Khan, Gulfaraz; Ahmed, Waqar; Philip, Pretty S; Ali, Mahmoud H; Adem, Abdu
Epstein-Barr virus (EBV) is an oncogenic virus implicated in the pathogenesis of several human malignancies. However, due to the lack of a suitable animal model, a number of fundamental questions pertaining to the biology of EBV remain poorly understood. Here, we explore the potential of rabbits as a model for EBV infection and investigate the impact of immunosuppression on viral proliferation and gene expression. Six healthy New Zealand white rabbits were inoculated intravenously with EBV and blood samples collected prior to infection and for 7 weeks post-infection. Three weeks after the last blood collection, animals were immunosuppressed with daily intramuscular injections of cyclosporin A at doses of 20 mg/kg for 15 days and blood collected twice a week from each rabbit. The animals were subsequently sacrificed and tissues from all major organs were collected for subsequent analysis. Following intravenous inoculation, all 6 rabbits seroconverted with raised IgG and IgM titres to EBV, but viral DNA in peripheral blood mononuclear cells (PBMCs) could only be detected intermittently. Following immunosuppression however, EBV DNA could be readily detected in PBMCs from all 4 rabbits that survived the treatment. Quantitative PCR indicated an increase in EBV viral load in PBMCs as the duration of immunosuppression increased. At autopsy, splenomegaly was seen in 3/4 rabbits, but spleens from all 4 rabbit were EBV PCR positive. EBER-in situ hybridization and immunoshistochemistry revealed the presence of a large number of EBER-positive and LMP-1 positive lymphoblasts in the spleens of 3/4 rabbits. To a lesser extent, EBER-positive cells were also seen in the portal tract regions of the liver of these rabbits. Western blotting indicated that EBNA-1 and EBNA-2 were also expressed in the liver and spleen of infected animals. EBV can infect healthy rabbits and the infected cells proliferate when the animals are immunocompromised. The infected cells expressed several EBV
Plantinga, T.S.; Johnson, M.D.; Scott, W.K.; Joosten, L.A.B.; Meer, J.W. van der; Perfect, J.R.; Kullberg, B.J.; Netea, M.G.
Infections with Candida spp. have different manifestations in humans, ranging from mucosal to bloodstream and deep-seated disseminated infections. Immunocompromised patients have increased susceptibility to these types of infections, due to reduced capacity to elicit effective innate or adaptive
Immune Disorders; Chronic Granulomatous Disease; Genetic Immunological Deficiencies; Hyperimmunoglobulin-E Recurrent Infection Syndrome; Recurrent Infections; Unknown Immune Deficiency; GATA2 Deficiency (MonoMAC); Nontuberculous Mycobacterial Infections; Hyper IgE (Job s) Syndrome; Leukocyte Adhesion Deficiency; Susceptibility to Disseminated Infections; Primary Immune Deficiency Disease (PIDD)
Demuth Donald R
Full Text Available Abstract Active smokers and those exposed to secondhand smoke are at increased risk of bacterial infection. Tobacco smoke exposure increases susceptibility to respiratory tract infections, including tuberculosis, pneumonia and Legionnaires disease; bacterial vaginosis and sexually transmitted diseases, such as chlamydia and gonorrhoea; Helicobacter pylori infection; periodontitis; meningitis; otitis media; and post-surgical and nosocomial infections. Tobacco smoke compromises the anti-bacterial function of leukocytes, including neutrophils, monocytes, T cells and B cells, providing a mechanistic explanation for increased infection risk. Further epidemiological, clinical and mechanistic research into this important area is warranted.
Chapman, J L; Nichols, D K; Martinez, M J; Raymond, J W
Smallpox was one of the most devastating diseases known to humanity. Although smallpox was eradicated through a historically successful vaccination campaign, there is concern in the global community that either Variola virus (VARV), the causative agent of smallpox, or another species of Orthopoxvirus could be used as agents of bioterrorism. Therefore, development of countermeasures to Orthopoxvirus infection is a crucial focus in biodefense research, and these efforts rely on the use of various animal models. Smallpox typically presented as a generalized pustular rash with 30 to 40% mortality, and although smallpox-like syndromes can be induced in cynomolgus macaques with VARV, research with this virus is highly restricted; therefore, animal models with other orthopoxviruses have been investigated. Monkeypox virus causes a generalized vesiculopustular rash in rhesus and cynomolgus macaques and induces fatal systemic disease in several rodent species. Ectromelia virus has been extensively studied in mice as a model of orthopoxviral infection in its natural host. Intranasal inoculation of mice with some strains of vaccinia virus produces fatal bronchopneumonia, as does aerosol or intranasal inoculation of mice with cowpox virus. Rabbitpox virus causes pneumonia and fatal systemic infections in rabbits and can be naturally transmitted between rabbits by an aerosol route similar to that of VARV in humans. No single animal model recapitulates all known aspects of human Orthopoxvirus infections, and each model has its advantages and disadvantages. This article provides a brief review of the Orthopoxvirus diseases of humans and the key pathologic features of animal models of Orthopoxvirus infections.
Full Text Available Experimental infections with three different species of Trichinella in nutria in order to evaluate the susceptibility and the role of these rodents in the spreading of parasitosis in nature were carried out. The nutria is present in many italian wet areas and its distribution is expanding. The nutria meat is utilized as food in different countries and is retained responsible for trichinellosis in man. Two groups of ten animals were infected per os with 500 and 5,000 (n. 10 infective larvae of T. britovi; an additional study was arranged with two groups of animals infected with 5,000 larvae of T. spiralis and T. pseudospiralis, respectively. After 45 days, all animals were slaughtered and samples of different muscles were processed by standard artificial digestion and by routine histological methods. Serological investigations (specific IgG have been carried out on sera samples by employing a monoclonal blocking ELISA. The animals showed a significant susceptibility to the infection with all species of tested Trichinella and immunological reactivity. Data obtained are discussed.
Stuart D Dowall
Full Text Available Zika virus (ZIKV is a mosquito-borne pathogen which has recently spread beyond Africa and into Pacific and South American regions. Despite first being detected in 1947, very little information is known about the virus, and its spread has been associated with increases in Guillain-Barre syndrome and microcephaly. There are currently no known vaccines or antivirals against ZIKV infection. Progress in assessing interventions will require the development of animal models to test efficacies; however, there are only limited reports on in vivo studies. The only susceptible murine models have involved intracerebral inoculations or juvenile animals, which do not replicate natural infection. Our report has studied the effect of ZIKV infection in type-I interferon receptor deficient (A129 mice and the parent strain (129Sv/Ev after subcutaneous challenge in the lower leg to mimic a mosquito bite. A129 mice developed severe symptoms with widespread viral RNA detection in the blood, brain, spleen, liver and ovaries. Histological changes were also striking in these animals. 129Sv/Ev mice developed no clinical symptoms or histological changes, despite viral RNA being detectable in the blood, spleen and ovaries, albeit at lower levels than those seen in A129 mice. Our results identify A129 mice as being highly susceptible to ZIKV and thus A129 mice represent a suitable, and urgently required, small animal model for the testing of vaccines and antivirals.
Dowall, Stuart D; Graham, Victoria A; Rayner, Emma; Atkinson, Barry; Hall, Graham; Watson, Robert J; Bosworth, Andrew; Bonney, Laura C; Kitchen, Samantha; Hewson, Roger
Zika virus (ZIKV) is a mosquito-borne pathogen which has recently spread beyond Africa and into Pacific and South American regions. Despite first being detected in 1947, very little information is known about the virus, and its spread has been associated with increases in Guillain-Barre syndrome and microcephaly. There are currently no known vaccines or antivirals against ZIKV infection. Progress in assessing interventions will require the development of animal models to test efficacies; however, there are only limited reports on in vivo studies. The only susceptible murine models have involved intracerebral inoculations or juvenile animals, which do not replicate natural infection. Our report has studied the effect of ZIKV infection in type-I interferon receptor deficient (A129) mice and the parent strain (129Sv/Ev) after subcutaneous challenge in the lower leg to mimic a mosquito bite. A129 mice developed severe symptoms with widespread viral RNA detection in the blood, brain, spleen, liver and ovaries. Histological changes were also striking in these animals. 129Sv/Ev mice developed no clinical symptoms or histological changes, despite viral RNA being detectable in the blood, spleen and ovaries, albeit at lower levels than those seen in A129 mice. Our results identify A129 mice as being highly susceptible to ZIKV and thus A129 mice represent a suitable, and urgently required, small animal model for the testing of vaccines and antivirals.
Full Text Available Increased susceptibility to co-infection with enteric Gram-negative bacteria, particularly non-typhoidal Salmonella, is reported in malaria and Oroya fever (Bartonella bacilliformis infection, and can lead to increased mortality. Accumulating epidemiological evidence indicates a causal association with risk of bacterial co-infection, rather than just co-incidence of common risk factors. Both malaria and Oroya fever are characterised by hemolysis, and observations in humans and animal models suggest that hemolysis causes the susceptibility to bacterial co-infection. Evidence from animal models implicates hemolysis in the impairment of a variety of host defence mechanisms, including macrophage dysfunction, neutrophil dysfunction and impairment of adaptive immune responses. One mechanism supported by evidence from animal models and human data, is the induction of heme oxygenase-1 in bone marrow, which impairs the ability of developing neutrophils to mount a competent oxidative burst. As a result, dysfunctional neutrophils become a new niche for replication of intracellular bacteria. Here we critically appraise and summarize the key evidence for mechanisms which may contribute to these very specific combinations of co-infections, and propose interventions to ameliorate this risk.
Shao, Jinlong; Kolwijck, Eva; Jansen, John A; Yang, Fang; Walboomers, X Frank
This review focuses on the construction of animal models for percutaneous-device-related infections, and specifically the role of inoculation of bacteria in such models. Infections around percutaneous devices, such as catheters, dental implants and limb prostheses, are a recurrent and persistent clinical problem. To promote the research on this clinical problem, the establishment of a reliable and validated animal model would be of keen interest. In this review, literature related to percutaneous devices was evaluated, and particular attention was paid to studies involving the use of bacteria. The design of percutaneous devices, susceptibility of various animal species, bacterial strains, amounts of bacteria, method of inoculation and methods for subsequent evaluation of the infection are discussed in detail. Given that an ideal animal model for study of percutaneous-device-related infection is still not existent, this article presents the basis for the construction of such a standardized animal model for percutaneous-device-related infection studies. The inoculation of bacteria is critical to obtain an animal model for standardized studies for percutaneous-device-related infections. Copyright © 2017. Published by Elsevier B.V.
Nejsum, Peter; Thamsborg, Stig Milan; Göring, H. H.
Intestinal helminth infections are causing health and welfare problems in both human and animal populations. A family, in which susceptibility towards Ascaris (large round worm) and Trichuris (whipworm) infections are segregating, was constructed. Our data demonstrate that genetic components ar...
Elias, D; Akuffo, H; Thors, C; Pawlowski, A; Britton, S
The incidence of mycobacterial diseases is high and the efficacy of Bacillus Calmette Guerin (BCG) is low in most areas of the world where chronic worm infections are common. However, if and how concurrent worm infections could affect immunity to mycobacterial infections has not been elucidated. In this study we investigated whether infection of mice with Schistosoma mansoni could affect the ability of the animals to control Mycobacterium bovis BCG infection and the immune response to mycobacterial antigens. BALB/c mice subclinically infected with S. mansoni were challenged with M. bovis BCG via the intravenous route. The ability of the animals to contain the replication of M. bovis BCG in their organs, lung pathology as well as the in vitro mycobacterial and worm antigen induced immune responses were evaluated. The results showed that S. mansoni coinfected mice had significantly higher levels of BCG bacilli in their organs and sustained greater lung pathology compared to Schistosoma uninfected controls. Moreover, Schistosoma infected mice show depressed mycobacterial antigen specific Th1 type responses. This is an indication that chronic worm infection could affect resistance/susceptibility to mycobacterial infections by impairing mycobacteria antigen specific Th1 type responses. This finding is potentially important in the control of TB in helminth endemic parts of the world.
León, Cielo M; Montilla, Marleny; Vanegas, Ricardo; Castillo, Maria; Parra, Edgar; Ramírez, Juan David
Chagas disease is a complex zoonosis that affects around 8 million people worldwide. This pathology is caused by Trypanosoma cruzi, a kinetoplastid parasite that shows tremendous genetic diversity evinced in six distinct Discrete Typing Units (TcI-TcVI) including a recent genotype named as TcBat and associated with anthropogenic bats. TcI presents a broad geographical distribution and has been associated with chronic cardiomyopathy. Recent phylogenetic studies suggest the existence of two genotypes (Domestic (TcIDom) and sylvatic TcI) within TcI. The understanding of the course of the infection in different mouse models by these two genotypes is not yet known. Therefore, we infected 126 animals (ICR-CD1, National Institute of Health (NIH) and Balb/c) with two TcIDom strains and one sylvatic strain for a follow-up period of 60 days. We quantified the parasitaemia, immune response and histopathology observing that the maximum day of parasitaemia was achieved at day 21 post-infection. Domestic strains showed higher parasitaemia than the sylvatic strain in the three mouse models; however in the survival curves Balb/c mice were less susceptible to infection compared with NIH and ICR-CD1. Our results suggest that the genetic background plays a fundamental role in the natural history of the infection and the sympatric TcI genotypes have relevant implications in disease pathogenesis.
Feng, Lynna C; Chouinard, Philippe A; Howell, Tiffani J; Bennett, Pauleen C
In humans, geometrical illusions are thought to reflect mechanisms that are usually helpful for seeing the world in a predictable manner. These mechanisms deceive us given the right set of circumstances, correcting visual input where a correction is not necessary. Investigations of non-human animals' susceptibility to geometrical illusions have yielded contradictory results, suggesting that the underlying mechanisms with which animals see the world may differ across species. In this review, we first collate studies showing that different species are susceptible to specific illusions in the same or reverse direction as humans. Based on a careful assessment of these findings, we then propose several ecological and anatomical factors that may affect how a species perceives illusory stimuli. We also consider the usefulness of this information for determining whether sight in different species might be more similar to human sight, being influenced by contextual information, or to how machines process and transmit information as programmed. Future testing in animals could provide new theoretical insights by focusing on establishing dissociations between stimuli that may or may not alter perception in a particular species. This information could improve our understanding of the mechanisms behind illusions, but also provide insight into how sight is subjectively experienced by different animals, and the degree to which vision is innate versus acquired, which is difficult to examine in humans.
Full Text Available Bordetella bronchiseptica causes infections of the respiratory tract in swine and other mammals and is a precursor for secondary infections with Pasteurella multocida. Treatment of B. bronchiseptica infections is conducted primarily with antimicrobial agents. Therefore it is essential to get an overview of the susceptibility status of these bacteria. The aim of this study was to comparatively analyse broth microdilution susceptibility testing according to CLSI recommendations with an incubation time of 16 to 20 hours and a longer incubation time of 24 hours, as recently proposed to obtain more homogenous MICs. Susceptibility testing against a panel of 22 antimicrobial agents and two fixed combinations was performed with 107 porcine isolates from different farms and regions in Germany and 43 isolates obtained from companion animals in Germany and other European countries. Isolates with increased MICs were investigated by PCR assays for the presence of resistance genes. For ampicillin, all 107 porcine isolates were classified as resistant, whereas only a single isolate was resistant to florfenicol. All isolates obtained from companion animals showed elevated MICs for β-lactam antibiotics and demonstrated an overall low susceptibility to cephalosporines. Extension of the incubation time resulted in 1-2 dilution steps higher MIC50 values of porcine isolates for seven antimicrobial agents tested, while isolates from companion animals exhibited twofold higher MIC50/90 values only for tetracycline and cefotaxime. For three antimicrobial agents, lower MIC50 and MIC90 values were detected for both, porcine and companion animal isolates. Among the 150 isolates tested, the resistance genes blaBOR-1 (n = 147, blaOXA-2, (n = 4, strA and strB (n = 17, sul1 (n = 10, sul2 (n = 73, dfrA7 (n = 3 and tet(A (n = 8 were detected and a plasmid localisation was identified for several of the resistance genes.
Visvabharathy, Lavanya; Xayarath, Bobbi; Weinberg, Guy; Shilling, Rebecca A.; Freitag, Nancy E.
