumoniae isolates recovered from blood cultures, 71% and 60% showed resistance to third-generation cephalosporins and to gentamicin, respectively. The overall rate of oxacillin resistance in Staphylococcus aureus was 39%. Around half of the Enterococcus spp. isolates showed high resistance to aminoglycosides, but resistance to glycopeptides was not found. In Argentina, ampicillin and SXT were not suitable for treating diarrhea. Shigella flexneri had a higher number of isolates resistant to both of those drugs (87% and 74%, respectively than Sh. sonnei did (47% and

Structural Analysis of Substrate, Reaction Intermediate, and Product Binding in Haemophilus influenzae Biotin Carboxylase

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Broussard, Tyler C.; Pakhomova, Svetlana; Neau, David B.; Bonnot, Ross; Waldrop, Grover L.

2015-01-01

Acetyl-CoA carboxylase catalyzes the first and regulated step in fatty acid synthesis. In most Gram-negative and Gram-positive bacteria, the enzyme is composed of three proteins: biotin carboxylase, a biotin carboxyl carrier protein (BCCP), and carboxyltransferase. The reaction mechanism involves two half-reactions with biotin carboxylase catalyzing the ATP-dependent carboxylation of biotin-BCCP in the first reaction. In the second reaction, carboxyltransferase catalyzes the transfer of the carboxyl group from biotin-BCCP to acetyl-CoA to form malonyl-CoA. In this report, high-resolution crystal structures of biotin carboxylase from Haemophilus influenzae were determined with bicarbonate, the ATP analogue AMPPCP; the carboxyphosphate intermediate analogues, phosphonoacetamide and phosphonoformate; the products ADP and phosphate; and the carboxybiotin analogue N1′-methoxycarbonyl biotin methyl ester. The structures have a common theme in that bicarbonate, phosphate, and the methyl ester of the carboxyl group of N1′-methoxycarbonyl biotin methyl ester all bound in the same pocket in the active site of biotin carboxylase and as such utilize the same set of amino acids for binding. This finding suggests a catalytic mechanism for biotin carboxylase in which the binding pocket that binds tetrahedral phosphate also accommodates and stabilizes a tetrahedral dianionic transition state resulting from direct transfer of CO2 from the carboxyphosphate intermediate to biotin. PMID:26020841

Neuraminidase inhibitor resistance in influenza: assessing the danger of its generation and spread.

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Andreas Handel

2007-12-01

Full Text Available Neuraminidase Inhibitors (NI are currently the most effective drugs against influenza. Recent cases of NI resistance are a cause for concern. To assess the danger of NI resistance, a number of studies have reported the fraction of treated patients from which resistant strains could be isolated. Unfortunately, those results strongly depend on the details of the experimental protocol. Additionally, knowing the fraction of patients harboring resistance is not too useful by itself. Instead, we want to know how likely it is that an infected patient can generate a resistant infection in a secondary host, and how likely it is that the resistant strain subsequently spreads. While estimates for these parameters can often be obtained from epidemiological data, such data is lacking for NI resistance in influenza. Here, we use an approach that does not rely on epidemiological data. Instead, we combine data from influenza infections of human volunteers with a mathematical framework that allows estimation of the parameters that govern the initial generation and subsequent spread of resistance. We show how these parameters are influenced by changes in drug efficacy, timing of treatment, fitness of the resistant strain, and details of virus and immune system dynamics. Our study provides estimates for parameters that can be directly used in mathematical and computational models to study how NI usage might lead to the emergence and spread of resistance in the population. We find that the initial generation of resistant cases is most likely lower than the fraction of resistant cases reported. However, we also show that the results depend strongly on the details of the within-host dynamics of influenza infections, and most importantly, the role the immune system plays. Better knowledge of the quantitative dynamics of the immune response during influenza infections will be crucial to further improve the results.

Impact of Haemophilus influenzae type b conjugate vaccine on bacterial meningitis in the Dominican Republic Impacto de la vacuna conjugada contra Haemophilus influenzae tipo b sobre la meningitis bacteriana en la República Dominicana

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Ellen H. Lee

2008-09-01

Full Text Available OBJECTIVES: Widespread use of Haemophilus influenzae type b (Hib vaccines has dramatically reduced the burden of Hib disease throughout the Americas. Few studies have evaluated the impact of Hib vaccination on non-culture-confirmed disease. This study analyzed trends in probable bacterial meningitis before and after the introduction of Hib vaccine in the Dominican Republic and estimated vaccine effectiveness against Hib meningitis. METHODS: Meningitis cases among children OBJETIVOS: El uso generalizado de la vacuna contra Haemophilus influenzae tipo b (Hib ha permitido reducir radicalmente la carga de enfermedad por Hib en las Américas. Pocos estudios han evaluado el impacto de la vacunación contra Hib sobre los casos no confirmados mediante cultivo. En este estudio se analizaron las tendencias en el número de casos probables de meningitis bacteriana antes y después de la introducción de la vacuna contra Hib en la República Dominicana y se estimó la eficacia de la vacuna contra la meningitis. MÉTODOS: Se identificaron los casos de meningitis en niños menores de 5 años a partir de los registros de ingreso del principal hospital pediátrico de Santo Domingo entre 1998 y 2004. Los casos de meningitis con probable etiología bacteriana se clasificaron según criterios de laboratorio; los casos confirmados contaban con cultivo bacteriano positivo o detección de antígenos específicos en el líquido cefalorraquídeo. Se calcularon las tasas de incidencia acumulada de casos confirmados y probables de meningitis en los niños que vivían en el Distrito Nacional. Los casos confirmados de meningitis por Hib se incorporaron a un estudio de casos y controles -pareados según la edad y el barrio de residencia- para calcular la eficacia de la vacuna. RESULTADOS: Antes de la introducción de la vacuna, la tasa anual de meningitis de posible etiología bacteriana era de 49 casos por 100 000 niños menores de 5 años; de los casos confirmados de

Aislamientos bacterianos de muestras respiratorias de pacientes pediátricos con fibrosis quística y su distribución por edades Bacterial isolates from respiratory samples of pediatric patients with cystic fibrosis and their distribution by ages

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Natalia P Busquets

2013-03-01

Full Text Available Se investigaron los microorganismos aislados de muestras respiratorias de 50 pacientes pediátricos con fibrosis quística. Se analizó la distribución por edades y se examinó la resistencia a los antimicrobianos, la intermitencia de los aislamientos y la presencia de coinfecciones. Se aisló Staphylococcus aureus en el 72 % de los pacientes, seguido de Pseudomonas aeruginosa (58 %, Haemophilus influenzae (56 % y complejo Burkholderia cepacia (12 %. Encontramos baja frecuencia de aislamientos de P. aeruginosa resistentes a los antibióticos p-lactámicos (13,8 %. El 50,0 % de S. aureus fue resistente a la meticilina. El 57,1 % de H. influenzae fue resistente a la ampicilina por producción de ß-lactamasa. En niños menores de 4 años predominó S. aureus, seguido de P. aeruginosa y H. influenzae. Este orden se observó en todos los grupos etarios analizados, excepto en el de los niños de 10 a 14 años. Los aislamientos de Stenotrophomonas maltophilia y Achromobacter xylosoxidans fueron intermitentes y estuvieron acompañados por otros microorganismos. En suma, en este estudio observamos una gran variedad de especies bacterianas, lo que impone la necesidad de realizar rigurosos estudios microbiológicos en los materiales respiratorios de estos pacientes.The bacterial isolates from respiratory samples of 50 pediatric patients with cystic fibrosis, their distribution by ages and antimicrobial resistance pattern as well as the intermittence of isolations and coinfections, were investigated. Staphylococcus aureus was isolated in 72 % of patients, followed by Pseudomonas aeruginosa (58 %, Haemophilus. influenzae (56 %, and the Burkholderia cepacia complex (12 %. The frequency of resistance of P. aeruginosa isolates to ß-lactam antibiotics was low (13.8 %. Fifty percent of S. aureus isolates was methicillin-resistant, and 57.1 % of H. influenza was ampicillin-resistant due to ß-lactamase production. In children under 4 years-old, S. aureus was

Development of a diagnostic kit for Tamiflu-resistant influenza A (H1N1)

International Nuclear Information System (INIS)

Jung, I. L.; Hong, S. W.

2012-01-01

Swine influenza A, which has been pandemic worldwide since 2009, is a new type virus derived from A type influenza. Although some drugs against the contageous disease, such as relenza and tamiflu, have been commercialized, those drug resistant viruses could be also followed by the wide usage of drugs. For examples, Tamiflu-resistant viruses, the mutant type viruses, can not be cured by the treatment of tamiflu anymore. Thus, a quick diagnosis for the wild type (tamiflu-sensitive) and mutant (tamiflu-resistant) virus would be essential in order to prevent the wide spread of viruses. In spite of that, unfortunately, very few studies have been conducted until now. If we could tell the differences between tamiflu-resistant and -sensitive patients using by the proper diagnostic kit, not only patient specific treatment would be possible, but also the spread of viruses would be effectively prevented. Currently used detection methods for the swine influenza A H1N1, which were originated from CDC, USA, can not detect the tamiflu-resistant swine influenza A H1N1, but only can detect tamiflu-sensitive wine influenza A H1N1. In this study, all the primers for the detection of swInfA, swH1, MP and NA (neuraminidase) have been developed in order to detect both tamiflu-resistant and tamiflu-sensitive swine influenza A H1N1s simultaneously, and then, new multiplex RT-PCR methods has been established

Development of a diagnostic kit for Tamiflu-resistant influenza A (H1N1)

Energy Technology Data Exchange (ETDEWEB)

Jung, I. L.; Hong, S. W.

2012-01-15

Swine influenza A, which has been pandemic worldwide since 2009, is a new type virus derived from A type influenza. Although some drugs against the contageous disease, such as relenza and tamiflu, have been commercialized, those drug resistant viruses could be also followed by the wide usage of drugs. For examples, Tamiflu-resistant viruses, the mutant type viruses, can not be cured by the treatment of tamiflu anymore. Thus, a quick diagnosis for the wild type (tamiflu-sensitive) and mutant (tamiflu-resistant) virus would be essential in order to prevent the wide spread of viruses. In spite of that, unfortunately, very few studies have been conducted until now. If we could tell the differences between tamiflu-resistant and -sensitive patients using by the proper diagnostic kit, not only patient specific treatment would be possible, but also the spread of viruses would be effectively prevented. Currently used detection methods for the swine influenza A H1N1, which were originated from CDC, USA, can not detect the tamiflu-resistant swine influenza A H1N1, but only can detect tamiflu-sensitive wine influenza A H1N1. In this study, all the primers for the detection of swInfA, swH1, MP and NA (neuraminidase) have been developed in order to detect both tamiflu-resistant and tamiflu-sensitive swine influenza A H1N1s simultaneously, and then, new multiplex RT-PCR methods has been established.

Modeling the growth dynamics of multiple Escherichia coli strains in the pig intestine following intramuscular ampicillin treatment.

Science.gov (United States)

Ahmad, Amais; Zachariasen, Camilla; Christiansen, Lasse Engbo; Græsbøll, Kaare; Toft, Nils; Matthews, Louise; Nielsen, Søren Saxmose; Olsen, John Elmerdahl

2016-09-06

This study evaluated how dosing regimen for intramuscularly-administered ampicillin, composition of Escherichia coli strains with regard to ampicillin susceptibility, and excretion of bacteria from the intestine affected the level of resistance among Escherichia coli strains in the intestine of nursery pigs. It also examined the dynamics of the composition of bacterial strains during and after the treatment. The growth responses of strains to ampicillin concentrations were determined using in vitro growth curves. Using these results as input data, growth predictions were generated using a mathematical model to simulate the competitive growth of E. coli strains in a pig intestine under specified plasma concentration profiles of ampicillin. In vitro growth results demonstrated that the resistant strains did not carry a fitness cost for their resistance, and that the most susceptible strains were more affected by increasing concentrations of antibiotics that the rest of the strains. The modeling revealed that short treatment duration resulted in lower levels of resistance and that dosing frequency did not substantially influence the growth of resistant strains. Resistance levels were found to be sensitive to the number of competing strains, and this effect was enhanced by longer duration of treatment. High excretion of bacteria from the intestine favored resistant strains over sensitive strains, but at the same time it resulted in a faster return to pre-treatment levels after the treatment ended. When the duration of high excretion was set to be limited to the treatment time (i.e. the treatment was assumed to result in a cure of diarrhea) resistant strains required longer time to reach the previous level. No fitness cost was found to be associated with ampicillin resistance in E. coli. Besides dosing factors, epidemiological factors (such as number of competing strains and bacterial excretion) influenced resistance development and need to be considered further in

Economic evaluations of Haemophilus influenzae type b (Hib) vaccine: a systematic review.

Science.gov (United States)

Chongmelaxme, Bunchai; Hammanee, Maythika; Phooaphirak, Wariya; Kotirum, Surachai; Hutubessy, Raymond; Chaiyakunapruk, Nathorn

2017-10-01

The World Health Organization (WHO) recommends the use of Haemophilus influenzae type b (Hib) conjugate vaccines, but China and Thailand have not used Hib vaccination in their national immunization programs. This systematic review aimed to update published economic evaluations of Hib vaccinations and to determine factors that potentially affected their cost-effectiveness. Searches were performed from the inception until December 2015 using 13 databases: CAB direct; CEA registry; EconLit; EMBASE; E-library; NHSEED; PAHO; POPLINE; PubMed; Redalyc project; RePEc; SciELO; and WHOLIS. Reference lists of relevant studies and grey literature were also searched. Full economic evaluations of Hib vaccination with results of costs and outcomes were included. The WHO checklist was used to evaluate the quality of the included studies. Data from eligible studies were extracted using a standardized data collection form. Out of 830 articles, 27 were included. Almost half of the studies (12/27) were conducted in high-income countries. Twelve studies (12/27) investigated the Hib vaccine as an addition to the existing vaccination program. Most studies (17/27) examined a 3-dose schedule of Hib vaccine. Nineteen studies (19/27) reported the model used, where all were decision tree models. Most of the studies (23/27) demonstrated an economic value of Hib vaccination programs, key influential parameters being incidence rates of Hib disease and vaccine price. Hib vaccination programs are mostly found to be cost-effective across geographic regions and country income levels, and Hib vaccination is recommended for inclusion into all national immunization programs. The findings are expected to support policy-makers for making decisions on allocating limited resources of the Hib vaccination program effectively.

Degradation of ampicillin in pig manure slurry and an aqueous ampicillin solution using electron beam irradiation

Science.gov (United States)

Chung, Byung Yeoup; Kim, Jae-Sung; Lee, Min Hee; Lee, Kang Soo; Hwang, Seon Ah; Cho, Jae Young

2009-07-01

This study was carried out to evaluate the efficiency of degradation of antibiotic ampicillin in pig manure slurry and an aqueous ampicillin solution with the use of electron beam irradiation as a function of the absorbed dose. The degradation efficiency of ampicillin was close to 95% at an absorbed dose of 10 kGy. The degradation of ampicillin followed a "first-order" reaction rate with respect to absorbed dose. The results demonstrate that the electron beam irradiation technology is an effective means to remove antibiotics in manure and bodies of water.

Degradation of ampicillin in pig manure slurry and an aqueous ampicillin solution using electron beam irradiation

International Nuclear Information System (INIS)

Chung, Byung Yeoup; Kim, Jae-Sung; Lee, Min Hee; Lee, Kang Soo; Hwang, Seon Ah; Cho, Jae Young

2009-01-01

This study was carried out to evaluate the efficiency of degradation of antibiotic ampicillin in pig manure slurry and an aqueous ampicillin solution with the use of electron beam irradiation as a function of the absorbed dose. The degradation efficiency of ampicillin was close to 95% at an absorbed dose of 10 kGy. The degradation of ampicillin followed a 'first-order' reaction rate with respect to absorbed dose. The results demonstrate that the electron beam irradiation technology is an effective means to remove antibiotics in manure and bodies of water.

Haemophilus influenzae : Caracterización de aislamientos recuperados de enfermedades invasivas en Cuba durante el período 2008-2011

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Gilda Toraño

2012-12-01

Full Text Available Con el objetivo de caracterizar los aislamientos de Haemophilus influenzae, responsables de enfermedades invasivas en Cuba, en la etapa posterior a la vacunación se estudió el total de los recuperados durante el período 2008-2011, remitidos al Instituto "Pedro Kourí" desde diferentes provincias del país. La confirmación de especie y determinación de serotipos se realizó atendiendo al requerimiento de los factores V y X y empleando el método de aglutinación en lámina, respectivamente. Se definieron los biotipos a través de las pruebas de indol, urea y ornitina; se determinó la concentración mínima inhibitoria (CMI mediante la prueba del elipsómetro para la ampicilina, la ceftriaxona, el cloranfenicol y la rifampicina. Para 23 aislamientos se corroboró la identificación como H. influenzae : 21 fueron serotipables y 2 no tipables (HNT. El 90,4% de los serotipables fueron serotipo b y se detectaron dos serotipos a. Nueve aislamientos de H. influenzae b pertenecieron al biotipo I y los aislamientos, serotipo a y HNT, al biotipo II. En una cepa se demostró producción de la enzima ß-lactamasa y resistencia para la ampicilina y el cloranfenicol, con valores de CMI= 8 y 12 µg/mL, respectivamente. Se puso en evidencia que a pesar de la disminución de la incidencia de la enfermedad invasiva por Hib, este serotipo aún constituye el más frecuente y se alerta sobre la necesidad de una vigilancia sostenida que permita detectar fallos vacunales. La susceptibilidad antimicrobiana demostrada para este período pudiera considerarse como un beneficio adicional de la introducción de la vacunación en Cuba.

Overexpression and Purification of C-terminal Fragment of the Passenger Domain of Hap Protein from Nontypeable Haemophilus influenzae in a Highly Optimized Escherichia coli Expression System

Science.gov (United States)

Tabatabaee, Akram; Siadat, Seyed Davar; Moosavi, Seyed Fazllolah; Aghasadeghi, Mohammad Reza; Memarnejadian, Arash; Pouriayevali, Mohammad Hassan; Yavari, Neda

2013-01-01

Background Nontypeable Haemophilus influenzae (NTHi) is a common cause of respiratory tract disease and initiates infection by colonization in nasopharynx. The Haemophilus influenzae (H. influenzae) Hap adhesin is an auto transporter protein that promotes initial interaction with human epithelial cells. Hap protein contains a 110 kDa internal passenger domain called “HapS” and a 45 kDa C-terminal translocator domain called “Hapβ”. Hap adhesive activity has been recently reported to be connected to its Cell Binding Domain (CBD) which resides within the 311 C-terminal residues of the internal passenger domain of the protein. Furthermore, immunization with this CBD protein has been shown to prevent bacterial nasopharynx colonization in animal models. Methods To provide enough amounts of pure HapS protein for vaccine studies, we sought to develop a highly optimized system to overexpress and purify the protein in large quantities. To this end, pET24a-cbd plasmid harboring cbd sequence from NTHi ATCC49766 was constructed and its expression was optimized by testing various expression parameters such as growth media, induction temperature, IPTG inducer concentration, induction stage and duration. SDS-PAGE and Western-blotting were used for protein analysis and confirmation and eventually the expressed protein was easily purified via immobilized metal affinity chromatography (IMAC) using Ni-NTA columns. Results The highest expression level of target protein was achieved when CBD expressing E. coli BL21 (DE3) cells were grown at 37°C in 2xTY medium with 1.0 mM IPTG at mid-log phase (OD600 nm equal to 0.6) for 5 hrs. Amino acid sequence alignment of expressed CBD protein with 3 previously published CBD amino acid sequences were more than %97 identical and antigenicity plot analysis further revealed 9 antigenic domains which appeared to be well conserved among different analyzed CBD sequences. Conclusion Due to the presence of high similarity among CBD from NTHi ATCC

Evidence that UV-inducible error-prone repair is absent in Haemophilus influenzae Rd, with a discussion of the relation to error-prone repair of alkylating-agent damage

International Nuclear Information System (INIS)

Kimball, R.F.; Boling, M.E.; Perdue, S.W.

1977-01-01

Haemophilus influenzae Rd and its derivatives are mutated either not at all or to only a very small extent by ultraviolet radiation, X-rays, methyl methanesulfonate, and nitrogen mustard, though they are readily mutated by such agents as N-methyl-N'-nitro-N-nitrosoguanidine, ethyl methanesulfonate, and nitrosocarbaryl (NC). In these respects H. influenzae Rd resembles the lexA mutants of Escherichia coli that lack the SOS or reclex UV-inducible error-prone repair system. This similarity is further brought out by the observation that chloramphenicol has little or no effect on post-replication repair after UV irradiation. In E. coli, chloramphenicol has been reported to considerably inhibit post-replication repair in the wild type but not in the lexA mutant. Earlier work has suggested that most or all the mutations induced in H. influenzae by NC result from error-prone repair. Combined treatment with NC and either X-rays or UV shows that the NC error-prone repair system does not produce mutations from the lesions induced by these radiations even while it is producing them from its own lesions. It is concluded that the NC error-prone repair system or systems and the reclex error-prone system are different

Immunogenicity and effectiveness of Haemophilus influenzae type b conjugate vaccine in HIV infected and uninfected African children.

Science.gov (United States)

Madhi, Shabir A; Kuwanda, Locadiah; Saarinen, Leena; Cutland, Clare; Mothupi, Rosalia; Käyhty, Helena; Klugman, Keith P

2005-12-01

The quantitative (anti-Hib capsular polysaccharide antibody concentrations; anti-HibPS) and qualitative (bactericidal activity and avidity) aspects in immune responses to Haemophilus influenzae type b polyribosyl ribitol phospshate-CRM(197) conjugate vaccine (HibCV; HibTiter) were evaluated in 66 HIV infected children not receiving anti-retroviral therapy and 127 HIV uninfected children. Surveillance was conducted for invasive Hib disease in a cohort of 39,865 (approximately 6.4% of whom were HIV infected) children from March 1998 to June 2004. HIV infected children had lower anti-HibPS geometric mean antibody concentrations 1 month post-immunisation than HIV uninfected children (Por=1.0 microg/ml (RR 0.54; 95% CI 0.43-0.69). A lower proportion of HIV infected children than HIV uninfected children (RR 0.78; 95% CI 0.66-0.93) had measurable anti-Hib serum bactericidal activity (SBA) and the HibPS antibody concentration required for 50% killing of Hib bacteria was greater among HIV infected than HIV uninfected children (P=0.001). The estimated risk of HibCV failure was 35.1-fold greater (95% CI 14.6-84.6) amongst HIV infected than HIV uninfected children.

Safety and Immunogenicity of Coadministering a Combined Meningococcal Serogroup C and Haemophilus influenzae Type b Conjugate Vaccine with 7-Valent Pneumococcal Conjugate Vaccine and Measles, Mumps, and Rubella Vaccine at 12 Months of Age ▿

OpenAIRE

Miller, Elizabeth; Andrews, Nick; Waight, Pauline; Findlow, Helen; Ashton, Lindsey; England, Anna; Stanford, Elaine; Matheson, Mary; Southern, Joanna; Sheasby, Elizabeth; Goldblatt, David; Borrow, Ray

2010-01-01

The coadministration of the combined meningococcal serogroup C conjugate (MCC)/Haemophilus influenzae type b (Hib) vaccine with pneumococcal conjugate vaccine (PCV7) and measles, mumps, and rubella (MMR) vaccine at 12 months of age was investigated to assess the safety and immunogenicity of this regimen compared with separate administration of the conjugate vaccines. Children were randomized to receive MCC/Hib vaccine alone followed 1 month later by PCV7 with MMR vaccine or to receive all thr...

Evidence of functional cell-mediated immune responses to nontypeable Haemophilus influenzae in otitis-prone children

Science.gov (United States)

Seppanen, Elke; Tan, Dino; Corscadden, Karli J.; Currie, Andrew J.; Richmond, Peter C.; Thornton, Ruth B.

2018-01-01

Otitis media (OM) remains a common paediatric disease, despite advances in vaccinology. Susceptibility to recurrent acute OM (rAOM) has been postulated to involve defective cell-mediated immune responses to common otopathogenic bacteria. We compared the composition of peripheral blood mononuclear cells (PBMC) from 20 children with a history of rAOM (otitis-prone) and 20 healthy non-otitis-prone controls, and assessed innate and cell-mediated immune responses to the major otopathogen nontypeable Haemophilus influenzae (NTHi). NTHi was a potent stimulator of inflammatory cytokine secretion from PBMC within 4 hours, with no difference in cytokine levels produced between PBMC from cases or controls. In the absence of antigen stimulation, otitis-prone children had more circulating Natural Killer (NK) cells (potitis-prone and non-otitis-prone children (potitis-prone children are functional and respond to NTHi. CD8+ T cells and NK cells from both cases and controls produced IFNγ in response to polyclonal stimulus (Staphylococcal enterotoxin B; SEB), with more IFNγ+ CD8+ T cells present in cases than controls (pOtitis-prone children had more circulating IFNγ-producing NK cells (potitis-prone children mounted innate and T cell-mediated responses to NTHi challenge that were comparable to healthy children. These data provide evidence that otitis-prone children do not have impaired functional cell mediated immunity. PMID:29621281

Policy resistance undermines superspreader vaccination strategies for influenza.

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Chad R Wells

Full Text Available Theoretical models of infection spread on networks predict that targeting vaccination at individuals with a very large number of contacts (superspreaders can reduce infection incidence by a significant margin. These models generally assume that superspreaders will always agree to be vaccinated. Hence, they cannot capture unintended consequences such as policy resistance, where the behavioral response induced by a new vaccine policy tends to reduce the expected benefits of the policy. Here, we couple a model of influenza transmission on an empirically-based contact network with a psychologically structured model of influenza vaccinating behavior, where individual vaccinating decisions depend on social learning and past experiences of perceived infections, vaccine complications and vaccine failures. We find that policy resistance almost completely undermines the effectiveness of superspreader strategies: the most commonly explored approaches that target a randomly chosen neighbor of an individual, or that preferentially choose neighbors with many contacts, provide at best a 2% relative improvement over their non-targeted counterpart as compared to 12% when behavioral feedbacks are ignored. Increased vaccine coverage in super spreaders is offset by decreased coverage in non-superspreaders, and superspreaders also have a higher rate of perceived vaccine failures on account of being infected more often. Including incentives for vaccination provides modest improvements in outcomes. We conclude that the design of influenza vaccine strategies involving widespread incentive use and/or targeting of superspreaders should account for policy resistance, and mitigate it whenever possible.

Modeling the growth dynamics of multiple Escherichia coli strains in the pig intestine following intramuscular ampicillin treatment

DEFF Research Database (Denmark)

Ahmad, Amais; Zachariasen, Camilla; Christiansen, Lasse Engbo

2016-01-01

using a mathematical model to simulate the competitive growth of E. coli strains in a pig intestine under specified plasma concentration profiles of ampicillin. Results : In vitro growth results demonstrated that the resistant strains did not carry a fitness cost for their resistance, and that the most...... susceptible strains were more affected by increasing concentrations of antibiotics that the rest of the strains. The modeling revealed that short treatment duration resulted in lower levels of resistance and that dosing frequency did not substantially influence the growth of resistant strains. Resistance...... with ampicillin resistance in E. coli. Besides dosing factors, epidemiological factors (such as number of competing strains and bacterial excretion) influenced resistance development and need to be considered further in relation to optimal treatment strategies. The modeling approach used in the study is generic...

Ampicillin penetration into the rabbit eye

International Nuclear Information System (INIS)

Salminen, L.

1978-01-01

Distribution of intravenously injected ampicillin of 50 mg/kg was studied in the rabbit eye using radioactive tracer method. Antibiotic concentration regarded as therapeutic in the treatment of gram-negative organisms was obtained in all vascularized ocular structures. Intermediate values were measured from the cornea and aqueous humour. In the vitreous body and lens, ampicillin was unable to approach a concentration that would be effective against the common gram-negative organisms. The low ampicillin concentration in the vitreous body and lens was unchanged by systemically administered probenecid, which in other parts of the eye caused significantly higher ampicillin levels. (author)

Relation between enzyme-linked immunosorbent assay and radioimmunoassay for detection of antibodies to the capsular polysaccharide of Haemophilus influenzae type b

International Nuclear Information System (INIS)

Kristensen, K.; Weis Bentzon, M.

1992-01-01

The measurement of antibodies to the capsular polysaccharide (PRP) of Haemophilus influenzae type b (Hib) is important because vaccines inducing such antibodies are now available. We developed and evaluated an enzyme-linked immunosorbent assay (ELISA) for detection of these antibodies based on direct coating of the plates with tyraminated PRP. The assay fulfilled the requirements for parallel line assays; it was sensitive, specific, and reproducible with a coefficient of variation between days of 19%. Results from the ELISA were compared with results from radioimmunoassay and a correlation coefficient of 0.93 was found. Results obtained by the two methods were proportional and the relation was indepenedent of the antibody level. The relation between them was also unaffected by the contribution of different antibody isotypes, indicating that these were measured to the same extent by both methods. ELISA employing direct coating of the plates with tyraminated PRP represents a useful alternative for detection of antibodies when studying immunogenicity of Hib vaccines. (au)

Identification and Characterization of msf, a Novel Virulence Factor in Haemophilus influenzae.

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Jennifer M Kress-Bennett

Full Text Available Haemophilus influenzae is an opportunistic pathogen. The emergence of virulent, non-typeable strains (NTHi emphasizes the importance of developing new interventional targets. We screened the NTHi supragenome for genes encoding surface-exposed proteins suggestive of immune evasion, identifying a large family containing Sel1-like repeats (SLRs. Clustering identified ten SLR-containing gene subfamilies, each with various numbers of SLRs per gene. Individual strains also had varying numbers of SLR-containing genes from one or more of the subfamilies. Statistical genetic analyses of gene possession among 210 NTHi strains typed as either disease or carriage found a significant association between possession of the SlrVA subfamily (which we have termed, macrophage survival factor, msf and the disease isolates. The PittII strain contains four chromosomally contiguous msf genes. Deleting all four of these genes (msfA1-4 (KO resulted in a highly significant decrease in phagocytosis and survival in macrophages; which was fully complemented by a single copy of the msfA1 gene. Using the chinchilla model of otitis media and invasive disease, the KO strain displayed a significant decrease in fitness compared to the WT in co-infections; and in single infections, the KO lost its ability to invade the brain. The singly complemented strain showed only a partial ability to compete with the WT suggesting gene dosage is important in vivo. The transcriptional profiles of the KO and WT in planktonic growth were compared using the NTHi supragenome array, which revealed highly significant changes in the expression of operons involved in virulence and anaerobiosis. These findings demonstrate that the msfA1-4 genes are virulence factors for phagocytosis, persistence, and trafficking to non-mucosal sites.

A clinical trial examining the effect of increased total CRM(197) carrier protein dose on the antibody response to Haemophilus influenzae type b CRM(197) conjugate vaccine.

Science.gov (United States)

Usonis, Vytautas; Bakasenas, Vytautas; Lockhart, Stephen; Baker, Sherryl; Gruber, William; Laudat, France

2008-08-18

CRM(197) is a carrier protein in certain conjugate vaccines. When multiple conjugate vaccines with the same carrier protein are administered simultaneously, reduced response to vaccines and/or antigens related to the carrier protein may occur. This study examined responses of infants who, in addition to diphtheria toxoid/tetanus toxoid/acellular pertussis vaccine (DTaP) received either diphtheria CRM(197)-based Haemophilus influenzae type b conjugate vaccine (HbOC) or HbOC and a diphtheria CRM(197)-based combination 9-valent pneumococcal conjugate vaccine/meningococcal group C conjugate vaccine. Administration of conjugate vaccines with CRM(197) carrier protein load >50 microg did not reduce response to CRM(197) conjugate vaccines or immunogenicity to immunologically cross-reactive diphtheria toxoid.

The dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase from Haemophilus influenzae is a dinuclear metallohydrolase.