Anesthetics are known to modulate host immune responses, but separating the variables of surgery from anesthesia when analyzing hospital acquired infections is often difficult. Here, the bacterial pathogen Listeria monocytogenes (Lm) was used to assess the impact of the common anesthetic propofol on host susceptibility to infection. Brief sedation of mice with physiologically relevant concentrations of propofol increased bacterial burdens in target organs by more than 10,000-fold relative to infected control animals. The adverse effects of propofol sedation on immune clearance of Lm persisted after recovery from sedation, as animals given the drug remained susceptible to infection for days following anesthesia. In contrast to propofol, sedation with alternative anesthetics such as ketamine/xylazine or pentobarbital did not increase susceptibility to systemic Lm infection. Propofol altered systemic cytokine and chemokine expression during infection, and prevented effective bacterial clearance by inhibiting the recruitment and/or activity of immune effector cells at sites of infection. Propofol exposure induced a marked reduction in marginal zone macrophages in the spleens of Lm infected mice, resulting in bacterial dissemination into deep tissue. Propofol also significantly increased mouse kidney abscess formation following infection with the common nosocomial pathogen Staphylococcus aureus. Taken together, these data indicate that even brief exposure to propofol severely compromises host resistance to microbial infection for days after recovery from sedation. PMID:26381144
Li, Wen-wen; Yan, Zu-wei; Dai, Gan
To isolate bacteria, mycoplasma and chlamydia from the urogenital tract, and to determine their antibiotic susceptibility. Bacteria, mycoplasma and chlamydia were isolated from the urogenital tract secretion by artifical culture, and their antibiotic susceptibility was detected by disk diffusion. The common microorganisms were S. epidermidis and corynebacberium, and the minority microorganisms were G- bacteria or E. coli. Bacteria were susceptible to amikacin, cephazolin V, rifampin, gentamycin, and docycyclin. S. epidermidis and corynebacterium are important pathogens of the urogenital tract infection. Disk susceptibility test can be used to screen the susceptible antibiotic.
Eva Harris; Simona Zompi
The development of animal models of dengue virus (DENV) infection and disease has been challenging, as epidemic DENV does not naturally infect non-human species. Non-human primates (NHPs) can sustain viral replication in relevant cell types and develop a robust immune response, but they do not develop overt disease. In contrast, certain immunodeficient mouse models infected with mouse-adapted DENV strains show signs of severe disease similar to the ‘vascular-leak’ syndrome seen in severe deng...
Yáñez Antonio; Martínez-Ramos Azucena; Calixto Teresa; González-Matus Francisco Javier; Rivera-Tapia José Antonio; Giono Silvia; Gil Constantino; Cedillo Lilia
Abstract Background Mycoplasma fermentans has been associated with respiratory, genitourinary tract infections and rheumatoid diseases but its role as pathogen is controversial. The purpose of this study was to probe that Mycoplasma fermentans is able to produce respiratory tract infection and migrate to several organs on an experimental infection model in hamsters. One hundred and twenty six hamsters were divided in six groups (A-F) of 21 hamsters each. Animals of groups A, B, C were intratr...
Cator, E.A.; Van Mieghem, P.
Since mean-field approximations for susceptible-infected-susceptible (SIS) epidemics do not always predict the correct scaling of the epidemic threshold of the SIS metastable regime, we propose two novel approaches: (a) an ?-SIS generalized model and (b) a modified SIS model that prevents the
Antibiotic susceptibility of organisms causing urinary tract infection in patients presenting at Kenyatta National Hospital, Nairobi. ... encourage prudent use of antimicrobials. Objectives: To identify bacterial pathogens causing UTI and determine the association between the pathogens isolated from patients attending KNH.
Antonissen, Gunther; Martel, An; Pasmans, Frank; Ducatelle, Richard; Verbrugghe, Elin; Vandenbroucke, Virginie; Li, Shaoji; Haesebrouck, Freddy; Van Immerseel, Filip; Croubels, Siska
Contamination of food and feed with mycotoxins is a worldwide problem. At present, acute mycotoxicosis caused by high doses is rare in humans and animals. Ingestion of low to moderate amounts of Fusarium mycotoxins is common and generally does not result in obvious intoxication. However, these low amounts may impair intestinal health, immune function and/or pathogen fitness, resulting in altered host pathogen interactions and thus a different outcome of infection. This review summarizes the current state of knowledge about the impact of Fusarium mycotoxin exposure on human and animal host susceptibility to infectious diseases. On the one hand, exposure to deoxynivalenol and other Fusarium mycotoxins generally exacerbates infections with parasites, bacteria and viruses across a wide range of animal host species. Well-known examples include coccidiosis in poultry, salmonellosis in pigs and mice, colibacillosis in pigs, necrotic enteritis in poultry, enteric septicemia of catfish, swine respiratory disease, aspergillosis in poultry and rabbits, reovirus infection in mice and Porcine Reproductive and Respiratory Syndrome Virus infection in pigs. However, on the other hand, T-2 toxin has been shown to markedly decrease the colonization capacity of Salmonella in the pig intestine. Although the impact of the exposure of humans to Fusarium toxins on infectious diseases is less well known, extrapolation from animal models suggests possible exacerbation of, for instance, colibacillosis and salmonellosis in humans, as well. PMID:24476707
Petra C.F. Oyston
Full Text Available Plague is a zoonotic disease, normally circulating in rodent populations, transmitted to humans most commonly through the bite of an infected flea vector. Secondary infection of the lungs results in generation of infectious aerosols, which pose a significant hazard to close contacts. In enzootic areas, plague infections have been reported in owners and veterinarians who come into contact with infected pets. Dogs are relatively resistant, but can import infected fleas into the home. Cats are acutely susceptible, and can present a direct hazard to health. Reducing roaming and hunting behaviours, combined with flea control measures go some way to reducing the risk to humans. Various vaccine formulations have been developed which may be suitable to protect companion animals from contracting plague, and thus preventing onward transmission to man. Since transmission has resulted in a number of fatal cases of plague, the vaccination of domestic animals such as cats would seem a low cost strategy for reducing the risk of infection by this serious disease in enzootic regions.
The epidemic spreading has been studied for years by applying the mean-field approach in both homogeneous case, where each node may get infected by an infected neighbor with the same rate, and heterogeneous case, where the infection rates between different pairs of nodes are different. Researchers have discussed whether the mean-field approaches could accurately describe the epidemic spreading for the homogeneous cases but not for the heterogeneous cases. In this paper, we explore under what conditions the mean-field approach could perform well when the infection rates are heterogeneous. In particular, we employ the Susceptible-Infected-Susceptible (SIS) model and compare the average fraction of infected nodes in the metastable state obtained by the continuous-time simulation and the mean-field approximation. We concentrate on an individual-based mean-field approximation called the N-intertwined Mean Field Approximation (NIMFA), which is an advanced approach considered the underlying network topology. Moreove...
Full Text Available Primary infection with varicella zoster virus (VZV results in varicella (chickenpox followed by the establishment of latency in sensory ganglia. Declining T cell immunity due to aging or immune suppressive treatments can lead to VZV reactivation and the development of herpes zoster (HZ, shingles. HZ is often associated with significant morbidity and occasionally mortality in elderly and immune compromised patients. There are currently two FDA-approved vaccines for the prevention of VZV: Varivax® (for varicella and Zostavax® (for HZ. Both vaccines contain the live-attenuated Oka strain of VZV. Although highly immunogenic, a two-dose regimen is required to achieve a 99% seroconversion rate. Zostavax vaccination reduces the incidence of HZ by 51% within a 3-year period, but a significant reduction in vaccine-induced immunity is observed within the first year after vaccination. Developing more efficacious vaccines and therapeutics requires a better understanding of the host response to VZV. These studies have been hampered by the scarcity of animal models that recapitulate all aspects of VZV infections in humans. In this review, we describe different animal models of VZV infection as well as an alternative animal model that leverages the infection of Old World macaques with the highly related simian varicella virus (SVV and discuss their contributions to our understanding of pathogenesis and immunity during VZV infection.
Full Text Available Paracoccidioidomycosis (PCM is the most prevalent deep mycosis in Latin America and presents a wide spectrum of clinical manifestations. We established a genetically controlled murine model of PCM, where A/Sn mice develop an infection which mimics the benign disease (immune responses which favor cellular immunity and B10.A animals present the progressive disseminated form of PCM (preferential activation of B cells and impairment of cellular immune responses. To understand the immunoregulatory phenomena associated with resistance and susceptibility in experimental PCM, A/Sn and B10.A mice were studied regarding antigen-elicited secretion of monokines (TNF-a and TGF-ß and type-1 (IL-2 and IFN-g and type-2 (IL-4,5,10 cytokines. Total lymph node cells from resistant mice infected ip with P. brasiliensis produced early and sustained levels of IFN-g and IL-2; type-2 cytokines (IL-4 and IL-5 started to appear 8 weeks after infection. In contrast, susceptible mice produced low levels of IFN-g concomitant with significant levels of IL-5 and IL-10 early in the infection. In the chronic phase of the disease, susceptible animals presented a transitory secretion of IL-2, and IL-4. In the pulmonary infection IL-4, IL-5 and IL-10 were preferentially detected in the lung cells washings of susceptible animals. After in vitro challenge with fungal antigens, normal peritoneal macrophages from B10.A mice secreted high levels of TGF-ß and low levels of TNF-a. In contrast, macrophages from A/Sn animals released high levels of TNF-a associated with a small production of TGF-ß. The in vivo depletion of IFN-g not only abrogated the resistance of A/Sn mice but also diminished the relative resistance of B10.A animals. The in vivo depletion of IL-4 did not alter the disease outcome, whereas administration of rIL-12 significantly enhanced resistance in susceptible animals. Taken together, these results suggest that an early secretion of high levels of TNF-a and IFN
Miyaho, Rie Nakaoka; Nakagawa, So; Hashimoto-Gotoh, Akira; Nakaya, Yuki; Shimode, Sayumi; Sakaguchi, Shoichi; Yoshikawa, Rokusuke; Takahashi, Mahoko Ueda; Miyazawa, Takayuki
Retroviral vectors are used for gene transduction into cells and have been applied to gene therapy. Retroviral vectors using envelope protein (Env) of RD-114 virus, a feline endogenous retrovirus, have been used for gene transduction. In this study, we investigated the susceptibility to RD-114 Env-pseudotyped virus in twelve domestic animals including cattle, sheep, horse, pig, dog, cat, ferret, mink, rabbit, rat, mouse, and quail. Comparison of nucleotide sequences of ASCT2 (SLC1A5), a receptor of RD-114 virus, in 10 mammalian and 2 avian species revealed that insertion and deletion events at the region C of ASCT2 where RD-114 viral Env interacts occurred independently in the mouse and rat lineage and in the chicken and quail lineage. By the pseudotype virus infection assay, we found that RD-114 Env-pseudotyped virus could efficiently infect all cell lines except those from mouse and rat. Furthermore, we confirmed that bovine ASCT2 (bASCT2) functions as a receptor for RD-114 virus infection. We also investigated bASCT2 mRNA expression in cattle tissues and found that it is expressed in various tissues including lung, spleen and kidney. These results indicate that retrovirus vectors with RD-114 virus Env can be used for gene therapy in large domestic animals in addition to companion animals such as cat and dog. Copyright © 2015 Elsevier B.V. All rights reserved.
Mascaro Vera Lucia Degaspare Monte
Full Text Available PURPOSE: To report the antifungal susceptibility profile of yeast isolates obtained from cases of keratitis. METHODS: Susceptibility testing of 15 yeast strains isolated from corneal infections to amphotericin B, fluconazole, itraconazole and ketoconazole was performed using the NCCLS broth microdilution assay. RESULTS: Most episodes of eye infections were caused by Candida albicans. The antifungal drugs tested showed the following minimal inhibitory concentration values against yeast isolates: 0.125-0.5 mg/ml for amphotericin B; 0.125->64.0 mg/ml for fluconazole; 0.015-1.0 mg/ml for itraconazole and 0.015-0.125 mg/ml for ketoconazole. Despite the fact that all Candida isolates were judged to be susceptible to azoles, one isolate showed a minimal inhibitory concentration value significantly higher than a 90% minimal inhibitory concentration of all tested isolates. Rhodotorula rubra was resistant to fluconazole and itraconazole. CONCLUSIONS: Despite the fact that most yeast isolates from corneal infections are usually susceptible to amphotericin B and azoles, they exhibit a wide range of minimal inhibitory concentration values for antifungal drugs. The identification of strains at species level and their susceptibility pattern to antifungal drugs should be considered before determining the concentration to be used in topical antifungal formulations in order to optimize therapeutic response in eye infections.
Giardia and Cryptosporidium are frequent parasites of livestock, companion animals, and wildlife, raising questions about the clinical significance of such infections. Infections with both parasites have a wide spectrum of symptoms that can vary between asymptomatic infections to serious infection ...
Picciolo, G. L.; Chappelle, E. W.; Deming, J. W.; Shrock, C. G.; Vellend, H.; Barza, M. J.; Weinstein, L. (Inventor)
A method is described for the quick determination of the susceptibilities of various unidentified bacteria contained in an aqueous physiological fluid sample, particularly urine, to one or more antibiotics. A bacterial adenosine triphosphate (ATP) assay is carried out after the elimination of non-bacterial ATP to determine whether an infection exists. If an infection does exist, a portion of the sample is further processed, including subjecting parts of the portion to one or more antibiotics. Growth of the bacteria in the parts are determined, again by an ATP assay, to determine whether the unidentified bacteria in the sample are susceptible to the antibiotic or antibiotics under test.
Full Text Available Individuals living in sub-Saharan Africa represent 10% of the world's population but almost 2/3 of all HIV-1/AIDS cases. The disproportionate HIV-1 infection rates in this region may be linked to helminthic parasite infections that affect many individuals in the developing world. However, the hypothesis that parasite infection increases an individual's susceptibility to HIV-1 has never been prospectively tested in a relevant in vivo model.We measured whether pre-existing infection of rhesus monkeys with a parasitic worm would facilitate systemic infection after mucosal AIDS virus exposure. Two groups of animals, one consisting of normal monkeys and the other harboring Schistosoma mansoni, were challenged intrarectally with decreasing doses of R5-tropic clade C simian-human immunodeficiency virus (SHIV-C. Systemic infection occurred in parasitized monkeys at viral doses that remained sub-infectious in normal hosts. In fact, the 50% animal infectious (AID(50 SHIV-C dose was 17-fold lower in parasitized animals compared to controls (P<0.001. Coinfected animals also had significantly higher peak viral RNA loads than controls (P<0.001, as well as increased viral replication in CD4(+ central memory cells (P = 0.03.Our data provide the first direct evidence that acute schistosomiasis significantly increases the risk of de novo AIDS virus acquisition, and the magnitude of the effect suggests that control of helminth infections may be a useful public health intervention to help decrease the spread of HIV-1.
Camero, M; Larocca, V; Losurdo, M; Lorusso, E; Patruno, G; Staffa, V N; Martella, V; Buonavoglia, C; Tempesta, M
Herpesvirus infections are generally subjected to strong host species restriction, although virological and serological investigations have revealed the possibility of cross-species infections in closely related animal species. In this study we evaluated susceptibility of goats to infection by Bubaline alphaherpesvirus 1 (BuHV-1). Four goats were inoculated intra-nasally with BuHV-1 and monitored clinically, virologically and serologically for 42days. None of the goats displayed clinical signs although all the animals variably shed the virus by the nasal route during the first 12days after infection. BuHV-1 was also detected in the white blood cells of two animals in the first week post infection. The results suggest that goats are susceptible to BuHV-1 infection and that they could play an epidemiological role in the circulation/transmission of the virus among domestic and wild ruminants and impact to some extent on the control plans for herpesviruses in cattle. Copyright © 2016 Elsevier Ltd. All rights reserved.
Yadav, Bhawna; Malonia, Sunil K; Majumdar, Subeer S; Gupta, Pushpa; Wadhwa, Neerja; Badhwar, Archana; Gupta, Umesh D; Katoch, Vishwa M; Chattopadhyay, Samit
Studies involving animal models of experimental tuberculosis have elucidated the predominant role of cytokines secreted by T cells and macrophages to be an essential component of the immune response against Mycobacterium tuberculosis infection. The immune activities of CD4+ T cells are mediated in part by Th1 cytokine interferon gamma (IFN-γ) which is produced primarily by T cells and natural killer (NK) cells and critical for initiating the immune response against intracellular pathogen such as M. tuberculosis. Nuclear matrix protein SMAR1 plays an important role in V(D)J recombination, T helper cell differentiation and inflammatory diseases. In this study a transgenic mouse model was used to study the role of SMAR1 in M. tuberculosis infection. Wild type BALB/c, C57BL/6, BALB/c-EGFP-SMAR1 and C57BL/6-SMAR1 transgenic mice were infected with M. tuberculosis (H37Rv). A dose of 100 bacilli was used for infection via respiratory route. Bacterial load in lung and spleen of infected mice was determined at 2, 4, 6 and 8 wk post-infection. Gene expression analysis for Th1 cytokines and inducible nitric oxide synthase (iNOS) was performed in infected lung tissues by quantitative reverse transcription (RT)-PCR. SMAR1 transgenic mice from both BALB/c and C57BL/6 genetic background displayed higher bacillary load and susceptibility to M. tuberculosis infection compared to wild type mice. This susceptibility was attributed due to compromised of Th1 response exhibited by transgenic mice. SMAR1 transgenic mice exhibited susceptibility to M. tuberculosis infection in vivo irrespective of genetic background. This susceptibility was attributed to downregulation of Th1 response and its hallmark cytokine IFN-γ. Hence, SMAR1 plays an important role in modulating host immune response after M. tuberculosis infection.
Human respiratory syncytial virus (hRSV) is a major cause of respiratory disease and hospitalisation of infants, worldwide, and is also responsible for significant morbidity in adults and excess deaths in the elderly. There is no licensed hRSV vaccine or effective therapeutic agent. However, there are a growing number of hRSV vaccine candidates that have been developed targeting different populations at risk of hRSV infection. Animal models of hRSV play an important role in the preclinical testing of hRSV vaccine candidates and although many have shown efficacy in preclinical studies, few have progressed to clinical trials or they have had only limited success. This is, at least in part, due to the lack of animal models that fully recapitulate the pathogenesis of hRSV infection in humans. This review summarises the strengths and limitations of animal models of hRSV, which include those in which hRSV is used to infect non-human mammalian hosts, and those in which non-human pneumoviruses, such as bovine (b)RSV and pneumonia virus of mice (PVM) are studied in their natural host. Apart from chimpanzees, other non-human primates (NHP) are only semi-permissive for hRSV replication and experimental infection with large doses of virus result in little or no clinical signs of disease, and generally only mild pulmonary pathology. Other animal models such as cotton rats, mice, ferrets, guinea pigs, hamsters, chinchillas, and neonatal lambs are also only semi-permissive for hRSV. Nevertheless, mice and cotton rats have been of value in the development of monoclonal antibody prophylaxis for infants at high risk of severe hRSV infection and have provided insights into mechanisms of immunity to and pathogenesis of hRSV. However, the extent to which they predict hRSV vaccine efficacy and safety is unclear and several hRSV vaccine candidates that are completely protective in rodent models are poorly effective in chimpanzees and other NHP, such as African Green monkeys. Furthermore
Dias Neto José Anastácio
Full Text Available PURPOSE: Urinary tract infection is the most common nosocomially acquired infection. It is important to know the etiology and antibiotic susceptibility infectious agents to guide the initial empirical treatment. OBJECTIVE: To determine the prevalence of bacterial strains and their antibiotic susceptibility in nosocomially acquired urinary tract infection in a university hospital between January and June 2003. METHODS: We analyzed the data of 188 patients with positive urine culture (= 10(5 colony-forming units/mL following a period of 48 hours after admission. RESULTS: Half of patients were male. Mean age was 50.26 ± 22.7 (SD, range 3 months to 88 years. Gram-negative bacteria were the agent in approximately 80% of cases. The most common pathogens were E. coli (26%, Klebsiella sp. (15%, P. aeruginosa (15% and Enterococcus sp. (11%. The overall bacteria susceptibility showed that the pathogens were more sensible to imipenem (83%, second or third generation cephalosporin and aminoglycosides; and were highly resistant to ampicillin (27% and cefalothin (30%. It is important to note the low susceptibility to ciprofloxacin (42% and norfloxacin (43%. CONCLUSION: This study suggests that if one can not wait the results of urine culture, the best choices to begin empiric treatment are imipenem, second or third generation cephalosporin and aminoglycosides. Cefalothin and ampicillin are quite ineffective to treat these infections.
Full Text Available The development of animal models of dengue virus (DENV infection and disease has been challenging, as epidemic DENV does not naturally infect non-human species. Non-human primates (NHPs can sustain viral replication in relevant cell types and develop a robust immune response, but they do not develop overt disease. In contrast, certain immunodeficient mouse models infected with mouse-adapted DENV strains show signs of severe disease similar to the ‘vascular-leak’ syndrome seen in severe dengue in humans. Humanized mouse models can sustain DENV replication and show some signs of disease, but further development is needed to validate the immune response. Classically, immunocompetent mice infected with DENV do not manifest disease or else develop paralysis when inoculated intracranially; however, a new model using high doses of DENV has recently been shown to develop hemorrhagic signs after infection. Overall, each model has its advantages and disadvantages and is differentially suited for studies of dengue pathogenesis and immunopathogenesis and/or pre-clinical testing of antiviral drugs and vaccines.
Zompi, Simona; Harris, Eva
The development of animal models of dengue virus (DENV) infection and disease has been challenging, as epidemic DENV does not naturally infect non-human species. Non-human primates (NHPs) can sustain viral replication in relevant cell types and develop a robust immune response, but they do not develop overt disease. In contrast, certain immunodeficient mouse models infected with mouse-adapted DENV strains show signs of severe disease similar to the 'vascular-leak' syndrome seen in severe dengue in humans. Humanized mouse models can sustain DENV replication and show some signs of disease, but further development is needed to validate the immune response. Classically, immunocompetent mice infected with DENV do not manifest disease or else develop paralysis when inoculated intracranially; however, a new model using high doses of DENV has recently been shown to develop hemorrhagic signs after infection. Overall, each model has its advantages and disadvantages and is differentially suited for studies of dengue pathogenesis and immunopathogenesis and/or pre-clinical testing of antiviral drugs and vaccines.
Carvalho Leonardo JM
Full Text Available Aotus is one of the WHO-recommended primate models for studies in malaria, and several species can be infected with Plasmodium falciparum or P. vivax. Here we describe the successful infection of the species A. infulatus from eastern Amazon with blood stages of P. falciparum. Both intact and splenectomized animals were susceptible to infection; the intact ones were able to keep parasitemias at lower levels for several days, but developed complications such as severe anemia; splenectomized monkeys developed higher parasitemias but no major complications. We conclude that A. infulatus is susceptible to P. falciparum infection and may represent an alternative model for studies in malaria.
Cai, Chao-Ran; Chen, Michael Z Q; Holme, Petter; Guan, Jian-Yue
The Susceptible-Infected-Susceptible model is a canonical model for emerging disease outbreaks. Such outbreaks are naturally modeled as taking place on networks. A theoretical challenge in network epidemiology is the dynamic correlations coming from that if one node is occupied, or infected (for disease spreading models), then its neighbors are likely to be occupied. By combining two theoretical approaches---the heterogeneous mean-field theory and the effective degree method---we are able to include these correlations in an analytical solution of the SIS model. We derive accurate expressions for the average prevalence (fraction of infected) and epidemic threshold. We also discuss how to generalize the approach to a larger class of stochastic population models.
Mata, Angélica S
We show that the susceptible-infected-susceptible (SIS) epidemic dynamics running on the top of networks with a power law degree distribution can exhibit multiple phase transitions. Three main transitions involving different mechanisms responsible by sustaining the epidemics are identified: A short-term epidemics concentrated around the most connected vertex; a long-term (asymptotically stable) localized epidemics with a vanishing threshold; and an endemic phase occurring at a finite threshold. The different transitions are suited through different mean-field approaches. We finally show that the multiple transitions are due to the activations of different domains of the network that are observed in rapid (singular) variations of both stationary density of infected vertices and the participation ratio against the infection rate.
Ismail, Siti Suhaila; Akil, Ku Azlina Ku; Chulan, Majdah; Sharif, Noorzila
Viral marketing is a marketing strategy utilizes social media to spread information about a product or services provided. It is the most powerful way to share information in a short amount of time. The objective of this study is to investigate the dynamic of viral marketing within a time duration in the point of view of mathematics. This study used the epidemiological model known as Susceptible-Infected-Recovered (SIR). The model consists of a system of three differential equations with three state variables namely susceptible (S), infected (I) and recovered (R). It considers a case of SIR model with demography. Numerical experiments have been performed. The results show that viral marketing reaches its peak within two days. The online messages shared will become higher if the initial number of the infected individual has been increased.
Hagstrand Aldman, Malin; Skovby, Annette; I Påhlman, Lisa
Staphylococcus aureus (SA) is an important human pathogen that causes both superficial and invasive infections. Penicillin is now rarely used in the treatment of SA infections due to widespread resistance and a concern about the accuracy of existing methods for penicillin susceptibility testing. The aims of the present study were to determine the frequency of penicillin-susceptible SA isolates from blood and wound cultures in Lund, Sweden, and to evaluate methods for penicillin testing in SA. We also wanted to investigate if penicillin-susceptible isolates are associated with higher mortality. Hundred blood culture isolates collected 2008/2009, 140 blood culture isolates from 2014/2015, and 141 superficial wound culture strains from 2015 were examined. Penicillin susceptibility was tested with disk diffusion according to EUCAST guidelines, and results were confirmed with a cloverleaf assay and PCR amplification of the BlaZ gene. Patient data for all bacteraemia cases were extracted from medical records. The disk diffusion method with assessment of both zone size and zone edge appearance had high accuracy in our study. About 57% of bacteraemia isolates from 2008/2009 were sensitive to penicillin compared to 29% in 2014/2015 (p penicillin susceptible. There was no difference in co-morbidity or mortality rates between patients with penicillin resistant and penicillin sensitive SA bacteraemia. Disk-diffusion is a simple and reliable method to detect penicillin resistance in SA, and susceptibility rates are significant. Penicillin has many theoretical advantages and should be considered in the treatment of SA bacteraemia when susceptible.
Kévin P. Dhondt
Full Text Available The Henipavirus genus contains two highly lethal viruses, the Hendra and Nipah viruses and one, recently discovered, apparently nonpathogenic member; Cedar virus. These three, negative-sense single-stranded RNA viruses, are hosted by fruit bats and use EphrinB2 receptors for entry into cells. The Hendra and Nipah viruses are zoonotic pathogens that emerged in the middle of 90s and have caused severe, and often fatal, neurologic and/or respiratory diseases in both humans and different animals; including spillover into equine and porcine species. Development of relevant models is critical for a better understanding of viral pathogenesis, generating new diagnostic tools, and assessing anti-viral therapeutics and vaccines. This review summarizes available data on several animal models where natural and/or experimental infection has been demonstrated; including pteroid bats, horses, pigs, cats, hamsters, guinea pigs, ferrets, and nonhuman primates. It recapitulates the principal features of viral pathogenesis in these animals and current knowledge on anti-viral immune responses. Lastly it describes the recently characterized murine animal model, which provides the possibility to use numerous and powerful tools available for mice to further decipher henipaviruses immunopathogenesis, prophylaxis, and treatment. The utility of different models to analyze important aspects of henipaviruses-induced disease in humans, potential routes of transmission, and therapeutic approaches are equally discussed.
Full Text Available Abstract Background Mycoplasma fermentans has been associated with respiratory, genitourinary tract infections and rheumatoid diseases but its role as pathogen is controversial. The purpose of this study was to probe that Mycoplasma fermentans is able to produce respiratory tract infection and migrate to several organs on an experimental infection model in hamsters. One hundred and twenty six hamsters were divided in six groups (A-F of 21 hamsters each. Animals of groups A, B, C were intratracheally injected with one of the mycoplasma strains: Mycoplasma fermentans P 140 (wild strain, Mycoplasma fermentans PG 18 (type strain or Mycoplasma pneumoniae Eaton strain. Groups D, E, F were the negative, media, and sham controls. Fragments of trachea, lungs, kidney, heart, brain and spleen were cultured and used for the histopathological study. U frequency test was used to compare recovery of mycoplasmas from organs. Results Mycoplasmas were detected by culture and PCR. The three mycoplasma strains induced an interstitial pneumonia; they also migrated to several organs and persisted there for at least 50 days. Mycoplasma fermentans P 140 induced a more severe damage in lungs than Mycoplasma fermentans PG 18. Mycoplasma pneumoniae produced severe damage in lungs and renal damage. Conclusions Mycoplasma fermentans induced a respiratory tract infection and persisted in different organs for several weeks in hamsters. This finding may help to explain the ability of Mycoplasma fermentans to induce pneumonia and chronic infectious diseases in humans.
Yáñez, Antonio; Martínez-Ramos, Azucena; Calixto, Teresa; González-Matus, Francisco Javier; Rivera-Tapia, José Antonio; Giono, Silvia; Gil, Constantino; Cedillo, Lilia
Mycoplasma fermentans has been associated with respiratory, genitourinary tract infections and rheumatoid diseases but its role as pathogen is controversial. The purpose of this study was to probe that Mycoplasma fermentans is able to produce respiratory tract infection and migrate to several organs on an experimental infection model in hamsters. One hundred and twenty six hamsters were divided in six groups (A-F) of 21 hamsters each. Animals of groups A, B, C were intratracheally injected with one of the mycoplasma strains: Mycoplasma fermentans P 140 (wild strain), Mycoplasma fermentans PG 18 (type strain) or Mycoplasma pneumoniae Eaton strain. Groups D, E, F were the negative, media, and sham controls. Fragments of trachea, lungs, kidney, heart, brain and spleen were cultured and used for the histopathological study. U frequency test was used to compare recovery of mycoplasmas from organs. Mycoplasmas were detected by culture and PCR. The three mycoplasma strains induced an interstitial pneumonia; they also migrated to several organs and persisted there for at least 50 days. Mycoplasma fermentans P 140 induced a more severe damage in lungs than Mycoplasma fermentans PG 18. Mycoplasma pneumoniae produced severe damage in lungs and renal damage. Mycoplasma fermentans induced a respiratory tract infection and persisted in different organs for several weeks in hamsters. This finding may help to explain the ability of Mycoplasma fermentans to induce pneumonia and chronic infectious diseases in humans.
Ettie M Lipner
Full Text Available Tuberculosis and nontuberculous mycobacterial infections constitute a high burden of pulmonary disease in humans, resulting in over 1.5 million deaths per year. Building on the premise that genetic factors influence the instance, progression, and defense of infectious disease, we undertook a systems biology approach to investigate relationships among genetic factors that may play a role in increased susceptibility or control of mycobacterial infections. We combined literature and database mining with network analysis and pathway enrichment analysis to examine genes, pathways, and networks, involved in the human response to Mycobacterium tuberculosis and nontuberculous mycobacterial infections. This approach allowed us to examine functional relationships among reported genes, and to identify novel genes and enriched pathways that may play a role in mycobacterial susceptibility or control. Our findings suggest that the primary pathways and genes influencing mycobacterial infection control involve an interplay between innate and adaptive immune proteins and pathways. Signaling pathways involved in autoimmune disease were significantly enriched as revealed in our networks. Mycobacterial disease susceptibility networks were also examined within the context of gene-chemical relationships, in order to identify putative drugs and nutrients with potential beneficial immunomodulatory or anti-mycobacterial effects.
Cui, Ai-Xiang; Zhou, Tao
Understanding spreading dynamics will benefit society as a whole in better preventing and controlling diseases, as well as facilitating the socially responsible information while depressing destructive rumors. In network-based spreading dynamics, edges with different weights may play far different roles: a friend from afar usually brings novel stories, and an intimate relationship is highly risky for a flu epidemic. In this article, we propose a weighted susceptible-infected-susceptible model on complex networks, where the weight of an edge is defined by the topological proximity of the two associated nodes. Each infected individual is allowed to select limited number of neighbors to contact, and a tunable parameter is introduced to control the preference to contact through high-weight or low-weight edges. Experimental results on six real networks show that the epidemic prevalence can be largely promoted when strong ties are favored in the spreading process. By comparing with two statistical null models respe...