Science.gov (United States)

Cosper, Nathaniel J; Bienvenue, David L; Shokes, Jacob E; Gilner, Danuta M; Tsukamoto, Takashi; Scott, Robert A; Holz, Richard C

2003-12-03

The Zn K-edge extended X-ray absorption fine structure (EXAFS) spectra, of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE) from Haemophilus influenzae have been recorded in the presence of one or two equivalents of Zn(II) (i.e. [Zn_(DapE)] and [ZnZn(DapE)]). The Fourier transforms of the Zn EXAFS are dominated by a peak at ca. 2.0 A, which can be fit for both [Zn_(DapE)] and [ZnZn(DapE)], assuming ca. 5 (N,O) scatterers at 1.96 and 1.98 A, respectively. A second-shell feature at ca. 3.34 A appears in the [ZnZn(DapE)] EXAFS spectrum but is significantly diminished in [Zn_(DapE)]. These data show that DapE contains a dinuclear Zn(II) active site. Since no X-ray crystallographic data are available for any DapE enzyme, these data provide the first glimpse at the active site of DapE enzymes. In addition, the EXAFS data for DapE incubated with two competitive inhibitors, 2-carboxyethylphosphonic acid and 5-mercaptopentanoic acid, are also presented.

Iodometric determination of ampicillin in proprietary capsules | Ejele ...

African Journals Online (AJOL)

The concentration of ampicillin in ampicillin capsule preparations purchased in Owerri main market, Imo State of Nigeria, was determined using the iodometric titration method. The results showed that the ampicillin concentrations in the capsules contained between 250 and 260 mg/cap of ampicillin trihydrate. Statistical ...

Impacto de la vacunación contra Haemophilus influenzae tipo b en Cuba

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Dickinson Félix O.

2001-01-01

Full Text Available Objetivo. Determinar el impacto de la vacunación de menores de 2 años en Cuba contra Haemophilus influenzae tipo b (Hib, principal agente causal de la meningitis bacteriana en ese país. Métodos. La disponibilidad de vacunas conjugadas eficaces contra Hib motivó la vacunación nacional en 1999 de niños menores de 2 años, que alcanzó una cobertura de 97%. El impacto se evaluó mediante el Sistema Nacional de Vigilancia de Meningoencefalitis Bacterianas (SNVMEB. Resultados. La eficacia global de la vacunación se estimó en 99% y la incidencia general de la meningoencefalitis por Hib disminuyó de 1,3 a 0,6 por 100 000 habitantes (46,1%, observándose la mayor reducción en niños menores de 5 años (56,1%. En los menores de 1 año se redujo 70,5% y en el resto de los grupos de menores de 5 años disminuyó entre 25,9 y 49,6%. En el grupo diana para la vacunación, la incidencia se redujo 61,1%; entre los niños de este grupo que contrajeron la meningoencefalitis por Hib, solamente 8 (24,2% estaban vacunados, 7 de ellos con una sola dosis, aplicada 1 mes antes de enfermar. Conclusiones. Se ha demostrado que la vacunación a gran escala de los niños menores de 2 años contra Hib en Cuba a través del SNVMEB ha logrado disminuir notablemente la incidencia de meningoencefalitis por Hib.

Oseltamivir (Tamiflu® in the environment, resistance development in influenza A viruses of dabbling ducks and the risk of transmission of an oseltamivir-resistant virus to humans – a review

Directory of Open Access Journals (Sweden)

Josef D. Järhult

2012-06-01

Full Text Available The antiviral drug oseltamivir (Tamiflu® is a cornerstone in influenza pandemic preparedness plans worldwide. However, resistance to the drug is a growing concern. The active metabolite oseltamivir carboxylate (OC is not degraded in surface water or sewage treatment plants and has been detected in river water during seasonal influenza outbreaks. The natural influenza reservoir, dabbling ducks, can thus be exposed to OC in aquatic environments. Environmental-like levels of OC induce resistance development in influenza A/H1N1 virus in mallards. There is a risk of resistance accumulation in influenza viruses circulating among wild birds when oseltamivir is used extensively. By reassortment or direct transmission, oseltamivir resistance can be transmitted to humans potentially causing a resistant pandemic or human-adapted highly-pathogenic avian influenza virus. There is a need for more research on resistance development in the natural influenza reservoir and for a prudent use of antivirals.

Unique Determinants of Neuraminidase Inhibitor Resistance among N3, N7, and N9 Avian Influenza Viruses.

Science.gov (United States)

Song, Min-Suk; Marathe, Bindumadhav M; Kumar, Gyanendra; Wong, Sook-San; Rubrum, Adam; Zanin, Mark; Choi, Young-Ki; Webster, Robert G; Govorkova, Elena A; Webby, Richard J

2015-11-01

Human infections with avian influenza viruses are a serious public health concern. The neuraminidase (NA) inhibitors (NAIs) are the frontline anti-influenza drugs and are the major option for treatment of newly emerging influenza. Therefore, it is essential to identify the molecular markers of NAI resistance among specific NA subtypes of avian influenza viruses to help guide clinical management. NAI-resistant substitutions in NA subtypes other than N1 and N2 have been poorly studied. Here, we identified NA amino acid substitutions associated with NAI resistance among influenza viruses of N3, N7, and N9 subtypes which have been associated with zoonotic transmission. We applied random mutagenesis and generated recombinant influenza viruses carrying single or double NA substitution(s) with seven internal genes from A/Puerto Rico/8/1934 (H1N1) virus. In a fluorescence-based NA inhibition assay, we identified three categories of NA substitutions associated with reduced inhibition by NAIs (oseltamivir, zanamivir, and peramivir): (i) novel subtype-specific substitutions in or near the enzyme catalytic site (R152W, A246T, and D293N, N2 numbering), (ii) subtype-independent substitutions (E119G/V and/or D and R292K), and (iii) substitutions previously reported in other subtypes (Q136K, I222M, and E276D). Our data show that although some markers of resistance are present across NA subtypes, other subtype-specific markers can only be determined empirically. The number of humans infected with avian influenza viruses is increasing, raising concerns of the emergence of avian influenza viruses resistant to neuraminidase (NA) inhibitors (NAIs). Since most studies have focused on NAI-resistance in human influenza viruses, we investigated the molecular changes in NA that could confer NAI resistance in avian viruses grown in immortalized monolayer cells, especially those of the N3, N7, and N9 subtypes, which have caused human infections. We identified not only numerous NAI-resistant

Economic evaluation of delivering Haemophilus influenzae type b vaccine in routine immunization services in Kenya.

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Akumu, Angela Oloo; English, Mike; Scott, J Anthony G; Griffiths, Ulla K

2007-07-01

Haemophilus influenzae type b (Hib) vaccine was introduced into routine immunization services in Kenya in 2001. We aimed to estimate the cost-effectiveness of Hib vaccine delivery. A model was developed to follow the Kenyan 2004 birth cohort until death, with and without Hib vaccine. Incidence of invasive Hib disease was estimated at Kilifi District Hospital and in the surrounding demographic surveillance system in coastal Kenya. National Hib disease incidence was estimated by adjusting incidence observed by passive hospital surveillance using assumptions about access to care. Case fatality rates were also assumed dependent on access to care. A price of US$ 3.65 per dose of pentavalent diphtheria-tetanus-pertussis-hep B-Hib vaccine was used. Multivariate Monte Carlo simulations were performed in order to assess the impact on the cost-effectiveness ratios of uncertainty in parameter values. The introduction of Hib vaccine reduced the estimated incidence of Hib meningitis per 100,000 children aged disability adjusted life year (DALY) and per discounted death averted were US$ 38 (95% confidence interval, CI: 26-63) and US$ 1197 (95% CI: 814-2021) respectively. Most of the uncertainty in the results was due to uncertain access to care parameters. The break-even pentavalent vaccine price--where incremental Hib vaccination costs equal treatment costs averted from Hib disease--was US$ 1.82 per dose. Hib vaccine is a highly cost-effective intervention in Kenya. It would be cost-saving if the vaccine price was below half of its present level.

Cost-benefit analysis of a Haemophilus influenzae type b meningitis prevention programme in The Philippines.

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Limcangco, M R; Armour, C L; Salole, E G; Taylor, S J

2001-01-01

Haemophilus influenzae type b (Hib) meningitis is associated with high mortality and serious sequelae in children under 5 years of age. Vaccines which can prevent this infection are available. To evaluate the costs and benefits of a 3-dose immunisation schedule in Manila, Philippines. Government and societal perspectives. A cost-benefit analysis based on a birth cohort of 100,000 children. The state of health of the cohort with and without a Hib immunisation programme was modelled over a 5-year period. A survey of medical records of patients with Hib in Manila provided data on the extent and cost of sequelae following infection. A 3-dose Hib vaccination programme given at ages 2, 3 and 4 months. The model predicted that vaccinating children against Hib meningitis would prevent 553 cases per year in a birth cohort of 100,000, at a cost of 56,200 Philippine pesos (PHP) [$US1,605; 1998 exchange rate] per case (base case assumptions of 90% vaccine efficacy rate, 95 per 100,000 Hib incidence rate, 85% vaccination coverage). Results from the cost-benefit analyses indicated that the saving to the government would be around PHP39 million ($US1.11 million), and the saving to society would be PHP255 million ($US7.28 million). There would be a positive economic benefit for the Philippine government and for the Filipino society if a Hib vaccination programme was introduced in Manila.

Haemophilus influenzae type b disease in Auckland children during the Hib vaccination era: 1995-2009.

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Leung, Bonnie; Taylor, Susan; Drinkovic, Dragana; Roberts, Sally; Carter, Phil; Best, Emma

2012-11-09

To characterise Haemophilus influenzae type b (Hib) invasive disease in the era of Hib vaccination, in children of the greater Auckland region of New Zealand. Identification of sterile site culture positive Hib via the Auckland hospital laboratories databases and national laboratory surveillance database in the time period; 1995 to 2009. There were a total of 26 cases in the Auckland Region. Over the 15-year period, the annual incidence of invasive Hib disease was 0.61 per 100,000 (95% CI: 0.4-0.9) for children aged under 15 years and 1.65 per 100,000 (95% CI: 1.1-2.5) for children aged under 5 years. Ninety-two percent were under 5 years and 54% were under 1 year. Sixty percent of the children were of Maori and Pacific ethnicity. The predominant diagnosis was meningitis, accounting for 15 cases (60%). There were no fatalities. Forty-eight percent of affected children were completely unimmunised with the Hib vaccine which has been fully funded on the National Immunisation Schedule since 1994. Since the introduction of the Hib vaccine, the disease rates have greatly reduced in the Auckland region. Although ethnic disparities have improved amongst the cases that occur, immunisation rates in cases are low and infants remain most at risk. Current emphasis on intensifying immunisation programmes to achieve higher vaccination rates and timeliness of delivery will help in efforts to achieve elimination of the disease in New Zealand.

VACCINE IMMUNIZATION FOR PREVENTION OF PNEUMOCOCCAL, HAEMOPHILUS INFLUENZAE AND FLU AMONG SICKLY CHILDREN, WHO OFTEN SUFFER FROM PERSISTENT HETEROSPECIFIC INFECTIOUS PATHOLOGY OF THE BRONCHOPULMONARY SYSTEM

Directory of Open Access Journals (Sweden)

L.I. Ilienko

2006-01-01

Full Text Available Among serious diseases of the lower respiratory tract a special place is taken by pneumonias and chronic infectious respiratory diseases caused by pneumococcus and Haemophilus influenzae type b (HIB. The research purpose is to determine the effectiveness of vaccine combined application to treat sickly children, who often suffer from persistent infectious pathology of the respiratory tract, for flu, pneumococcal and HIB disease. 110 children aged between 3 and 12 have been vaccinated. The first part of research implied children vaccination by means of Actahib and Pneumo 23 vaccines (Sanofi Pasteur, France, the second one consisted in immunization of children with the same pathology by means of Pneumo 23, Actahib and Vaxigrip vaccines (Sanofi Pasteur, France. The researches established that within a year after HIB and Pneumo 23 vaccination the frequency of upper and lower respiratory tract acerbations reduced by 2,3 times on average; likewise, the number of system antimicrobial dosage reduced by 7,4 times along with the total duration of dosage; the carrier state of S. pneumoniae reduced by 3,7 times, H. influenzae — by 3,9 times. In the course of application of three vaccines, the frequency of persistent heat erospecific infectious bronchopulmonary pathology acerbations reduced by 3,3 times. The carrier state of S. pneumoniae reduced by 2,5 times, H. influenzae — by 4,1 times. Thus, vaccine immunization to treat for flu, pneumococcal and HIB disease in various combinations may be recoma mended for wider application to reduce the frequency and severity of heat erospecific infectious respiratory diseases among sickly children, who often suffer from various illnesses.Key words: children with recurrent diseases, vaccination, prevention, flu, H. Influenzae, S. pneumoniae.

A simplification of the enzyme-linked immunospot technique. Increased sensitivity for cells secreting IgG antibodies to Haemophilus influenzae type b capsular polysaccharide

DEFF Research Database (Denmark)

Barington, T; Sparholt, S; Juul, L

1992-01-01

A simplified enzyme-linked immunospot (ELISPOT) technique is described for the detection of cells secreting antibodies to tetanus toxoid (TT), diphtheria toxoid (DT) or Haemophilus influenzae type b capsular polysaccharide (PRP). By combining the cell suspension with the enzyme-linked secondary...... antibodies in one incubation, the second incubation and washing procedure could be omitted from the original technique. The simplified assay had the same sensitivity for anti-TT and anti-DT spot-forming cells as the ordinary ELISPOT assay. The IgG anti-PRP spots were, however, improved both in quality...... and in quantity (median: 40% more spots), while the detection of IgM and IgA anti-PRP spot-forming cells was the same in the two techniques. This simplified technique can probably also be used to save time in other antigen systems and should be considered when designing ELISPOT assays for the detection...

The dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase from Haemophilus influenzae contains two active-site histidine residues.

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Gillner, Danuta M; Bienvenue, David L; Nocek, Boguslaw P; Joachimiak, Andrzej; Zachary, Vincentos; Bennett, Brian; Holz, Richard C

2009-01-01

The catalytic and structural properties of the H67A and H349A dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase (DapE) from Haemophilus influenzae were investigated. On the basis of sequence alignment with the carboxypeptidase from Pseudomonas sp. strain RS-16, both H67 and H349 were predicted to be Zn(II) ligands. The H67A DapE enzyme exhibited a decreased catalytic efficiency (180-fold) compared with wild-type (WT) DapE towards N-succinyldiaminopimelic acid. No catalytic activity was observed for H349A under the experimental conditions used. The electronic paramagnetic resonance (EPR) and electronic absorption data indicate that the Co(II) ion bound to H349A-DapE is analogous to that of WT DapE after the addition of a single Co(II) ion. The addition of 1 equiv of Co(II) to H67A DapE provides spectra that are very different from those of the first Co(II) binding site of the WT enzyme, but that are similar to those of the second binding site. The EPR and electronic absorption data, in conjunction with the kinetic data, are consistent with the assignment of H67 and H349 as active-site metal ligands for the DapE from H. influenzae. Furthermore, the data suggest that H67 is a ligand in the first metal binding site, while H349 resides in the second metal binding site. A three-dimensional homology structure of the DapE from H. influenzae was generated using the X-ray crystal structure of the DapE from Neisseria meningitidis as a template and superimposed on the structure of the aminopeptidase from Aeromonas proteolytica (AAP). This homology structure confirms the assignment of H67 and H349 as active-site ligands. The superimposition of the homology model of DapE with the dizinc(II) structure of AAP indicates that within 4.0 A of the Zn(II) binding sites of AAP all of the amino acid residues of DapE are nearly identical.

Published sequences do not support transfer of oseltamivir resistance mutations from avian to human influenza A virus strains.

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Norberg, Peter; Lindh, Magnus; Olofsson, Sigvard

2015-03-28

Tamiflu (oseltamivir phosphate ester, OE) is a widely used antiviral active against influenza A virus. Its active metabolite, oseltamivir carboxylate (OC), is chemically stable and secreted into wastewater treatment plants. OC contamination of natural habitats of waterfowl might induce OC resistance in influenza viruses persistently infecting waterfowl, and lead to transfer of OC-resistance from avian to human influenza. The aim of this study was to evaluate whether such has occurred. A genomics approach including phylogenetic analysis and probability calculations for homologous recombination was applied on altogether 19,755 neuraminidase (N1 and N2) genes from virus sampled in humans and birds, with and without resistance mutations. No evidence for transfer of OE resistance mutations from avian to human N genes was obtained, and events suggesting recombination between human and avian influenza virus variants could not be traced in the sequence material studied. The results indicate that resistance in influenza viruses infecting humans is due to the selection pressure posed by the global OE administration in humans rather than transfer from avian influenza A virus strains carrying mutations induced by environmental exposure to OC.

Susceptibility of Haemophilus equigenitalis, the causal agent of contagious equine metritis, to 31 antimicrobial agents.

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Sugimoto, C; Isayama, Y; Kashiwazaki, M; Mitani, K

1981-01-01

The minimal inhibitory concentrations of 31 antimicrobial agents were determined for 99 isolates of Haemophilus equigenitalis by the agar dilution method. All the isolates showed good susceptibility to 26 antimicrobial agents tests, minimal inhibitory concentrations of which were less than 3.13 micrograms/ml for more than 90% of the isolates. Of these agents, 4 macrolides (erythromycin, oleandomycin, kitasamycin, tylosin), 3 tetracyclines (tetracycline, chlortetracycline, oxytetracycline), 1 peptide (colistin), 1 penicillin (ampicillin) and 1 pleuromutilin (tiamulin) were the most active agents, showing a minimal inhibitory concentration of less than 0.39 micrograms/ml for more than 90% of the isolates. The growth of more than 90% of the isolates was not inhibited by 800 micrograms/ml of streptomycin.

Assessing the oseltamivir-induced resistance risk and implications for influenza infection control strategies

Directory of Open Access Journals (Sweden)

Hsieh NH

2017-07-01

Full Text Available Nan-Hung Hsieh,1 Yi-Jun Lin,2 Ying-Fei Yang,2 Chung-Min Liao2 1Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA; 2Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan Background: Oseltamivir-resistant mutants with higher drug resistance rates and low transmission fitness costs have not accounted for influenza (subtype viruses. Predicting the impacts of neuraminidase inhibitor therapy on infection rates and transmission of drug-resistant viral strains requires further investigation.Objectives: The purpose of this study was to assess the potential risk of oseltamivir-induced resistance for influenza A (H1N1 and A (H3N2 viruses.Materials and methods: An immune-response-based virus dynamic model was used to best fit the oseltamivir-resistant A (H1N1 and A (H3N2 infection data. A probabilistic risk assessment model was developed by incorporating branching process-derived probability distribution of resistance to estimate oseltamivir-induced resistance risk.Results: Mutation rate and sensitive strain number were key determinants in assessing resistance risk. By increasing immune response, antiviral efficacy, and fitness cost, the spread of resistant strains for A (H1N1 and A (H3N2 were greatly decreased. Probability of resistance depends most strongly on the sensitive strain number described by a Poisson model. Risk of oseltamivir-induced resistance increased with increasing the mutation rate for A (H1N1 only. The ≥50% of resistance risk induced by A (H1N1 and A (H3N2 sensitive infected cells were 0.4 (95% CI: 0.28–0.43 and 0.95 (95% CI 0.93–0.99 at a mutation rate of 10−6, respectively. Antiviral drugs must be administrated within 1–1.5 days for A (H1N1 and 2–2.5 days for A (H3N2 virus infections to limit viral production.Conclusion: Probabilistic risk assessment of antiviral drug

Impact of protein D-containing pneumococcal conjugate vaccines on non-typeable Haemophilus influenzae acute otitis media and carriage.

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Clarke, Christopher; Bakaletz, Lauren O; Ruiz-Guiñazú, Javier; Borys, Dorota; Mrkvan, Tomas

2017-07-01

Protein D-containing vaccines may decrease acute otitis media (AOM) burden and nasopharyngeal carriage of non-typeable Haemophilus influenzae (NTHi). Protein D-containing pneumococcal conjugate vaccine PHiD-CV (Synflorix, GSK Vaccines) elicits robust immune responses against protein D. However, the phase III Clinical Otitis Media and PneumoniA Study (COMPAS), assessing PHiD-CV efficacy against various pneumococcal diseases, was not powered to demonstrate efficacy against NTHi; only trends of protective efficacy against NTHi AOM in children were shown. Areas covered: This review aims to consider all evidence available to date from pre-clinical and clinical phase III studies together with further evidence emerging from post-marketing studies since PHiD-CV has been introduced into routine clinical practice worldwide, to better describe the clinical utility of protein D in preventing AOM due to NTHi and its impact on NTHi nasopharyngeal carriage. Expert commentary: Protein D is an effective carrier protein in conjugate vaccines and evidence gathered from pre-clinical, clinical and observational studies suggest that it also elicits immune response that can help to reduce the burden of AOM due to NTHi. There remains a need to develop improved vaccines for prevention of NTHi disease, which could be achieved by combining protein D with other antigens.

Accelerating policy decisions to adopt haemophilus influenzae type B vaccine: a global, multivariable analysis.

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Shearer, Jessica C; Stack, Meghan L; Richmond, Marcie R; Bear, Allyson P; Hajjeh, Rana A; Bishai, David M

2010-03-16

Adoption of new and underutilized vaccines by national immunization programs is an essential step towards reducing child mortality. Policy decisions to adopt new vaccines in high mortality countries often lag behind decisions in high-income countries. Using the case of Haemophilus influenzae type b (Hib) vaccine, this paper endeavors to explain these delays through the analysis of country-level economic, epidemiological, programmatic and policy-related factors, as well as the role of the Global Alliance for Vaccines and Immunisation (GAVI Alliance). Data for 147 countries from 1990 to 2007 were analyzed in accelerated failure time models to identify factors that are associated with the time to decision to adopt Hib vaccine. In multivariable models that control for Gross National Income, region, and burden of Hib disease, the receipt of GAVI support speeded the time to decision by a factor of 0.37 (95% CI 0.18-0.76), or 63%. The presence of two or more neighboring country adopters accelerated decisions to adopt by a factor of 0.50 (95% CI 0.33-0.75). For each 1% increase in vaccine price, decisions to adopt are delayed by a factor of 1.02 (95% CI 1.00-1.04). Global recommendations and local studies were not associated with time to decision. This study substantiates previous findings related to vaccine price and presents new evidence to suggest that GAVI eligibility is associated with accelerated decisions to adopt Hib vaccine. The influence of neighboring country decisions was also highly significant, suggesting that approaches to support the adoption of new vaccines should consider supply- and demand-side factors.

Applying Central Composite Design and Response Surface Methodology to Optimize Growth and Biomass Production of Haemophilus influenzae Type b.

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Momen, Seyed Bahman; Siadat, Seyed Davar; Akbari, Neda; Ranjbar, Bijan; Khajeh, Khosro

2016-06-01

Haemophilus influenzae type b (Hib) is the leading cause of bacterial meningitis, otitis media, pneumonia, cellulitis, bacteremia, and septic arthritis in infants and young children. The Hib capsule contains the major virulence factor, and is composed of polyribosyl ribitol phosphate (PRP) that can induce immune system response. Vaccines consisting of Hib capsular polysaccharide (PRP) conjugated to a carrier protein are effective in the prevention of the infections. However, due to costly processes in PRP production, these vaccines are too expensive. To enhance biomass, in this research we focused on optimizing Hib growth with respect to physical factors such as pH, temperature, and agitation by using a response surface methodology (RSM). We employed a central composite design (CCD) and a response surface methodology to determine the optimum cultivation conditions for growth and biomass production of H. influenzae type b. The treatment factors investigated were initial pH, agitation, and temperature, using shaking flasks. After Hib cultivation and determination of dry biomass, analysis of experimental data was performed by the RSM-CCD. The model showed that temperature and pH had an interactive effect on Hib biomass production. The dry biomass produced in shaking flasks was about 5470 mg/L, which was under an initial pH of 8.5, at 250 rpm and 35° C. We found CCD and RSM very effective in optimizing Hib culture conditions, and Hib biomass production was greatly influenced by pH and incubation temperature. Therefore, optimization of the growth factors to maximize Hib production can lead to 1) an increase in bacterial biomass and PRP productions, 2) lower vaccine prices, 3) vaccination of more susceptible populations, and 4) lower risk of Hib infections.

Outcome of meningitis caused by Streptococcus pneumoniae and Haemophilus influenzae type b in children in The Gambia.

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Goetghebuer, T; West, T E; Wermenbol, V; Cadbury, A L; Milligan, P; Lloyd-Evans, N; Adegbola, R A; Mulholland, E K; Greenwood, B M; Weber, M W

2000-03-01

In developing countries, endemic childhood meningitis is a severe disease caused most commonly by Streptococcus pneumoniae or Haemophilus influenzae type b (Hib). Although many studies have shown that fatality rates associated with meningitis caused by these organisms are high in developing countries, little is known about the long-term outcome of survivors. The purpose of this study was to assess the importance of disabilities following pneumococcal and Hib meningitis in The Gambia. 257 children aged 0-12 years hospitalized between 1990 and 1995 with culture-proven S. pneumoniae (n = 134) or Hib (n = 123) meningitis were included retrospectively in the study. 48% of children with pneumococcal meningitis and 27% of children with Hib meningitis died whilst in hospital. Of the 160 survivors, 89 (55%) were followed up between September 1996 and October 1997. Of the children with pneumococcal meningitis that were traced, 58% had clinical sequelae; half of them had major disabilities preventing normal adaptation to social life. 38% of survivors of Hib meningitis had clinical sequelae, a quarter of whom had major disabilities. Major handicaps found were hearing loss, mental retardation, motor abnormalities and seizures. These data show that despite treatment with effective antibiotics, pneumococcal and Hib meningitis kill many Gambian children and leave many survivors with severe sequelae. Hib vaccination is now given routinely in The Gambia; an effective pneumococcal vaccine is needed.

Haemophilus influenzae genome evolution during persistence in the human airways in chronic obstructive pulmonary disease.

Science.gov (United States)

Pettigrew, Melinda M; Ahearn, Christian P; Gent, Janneane F; Kong, Yong; Gallo, Mary C; Munro, James B; D'Mello, Adonis; Sethi, Sanjay; Tettelin, Hervé; Murphy, Timothy F

2018-04-03

Nontypeable Haemophilus influenzae (NTHi) exclusively colonize and infect humans and are critical to the pathogenesis of chronic obstructive pulmonary disease (COPD). In vitro and animal models do not accurately capture the complex environments encountered by NTHi during human infection. We conducted whole-genome sequencing of 269 longitudinally collected cleared and persistent NTHi from a 15-y prospective study of adults with COPD. Genome sequences were used to elucidate the phylogeny of NTHi isolates, identify genomic changes that occur with persistence in the human airways, and evaluate the effect of selective pressure on 12 candidate vaccine antigens. Strains persisted in individuals with COPD for as long as 1,422 d. Slipped-strand mispairing, mediated by changes in simple sequence repeats in multiple genes during persistence, regulates expression of critical virulence functions, including adherence, nutrient uptake, and modification of surface molecules, and is a major mechanism for survival in the hostile environment of the human airways. A subset of strains underwent a large 400-kb inversion during persistence. NTHi does not undergo significant gene gain or loss during persistence, in contrast to other persistent respiratory tract pathogens. Amino acid sequence changes occurred in 8 of 12 candidate vaccine antigens during persistence, an observation with important implications for vaccine development. These results indicate that NTHi alters its genome during persistence by regulation of critical virulence functions primarily by slipped-strand mispairing, advancing our understanding of how a bacterial pathogen that plays a critical role in COPD adapts to survival in the human respiratory tract.

[Antibacterial activity of panipenem against clinical isolates in 2000 and 2001].

Science.gov (United States)

Abe, Tomomi; Fukuoka, Takashi; Sato, Yuki; Ito, Kazuyoshi; Sei, Masami

2002-12-01

As the post-marketing surveillance of panipenem/betamipron (Carbenin), MICs of panipenem (PAPM) against 1355 clinical isolates of 28 species from 15 medical institutions all over Japan from June 2000 to March 2001 were measured using the broth microdilution method approved by the Japanese Society of Chemotherapy and compared with those of parenteral carbapenem antibacterials, imipenem (IPM) and meropenem (MEPM), and parenteral cephem antibacterials, cefozopran, cefepime, and sulbactam/cefoperazone. The activity of PAPM was comparable to that of IPM against almost all species tested. Compared with MEPM, PAPM was more active against Gram-positive bacteria and Bacteroides spp., and less active against Gram-negative bacteria. Compared with the parenteral cephems, PAPM was more active against most of species tested and its MIC ranges were narrower than those of the cephems as were those of other carbapenems. In this surveillance study, the incidence of resistance in various species were as follows: 39.3% for methicillin-resistant Staphylococcus aureus, 47.3% for penicillin-intermediate Streptococcus pneumoniae (PISP), 15.1% for penicillin-resistant S. pneumoniae (PRSP), 0.9% for extended-spectrum beta-lactamase (ESBL) producing Escherichia coli, 3.4% for ESBL producing Klebsiella pneumoniae, 19.2% for beta-lactamase producing Haemophilus influenzae, 24.0% for beta-lactamase-negative ampicillin-resistant (BLNAR) H. influenzae, and 1.0% for metallo-beta-lactamase producing Pseudomonas aeruginosa. Against these resistant strains, carbapenems including PAPM showed generally more potent activity than cephems. It was noted that PAPM showed the most potent activity against PISP and PRSP, which showed high incidence of 62.4% totally, among tested drugs. Metallo-beta-lactamase producing P. aeruginosa exhibited high resistance and BLNAR H. influenzae also exhibited low susceptibility against all tested drugs. But no remarkable change in the activity of PAPM against other species

RbsB (NTHI_0632) mediates quorum signal uptake in nontypeable Haemophilus influenzae strain 86-028NP.

Science.gov (United States)

Armbruster, Chelsie E; Pang, Bing; Murrah, Kyle; Juneau, Richard A; Perez, Antonia C; Weimer, Kristin E D; Swords, W Edward

2011-11-01

Nontypeable Haemophilus influenzae (NTHI) is a respiratory commensal and opportunistic pathogen, which persists within biofilms on airway mucosal surfaces. For many species, biofilm formation is impacted by quorum signalling. Our prior work shows that production of autoinducer-2 (AI-2) promotes biofilm development and persistence for NTHI 86-028NP. NTHI 86-028NP encodes an ABC transporter annotated as a ribose transport system that includes a protein (RbsB) with similarity to the Escherichia coli LsrB and Aggregatibacter actinomycetemcomitans RbsB proteins that bind AI-2. In this study, inactivation of rbsB significantly reduced uptake of AI-2 and the AI-2 precursor dihydroxypentanedione (DPD) by NTHI 86-028NP. Moreover, DPD uptake was not competitively inhibited by ribose or other pentose sugars. Transcript levels of rbsB increased in response to DPD and as bacteria approached stationary-phase growth. The NTHI 86-028NP rbsB mutant also formed biofilms with significantly reduced thickness and total biomass and reduced surface phosphorylcholine, similar to a luxS mutant. Infection studies revealed that loss of rbsB impaired bacterial persistence in the chinchilla middle ear, similar to our previous results with luxS mutants. Based on these data, we conclude that in NTHI 86-028NP, RbsB is a LuxS/AI-2 regulated protein that is required for uptake of and response to AI-2. © 2011 Blackwell Publishing Ltd.