Bastos, Reginaldo G; Howard, Zachary P; Hiroyasu, Aoi; Goodman, Alan G
Coxiella burnetii is the causative agent of Q fever, a zoonotic disease that threatens both human and animal health. Due to the paucity of experimental animal models, little is known about how host factors interface with bacterial components and affect pathogenesis. Here, we used Drosophila melanogaster, in conjunction with the biosafety level 2 (BSL2) Nine Mile phase II (NMII) clone 4 strain of C. burnetii, as a model to investigate host and bacterial components implicated in infection. We demonstrate that adult Drosophila flies are susceptible to C. burnetii NMII infection and that this bacterial strain, which activates the immune deficiency (IMD) pathway, is able to replicate and cause mortality in the animals. We show that in the absence of Eiger, the only known tumor necrosis factor (TNF) superfamily homolog in Drosophila, Coxiella-infected flies exhibit reduced mortality from infection. We also demonstrate that the Coxiella type 4 secretion system (T4SS) is critical for the formation of the Coxiella-containing vacuole and establishment of infection in Drosophila Altogether, our data reveal that the Drosophila TNF homolog Eiger and the Coxiella T4SS are implicated in the pathogenesis of C. burnetii in flies. The Drosophila/NMII model mimics relevant aspects of the infection in mammals, such as a critical role of host TNF and the bacterial T4SS in pathogenesis. Our work also demonstrates the usefulness of this BSL2 model to investigate both host and Coxiella components implicated in infection. Copyright © 2017 American Society for Microbiology.
Shaw, M.A.; Davis, C.R.; Collins, A. [and others
Racial differences, familial clustering, and murine studies are suggestive of host genetic control of Leishmania infections. Complex segregation analysis has been carried out by use of the programs POINTER and COMDS and data from a total population survey, comprising 636 nuclear families, from an L. perurviana endemic area. The data support genetic components controlling susceptibility to clinical leishmaniasis, influencing severity of disease and resistance to disease among healthy individuals. A multifactorial model is favored over a sporadic model. Two-locus models provided the best fit to the data, the optimal model being a recessive gene (frequency .57) plus a modifier locus. Individuals infected at an early age and with recurrent lesions are genetically more susceptible than those infected with a single episode of disease at a later age. Among people with no lesions, those with a positive skin-test response are genetically less susceptible than those with a negative response. The possibility of the involvement of more than one gene together with environmental effects has implications for the design of future linkage studies. 31 refs., 7 tabs.
Kroemer, Stéphane; El Garch, Farid; Galland, Delphine; Petit, Jean-Luc; Woehrle, Frédérique; Boulouis, Henri-Jean
A monitoring program of the pre-treatment susceptibility of clinical isolates of bacteria from diseased dogs and cats was active between the years 2002 and 2009. Susceptibility of each isolated strain to a panel of nine antibiotics (amoxicillin/clavulanic acid, ampicillin, penicillin, clindamycin, doxycycline, enrofloxacin, marbofloxacin, trimethoprim and trimethoprim/sulfamethoxazole) was assessed. The Minimum Inhibitory Concentration (MIC) of marbofloxacin was also determined by a standardized microdilution technique following CLSI recommendations. In total, 1857 bacterial strains were collected throughout Europe from cases of otitis, respiratory, urinary and dermatological infections. Although bacterial susceptibility varied for each of the antibiotics within the panel, patterns of susceptibility were similar to those described in the literature for comparable time periods and geographical areas. With a clinical resistance varying from 0 to 14.48% against the isolated strains, marbofloxacin susceptibility was very high and remains an effective antibiotic for the treatment of otitis, urinary, respiratory and dermatological infections in companion animals. Copyright © 2014. Published by Elsevier Ltd.
Full Text Available Squamous cell carcinoma of the cervix (SCCC is one of the leading causes of death in developing countries. Infection with high-risk human papillomavirus (HPV is the major risk factor to develop malignant lesions in the cervix. Polymorphisms of the MHC and p53 genes seem to influence the outcome of HPV infection and progression to SCCC, although controversial data have been reported. MHC are highly polymorphic genes that encode molecules involved in antigen presentation, playing a key role in immune regulation, while p53 is a tumor suppressor gene that regulates cell proliferation. The HPV E6 protein from high-risk types binds p53 and mediates its degradation by the ubiquitin pathway. The role of these polymorphisms in genetic susceptibility to HPV infection and to SCCC remains under investigation.
Full Text Available Background: Urinary tract infections are a serious health problem affecting millions of people each year.They are the second most common type of infection in the body.The objective of study was to determine the etiology and antimicrobial susceptibility patterns of urinary tract infections pathogens isolated in our Patology Clinic laboratory. Materials and Methods: During the period July 2007- July 2008,were analysed 1422 urine samples.The determination of the total microbe load were acquire with an kit of the BIO-DETECTOR while the identification of germs with Apy sistem. Antibiotic susceptibility tests were assaied with the ATB UR strip. Results: About the total of samples analysed, 320 (22% had significant bacteriuria. Escherichia coli was the most common etiologic agent isolated (62%, followed by Klebsiella ssp. (10%, Pseudomonas aeruginosa (5,95% and Proteus mirabilis (5%. Gram-positive bacteria accounted for only 7.32% , with prevalence of Staphylococcus ssp (5,32 and Enterococcus spp (2%. The most effective antibiotics for Gram- were: Imipenem, Amikacin, Ceftazidime and Cefotaxim, while for Gram+ were: Minocyclin,Vancomycin and Oxacillin. Conclusion: Escherichia coli was the microrganism more frequently isolated between Gram negative bacteria with very susceptible to Amoxicillin. Currently, the empirical use of Cotrimoxazole and Amoxicillin is not recommended for Enterobacteriaceae. Urinary tract infections are more common in women than in men. Men are more likely to get a UTI once past the age of 65. Current data on the prevalence of multidrug resistance among urinary tract isolates should be a consideration to change the current empiric treatment of IVU.
Zélé, F.; Nicot, A.; Berthomieu, A.; Weill, M.; Duron, O.; Rivero, A.
Current views about the impact of Wolbachia on Plasmodium infections are almost entirely based on data regarding artificially transfected mosquitoes. This work has shown that Wolbachia reduces the intensity of Plasmodium infections in mosquitoes, raising the exciting possibility of using Wolbachia to control or limit the spread of malaria. Whether natural Wolbachia infections have the same parasite-inhibiting properties is not yet clear. Wolbachia–mosquito combinations with a long evolutionary history are, however, key for understanding what may happen with Wolbachia-transfected mosquitoes after several generations of coevolution. We investigate this issue using an entirely natural mosquito–Wolbachia–Plasmodium combination. In contrast to most previous studies, which have been centred on the quantification of the midgut stages of Plasmodium, we obtain a measurement of parasitaemia that relates directly to transmission by following infections to the salivary gland stages. We show that Wolbachia increases the susceptibility of Culex pipiens mosquitoes to Plasmodium relictum, significantly increasing the prevalence of salivary gland stage infections. This effect is independent of the density of Wolbachia in the mosquito. These results suggest that naturally Wolbachia-infected mosquitoes may, in fact, be better vectors of malaria than Wolbachia-free ones. PMID:24500167
Schikora, Adam; Virlogeux-Payant, Isabelle; Bueso, Eduardo; Garcia, Ana V; Nilau, Theodora; Charrier, Amélie; Pelletier, Sandra; Menanteau, Pierrette; Baccarini, Manuela; Velge, Philippe; Hirt, Heribert
Salmonella virulence in animals depends on effectors injected by Type III Secretion Systems (T3SSs). In this report we demonstrate that Salmonella mutants that are unable to deliver effectors are also compromised in infection of Arabidopsis thaliana plants. Transcriptome analysis revealed that in contrast to wild type bacteria, T3SS mutants of Salmonella are compromised in suppressing highly conserved Arabidopsis genes that play a prominent role during Salmonella infection of animals. We also found that Salmonella originating from infected plants are equally virulent for human cells and mice. These results indicate a high degree of conservation in the defense and infection mechanism of animal and plant hosts during Salmonella infection.
Woo, P T; Wehnert, S D
Using the sealed jar technique (also called residual oxygen bioassay), rainbow trout fry infected with Cryptobia salmositica were more susceptible than non-infected fish to environmental hypoxia. The Winkler technique (azide modification) was used to determine the residual dissolved oxygen in the water. Susceptibility of infected fish increased with 1) time after infection and was most evident in 3-7 wk infections, 2) the severity of anemia, and 3) increasing parasitemia. In prolonged infections, susceptibility was reduced when there were decreases in anemia and parasitemia; however, these infected fish were still more susceptible than non-infected fish. The increase in susceptibility of infected fish to hypoxia may be an important contributing factor to mortality of fish in hatcheries where there is inadequate water flow and overcrowding. The sealed jar technique is recommended in future studies on the pathogenesis of parasitic fish diseases, especially if the metabolic and/or respiratory systems are affected by the infection.
Mortensen, Laust Hvas; Maier, A B; Slagbom, P E
genetically informative cohorts. From the Leiden Longevity Study (LLS) we selected long-lived sib-pairs (n=844) and their middle-aged offspring and the offspring's partners (n=1452). From the Longitudinal Study of Aging Danish Twins (LSADT) 604 (302 pairs) same-sex monozygotic (MZ) and dizygotic (DZ) twins...... number for partners was 71% (Penvironment accounts for the similarity within twin pairs. Our findings suggest that susceptibility to CMV infection......--even under continuous within-partnership exposure--appears to be more strongly influenced by early-life environment than by genetic factors and adult environment....
Aviles, Hernan; Belay, Tesfaye; Fountain, Kimberly; Vance, Monique; Sonnenfeld, Gerald
It has been reported that spaceflight conditions alter the immune system and resistance to infection [Belay T, Aviles H, Vance M, Fountain K, and Sonnenfeld G. J Allergy Clin Immunol 170: 262-268, 2002; Hankins WR and Ziegelschmid JF. In: Biomedical Results of Apollo. Washington, DC: NASA, 1975, p. 43-81. (NASA Spec. Rep. SP-368)]. Ground-based models, including the hindlimb-unloading model, have become important tools for increasing understanding of how spaceflight conditions can influence physiology. The objective of the present study was to determine the effect of hindlimb unloading on the susceptibility of mice to Pseudomonas aeruginosa infection. Hindlimb-unloaded and control mice were subcutaneously infected with 1 LD50 of P. aeruginosa. Survival, bacterial organ load, and antibody and corticosterone levels were compared among the groups. Hindlimb unloading had detrimental effects for infected mice. Animals in the hindlimb-unloaded group, compared with controls, 1). showed significantly increased mortality and reduced time to death, 2). had increased levels of corticosterone, and 3). were much less able to clear bacteria from the organs. These results suggest that hindlimb unloading may induce the production of corticosterone, which may play a critical role in the modulation of the immune system leading to increased susceptibility to P. aeruginosa infection.
Reddy, A K; Garg, P; Kaur, I
Twenty Nocardia spp. isolated from ocular infections were identified by 16S rRNA gene sequencing and susceptibility was determined using the E-test (AB Biodisk, Sweden). Species distribution among the 20 isolates was as follows: Nocardia levis (n = 7), Nocardia farcinica (n = 3), Nocardia abscessus (n = 2), Nocardia brasiliensis (n = 2), Nocardia amamiensis (n = 2), Nocardia puris (n = 1), Nocardia beijingensis (n = 1), Nocardia otitidiscaviarum (n = 1) and Nocardia thailandica (n = 1). All isolates were sensitive to amikacin. Eighteen (90%) isolates were sensitive to tobramycin, 11 (55%) to ciprofloxacin and gatifloxacin, and seven (35%) to azithromycin and clarithromycin. Molecular methods are useful for the identification and for the detection of Nocardia species that have not so far been reported in human infections.
Dias Neto José Anastácio
Full Text Available PURPOSE: Urinary tract infections (UTI are one of the most common infectious diseases diagnosed. UTI account for a large proportion of antibacterial drug consumption and have large socio-economic impacts. Since the majority of the treatments begins or is done completely empirically, the knowledge of the organisms, their epidemiological characteristics and their antibacterial susceptibility that may vary with time is mandatory. OBJECTIVE: The aim of this study was to report the prevalence of uropathogens and their antibiotic susceptibility of the community acquired UTI diagnosed in our institution and to provide a national data. METHODS: We analyzed retrospectively the results of urine cultures of 402 patients that had community acquired urinary tract infection in the year of 2003. RESULTS: The mean age of the patients in this study was 45.34 ± 23.56 (SD years. There were 242 (60.2% females and 160 (39.8% males. The most commonly isolated organism was Escherichia coli (58%. Klebsiella sp. (8.4% and Enterococcus sp.(7.9% were reported as the next most common organisms. Of all bacteria isolated from community acquired UTI, only 37% were sensitive to ampicillin, 51% to cefalothin and 52% to trimethoprim/sulfamethoxazole. The highest levels of susceptibility were to imipenem (96%, ceftriaxone (90%, amikacin (90%, gentamicin (88%, levofloxacin (86%, ciprofloxacin (73%, nitrofurantoin (77% and norfloxacin (75%. CONCLUSION: Gram-negative agents are the most common cause of UTI. Fluoroquinolones remains the choice among the orally administered antibiotics, followed by nitrofurantoin, second and third generation cephalosporins. For severe disease that require parenteral antibiotics the choice should be aminoglycosides, third generation cephalosporins, fluoroquinolones or imipenem, which were the most effective.
Skovgaard, Kerstin; Brogaard, Louise; Larsen, Lars Erik
infiltration of the respiratory system. This study aimed at providing a better understanding of the involvement of innate immune factors and non-coding RNA in blood leukocytes during influenza A virus infection. By using the pig as a model we were able to perform highly controlled experimental infections...... consolidate the pig as a valuable model for influenza A virus infection.......It is increasingly realized that large animal models like the pig are exceptionally human like and serve as an excellent model for disease and inflammation. Pigs are fully susceptible to human influenza, share many similarities with humans regarding lung physiology and innate immune cell...
Jocelyn A. Claude
Full Text Available Studies suggest childhood exposure to environmental tobacco smoke (ETS leads to increased incidence of infections of the lower respiratory tract. The objective of this study was to determine whether perinatal exposure to ETS increases the incidence, morbidity and severity of respiratory influenza infection and whether a secondary bacterial challenge at the peak of a pre-existing viral infection creates an enhanced host-pathogen susceptibility to an opportunistic infection. Timed-pregnant female Balb/c mice were exposed to either ETS for 6 h/day, 7 d/week beginning on gestation day 14 and continuing with the neonates to 6 weeks of age. Control animals were exposed to filtered air (FA. At the end of exposure, mice were intranasally inoculated with a murine-adapted influenza A. One week later, an intranasal inoculation of S. aureus bacteria was administered. The respective treatment groups were: bacteria only, virus only or virus+bacteria for both FA and ETS-exposed animals for a total of six treatment groups. Animal behavior and body weights were documented daily following infection. Mice were necropsied 1-day post-bacterial infection. Bronchoalveolar lavage fluid (BALF cell analysis demonstrated perinatal exposure to ETS, compared to FA, leads to delayed but enhanced clinical symptoms and enhanced total cell influx into the lungs associated with viral infection followed by bacterial challenge. Viral infection significantly increases the number of neutrophils entering the lungs following bacterial challenge with either FA or ETS exposure, while the influx of lymphocytes and monocytes is significantly enhanced only by perinatal ETS exposure. There is a significant increase in peribronchiolar inflammation following viral infection in pups exposed to ETS compared with pups exposed to FA, but no change is noted in the degree of lung injury between FA and ETS-exposed animals following bacterial challenge. The data suggests perinatal exposure to ETS
Hartshorn Kevan L
Full Text Available Abstract Background Mannose-binding lectin (MBL, a pattern recognition innate immune molecule, inhibits influenza A virus infection in vitro. MBL deficiency due to gene polymorphism in humans has been associated with infection susceptibility. These clinical observations were confirmed by animal model studies, in which mice genetically lacking MBL were susceptible to certain pathogens, including herpes simplex virus 2. Results We demonstrate that MBL is present in the lung of naïve healthy wild type (WT mice and that MBL null mice are more susceptible to IAV infection. Administration of recombinant human MBL (rhMBL reverses the infection phenotype, confirming that the infection susceptibility is MBL-mediated. The anti-viral mechanisms of MBL include activation of the lectin complement pathway and coagulation, requiring serum factors. White blood cells (WBCs in the lung increase in WT mice compared with MBL null mice on day 1 post-infection. In contrast, apoptotic macrophages (MΦs are two-fold higher in the lung of MBL null mice compared with WT mice. Furthermore, MBL deficient macrophages appear to be susceptible to apoptosis in vitro. Lastly, soluble factors, which are associated with lung injury, are increased in the lungs of MBL null mice during IAV infection. These results suggest that MBL plays a key role against IAV infection. Conclusion MBL plays a key role in clearing IAV and maintaining lung homeostasis. In addition, our findings also suggest that MBL deficiency maybe a risk factor in IAV infection and MBL may be a useful adjunctive therapy for IAV infection.