Epidemiology and antibiotic resistance of bacterial meningitis in Dapaong, northern Togo

Institute of Scientific and Technical Information of China (English)

Simplice D Karou; Abago Balaka; Mitiname Bamok; Damhan Tchelougou; Malki Assih; Kokou Anani; Kodjo Agbonoko; Jacques Simpore; Comlan de Souza

2012-01-01

Objective:To assess the seasonality of the bacterial meningitis and the antibiotic resistance of incriminated bacteria over the last three years in the northern Togo. Methods: From January 2007 to January 2010, 533 cerebrospinal fluids (CSF) samples were collected from patients suspected of meningitis in the Regional Hospital of Dapaong (northern Togo). After microscopic examination, samples were cultured for bacterial identification and antibiotic susceptibility. Results:The study included 533 patients (306 male and 227 female) aged from 1 day to 55 years [average age (13.00±2.07) years]. Bacterial isolation and identification were attempted for 254/533 (47.65%) samples. The bacterial species identified were:Neisseria meningitidis A (N. meningitidis A) (58.27%), Neisseria meningitidis W135 (N. meningitidis W135) (7.09%), Streptococcus pneumoniae (S. pneumoniae) (26.77%), Haemophilus influenza B (H. influenza B) (6.30%) and Enterobacteriaceae (1.57%). The results indicated that bacterial meningitis occur from November to May with a peak in February for H. influenzae and S. pneumoniae and March for Neisseriaceae. The distribution of positive CSF with regards to the age showed that subjects between 6 and 12 years followed by subjects of 0 to 5 years were most affected with respective frequencies of 67.82% and 56.52% (P20%for both bacterial strains), macrolides (resistance rate> 30%for H. influenzae) quinolones (resistance rate>15%for H. influenzae and N. meningitidis W135). Over three years, the prevalence of S. pneumoniae significantly increased from 8.48%to 73.33%(P<0.001), while the changes in the prevalence of H. influenzae B were not statistically significant: 4.24%, vs. 8.89%, (P= 0.233). Conclusions:Our results indicate that data in African countries differ depending on geographical location in relation to the African meningitis belt. This underlines the importance of epidemiological surveillance of bacterial meningitis.

Characterization of antimicrobial resistance genes in Haemophilus parasuis isolated from pigs in China.

Science.gov (United States)

Zhao, Yongda; Guo, Lili; Li, Jie; Huang, Xianhui; Fang, Binghu

2018-01-01

Haemophilus parasuis is a common porcine respiratory pathogen that causes high rates of morbidity and mortality in farmed swine. We performed a molecular characterization of antimicrobial resistance genes harbored by H. parasuis from pig farms in China. We screened 143 H. parasuis isolates for antimicrobial susceptibility against six fluoroquinolone antibiotics testing by the broth microdilution method, and the presence of 64 antimicrobial resistance genes by PCR amplification and DNA sequence analysis. We determined quinolone resistance determining region mutations of DNA gyrase ( gyrA and gyrB ) and topoisomerase IV ( parC and parE ). The genetic relatedness among the strains was analyzed by pulsed-field gel electrophoresis. Susceptibility test showed that all isolates were low resistance to lomefloxacin (28.67%), levofloxacin (20.28%), norfloxacin (22.38%), ciprofloxacin (23.78%), however, high resistance levels were found to nalidixic acid (82.52%) and enrofloxacin (55.94%). In addition, we found 14 antimicrobial resistance genes were present in these isolates, including bla TEM-1 , bla ROB-1 , ermB, ermA, flor, catl, tetB, tetC, rmtB, rmtD, aadA1, aac(3')-llc, sul1, and sul2 genes. Interestingly, one isolate carried five antibiotic resistance genes ( tetB, tetC, flor, rmtB, sul1 ). The genes tetB , rmtB, and flor were the most prevalent resistance genes in H. parasuis in China. Alterations in the gyrA gene (S83F/Y, D87Y/N/H/G) were detected in 81% of the strains and parC mutations were often accompanied by a gyrA mutation. Pulsed-field gel electrophoresis typing revealed 51 unique patterns in the isolates carrying high-level antibiotic resistance genes, indicating considerable genetic diversity and suggesting that the genes were spread horizontally. The current study demonstrated that the high antibiotic resistance of H. parasuis in piglets is a combination of transferable antibiotic resistance genes and multiple target gene mutations. These data provide novel

QseC Mediates Osmotic Stress Resistance and Biofilm Formation in Haemophilus parasuis

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Lvqin He

2018-02-01

Full Text Available Haemophilus parasuis is known as a commensal organism discovered in the upper respiratory tract of swine where the pathogenic bacteria survive in various adverse environmental stress. QseC, a histidine protein kinase of the two-component regulatory systems CheY/QseC, is involved in the environmental adaptation in bacteria. To investigate the role of QseC in coping with the adverse environment stresses and survive in the host, we constructed a qseC mutant of H. parasuis serovar 13 strain (ΔqseC, MY1902. In this study, we found that QseC was involved in stress tolerance of H. parasuis, by the ΔqseC exhibited a decreased resistance to osmotic pressure, oxidative stress, and heat shock. Moreover, the ΔqseC weakened the ability to take up iron and biofilm formation. We also found that the QseC participate in sensing the epinephrine in environment to regulate the density of H. parasuis.

Development and Validation of a Multiplex PCR-Based Assay for the Upper Respiratory Tract Bacterial Pathogens Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis.

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Post; White; Aul; Zavoral; Wadowsky; Zhang; Preston; Ehrlich

1996-06-01

Background: Conventional simplex polymerase chain reaction (PCR)-based assays are limited in that they only provide for the detection of a single infectious agent. Many clinical diseases, however, present in a nonspecific, or syndromic, fashion, thereby necessitating the simultaneous assessment of multiple pathogens. Panel-based molecular diagnostic testing can be accomplished by the development of multiplex PCR-based assays, which can detect, individually or severally, different pathogens that are associated with syndromic illness. As part of a larger program of panel development, an assay that can simultaneously detect Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis was developed. These organisms were chosen as they are the most common bacterial pathogens associated with both the acute and chronic forms of otitis media; they are also responsible for a high percentage of sinus infections in both children and adults. In addition, H. influenzae and S. pneumoniae are commonly associated with septic meningitits. Methods and Results: Multiple individual PCR-based assays were developed for each of the three target organisms which were then evaluated for sensitivity and specificity. Utilizing the simplex assays that met our designated performance criteria, a matrix style approach was used to develop a duplex H. influenzae-S. pneumoniae assay. The duplex assay was then used as a single component in the development of a triplex assay, wherein the various M. catarrhalis primer-probe sets were tested for compatibility with the existing assay. A single-step PCR protocol, with species-specific primers for each of the three target organisms and a liquid hybridization-gel retardation amplimer detection system, was developed, which amplifies and then discriminates among each of the amplification products according to size. This assay is able to detect all three organisms in a specific manner, either individually or severally. Dilutional experiments

Haemophilus influenzae Type b disease among Amish children in Pennsylvania: reasons for persistent disease.

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Fry, A M; Lurie, P; Gidley, M; Schmink, S; Lingappa, J; Fischer, M; Rosenstein, N E

2001-10-01

To identify reservoirs of Haemophilus influenzae type b (Hib) pharyngeal carriage and assess barriers to vaccination among 2 Amish communities in Pennsylvania. We investigated recent cases, performed community surveys for Hib vaccination coverage and pharyngeal carriage, and administered a questionnaire assessing vaccination knowledge and attitudes to 298 members of 2 Amish communities (A and B) in Pennsylvania and, as a comparison group, 136 non-Amish family members who participated in state immunization clinics. From December 1999 to February 2000, 8 cases of invasive Hib disease occurred among children who were 5 years of age or younger in Pennsylvania. Six of the case-patients were from Amish communities. None of the children had been vaccinated. Among children who were 5 years of age or younger, Hib vaccine coverage was low in the 2 Amish communities: A (9 [28%] of 32) and B (3 [7%] of 41) compared with the non-Amish group (19 [95%] of 20). Hib carriage prevalence was higher in both Amish communities than in the non-Amish group (A: 3%; B: 8%; non-Amish: 0%). More households in community B had 1 or more Hib carriers than in community A (8 [28%] of 29 vs 3 [9%] of 32). Among Amish parents who did not vaccinate their children, only 25% (13 of 51) identified either religious or philosophical objections as a factor; 51% (26 of 51) reported that vaccinating was not a priority compared with other activities of daily life. Seventy-three percent (36 of 49) would vaccinate their children if vaccination were offered locally. Undervaccinated communities in the United States still exist and allow circulation of Hib strains, resulting in disease among susceptible children. Identification of undervaccinated populations, such as the Amish, and targeted education and vaccination campaigns are essential to achieving elimination of Hib disease.

The timing and targeting of treatment in influenza pandemics influences the emergence of resistance in structured populations.

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Althouse, Benjamin M; Patterson-Lomba, Oscar; Goerg, Georg M; Hébert-Dufresne, Laurent

2013-01-01

Antiviral resistance in influenza is rampant and has the possibility of causing major morbidity and mortality. Previous models have identified treatment regimes to minimize total infections and keep resistance low. However, the bulk of these studies have ignored stochasticity and heterogeneous contact structures. Here we develop a network model of influenza transmission with treatment and resistance, and present both standard mean-field approximations as well as simulated dynamics. We find differences in the final epidemic sizes for identical transmission parameters (bistability) leading to different optimal treatment timing depending on the number initially infected. We also find, contrary to previous results, that treatment targeted by number of contacts per individual (node degree) gives rise to more resistance at lower levels of treatment than non-targeted treatment. Finally we highlight important differences between the two methods of analysis (mean-field versus stochastic simulations), and show where traditional mean-field approximations fail. Our results have important implications not only for the timing and distribution of influenza chemotherapy, but also for mathematical epidemiological modeling in general. Antiviral resistance in influenza may carry large consequences for pandemic mitigation efforts, and models ignoring contact heterogeneity and stochasticity may provide misleading policy recommendations.

Basic Characterization of Natural Transformation in a Highly Transformable Haemophilus parasuis Strain SC1401

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Dai, Ke; He, Lvqin; Chang, Yung-Fu; Cao, Sanjie; Zhao, Qin; Huang, Xiaobo; Wu, Rui; Huang, Yong; Yan, Qigui; Han, Xinfeng; Ma, Xiaoping; Wen, Xintian; Wen, Yiping

2018-01-01

Haemophilus parasuis causes Glässer's disease and pneumonia, incurring serious economic losses in the porcine industry. In this study, natural competence was investigated in H. parasuis. We found competence genes in H. parasuis homologous to ones in Haemophilus influenzae and a high consensus battery of Sxy-dependent cyclic AMP (cAMP) receptor protein (CRP-S) regulons using bioinformatics. High rates of natural competence were found from the onset of stationary-phase growth condition to mid-stationary phase (OD600 from 0.29 to 1.735); this rapidly dropped off as cells reached mid-stationary phase (OD600 from 1.735 to 1.625). As a whole, bacteria cultured in liquid media were observed to have lower competence levels than those grown on solid media plates. We also revealed that natural transformation in this species is stable after 200 passages and is largely dependent on DNA concentration. Transformation competition experiments showed that heterogeneous DNA cannot outcompete intraspecific natural transformation, suggesting an endogenous uptake sequence or other molecular markers may be important in differentiating heterogeneous DNA. We performed qRT-PCR targeting multiple putative competence genes in an effort to compare bacteria pre-cultured in TSB++ vs. TSA++ and SC1401 vs. SH0165 to determine expression profiles of the homologs of competence-genes in H. influenzae. Taken together, this study is the first to investigate natural transformation in H. parasuis based on a highly naturally transformable strain SC1401. PMID:29473023

Bat lung epithelial cells show greater host species-specific innate resistance than MDCK cells to human and avian influenza viruses.

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Slater, Tessa; Eckerle, Isabella; Chang, Kin-Chow

2018-04-10

With the recent discovery of novel H17N10 and H18N11 influenza viral RNA in bats and report on high frequency of avian H9 seroconversion in a species of free ranging bats, an important issue to address is the extent bats are susceptible to conventional avian and human influenza A viruses. To this end, three bat species (Eidolon helvum, Carollia perspicillata and Tadarida brasiliensis) of lung epithelial cells were separately infected with two avian and two human influenza viruses to determine their relative host innate immune resistance to infection. All three species of bat cells were more resistant than positive control Madin-Darby canine kidney (MDCK) cells to all four influenza viruses. TB1-Lu cells lacked sialic acid α2,6-Gal receptors and were most resistant among the three bat species. Interestingly, avian viruses were relatively more replication permissive in all three bat species of cells than with the use of human viruses which suggest that bats could potentially play a role in the ecology of avian influenza viruses. Chemical inhibition of the JAK-STAT pathway in bat cells had no effect on virus production suggesting that type I interferon signalling is not a major factor in resisting influenza virus infection. Although all three species of bat cells are relatively more resistant to influenza virus infection than control MDCK cells, they are more permissive to avian than human viruses which suggest that bats could have a contributory role in the ecology of avian influenza viruses.

Economic Evaluation and Budget Impact Analysis of Vaccination against Haemophilus influenzae Type b Infection in Thailand

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Surachai Kotirum

2017-11-01

Full Text Available Current study aimed to estimate clinical and economic outcomes of providing the Haemophilus influenzae type b (Hib vaccination as a national vaccine immunization program in Thailand. A decision tree combined with Markov model was developed to simulate relevant costs and health outcomes covering lifetime horizon in societal and health care payer perspectives. This analysis considered children aged under 5 years old whom preventive vaccine of Hib infection are indicated. Two combined Hib vaccination schedules were considered: three-dose series (3 + 0 and three-dose series plus a booster does (3 + 1 compared with no vaccination. Budget impact analysis was also performed under Thai government perspective. The outcomes were reported as Hib-infected cases averted and incremental cost-effectiveness ratios (ICERs in 2014 Thai baht (THB ($ per quality-adjusted life year (QALY gained. In base-case scenario, the model estimates that 3,960 infected cases, 59 disability cases, and 97 deaths can be prevented by national Hib vaccination program. The ICER for 3 + 0 schedule was THB 1,099 ($34 per QALY gained under societal perspective. The model was sensitive to pneumonia incidence among aged under 5 years old and direct non-medical care cost per episode of Hib pneumonia. Hib vaccination is very cost-effective in the Thai context. The budget impact analysis showed that Thai government needed to invest an additional budget of 110 ($3.4 million to implement Hib vaccination program. Policy makers should consider our findings for adopting this vaccine into national immunization program.

No evidence of increasing Haemophilus influenzae non-b infection in Australian Aboriginal children

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Robert I. Menzies

2013-08-01

Full Text Available Background. High, or increasing, rates of invasive Haemophilus influenzae (Hi type a disease have been reported from North American native children from circumpolar regions, raising the question of serotype replacement being driven by vaccination against Hi type b (Hib. Indigenous Australians from remote areas had high rates of invasive Hib disease in the past, comparable to those in North American Indigenous populations. Objective. Evaluate incidence rates of invasive Hi (overall and by serotype in Indigenous Australian children over time. Design. Descriptive study of Hi incidence rates by serotype, in the Northern Territory (NT and South Australia (SA from 2001 to 2011. Comparison of NT data with a study that was conducted in the NT in 1985–1988, before Hib vaccine was introduced. Results. The average annual rate of invasive Hi type a (Hia disease in Indigenous children aged <5 years was 11/100,000 population. Although the incidence of Hi infection in Indigenous children in 2001–2003 was lower than during 2004–2011, this may be due to changes in surveillance. No other trend over time in individual serotypes or total invasive Hi disease, in Indigenous or non-Indigenous people, was identified. Compared to 1985–1988, rates in 2001–2011 were lower in all serotype groupings, by 98% for Hib, 75% for Hia, 79% for other serotypes and 67% for non-typeable Hi. Conclusions. There is no evidence of increases in invasive disease due to Hia, other specific non-b types, or non-typeable Hi in Australian Indigenous children. These data suggest that the increase in Hia some time after the introduction of Hib vaccine, as seen in the North American Arctic Region, is not common to all populations with high pre-vaccine rates of invasive Hib disease. However, small case numbers and the lack of molecular subtyping and PCR confirmation of pre-vaccine results complicate comparisons with North American epidemiology.

Prevalence and antimicrobial resistance pattern of bacterial meningitis in Egypt

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Shaban Lamyaa

2009-09-01

Full Text Available Abstract Infectious diseases are the leading cause of morbidity and mortality in the developing world. In Egypt bacterial diseases constitute a great burden, with several particular bacteria sustaining the leading role of multiple serious infections. This article addresses profound bacterial agents causing a wide array of infections including but not limited to pneumonia and meningitis. The epidemiology of such infectious diseases and the prevalence of Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae are reviewed in the context of bacterial meningitis. We address prevalent serotypes in Egypt, antimicrobial resistance patterns and efficacy of vaccines to emphasize the importance of periodic surveillance for appropriate preventive and treatment strategies.

Correlación entre la tipificación capsular de aislamientos colombianos de Haemophilus influenzae por el método de aglutinación en lámina y la técnica de PCR.

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Marylin Hidalgo

2003-06-01

Full Text Available En 1998 se inició en Colombia la inmunización de niños menores de un año de edad con la vacuna conjugada contra Haemophilus influenzae, serotipo b. En el 2000, el programa de vigilancia del Grupo de Microbiología del Instituto Nacional de Salud informó una disminución de 40% de los casos de meningitis por este microorganismo, la cual se atribuyó a la vacunación. En este programa de vigilancia se utiliza de rutina la técnica estandarizada de aglutinación en lámina para la tipificación capsular de H. influenzae. El objetivo de este trabajo fue establecer la concordancia entre la prueba de aglutinación en lámina y la técnica de PCR. Se estudiaron con ambas técnicas 146 aislamientos clínicos invasores de H. influenzae, obtenidos de niños menores de 5 años, recolectados a partir de 1999 hasta 2002, identificados y serotipificados por el laboratorio de referencia como parte de la vigilancia de la meningitis bacteriana aguda y la infección respiratoria aguda. Nuestros resultados mostraron una correlación de 93% en la tipificación capsular de H. influenzae, serotipo b, y de 92% con respecto al resto de serotipos. La técnica de aglutinación en lámina realizada con un estricto control de calidad continúa siendo una herramienta sensible y específica para la serotipificación de H. influenzae.

[Invasive infections caused by Haemophilus influenzae type b after the institution of the conjugated vaccine on the expanded programm on immunization in Chile].

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Cruces R, Pablo; Donoso F, Alejandro; Camacho A, Jorge; Llorente H, Marcela

2006-03-01

After almost a decade since the introduction of Haemophilus influenzae type b (Hib) conjugate vaccines in Chile (in a 2-4-6 month schedule), Hib invasive infections have dramatically decreased, albeit they remain to occasionally produce disease in pediatric patients. We report our experience with children whom developed Hib invasive disease in children since 2000 to 2004. Medical records of children with Hib were reviewed in order to describe the epidemiology, main clinical and laboratory findings, management and complications. Twenty three patients (17 male), between 1 and 71 months (median 30 months) were identified: pneumonia (7), meningitis (4), pleuropneumonia (2), empyema (2), sepsis (2), cellulitis (2), meningitis and pleuropneumonia (1), purpura fulminans (1), miositis (1) and epiglottitis (1). No deaths were observed and four patients presented severe sequelae at hospital discharge. Twenty patients were considered vaccine failures. Hib remains as a sporadic cause of severe disease in Chile and thus for physicians should still keep it in mind. Case analysis and active surveillance are necessary to monitor the current immunization regimen.

Characterization of antimicrobial resistance genes in Haemophilus parasuis isolated from pigs in China

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Yongda Zhao

2018-04-01

Full Text Available Background Haemophilus parasuis is a common porcine respiratory pathogen that causes high rates of morbidity and mortality in farmed swine. We performed a molecular characterization of antimicrobial resistance genes harbored by H. parasuis from pig farms in China. Methods We screened 143 H. parasuis isolates for antimicrobial susceptibility against six fluoroquinolone antibiotics testing by the broth microdilution method, and the presence of 64 antimicrobial resistance genes by PCR amplification and DNA sequence analysis. We determined quinolone resistance determining region mutations of DNA gyrase (gyrA and gyrB and topoisomerase IV (parC and parE. The genetic relatedness among the strains was analyzed by pulsed-field gel electrophoresis. Results Susceptibility test showed that all isolates were low resistance to lomefloxacin (28.67%, levofloxacin (20.28%, norfloxacin (22.38%, ciprofloxacin (23.78%, however, high resistance levels were found to nalidixic acid (82.52% and enrofloxacin (55.94%. In addition, we found 14 antimicrobial resistance genes were present in these isolates, including blaTEM-1, blaROB-1, ermB, ermA, flor, catl, tetB, tetC, rmtB, rmtD, aadA1, aac(3′-llc, sul1, and sul2 genes. Interestingly, one isolate carried five antibiotic resistance genes (tetB, tetC, flor, rmtB, sul1. The genes tetB, rmtB, and flor were the most prevalent resistance genes in H. parasuis in China. Alterations in the gyrA gene (S83F/Y, D87Y/N/H/G were detected in 81% of the strains and parC mutations were often accompanied by a gyrA mutation. Pulsed-field gel electrophoresis typing revealed 51 unique patterns in the isolates carrying high-level antibiotic resistance genes, indicating considerable genetic diversity and suggesting that the genes were spread horizontally. Discussion The current study demonstrated that the high antibiotic resistance of H. parasuis in piglets is a combination of transferable antibiotic resistance genes and multiple target

Patterns of binding of aluminum-containing adjuvants to Haemophilus influenzae type b and meningococcal group C conjugate vaccines and components

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Otto, Robert B.D.; Burkin, Karena; Amir, Saba Erum; Crane, Dennis T.; Bolgiano, Barbara

2015-01-01

The basis of Haemophilus influenzae type b (Hib) and Neisseria meningitidis serogroup C (MenC) glycoconjugates binding to aluminum-containing adjuvants was studied. By measuring the amount of polysaccharide and protein in the non-adsorbed supernatant, the adjuvant, aluminum phosphate, AlPO4, was found to be less efficient than aluminum hydroxide, Al(OH)3 at binding to the conjugates, at concentrations relevant to licensed vaccine formulations and when equimolar. At neutral pH, binding of TT conjugates to AlPO4 was facilitated through the carrier protein, with only weak binding of AlPO4 to CRM197 being observed. There was slightly higher binding of either adjuvant to tetanus toxoid conjugates, than to CRM197 conjugates. This was verified in AlPO4 formulations containing DTwP–Hib, where the adsorption of TT-conjugated Hib was higher than CRM197-conjugated Hib. At neutral pH, the anionic Hib and MenC polysaccharides did not appreciably bind to AlPO4, but did bind to Al(OH)3, due to electrostatic interactions. Phosphate ions reduced the binding of the conjugates to the adjuvants. These patterns of adjuvant adsorption can form the basis for future formulation studies with individual and combination vaccines containing saccharide-protein conjugates. PMID:26194164

Role of nutrient limitation and stationary-phase existence in Klebsiella pneumoniae biofilm resistance to ampicillin and ciprofloxacin.

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Anderl, Jeff N; Zahller, Jeff; Roe, Frank; Stewart, Philip S

2003-04-01

Biofilms formed by Klebsiella pneumoniae resisted killing during prolonged exposure to ampicillin or ciprofloxacin even though these agents have been shown to penetrate bacterial aggregates. Bacteria dispersed from biofilms into medium quickly regained most of their susceptibility. Experiments with free-floating bacteria showed that stationary-phase bacteria were protected from killing by either antibiotic, especially when the test was performed in medium lacking carbon and nitrogen sources. These results suggested that the antibiotic tolerance of biofilm bacteria could be explained by nutrient limitation in the biofilm leading to stationary-phase existence of at least some of the cells in the biofilm. This mechanism was supported by experimental characterization of nutrient availability and growth status in biofilms. The average specific growth rate of bacteria in biofilms was only 0.032 h(-1) compared to the specific growth rate of planktonic bacteria of 0.59 h(-1) measured in the same medium. Glucose did not penetrate all the way through the biofilm, and oxygen was shown to penetrate only into the upper 100 micro m. The specific catalase activity was elevated in biofilm bacteria to a level similar to that of stationary-phase planktonic cells. Transmission electron microscopy revealed that bacteria were affected by ampicillin near the periphery of the biofilm but were not affected in the interior. Taken together, these results indicate that K. pneumoniae in this system experience nutrient limitation locally within the biofilm, leading to zones in which the bacteria enter stationary phase and are growing slowly or not at all. In these inactive regions, bacteria are less susceptible to killing by antibiotics.

Vigilancia de serotipos en infecciones invasivas por Haemophilus influenzae en la Argentina en la era de la vacuna conjugada contra el serotipo b durante el período 2005-2010

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Adriana M. Efron

Full Text Available La introducción de la vacuna contra Haemophilus influenzae tipo b en los programas de inmunización de muchos países produjo una reducción marcada en la incidencia de enfermedad invasiva causada por este serotipo y en su portación y un incremento de otros tipos capsulares y de aislamientos no capsulados. Se estudiaron 313 aislamientos de H. influenzae recuperados de sitio estéril, provenientes de pacientes pediátricos y adultos con enfermedad invasiva atendidos en 90 hospitales de la Red Nacional de Laboratorios para Meningitis e Infecciones Respiratorias Agudas Bacterianas durante el período 2005-2010. Las patologías más frecuentes fueron neumonía, 40,3 % (n = 126, meningitis, 30,0 % (n = 94 y bacteriemia, 26,5 % (n = 83. En los pacientes pediátricos (n = 279, la mayor frecuencia de aislamientos correspondió a menores de 2 años, 74,5 % (n = 208. Con respecto a la distribución de tipos, el 61,3 %, correspondió a H. influenzae no capsulados (n = 192; el 20,1 % al b (n = 63; 11,2 % al a (n = 35; 4,8 % al f y 2,6 % a otros. En meningitis predominaron H. influenzae capsulados mientras que en neumonía y bacteriemia resultaron dominantes los tipos no capsulados. Se determinó el biotipo en 306 aislamientos. Todos los aislamientos de tipo a correspondieron al biotipo II; el 66,7 % de los tipo b pertenecieron al biotipo I. Mediante las técnicas de aglutinación en lámina y PCR se estudiaron 220 aislamientos; la concordancia entre ambas fue de 0,982 (IC: 0,92-1,00. En el último año se encontró un aumento significativo del tipo b, lo cual indica la importancia de mantener la vigilancia clínica y laboratorial de la enfermedad invasiva por H. influenzae.

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

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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...

The cytolethal distending toxin of Haemophilus ducreyi aggravates dermal lesions in a rabbit model of chancroid.

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Wising, Catharina; Mölne, Lena; Jonsson, Ing-Marie; Ahlman, Karin; Lagergård, Teresa

2005-05-01

Haemophilus ducreyi, the etiologic agent of the sexually transmitted disease chancroid, produces a cytolethal distending toxin (HdCDT) that inhibits cultured cell proliferation, leading to cell death. A rabbit model of dermal infection was used to investigate the roles of H. ducreyi bacteria and HdCDT in the development, clinical appearance, and persistence of infection. A non-toxin producing H. ducreyi strain, and for comparison purposes a non-capsulated Haemophilus influenzae strain, were inoculated intradermally, with and without co-administration of purified HdCDT. Co-administration of HdCDT resulted in significant aggravation of H. ducreyi-induced inflammatory lesions, and development of ulcers in rabbit skin. Less pronounced inflammatory lesions and lack of epithelial eruption were observed after inoculation with H. influenzae. Histopathological sections of the H. ducreyi-induced lesions, in both the presence and absence of HdCDT, showed dense infiltrates of the same type inflammatory cells, with the exception of a prominent endothelial cell proliferation noted in sections from lesions caused by H. ducreyi and toxin. Signs of chronic inflammation with involvement of T cells, macrophages, eosinophils, and granuloma formation were observed after H. ducreyi inoculation both with and without toxin. In conclusion, H. ducreyi causes a pronounced, chronic inflammation with involvement of T cells and macrophages, and in combination with HdCDT production of ulcers in the rabbit model. These pathogenic mechanisms may promote the development and persistence of chancroid ulcers.

Aislamientos invasivos de Haemophilus influenzae en menores de 5 años: distribución de los serotipos y de la sensibilidad antimicrobiana, SIREVA II, Colombia 2002-2013

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Mabel Karina Rodríguez

Full Text Available Objetivo: Analizar del 2002 al 2013 los datos de la vigilancia de los serotipos y sensibilidad antimicrobiana de los aislamientos invasivos de Haemophilus influenzae ( H. influenzae en niños menores de 60 meses. Materiales y métodos: Se analizaron los datos demográficos, fuente y enfermedad asociada de los aislamientos invasivos de H. influenzae recibidos entre 2002 y 2013. Todos los aislamientos habían sido confirmados bacteriológicamente, tenían el dato del serotipo, el cual fue determinado por el método de aglutinación en lámina y PCR y los patrones de sensibilidad antimicrobiana por concentración inhibitoria mínima a ampicilina, SXT, cloranfenicol, cefuroxima y ceftriaxona. El análisis se realizó por periodos de 3 años. Resultados: Por enfermedad invasiva el 50,5% eran de pacientes con meningitis, 23,5% de neumonías, 19,5% de sepsis y bacteriemia, 2,0% de otros y 4,5% sin dato. Por procedencia se recibieron de Bogotá y Antioquia 55 aislamientos de cada uno, de Risaralda 24, de Valle 15, de Santander 11 y 40 de 14 departamentos. El serotipo predominante fue el Hib (40,5%, seguido de HiNT (38,0%, Hia (17,5%, Hid (2,0%, Hif (1,5% y Hie (0,5%. Del total de los aislamientos, 12,0% eran resistentes a ampicilina; 16,5% a SXT; 1,0% a cloranfenicol y 0,5% a ceftriaxona. Todos los aislamientos fueron sensibles a cefuroxima y a rifampicina. Conclusiones: La vigilancia por el laboratorio es una vigilancia pasiva voluntaria pero, no obstante el número reducido de aislamientos, permite determinar que Hib continúa circulando en esta población y que hay otros serotipos de H. influenzae que causan enfermedad invasiva. Por tanto es necesario mantener y fortalecer la vigilancia de este patógeno.

Asymtomatic carriage of Neisseria meningitidis and Neisseria lactamica in relation to Streptococcus pneumoniae and Haemophilus influenzae colonization in healthy children: Apropos of 1400 children sampled

International Nuclear Information System (INIS)

Bakir, Mustafa; Yagci, Aysegul; Ulger, Nurver; Akbenlioglu, Cengiz; Ilki, Arzu; Soyletir, Guner

2001-01-01

Meningococcal disease is one of the most important causes of morbidity and mortality among children in many parts of the world. Main reservoir of carriage and site of meningococcal dissemination appears to be the upper respiratory tract. Colonization of Neisseria meningitidis and lactamica and factors affecting this carriage were determined in a group of healthy children aged 0-10 years. Meningococcus and N. lactamica carriage were detected in 17 (1.23%) and 245 (17.7%) of 1382 subjects, respectively. Number (%) of serogroups for meningococci was 1 (6), 5 (29), 0 (0), 1 (6), 1 (6), and 9 (53) for A, B, C, D, W135, and Y, respectively. Having more than three household members, elementary school attendance, pharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae were associated with carriage of meningococci, whereas age less than 24-month was associated with carriage of N. lactamica. There was a reverse carriage rate between N. meningitidis and N. lactamica by age which may suggest a possible protective role of N. lactamica against meningococcal colonization among pre-school children

Simultaneous delivery of antibiotics neomycin and ampicillin in drinking water inhibits fermentation of resistant starch in rats.

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Carvajal-Aldaz, Diana G; Guice, Justin L; Page, Ryan C; Raggio, Anne M; Martin, Roy J; Husseneder, Claudia; Durham, Holiday A; Geaghan, James; Janes, Marlene; Gauthier, Ted; Coulon, Diana; Keenan, Michael J

2017-03-01

Antibiotics ampicillin 1 g/L and neomycin 0.5 g/L were added to drinking water before or during feeding of resistant starch (RS) to rats to inhibit fermentation. In a preliminary study, antibiotics and no RS were given prior to rats receiving a transplant of cecal contents via gavage from donor rats fed RS (without antibiotics) or a water gavage before feeding resistant starch to both groups. Antibiotics given prior to feeding RS did not prevent later fermentation of RS regardless of either type of gavage. In the second study, antibiotics were given simultaneously with feeding of RS. This resulted in inhibition of fermentation of RS with cecal contents pH >8 and low amounts of acetate and butyrate. Rats treated with antibiotics had reduced Bifidobacteria spp., but similar Bacteroides spp. to control groups to reduce acetate and butyrate and preserve the production of propionate. Despite reduced fermentation, rats given antibiotics had increased glucagon-like peptide 1 (GLP-1) and cecum size, measures that are usually associated with fermentation. A simultaneous delivery of antibiotics inhibited fermentation of RS. However, increased GLP-1 and cecum size would be confounding effects in assessing the mechanism for beneficial effects of dietary RS by knocking out fermentation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ampicillin and Sulbactam Injection

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... in a class of medications called penicillin-like antibiotics. It works by stopping the growth of bacteria. Sulbactam is ... It works by preventing bacteria from destroying ampicillin. Antibiotics will not work for colds, flu, or other viral infections.

Patterns of binding of aluminum-containing adjuvants to Haemophilus influenzae type b and meningococcal group C conjugate vaccines and components.

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Otto, Robert B D; Burkin, Karena; Amir, Saba Erum; Crane, Dennis T; Bolgiano, Barbara

2015-09-01

The basis of Haemophilus influenzae type b (Hib) and Neisseria meningitidis serogroup C (MenC) glycoconjugates binding to aluminum-containing adjuvants was studied. By measuring the amount of polysaccharide and protein in the non-adsorbed supernatant, the adjuvant, aluminum phosphate, AlPO4, was found to be less efficient than aluminum hydroxide, Al(OH)3 at binding to the conjugates, at concentrations relevant to licensed vaccine formulations and when equimolar. At neutral pH, binding of TT conjugates to AlPO4 was facilitated through the carrier protein, with only weak binding of AlPO4 to CRM197 being observed. There was slightly higher binding of either adjuvant to tetanus toxoid conjugates, than to CRM197 conjugates. This was verified in AlPO4 formulations containing DTwP-Hib, where the adsorption of TT-conjugated Hib was higher than CRM197-conjugated Hib. At neutral pH, the anionic Hib and MenC polysaccharides did not appreciably bind to AlPO4, but did bind to Al(OH)3, due to electrostatic interactions. Phosphate ions reduced the binding of the conjugates to the adjuvants. These patterns of adjuvant adsorption can form the basis for future formulation studies with individual and combination vaccines containing saccharide-protein conjugates. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Dicty_cDB: Contig-U05349-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available fluenzae PittGG, complete genome. 62 2e-14 3 ( DM109591 ) HAEMOPHILUS INFLUENZAE ... ) The Nucleotide Sequence of the Haemophilus influe... 62 3e-14 3 ( DM108107 ) HAEMOPHILUS INFLUENZAE TYPE

Prolonged influenza virus shedding and emergence of antiviral resistance in immunocompromised patients and ferrets.

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Erhard van der Vries

Full Text Available Immunocompromised individuals tend to suffer from influenza longer with more serious complications than otherwise healthy patients. Little is known about the impact of prolonged infection and the efficacy of antiviral therapy in these patients. Among all 189 influenza A virus infected immunocompromised patients admitted to ErasmusMC, 71 were hospitalized, since the start of the 2009 H1N1 pandemic. We identified 11 (15% cases with prolonged 2009 pandemic virus replication (longer than 14 days, despite antiviral therapy. In 5 out of these 11 (45% cases oseltamivir resistant H275Y viruses emerged. Given the inherent difficulties in studying antiviral efficacy in immunocompromised patients, we have infected immunocompromised ferrets with either wild-type, or oseltamivir-resistant (H275Y 2009 pandemic virus. All ferrets showed prolonged virus shedding. In wild-type virus infected animals treated with oseltamivir, H275Y resistant variants emerged within a week after infection. Unexpectedly, oseltamivir therapy still proved to be partially protective in animals infected with resistant virus. Immunocompromised ferrets offer an attractive alternative to study efficacy of novel antiviral therapies.

Clinical efficacy of ampicillin in treatment of acute odontogenic abscess

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Matijević Stevo

2009-01-01

Full Text Available Background/Aim. Antibiotics choice and the duration of their application in the therapy of acute odontogenic abscess is considered to be controversial. The aim of this study was to investigate the clinical efficacy of ampicillin in treatment of acute odontogenic abscess and to assess the antimicrobial susceptibility of the isolated bacteria in early phase of abscess development. Methods. This study included 60 patients with acute odontogenic abscess who were surgically treated (extraction of teeth and/or abscess incision divided into two groups, ampicillin group and surgical group (without antibiotic treatment. Results. In the ampicillin group of patients treatment lasted on the average 4.67 days, while in the surgical group 6.17 days. A total of 78 bacterial strains were isolated from 60 patients. The most often bacteria were found to be Gram-positive facultative anaerobs (68/78. The most common bacteria isolated were Viridans streptococci (43/78. Susceptibility of isolated bacteria to ampicillin were 70.5%. Conclusion. Peroral use of ampicillin, after surgical treatment in an early phase of dentoalveolar abscess development, statistically significantly reduced the time of clinical symptoms of acute odontogenic abscess in comparison to surgical treatment only. The isolated bacterial strains in an early phase of dentoalveolar abscess development showed a high sensitivity to ampicillin.

Preclinical evaluation of a Haemophilus influenzae type b conjugate vaccine process intended for technology transfer.

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Hamidi, Ahd; Verdijk, Pauline; Kreeftenberg, Hans

2014-01-01

Introduction of Haemophilus influenzae type b (Hib) vaccine in low- and middle-income countries has been limited by cost and availability of Hib conjugate vaccines for a long time. It was previously recognized by the Institute for Translational Vaccinology (Intravacc, originating from the former Vaccinology Unit of the National Institute of Public Health [RIVM] and the Netherlands Vaccine Institute [NVI]) that local production of a Hib conjugate vaccine would increase the affordability and sustainability of the vaccine and thereby help to speed up Hib introduction in these countries. A new affordable and a non-infringing production process for a Hib conjugate vaccine was developed, including relevant quality control tests, and the technology was transferred to a number of vaccine manufacturers in India, Indonesia, and China. As part of the Hib technology transfer project managed by Intravacc, a preclinical toxicity study was conducted in the Netherlands to test the safety and immunogenicity of this new Hib conjugate vaccine. The data generated by this study were used by the technology transfer partners to accelerate the clinical development of the new Hib conjugate vaccine. A repeated dose toxicity and local tolerance study in rats was performed to assess the reactogenicity and immunogenicity of a new Hib conjugate vaccine compared to a licensed vaccine. The results showed that the vaccine was well tolerated and immunogenic in rats, no major differences in both safety and immunogenicity in rats were found between the vaccine produced according to the production process developed by Intravacc and the licensed one. Rats may be useful to verify the immunogenicity of Hib conjugate vaccines and for preclinical evaluation. In general, nonclinical evaluation of the new Hib conjugate vaccine, including this proof of concept (safety and immunogenicity study in rats), made it possible for technology transfer partners, having implemented the original process with no changes

Competitive fitness of influenza B viruses with neuraminidase inhibitor-resistant substitutions in a coinfection model of the human airway epithelium.

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Burnham, Andrew J; Armstrong, Jianling; Lowen, Anice C; Webster, Robert G; Govorkova, Elena A

2015-04-01

Influenza A and B viruses are human pathogens that are regarded to cause almost equally significant disease burdens. Neuraminidase (NA) inhibitors (NAIs) are the only class of drugs available to treat influenza A and B virus infections, so the development of NAI-resistant viruses with superior fitness is a public health concern. The fitness of NAI-resistant influenza B viruses has not been widely studied. Here we examined the replicative capacity and relative fitness in normal human bronchial epithelial (NHBE) cells of recombinant influenza B/Yamanashi/166/1998 viruses containing a single amino acid substitution in NA generated by reverse genetics (rg) that is associated with NAI resistance. The replication in NHBE cells of viruses with reduced inhibition by oseltamivir (recombinant virus with the E119A mutation generated by reverse genetics [rg-E119A], rg-D198E, rg-I222T, rg-H274Y, rg-N294S, and rg-R371K, N2 numbering) or zanamivir (rg-E119A and rg-R371K) failed to be inhibited by the presence of the respective NAI. In a fluorescence-based assay, detection of rg-E119A was easily masked by the presence of NAI-susceptible virus. We coinfected NHBE cells with NAI-susceptible and -resistant viruses and used next-generation deep sequencing to reveal the order of relative fitness compared to that of recombinant wild-type (WT) virus generated by reverse genetics (rg-WT): rg-H274Y > rg-WT > rg-I222T > rg-N294S > rg-D198E > rg-E119A ≫ rg-R371K. Based on the lack of attenuated replication of rg-E119A in NHBE cells in the presence of oseltamivir or zanamivir and the fitness advantage of rg-H274Y over rg-WT, we emphasize the importance of these substitutions in the NA glycoprotein. Human infections with influenza B viruses carrying the E119A or H274Y substitution could limit the therapeutic options for those infected; the emergence of such viruses should be closely monitored. Influenza B viruses are important human respiratory pathogens contributing to a significant portion

Results from the Survey of Antibiotic Resistance (SOAR) 2011-13 in Ukraine.

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Feshchenko, Y; Dzyublik, A; Pertseva, T; Bratus, E; Dzyublik, Y; Gladka, G; Morrissey, I; Torumkuney, D

2016-05-01

To determine the antibiotic susceptibility of respiratory isolates of Streptococcus pneumoniae and Haemophilus influenzae collected in 2011-13 from Ukraine. MICs were determined by CLSI broth microdilution and susceptibility was assessed using CLSI, EUCAST and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints. A total of 134 isolates of S. pneumoniae and 67 of H. influenzae were collected from eight sites in Ukraine. Overall, 87.3% of S. pneumoniae were penicillin susceptible by CLSI oral breakpoints and 99.3% by CLSI iv breakpoints. Susceptibility to amoxicillin/clavulanic acid (amoxicillin), ceftriaxone and levofloxacin was 100% by CLSI and PK/PD breakpoints. Cephalosporin and macrolide susceptibility was ≥95.5% and 88.1%, respectively using CLSI breakpoints. Trimethoprim/sulfamethoxazole was essentially inactive against pneumococci. Of the 67 H. influenzae tested, 4.5% were β-lactamase positive and all H. influenzae were fully susceptible to amoxicillin/clavulanic acid, ceftriaxone, ciprofloxacin, cefixime and levofloxacin (all breakpoints). Cefuroxime susceptibility was 100% by CLSI but 73.1% by EUCAST and PK/PD breakpoints. A discrepancy was found in macrolide susceptibility between CLSI (∼100% susceptible), EUCAST (22%-43% susceptible) and PK/PD (0%-22% susceptible) breakpoints. Trimethoprim/sulfamethoxazole was poorly active (59.7% susceptible). Generally, antibiotic resistance was low in respiratory pathogens from Ukraine. However, only amoxicillin/clavulanic acid (amoxicillin), ceftriaxone and levofloxacin were fully active against both species. Trimethoprim/sulfamethoxazole was the least active, particularly against S. pneumoniae. Some susceptibility differences were apparent between CLSI, EUCAST and PK/PD breakpoints, especially with macrolides against H. influenzae. These data suggest that further efforts are required to harmonize these international breakpoints. Future studies are warranted to monitor continued low resistance levels in Ukraine

Antibacterial resistance of community-acquired respiratory tract pathogens recovered from patients in Latin America: results from the PROTEKT surveillance study (1999-2000

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Mendes C.

2003-01-01

Full Text Available PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participat ed during 1999-2000; they collected 1,806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277. Overall, 218 (42.1% of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3% were penicillin-resistant and 79 (15.3% were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5% and erythromycin (31.2% resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A, 33 possessed erm(B and 1 possessed both erm(B and mef(A mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9% produced b-lactamase, ranging from 11% (Brazil to 24.5% (Mexico. Among M. catarrhalis isolates, 138 (98.6% produced b-lactamase. Twenty-four (8.7% of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18, ermTR (n=5 and ermB (n=1. All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5% of the S. aureus isolates (Argentina 15%; Mexico 20%; Brazil 31.3%. Telithromycin was effective against 97.7% of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the b-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy.

Antibody responses to tetanus toxoid and Haemophilus influenzae type b conjugate vaccines following autologous peripheral blood stem cell transplantation (PBSCT).

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Chan, C Y; Molrine, D C; Antin, J H; Wheeler, C; Guinan, E C; Weinstein, H J; Phillips, N R; McGarigle, C; Harvey, S; Schnipper, C; Ambrosino, D M

1997-07-01

Accelerated granulocyte and platelet recovery following peripheral blood stem cell transplantation (PBSCT) are well documented. We hypothesize that functional immunity may also be enhanced in PBSCT and performed a phase II trial of immunizations in patients with lymphoma undergoing autologous transplantation with peripheral blood stem cells or bone marrow. Seventeen BMT and 10 PBSCT recipients were immunized at 3, 6, 12, and 24-months post-transplantation with Haemophilus influenzae type b (HIB)-conjugate and tetanus toxoid (TT) vaccines. IgG anti-HIB and anti-TT antibody concentrations were measured and compared between the two groups. Geometric mean IgG anti-HIB antibody concentrations were significantly higher for PBSCT recipients compared to BMT recipients at 24 months post-transplantation (11.3 micrograms/ml vs 0.93 microgram/ml, P = 0.051) and following the 24 month immunization (66.2 micrograms/ml vs 1.30 micrograms/ml, P = 0.006). Similar results were noted for IgG anti-TT antibody with significantly higher geometric mean antibody concentrations in the PBSCT group at 24 months post-transplantation (182 micrograms/ml vs 21.6 micrograms/ml, P = 0.039). Protective levels of total anti-HIB antibody were achieved earlier in PBSCT recipients compared with those of BMT recipients. PBSCT recipients had higher antigen-specific antibody concentrations following HIB and TT immunizations. These results suggest enhanced recovery of humoral immunity in PBSCT recipients and earlier protection against HIB with immunization.

Long-term trends in invasive Haemophilus influenzae type B disease among indigenous Australian children following use of PRP-OMP and PRP-T vaccines.

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Menzies, Robert Ian; Bremner, Kyla Margaret; Wang, Han; Beard, Frank Hudson; McIntyre, Peter Bruce

2015-06-01

Among indigenous populations with high incidence and early onset of invasive Haemophilus influenzae type b (Hib) disease, PRP-OMP vaccines are used in the United States and PRP-T vaccines in Canada. In Australia, PRP-OMP vaccines were exclusively used in indigenous children from 1993 until they were replaced by PRP-T between late 2005 and 2009. Analytic descriptive study of 20 years of enhanced surveillance data (1993-2013) for invasive Hib disease in Australian children PRP-OMP period (1993-1996) to 6.2 (95% CI: 4.0, 9.2) and 4.7 (95% CI: 1.7, 10.3) in the later PRP-OMP (1996-2009) and PRP-T periods (2009-2013), respectively. The indigenous:nonindigenous incidence rate ratio increased to 43 (95% CI: 16, 145) and 58 (95% CI: 7, 2660) in the later PRP-OMP and PRP-T periods, respectively, more than 10-fold higher than in lesser-incidence Australian regions. We found no change in Hib incidence among indigenous Australian children living in high-incidence regions in the first 4 years following a change to PRP-T-containing combination vaccines. This may be of relevance to North American indigenous populations characterized by suboptimal living conditions and young age of onset for whom PRP-OMP continues to be recommended, such as Alaska Natives.

Distribution and characterization of ampicillin- and tetracycline-resistant Escherichia coli from feedlot cattle fed subtherapeutic antimicrobials

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Yanke L Jay

2011-04-01

Full Text Available Abstract Background Feedlot cattle in North America are routinely fed subtherapeutic levels of antimicrobials to prevent disease and improve the efficiency of growth. This practice has been shown to promote antimicrobial resistance (AMR in subpopulations of intestinal microflora including Escherichia coli. To date, studies of AMR in feedlot production settings have rarely employed selective isolation, therefore yielding too few AMR isolates to enable characterization of the emergence and nature of AMR in E. coli as an indicator bacterium. E. coli isolates (n = 531 were recovered from 140 cattle that were housed (10 animals/pen in 14 pens and received no dietary antimicrobials (control - 5 pens, CON, or were intermittently administered subtherapeutic levels of chlortetracycline (5 pens-T, chlortetracycline + sulfamethazine (4 pens-TS, or virginiamycin (5 pens-V for two separate periods over a 9-month feeding period. Phenotype and genotype of the isolates were determined by susceptibility testing and pulsed field gel electrophoresis and distribution of characterized isolates among housed cattle reported. It was hypothesized that the feeding of subtherapeutic antibiotics would increase the isolation of distinct genotypes of AMR E. coli from cattle. Results Overall, patterns of antimicrobial resistance expressed by E. coli isolates did not change among diet groups (CON vs. antibiotic treatments, however; isolates obtained on selective plates (i.e., MA,MT, exhibited multi-resistance to sulfamethoxazole and chloramphenicol more frequently when obtained from TS-fed steers than from other treatments. Antibiograms and PFGE patterns suggested that AMR E. coli were readily transferred among steers within pens. Most MT isolates possessed the tet(B efflux gene (58.2, 53.5, 40.8, and 50.6% of isolates from CON, T, TS, and V steers, respectively whereas among the MA (ampicillin-resistant isolates, the tem1-like determinant was predominant (occurring in 50, 66

Australian Aboriginal Children with Otitis Media Have Reduced Antibody Titers to Specific Nontypeable Haemophilus influenzae Vaccine Antigens

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Kirkham, Lea-Ann S.; Corscadden, Karli J.; Wiertsema, Selma P.; Fuery, Angela; Jones, B. Jan; Coates, Harvey L.; Vijayasekaran, Shyan; Zhang, Guicheng; Keil, Anthony; Richmond, Peter C.

2017-01-01

ABSTRACT Indigenous populations experience high rates of otitis media (OM), with increased chronicity and severity, compared to those experienced by their nonindigenous counterparts. Data on immune responses to otopathogenic bacteria in these high-risk populations are lacking. Nontypeable Haemophilus influenzae (NTHi) is the predominant otopathogen in Australia. No vaccines are currently licensed to target NTHi; however, protein D (PD) from NTHi is included as a carrier protein in the 10-valent pneumococcal polysaccharide conjugate vaccine (PHiD10-CV), and other promising protein vaccine candidates exist, including outer membrane protein 4 (P4) and protein 6 (P6). We measured the levels of serum and salivary IgA and IgG against PD, P4, and P6 in Aboriginal and non-Aboriginal children with chronic OM who were undergoing surgery and compared the levels with those in healthy non-Aboriginal children (controls). We found that Aboriginal cases had lower serum IgG titers to all NTHi proteins assessed, particularly PD. In contrast, serum IgA and salivary IgA and IgG titers to each of these 3 proteins were equivalent to or higher than those in both non-Aboriginal cases and healthy controls. While serum antibody levels increased with age in healthy controls, no changes in titers were observed with age in non-Aboriginal cases, and a trend toward decreasing titers with age was observed in Aboriginal cases. This suggests that decreased serum IgG responses to NTHi outer membrane proteins may contribute to the development of chronic and severe OM in Australian Aboriginal children and other indigenous populations. These data are important for understanding the potential benefits of PHiD10-CV implementation and the development of NTHi protein-based vaccines for indigenous populations. PMID:28151410

Influenza A Subtyping

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Kaul, Karen L.; Mangold, Kathy A.; Du, Hongyan; Pesavento, Kristen M.; Nawrocki, John; Nowak, Jan A.

2010-01-01

Influenza virus subtyping has emerged as a critical tool in the diagnosis of influenza. Antiviral resistance is present in the majority of seasonal H1N1 influenza A infections, with association of viral strain type and antiviral resistance. Influenza A virus subtypes can be reliably distinguished by examining conserved sequences in the matrix protein gene. We describe our experience with an assay for influenza A subtyping based on matrix gene sequences. Viral RNA was prepared from nasopharyngeal swab samples, and real-time RT-PCR detection of influenza A and B was performed using a laboratory developed analyte-specific reagent-based assay that targets a conserved region of the influenza A matrix protein gene. FluA-positive samples were analyzed using a second RT-PCR assay targeting the matrix protein gene to distinguish seasonal influenza subtypes based on differential melting of fluorescence resonance energy transfer probes. The novel H1N1 influenza strain responsible for the 2009 pandemic showed a melting profile distinct from that of seasonal H1N1 or H3N2 and compatible with the predicted melting temperature based on the published novel H1N1 matrix gene sequence. Validation by comparison with the Centers for Disease Control and Prevention real-time RT-PCR for swine influenza A (novel H1N1) test showed this assay to be both rapid and reliable (>99% sensitive and specific) in the identification of the novel H1N1 influenza A virus strain. PMID:20595627

Combination Chemotherapy for Influenza

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Robert G. Webster

2010-07-01

Full Text Available The emergence of pandemic H1N1 influenza viruses in April 2009 and the continuous evolution of highly pathogenic H5N1 influenza viruses underscore the urgency of novel approaches to chemotherapy for human influenza infection. Anti-influenza drugs are currently limited to the neuraminidase inhibitors (oseltamivir and zanamivir and to M2 ion channel blockers (amantadine and rimantadine, although resistance to the latter class develops rapidly. Potential targets for the development of new anti-influenza agents include the viral polymerase (and endonuclease, the hemagglutinin, and the non-structural protein NS1. The limitations of monotherapy and the emergence of drug-resistant variants make combination chemotherapy the logical therapeutic option. Here we review the experimental data on combination chemotherapy with currently available agents and the development of new agents and therapy targets.

MICROBIOLOGICAL CHARACTERISATION OF Haemophilus influenzae STRAINS ISOLATED FROM PATIENTS WITH INVASIVE AND RESPIRATORY DISEASES

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Tomislav Kostyanev

2010-01-01

Full Text Available A total of 175 H. influenzae strains were collected between 1994 and 2009 from all aged patient groups. The strains were isolated from patients with invasive and community-acquired respiratory tract infections. All strains were identified according to standard microbiological methods. Serotyping was done by a coagglutination test and by molecular PCR capsular genotyping. Beta-lactamase production was determined by the chromogenic cephalosporin test with nitrocephin as substrate. Most of the isolated H. influenzae strains were from children under 5 years of age (57.7%. Overall, 61 strains belonged to serotype b (34.9% by the means of PCR capsular typing, 1 strain was type f, and 113 isolates (64.6% were non-typeable (non-encapsulated H. influenzae. Among the infants and children with meningitis or other invasive infections, aged 2 month to 5 years, all strains, except one, were serotype b. In respiratory tract infections (pneumonia, otitis media, sinusitis and people with chronic pulmonary diseases - exacerbations of COPD, bronchiectasis, cystic fibrosis the most common - 96.5% were non-typeable strains in both groups children and adults. Overall, the prevalence of beta-lactamase production was 19.4%. But, it was much higher for invasive strains from CSF isolates - 37.7%, 25% in blood samples, and 37.5% in otitis media causative strains. Beta-lactamase production was less frequent in respiratory tract isolates - in sputum 13.3% and in URT samples - 2.3%. The rate of beta-lactamase production in CSF isolates has not changed for the last 10 years.PCR capsular genotyping method has to be performed for all non-b-type strains. The implementation of Hib vaccine in our country will be accompanied by a reduction in invasive diseases caused by H. influenzae type b in children, but it is not useful in preventing infections caused by non-typeable H. influenzae strains.

Naturligt forekommende oseltamivirresistens hos influenza A

DEFF Research Database (Denmark)

Madsen, Laura; Nielsen, Alex; Lundgren, Jens

2010-01-01

in the development of resistance. The best prevention strategy remains vaccination of the general population to avoid immunity. Future antiviral treatment calls for knowledge about resistance to existing types of influenza and the availability of all three types of antiviral medication.......During the last two influenza seasons, one of the predominant influenza A types (H1N1) has developed complete resistance to oseltamivir, the primary treatment option. The virus does, however, remain sensitive to zanamavir and amantadine. There is no unequivocal explanation for this slide...

Naturligt forekommende oseltamivirresistens hos influenza A

DEFF Research Database (Denmark)

Madsen, Laura; Nielsen, Alex; Lundgren, Jens

2010-01-01

During the last two influenza seasons, one of the predominant influenza A types (H1N1) has developed complete resistance to oseltamivir, the primary treatment option. The virus does, however, remain sensitive to zanamavir and amantadine. There is no unequivocal explanation for this slide...... in the development of resistance. The best prevention strategy remains vaccination of the general population to avoid immunity. Future antiviral treatment calls for knowledge about resistance to existing types of influenza and the availability of all three types of antiviral medication....

Underutilization of Influenza Vaccine

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Marshall K. Cheney

2013-04-01

Full Text Available Yearly influenza vaccination continues to be underutilized by those who would most benefit from it. The Health Belief Model was used to explain differences in beliefs about influenza vaccination among at-risk individuals resistant to influenza vaccination. Survey data were collected from 74 members of at-risk groups who were not vaccinated for influenza during the previous flu season. Accepting individuals were more likely to perceive flu as a threat to health and perceive access barriers, and cues to action were the most important influence on whether they plan to get vaccinated. In comparison, resistant individuals did not feel threatened by the flu, access barriers were not a problem, and they did not respond favorably to cues to action. Perceived threat, perceived access barriers, and cues to action were significantly associated with plans to be vaccinated for influenza in the next flu season. Participants who saw influenza as a threat to their health had 5.4 times the odds of planning to be vaccinated than those who did not. Participants reporting barriers to accessing influenza vaccination had 7.5 times the odds of reporting plans to be vaccinated. Those responding positively to cues to action had 12.2 times the odds of planning to be vaccinated in the next flu season than those who did not. Accepting and resistant individuals have significant differences in their beliefs, which require different intervention strategies to increase vaccination rates. These findings provide important information to researchers and practitioners working to increase influenza vaccination rates.

Reassortment and mutations associated with emergence and spread of oseltamivir-resistant seasonal influenza A/H1N1 viruses in 2005-2009.

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Ji-Rong Yang

Full Text Available A dramatic increase in the frequency of the H275Y mutation in the neuraminidase (NA, conferring resistance to oseltamivir, has been detected in human seasonal influenza A/H1N1 viruses since the influenza season of 2007-2008. The resistant viruses emerged in the ratio of 14.3% and quickly reached 100% in Taiwan from September to December 2008. To explore the mechanisms responsible for emergence and spread of the resistant viruses, we analyzed the complete genome sequences of 25 viruses collected during 2005-2009 in Taiwan, which were chosen from various clade viruses, 1, 2A, 2B-1, 2B-2, 2C-1 and 2C-2 by the classification of hemagglutinin (HA sequences. Our data revealed that the dominant variant, clade 2B-1, in the 2007-2008 influenza emerged through an intra-subtype 4+4 reassortment between clade 1 and 2 viruses. The dominant variant acquired additional substitutions, including A206T in HA, H275Y and D354G in NA, L30R and H41P in PB1-F2, and V411I and P453S in basic polymerase 2 (PB2 proteins and subsequently caused the 2008-2009 influenza epidemic in Taiwan, accompanying the widespread oseltamivir-resistant viruses. We also characterized another 3+5 reassortant virus which became double resistant to oseltamivir and amantadine. Comparison of oseltamivir-resistant influenza A/H1N1 viruses belonging to various clades in our study highlighted that both reassortment and mutations were associated with emergence and spread of these viruses and the specific mutation, H275Y, conferring to antiviral resistance, was acquired in a hitch-hiking mechanism during the viral evolutionary processes.

The biofilm matrix destabilizers, EDTA and DNaseI, enhance the susceptibility of nontypeable Hemophilus influenzae biofilms to treatment with ampicillin and ciprofloxacin.

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Cavaliere, Rosalia; Ball, Jessica L; Turnbull, Lynne; Whitchurch, Cynthia B

2014-08-01

Nontypeable Hemophilus influenzae (NTHi) is a Gram-negative bacterial pathogen that causes chronic biofilm infections of the ears and airways. The biofilm matrix provides structural integrity to the biofilm and protects biofilm cells from antibiotic exposure by reducing penetration of antimicrobial compounds into the biofilm. Extracellular DNA (eDNA) has been found to be a major matrix component of biofilms formed by many species of Gram-positive and Gram-negative bacteria, including NTHi. Interestingly, the cation chelator ethylenediaminetetra-acetic acid (EDTA) has been shown to reduce the matrix strength of biofilms of several bacterial species as well as to have bactericidal activity against various pathogens. EDTA exerts its antimicrobial activity by chelating divalent cations necessary for growth and membrane stability and by destabilizing the matrix thus enhancing the detachment of bacterial cells from the biofilm. In this study, we have explored the role of divalent cations in NTHi biofilm development and stability. We have utilized in vitro static and continuous flow models of biofilm development by NTHi to demonstrate that magnesium cations enhance biofilm formation by NTHi. We found that the divalent cation chelator EDTA is effective at both preventing NTHi biofilm formation and at treating established NTHi biofilms. Furthermore, we found that the matrix destablilizers EDTA and DNaseI increase the susceptibility of NTHi biofilms to ampicillin and ciprofloxacin. Our observations indicate that DNaseI and EDTA enhance the efficacy of antibiotic treatment of NTHi biofilms. These observations may lead to new strategies that will improve the treatment options available to patients with chronic NTHi infections. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Immunogenicity of Nontypeable Haemophilus influenzae Outer Membrane Vesicles and Protective Ability in the Chinchilla Model of Otitis Media.

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Winter, Linda E; Barenkamp, Stephen J

2017-10-01

Outer membrane vesicles (OMVs) produced by Gram-negative bacteria are enriched in several outer membrane components, including major and minor outer membrane proteins and lipooligosaccharide. We assessed the functional activity of nontypeable Haemophilus influenzae (NTHi) OMV-specific antisera and the protective ability of NTHi OMVs as vaccine antigens in the chinchilla otitis media model. OMVs were purified from three HMW1/HMW2-expressing NTHi strains, two of which were also engineered to overexpress Hia proteins. OMV-specific antisera raised in guinea pigs were assessed for their ability to mediate killing of representative NTHi in an opsonophagocytic assay. The three OMV-specific antisera mediated killing of 18 of 65, 24 of 65, and 30 of 65 unrelated HMW1/HMW2-expressing NTHi strains. Overall, they mediated killing of 39 of 65 HMW1/HMW2-expressing strains. The two Hia-expressing OMV-specific antisera mediated killing of 17 of 25 and 14 of 25 unrelated Hia-expressing NTHi strains. Overall, they mediated killing of 20 of 25 Hia-expressing strains. OMVs from prototype NTHi strain 12 were used to immunize chinchillas and the course of middle ear infection was monitored following intrabullar challenge with the homologous strain. All control animals developed culture-positive otitis media, as did two of three HMW1/HMW2-immunized animals. All OMV-immunized animals, with or without supplemental HMW1/HMW2 immunization, were completely protected against otitis media. NTHi OMVs are the first immunogens examined in this model that provided complete protection with sterile immunity after NTHi strain 12 challenge. These data suggest that NTHi OMVs hold significant potential as components of protective NTHi vaccines, possibly in combination with HMW1/HMW2 proteins. Copyright © 2017 American Society for Microbiology.

Immunogenicity, safety and reactogenicity of a booster dose of the 10-valent pneumococcal Nontypeable H. influenzae Protein D conjugate vaccine coadministered with DTPa-IPV-Hib in Dutch children

NARCIS (Netherlands)

Van Den Bergh, Menno R.; Spijkerman, Judith; François, Nancy; Swinnen, Kristien; Borys, Dorota; Schuerman, Lode; Veenhoven, Reinier H.; Sanders, Elisabeth A M

2016-01-01

Background: Immune responses and safety profiles may be affected when vaccines are coadministered. We evaluated the immunogenicity, safety and reactogenicity of a booster dose of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D-conjugate (PHiD-CV; Synflorix GSK Vaccines) and

Haemophilus parasuis CpxRA two-component system confers bacterial tolerance to environmental stresses and macrolide resistance.