Elias, D; Akuffo, H; Thors, C
The incidence of mycobacterial diseases is high and the efficacy of Bacillus Calmette Guerin (BCG) is low in most areas of the world where chronic worm infections are common. However, if and how concurrent worm infections could affect immunity to mycobacterial infections has not been elucidated....... In this study we investigated whether infection of mice with Schistosoma mansoni could affect the ability of the animals to control Mycobacterium bovis BCG infection and the immune response to mycobacterial antigens. BALB/c mice subclinically infected with S. mansoni were challenged with M. bovis BCG via...... the intravenous route. The ability of the animals to contain the replication of M. bovis BCG in their organs, lung pathology as well as the in vitro mycobacterial and worm antigen induced immune responses were evaluated. The results showed that S. mansoni coinfected mice had significantly higher levels of BCG...
Baron, Miriam J; Wong, Sandra L; Nybakken, Kent; Carey, Vincent J; Madoff, Lawrence C
Many pathogens engage host cell surface glycosaminoglycans, but redundancy in pathogen adhesins and host glycosaminoglycan-anchoring proteins (heparan sulfate proteoglycans) has limited the understanding of the importance of glycosaminoglycan binding during infection. The alpha C protein of group B streptococcus, a virulence determinant for this neonatal human pathogen, binds to host glycosaminoglycan and mediates the entry of bacteria into human cells. We studied alpha C protein-glycosaminoglycan binding in Drosophila melanogaster, whose glycosaminoglycan repertoire resembles that of humans but whose genome includes only three characterized membrane heparan sulfate proteoglycan genes. The knockdown of glycosaminoglycan polymerases or of heparan sulfate proteoglycans reduced the cellular binding of alpha C protein. The interruption of alpha C protein-glycosaminoglycan binding was associated with longer host survival and a lower bacterial burden. These data indicate that the glycosaminoglycan-alpha C protein interaction involves multiple heparan sulfate proteoglycans and impairs bacterial killing. Host glycosaminoglycans, anchored by multiple proteoglycans, thereby determine susceptibility to infection. Because there is homology between Drosophila and human glycosaminoglycan/proteoglycan structures and many pathogens express glycosaminoglycan-binding structures, our data suggest that interfering with glycosaminoglycan binding may protect against infections in humans.
Moreno, Luisa Z; Matajira, Carlos E C; Gomes, Vasco T M; Silva, Ana Paula S; Mesquita, Renan E; Christ, Ana Paula G; Sato, Maria Inês Z; Moreno, Andrea M
Aerococcus viridans has been reported as a human and animal pathogen causing urinary tract infection, arthritis, pneumonia, meningitis and endocarditis. Routinely, A. viridans is not surveyed in clinical diagnosis laboratories and commonly is misidentified as other bacteria. There is no concrete data on the prevalence and impact of the pathogen to both human and animal health. In the present study, we report the isolation and molecular and antibiotic susceptibility characterization of A. viridans strains from porcine urinary infections. A total of 22 isolates were identified as A. viridans by MALDI-TOF MS and confirmed by 16S rRNA gene sequencing. Isolates were genotyped by single enzyme amplified fragments length polymorphism (SE-AFLP) that resulted in 19 clusters of which 81.2% were composed by single isolates. The high genetic heterogeneity corroborates previous studies and appears to be a particularity of A. viridans. The minimal inhibitory concentration (MIC) values also presented variability especially for ceftiofur, fluoroquinolones and aminoglycosides. The high MICs of aminoglycosides, tetracyclines and macrolides seen among the A. viridans corroborate previous reports and the widespread veterinary usage of these antibiotics demand attention for the implication of A. viridans infection to both human and animal health. Copyright © 2016 Elsevier B.V. All rights reserved.
Full Text Available Aim: Increased sodium/calcium exchanger activity (NCX1, an important regulator of cardiomyocyte cystolic calcium may provoke arrhythmias. Exercise training can decrease NCX1 expression in animals with heart failure improving cytosolic calcium regulation, and could thereby reduce the risk for ventricular fibrillation (VF. Methods: To test this hypothesis, a 2-min coronary occlusion was made during the last min. of exercise in dogs with healed myocardial infarctions; 23 had VF (S, susceptible and 13 did not (R, resistant. The animals were randomly assigned to either 10-wk exercise training (progressively increasing treadmill running (S n = 9; R n = 8 or 10-wk sedentary (S n = 14; R n = 5 groups. At the end of the 10-wk period, the exercise + ischemia test provoked VF in sedentary but not trained susceptible dogs. On a subsequent day, cardiac tissue was harvested and NCX1 protein expression was determined by Western blot. Results: In the sedentary group, NCX1 expression was significantly (ANOVA, P<0.05 higher in susceptible compared to resistant dogs. In contrast, NCX1 levels were similar in the exercise trained resistant and susceptible animals. Conclusion: These data suggest that exercise training can restore a more normal NCX1 level in dogs susceptible to ventricular fibrillation, improving cystolic calcium regulation and could thereby reduce the risk for sudden death following myocardial infarction.
Bessa, Lucinda J; Fazii, Paolo; Di Giulio, Mara; Cellini, Luigina
Wound infection plays an important role in the development of chronicity, delaying wound healing. This study aimed to identify the bacterial pathogens present in infected wounds and characterise their resistance profile to the most common antibiotics used in therapy. Three hundred and twelve wound swab samples were collected from 213 patients and analysed for the identification of microorganisms and for the determination of their antibiotic susceptibility. Patients with diverse type of wounds were included in this retrospective study, carried out from March to September 2012. A total of 28 species were isolated from 217 infected wounds. The most common bacterial species detected was Staphylococcus aureus (37%), followed by Pseudomonas aeruginosa (17%), Proteus mirabilis (10%), Escherichia coli (6%) and Corynebacterium spp. (5%). Polymicrobial infection was found in 59 (27·1%) of the samples and was mainly constituted with two species. The most common association was S. aureus/P. aeruginosa. All Gram-positives were susceptible to vancomycin and linezolid. Gram-negatives showed quite high resistance to the majority of antibiotics, being amikacin the most active against these bacteria. This study is mostly oriented to health care practitioners who deal with wound management, making them aware about the importance of wound infection and helping them to choose the adequate treatment options to control microbial infection in wounds. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.
Full Text Available Salmonella virulence in animals depends on effectors injected by Type III Secretion Systems (T3SSs. In this report we demonstrate that Salmonella mutants that are unable to deliver effectors are also compromised in infection of Arabidopsis thaliana plants. Transcriptome analysis revealed that in contrast to wild type bacteria, T3SS mutants of Salmonella are compromised in suppressing highly conserved Arabidopsis genes that play a prominent role during Salmonella infection of animals. We also found that Salmonella originating from infected plants are equally virulent for human cells and mice. These results indicate a high degree of conservation in the defense and infection mechanism of animal and plant hosts during Salmonella infection.
Full Text Available The two classical forms of human trypanosomoses are sleeping sickness due to Trypanosoma brucei gambiense or T. brucei rhodesiense, and Chagas disease due to T. cruzi. However, a number of atypical human infections caused by other T. species (or sub-species have been reported, namely due to T. brucei brucei, T. vivax, T. congolense, T. evansi, T. lewisi, and T. lewisi-like. These cases are reviewed here. Some infections were transient in nature, while others required treatments that were successful in most cases, although two cases were fatal. A recent case of infection due to T. evansi was related to a lack of apolipoprotein L-I, but T. lewisi infections were not related to immunosuppression or specific human genetic profiles. Out of 19 patients, eight were confirmed between 1974 and 2010, thanks to improved molecular techniques. However, the number of cases of atypical human trypanosomoses might be underestimated. Thus, improvement, evaluation of new diagnostic tests, and field investigations are required for detection and confirmation of these atypical cases.
Verwilghen, Denis; Singh, Ameet
A diverse array of pathogen-related, patient-related, and caretaker-related issues influence risk and prevention of surgical site infections (SSIs). The entire surgical team involved in health care settings in which surgical procedures are performed play a pivotal role in the prevention of SSIs. ...
Gessner, Melissa A; Doran, Stephen F; Yu, Zhihong; Dunaway, Chad W; Matalon, Sadis; Steele, Chad
Chlorine (Cl₂) is a highly irritating and reactive gas with potential occupational and environmental hazards. Acute exposure to Cl₂ induces severe epithelial damage, airway hyperreactivity, impaired alveolar fluid clearance, and pulmonary edema in the presence of heightened inflammation and significant neutrophil accumulation in the lungs. Herein, we investigated whether Cl₂ exposure affected the lung antimicrobial immune response leading to increased susceptibility to opportunistic infections. Mice exposed to Cl₂ and challenged intratracheally 24 h thereafter with the opportunistic mold Aspergillus fumigatus demonstrated an >500-fold increase in A. fumigatus lung burden 72 h postchallenge compared with A. fumigatus mice exposed to room air. Cl₂-exposed A. fumigatus challenged mice also demonstrated significantly higher lung resistance following methacholine challenge and increased levels of plasma proteins (albumin and IgG) in the bronchoalveolar lavage fluid. Despite enhanced recruitment of inflammatory cells to the lungs of Cl₂-exposed A. fumigatus challenged mice, these cells (>60% of which were neutrophils) demonstrated a profound impairment in generating superoxide. Significantly higher A. fumigatus burden in the lungs of Cl₂ exposed mice correlated with enhanced production of IL-6, TNF-α, CXCL1, CCL2, and CCL3. Surprisingly, however, Cl₂-exposed A. fumigatus challenged mice had a specific impairment in the production of IL-17A and IL-22 in the lungs compared with mice exposed to room air and challenged with A. fumigatus. In summary, our results indicate that Cl₂ exposure markedly impairs the antimicrobial activity and inflammatory reactivity of myeloid cells in the lung leading to increased susceptibility to opportunistic pathogens.
Garred, P; Madsen, H O; Halberg, P
To determine whether variant alleles in the coding portion of the mannose-binding lectin (MBL) gene are associated with increased susceptibility to systemic lupus erythematosus (SLE) and concomitant infections.......To determine whether variant alleles in the coding portion of the mannose-binding lectin (MBL) gene are associated with increased susceptibility to systemic lupus erythematosus (SLE) and concomitant infections....
Full Text Available Natural Killer (NK cells contribute to the control of viral infection by directly killing target cells and mediating cytokine release. In C57BL/6 mice, the Ly49H activating NK cell receptor plays a key role in early resistance to mouse cytomegalovirus (MCMV infection through specific recognition of the MCMV-encoded MHC class I-like molecule m157 expressed on infected cells. Here we show that transgenic expression of Ly49H failed to provide protection against MCMV infection in the naturally susceptible A/J mouse strain. Characterization of Ly49H(+ NK cells from Ly49h-A transgenic animals showed that they were able to mount a robust cytotoxic response and proliferate to high numbers during the course of infection. However, compared to NK cells from C57BL/6 mice, we observed an intrinsic defect in their ability to produce IFNγ when challenged by either m157-expressing target cells, exogenous cytokines or chemical stimulants. This effect was limited to NK cells as T cells from C57BL/6 and Ly49h-A mice produced comparable cytokine levels. Using a panel of recombinant congenic strains derived from A/J and C57BL/6 progenitors, we mapped the genetic basis of defective IFNγ production to a single 6.6 Mb genetic interval overlapping the Ifng gene on chromosome 10. Inspection of the genetic interval failed to reveal molecular differences between A/J and several mouse strains showing normal IFNγ production. The chromosome 10 locus is independent of MAPK signalling or decreased mRNA stability and linked to MCMV susceptibility. This study highlights the existence of a previously uncovered NK cell-specific cis-regulatory mechanism of Ifnγ transcript expression potentially relevant to NK cell function in health and disease.
Graybill, J R; Najvar, L K; Holmberg, J D; Correa, A.; Luther, M F
A series of fluconazole-susceptible and-fluconazole resistant Candida albicans fungal isolates were used to infect mice intravenously. Mice were treated with varying doses of fluconazole beginning one day after infection. For all of the 6 fluconazole-susceptible isolates, fluconazole was highly effective at or = 40 mg/kg twice daily in 4 fluconazole-resistant isolates. Although the correlation is not precise, in vitro susceptibility testing of C. albicans can predict in vivo response to fluc...
... the burden of infection on man and the prevention and control options can we understand the disease better and so be better prepare for the future management of this disease. Keywords: Plasmodium infection, Malaria, Epidemiology, Symptoms, Treatment, Control, Man Animal Research International Vol. 3 (3) 2006 pp.
Poelma, F G
Pneumocystis carinii was found to be present in the lungs of twenty-three zoo animals in the Netherlands. The following species were represented: red kangaroo, common tree shrew, Senegal-Galago, Demidoff's-Galago, brown howler monkey, woolly monkey, long-haired spider monkey, white-eared marmoset, chimpanzee, three-toed sloth, palm squirrel, red panda, fennec fox, tree hyrax and large-toothed hyrax.
Skjönsberg, Åsa; Mannström, Paula
The German waltzing guinea pig is a spontaneously mutated strain with severe auditory and vestibular impairment caused by a so far unknown genetic mutation. The animals are born deaf and show a circling behavior. The heterozygote animals of this guinea pig strain have functionally normal hearing and balance. However, these animals have, in earlier studies, shown an increased resistance to noise compared with normal wild-type guinea pigs. In the present study, we explored the functional hearing with auditory brainstem response thresholds before and at different time points after noise exposure. Symptom-free littermates from heterozygote couples of the German waltzing guinea pigs were exclusively used for the study, which, after the hearing test, were sent back for breeding to confirm their genotype (i.e. heterozygote or normal). The aim of this paper was to ascertain that the previously shown reduced susceptibility to noise trauma in the heterozygote animals of the German waltzing guinea pig was also evident when littermates were used as control animals. The findings are important for further analysis of the heterozygote animals of this strain and for future investigations of the underlying mechanisms behind the diverse susceptibility to exposures of loud sound.
Varicella zoster virus (VZV) is an occupational hazard for a percentage of health care staff. Nine hundred and seventy staff members attending the Occupational Health Department at Cork University Hospital took part in the survey. A latex agglutination assay was used to determine the health care workers immune status to VZV. Of the 970 workers tested, 928 (95.7%) were immune to VZV. The sensitivity, specificity and predictive value of an enquiry regarding a history of chicken-pox was determined on a sample of 206 health care workers. The positive predictive value was 95% (119\\/125) and the negative predictive value was 11% (4\\/35). The sensitivity of the enquiry was 79% (119\\/150), the specificity was 40% (4\\/10), reducing to 61% (119\\/195) and 36% (4\\/11) respectively when individuals with uncertain histories were included in the calculations. The advantages and disadvantages of selective staff screening are discussed. In the authors\\' opinion all health care workers involved in the clinical care of patients should be screened by serology for past VZV infection before taking up duty and those who are susceptible to VZV should be made aware of the risks and health effects associated with VZV if contracted.
Rodrigo Otávio Silveira Silva
Full Text Available The objective of this study was to evaluate antimicrobial susceptibility in Clostridium difficile strains isolated from animals and humans in Brazil. The 54 C. difficile strains used were isolated from stool samples from piglets (n=16, dogs (n=13, humans (n=13, foals (n=8 calves (n=2, an ocelot (n=1 and a maned wolf (n=1. Antimicrobial susceptibility was determined using the serial plate agar dilution method for penicillin, florfenicol, oxytetracycline, erythromycin, vancomycin, metronidazole and tylosin. The C. difficile strains assessed were susceptible to metronidazole and vancomycin. Florfenicol resistance was rarely observed; 52 (96.4% strains were sensitive to this antimicrobial. Five (9.3%, five (9.3%, 14 (25.9% and 20 (37.0% strains were resistant to oxytetracycline, penicillin, tylosin and erythromycin respectively.