Science.gov (United States)

Cao, Qi; Feng, Fenfen; Wang, Huan; Xu, Xiaojuan; Chen, Huanchun; Cai, Xuwang; Wang, Xiangru

2018-01-01

Haemophilus parasuis is an opportunistic pathogen localized in the upper respiratory tracts of pigs, its infection begins from bacterial survival under complex conditions, like hyperosmosis, oxidative stress, phagocytosis, and sometimes antibiotics as well. The two-component signal transduction (TCST) system serves as a common stimulus-response mechanism that allows microbes to sense and respond to diverse environmental conditions via a series of phosphorylation reactions. In this study, we investigated the role of TCST system CpxRA in H. parasuis in response to different environmental stimuli by constructing the ΔcpxA and ΔcpxR single deletion mutants as well as the ΔcpxRA double deletion mutant from H. parasuis serotype 4 isolate JS0135. We demonstrated that H. parasuis TCST system CpxRA confers bacterial tolerance to stresses and bactericidal antibiotics. The CpxR was found to play essential roles in mediating oxidative stress, osmotic stresses and alkaline pH stress tolerance, as well as macrolide resistance (i.e. erythromycin), but the CpxA deletion did not decrease bacterial resistance to abovementioned stresses. Moreover, we found via RT-qPCR approach that HAPS_RS00160 and HAPS_RS09425, both encoding multidrug efflux pumps, were significantly decreased in erythromycin challenged ΔcpxR and ΔcpxRA mutants compared with wild-type strain JS0135. These findings characterize the role of the TCST system CpxRA in H. parasuis conferring stress response tolerance and bactericidal resistance, which will deepen our understanding of the pathogenic mechanism in H. parasuis. Copyright © 2017 Elsevier GmbH. All rights reserved.

Comparative supragenomic analyses among the pathogens Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae Using a modification of the finite supragenome model

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Yu Susan

2011-04-01

Full Text Available Abstract Background Staphylococcus aureus is associated with a spectrum of symbiotic relationships with its human host from carriage to sepsis and is frequently associated with nosocomial and community-acquired infections, thus the differential gene content among strains is of interest. Results We sequenced three clinical strains and combined these data with 13 publically available human isolates and one bovine strain for comparative genomic analyses. All genomes were annotated using RAST, and then their gene similarities and differences were delineated. Gene clustering yielded 3,155 orthologous gene clusters, of which 2,266 were core, 755 were distributed, and 134 were unique. Individual genomes contained between 2,524 and 2,648 genes. Gene-content comparisons among all possible S. aureus strain pairs (n = 136 revealed a mean difference of 296 genes and a maximum difference of 476 genes. We developed a revised version of our finite supragenome model to estimate the size of the S. aureus supragenome (3,221 genes, with 2,245 core genes, and compared it with those of Haemophilus influenzae and Streptococcus pneumoniae. There was excellent agreement between RAST's annotations and our CDS clustering procedure providing for high fidelity metabolomic subsystem analyses to extend our comparative genomic characterization of these strains. Conclusions Using a multi-species comparative supragenomic analysis enabled by an improved version of our finite supragenome model we provide data and an interpretation explaining the relatively larger core genome of S. aureus compared to other opportunistic nasopharyngeal pathogens. In addition, we provide independent validation for the efficiency and effectiveness of our orthologous gene clustering algorithm.

Prophage induction in Haemophilus influenzae and its relationship to mutation by chemical and physical agents

International Nuclear Information System (INIS)

Balganesh, M.; Setlow, J.K.

1984-01-01

It is known that UV, X-rays, MMC and MMS are not mutagenic for H. influenzae, whereas HZ, EMS and MNNG are potent mutagens for this bacterium. All of these agents, however, are known to be both mutagenic and able to induce prophage in E. coli. We report here that all the agents except HZ induce prophage in H. influenzae, and EMS even induces in the recombination-defective recl mutant, which is non-inducible by UV, MMC, MNNG and MMS. MMS did not cause single-strand breaks or gaps in DNA synthesized after treatment of H. influenzae, but EMS and MNNG produced them. EMS caused more breaks in DNA synthesized before treatment than in that synthesized after treatment. On the other hand we did observe such breaks or gaps induced in E. coli in DNA synthesized posttreatment by EMS as well as by MMS and MNNG, at comparable survival levels. (orig.)

Prophage induction in Haemophilus influenzae and its relationship to mutation by chemical and physical agents

Energy Technology Data Exchange (ETDEWEB)

Balganesh, M.; Setlow, J.K. (Brookhaven National Lab., Upton, NY (USA))

1984-01-01

It is known that UV, X-rays, MMC and MMS are not mutagenic for H. influenzae, whereas HZ, EMS and MNNG are potent mutagens for this bacterium. All of these agents, however, are known to be both mutagenic and able to induce prophage in E. coli. We report here that all the agents except HZ induce prophage in H. influenzae, and EMS even induces in the recombination-defective recl mutant, which is non-inducible by UV, MMC, MNNG and MMS. MMS did not cause single-strand breaks or gaps in DNA synthesized after treatment of H. influenzae, but EMS and MNNG produced them. EMS caused more breaks in DNA synthesized before treatment than in that synthesized after treatment. On the other hand we did observe such breaks or gaps induced in E. coli in DNA synthesized posttreatment by EMS as well as by MMS and MNNG, at comparable survival levels.

Avaliação do impacto do programa de vacinação contra o Haemophilus influenzae tipo b (Hib) no Estado de São Paulo e município de São Paulo, após dez anos de introdução da vacina

OpenAIRE

Telma Regina Marques Pinto Carvalhanas

2014-01-01

Objetivos: Avaliar o impacto global, direto, indireto e a tendência da duração de proteção da vacinação contra o Haemophilus influenzae tipo b (Hib), no estado de São Paulo (ESP) e no município de São Paulo (MSP), na população de 0 - 59 meses, comparando os períodos pré-vacinal (1996 - 1998) e pós-vacinal (2001 - 2009). Métodos: estudo com componente descritivo e de cunho analítico, retrospectivo. A população de estudo incluiu os menores de cinco anos residentes no ESP e no MSP. Adotou-se com...

[Antibacterial activity of cefpodoxime against clinical isolates in 2000 and 2001].

Science.gov (United States)

Abe, Tomomi; Fukuoka, Takashi; Sato, Yuki; Ito, Kazuyoshi; Sei, Masami

2002-12-01

As the post-marketing surveillance of cefpodoxime proxetil (Banan), MICs of cefpodoxime (CPDX, an active form of Banan) against 1090 clinical isolates of 22 species from 15 medical institutions all over Japan from June 2000 to March 2001 were measured using the broth microdilution method approved by the Japanese Society of Chemotherapy and compared with those of oral cephem antibacterials, cefaclor, cefdinir, cefditoren, and cefcapene. In this study, remarkable change in the activity of CPDX was observed in Streptococcus pneumoniae and Haemophilus influenzae compared with the susceptibility in the studies before Banan was launched. This cause is considered to be the increase in the incidence of the following resistant strains: penicillin-intermediate S. pneumoniae (47.3%), penicillin-resistant S. pneumoniae (PRSP, 15.1%), and beta-lactamase-negative ampicillin-resistant (BLNAR) H. influenzae (24.0%), which were scarcely isolated in 1989 when Banan was launched. Other tested drugs also exhibited low activity against these resistant strains. However, CPDX showed comparatively good activity with MIC90 of 2 micrograms/mL against PRSP. Against methicillin-susceptible Staphylococcus spp., Streptococcus pyogenes, Streptococcus agalactiae, and Moraxella catarrhalis, CPDX also showed comparatively good activity with MIC90 of marketing. Against quinolones-resistant Neisseria gonorrhoeae, CPDX showed excellent activity with MIC90 of 0.5 microgram/mL. Against members of the family Enterobacteriaceae except for Citrobacter freundii, Enterobacter spp., Proteus vulgaris, and Morganella morganii, CPDX showed good activity. However, in Escherichia coli, Klebsiella spp. Proteus spp., and Providencia spp., there are some high-resistant strains to all tested drugs including CPDX. Against Peptostreptococcus spp., MIC90 of CPDX was 8 micrograms/mL and its MIC range was widely distributed from 0.03 to 32 micrograms/mL, which were similar to those in the studies before its marketing. In

Hydrolysis of N-succinyl-L,L-diaminopimelic acid by the Haemophilus influenzae dapE-encoded desuccinylase: metal activation, solvent isotope effects, and kinetic mechanism.

Science.gov (United States)

Born, T L; Zheng, R; Blanchard, J S

1998-07-21

Hydrolysis of N-succinyl-L,L-diaminopimelic acid by the dapE-encoded desuccinylase is required for the bacterial synthesis of lysine and meso-diaminopimelic acid. We have investigated the catalytic mechanism of the recombinant enzyme from Haemophilus influenzae. The desuccinylase was overexpressed in Escherichia coli and purified to homogeneity. Steady-state kinetic experiments verified that the enzyme is metal-dependent, with a Km for N-succinyl-L,L-diaminopimelic acid of 1.3 mM and a turnover number of 200 s-1 in the presence of zinc. The maximal velocity was independent of pH above 7 but decreased with a slope of 1 below pH 7. The pH dependence of V/K was bell-shaped with apparent pKs of 6.5 and 8.3. Both L,L- and D,L-diaminopimelic acid were competitive inhibitors of the substrate, but d,d-diaminopimelic acid was not. Solvent kinetic isotope effect studies yielded inverse isotope effects, with values for D2OV/K of 0.62 and D2OV of 0.78. Determination of metal stoichiometry by ICP-AES indicated one tightly bound metal ion, while sequence homologies suggest the presence of two metal binding sites. On the basis of these observations, we propose a chemical mechanism for this metalloenzyme, which has a number of important structurally defined homologues.

Immunogenicity, reactogenicity and consistency of production of a Brazilian combined vaccine against diphtheria, tetanus, pertussis and Haemophilus influenzae type b

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Reinaldo de Menezes Martins

2008-11-01

Full Text Available A randomized, double-blinded study evaluating the immunogenicity, safety and consistency of production of a combined diphtheria-tetanus-pertussis-Haemophilus influenzae type b vaccine entirely produced in Brazil by Bio-Manguinhos and Instituto Butantan (DTP/Hib-BM was undertaken. The reference vaccine had the same DTP vaccine but the Hib component was produced using purified materials supplied by GlaxoSmithKline (DTP/Hib-GSK, which is registered and has supplied the Brazilian National Immunization Program for over more than five years. One thousand infants were recruited for the study and received vaccinations at two, four and six months of age. With respect to immunogenicity, the vaccination protocol was followed in 95.6% and 98.4% of infants in the DTP/Hib-BM and DTP/Hib-GSK groups, respectively. For the Hib component of the study, there was 100% seroprotection (>0.15 µg/mL with all three lots of DTP/Hib-BM and DTP/Hib-GSK. The geometric mean titer (GMT was 9.3 µg/mL, 10.3 µg/mL and 10.3 µg/mL for lots 1, 2 and 3 of DTP/Hib-BM, respectively, and the GMT was 11.3 g/mL for DTP/Hib-GSK. For diphtheria, tetanus and pertussis, seroprotection was 99.7%, 100% and 99.9%, respectively, for DTP/Hib-BM, three lots altogether and 99.2%, 100% and 100% for DTP/Hib-GSK. GMTs were similar across all lots and vaccines. Adverse events rates were comparable among the vaccine groups. The Brazilian DTP/Hib vaccine demonstrated an immunogenicity and reactogenicity profile similar to that of the reference vaccine.

Relación costo-efectividad de la vacuna contra Haemophilus influenzae tipo b en niños menores de dos años de edad en Colombia The cost-effectiveness of Haemophilus influenzae type b vaccine for children under 2 years of age in Colombia

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Nelson Alvis Guzmán

2006-10-01

Full Text Available OBJETIVOS: Las vacunas conjugadas contra Haemophilus influenzae tipo b (Hib son la herramienta más importante para prevenir la mayoría de las enfermedades invasoras producidas por dicho patógeno, pero debido a su costo, aún no se han introducido mundialmente de manera masiva. En el presente estudio se determinó la relación costo-efectividad de una vacuna contra Hib para prevenir la neumonía y la meningitis bacterianas en niños menores de 2 años en Colombia. MÉTODOS: Se estimaron los costos directos e indirectos de la neumonía y la meningitis hospitalaria y siguiendo las recomendaciones de la Organización Mundial de la Salud (OMS, la relación costo-efectividad de los programas de vacunación contra Hib. Se estimaron también las razones de costos por caso evitado de enfermedad invasora por Hib y el costo por año de vida salvado en dos situaciones hipotéticas: con vacunación contra Hib (cobertura vacunal: 90% y sin vacunación. RESULTADOS: El costo medio del tratamiento hospitalario de un caso de neumonía fue de 611,5 dólares estadounidenses (US$ (intervalo de confianza del 95% [IC95%]: 532,2 - 690,8, el costo medio del tratamiento hospitalario de un caso de meningitis fue de US$ 848,9 (IC95%: 716,8 - 981,0 y el costo por caso evitado de enfermedad invasora por Hib, de US$ 316,7 (IC95%: 294,2 - 339,2. La relación costo-efectividad en la hipótesis con vacunación fue de 2,38, frente a 3,81 en la hipótesis sin vacunación. CONCLUSIÓN: La aplicación de un programa adecuado de vacunación contra Hib en Colombia puede prevenir cerca de 25 000 casos de enfermedad invasora por año, lo que representa un ahorro de por lo menos US$ 15 millones anuales. Además, puede evitar cerca de 700 defunciones y salvar anualmente 44 054 años de vida.OBJECTIVE: Conjugate vaccines are the best public health tools available for preventing most invasive diseases caused by Haemophilus influenzae type b (Hib, but the high cost of the vaccines has so

Sensibilidade a antimicrobianos de bactérias isoladas do trato respiratório de pacientes com infecções respiratórias adquiridas na comunidade: resultados brasileiros do Programa SENTRY de Vigilância de Resistência a Antimicrobianos dos anos de 1997 e 1998 Susceptibility to respiratory tract isolated bacteria to antimicrobial agents in patients with community-acquired respiratory tract infections: 1997 and 1998 Brazilian data of the SENTRY surveillance program of resistance to antimicrobial agents

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HÉLIO S. SADER

2001-01-01

Full Text Available O tratamento da pneumonia adquirida na comunidade (PAC é habitualmente empírico e o uso de antimicrobianos é baseado em estudos de vigilância. O programa SENTRY foi desenhado para monitorar a resistência a antimicrobianos através de uma rede internacional de laboratórios. Três centros no Brasil participaram do Programa SENTRY em 1997 e em 1998. Métodos: Um total de 344 isolados bacterianos coletados de pacientes com PAC em 1997 e 1998 foram testados contra mais de 20 agentes antimicrobianos pelo método de microdiluição em caldo. Resultados: Entre os S. pneumoniae (176 isolados, 71,6% foram sensíveis à penicilina. Alto nível de resistência à penicilina e resistência à cefotaxima foram encontrados em 2,3 e 4,0%, respectivamente. As novas quinolonas levofloxacina (MIC90, 2mig/mL e gatifloxacina (MIC90, 0,5mig/mL foram ativas contra 100% dos isolados testados. Entre os outros antimicrobianos não beta-lactâmicos testados, os mais ativos foram (% de sensibilidade: cloranfenicol (97,5% > clindamicina (94% > azitromicina (90,3% > claritromicina (89,4% > tetraciclina (76,4% > sulfametoxazol/trimetoprim (60,2%. A percentagem de Haemophilus influenzae (101 isolados resistentes à amoxicilina foi de 90,1%, enquanto entre Moraxella catarrhalis (67 isolados somente 9,0% foram sensíveis. O ácido clavulânico restaurou a atividade de amoxicilina contra H. influenzae e M. catarrhalis. Porém, H. influenzae demonstrou níveis aumentados de resistência para sulfametoxazol/trimetoprim (55,1% de sensibilidade, claritromicina (80,4% de sensibilidade e cefaclor (88,2% de sensibilidade. Todos os isolados de H. influenzae e M. catarrhalis foram sensíveis à levofloxacina (MIC90, Background: Antimicrobial treatment of community-acquired respiratory tract infections (CARTI is usually empiric and antibiotics are chosen on the basis of surveillance studies. The SENTRY Program was designed to monitor antimicrobial resistance via a worldwide

21 CFR 866.3300 - Haemophilus spp. serological reagents.

Science.gov (United States)

2010-04-01

... serological tests to identify Haemophilus spp. directly from clinical specimens or tissue culture isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by bacteria belonging to the genus Haemophilus and provides epidemiological information on diseases cause by these...

Antibiotikavalg ved purulent meningitis uden bakteriologisk diagnose

DEFF Research Database (Denmark)

Krarup, H B

1989-01-01

A case of meningitis in a 16 month old boy caused by Hemophilus influenzae resistant to ampicillin is presented. The question is raised whether a third generation cephalosporin such as cefotaxime should be the drug of choice in the treatment of bacterial meningitis with unknown etiology...

Author Details

African Journals Online (AJOL)

Safety and immunogenicity of TetractHib (a vaccine combining DTP vaccine and Haemophilus influenza type b conjugate vaccine) administered to infants at 6, 10 and 14 weeks of age. Abstract PDF · Vol 106, No 9 (2016) - Articles Invasive carbapenem-resistant Enterobacteriaceae infection at a paediatric hospital: A case ...

The Viriato Study: Update of antimicrobial susceptibility data of bacterial pathogens from community-acquired respiratory tract infections in Portugal in 2003 and 2004

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J. Melo-Cristino

2006-01-01

Full Text Available The Viriato Study is a nationwide, prospective, multicenter surveillance study of the antimicrobial susceptibility of bacterial pathogens commonly associated with community-acquired respiratory tract infections in Portugal. In 2003 and 2004 a total of 2945 isolates was recovered in the 29 laboratories that participated in the study. Testing was undertaken in a central laboratory. Of the 513 Streptococcus pyogenes strains isolated from patients with acute tonsillitis all were susceptible to penicillin and other beta-lactams but 18.9% were resistant to erythromycin, clarithromycin and azithromycin. The M phenotype dominated (67%, conferring resistance to erythromycin (MIC90 = 16 mg/L, clarythromycin and azithromycin, but susceptibility to clindamycin (MIC90 = 0.094 mg/L. From patients with lower respiratory tract infection 1,300 strains of Streptococcus pneumoniae, 829 of Haemophilus influenzae, and 303 of Moraxella catarrhalis were studied. Among S. pneumoniae isolates 18.4% were resistant to penicillin (3.5% showing high-level resistance, 7.1% to cefuroxime, 0.5% to amoxicillin and amoxicillin/clavulanate, 18.8% to erythromycin, clarithromycin and azithromycin, 14.9% to tetracycline, 16.5% to co-trimoxazol, and 0.4% to levofloxacin. Beta-lactamases were produced by 10.0% of H. influenzae and 96.4% of M. catarrhalis. In H. influenzae resistance to clarithromycin was 5.5% and to cotrimoxazole was 13.4%. Most strains were susceptible to amoxicillin/clavulanate, cefuroxime, azithromycin, tetracycline and ciprofloxacin. In M. catarrhalis resistance to co-trimoxazole was 27.1% and to tetracycline 1.0%. All strains were susceptible to amoxicillin/clavulanate, cefuroxime, clarithromycin, azithromycin and ciprofloxacin. Penicillin was the most active antimicrobial agent against S. pyogenes and amoxycillin / clavulanate and the quinolones the most active in vitro simultaneously against S. pneumoniae, H. influenza and M. catarrhalis. Resumo: O Estudo

Efficacy and safety of Sultamicillin (Ampicillin/Sulbactan) and Amoxicillin/Clavulanic acid in the treatment of upper respiratory tract infections in adults--an open-label, multicentric, randomized trial.

Science.gov (United States)

Ferreira, João Batista; Rapoport, Priscila Bogar; Sakano, Eulália; Kós, Arthur Octávio De Avila; Piltcher, Otávio B; Pignatari, Shirley Shizue Nagata; Pinheiro, Sebastião Diógenes; Mocellin, Marcos

2006-01-01

Upper respiratory tract infections are the most common causes of medical visits in children and adults, demanding massive use of antibiotics. Bacterial resistance caused by beta-lactamase is one of the most serious problems in this matter. Sultamicillin, a double pro-drug of Ampicillin/Sulbactan, is a potent beta-lactamase inhibitor which can face this challenge. Evaluate efficacy, safety and tolerability of Ampicillin/Sulbactan compared to Amoxicillin/Clavulanate in upper respiratory tract infections in adults. 102 patients were enrolled and randomized to receive Ampicillin/Sulbactan or Amoxicillin/Clavulanate during 10 days. They were evaluated 10 and 30 days after treatment to learn about the therapeutic response. There were no differences between the two groups respecting cure at the end of treatment (visit 2) or at the end of the study (visit 3). Cure ratio was 61.7% and 93.2% (visits 2 and 3) in the Amoxicillin/Clavulanate group compared to 64.4% and 97.4%, respectively, in Ampicillin/Sulbactan group. The adverse events ratio for the two groups was the same (p=0.940). The number of patients with diarrhea was greater in the group of patients receiving Amoxicillin/Clavulanate (70.6%) than in the group receiving Ampicillin/Sulbactan (29.4%) (p=0.0164). Ampicillin/Sulbactan is as safe and efficient as Amoxicillin/Clavulanate in the empiric treatment of upper respiratory infections in adults. The low occurrence of diarrhea in the group receiving Ampicillin/Sulbactan needs confirmation in other studies.

Comparison of the in vitro activities of several new fluoroquinolones against respiratory pathogens and their abilities to select fluoroquinolone resistance.

Science.gov (United States)

Boswell, F J; Andrews, J M; Jevons, G; Wise, R

2002-10-01

In this study the in vitro activities and pharmacodynamic properties of moxifloxacin, levofloxacin, gatifloxacin and gemifloxacin were compared on recently isolated respiratory pathogens and strains of Streptococcus pneumoniae with known mechanisms of fluoroquinolone resistance. In addition, the resistance selection frequencies of moxifloxacin and levofloxacin on three recently isolated respiratory pathogens and four strains of S. pneumoniae with known mechanisms of fluoroquinolone resistance were investigated. The four fluoroquinolones had similar activities against both Moraxella catarrhalis (MIC(90)s 0.015-0.06 mg/L) and Haemophilus influenzae (MIC(90)s 0.008-0.03 mg/L). More marked differences in activity were noted with S. pneumoniae, with MIC(90)s of 0.25, 1, 0.5 and 0.03 mg/L for moxifloxacin, levofloxacin, gatifloxacin and gemifloxacin, respectively. With the S. pneumoniae strains, the four fluoroquinolones exhibited similar concentration-dependent time-kill kinetics. The resistance selection frequencies of levofloxacin were higher than those of moxifloxacin at concentrations equivalent to those at the end of the dosing interval. Therefore moxifloxacin may have less of an impact on the development of resistance than levofloxacin.

Impacto de la vacuna conjugada en la incidencia de meningitis por Haemophilus influenzae en el Distrito Federal de Brasil: resultados de tres años de seguimiento Impact of anti-Hib conjugate vaccine on the incidence of Haemophilus influenzae meningitis in Brazil's Federal District: results of a three-year follow-up

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Helen Selma de Abreu Freitas

2006-01-01

Full Text Available INTRODUCCIÓN: Haemophilus influenzae del serotipo b (Hib es todavía un importante agente causal de procesos infecciosos. Su variante encapsulada es la causa de formas invasoras de enfermedad. En algunas poblaciones aborígenes, la incidencia de enfermedades causadas por Hib es mayor de 400 por 100 000 niños menores de 5 años. En los decenios de 1970 y 1980, tras la identificación de anticuerpos protectores contra la cápsula de Hib, se desarrollaron vacunas contra este microorganismo. OBJETIVO: Estimar el impacto que ha tenido desde su introducción, en marzo de 1998, la vacunación contra Hib en el Distrito Federal de Brasil. MÉTODO: Con los datos de base poblacional del Sistema de Vigilancia de la Secretaría de Salud del Distrito Federal de Brasil, se compararon las tasas de incidencia de meningitis correspondientes a los tres años anteriores y posteriores a la introducción de la vacuna. Se compararon también los cambios en su tendencia. RESULTADOS: Al comparar los dos períodos se advierte una reducción de aproximadamente 90% en la incidencia de meningitis por Hib, cambio que no ocurre en el caso de las meningitis ocasionadas por otros agentes bacterianos. Se registró un aumento proporcional de los casos entre los niños de 6 meses de edad y menores, debido a la reducción de la incidencia entre los mayores de esa edad. CONCLUSIÓN: La introducción de la vacuna conjugada en el Distrito Federal de Brasil redujo de 168 por 100 000 (1995-1997 a 15 por 100 000 (1999-2001 la incidencia de meningitis por Hib entre niños de 7 a 35 meses. Esto representa una reducción de 91,1%.INTRODUCTION: Type b Haemophilus influenzae (Hib continues to be an important causative agent of various infectious processes, and its encapsulated strains cause invasive disease. In some aboriginal populations, the incidence of Hib infections in children under five is greater than 400 per 100 000. In the seventies and eighties, vaccines against Hib were

Cloning and analysis of the genes encoding the type IIS restriction-modification system HphI from Haemophilus parahaemolyticus.

Science.gov (United States)

Lubys, A; Lubienè, J; Kulakauskas, S; Stankevicius, K; Timinskas, A; Janulaitis, A

1996-07-15

The genomic region encoding the type IIS restriction-modification (R-M) system HphI (enzymes recognizing the asymmetric sequence 5'-GGTGA-3'/5'-TCACC-3') from Haemophilus parahaemolyticus were cloned into Escherichia coli and sequenced. Sequence analysis of the R-M HphI system revealed three adjacent genes aligned in the same orientation: a cytosine 5 methyltransferase (gene hphIMC), an adenine N6 methyltransferase (hphIMA) and the HphI restriction endonuclease (gene hphIR). Either methyltransferase is capable of protecting plasmid DNA in vivo against the action of the cognate restriction endonuclease. hphIMA methylation renders plasmid DNA resistant to R.Hindill at overlapping sites, suggesting that the adenine methyltransferase modifies the 3'-terminal A residue on the GGTGA strand. Strong homology was found between the N-terminal part of the m6A methyltransferasease and an unidentified reading frame interrupted by an incomplete gaIE gene of Neisseria meningitidis. The HphI R-M genes are flanked by a copy of a 56 bp direct nucleotide repeat on each side. Similar sequences have also been identified in the non-coding regions of H.influenzae Rd DNA. Possible involvement of the repeat sequences in the mobility of the HphI R-M system is discussed.

Multidrug resistance in pediatric urinary tract infections.

Science.gov (United States)

Gaspari, Romolo J; Dickson, Eric; Karlowsky, James; Doern, Gary

2006-01-01

Urinary tract infections (UTIs) represent a common infection in the pediatric population. Escherichia coli is the most common uropathogen in children, and antimicrobial resistance in this species complicates the treatment of pediatric UTIs. Despite the impact of resistance on empiric antibiotic choice, there is little data on multidrug resistance in pediatric patients. In this paper, we describe characteristics of multidrug-resistant E. coli in pediatric patients using a large national database of uropathogens antimicrobial sensitivities. Antimicrobial susceptibility patterns to commonly prescribed antibiotics were performed on uropathogens isolated from children presenting to participating hospitals between 1999 and 2001. Data were analyzed separately for four pediatric age groups. Single and multidrug resistance to ampicillin, amoxicillin-clavulanate, cefazolin, ciprofloxacin, nitrofurantoin, and trimethoprim-sulfamethoxazole (TMP-SMX) were performed on all specimens. There were a total of 11,341 E. coli urine cultures from 343 infants (0-4 weeks), 1,801 toddlers (5 weeks-24 months), 6,742 preteens (2-12 years), and 2,455 teens (13-17 years). E. coli resistance to ampicillin peaked in toddlers (52.8%) but was high in preteens (52.1%), infants (50.4%), and teens (40.6%). Resistance to two or more antibiotics varied across age groups, with toddlers (27%) leading preteens (23.1%), infants (21%), and teens (15.9%). Resistance to three or more antibiotics was low in all age groups (range 3.1-5.2%). The most common co-resistance in all age groups was ampicillin/TMP-SMZ. In conclusion, less than half of all pediatric UTIs are susceptible to all commonly used antibiotics. In some age groups, there is a significant percentage of co-resistance between the two most commonly used antibiotics (ampicillin and TMP-SMZ).

Antimicrobial susceptibility against penicillin, ampicillin and vancomycin of viridans group Streptococcus in oral microbiota of patients at risk of infective endocarditis.

Science.gov (United States)

Süzük, Serap; Kaşkatepe, Banu; Çetin, Mustafa

2016-09-01

The viridans group Streptococci (VGS) are most abundant in the mouth; in some instances they might emerge as pathogens particularly in infective endocarditis (IE). In this study, we aimed to define and determine the susceptibility against antibiotics of VGS that are members of the oral microbiota of patients exhibiting a risk of developing IE. Forty-nine patients at risk of infective endocarditis were included in the study. Identification of the bacteria was performed using API STREP (bioMérieux, France). Gradient test strips (E-Test, France) were used to determine MIC of the bacteria against penicillin, ampicillin, and vancomycin. The distribution of the isolated VGS groups was determined as follows: Streptococcus mitis 32.6% and anginosus group - 32.6%, S. sanguinis group - 16.3%, S. mutans group - 12.2%, and S. salivarius group - 6.1%. The rates of resistance and reduced sensitivity of the isolates for penicillin and ampicillin were determined at 61.2% and 55.1%, respectively. However, all isolates were found to be susceptible to vancomycin. We conclude that the antimicrobial resistance of VGS should be determined on a regular basis locally, and decisions on therapeutic and prophylactic interventions should be given taking this resistance into consideration.

Dicty_cDB: VHB466 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available nce. 50 0.006 2 DD419614 |DD419614.1 GENES OF AN OTITIS MEDIA ISOLATE OF NONTYPEABLE HAEMOPHILUS INFLUENZAE.... 54 0.006 1 DD419394 |DD419394.1 GENES OF AN OTITIS MEDIA ISOLATE OF NONTYPEABLE HAEMOPHILUS INFLUENZAE. 54

Evaluation of fever in infants and young children.

Science.gov (United States)

Hamilton, Jennifer L; John, Sony P

2013-02-15

Febrile illness in children younger than 36 months is common and has potentially serious consequences. With the widespread use of immunizations against Streptococcus pneumoniae and Haemophilus influenzae type b, the epidemiology of bacterial infections causing fever has changed. Although an extensive diagnostic evaluation is still recommended for neonates, lumbar puncture and chest radiography are no longer recommended for older children with fever but no other indications. With an increase in the incidence of urinary tract infections in children, urine testing is important in those with unexplained fever. Signs of a serious bacterial infection include cyanosis, poor peripheral circulation, petechial rash, and inconsolability. Parental and physician concern have also been validated as indications of serious illness. Rapid testing for influenza and other viruses may help reduce the need for more invasive studies. Hospitalization and antibiotics are encouraged for infants and young children who are thought to have a serious bacterial infection. Suggested empiric antibiotics include ampicillin and gentamicin for neonates; ceftriaxone and cefotaxime for young infants; and cefixime, amoxicillin, or azithromycin for older infants.

Meningitis and pneumonia in Guatemalan children: the importance of Haemophilus influenzae type b and Streptococcus pneumoniae Meningitis y neumonía en niños guatemaltecos: importancia de Haemophilus influenzae tipo b y de Streptococcus pneumoniae

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Edwin J. Asturias

2003-12-01

Full Text Available OBJECTIVE: To determine the epidemiology of Haemophilus influenzae type b (Hib and Streptococcus pneumoniae invasive infections in hospitalized Guatemalan children. This is an important issue since Hib vaccine has not been incorporated into the routine immunization program in Guatemala and information from hospital records in 1995 indicated a low incidence of Hib and S. pneumoniae as causes of meningitis and invasive infections. METHODS: Children who were hospitalized in Guatemala City with clinical signs compatible with bacterial infections were evaluated for evidence of Hib or S. pneumoniae infection. Normally sterile body fluids were cultured, and antigen detection was performed on cerebrospinal fluid (CSF and pleural fluid. RESULTS: Of 1 203 children 1-59 months of age hospitalized over a 28-month period, 725 of them (60.3% had a primary diagnosis of pneumonia, 357 (29.7% of meningitis, 60 (5.0% of cellulitis, and 61 (5.1% of sepsis and other conditions. Hib was identified in 20.0% of children with meningitis and S. pneumoniae in 12.9%. The average annual incidence of Hib meningitis was 13.8 cases per 100 000 children under 5 years of age, and 32.4% of meningitides caused by Hib and 58.7% of S. pneumoniae meningitides occurred prior to 6 months of age. Case fatality rates were 14.1%, 37.0%, and 18.0%, respectively, for children with Hib, S. pneumoniae, and culture-negative and antigen-negative meningitis. Prior antibiotic therapy was common and was associated with significant reductions in CSF-culture-positive results for children with other evidence of Hib or S. pneumoniae meningitis. CONCLUSIONS: Improvements in case detection, culture methods, and latex agglutination for antigen detection in CSF resulted in identification of Hib and S. pneumoniae as important causes of severe disease in Guatemalan children. Using a cutoff of > 10 white blood cells per cubic millimeter in CSF would improve the sensitivity for detection of bacterial

The effect of PDT on H. influenzae biofilm in vivo

Science.gov (United States)

Rhee, Chung-Ku; Chang, So-Young; Hwang, Dong-Jo; Kim, Young Hoon; Ahn, Jin-Chul

2010-02-01

Biofilm formation has been demonstrated for many mucosal pathogens such as Haemophilus influenzae. The presence of mucosal biofilms with chronic otitis media with effusion (COME) suggests that bacteria do not clear by antibiotics. Aim: To test the effect of photodynamic therapy (PDT) on H. influenzae induced biofilm in vivo. Methods: Gerbils were divided into control (C), HI group, Laser (L), PS, PDT A, and PDT B groups. The C group received no treatment. HI group was injected with 20μl (108CFU/ml) of H. influenzae into the bullae and formation of biofilms in the bullae was obtained by 5 days. For L group, 120 J/cm2 (100 mw × 20 min) of 632 nm LD laser was irradiated by a fiber inserted into the bullae 5 days after the H. influenzaeinjection. For PS group, photofrin 40μl (1mg/ml) were injected into the bullae 5 days after the H. influenzae injection. PDT A group received photofrin 1 mg/ml and LD laser 120 J/cm2 that were administered into the bullae 5 days after the H. influenzae injection. PDT B group received photofrin 2 mg/ml and laser 150 J/cm2 5 days after the H. influenzae injection. The mucosal tissues in bullae were examined by H/E staining, and SEM. Results: The C group showed normal mucosa of bullae. The HI, L, and PS groups have shown well formed biofilm. Twenty five percent of the PDT A group and 50 % of the PDT B group have shown completely or partially resolved biofilm. Conclusion: The results of this study demonstrated that PDT appears to be effective to treat experimental H. influenzae induced biofilms in vivo. Clinical implication: PDT may be an alternative to antibiotic treatment on otitis media with biofilm formation.

Longitudinal nasopharyngeal carriage and antibiotic resistance of respiratory bacteria in indigenous Australian and Alaska native children with bronchiectasis.

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Kim M Hare

Full Text Available BACKGROUND: Indigenous children in Australia and Alaska have very high rates of chronic suppurative lung disease (CSLD/bronchiectasis. Antibiotics, including frequent or long-term azithromycin in Australia and short-term beta-lactam therapy in both countries, are often prescribed to treat these patients. In the Bronchiectasis Observational Study we examined over several years the nasopharyngeal carriage and antibiotic resistance of respiratory bacteria in these two PCV7-vaccinated populations. METHODS: Indigenous children aged 0.5-8.9 years with CSLD/bronchiectasis from remote Australia (n = 79 and Alaska (n = 41 were enrolled in a prospective cohort study during 2004-8. At scheduled study visits until 2010 antibiotic use in the preceding 2-weeks was recorded and nasopharyngeal swabs collected for culture and antimicrobial susceptibility testing. Analysis of respiratory bacterial carriage and antibiotic resistance was by baseline and final swabs, and total swabs by year. RESULTS: Streptococcus pneumoniae carriage changed little over time. In contrast, carriage of Haemophilus influenzae declined and Staphylococcus aureus increased (from 0% in 2005-6 to 23% in 2010 in Alaskan children; these changes were associated with increasing age. Moraxella catarrhalis carriage declined significantly in Australian, but not Alaskan, children (from 64% in 2004-6 to 11% in 2010. While beta-lactam antibiotic use was similar in the two cohorts, Australian children received more azithromycin. Macrolide resistance was significantly higher in Australian compared to Alaskan children, while H. influenzae beta-lactam resistance was higher in Alaskan children. Azithromycin use coincided significantly with reduced carriage of S. pneumoniae, H. influenzae and M. catarrhalis, but increased carriage of S. aureus and macrolide-resistant strains of S. pneumoniae and S. aureus (proportion of carriers and all swabs, in a 'cumulative dose-response' relationship

Depletion of long-acting ampicillin in goat milk following intramuscular administration.

Science.gov (United States)

Ferrini, Anna Maria; Trenta, Simona; Mannoni, Veruscka; Rosati, Remo; Coni, Ettore

2010-12-08

Although goat milk production represents today a very small percentage of the world milk market, this percentage has been growing continuously during the past 20 years. Goat milk is the basic milk supply in many developing countries and provides tasteful derivative products in developed countries. Goats, as well as all milk-producing animals, can be affected by mastitis, but goats being considered a minor species, few drugs are specifically registered for these animals; most, at least for mastitis treatment, are usually tested and registered for use in cows. This situation leads often to the adoption for goat milk of withdrawal periods defined for cows even if these extrapolations prove almost never valid for goats. In the present study, the elimination of the β-lactam antibacterial agent ampicillin in goat milk was investigated. Ampicillin was chosen because it is one of the most common antibiotics used by goat farmers against mastitis due to the fact that it is well tolerated and has short elimination times in cows. Goats were treated with long-acting ampicillin at 15 mg (kg of body weight)(-1) by double intramuscular injection at 72 h interval. Milk was collected in a 12 h milking scheme. The method used to determine the levels of ampicillin in goat milk was based on a liquid-liquid extraction of this drug from the matrix, successive derivatization with formaldehyde, and final separation by HPLC with fluorescence detection. The results point out a slow depletion of ampicillin and, consequently, a withdrawal period (13 milkings) longer than that extrapolated and authorized for cows and sheep.

The effects of tertiary wastewater treatment on the prevalence of antimicrobial resistant bacteria

DEFF Research Database (Denmark)

Guardabassi, L.; Wong, Danilo Lo Fo; Dalsgaard, A.

2002-01-01

and anaerobically digested sludge by bacteriological counts on media selective for coliforms (MacConkey agar) and Acinetobacter spp. (Baumann agar). In addition, the level of antimicrobial susceptibility was determined by the disc-diffusion method in 442 Acinetobacter isolates identified by colony hybridisation......-resistant presumptive coliforms and Acinetobacter spp. in treated sewage and digested sludge were not significantly higher compared with raw sewage. On the contrary at one plant, statistically significant decreases were observed in the prevalence of ampicillin-resistant presumptive Acinetobacter spp. (p = 0.......0188) following sewage treatment, and in the prevalence of either ampicillin-resistant presumptive Acinetobacter spp. (p = 0.0013) or ampicillin- and gentamicin-resistant presumptive coliforms (p = 0.0273 and p = 0.0186) following sludge treatment. The results obtained by bacteriological counts were confirmed...

Outbreak of Ampicillin/Piperacillin-Resistant Klebsiella Pneumoniae in a Neonatal Intensive Care Unit (NICU: Investigation and Control Measures

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Patrizia Farruggia

2013-02-01

Full Text Available Klebsiella pneumoniae is a frequent cause of infectious outbreaks in Neonatal Intensive Care Units (NICUs. The aim of this paper is to describe an outbreak occurred in a 13-bed NICU and the control measures adopted in order to interrupt the chain of transmission. We described the microbiological investigations, the NICU staff compliance to the infection control measures by means of a specifically designed check-list and the control measures adopted. Six cases of primary bloodstream infections sustained by ampicillin/piperacillin-resistant Klebsiella pneumoniae were observed over a two-month period. One culture obtained from a 12% saccarose multiple-dose solution allowed the growth of Klebsiella pneumoniae. During the inspections performed by the Hospital Infection Control Team, using the check-list for the evaluation of the NICU staff compliance to the infection control measures, several breaches in the infection control policy were identified and control measures were adopted. In our case the definition of a specific check-list led to the adoption of the correct control measures. Further studies would be helpful in order to develop a standard check-list able to identify critical flows in the adhesion to the guidelines. It could be used in different NICUs and allow to obtain reproducible levels of infection control.

Outbreak of ampicillin/piperacillin-resistant Klebsiella pneumoniae in a neonatal intensive care unit (NICU): investigation and control measures.

Science.gov (United States)

Fabbri, Giuliana; Panico, Manuela; Dallolio, Laura; Suzzi, Roberta; Ciccia, Matilde; Sandri, Fabrizio; Farruggia, Patrizia

2013-02-26

Klebsiella pneumoniae is a frequent cause of infectious outbreaks in Neonatal Intensive Care Units (NICUs). The aim of this paper is to describe an outbreak occurred in a 13-bed NICU and the control measures adopted in order to interrupt the chain of transmission. We described the microbiological investigations, the NICU staff compliance to the infection control measures by means of a specifically designed check-list and the control measures adopted. Six cases of primary bloodstream infections sustained by ampicillin/piperacillin-resistant Klebsiella pneumoniae were observed over a two-month period. One culture obtained from a 12% saccarose multiple-dose solution allowed the growth of Klebsiella pneumoniae. During the inspections performed by the Hospital Infection Control Team, using the check-list for the evaluation of the NICU staff compliance to the infection control measures, several breaches in the infection control policy were identified and control measures were adopted. In our case the definition of a specific check-list led to the adoption of the correct control measures. Further studies would be helpful in order to develop a standard check-list able to identify critical flows in the adhesion to the guidelines. It could be used in different NICUs and allow to obtain reproducible levels of infection control.

Rapid determination of ampicillin in bovine milk by liquid chromatography with fluorescence detection

Energy Technology Data Exchange (ETDEWEB)

Ang, C.Y.W.; Luo, Wenhong [National Center for Toxicological Research, Jefferson, AR (United States)

1997-01-01

A rapid and sensitive liquid chromatographic (LC) method was developed for the determination of ampicillin residues in raw bovine milk, processed skim milk, and pasteurized, homogenized whole milk with vitamin D. Milk samples were deproteinized with trichloroacetic acid (TCA) and acetonictrile. After centrifugation, the clear supernatant was reacted with formaldehyde and TCA under heat. The major fluorescent derivative of ampicillin was then determined by reversed-phase LC with fluorescence detection. Average recoveries of ampicillin fortified at 5, 10, and 20 ppb (ng/mL) were all >85% with coefficients of variation <10%. Limits of detection ranged from 0.31 to 0.51 ppb and limits of quantitation, from 0.66 to 1.2 ppb. After appropriate validation, this method should be suitable for rapid analysis of milk for ampicillin residues at the tolerance level of 10 ppb. 16 refs., 4 figs., 3 tabs.

The Kinetics of Ampicillin Release from Hydroxyapatite for Bones Regeneration

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Giovanilton Ferreira da Silva

2009-01-01

Full Text Available Semisynthetic beta-lactam antibiotics are among the most used pharmaceuticals. Their use in veterinary and human medicine is in continuous expansion. There is a growing need for developing bioactive implants. Advantages of implantable drug delivery tools can include high release efficiency, precise dose control, low toxicity, and allow to overcome disadvantages connected with conventional methods. In this respect, hydroxyapatite (HA is an elective material. It enables to produce architectures similar to those of real bones. Here we studied a kinetic model to describe ampicillin release from HA. In the course of adsorption experiment, ampicillin was dissolved, maintained at 30∘C and shaken at 60 strokes/minute. Samples were withdrawn periodically for analysis and then returned to the mixture. Adsorbed amounts were measured by the difference of the concentration of the antibiotics before and after adsorption using UV adsorption at 225 nm. The aim of this work was to evaluate its application as ampicillin delivery carrier.

IgG responses to Pneumococcal and Haemophilus influenzae protein antigens are not impaired in children with a history of recurrent acute otitis media.

Science.gov (United States)

Wiertsema, Selma P; Corscadden, Karli J; Mowe, Eva N; Zhang, Guicheng; Vijayasekaran, Shyan; Coates, Harvey L; Mitchell, Timothy J; Thomas, Wayne R; Richmond, Peter C; Kirkham, Lea-Ann S

2012-01-01

Vaccines including conserved antigens from Streptococcus pneumoniae and nontypeable Haemophilus influenzae (NTHi) have the potential to reduce the burden of acute otitis media. Little is known about the antibody response to such antigens in young children with recurrent acute otitis media, however, it has been suggested antibody production may be impaired in these children. We measured serum IgG levels against 4 pneumococcal (PspA1, PspA 2, CbpA and Ply) and 3 NTHi (P4, P6 and PD) proteins in a cross-sectional study of 172 children under 3 years of age with a history of recurrent acute otitis media (median 7 episodes, requiring ventilation tube insertion) and 63 healthy age-matched controls, using a newly developed multiplex bead assay. Children with a history of recurrent acute otitis media had significantly higher geometric mean serum IgG levels against NTHi proteins P4, P6 and PD compared with healthy controls, whereas there was no difference in antibody levels against pneumococcal protein antigens. In both children with and without a history of acute otitis media, antibody levels increased with age and were significantly higher in children colonised with S. pneumoniae or NTHi compared with children that were not colonised. Proteins from S. pneumoniae and NTHi induce serum IgG in children with a history of acute otitis media. The mechanisms in which proteins induce immunity and potential protection requires further investigation but the dogma of impaired antibody responses in children with recurrent acute otitis media should be reconsidered.

IgG responses to Pneumococcal and Haemophilus influenzae protein antigens are not impaired in children with a history of recurrent acute otitis media.

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Selma P Wiertsema

Full Text Available BACKGROUND: Vaccines including conserved antigens from Streptococcus pneumoniae and nontypeable Haemophilus influenzae (NTHi have the potential to reduce the burden of acute otitis media. Little is known about the antibody response to such antigens in young children with recurrent acute otitis media, however, it has been suggested antibody production may be impaired in these children. METHODS: We measured serum IgG levels against 4 pneumococcal (PspA1, PspA 2, CbpA and Ply and 3 NTHi (P4, P6 and PD proteins in a cross-sectional study of 172 children under 3 years of age with a history of recurrent acute otitis media (median 7 episodes, requiring ventilation tube insertion and 63 healthy age-matched controls, using a newly developed multiplex bead assay. RESULTS: Children with a history of recurrent acute otitis media had significantly higher geometric mean serum IgG levels against NTHi proteins P4, P6 and PD compared with healthy controls, whereas there was no difference in antibody levels against pneumococcal protein antigens. In both children with and without a history of acute otitis media, antibody levels increased with age and were significantly higher in children colonised with S. pneumoniae or NTHi compared with children that were not colonised. CONCLUSIONS: Proteins from S. pneumoniae and NTHi induce serum IgG in children with a history of acute otitis media. The mechanisms in which proteins induce immunity and potential protection requires further investigation but the dogma of impaired antibody responses in children with recurrent acute otitis media should be reconsidered.

Ampicillin potentials as Corrosion Inhibitor: fukui function ...

African Journals Online (AJOL)

The experimental study was carried out using gravimetric and Fourier transform infrared spectroscopy methods of monitoring corrosion while the computational study was carried out using quantum chemical approach via Hyperchem program suit. The results obtained showed that various concentrations of ampicillin ...

Hedging against antiviral resistance during the next influenza pandemic using small stockpiles of an alternative chemotherapy.

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Joseph T Wu

2009-05-01

Full Text Available The effectiveness of single-drug antiviral interventions to reduce morbidity and mortality during the next influenza pandemic will be substantially weakened if transmissible strains emerge which are resistant to the stockpiled antiviral drugs. We developed a mathematical model to test the hypothesis that a small stockpile of a secondary antiviral drug could be used to mitigate the adverse consequences of the emergence of resistant strains.We used a multistrain stochastic transmission model of influenza to show that the spread of antiviral resistance can be significantly reduced by deploying a small stockpile (1% population coverage of a secondary drug during the early phase of local epidemics. We considered two strategies for the use of the secondary stockpile: early combination chemotherapy (ECC; individuals are treated with both drugs in combination while both are available; and sequential multidrug chemotherapy (SMC; individuals are treated only with the secondary drug until it is exhausted, then treated with the primary drug. We investigated all potentially important regions of unknown parameter space and found that both ECC and SMC reduced the cumulative attack rate (AR and the resistant attack rate (RAR unless the probability of emergence of resistance to the primary drug p(A was so low (less than 1 in 10,000 that resistance was unlikely to be a problem or so high (more than 1 in 20 that resistance emerged as soon as primary drug monotherapy began. For example, when the basic reproductive number was 1.8 and 40% of symptomatic individuals were treated with antivirals, AR and RAR were 67% and 38% under monotherapy if p(A = 0.01. If the probability of resistance emergence for the secondary drug was also 0.01, then SMC reduced AR and RAR to 57% and 2%. The effectiveness of ECC was similar if combination chemotherapy reduced the probabilities of resistance emergence by at least ten times. We extended our model using travel data between 105

Etiologia e evolução das meningites bacterianas em centro de pediatria Etiology and evolution of bacterial meningitis in a pediatric center

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Roberta M.C. Romanelli

2002-02-01

cases of meningitis, and 111 (52.9% were caused by bacteria. Actually, 52 were probable bacterial meningitis (with liquor alterations and 59 were confirmed (with culture and/or antigen tests. The main agents were: Haemophilus influenzae, Neisseria meningitidis and Streptococcus pneumoniae. The initial treatment for children aged between three months and five years consisted of ampicillin and chloramphenicol. Later, the antibiotic was changed to penicillin in cases of Neisseria meningitidis and Streptococcus pneumoniae. and to chloramphenicol in cases of Haemophilus influenzae. Extended spectrum antimicrobial agents were used on clinical or laboratory basis, but resistant microorganisms were not found in cultures.Conclusions: the epidemiology of meningitis should be continuous and should consider local data in order to guide antimicrobial therapy. The continuous monitoring of the prevalent agents in each institution and their resistance is fundamental to the selection of antimicrobial drugs, preserving the antimicrobial agents, and causing less interference with individual colonization, without contributing to the increasing resistance of the agents responsible for meningeal infections.

Process development of a New Haemophilus influenzae type b conjugate vaccine and the use of mathematical modeling to identify process optimization possibilities.

Science.gov (United States)

Hamidi, Ahd; Kreeftenberg, Hans; V D Pol, Leo; Ghimire, Saroj; V D Wielen, Luuk A M; Ottens, Marcel

2016-05-01

Vaccination is one of the most successful public health interventions being a cost-effective tool in preventing deaths among young children. The earliest vaccines were developed following empirical methods, creating vaccines by trial and error. New process development tools, for example mathematical modeling, as well as new regulatory initiatives requiring better understanding of both the product and the process are being applied to well-characterized biopharmaceuticals (for example recombinant proteins). The vaccine industry is still running behind in comparison to these industries. A production process for a new Haemophilus influenzae type b (Hib) conjugate vaccine, including related quality control (QC) tests, was developed and transferred to a number of emerging vaccine manufacturers. This contributed to a sustainable global supply of affordable Hib conjugate vaccines, as illustrated by the market launch of the first Hib vaccine based on this technology in 2007 and concomitant price reduction of Hib vaccines. This paper describes the development approach followed for this Hib conjugate vaccine as well as the mathematical modeling tool applied recently in order to indicate options for further improvements of the initial Hib process. The strategy followed during the process development of this Hib conjugate vaccine was a targeted and integrated approach based on prior knowledge and experience with similar products using multi-disciplinary expertise. Mathematical modeling was used to develop a predictive model for the initial Hib process (the 'baseline' model) as well as an 'optimized' model, by proposing a number of process changes which could lead to further reduction in price. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:568-580, 2016. © 2016 American Institute of Chemical Engineers.

Bioavailability of pivampicillin and ampicillin trihydrate administered as an oral paste in horses

NARCIS (Netherlands)

Ensink, JM; Mol, A; Vulto, AG; Tukker, JJ

1996-01-01

Pivampicillin was administered as an oral paste to five healthy adult horses, and an oral paste with ampicillin trihydrate was administered to three horses, Pivampicillin was administered to both starved and fed horses, ampicillin trihydrate was administered to fed horses only, The dose of

[THE NATIONAL NUTRIENT MEDIUM FOR DIAGNOSTIC OF PURULENT BACTERIAL MENINGITIS].

Science.gov (United States)

Podkopaev, Ya V; Domotenko, L V; Morozova, T P; Khramov, M K; Shepelin, A P

2015-05-01

The national growth mediums were developed for isolating and cultivating of main agents of purulent bacterial meningitis--haemophilus agar, chocolate agar, PBM-agar. The growing and selective characteristics of developed growth mediums are examined. The haemophilus agar ensures growth of Haemophilus influenzae. The chocolate agar, PBM-agar ensure growth of Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae. By growing characteristics, the national growth mediums match foreign analogues. Under application of growth mediums with selective additions it is possible to achieve selective isolation of main agents of purulent bacterial meningitis with inhibition of growth of microbes-associates.

The impact of residency and urbanicity on Haemophilus influenzae Type b and pneumococcal immunization in Shanghai Children: a Retrospective Cohort Study.

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Abram L Wagner

Full Text Available BACKGROUND: Haemophilus influenzae type b (Hib vaccine and pneumococcal conjugate vaccine (PCV are relatively expensive, newly introduced vaccines in China. This study evaluates the impact of residency and urbanicity on Hib vaccine and PCV coverage for children aged 2 to 7 years living in Shanghai, China, in August 2012. METHODS: In this exploratory cohort study, a sample of children aged 2 to 7 years, all of whom were eligible to have received the complete series of Hib vaccine and PCV, was obtained from the Shanghai Immunization Program Information System. Three measures of vaccination coverage for Hib vaccine and PCV were examined: dose 1 coverage, series completion, and timeliness of dose 1 vaccination. Multivariable binomial regression was used to estimate the difference in vaccination coverage between locals and the floating population. RESULTS: Dose 1 coverage was 50.9% for Hib vaccine and 11.4% for PCV for the 28,141 abstracted pediatric records. For both vaccines, dose 1 coverage was higher in locals than in the floating population. The disparity in coverage between locals and the floating population was greater in suburban areas than urban areas. Of all children who received dose 1, 79.7% completed the Hib vaccine series, and 91.3% completed the PCV series. Timely dose 1 coverage was 8.2% for Hib vaccine and 0.5% for PCV. CONCLUSION: Low vaccination coverage and extremely low levels of timely dose 1 vaccination indicate that current vaccination efforts are inadequate to reduce the burden of Hib and pneumococcal disease among Chinese children, especially infants. Government funding of the Hib vaccine and PCV through the Expanded Program on Immunization would increase uptake and could also ensure that improvement in the timeliness of administration and series completion is targeted for all demographic groups.

New treatments for influenza.

Science.gov (United States)

Barik, Sailen

2012-09-13

Influenza has a long history of causing morbidity and mortality in the human population through routine seasonal spread and global pandemics. The high mutation rate of the RNA genome of the influenza virus, combined with assortment of its multiple genomic segments, promote antigenic diversity and new subtypes, allowing the virus to evade vaccines and become resistant to antiviral drugs. There is thus a continuing need for new anti-influenza therapy using novel targets and creative strategies. In this review, we summarize prospective future therapeutic regimens based on recent molecular and genomic discoveries.

Solution NMR structure of the V27A drug resistant mutant of influenza A M2 channel

Energy Technology Data Exchange (ETDEWEB)

Pielak, Rafal M. [Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115 (United States); Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, MA 02115 (United States); Chou, James J., E-mail: chou@cmcd.hms.harvard.edu [Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115 (United States)

2010-10-08

Research highlights: {yields} This paper reports the structure of the V27A drug resistant mutant of the M2 channel of influenza A virus. {yields} High quality NMR data allowed a better-defined structure for the C-terminal region of the M2 channel. {yields} Using the structure, we propose a proton transfer pathway during M2 proton conduction. {yields} Structural comparison between the wildtype, V27A and S31N variants allowed an in-depth analysis of possible modes of drug resistance. {yields} Distinct feature of the V27A channel pore also provides an explanation for its faster rate of proton conduction. -- Abstract: The M2 protein of influenza A virus forms a proton-selective channel that is required for viral replication. It is the target of the anti-influenza drugs, amantadine and rimantadine. Widespread drug resistant mutants, however, has greatly compromised the effectiveness of these drugs. Here, we report the solution NMR structure of the highly pathogenic, drug resistant mutant V27A. The structure reveals subtle structural differences from wildtype that maybe linked to drug resistance. The V27A mutation significantly decreases hydrophobic packing between the N-terminal ends of the transmembrane helices, which explains the looser, more dynamic tetrameric assembly. The weakened channel assembly can resist drug binding either by destabilizing the rimantadine-binding pocket at Asp44, in the case of the allosteric inhibition model, or by reducing hydrophobic contacts with amantadine in the pore, in the case of the pore-blocking model. Moreover, the V27A structure shows a substantially increased channel opening at the N-terminal end, which may explain the faster proton conduction observed for this mutant. Furthermore, due to the high quality NMR data recorded for the V27A mutant, we were able to determine the structured region connecting the channel domain to the C-terminal amphipathic helices that was not determined in the wildtype structure. The new structural

Assessing the antibiotic potential of essential oils against Haemophilus ducreyi.

Science.gov (United States)

Lindeman, Zachary; Waggoner, Molly; Batdorff, Audra; Humphreys, Tricia L

2014-05-27

Haemophilus ducreyi is the bacterium responsible for the genital ulcer disease chancroid, a cofactor for the transmission of HIV, and it is resistant to many antibiotics. With the goal of exploring possible alternative treatments, we tested essential oils (EOs) for their efficacy as antimicrobial agents against H. ducreyi. We determine the minimum inhibitory concentration (MIC) of Cinnamomum verum (cinnamon), Eugenia caryophyllus (clove) and Thymus satureioides (thyme) oil against 9 strains of H. ducreyi using the agar dilution method. We also determined the minimum lethal concentration for each oil by subculturing from the MIC plates onto fresh agar without essential oil. For both tests, we used a 2-way ANOVA to evaluate whether antibiotic-resistant strains had a different sensitivity to the oils relative to non-resistant strains. All 3 oils demonstrated excellent activity against H. ducreyi, with MICs of 0.05 to 0.52 mg/mL and MLCs of 0.1-0.5 mg/mL. Antibiotic-resistant strains of H. ducreyi were equally susceptible to these 3 essential oils relative to non-resistant strains (p=0.409). E. caryophyllus, C. verum and T. satureioides oils are promising alternatives to antibiotic treatment for chancroid.

[Bactericidal activity of serum and chemotherapy in sensitive and resistant exciter (author's transl)].

Science.gov (United States)

Eyer, H; Metz, H; Preac-Mursic, V

1975-11-21

Comparing examinations with Ampicillin sensitive and resistant bacteria-strains show that the bactericidal activity of serum is dependent on the bacteria-strains, on the Ampicillin sensitivity of the particular exciter and on the number of bacteria/ml (germ count). Bactericide effect could always be obtained with sensitive strains as a result of additional chemotherapy. With several resistant strains a bactericide effect could not be obtained in this case the continuous optimal Ampicillin addition was the decisive factor. Because of the extremely complicated process of the bactericide one should not make general conclusions from the individual experimental results.

Ceftiofur sodium, a broad-spectrum cephalosporin: evaluation in vitro and in vivo in mice.

Science.gov (United States)

Yancey, R J; Kinney, M L; Roberts, B J; Goodenough, K R; Hamel, J C; Ford, C W

1987-07-01

Ceftiofur sodium, a broad-spectrum beta-lactamase-resistant cephalosporin, was evaluated in vitro and in vivo in mice. Ceftiofur is the sodium salt of (6R, 7R)-7[( 2-amino-4-thiazolyl)-Z- (methoxyimino)acetyl]amino)-3-[( (2-furanylcarbonyl)thio]methyl)-8-oxo-5- thia-1-azabicyclo-[4.2.0]oct-2-ene-2-carboxylate. Minimal inhibitory concentration values were obtained with 264 strains representing 9 genera and 17 species of bacterial pathogens from cattle, swine, sheep, horses, poultry, dogs, cats, and human beings. Ceftiofur was more active than was ampicillin against all strains tested including beta-lactamase-producing organisms. In mice with systemic infections, ceftiofur was more active than or equivalent to ampicillin, cephalothin, cefamandole, cloxacillin, cefoperazone, or pirlimycin. These protection tests included infections with Escherichia coli, Haemophilus pleuropneumoniae, H somnus, Pasteurella haemolytica, P multocida, Salmonella typhimurium, or Staphylococcus aureus. In infant mice with E coli-induced lethal diarrhea and in mice with S aureus and E coli-induced mastitis, ceftiofur was comparable or more active than was ampicillin.

Substrate specificity, metal binding properties, and spectroscopic characterization of the DapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase from Haemophilus influenzae.

Science.gov (United States)

Bienvenue, David L; Gilner, Danuta M; Davis, Ryan S; Bennett, Brian; Holz, Richard C

2003-09-16

The catalytic and structural properties of divalent metal ion cofactor binding sites in the dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase (DapE) from Haemophilus influenzae were investigated. Co(II)-substituted DapE enzyme was 25% more active than the Zn(II)-loaded form of the enzyme. Interestingly, Mn(II) can activate DapE, but only to approximately 20% of the Zn(II)-loaded enzyme. The order of the observed k(cat) values are Co(II) > Zn(II) > Cd(II) > Mn(II) >Ni(II) approximately equal Cu(II) approximately equal Mg(II). DapE was shown to only hydrolyze L,L-N-succinyl-diaminopimelic acid (L,L-SDAP) and was inactive toward D,L-, L,D-, and D,D-SDAP. DapE was also inactive toward several acetylated amino acids as well as D,L-succinyl aminopimelate, which differs from the natural substrate, L,L-SDAP, by the absence of the amine group on the amino acid side chain. These data imply that the carboxylate of the succinyl moiety and the amine form important interactions with the active site of DapE. The affinity of DapE for one versus two Zn(II) ions differs by nearly 2.2 x 10(3) times (K(d1) = 0.14 microM vs K(d2) = 300 microM). In addition, an Arrhenius plot was constructed from k(cat) values measured between 16 and 35 degrees C and was linear over this temperature range. The activation energy for [ZnZn(DapE)] was found to be 31 kJ/mol with the remaining thermodynamic parameters calculated at 25 degrees C being DeltaG(++) = 64 kJ/mol, DeltaH(++) = 28.5 kJ/mol, and DeltaS(++) = -119 J mol(-1) K(-1). Electronic absorption and EPR spectra of [Co_(DapE)] and [CoCo(DapE)] indicate that the first Co(II) binding site is five-coordinate, while the second site is octahedral. In addition, any spin-spin interaction between the two Co(II) ions in [CoCo(DapE)] is very weak. The kinetic and spectroscopic data presented herein suggest that the DapE from H. influenzae has similar divalent metal binding properties to the aminopeptidase from Aeromonas proteolytica (AAP), and

Crystal structures of active fully assembled substrate- and product-bound complexes of UDP-N-acetylmuramic acid:L-alanine ligase (MurC) from Haemophilus influenzae.

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Mol, Clifford D; Brooun, Alexei; Dougan, Douglas R; Hilgers, Mark T; Tari, Leslie W; Wijnands, Robert A; Knuth, Mark W; McRee, Duncan E; Swanson, Ronald V

2003-07-01

UDP-N-acetylmuramic acid:L-alanine ligase (MurC) catalyzes the addition of the first amino acid to the cytoplasmic precursor of the bacterial cell wall peptidoglycan. The crystal structures of Haemophilus influenzae MurC in complex with its substrate UDP-N-acetylmuramic acid (UNAM) and Mg(2+) and of a fully assembled MurC complex with its product UDP-N-acetylmuramoyl-L-alanine (UMA), the nonhydrolyzable ATP analogue AMPPNP, and Mn(2+) have been determined to 1.85- and 1.7-A resolution, respectively. These structures reveal a conserved, three-domain architecture with the binding sites for UNAM and ATP formed at the domain interfaces: the N-terminal domain binds the UDP portion of UNAM, and the central and C-terminal domains form the ATP-binding site, while the C-terminal domain also positions the alanine. An active enzyme structure is thus assembled at the common domain interfaces when all three substrates are bound. The MurC active site clearly shows that the gamma-phosphate of AMPPNP is positioned between two bound metal ions, one of which also binds the reactive UNAM carboxylate, and that the alanine is oriented by interactions with the positively charged side chains of two MurC arginine residues and the negatively charged alanine carboxyl group. These results indicate that significant diversity exists in binding of the UDP moiety of the substrate by MurC and the subsequent ligases in the bacterial cell wall biosynthesis pathway and that alterations in the domain packing and tertiary structure allow the Mur ligases to bind sequentially larger UNAM peptide substrates.