Rosen, L; Shroyer, D A
Five species of colonized Toxorhynchites mosquitoes were compared for relative susceptibility to parenteral infection with the four dengue serotypes and St. Louis and Japanese encephalitis viruses. Tx. amboinensis, Tx. brevipalpis, Tx. rutilus, and Tx. splendens were equally susceptible to infection with the dengue viruses, while Tx. theobaldi was relatively resistant to infection with those viruses. All five mosquito species were equally susceptible to infection with the encephalitis viruses. The intensity of immunofluorescence in head squashes was slightly less in Tx. brevipalpis infected with the dengue viruses as compared to the other three mosquito species susceptible to those viruses. Immunofluorescence was also less in Tx. theobaldi infected with the encephalitis viruses as compared with all the other mosquito species.
Chatterjee, Animesh; Rathore, Anurag; Vidyant, Sanjukta; Kakkar, Kavita; Dhole, Tapan N
A multitude of host genetic factors plays a crucial role in susceptibility to HIV-1 infection and progression to AIDS, which is highly variable among individuals and populations. This review focuses on the chemokine-receptor and chemokine genes, which were extensively studied because of their role as HIV co-receptor or co-receptor competitor and influences the susceptibility to HIV-1 infection and progression to AIDS in HIV-1 infected individuals.
Full Text Available A multitude of host genetic factors plays a crucial role in susceptibility to HIV-1 infection and progression to AIDS, which is highly variable among individuals and populations. This review focuses on the chemokine-receptor and chemokine genes, which were extensively studied because of their role as HIV co-receptor or co-receptor competitor and influences the susceptibility to HIV-1 infection and progression to AIDS in HIV-1 infected individuals.
McDonald, J S; Richard, J L; Anderson, A J
In vitro antimicrobial susceptibility tests were carried out on 48 strains of Prototheca zopfii, an achlorophyllous algae causing refractory mastitis in dairy cows; 27 antimicrobials were evaluated. All strains were susceptible to both myxin and nystatin. In addition, 22 strains were susceptible to amphotericin B, 21 to polymyxin B, and 18 to gentamicin. Only 1 strain was susceptible to kanamycin. All strains were resistant to ampicillin, bacitracin, carbenicillin, cephalothin, chloramphenicol, clotrimazole, cloxacillin, erythromycin, flucytosine, ketoconazole, lincomycin, miconazole, neomycin, nitrofurazone, novobiocin, oleandomycin, penicillin, rifampin, streptomycin, tetracycline, and vancomycin.
Changing environment is a reason, that many saprotrophic fungi became opportunists and in the end also maybe a pathogenic. Host specific adaptation is not so strong among fungi, so there are many common fungal pathogens for people and for animals. Animals suffering from dermatomycosis are well recognize as source of human superficial mycoses. Breeding of different exotic animals such as parrots, various Reptiles and Amphibians, miniature Rodents and keeping them as a pets in the peoples houses, have become more and more popular in the recent years. This article is shortly presenting which animals maybe a potential source of fungal infections for humans. Looking for the other mycoses as systemic mycoses, especially candidiasis or aspergilosis there are no data, which allow excluding sick animals as a source of infection for human, even if those deep mycoses have endogenic reactivation mechanism. Immunocompromised people are in high-risk group when they take care of animals. Another important source of potentially pathogenic, mostly air-born fungi may be animal use in experimental laboratory work. During the experiments is possible that laboratory workers maybe hurt and these animals and their environment, food and house boxes could be the possible source of microorganisms, pathogenic for humans or other animals. Unusual way to inoculate these potentially pathogens into the skin of laboratory personnel may cause granulomatous, local lesions on their hands.
Background: Antibiotic‑resistant Acinetobacter nosocomial infection is a leading problem. It acts as an opportunistic pathogen to cause a wide spectrum of infection including nosocomial pneumonia, meningitis, endocarditis, skin and soft tissue infections, urinary tract infection, conjunctivitis, burn wound infection and ...
Full Text Available Secondary bacterial pneumonias are a frequent complication of influenza and other respiratory viral infections, but the mechanisms underlying viral-induced susceptibility to bacterial infections are poorly understood. In particular, it is unclear whether the host's response against the viral infection, independent of the injury caused by the virus, results in impairment of antibacterial host defense. Here, we sought to determine whether the induction of an "antiviral" immune state using various viral recognition receptor ligands was sufficient to result in decreased ability to combat common bacterial pathogens of the lung. Using a mouse model, animals were administered polyinosine-polycytidylic acid (poly I:C or Toll-like 7 ligand (imiquimod or gardiquimod intranasally, followed by intratracheal challenge with Streptococcus pneumoniae. We found that animals pre-exposed to poly I:C displayed impaired bacterial clearance and increased mortality. Poly I:C-exposed animals also had decreased ability to clear methicillin-resistant Staphylococcus aureus. Furthermore, we showed that activation of Toll-like receptor (TLR3 and Retinoic acid inducible gene (RIG-I/Cardif pathways, which recognize viral nucleic acids in the form of dsRNA, both contribute to poly I:C mediated impairment of bacterial clearance. Finally, we determined that poly I:C administration resulted in significant induction of type I interferons (IFNs, whereas the elimination of type I IFN signaling improved clearance and survival following secondary bacterial pneumonia. Collectively, these results indicate that in the lung, poly I:C administration is sufficient to impair pulmonary host defense against clinically important gram-positive bacterial pathogens, which appears to be mediated by type I IFNs.
Kim, Jong Rhan; Seok, Seung Hyeok; Kim, Dong Jae; Baek, Min-Won; Na, Yi-Rang; Han, Ju-Hee; Kim, Tae-Hyun; Park, Jae-Hak; Turner, Patricia V; Chung, Doo Hyun; Kang, Byeong-Cheol
Currently, murine noroviruses (MNV) are the most prevalent viral pathogens identified in laboratory animal facilities. While several reports exist concerning the prevalence of MNV in North American research facilities, very few reports are available for other parts of the world, including Korea. This study evaluated the prevalence of MNV infection in 745 murine sera collected from 15 animal facilities in Korea by enzyme linked immunosorbent assay (ELISA). Positive cases were subcategorized by murine strain/genetics, housing environments and animal sources. In summary, 6.6% of inbred/outbred mice purchased from commercial vendors were seropositive, 9.6% of in-house colonies were seropositive and 27.0% of genetically modified mice (GMM) were seropositive. Partial gene amplification of fecal isolates from infected animals showed that they were homologous (100%) with MNV-4.
Hamid Mohamed E
Full Text Available Abstract Background Drug therapy is recommended in conjunction with surgery in treatment of actinomycetoma. The specific prescription depends on the type of bacteria (actinomycetoma or fungi (eumycetoma causing the disease and their in vitro antimicrobial susceptibility. Objectives To investigate the antimicrobial susceptibility among isolates of Streptomyces spp. isolated from cases of actinomycetoma in man and animals in Sudan. Methods Streptomyces strains (n = 18 isolated from cases of actinomycetoma were tested in vitro against 15 commonly prescribed antibacterial agents using MIC agar dilution method as per standard guidelines. Results Streptomyces strains isolated from actinomycetoma fall into various phenotypic groups. All of the strains were inhibited by novobiocin (8 μg/mL, gentamycin (8, 32 μg/mL and doxycycline (32 μg/mL. Fusidic acid (64 μg/mL inhibited 94.4% of the strains; bacitracin, streptomycin, cephaloridine, clindamycin, ampicillin, rifampicin and tetracycline (64 μg/mL inhibited between 61.1 and 77.8% of the strains. All strains were found resistant to amphotericin B (64 μg/mL, penicillin (20 μg/mL and sulphamethoxazole (64 μg/mL. Conclusions Saprophytic Streptomyces spp. cause actinomycetoma in man and animal belong to separate phenotypes and have a wide range of susceptibility patterns to antimicrobial agents, which pose a lot of difficulties in selecting effective in vivo treatment for actinomycetoma.
Rebecca M. Shansky
Full Text Available PTSD occurs in only a small fraction of trauma-exposed individuals, but risk is twice as high in women as in men. The neurobiological basis for this discrepancy is not known, but the identification of biological determinants of resilience and susceptibility in each sex could lead to more targeted preventions and treatments. Animal models are a useful tool for dissecting the circuits and mechanisms that underlie the brain's response to stress, but the vast majority of this work has been developed and conducted in males. The limited work that does incorporate female animals is often inconsistent across labs and does not broadly reflect human populations in terms of female susceptibility to PTSD-like behaviors. In this review, we suggest that interpreting male vs. female comparisons in these models be approached carefully, since common behavioral outcome measures may in fact reflect distinct neural processes. Moreover, since the factors that determine resilience and susceptibility are likely at least in part distinct in men and women, models that take a within-sex approach to response variability may be more useful in identifying critical mechanisms for manipulation.
Carlos Augusto de Oliveira Júnior
Full Text Available Clostridium perfringens is a microorganism commonly found in the microbiota of humans and animals and a potential cause of enteric, muscle or nervous diseases. The treatment of these diseases is based on antimicrobial therapy and it is extremely important to know the antimicrobial susceptibility profile of the strains present in the region. The aim of this study was to evaluate the antimicrobial susceptibility of C. perfringens isolated from domestic and wild animals in Brazil against seven different antimicrobials. Forty-one strains from the stool samples of cattle (n = 12, buffalo (n = 2, goat (n = 3, dogs (n = 12 and wild carnivores (n = 12 were examined. The minimum inhibitory concentration was determined by the agar dilution method using Brucella agar supplemented with 5% of sheep blood, 0.1% of vitamin K, 0.1% of hemin and concentrations ranging from 0,25 to 256,0 mg L-1 of the following antibiotics: erythromycin, florfenicol, metronidazole, oxytetracycline, penicillin, tylosin, and vancomycin. All C. perfringens strains were susceptible to florfenicol, metronidazole, penicillin and vancomycin. Two strains (4.9% were resistant to erythromycin and tylosin, while five (12.2% were resistant to oxytetracycline, one of which (2.4% from an ocelot.
Iwatsuki-Horimoto, Kiyoko; Nakajima, Noriko; Shibata, Masatoshi; Takahashi, Kenta; Sato, Yuko; Kiso, Maki; Yamayoshi, Seiya; Ito, Mutsumi; Enya, Satoko; Otake, Masayoshi; Kangawa, Akihisa; da Silva Lopes, Tiago Jose; Ito, Hirotaka; Hasegawa, Hideki; Kawaoka, Yoshihiro
Pigs are considered a mixing vessel for the generation of novel pandemic influenza A viruses through reassortment because of their susceptibility to both avian and human influenza viruses. However, experiments to understand reassortment in pigs in detail have been limited because experiments with regular-sized pigs are difficult to perform. Miniature pigs have been used as an experimental animal model, but they are still large and require relatively large cages for housing. The microminipig is one of the smallest miniature pigs used for experiments. Introduced in 2010, microminipigs weigh around 10 kg at an early stage of maturity (6 to 7 months old) and are easy to handle. To evaluate the microminipig as an animal model for influenza A virus infection, we compared the receptor distribution of 10-week-old male pigs (Yorkshire Large White) and microminipigs. We found that both animals have SAα2,3Gal and SAα2,6Gal in their respiratory tracts, with similar distributions of both receptor types. We further found that the sensitivity of microminipigs to influenza A viruses was the same as that of larger miniature pigs. Our findings indicate that the microminipig could serve as a novel model animal for influenza A virus infection. The microminipig is one of the smallest miniature pigs in the world and is used as an experimental animal model for life science research. In this study, we evaluated the microminipig as a novel animal model for influenza A virus infection. The distribution of influenza virus receptors in the respiratory tract of the microminipig was similar to that of the pig, and the sensitivity of microminipigs to influenza A viruses was the same as that of miniature pigs. Our findings suggest that microminipigs represent a novel animal model for influenza A virus infection. Copyright © 2017 American Society for Microbiology.
Glaser, C A; Angulo, F J; Rooney, J A
A number of animal-associated infections occur in persons infected with the human immunodeficiency virus (HIV), including those due to Toxoplasma gondii, Cryptosporidium, Microsporida, Salmonella, Campylo-bacter, Giardia, Rhodococcus equi, Rochalimaea, and Listeria monocytogenes. Most of these infections, with the exception of those due to Rochalimaea, appear to be acquired by the immunosuppressed individual from sources other than exposure to animals. Drs. Glaser and colleagues review our current understanding of the role of exposure to animals, especially pets, in the natural history of these opportunistic infections. They suggest that the risk of zoonotic transmission is small and offer practical suggestions designed to reduce this low risk. They conclude that the benefits of animal companionship outweigh the risks to patients and that prohibition of pet ownership by individuals infected with HIV is not warranted.
Paital, Biswaranjan; Panda, Sumana Kumari; Hati, Akshaya Kumar; Mohanty, Bobllina; Mohapatra, Manoj Kumar; Kanungo, Shyama; Chainy, Gagan Bihari Nityananda
The world is projected to experience an approximate doubling of atmospheric CO2 concentration in the next decades. Rise in atmospheric CO2 level as one of the most important reasons is expected to contribute to raise the mean global temperature 1.4 °C-5.8 °C by that time. A survey from 128 countries speculates that global warming is primarily due to increase in atmospheric CO2 level that is produced mainly by anthropogenic activities. Exposure of animals to high environmental temperatures is mostly accompanied by unwanted acceleration of certain biochemical pathways in their cells. One of such examples is augmentation in generation of reactive oxygen species (ROS) and subsequent increase in oxidation of lipids, proteins and nucleic acids by ROS. Increase in oxidation of biomolecules leads to a state called as oxidative stress (OS). Finally, the increase in OS condition induces abnormality in physiology of animals under elevated temperature. Exposure of animals to rise in habitat temperature is found to boost the metabolism of animals and a very strong and positive correlation exists between metabolism and levels of ROS and OS. Continuous induction of OS is negatively correlated with survivability and longevity and positively correlated with ageing in animals. Thus, it can be predicted that continuous exposure of animals to acute or gradual rise in habitat temperature due to global warming may induce OS, reduced survivability and longevity in animals in general and poikilotherms in particular. A positive correlation between metabolism and temperature in general and altered O2 consumption at elevated temperature in particular could also increase the risk of experiencing OS in homeotherms. Effects of global warming on longevity of animals through increased risk of protein misfolding and disease susceptibility due to OS as the cause or effects or both also cannot be ignored. Therefore, understanding the physiological impacts of global warming in relation to
Paital, Biswaranjan; Panda, Sumana Kumari; Hati, Akshaya Kumar; Mohanty, Bobllina; Mohapatra, Manoj Kumar; Kanungo, Shyama; Chainy, Gagan Bihari Nityananda
The world is projected to experience an approximate doubling of atmospheric CO2 concentration in the next decades. Rise in atmospheric CO2 level as one of the most important reasons is expected to contribute to raise the mean global temperature 1.4 °C-5.8 °C by that time. A survey from 128 countries speculates that global warming is primarily due to increase in atmospheric CO2 level that is produced mainly by anthropogenic activities. Exposure of animals to high environmental temperatures is mostly accompanied by unwanted acceleration of certain biochemical pathways in their cells. One of such examples is augmentation in generation of reactive oxygen species (ROS) and subsequent increase in oxidation of lipids, proteins and nucleic acids by ROS. Increase in oxidation of biomolecules leads to a state called as oxidative stress (OS). Finally, the increase in OS condition induces abnormality in physiology of animals under elevated temperature. Exposure of animals to rise in habitat temperature is found to boost the metabolism of animals and a very strong and positive correlation exists between metabolism and levels of ROS and OS. Continuous induction of OS is negatively correlated with survivability and longevity and positively correlated with ageing in animals. Thus, it can be predicted that continuous exposure of animals to acute or gradual rise in habitat temperature due to global warming may induce OS, reduced survivability and longevity in animals in general and poikilotherms in particular. A positive correlation between metabolism and temperature in general and altered O2 consumption at elevated temperature in particular could also increase the risk of experiencing OS in homeotherms. Effects of global warming on longevity of animals through increased risk of protein misfolding and disease susceptibility due to OS as the cause or effects or both also cannot be ignored. Therefore, understanding the physiological impacts of global warming in relation to
Ribeiro, M G; Risseti, R M; Bolaños, C A D; Caffaro, K A; de Morais, A C B; Lara, G H B; Zamprogna, T O; Paes, A C; Listoni, F J P; Franco, M M J
Formerly, Arcanobacterium pyogenes was recently renamed Trueperella pyogenes. This opportunistic bacterium is related to miscellaneous pyogenic infections in animals. Most studies involving T. pyogenes are case reports, whereas few surveys have focused the major aspects of T. pyogenes infections involving a case series study design. The aim of this study was to retrospectively evaluate selected epidemiological and clinical aspects, as well as the in vitro antimicrobial susceptibility pattern of 144 cases of T. pyogenes infections among domestic animals from 2002 to 2012. T. pyogenes was isolated from different clinical specimens from cattle, goats, sheep, pigs, horses, dogs, and buffaloes. Correlations were assessed by the Chi-square or Fisher's exact tests. Mastitis (45.1%), abscesses (18.0%), pneumonia (11.1%), and lymphadenitis (9.0%) were the most common clinical manifestations. In addition, the organism was also isolated from other miscellaneous clinical specimens from cases of septicemia, encephalitis, pyometra, prostatitis, orchitis, seminal vesiculitis, pericarditis, and omphalitis. No statistical association was observed between T. pyogenes infections and age, gender, or season across the study. The most effective drugs against the pathogen were florfenicol (99.1%), cefoperazone (96.0%), cephalexin (95.0%), and ceftiofur (94.8%). High resistance rates were observed against trimethoprim-sulfamethoxazole (49.3%), followed by norfloxacin (10.9%) and tetracycline (9.2%). This study highlights the diversity of clinical manifestations and the opportunistic behavior of T. pyogenes infections in domestic animals, with predominance of mastitis, abscesses, pneumonia, and lymphadenitis. It also reinforces the importance of knowing the susceptibility profile before initiating therapy, to improve antimicrobial therapy approaches.