Degradation of amoxicillin, ampicillin and cloxacillin antibiotics in aqueous solution by the UV/ZnO photocatalytic process

International Nuclear Information System (INIS)

Elmolla, Emad S.; Chaudhuri, Malay

2010-01-01

The study examined the effect of operating conditions (zinc oxide concentration, pH and irradiation time) of the UV/ZnO photocatalytic process on degradation of amoxicillin, ampicillin and cloxacillin in aqueous solution. pH has a great effect on amoxicillin, ampicillin and cloxacillin degradation. The optimum operating conditions for complete degradation of antibiotics in an aqueous solution containing 104, 105 and 103 mg/L amoxicillin, ampicillin and cloxacillin, respectively were: zinc oxide 0.5 g/L, irradiation time 180 min and pH 11. Under optimum operating conditions, complete degradation of amoxicillin, ampicillin and cloxacillin occurred and COD and DOC removal were 23.9 and 9.7%, respectively. The photocatalytic reactions under optimum conditions approximately followed a pseudo-first order kinetics with rate constant (k) 0.018, 0.015 and 0.029 min -1 for amoxicillin, ampicillin and cloxacillin, respectively. UV/ZnO photocatalysis can be used for amoxicillin, ampicillin and cloxacillin degradation in aqueous solution.

Antiviral Activities of Several Oral Traditional Chinese Medicines against Influenza Viruses.

Science.gov (United States)

Ma, Lin-Lin; Ge, Miao; Wang, Hui-Qiang; Yin, Jin-Qiu; Jiang, Jian-Dong; Li, Yu-Huan

2015-01-01

Influenza is still a serious threat to human health with significant morbidity and mortality. The emergence of drug-resistant influenza viruses poses a great challenge to existing antiviral drugs. Traditional Chinese medicines (TCMs) may be an alternative to overcome the challenge. Here, 10 oral proprietary Chinese medicines were selected to evaluate their anti-influenza activities. These drugs exhibit potent inhibitory effects against influenza A H1N1, influenza A H3N2, and influenza B virus. Importantly, they demonstrate potent antiviral activities against drug-resistant strains. In the study of mechanisms, we found that Xiaoqinglong mixture could increase antiviral interferon production by activating p38 MAPK, JNK/SAPK pathway, and relative nuclear transcription factors. Lastly, our studies also indicate that some of these medicines show inhibitory activities against EV71 and CVB strains. In conclusion, the 10 traditional Chinese medicines, as kind of compound combination medicines, show broad-spectrum antiviral activities, possibly also including inhibitory activities against strains resistant to available antiviral drugs.

Estudo Viriato: Actualização de dados de susceptibilidade aos antimicrobianos de bactérias responsáveis por infecções respiratórias adquiridas na comunidade em Portugal em 2003 e 2004

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J. Melo-Cristino

2006-01-01

Full Text Available Resumo: O Estudo Viriato é um estudo nacional, prospectivo e multicêntrico, de vigilância da susceptibilidade aos antimicrobianos de bactérias frequentemente responsáveis por infecções do aparelho respiratório adquiridas na comunidade. Nos anos de 2003 e 2004 participaram 29 laboratórios de todo o país. Isolaram-se 2945 microrganismos que foram estudados num laboratório coordenador. Das 513 estirpes de Streptococcus pyogenes de doentes com amigdalo-faringite aguda, todas eram susceptíveis à penicilina e outros antibióticos beta-lactâmicos, mas 18,9% eram resistentes à eritromicina, claritromicina e azitromicina. Nas estirpes resistentes foi mais frequente o fenótipo M (67,0% que confere resistência à eritromicina (CIM90=16 mg/L, claritromicina e azitromicina, mas susceptibilidade à clindamicina (CIM90=0,094 mg/L. De doentes com infecção do aparelho respiratório inferior estudaram-se 1300 estirpes de Streptococcus pneumoniae (pneumococos, 829 de Haemophilus influenzae e 303 de Moraxella catarrhalis. Em S. pneumoniae, 18,4% das estirpes eram resistentes à penicilina (3,5% com resistência elevada, 7,1% à cefuroxima, 0,5% à amoxicilina, 0,5% à amoxicilina/clavulanato, 18,8% à eritromicina, claritromicina e azitromicina, 14,5 % à tetraciclina, 16,5% ao cotrimoxazol e 0,4% à levofloxacina. Nas estirpes resistentes aos macrólidos, dominou o fenótipo MLSB (83,7%, caracterizado por resistência elevada (CIM90 >256 mg/L à eritromicina, claritromicina, azitromicina e clindamicina. Produziam beta-lactamase 10,0% de H. influenzae e 96,4% de M. catarrhalis. Em H. influenzae demonstrou-se 5,5% de resistência à claritromicina e 13,4% ao cotrimoxazol. A quase totalidade das estirpes era susceptível à amoxicilina / clavulanato, cefuroxima, azitromicina, tetraciclina e ciprofloxacina. Em M. catarrhalis a resistência ao co-trimoxazol foi de 27,1% e à tetraciclina de 1,0%. Todas as estirpes eram susceptíveis à amoxicilina

Evaluación rápida del impacto de la vacuna contra Haemophilus influenzae serotipo b en Colombia

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Clara Inés Agudelo

2000-09-01

Full Text Available En 1998, el Ministerio de Salud de Colombia inició la vacunación contra Haemophilus influenzae b (Hib en menores de 1 año. En 1999 se evaluó el impacto de esta intervención en la incidencia de la meningitis bacteriana aguda (MBA utilizando los datos del sistema de vigilancia por laboratorio que coordina desde 1994 el Grupo de Microbiología del Instituto Nacional de Salud. En el análisis se comparó el número anual de casos de meningitis por Hib en niños menores de 1 año que se diagnosticaron en el sistema de vigilancia, antes de introducirse la vacuna, con el número de casos registrados durante el primer año después de iniciada la vacunación. El número de casos esperado, según el promedio anual de los diagnosticados entre junio de 1994 y mayo de 1998, se comparó con el número de casos observado después de la vacunación entre junio de 1998 y mayo de 1999. Para controlar la calidad del sistema de vigilancia, se realizó un estudio similar de los casos de meningitis por Streptococcus pneumoniae. En los análisis se incluyeron solamente los datos de los departamentos que habían participado con mayor regularidad en la vigilancia. Entre 1994 y 1998 se confirmaron, respectivamente, 45, 37, 61, 64 y 31 casos de MBA por Hib, mientras que en el período posvacunal se esperaban 52 casos y se observaron 31 (P < 0,001. Durante los mismos períodos anuales se confirmaron también 32, 26, 43, 48 y 42 casos de MBA por S. pneumoniae en menores de 5 años, cifras que no representaron una disminución significativa del número de casos esperados. Sin embargo, la reducción observada en los casos de meningitis por Hib fue de 40%, porción no atribuible a cambios en el sistema de vigilancia. Concluimos, por lo tanto, que esta disminución se debió en su mayor parte a los efectos de la vacunación.

Evaluación rápida del impacto de la vacuna contra Haemophilus influenzae serotipo b en Colombia

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Agudelo Clara Inés

2000-01-01

Full Text Available En 1998, el Ministerio de Salud de Colombia inició la vacunación contra Haemophilus influenzae b (Hib en menores de 1 año. En 1999 se evaluó el impacto de esta intervención en la incidencia de la meningitis bacteriana aguda (MBA utilizando los datos del sistema de vigilancia por laboratorio que coordina desde 1994 el Grupo de Microbiología del Instituto Nacional de Salud. En el análisis se comparó el número anual de casos de meningitis por Hib en niños menores de 1 año que se diagnosticaron en el sistema de vigilancia, antes de introducirse la vacuna, con el número de casos registrados durante el primer año después de iniciada la vacunación. El número de casos esperado, según el promedio anual de los diagnosticados entre junio de 1994 y mayo de 1998, se comparó con el número de casos observado después de la vacunación entre junio de 1998 y mayo de 1999. Para controlar la calidad del sistema de vigilancia, se realizó un estudio similar de los casos de meningitis por Streptococcus pneumoniae. En los análisis se incluyeron solamente los datos de los departamentos que habían participado con mayor regularidad en la vigilancia. Entre 1994 y 1998 se confirmaron, respectivamente, 45, 37, 61, 64 y 31 casos de MBA por Hib, mientras que en el período posvacunal se esperaban 52 casos y se observaron 31 (P < 0,001. Durante los mismos períodos anuales se confirmaron también 32, 26, 43, 48 y 42 casos de MBA por S. pneumoniae en menores de 5 años, cifras que no representaron una disminución significativa del número de casos esperados. Sin embargo, la reducción observada en los casos de meningitis por Hib fue de 40%, porción no atribuible a cambios en el sistema de vigilancia. Concluimos, por lo tanto, que esta disminución se debió en su mayor parte a los efectos de la vacunación.

New treatments for influenza

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Barik Sailen

2012-09-01

Full Text Available Abstract Influenza has a long history of causing morbidity and mortality in the human population through routine seasonal spread and global pandemics. The high mutation rate of the RNA genome of the influenza virus, combined with assortment of its multiple genomic segments, promote antigenic diversity and new subtypes, allowing the virus to evade vaccines and become resistant to antiviral drugs. There is thus a continuing need for new anti-influenza therapy using novel targets and creative strategies. In this review, we summarize prospective future therapeutic regimens based on recent molecular and genomic discoveries.

Zinc Finger Nuclease: A New Approach to Overcome Beta-Lactam Antibiotic Resistance

Science.gov (United States)

Shahbazi Dastjerdeh, Mansoureh; Kouhpayeh, Shirin; Sabzehei, Faezeh; Khanahmad, Hossein; Salehi, Mansour; Mohammadi, Zahra; Shariati, Laleh; Hejazi, Zahra; Rabiei, Parisa; Manian, Mostafa

2016-01-01

Background: The evolution of antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) has been accelerated recently by the indiscriminate application of antibiotics. Antibiotic resistance has challenged the success of medical interventions and therefore is considered a hazardous threat to human health. Objectives: The present study aimed to describe the use of zinc finger nuclease (ZFN) technology to target and disrupt a plasmid-encoded β-lactamase, which prevents horizontal gene transfer-mediated evolution of ARBs. Materials and Methods: An engineered ZFN was designed to target a specific sequence in the ampicillin resistance gene (ampR) of the pTZ57R plasmid. The Escherichia coli bacteria already contained the pZFN kanamycin-resistant (kanaR) plasmid as the case or the pP15A, kanaR empty vector as the control, were transformed with the pTZ57R; the ability of the designed ZFN to disrupt the β-lactamase gene was evaluated with the subsequent disturbed ability of the bacteria to grow on ampicillin (amp) and ampicillin-kanamycin (amp-kana)-containing media. The effect of mild hypothermia on the ZFN gene targeting efficiency was also evaluated. Results: The growth of bacteria in the case group on the amp and amp-kana-containing media was significantly lower compared with the control group at 37°C (P < 0.001). Despite being more efficient in hypothermic conditions at 30°C (P < 0.001), there were no significant associations between the incubation temperature and the ZFN gene targeting efficiency. Conclusions: Our findings revealed that the ZFN technology could be employed to overcome ampicillin resistance by the targeted disruption of the ampicillin resistance gene, which leads to inactivation of β-lactam synthesis. Therefore, ZFN technology could be engaged to decrease the antibiotic resistance issue with the construction of a ZFN archive against different ARGs. To tackle the resistance issue at the environmental level, recombinant phages

Reclassification of Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, Haemophilus paraphrophilus and Haemophilus segnis as Aggregatibacter actinomycetemcomitans gen. nvo., comb. nov., Aggregatibacter aphrophilus comb. nov. and Aggregatibacter segnis comb. nov., and emended description of Aggregatibacter aphrophilus to include V factor-dependent and V factor-independent isolates

DEFF Research Database (Denmark)

Nørskov-Lauritsen, N.; Kilian, Mogens

2006-01-01

-independent growth was identified in Haemophilus aphrophilus. The gene encodes a polypeptide of 462 amino acids that shows 74.5 % amino acid sequence identity to the corresponding enzyme from Actinobacillus actinomycetemcomitans. Ten isolates of Haemophilus paraphrophilus all carried a nadV pseudogene. DNA from...... Haemophilus aphrophilus was able to transform Haemophilus paraphrophilus into the NAD-independent phenotype. The transformants carried a full-length nadV inserted in the former locus of the pseudogene. The DNA-DNA relatedness between the type strains of Haemophilus aphrophilus and Haemophilus paraphrophilus...

Influenza interaction with cocirculating pathogens and its impact on surveillance, pathogenesis, and epidemic profile: A key role for mathematical modelling.

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Lulla Opatowski

2018-02-01

Full Text Available Evidence is mounting that influenza virus interacts with other pathogens colonising or infecting the human respiratory tract. Taking into account interactions with other pathogens may be critical to determining the real influenza burden and the full impact of public health policies targeting influenza. This is particularly true for mathematical modelling studies, which have become critical in public health decision-making. Yet models usually focus on influenza virus acquisition and infection alone, thereby making broad oversimplifications of pathogen ecology. Herein, we report evidence of influenza virus interactions with bacteria and viruses and systematically review the modelling studies that have incorporated interactions. Despite the many studies examining possible associations between influenza and Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Neisseria meningitidis, respiratory syncytial virus (RSV, human rhinoviruses, human parainfluenza viruses, etc., very few mathematical models have integrated other pathogens alongside influenza. The notable exception is the pneumococcus-influenza interaction, for which several recent modelling studies demonstrate the power of dynamic modelling as an approach to test biological hypotheses on interaction mechanisms and estimate the strength of those interactions. We explore how different interference mechanisms may lead to unexpected incidence trends and possible misinterpretation, and we illustrate the impact of interactions on public health surveillance using simple transmission models. We demonstrate that the development of multipathogen models is essential to assessing the true public health burden of influenza and that it is needed to help improve planning and evaluation of control measures. Finally, we identify the public health, surveillance, modelling, and biological challenges and propose avenues of research for the coming years.

Chronic obstructive pulmonary disease and asthma-associated Proteobacteria, but not commensal Prevotella spp., promote Toll-like receptor 2-independent lung inflammation and pathology

DEFF Research Database (Denmark)

Larsen, Jeppe Madura; Musavian, Hanieh Sadat; Butt, Tariq Mahmood

2015-01-01

B, non-typeable Haemophilus influenzae and Moraxella catarrhalis). The commensal Prevotella spp. and pathogenic Proteobacteria were found to exhibit intrinsic differences in innate inflammatory capacities on murine lung cells in vitro. In vivo in mice, non-typeable H.influenzae induced severe Toll...... response to three Gram-negative commensal Prevotella strains (Prevotella melaninogenica, Prevotella nanceiensis and Prevotella salivae) and three Gram-negative pathogenic Proteobacteria known to colonize lungs of patients with chronic obstructive pulmonary disease (COPD) and asthma (Haemophilus influenzae...

Imipenem heteroresistance in nontypeable Haemophilus influenzae is linked to a combination of altered PBP3, slow drug influx and direct efflux regulation.

Science.gov (United States)

Cherkaoui, A; Diene, S M; Renzoni, A; Emonet, S; Renzi, G; François, P; Schrenzel, J

2017-02-01

To investigate the potential roles of PBPs, efflux pumps and slow drug influx for imipenem heteroresistance in nontypeable Haemophilus influenzae (NTHi). Fifty-nine NTHi clinical isolates examined in this study were collected at Geneva University Hospitals between 2009 and 2014. Alterations in PBPs were investigated by gene sequencing. To evaluate the affinities of the PBPs to imipenem, steady-state concentration-response experiments were carried out using imipenem in a competition assay with Bocillin-FL. The effect of the carbonyl cyanide m-chlorophenylhydrazone (CCCP) on imipenem susceptibility was assessed using broth dilution and viable cell counting. Using whole-genome sequencing, we explored the potential roles of outer membrane protein P2 (OmpP2), LytM proteins and the dcw gene cluster in imipenem heteroresistance. All 46 imipenem-heteroresistant isolates (IMI hR ) harboured amino acid substitutions in the ftsI gene, which encodes PBP3, corresponding to 25 different mutation patterns that varied from the ftsI gene mutation patterns found in imipenem-susceptible isolates. Among all PBPs, the highest affinity to imipenem was documented for PBP3 (IC 50 , 0.004 μg/mL). Different amino acid substitutions and insertions were noted in OmpP2, suggesting a relationship with imipenem heteroresistance. The IMI hR isolates were affected by CCCP differently and displayed a higher percentage of killing by imipenem in CCCP-treated cells at concentrations ranging between 0.5 and 8 μg/mL. The present study provides robust evidence indicating that in combination with the altered PBP3, the slowed drug influx and its enhanced efflux due to the loss of regulation led to the development of imipenem heteroresistance in NTHi. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Mercury and antibiotic resistance in Enterobacteriaceae: an experimental study on pigs

Energy Technology Data Exchange (ETDEWEB)

Laub-Kupersztejn, R; Thomas, J; Pohl, P

1974-01-01

Tests on faeces from 5 different groups of pigs, showed that 47.2% of the coliforms present were resistant to mercury ions. None of the 3127 bacteria examined were resistant to cadmium ions. The resistance of these strains to mercury was mainly associated with resistance to one or more antibiotics (98%). Feeding the animals with ampicillin (20 ppm) led to modification of the Escherichia coli in the alimentary tract, with ampicillin and mercury resistant strains emerging in great number. These resistance characters could be wholly, or partially, transferred to a sensitive strain of E. coli, thus suggesting that they were mediated by R-factors. The existence of a plasmid resistant only to mercury ions was demonstrated. 9 references, 4 tables.

21 CFR 520.90a - Ampicillin capsules.

Science.gov (United States)

2010-04-01

.... Use of the drug is contraindicated in animals with a history of an allergic reaction to any of the... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ampicillin capsules. 520.90a Section 520.90a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL...

Pharyngeal colonization and drug resistance profiles of Morraxella catarrrhalis, Streptococcus pneumoniae, Staphylococcus aureus, and Haemophilus influenzae among HIV infected children attending ART Clinic of Felegehiwot Referral Hospital, Ethiopia.

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Wondemagegn Mulu

Full Text Available Asymptomatic pharyngeal colonization by potential bacteria is the primary reservoir for bacterial species within a population and is considered a prerequisite for development of major childhood diseases such as sinusitis, otitis media, pneumonia, bacteremia, and meningitis. However, there is dearth of data on the colonization and drug resistance pattern of the main bacterial pathogens in the pharynx of HIV infected children in Ethiopia. Therefore, this study determined the pharyngeal colonization and drug resistance profile of bacterial pathogens in HIV infected children attending ART clinic of Felegehiwot Referral Hospital (FHRH, Amhara Region, Ethiopia.A hospital based cross-sectional study was conducted from May 2016 to June 2017 at the ART clinic of FHRH. A total of 300 HIV infected children were enrolled in the study. Data on socio-demographic characteristics of the study participants were collected with face-to-face interview and patient-card review using structured questionnaire. Bacterial species were identified using standard bacteriological techniques. Drug susceptibility testing was performed using disk diffusion technique. Chi-square test was done to determine associations among variables.The median age of the participants was 11 years. Overall, 153 (51% of children were colonized by respiratory bacteria in their pharynx. Colonization rate was higher in children from mothers who had attained college and above levels of education than others (P = 0.04. It was also higher in children without the sign of malnutrition than others (P = 0.004. The colonization rate of S.aureus, M.catarrhalis, S.pneumoniae and H.influenzae were 88 (29%, 37 (12.3%, 31 (10.3% and 6 (2%, respectively. S.aureus-M.catarrhalis concurrent colonization was found in 14 (4.7% of children. Age (P = 0.03, schooling (P = 0.045 and history of running nose (P = 0.043 were significantly associated with S.aureus colonization. Living in urban setting (P = 0.042 and children

CLINICAL CHARACTERISTICS AND ANTIBIOTIC RESISTANCE PATTERN OF PATHOGENS IN PEDIATRIC URINARY TRACT INFECTION.

Science.gov (United States)

Amornchaicharoensuk, Yupaporn

2016-09-01

Medical records of children less than 15-years of age admitted to hospital for urinary tract infection (UTI) from January 2010 to December 2014 were reviewed. Among 100 children (59% males and 41% females) with upper UTI, the most common pathogen (88%) was Escherichia coli, of which 69% were nonextended spectrum beta-lactamase (ESBL) and 19 % ESBL producers. Resistance to ampicillin and trimethoprim/sulfamethoxazole was 90% and 60%, respectively. All ESBL-producing E. coli were resistant to ampicillin and third generation cephalosporins (cefotaxime and ceftriaxone), while 87% and 1.5% of non ESBL-producing E. coli were resistant to ampicillin and the two third generation cephalosporins, respectively. These data highlight the high prevalence of ESBL-producing E. coli in pediatric UTI and the potential problem in treating such infections.

Antibiotic resistant enterococci—Tales of a drug resistance gene trafficker

DEFF Research Database (Denmark)

Werner, Guido; Coque, Teresa M.; Franz, Charles M.A.P.

2013-01-01

Enterococci have been recognized as important hospital-acquired pathogens in recent years, and isolates of E. faecalis and E. faecium are the third- to fourth-most prevalent nosocomial pathogen worldwide. Acquired resistances, especially against penicilin/ampicillin, aminoglycosides (high-level) ...

Evaluation of hard gelatin capsules and hydroxypropyl methylcellulose containing ampicillin

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Graziella Gonçalves Weigert

2012-01-01

Full Text Available This study aims to develop and evaluate formulations containing ampicillin in capsules of gelatin and hydroxypropyl methylcellulose (HPMC. Two formulations (A and B were developed. The final product quality was evaluated by testing for quality control and the results were in agreement with the Brazilian Pharmacopoeia. The formulations with HPMC capsules showed lower percentages of drug dissolved (99.67%, HPMC-A and 87.70%, HPMC-B than the gelatin (100.18%, GEL-A and 101.16% GEL-B. Because of the delay of the ampicillin release observed in the dissolution profiles, it becomes necessary to evaluate the drugs that can be conditioned in the HPMC capsules.

Antibiotic resistance of Streptococcus pneumoniae in children with acute otitis media treatment failure.

Science.gov (United States)

Zielnik-Jurkiewicz, Beata; Bielicka, Anna

2015-12-01

The emergence of antibiotic-resistant bacteria is a major cause of treatment failure in children with acute otitis media (AOM). This study aimed to analyze the types of bacterial strains in fluid isolated from the middle ear of children with AOM who did not respond to oral antibiotic treatment. We also determined the antibiotic resistance of the most frequently isolated bacterial strain (Streptococcus pneumoniae) found in these children. This was a prospective study of 157 children with AOM aged from 6 months to 7 years admitted due to unsuccessful oral antibiotic treatment. All children underwent a myringotomy, and samples of the middle ear fluid were collected for bacteriological examination. Positive bacterial cultures were obtained in 104 patients (66.2%), with Streptococcus pneumoniae (39.69%), Haemophilus influenzae (16.03%) Staphylococcus aureus (16.03%), Staphylococcus haemolyticus (6.9%) and Streptococcus pyogenes (5.34%) found most frequently. The majority (65.4%) of S. pneumoniae strains were penicillin-intermediate-resistant or penicillin-resistant, and 67.2% strains of S. pneumoniae were multidrug-resistant. We identified S. pneumoniae as the most frequently isolated pathogen from the middle ear in children with AOM treatment failure and determined that the majority of strains were antibiotic-resistant. We propose that the microbiological identification of bacterial strains and their degree of antibiotic resistance should be performed prior to therapy in order to choose the most appropriate antibiotic therapy for children with AOM treatment failure. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Ampicillin-Ester Bonded Branched Polymers: Characterization, Cyto-, Genotoxicity and Controlled Drug-Release Behaviour

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Ewa Oledzka

2014-06-01

Full Text Available The development and characterization of novel macromolecular conjugates of ampicillin using branched biodegradable polymers has been described in this study. The conjugates have been prepared coupling the β-lactam antibiotic with branched polymer matrices based on the natural oligopeptide core. The cyto- and genotoxicity of the synthesized polymers were evaluated with a bacterial luminescence test, two protozoan assays and Salmonella typhimurium TA1535. The presence of a newly formed covalent bond between the drug and the polymer matrices was confirmed by 1H-NMR and FTIR studies. A drug content (15.6 and 10.2 mole % in the macromolecular conjugates has been determined. The obtained macromolecular products have been subjected to further in vitro release studies. The total percentage of ampicillin released after 21 days of incubation was nearly 60% and 14% and this resulted from the different physicochemical properties of the polymeric matrices. This is the first report on the application of branched biodegradable polymeric matrices for the covalent conjugation of ampicillin. The obtained results showed that the synthesized macromolecular drug-conjugates might slowly release the active drug molecule and improve the pharmacokinetics of ampicillin.

Antimicrobial resistance 1979-2009 at Karolinska hospital, Sweden: normalized resistance interpretation during a 30-year follow-up on Staphylococcus aureus and Escherichia coli resistance development.

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Kronvall, Göran

2010-09-01

To utilize a material of inhibition zone diameter measurements from disc diffusion susceptibility tests between 1979 and 2009, an objective setting of epidemiological breakpoints was necessary because of methodological changes. Normalized resistance interpretation (NRI) met this need and was applied to zone diameter histograms for Staphylococcus aureus and Escherichia coli isolates. The results confirmed a slow resistance development as seen in Northern countries. The S. aureus resistance levels for erythromycin, clindamycin and fusidic acid in 2009 were 3.2%, 1.8% and 1.4% with denominator correction. A rise in resistance to four antimicrobials in 1983 was probably because of a spread of resistant Methicillin Susceptible Staphylococcus Aureus (MSSA). For E. coli, the denominator-corrected resistance levels in 2009 were 27% for ampicillin, around 3% for third-generation cephalosporins, 0.1% for imipenem, 2.5% for gentamicin, 19% for trimethoprim, 4.5% for co-trimoxazole, 1.2% for nitrofurantoin and 9% for ciprofloxacin. The temporal trends showed a rise in fluoroquinolone resistance from 1993, a parallel increase in gentamicin resistance, a substantial increase in trimethoprim and sulphonamide resistance in spite of decreased consumption, and a steady rise in ampicillin resistance from a constant level before 1989. A short review of global resistance surveillance studies is included.

Changes in IgA protease expression are conferred by changes in genomes during persistent infection by nontypeable Haemophilus influenzae in chronic obstructive pulmonary disease.

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Gallo, Mary C; Kirkham, Charmaine; Eng, Samantha; Bebawee, Remon S; Kong, Yong; Pettigrew, Melinda M; Tettelin, Hervé; Murphy, Timothy F

2018-05-14

Nontypeable Haemophilus influenzae (NTHi) is an exclusively human pathobiont that plays a critical role in the course and pathogenesis of chronic obstructive pulmonary disease (COPD). NTHi causes acute exacerbations of COPD and also causes persistent infection of the lower airways. NTHi expresses four IgA protease variants (A1, A2, B1, and B2) that play different roles in virulence. Expression of IgA proteases varies among NTHi strains, but little is known about the frequency and mechanisms by which NTHi modulates IgA protease expression during infection in COPD. To assess expression of IgA protease during natural infection in COPD, we studied IgA protease expression of 101 persistent strains (median duration of persistence 161 days, range 2 to 1422) collected longitudinally from patients enrolled in a 20-year study of COPD upon initial acquisition and immediately before clearance from the host. Upon acquisition, 89 (88%) expressed IgA protease. A total of 16 of 101 (16%) strains of NTHi altered expression of IgA protease during persistence. Indels and slipped-strand mispairing of mononucleotide repeats conferred changes in expression of igaA1, igaA2, and igaB1 Strains with igaB2 underwent frequent changes in expression of IgA protease B2 during persistence, mediated by slipped-strand mispairing of a 7-nucleotide repeat, TCAAAAT, within the open reading frame of igaB2 We conclude that changes in iga gene sequences result in changes in expression of IgA proteases by NTHi during persistent infection in the respiratory tract of patients with COPD. Copyright © 2018 American Society for Microbiology.

tion and/or treatment of influenza virus infections

African Journals Online (AJOL)

Repro

more frequent in children and more seri- ous in the elderly, ... The main option for the prevention of influenza and ... rapid development of influenza virus resistance ... drugs that affect the CNS, particu- .... include employees of hospitals, clinics ...

IMMUNOGENICITY AND SAFETY OF QUINVAXEM® (DIPHTHERIA, TETANUS, WHOLE-CELL PERTUSSIS, HEPATITIS B AND HAEMOPHILUS INFLUENZAE TYPE B VACCINE) GIVEN TO VIETNAMESE INFANTS AT 2 TO 4 MONTHS OF AGE.

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Huu, Tran Ngoc; Phuong, Nguyen Thi Minh; Toan, Nguyen Trong; Thang, Ho Vinh

2015-07-01

Vietnam plans to replace the routine childhood diphtheria, pertussis and tetanus combination (DPT) vaccine with a pentavalent vaccine. The present study was performed to assess the immunogenicity and safety of the combined diphtheria, tetanus, whole-cell pertussis, hepatitis B (HepB), and Haemophilus influenzae type b (Hib) (DTwP-HepB-Hib) Quinvaxem® vaccine in children. A total of 131 infants received the Quinvaxem® vaccine at 2, 3 and 4 months. Antibody levels were measured at baseline, at one month after the third injection and one year after the first injection. Seroprotection rates were high for each vaccine antigen at one month after the third dose: 93.1% for diphtheria, 98.5% for tetanus, 99.2% for pertussis (seroconversion rate), 93.1% for HepB, and 100% for Hib (anti-PRP ≥ 0.15 µg/ml). The rate of children with protective antibodies persisting at one year after the first dose was 88.4% for diphtheria, 49.6% for pertussis, 82.2% for tetanus, 76.7% for HepB and 97.7% for Hib (anti-PRP ≥ 0.15 µg/ml). The Quinvaxem® vaccine was well tolerated and has a low rate of adverse events. Quinvaxem® given at 2, 3 and 4 months of age was immunogenic and safe for primary immunization among infants in Vietnam.

Cleavage of a recombinant human immunoglobulin A2 (IgA2)-IgA1 hybrid antibody by certain bacterial IgA1 proteases

DEFF Research Database (Denmark)

Senior, B; Dunlop, JI; Batten, MR

2000-01-01

, Streptococcus pneumoniae, S. sanguis, Neisseria meningitidis types 1 and 2, N. gonorrhoeae types 1 and 2, and Haemophilus influenzae type 2. Thus, for these enzymes the recognition site for IgA1 cleavage is contained within half of the IgA1 hinge region; additional distal elements, if required, are provided...... by either an IgA1 or an IgA2 framework. In contrast, the IgA2/A1 hybrid appeared to be resistant to cleavage with S. oralis and some H. influenzae type 1 IgA1 proteases, suggesting these enzymes require additional determinants for efficient substrate recognition....

Sales of oseltamivir in Norway prior to the emergence of oseltamivir resistant influenza A(H1N1 viruses in 2007–08

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Hungnes Olav

2009-05-01

Full Text Available Abstract Background An unprecedented high proportion of oseltamivir resistant influenza A(H1N1 viruses emerged in the 2007–08 influenza season. In Norway, two thirds of all tested A(H1N1 viruses were resistant to the antiviral drug. In order to see if this emergence could be explained by a drug induced selection pressure, we analysed data on the sales of oseltamivir in Norway for the years 2002–07. Methods We used data from two sources; the Norwegian Drug Wholesales Statistics Database and the Norwegian Prescription Database (NorPD, for the years 2002–2007. We calculated courses sold of oseltamivir (Tamiflu® per 1000 inhabitants per year. Results Our data showed that, except for the years 2005 and 2006, sales of oseltamivir were low in Norway; courses sold per 1000 inhabitants varied between 0.17–1.64. The higher sales in 2005 and 2006 we believe were caused by private stockpiling in fear of a pandemic, and do not represent actual usage. Conclusion A drug induced selection pressure was probably not the cause of the emergence of oseltamivir resistant influenza A(H1N1 viruses in 2007–08 in Norway.

Detection of antibiotic resistance and tetracycline resistance genes in Enterobacteriaceae isolated from the Pearl rivers in South China

International Nuclear Information System (INIS)

Tao Ran; Ying Guangguo; Su Haochang; Zhou Hongwei; Sidhu, Jatinder P.S.

2010-01-01

This study investigated antibiotic resistance profiles and tetracycline resistance genes in Enterobacteriaceae family isolates from the Pearl rivers. The Enterobacteriaceae isolates were tested for susceptibility to seven antibiotics ampicillin, chloramphenicol, ciprofloxacin, levofloxacin, sulphamethoxazole/trimethoprim, tetracycline and trimethoprim. In Liuxi reservoir, with an exception to ampicillin resistant strains (11%) no other antibiotic resistance bacterial strains were detected. However, multiple drug resistance in bacterial isolates from the other sites of Pearl rivers was observed which is possibly due to sewage discharge and input from other anthropogenic sources along the rivers. Four tetracycline resistance genes tet A, tet B, tet C and tet D were detected in the isolates from the rivers. The genes tet A and tet B were widely detected with the detection frequencies of 43% and 40% respectively. Ciprofloxacin and levofloxacin resistant enteric bacteria were also isolated from the pig and duck manures which suggest a wider distribution of human specific drugs in the environment. This investigation provided a baseline data on antibiotic resistance profiles and tetracycline resistance genes in the Pearl rivers delta. - High rates of antibiotic resistance in Enterobacteriaceae from river water are attributed to wastewater contamination.

Detection of antibiotic resistance and tetracycline resistance genes in Enterobacteriaceae isolated from the Pearl rivers in South China

Energy Technology Data Exchange (ETDEWEB)

Tao Ran [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Ying Guangguo, E-mail: guangguo.ying@gmail.co [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Su Haochang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Zhou Hongwei [Department of Environmental Health, School of Public Health and Tropical Medicine, Southern Medical University, 1838 North Guangzhou Street, Baiyun District, Guangzhou 510515 (China); Sidhu, Jatinder P.S. [CSIRO Land and Water, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia QLD 4067 (Australia)

2010-06-15

This study investigated antibiotic resistance profiles and tetracycline resistance genes in Enterobacteriaceae family isolates from the Pearl rivers. The Enterobacteriaceae isolates were tested for susceptibility to seven antibiotics ampicillin, chloramphenicol, ciprofloxacin, levofloxacin, sulphamethoxazole/trimethoprim, tetracycline and trimethoprim. In Liuxi reservoir, with an exception to ampicillin resistant strains (11%) no other antibiotic resistance bacterial strains were detected. However, multiple drug resistance in bacterial isolates from the other sites of Pearl rivers was observed which is possibly due to sewage discharge and input from other anthropogenic sources along the rivers. Four tetracycline resistance genes tet A, tet B, tet C and tet D were detected in the isolates from the rivers. The genes tet A and tet B were widely detected with the detection frequencies of 43% and 40% respectively. Ciprofloxacin and levofloxacin resistant enteric bacteria were also isolated from the pig and duck manures which suggest a wider distribution of human specific drugs in the environment. This investigation provided a baseline data on antibiotic resistance profiles and tetracycline resistance genes in the Pearl rivers delta. - High rates of antibiotic resistance in Enterobacteriaceae from river water are attributed to wastewater contamination.

Synergistic effect of interleukin 1 alpha on nontypeable Haemophilus influenzae-induced up-regulation of human beta-defensin 2 in middle ear epithelial cells

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Park Raekil

2006-01-01

Full Text Available Abstract Background We recently showed that beta-defensins have antimicrobial activity against nontypeable Haemophilus influenzae (NTHi and that interleukin 1 alpha (IL-1 alpha up-regulates the transcription of beta-defensin 2 (DEFB4 according to new nomenclature of the Human Genome Organization in human middle ear epithelial cells via a Src-dependent Raf-MEK1/2-ERK signaling pathway. Based on these observations, we investigated if human middle ear epithelial cells could release IL-1 alpha upon exposure to a lysate of NTHi and if this cytokine could have a synergistic effect on beta-defensin 2 up-regulation by the bacterial components. Methods The studies described herein were carried out using epithelial cell lines as well as a murine model of acute otitis media (OM. Human cytokine macroarray analysis was performed to detect the released cytokines in response to NTHi exposure. Real time quantitative PCR was done to compare the induction of IL-1 alpha or beta-defensin 2 mRNAs and to identify the signaling pathways involved. Direct activation of the beta-defensin 2 promoter was monitored using a beta-defensin 2 promoter-Luciferase construct. An IL-1 alpha blocking antibody was used to demonstrate the direct involvement of this cytokine on DEFB4 induction. Results Middle ear epithelial cells released IL-1 alpha when stimulated by NTHi components and this cytokine acted in an autocrine/paracrine synergistic manner with NTHi to up-regulate beta-defensin 2. This synergistic effect of IL-1 alpha on NTHi-induced beta-defensin 2 up-regulation appeared to be mediated by the p38 MAP kinase pathway. Conclusion We demonstrate that IL-1 alpha is secreted by middle ear epithelial cells upon exposure to NTHi components and that it can synergistically act with certain of these molecules to up-regulate beta-defensin 2 via the p38 MAP kinase pathway.

Long-term persistence of immunity and B-cell memory following Haemophilus influenzae type B conjugate vaccination in early childhood and response to booster.

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Perrett, K P; John, T M; Jin, C; Kibwana, E; Yu, L-M; Curtis, N; Pollard, A J

2014-04-01

Protection against Haemophilus influenzae type b (Hib), a rapidly invading encapsulated bacteria, is dependent on maintenance of an adequate level of serum antibody through early childhood. In many countries, Hib vaccine booster doses have been implemented after infant immunization to sustain immunity. We investigated the long-term persistence of antibody and immunological memory in primary-school children following infant (with or without booster) Hib vaccination. Anti-polyribosylribitol phosphate (PRP) immunoglobulin G (IgG) concentration and the frequency of circulating Hib-specific memory B cells were measured before a booster of a Hib-serogroup C meningococcal (MenC) conjugate vaccine and again 1 week, 1 month, and 1 year after the booster in 250 healthy children aged 6-12 years in an open-label phase 4 clinical study. Six to 12 years following infant priming with 3 doses of Hib conjugate vaccine, anti-PRP IgG geometric mean concentrations were 3.11 µg/mL and 0.71 µg/mL and proportions with anti-PRP IgG ≥1.0 µg/mL were 79% and 43% in children who had or had not, respectively, received a fourth Hib conjugate vaccine dose (mean age, 3.9 years). Higher baseline and post-Hib-MenC booster responses (anti-PRP IgG and memory B cells) were found in younger children and in those who had received a fourth Hib dose. Sustained Hib conjugate vaccine-induced immunity in children is dependent on time since infant priming and receipt of a booster. Understanding the relationship between humoral and cellular immunity following immunization with conjugate vaccines may direct vaccine design and boosting strategies to sustain individual and population immunity against encapsulated bacteria in early childhood. Clinical Trials Registration ISRCTN728588998.

Disease: H01330 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available H01330 Brazilian purpuric fever (BPF) Brazilian purpuric fever (BPF), which is cau...on of Haemophilus influenzae biogroup aegyptius (Haemophilus aegyptius) strains associated with Brazil

Screening for Neuraminidase Inhibitor Resistance Markers among Avian Influenza Viruses of the N4, N5, N6, and N8 Neuraminidase Subtypes.

Science.gov (United States)

Choi, Won-Suk; Jeong, Ju Hwan; Kwon, Jin Jung; Ahn, Su Jeong; Lloren, Khristine Kaith S; Kwon, Hyeok-Il; Chae, Hee Bok; Hwang, Jungwon; Kim, Myung Hee; Kim, Chul-Joong; Webby, Richard J; Govorkova, Elena A; Choi, Young Ki; Baek, Yun Hee; Song, Min-Suk

2018-01-01

Several subtypes of avian influenza viruses (AIVs) are emerging as novel human pathogens, and the frequency of related infections has increased in recent years. Although neuraminidase (NA) inhibitors (NAIs) are the only class of antiviral drugs available for therapeutic intervention for AIV-infected patients, studies on NAI resistance among AIVs have been limited, and markers of resistance are poorly understood. Previously, we identified unique NAI resistance substitutions in AIVs of the N3, N7, and N9 NA subtypes. Here, we report profiles of NA substitutions that confer NAI resistance in AIVs of the N4, N5, N6, and N8 NA subtypes using gene-fragmented random mutagenesis. We generated libraries of mutant influenza viruses using reverse genetics (RG) and selected resistant variants in the presence of the NAIs oseltamivir carboxylate and zanamivir in MDCK cells. In addition, two substitutions, H274Y and R292K (N2 numbering), were introduced into each NA gene for comparison. We identified 37 amino acid substitutions within the NA gene, 16 of which (4 in N4, 4 in N5, 4 in N6, and 4 in N8) conferred resistance to NAIs (oseltamivir carboxylate, zanamivir, or peramivir) as determined using a fluorescence-based NA inhibition assay. Substitutions conferring NAI resistance were mainly categorized as either novel NA subtype specific (G/N147V/I, A246V, and I427L) or previously reported in other subtypes (E119A/D/V, Q136K, E276D, R292K, and R371K). Our results demonstrate that each NA subtype possesses unique NAI resistance markers, and knowledge of these substitutions in AIVs is important in facilitating antiviral susceptibility monitoring of NAI resistance in AIVs. IMPORTANCE The frequency of human infections with avian influenza viruses (AIVs) has increased in recent years. Despite the availability of vaccines, neuraminidase inhibitors (NAIs), as the only available class of drugs for AIVs in humans, have been constantly used for treatment, leading to the inevitable emergence

Effective lethal mutagenesis of influenza virus by three nucleoside analogs.

Science.gov (United States)

Pauly, Matthew D; Lauring, Adam S

2015-04-01

Lethal mutagenesis is a broad-spectrum antiviral strategy that exploits the high mutation rate and low mutational tolerance of many RNA viruses. This approach uses mutagenic drugs to increase viral mutation rates and burden viral populations with mutations that reduce the number of infectious progeny. We investigated the effectiveness of lethal mutagenesis as a strategy against influenza virus using three nucleoside analogs, ribavirin, 5-azacytidine, and 5-fluorouracil. All three drugs were active against a panel of seasonal H3N2 and laboratory-adapted H1N1 strains. We found that each drug increased the frequency of mutations in influenza virus populations and decreased the virus' specific infectivity, indicating a mutagenic mode of action. We were able to drive viral populations to extinction by passaging influenza virus in the presence of each drug, indicating that complete lethal mutagenesis of influenza virus populations can be achieved when a sufficient mutational burden is applied. Population-wide resistance to these mutagenic agents did not arise after serial passage of influenza virus populations in sublethal concentrations of drug. Sequencing of these drug-passaged viral populations revealed genome-wide accumulation of mutations at low frequency. The replicative capacity of drug-passaged populations was reduced at higher multiplicities of infection, suggesting the presence of defective interfering particles and a possible barrier to the evolution of resistance. Together, our data suggest that lethal mutagenesis may be a particularly effective therapeutic approach with a high genetic barrier to resistance for influenza virus. Influenza virus is an RNA virus that causes significant morbidity and mortality during annual epidemics. Novel therapies for RNA viruses are needed due to the ease with which these viruses evolve resistance to existing therapeutics. Lethal mutagenesis is a broad-spectrum strategy that exploits the high mutation rate and the low

Investigation and Treatment of Fusidic Acid Resistance Among Methicillin-Resistant Staphylococcal Isolates from Egypt.

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Abouelfetouh, Alaa; Kassem, Mervat; Naguib, Marwa; El-Nakeeb, Moustafa

2017-01-01

Methicillin resistance among staphylococci isolated from patients in northern Egypt has escalated alarmingly in the past decade. Data about the prevalence of fusidic acid (FA) resistance in Egyptian clinical isolates are limited. This work investigates the prevalence and mechanism of FA resistance among 81 methicillin-resistant staphylococcal isolates from major hospitals of Alexandria, Egypt. Some combinations for treating infections due to resistant isolates were studied. Twenty-six isolates (32.1%) were FA resistant (minimum inhibitory concentrations [MICs] = 2-1,024 μg/ml), and fusB and fusC genes coding for FA resistance were detected in 30.77% and 34.62% of the FA-resistant strains, respectively. One highly resistant isolate, S502 (MIC = 1,024 μg/ml), possessed both genes. Plasmid curing resulted in fusB loss and MIC decrease by 16-64 folds. Conjugation caused acquisition of FA resistance among susceptible isolates. Serial passages in subinhibitory FA concentrations produced mutants with increased MIC by 4-32 folds. The combination of FA with rifampin, gentamicin, or ampicillin/sulbactam, in a subinhibitory concentration, was synergistic against the isolates, including serial passage mutants, decreasing number of survivors by an average of 2-4 logs. A relatively moderate rate of FA resistance was detected in Alexandria hospitals. Combination therapy with gentamicin, rifampin, or ampicillin/sulbactam is crucial to preserve the effectiveness of FA.

Pneumonia Prevention during a Humanitarian Emergency: Cost-effectiveness of Haemophilus Influenzae Type B Conjugate Vaccine and Pneumococcal Conjugate Vaccine in Somalia.

Science.gov (United States)

Gargano, Lisa M; Hajjeh, Rana; Cookson, Susan T

2015-08-01

Pneumonia is a leading cause of death among children less than five years old during humanitarian emergencies. Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae are the leading causes of bacterial pneumonia. Vaccines for both of these pathogens are available to prevent pneumonia. Problem This study describes an economic analysis from a publicly funded health care system perspective performed on a birth cohort in Somalia, a country that has experienced a protracted humanitarian emergency. An impact and cost-effectiveness analysis was performed comparing: no vaccine, Hib vaccine only, pneumococcal conjugate vaccine 10 (PCV10) only, and both together administered through supplemental immunization activities (SIAs). The main summary measure was the incremental cost per disability-adjusted life-years (DALYs) averted. One-way sensitivity analysis was conducted for uncertainty in parameter values. Each SIA would avert a substantial number of cases and deaths. Compared with no vaccine, the DALYs averted by two SIAs for two doses of Hib vaccine was US $202.93 (lower and upper limits: $121.80-$623.52), two doses of PCV10 was US $161.51 ($107.24-$227.21), and two doses of both vaccines was US $152.42 ($101.20-$214.42). Variables that influenced the cost-effectiveness for each strategy most substantially were vaccine effectiveness, case fatality rates (CFRs), and disease burden. The World Health Organization (WHO) defines a cost-effective intervention as costing one to three times the per capita gross domestic product (GDP; in 2011, for Somalia=US $112). Based on the presented model, Hib vaccine alone, PCV10 alone, or Hib vaccine and PCV10 given together in SIAs are cost-effective interventions in Somalia. The WHO/Strategic Advisory Group of Experts decision-making factors for vaccine deployment appear to have all been met: the disease burden is large, the vaccine-related risk is low, prevention in this setting is more feasible than treatment, the vaccine

Predictors of administration and attitudes about pneumococcal, Haemophilus influenzae type b and rotavirus vaccines among pediatricians in India: a national survey.

Science.gov (United States)

Gargano, Lisa M; Thacker, Naveen; Choudhury, Panna; Weiss, Paul S; Pazol, Karen; Bahl, Sunil; Jafari, Hamid S; Arora, Manisha; Orenstein, Walter A; Hughes, James M; Omer, Saad B

2012-05-21

According to the World Health Organization in 2008, pneumonia accounted for 20% of deaths and diarrheal diseases accounted for 13% of deaths among children under 5 in India. Vaccines are available for Streptococcus pneumoniae (pneumococcal conjugate vaccine (PCV)), Haemophilus influenzae type b (Hib vaccine), and rotavirus. Barriers to including these vaccines in routine immunization schedule in India include potential negative impacts on fragile existing immunization programs and cost. Pediatricians who are members of the Indian Academy of Pediatrics (IAP) are important stakeholders for vaccine delivery and maintaining public confidence in vaccines. A random sample of 785 pediatricians belonging to IAP was selected for the survey conducted from June 2009 to June 2010. Descriptive analyses using sampling weights were performed to evaluate the distributions of variables assessing vaccine-related attitudes and behaviors among pediatricians. Logistic regression was used to assess factors associated with routine vaccine use. The majority of pediatricians reported administering PCV (85.6%), Hib (95.9%), and rotavirus (80.2%) vaccine selectively or routinely. Pediatricians who had high perceived disease susceptibility were 2.42 times more likely to report routine administration of Hib vaccine (OR 2.42, 95% CI 1.24, 4.74). Pediatricians who had high perceived Hib vaccine efficacy were 4.74 times more likely to administer Hib vaccine routinely (OR 4.74, 95% CI 2.09, 10.74). Perceptions of disease susceptibility and severity or of vaccine safety and efficacy were not associated with routine administration of PCV or rotavirus vaccine. Understanding predictors of routine use of a new vaccine could help focus interventions to improve the routine use of other vaccines. The importance of perceived susceptibility to and severity of diseases caused by S. pneumoniae, Hib, and rotavirus and perceived efficacy and safety of the vaccines by pediatricians presents an opportunity to

Surveillance of adamantane resistance among influenza A H3 viruses isolated in Argentina between 2001 and 2007 Vigilancia de la resistencia a los adamantanos entre los virus influenza A H3 aislados en Argentina entre 2001 y 2007

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A. Pontoriero

2008-09-01

Full Text Available A dramatic rise in the frequency of resistance to adamantane drugs by influenza A H3 viruses, associated with a single amino acid replacement in the viral matrix M2 protein, has occurred in multiple countries worldwide in recent years. We investigated the frequency of adamantane-resistant influenza A H3 viruses in Argentina during the period 2001- 2007. We used reverse transcription followed by polymerase chain reaction. The obtained products were sequenced for the detection of mutations of the M2 gene relevant to the resistance phenotypes. The HA1 sequences of the sensitive and resistant strains were also analyzed to clarify whether they had any relevance to the resistant mutations. Twenty out of 55 (36% strains were identified with the resistance-conferring substitution at amino acid 31 (Serine 31 Asparagine. No resistant viruses were detected between 2001 and 2005. All strains isolated in 2006 and four out of five isolates from 2007 were resistant. None of the patients had received previous treatment with amantadine and/or rimantadine. The HA1 analysis showed that there were only two changes (Serine193 Phenylalanine and Aspartic acid 225 Asparagine present in the strains with the M2 substitution at position 31. Our data indicate that since 2006 there has been a significant increase of adamantane-resistant influenza A H3 viruses, which raises concern over the spread of these viruses in Argentina.En los últimos años, se ha detectado un aumento de virus influenza A H3 resistentes a los adamantanos en distintos países, asociados mayoritariamente con el reemplazo de un único aminoácido de la proteína matriz M2. Se investigó la frecuencia de virus influenza A H3 resistentes a los adamantanos en Argentina entre 2001 y 2007. Se utilizó la transcripción reversa seguida de la reacción en cadena de la polimerasa y de la técnica de secuencia directa para la detección de mutaciones en el gen que codifica para la proteína M2, relevantes para

A Review of the Antiviral Susceptibility of Human and Avian Influenza Viruses over the Last Decade

Science.gov (United States)

Oh, Ding Yuan; Hurt, Aeron C.

2014-01-01

Antivirals play an important role in the prevention and treatment of influenza infections, particularly in high-risk or severely ill patients. Two classes of influenza antivirals have been available in many countries over the last decade (2004–2013), the adamantanes and the neuraminidase inhibitors (NAIs). During this period, widespread adamantane resistance has developed in circulating influenza viruses rendering these drugs useless, resulting in the reliance on the most widely available NAI, oseltamivir. However, the emergence of oseltamivir-resistant seasonal A(H1N1) viruses in 2008 demonstrated that NAI-resistant viruses could also emerge and spread globally in a similar manner to that seen for adamantane-resistant viruses. Previously, it was believed that NAI-resistant viruses had compromised replication and/or transmission. Fortunately, in 2013, the majority of circulating human influenza viruses remain sensitive to all of the NAIs, but significant work by our laboratory and others is now underway to understand what enables NAI-resistant viruses to retain the capacity to replicate and transmit. In this review, we describe how the susceptibility of circulating human and avian influenza viruses has changed over the last ten years and describe some research studies that aim to understand how NAI-resistant human and avian influenza viruses may emerge in the future. PMID:24800107

Multidrug resistant 2009 A/H1N1 influenza clinical isolate with a neuraminidase I223R mutation retains its virulence and transmissibility in ferrets.

Directory of Open Access Journals (Sweden)

Erhard van der Vries

2011-09-01

Full Text Available Only two classes of antiviral drugs, neuraminidase inhibitors and adamantanes, are approved for prophylaxis and therapy against influenza virus infections. A major concern is that influenza virus becomes resistant to these antiviral drugs and spreads in the human population. The 2009 pandemic A/H1N1 influenza virus is naturally resistant to adamantanes. Recently a novel neuraminidase I223R mutation was identified in an A/H1N1 virus showing cross-resistance to the neuraminidase inhibitors oseltamivir, zanamivir and peramivir. However, the ability of this virus to cause disease and spread in the human population is unknown. Therefore, this clinical isolate (NL/2631-R223 was compared with a well-characterized reference virus (NL/602. In vitro experiments showed that NL/2631-I223R replicated as well as NL/602 in MDCK cells. In a ferret pathogenesis model, body weight loss was similar in animals inoculated with NL/2631-R223 or NL/602. In addition, pulmonary lesions were similar at day 4 post inoculation. However, at day 7 post inoculation, NL/2631-R223 caused milder pulmonary lesions and degree of alveolitis than NL/602. This indicated that the mutant virus was less pathogenic. Both NL/2631-R223 and a recombinant virus with a single I223R change (recNL/602-I223R, transmitted among ferrets by aerosols, despite observed attenuation of recNL/602-I223R in vitro. In conclusion, the I223R mutated virus isolate has comparable replicative ability and transmissibility, but lower pathogenicity than the reference virus based on these in vivo studies. This implies that the 2009 pandemic influenza A/H1N1 virus subtype with an isoleucine to arginine change at position 223 in the neuraminidase has the potential to spread in the human population. It is important to be vigilant for this mutation in influenza surveillance and to continue efforts to increase the arsenal of antiviral drugs to combat influenza.

Investigation of genome sequences within the family Pasteurellaceae

DEFF Research Database (Denmark)

Angen, Øystein; Ussery, David

Introduction The bacterial genome sequences are now available for an increasing number of strains within the family Pasteurellaceae. At present, 24 Pasteurellaceae genomes are publicly available through internet databases, and another 40 genomes are being sequenced. This investigation will describe...... the core genome for both the family Pasteurellaceae and for the species Haemophilus influenzae. Methods Twenty genome sequences from the following species were included: Haemophilus influenzae (11 strains), Haemophilus ducreyi (1 strain), Histophilus somni (2 strains), Haemophilus parasuis (1 strain......), Actinobacillus pleuropneumoniae (2 strains), Actinobacillus succinogenes (1 strain), Mannheimia succiniciproducens (1 strain), and Pasteurella multocida (1 strain). The predicted proteins for each genome were BLASTed against each other, and a set of conserved core gene families was determined as described...

Host-pathogen interplay of Haemophilus ducreyi.

Science.gov (United States)

Janowicz, Diane M; Li, Wei; Bauer, Margaret E

2010-02-01

Haemophilus ducreyi, the causative agent of the sexually transmitted infection chancroid, is primarily a pathogen of human skin. During infection, H. ducreyi thrives extracellularly in a milieu of professional phagocytes and other antibacterial components of the innate and adaptive immune responses. This review summarizes our understanding of the interplay between this pathogen and its host that leads to development and persistence of disease. H. ducreyi expresses key virulence mechanisms to resist host defenses. The secreted LspA proteins are tyrosine-phosphorylated by host kinases, which may contribute to their antiphagocytic effector function. The serum resistance and adherence functions of DsrA map to separate domains of this multifunctional virulence factor. An influx transporter protects H. ducreyi from killing by the antimicrobial peptide LL37. Regulatory genes have been identified that may coordinate virulence factor expression during disease. Dendritic cells and natural killer cells respond to H. ducreyi and may be involved in determining the differential outcomes of infection observed in humans. A human model of H. ducreyi infection has provided insights into virulence mechanisms that allow this human-specific pathogen to survive immune pressures. Components of the human innate immune system may also determine the ultimate fate of H. ducreyi infection by driving either clearance of the organism or an ineffective response that allows disease progression.

Organisms cultured and resistance patterns seen in a secondary ...

African Journals Online (AJOL)

21% for piperacillin-tazobactam, 2% for ertapenem and. 19% for meropenem). When looking at individual species, it was noted that K. pneumoniae had high resistance to ampicillin (97%), moderate resistance to co-amoxiclav and ciprofloxacin ...

Drug susceptibility of influenza A/H3N2 strains co-circulating during 2009 influenza pandemic: first report from Mumbai.

Science.gov (United States)

Gohil, Devanshi J; Kothari, Sweta T; Shinde, Pramod S; Chintakrindi, Anand S; Meharunkar, Rhuta; Warke, Rajas V; Kanyalkar, Meena A; Chowdhary, Abhay S; Deshmukh, Ranjana A

2015-01-01

From its first instance in 1977, resistance to amantadine, a matrix (M2) inhibitor has been increasing among influenza A/H3N2, thus propelling the use of oseltamivir, a neuraminidase (NA) inhibitor as a next line drug. Information on drug susceptibility to amantadine and neuraminidase inhibitors for influenza A/H3N2 viruses in India is limited with no published data from Mumbai. This study aimed at examining the sensitivity to M2 and NA inhibitors of influenza A/H3N2 strains isolated from 2009 to 2011 in Mumbai. Nasopharyngeal swabs positive for influenza A/H3N2 virus were inoculated on Madin-Darby canine kidney (MDCK) cell line for virus isolation. Molecular analysis of NA and M2 genes was used to detect known mutations contributing to resistance. Resistance to neuraminidase was assayed using a commercially available chemiluminescence based NA-Star assay kit. Genotypically, all isolates were observed to harbor mutations known to confer resistance to amantadine. However, no know mutations conferring resistance to NA inhibitors were detected. The mean IC50 value for oseltamivir was 0.25 nM. One strain with reduced susceptibility to the neuraminidase inhibitor (IC₅₀=4.08 nM) was isolated from a patient who had received oseltamivir treatment. Phylogenetic analysis postulate the emergence of amantadine resistance in Mumbai may be due to genetic reassortment with the strains circulating in Asia and North America. Surveillance of drug susceptibility helped us to identify an isolate with reduced sensitivity to oseltamivir. Therefore, we infer that such surveillance would help in understanding possible trends underlying the emergence of resistant variants in humans. Copyright © 2014 Elsevier B.V. All rights reserved.

Tentative minimum inhibitory concentration and zone diameter breakpoints for moxifloxacin using BSAC criteria.

Science.gov (United States)

Andrews, J M; Ashby, J P; Jevons, G M; Wise, R

1999-12-01

Tentative MIC and zone diameter breakpoints were determined for moxifloxacin using BSAC criteria. An MIC breakpoint of or = 20 mm for Enterobacteriaceae and staphylococci, 18 mm for the respiratory pathogens (Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis) and 15 mm for enterococci. For Pseudomonas aeruginosa with a 5 microg disc, three bands are suggested for interpretation, that of > or = 25 mm (sensitive), 18-24 mm (intermediate) and < or = 17 mm (resistant).

Streptococcus pneumoniae Coinfection Is Correlated with the Severity of H1N1 Pandemic Influenza

Science.gov (United States)

Cisterna, Daniel; Savji, Nazir; Bussetti, Ana Valeria; Kapoor, Vishal; Hui, Jeffrey; Tokarz, Rafal; Briese, Thomas; Baumeister, Elsa; Lipkin, W. Ian

2009-01-01

Background Initial reports in May 2009 of the novel influenza strain H1N1pdm estimated a case fatality rate (CFR) of 0.6%, similar to that of seasonal influenza. In July 2009, however, Argentina reported 3056 cases with 137 deaths, representing a CFR of 4.5%. Potential explanations for increased CFR included virus reassortment or genetic drift, or infection of a more vulnerable population. Virus genomic sequencing of 26 Argentinian samples representing both severe and mild disease indicated no evidence of reassortment, mutations associated with resistance to antiviral drugs, or genetic drift that might contribute to virulence. Furthermore, no evidence was found for increased frequency of risk factors for H1N1pdm disease. Methods/Principal Findings We examined nasopharyngeal swab samples (NPS) from 199 cases of H1N1pdm infection from Argentina with MassTag PCR, testing for 33 additional microbial agents. The study population consisted of 199 H1N1pdm-infected subjects sampled between 23 June and 4 July 2009. Thirty-nine had severe disease defined as death (n = 20) or hospitalization (n = 19); 160 had mild disease. At least one additional agent of potential pathogenic importance was identified in 152 samples (76%), including Streptococcus pneumoniae (n = 62); Haemophilus influenzae (n = 104); human respiratory syncytial virus A (n = 11) and B (n = 1); human rhinovirus A (n = 1) and B (n = 4); human coronaviruses 229E (n = 1) and OC43 (n = 2); Klebsiella pneumoniae (n = 2); Acinetobacter baumannii (n = 2); Serratia marcescens (n = 1); and Staphylococcus aureus (n = 35) and methicillin-resistant S. aureus (MRSA, n = 6). The presence of S. pneumoniae was strongly correlated with severe disease. S. pneumoniae was present in 56.4% of severe cases versus 25% of mild cases; more than one-third of H1N1pdm NPS with S. pneumoniae were from subjects with severe disease (22 of 62 S. pneumoniae-positive NPS, p = 0

Antimicrobial activity of innate immune molecules against Streptococcus pneumoniae, Moraxella catarrhalis and nontypeable Haemophilus influenzae

Directory of Open Access Journals (Sweden)

Teufert Karen

2004-05-01

Full Text Available Abstract Background Despite its direct connection to the nasopharynx which harbors otitis media pathogens as part of its normal flora, the middle ear cavity is kept free of these bacteria by as yet unknown mechanisms. Respiratory mucosal epithelia, including those of the middle ear and eustachian tube, secrete antimicrobial effectors including lysozyme, lactoferrin and β defensins-1 and -2. To elucidate the role of these innate immune molecules in the normal defense and maintenance of sterility of respiratory mucosa such as that of the middle ear, we assessed their effect on the respiratory pathogens nontypeable Haemophilus influenzae (NTHi 12, Moraxella catarrhalis 035E, and Streptococcus pneumoniae 3, and 6B. Methods Two assay methods, the radial assay and the liquid broth assay, were employed for testing the antimicrobial activity of the molecules. This was done in order to minimize the possibility that the observed effects were artifacts of any single assay system employed. Also, transmission electron microscopy (TEM was employed to evaluate the effect of antimicrobial innate immune molecules on OM pathogens. For the statistical analysis of the data, Student's t-test was performed. Results Results of the radial diffusion assay showed that β defensin-2 was active against all four OM pathogens tested, while treatment with β defensin-1 appeared to only affect M. catarrhalis. The radial assay results also showed that lysozyme was quite effective against S. pneumoniae 3 and 6B and was partially bacteriostatic/bactericidal against M. catarrhalis. Lysozyme however, appeared not to affect the growth of NTHi. Thus, lysozyme seems to have a more pronounced impact on the growth of the Gram-positive S. pneumoniae as compared to that of Gram-negative pathogens. Lactoferrin on the other hand, enhanced the growth of the bacteria tested. The results of the radial assays were confirmed using liquid broth assays for antimicrobial activity, and showed that

Budget impact analysis of vaccination against Haemophilus influenzae type b as a part of a Pentavalent vaccine in the childhood immunization schedule of Iran.