Falagas, M.E; Karamanidou, C; Kastoris, A.C; Karlis, G; Rafailidis, P.I
OBJECTIVE: To perform a systematic review of the literature to assess the possible effect that psychosocial variables may have on the susceptibility and/or outcome of acute respiratory tract infections (ARTIs).METHODS...
Iwatsuki-Horimoto, Kiyoko; Nakajima, Noriko; Ichiko, Yurie; Sakai-Tagawa, Yuko; Noda, Takeshi; Hasegawa, Hideki; Kawaoka, Yoshihiro
Ferrets and mice are frequently used as animal models for influenza research. However, ferrets are demanding in terms of housing space and handling, whereas mice are not naturally susceptible to infection with human influenza A or B viruses. Therefore, prior adaptation of human viruses is required for their use in mice. In addition, there are no mouse-adapted variants of the recent H3N2 viruses, because these viruses do not replicate well in mice. In this study, we investigated the susceptibility of Syrian hamsters to influenza viruses with a view to using the hamster model as an alternative to the mouse model. We found that hamsters are sensitive to influenza viruses, including the recent H3N2 viruses, without adaptation. Although the hamsters did not show weight loss or clinical signs of H3N2 virus infection, we observed pathogenic effects in the respiratory tracts of the infected animals. All of the H3N2 viruses tested replicated in the respiratory organs of the hamsters, and some of them were detected in the nasal washes of infected animals. Moreover, a 2009 pandemic (pdm09) virus and a seasonal H1N1 virus, as well as one of the two H3N2 viruses, but not a type B virus, were transmissible by the airborne route in these hamsters. Hamsters thus have the potential to be a small-animal model for the study of influenza virus infection, including studies of the pathogenicity of H3N2 viruses and other strains, as well as for use in H1N1 virus transmission studies. IMPORTANCE We found that Syrian hamsters are susceptible to human influenza viruses, including the recent H3N2 viruses, without adaptation. We also found that a pdm09 virus and a seasonal H1N1 virus, as well as one of the H3N2 viruses, but not a type B virus tested, are transmitted by the airborne route in these hamsters. Syrian hamsters thus have the potential to be used as a small-animal model for the study of human influenza viruses. Copyright © 2018 American Society for Microbiology.
Kijlstra, A.; Eissen, O.A.; Cornelissen, J.B.W.J.; Munniksma, K.; Eijck, I.A.J.M.; Kortbeek, T.
PURPOSE. Consumption of undercooked pork meat products has been considered a major risk factor for contracting toxoplasmosis in humans. Indoor farming and improved hygiene have drastically reduced Toxoplasma infections in pigs over the past decades. Whether introduction of animal-friendly production
Nobel, le W.E.; Robben, S.R.; Dopfer, D.D.V.; Hendrikx, W.M.; Boersema, J.H.; Fransen, F.; Eysker, M.
Faecal samples from 224 dogs from 23 animal shelters in the Netherlands were examined for endoparasites. In total 20.5% of the faecal sample were positive for helminth and/or protozoa infections. Eggs of Toxocara canis were found in 8.5% of the faecal samples. Other endoparasites found were
Wagenaar, Jaap; Newell, D.G.; Kalupahana, R.S.; Mughini Gras, Lapo
Campylobacteriosis is a frequently diagnosed disease in humans. Most infections are considered food-borne and are caused by Campylobacter jejuni and C. coli. The animal reservoirs of these Campylobacter, and the sources and routes of transmission, are described and discussed. Most warm-blooded
Weingartl, H M; Nfon, C; Kobinger, G
Ebola viruses (EBOV; genus Ebolavirus, family Filoviridae) cause often fatal, hemorrhagic fever in several species of simian primates including human. While fruit bats are considered a natural reservoir, the involvement of other species in the EBOV transmission cycle is unclear, especially for domesticated animals. Dogs and pigs are so far the only domestic animals identified as species that can be infected with EBOV. In 2009 Reston-EBOV was the first EBOV reported to infect swine with indicated transmission to humans; and a survey in Gabon found over 30% seroprevalence for EBOV in dogs during the Ebola outbreak in 2001-2002. While infections in dogs appear to be asymptomatic, pigs experimentally infected with EBOV can develop clinical disease, depending on the virus species and possibly the age of the infected animals. In the experimental settings, pigs can transmit Zaire-Ebola virus to naive pigs and macaques; however, their role during Ebola outbreaks in Africa needs to be clarified. Attempts at virus and antibody detection require as a prerequisite validation of viral RNA and antibody detection methods especially for pigs, as well as the development of a sampling strategy. Significant issues about disease development remain to be resolved for EBOV. Evaluation of current human vaccine candidates or development of veterinary vaccines de novo for EBOV might need to be considered, especially if pigs or dogs are implicated in the transmission of an African species of EBOV to humans.
Kimberly A Kline
Full Text Available The epidemiology and bacteriology of urinary tract infection (UTI varies across the human lifespan, but the reasons for these differences are poorly understood. Using established monomicrobial and polymicrobial murine UTI models caused by uropathogenic Escherichia coli (UPEC and/or Group B Streptococcus (GBS, we demonstrate age and parity as inter-related factors contributing to UTI susceptibility. Young nulliparous animals exhibited 10-100-fold higher bacterial titers compared to older animals. In contrast, multiparity was associated with more severe acute cystitis in older animals compared to age-matched nulliparous controls, particularly in the context of polymicrobial infection where UPEC titers were ∼1000-fold higher in the multiparous compared to the nulliparous host. Multiparity was also associated with significantly increased risk of chronic high titer UPEC cystitis and ascending pyelonephritis. Further evidence is provided that the increased UPEC load in multiparous animals required TLR4-signaling. Together, these data strongly suggest that the experience of childbearing fundamentally and permanently changes the urinary tract and its response to pathogens in a manner that increases susceptibility to severe UTI. Moreover, this murine model provides a system for dissecting these and other lifespan-associated risk factors contributing to severe UTI in at-risk groups.
Marques, Cátia; Gama, Luís Telo; Belas, Adriana
of antimicrobial resistant bacteria causing urinary tract infection (UTI) in companion animals in Europe. The antimicrobial susceptibility of 22 256 bacteria isolated from dogs and cats with UTI was determined. Samples were collected between 2008 and 2013 from 16 laboratories of 14 European countries....... The prevalence of antimicrobial resistance of the most common bacteria was determined for each country individually in the years 2012-2013 and temporal trends of bacteria resistance were established by logistic regression. RESULTS: The aetiology of uropathogenic bacteria differed between dogs and cats. For all...
Antimicrobial susceptibility testing is recommended to determine which antimicrobial agents should be considered for treating a bacterial pathogen. Many bacteria that cause disease in aquatic animals require growth conditions that vary substantially from routine terrestrial pathogens. It has thus ...
Haynes, Laura; Szaba, Frank M.; Eaton, Sheri M.; Kummer, Lawrence W.; Lanthier, Paula A.; Petell, Ashlee H.; Duso, Debra K.; Luo, Deyan; Lin, Jr-Shiuan; Lefebvre, Julie S; Randall, Troy D.; Johnson, Lawrence L.; Kohlmeier, Jacob E.; Woodland, David L.; Smiley, Stephen T.
Influenza causes more than 250,000 deaths annually in the industrialized world and bacterial infections frequently cause secondary illnesses during influenza outbreaks, including pneumonia, bronchitis, sinusitis, and otitis media. Here we demonstrate that cross-reactive immunity to mismatched influenza strains can reduce susceptibility to secondary bacterial infections, even though this fails to prevent influenza infection. Specifically, infecting mice with H3N2 influenza before challenging w...
Wilk, Esther; Pandey, Ashutosh K; Leist, Sarah Rebecca; Hatesuer, Bastian; Preusse, Matthias; Pommerenke, Claudia; Wang, Junxi; Schughart, Klaus
The host response to influenza A infections is strongly influenced by host genetic factors. Animal models of genetically diverse mouse strains are well suited to identify host genes involved in severe pathology, viral replication and immune responses. Here, we have utilized a dual RNAseq approach that allowed us to investigate both viral and host gene expression in the same individual mouse after H1N1 infection. We performed a detailed expression analysis to identify (i) correlations between changes in expression of host and virus genes, (ii) host genes involved in viral replication, and (iii) genes showing differential expression between two mouse strains that strongly differ in resistance to influenza infections. These genes may be key players involved in regulating the differences in pathogenesis and host defense mechanisms after influenza A infections. Expression levels of influenza segments correlated well with the viral load and may thus be used as surrogates for conventional viral load measurements. Furthermore, we investigated the functional role of two genes, Reg3g and Irf7, in knock-out mice and found that deletion of the Irf7 gene renders the host highly susceptible to H1N1 infection. Using RNAseq analysis we identified novel genes important for viral replication or the host defense. This study adds further important knowledge to host-pathogen-interactions and suggests additional candidates that are crucial for host susceptibility or survival during influenza A infections.
Mason, William S
Australian antigen, the envelope protein of hepatitis B virus (HBV), was discovered in 1967 as a prevalent serum antigen in hepatitis B patients. Early electron microscopy (EM) studies showed that this antigen was present in 22-nm particles in patient sera, which were believed to be incomplete virus. Complete virus, much less abundant than the 22-nm particles, was finally visualized in 1970. HBV was soon found to infect chimpanzees, gorillas, orangutans, gibbon apes, and, more recently, tree shrews (Tupaia belangeri) and cynomolgus macaques (Macaca fascicularis). This restricted host range placed limits on the kinds of studies that might be performed to better understand the biology and molecular biology of HBV and to develop antiviral therapies to treat chronic infections. About 10 years after the discovery of HBV, this problem was bypassed with the discovery of viruses related to HBV in woodchucks, ground squirrels, and ducks. Although unlikely animal models, their use revealed the key steps in hepadnavirus replication and in the host response to infection, including the fact that the viral nuclear episome is the ultimate target for immune clearance of transient infections and antiviral therapy of chronic infections. Studies with these and other animal models have also suggested interesting clues into the link between chronic HBV infection and hepatocellular carcinoma. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.
Full Text Available BACKGROUND: Bats receive increasing attention in infectious disease studies, because of their well recognized status as reservoir species for various infectious agents. This is even more important, as bats with their capability of long distance dispersal and complex social structures are unique in the way microbes could be spread by these mammalian species. Nevertheless, infection studies in bats are predominantly limited to the identification of specific pathogens presenting a potential health threat to humans. But the impact of infectious agents on the individual host and their importance on bat mortality is largely unknown and has been neglected in most studies published to date. METHODOLOGY/PRINCIPAL FINDINGS: Between 2002 and 2009, 486 deceased bats of 19 European species (family Vespertilionidae were collected in different geographic regions in Germany. Most animals represented individual cases that have been incidentally found close to roosting sites or near human habitation in urban and urban-like environments. The bat carcasses were subjected to a post-mortem examination and investigated histo-pathologically, bacteriologically and virologically. Trauma and disease represented the most important causes of death in these bats. Comparative analysis of pathological findings and microbiological results show that microbial agents indeed have an impact on bats succumbing to infectious diseases, with fatal bacterial, viral and parasitic infections found in at least 12% of the bats investigated. CONCLUSIONS/SIGNIFICANCE: Our data demonstrate the importance of diseases and infectious agents as cause of death in European bat species. The clear seasonal and individual variations in disease prevalence and infection rates indicate that maternity colonies are more susceptible to infectious agents, underlining the possible important role of host physiology, immunity and roosting behavior as risk factors for infection of bats.
Bandilla, M; Valtonen, E T; Suomalainen, L-R; Aphalo, P J; Hakalahti, T
Rainbow trout, Oncorhynchus mykiss, were infected concomitantly with Argulus coregoni and Flavobacterium columnare and their survival was compared with that of fish infected with either the parasite or the bacterium alone. The mortality of fish challenged with A. coregoni was negligible while infection with F. columnare alone led to significantly lower survival. However, compared with single infections, the mortality was significantly higher and the onset of disease condition was earlier among fish, which were concomitantly infected by A. coregoni and F. columnare. This data presents, for the first time, experimental support for the hypothesis that an ectoparasite infection increases susceptibility of fish to a bacterial pathogen.
Full Text Available Coxiella burnetii, the causative agent of Q fever, is a zoonotic disease with potentially life-threatening complications in humans. Inhalation of low doses of Coxiella bacteria can result in infection of the host alveolar macrophage (AM. However, it is not known whether a subset of AMs within the heterogeneous population of macrophages in the infected lung is particularly susceptible to infection. We have found that lower doses of both phase I and phase II Nine Mile C. burnetii multiply and are less readily cleared from the lungs of mice compared to higher infectious doses. We have additionally identified AM resident within the lung prior to and shortly following infection, opposed to newly recruited monocytes entering the lung during infection, as being most susceptible to infection. These resident cells remain infected up to twelve days after the onset of infection, serving as a permissive niche for the maintenance of bacterial infection. A subset of infected resident AMs undergo a distinguishing phenotypic change during the progression of infection exhibiting an increase in surface integrin CD11b expression and continued expression of the surface integrin CD11c. The low rate of phase I and II Nine Mile C. burnetii growth in murine lungs may be a direct result of the limited size of the susceptible resident AM cell population.
Lionakis, M.S.; Netea, M.G.; Holland, S.M.
A recent surge in newly described inborn errors of immune function-related genes that result in susceptibility to fungal disease has greatly enhanced our understanding of the cellular and molecular basis of antifungal immune responses. Characterization of single-gene defects that predispose to
Gsell, A.S.; De Senerpont Domis, L.N.; Van Donk, E.; Ibelings, B.W.
The cost of parasitism often depends on environmental conditions and host identity. Therefore, variation in the biotic and abiotic environment can have repercussions on both, species-level host-parasite interaction patterns but also on host genotype-specific susceptibility to disease. We exposed
Raaj S Mehta
Full Text Available Children of mothers infected with soil-transmitted helminths (STH may have an increased susceptibility to STH infection.We did a case-control study nested in a birth cohort in Ecuador. Data from 1,004 children aged 7 months to 3 years were analyzed. Cases were defined as children with Ascaris lumbricoides and/or Trichuris trichiura, controls without. Exposure was defined as maternal infection with A. lumbricoides and/or T. trichiura, detected during the third trimester of pregnancy. The analysis was restricted to households with a documented infection to control for infection risk. Children of mothers with STH infections had a greater risk of infection compared to children of uninfected mothers (adjusted OR 2.61, 95% CI: 1.88-3.63, p<0.001. This effect was particularly strong in children of mothers with both STH infections (adjusted OR: 5.91, 95% CI: 3.55-9.81, p<0.001. Newborns of infected mothers had greater levels of plasma IL-10 than those of uninfected mothers (p=0.033, and there was evidence that cord blood IL-10 was increased among newborns who became infected later in childhood (p=0.060.Our data suggest that maternal STH infections increase susceptibility to infection during early childhood, an effect that was associated with elevated IL-10 in cord plasma.
Boccolini, Daniela; Toma, Luciano; Di Luca, Marco; Severini, Francesco; Romi, R; Remoli, Maria Elena; Sabbatucci, Michela; Venturi, Giulietta; Rezza, Giovanni; Fortuna, Claudia
We investigated the susceptibility of an Italian population of Culex pipiens mosquitoes to Zika virus (ZIKV) infection, tested in parallel with Aedes aegypti, as a positive control. We analysed mosquitoes at 0, 3, 7, 10, 14, 20 and 24 days after an infectious blood meal. Viral RNA was detected in the body of Cx. pipiens up to three days post-infection, but not at later time points. Our results indicate that Cx. pipiens is not susceptible to ZIKV infection. This article is copyright of The Authors, 2016.
Enemark, Heidi L.; Bille-Hansen, Vivi; Lind, Peter
, evaluation of therapeutic agents as well as for assessment of differences in the clinical response to isolates of diverse genetic background. In conclusion, it was shown that the CPB-0 isolate was pathogenic to calves and piglets at a dose of 2.5 x 10(5) oocysts, and that the clinical signs could...... of oocysts were seen in all animals infected with the CPB-0 isolate. Clinical signs included depression, inappetence, vomiting (exclusively in the piglets), and death. Histological examination at 17 and 19 days post-infection revealed parasitic stages and microscopic changes primarily restricted to colon...... and rectum. The unintended presence of rotavirus in some of the experimental animals revealed an additive or synergistic effect between rotavirus and C. parvum as indicated by prolonged diarrhoea, increased oocyst shedding, decreased weight gain and elevated levels of serum haptoglobin and serum amyloid...
Wormser, Gary P.; Schwartz, Ira
Summary: Despite resolution of the objective manifestations of Lyme disease after antibiotic treatment, a minority of patients have fatigue, musculoskeletal pain, and/or difficulties with concentration or short-term memory of uncertain etiology; these are called post-Lyme disease symptoms or, in more severe cases, post-Lyme disease syndrome or “chronic Lyme disease.” Several recent studies in which Borrelia burgdorferi-infected animals were treated with antibiotic therapy have demonstrated th...
Full Text Available Pulmonary infections frequently occur following hip fracture surgery in aged patients. However, the underlying reasons are not fully understood. The present study investigates the systemic inflammatory response and pulmonary conditions following hip fracture surgery as a means of identifying risk factors for lung infections using an aged rodent model. Aged, male Sprague-Dawley rats (8 animals per group underwent a sham procedure or hip fracture plus femoral intramedullary pinning. Animals were sacrificed 1, 3, and 7 days after the injury. Markers of systemic inflammation and pulmonary injury were analyzed. Both sham-operated and injured/surgical group animals underwent intratracheal inoculation with Pseudomonas aeruginosa 1, 3, and 7 days after surgery. P. aeruginosa counts in blood and bronchoalveolar lavage (BAL fluid and survival rates were recorded. Serum TNF-α, IL-6, IL-1β, and IL-10 levels and markers of pulmonary injury were significantly increased at 1 and 3 days following hip fracture and surgery. Animals challenged with P. aeruginosa at 1 and 3 days after injury had a significantly decreased survival rate and more P. aeruginosa recovered from blood and BAL fluid. This study shows that hip fracture and surgery in aged rats induced a systemic inflammatory response and lung injury associated with increased susceptibility to infection during the acute phase after injury and surgery.
Crystal W Burke
Full Text Available The parainfluenza viruses (PIVs are highly contagious respiratory paramyxoviruses and a leading cause of lower respiratory tract (LRT disease. Since no vaccines or antivirals exist, non-pharmaceutical interventions are the only means of control for these pathogens. Here we used bioluminescence imaging to visualize the spatial and temporal progression of murine PIV1 (Sendai virus infection in living mice after intranasal inoculation or exposure by contact. A non-attenuated luciferase reporter virus (rSeV-luc(M-F* that expressed high levels of luciferase yet was phenotypically similar to wild-type Sendai virus in vitro and in vivo was generated to allow visualization. After direct intranasal inoculation, we unexpectedly observed that the upper respiratory tract (URT and trachea supported robust infection under conditions that result in little infection or pathology in the lungs including a low inoculum of virus, an attenuated virus, and strains of mice genetically resistant to lung infection. The high permissivity of the URT and trachea to infection resulted in 100% transmission to naïve contact recipients, even after low-dose (70 PFU inoculation of genetically resistant BALB/c donor mice. The timing of transmission was consistent with the timing of high viral titers in the URT and trachea of donor animals but was independent of the levels of infection in the lungs of donors. The data therefore reveals a disconnect between transmissibility, which is associated with infection in the URT, and pathogenesis, which arises from infection in the lungs and the immune response. Natural infection after transmission was universally robust in the URT and trachea yet limited in the lungs, inducing protective immunity without weight loss even in genetically susceptible 129/SvJ mice. Overall, these results reveal a dichotomy between PIV infection in the URT and trachea versus the lungs and define a new model for studies of pathogenesis, development of live
Nenoff, P; Handrick, W; Krüger, C; Vissiennon, T; Wichmann, K; Gräser, Y; Tchernev, G
Dermatomycoses due to contact with pets and livestock frequently affect children and young adults. Zoophilic dermatophytes are the main important causative agents. It has long been known that the often high inflammatory dermatophytoses of the skin and the scalp are caused mostly by Microsporum canis. Due to an absence of an obligation for reporting fungal infections of the skin to the Public Health Office in Germany, an unnoticed but significant change in responsible pathogens has occurred. Today an increasing number of infections due to zoophilic strains of Trichophyton interdigitale (formerly Trichophyton mentagrophytes) and Trichophyton species of Arthroderma benhamiae are found. The latter mentioned dermatophyte is the anamorph species of the teleomorph Arthroderma benhamiae, which originally was isolated in the Far East (Japan). Source of infection of these dermatophytes are small rodents, in particular guinea pigs. These animals are bought in pet shops by the parents of those children who later are affected by the fungal infection. The coincidental purchase of the relevant fungal pathogen is not obvious to the parents. As a consequence, highly contagious dermatophytoses occur, often tinea capitis sometimes with kerion formation. Further dermatophytes should be considered as cause of a zoophilic dermatomycosis. Both Trichophyton verrucosum, the cause of the ringworm in cattle, and Trichophyton erinacei following contact to hedgehogs are worthy of note. Yeasts cannot be ignored as cause of dermatomycosis, especially Malassezia pachydermatis, the only non-lipophilic species within the genus Malassezia, which can be transferred from dog to men. Cryptococcus neoformans also comes from animal sources. The mucous yeast occurs in bird's dropping, and it causes both pulmonary and central nervous system infections, but also primary and secondary cutaneous cryptococcosis in immunocompromised patients (HIV/AIDS) as possible consequence after contact to these animals.
Ribeiro Ana Cláudia
Full Text Available The aim of the present research was to evaluate the potential of Nectomys rattus, the "water rat", to develop Schistosoma mansoni infection. Comparison with N. squamipes was carried out. Both species of rodents were submitted to transcutaneous infection using different infective cercariae loads: 50, 100 or 500. N. rattus showed high susceptibility to S. mansoni, with an infection rate of 71%. Rodents were able to excrete viable eggs of S. mansoni in the feaces during all infection period. For both species, the small intestine, followed by the liver and the large intestine, presented the highest concentration of eggs among the surveyed organs. Infection caused no animal death. Moreover, N. rattus accomplished the parasite's life cycle, by infecting the snails Biomphalaria glabrata and later Mus musculus. These evidences indicate that both N. rattus, as for N. squamipes are potential reservoirs for schistosomiasis in Brazil. Considering the fact that N. rattus and N. squamipes exist in the same natural ecosystems of S. mansoni, we suggest that these rodents must be regarded as influential factors in epidemiology surveys.
Mansfield, Karen L; Hernández-Triana, Luis M; Banyard, Ashley C; Fooks, Anthony R; Johnson, Nicholas
Japanese encephalitis virus (JEV) is a significant cause of neurological disease in humans throughout Asia causing an estimated 70,000 human cases each year with approximately 10,000 fatalities. The virus contains a positive sense RNA genome within a host-derived membrane and is classified within the family Flaviviridae. Like many flaviviruses, it is transmitted by mosquitoes, particularly those of the genus Culex in a natural cycle involving birds and some livestock species. Spill-over into domestic animals results in a spectrum of disease ranging from asymptomatic infection in some species to acute neurological signs in others. The impact of JEV infection is particularly apparent in pigs. Although infection in adult swine does not result in symptomatic disease, it is considered a significant reproductive problem causing abortion, still-birth and birth defects. Infected piglets can display fatal neurological disease. Equines are also infected, resulting in non-specific signs including pyrexia, but occasionally leading to overt neurological disease that in extreme cases can lead to death. Veterinary vaccination is available for both pigs and horses. This review of JEV disease in livestock considers the current diagnostic techniques available for detection of the virus. Options for disease control and prevention within the veterinary sector are discussed. Such measures are critical in breaking the link to zoonotic transmission into the human population where humans are dead-end hosts. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.
von Wissmann, Beatrix; Machila, Noreen; Picozzi, Kim; Fèvre, Eric M.; deC. Bronsvoort, Barend M.; Handel, Ian G.; Welburn, Susan C.
Background Trypanosomiasis is regarded as a constraint on livestock production in Western Kenya where the responsibility for tsetse and trypanosomiasis control has increasingly shifted from the state to the individual livestock owner. To assess the sustainability of these localised control efforts, this study investigates biological and management risk factors associated with trypanosome infections detected by polymerase chain reaction (PCR), in a range of domestic livestock at the local scale in Busia, Kenya. Busia District also remains endemic for human sleeping sickness with sporadic cases of sleeping sickness reported. Results In total, trypanosome infections were detected in 11.9% (329) out of the 2773 livestock sampled in Busia District. Multivariable logistic regression revealed that host species and cattle age affected overall trypanosome infection, with significantly increased odds of infection for cattle older than 18 months, and significantly lower odds of infection in pigs and small ruminants. Different grazing and watering management practices did not affect the odds of trypanosome infection, adjusted by host species. Neither anaemia nor condition score significantly affected the odds of trypanosome infection in cattle. Human infective Trypanosoma brucei rhodesiense were detected in 21.5% of animals infected with T. brucei s.l. (29/135) amounting to 1% (29/2773) of all sampled livestock, with significantly higher odds of T. brucei rhodesiense infections in T. brucei s.l. infected pigs (OR = 4.3, 95%CI 1.5-12.0) than in T. brucei s.l. infected cattle or small ruminants. Conclusions Although cattle are the dominant reservoir of trypanosome infection it is unlikely that targeted treatment of only visibly diseased cattle will achieve sustainable interruption of transmission for either animal infective or zoonotic human infective trypanosomiasis, since most infections were detected in cattle that did not exhibit classical clinical signs of
Full Text Available Group A Streptococcus (GAS is one of the major causes of respiratory tract infections. The objectives of this study were to identify isolates of S. pyogenes obtained from respiratory tract infections, and to assess their susceptibility to several antibiotics. A total of 40 strains were isolated and their susceptibility to 17 antibiotics was tested using a standard disk diffusion method. The minimum inhibitory concentrations (MICs were determined using the E-test. All isolates were sensitive to β-lactam antibiotics including penicillin, amoxicillin, and cephalosporins. Macrolides remain active with the exception of spiramycin, which showed reduced susceptibility. Out of the 40 isolates, 100% of the isolates were resistant to tetracycline. Interestingly, isolates were sensitive to chloramphenicol, teicoplanin, vancomycine, and levofloxacin, providing potential alternative choices of treatment against infections with S. pyogenes.
to influence the rate of AIDS progression in HIV-1 infected individuals. The candidate host genes suspected to influence the rate of progression from HIV to AIDS can be divided into three categories: (i) genes encoding cell-surface receptors or lig- ands for these proteins; (ii) genes within human leukocyte antigens (HLA) that ...
Sandt, Carol H.; Fedorka-Cray, Paula J.; Tewari, Deepanker; Ostroff, Stephen; Joyce, Kevin; M’ikanatha, Nkuchia M.
Salmonellosis is one of the most important foodborne diseases affecting humans. To characterize the relationship between Salmonella causing human infections and their food animal reservoirs, we compared pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility patterns of non-typhoidal Salmonella isolated from ill humans in Pennsylvania and from food animals before retail. Human clinical isolates were received from 2005 through 2011 during routine public health operations in Pennsylvania. Isolates from cattle, chickens, swine and turkeys were recovered during the same period from federally inspected slaughter and processing facilities in the northeastern United States. We found that subtyping Salmonella isolates by PFGE revealed differences in antimicrobial susceptibility patterns and, for human Salmonella, differences in sources and invasiveness that were not evident from serotyping alone. Sixteen of the 20 most common human Salmonella PFGE patterns were identified in Salmonella recovered from food animals. The most common human Salmonella PFGE pattern, Enteritidis pattern JEGX01.0004 (JEGX01.0003ARS), was associated with more cases of invasive salmonellosis than all other patterns. In food animals, this pattern was almost exclusively (99%) found in Salmonella recovered from chickens and was present in poultry meat in every year of the study. Enteritidis pattern JEGX01.0004 (JEGX01.0003ARS) was associated with susceptibility to all antimicrobial agents tested in 94.7% of human and 97.2% of food animal Salmonella isolates. In contrast, multidrug resistance (resistance to three or more classes of antimicrobial agents) was observed in five PFGE patterns. Typhimurium patterns JPXX01.0003 (JPXX01.0003 ARS) and JPXX01.0018 (JPXX01.0002 ARS), considered together, were associated with resistance to five or more classes of antimicrobial agents: ampicillin, chloramphenicol, streptomycin, sulfonamides and tetracycline (ACSSuT), in 92% of human and 80% of food
J. F. Mendes
Full Text Available Abstract Yeast infections have acquired great importance due to increasing frequency in immunocompromised patients or patients undergoing invasive diagnostic and therapeutic techniques, and also because of its high morbidity and mortality. At the same time, it has been seen an increase in the emergence of new pathogenic species difficult to diagnose and treat. The aim of this study was to determine the in vitro susceptibility of 89 yeasts from different sources against the antifungals amphotericin B, voriconazole, fluconazole and flucytosine, using the VITEK® 2 Compact system. The antifungal susceptibility was performed automatically by the Vitek® 2 Compact system. The origin of the yeasts was: Group 1 - microbiota of wild animals (W (26/89, 2 - cow’s milk with subclinical mastitis (M (27/89 and 3 - hospital enviorment (H (36/89. Of the 89 yeasts submitted to the Vitek® 2 test, 25 (20.9% were resistant to fluconazole, 11 (12.36% to amphotericin B, 3 (3.37% to voriconazole, and no sample was resistant to flucytosine. Regarding the minimum inhibitory concentration (MIC, fluconazole showed an MIC between 1 and 64 mg/mL for the three groups, voriconazole had an MIC between 0.12 and 8 mg/mL, amphotericin B had an MIC between 0.25 and 4 mg/mL for group H and group W respectively, between 0.25 and 16 mg/mL for group M and flucytosine had an MIC equal to 1μg/mL for all groups. The yeasts isolated from the H group showed the highest resistance to fluconazole 12/89 (13.49%, followed by group W (7.87% and group M (5.62%. The more resistant group to voriconazole was followed by the M and H groups, the W group showed no resistance to this antifungal. Group H was the least resistant (2.25% to amphotericin.
Cramp, Rebecca L; Reid, Stefanie; Seebacher, Frank; Franklin, Craig E
Levels of UVB radiation (UVB) and mean temperatures have increased substantially over recent decades in many regions of the world. Both stressors independently can compromise immune function, disease resistance and fitness in fish. The impact of UVB can also be exacerbated by interactions with environmental temperatures. In this paper, we test the hypothesis that UVB and temperature act synergistically to influence patterns of energy consumption and susceptibility to disease. We exposed mosquitofish, Gambusia holbrooki, to a factorial design of low and high UVB levels and low (18°C) and high (25°C) temperatures. The combination of high UVB and high temperature interacted synergistically to suppress metabolism and exacerbate infection intensity by the fish pathogen whitespot (Ichtyhophthirius multifiliis). Given the rapid changes in the thermal environment globally, the interaction between UVB and temperatures on energy use and disease resistance could pose significant problems for aquatic animal health in the context of both pre-existing and emerging diseases. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
Full Text Available Although significant epidemiological evidence indicates that cigarette smoke exposure increases the incidence and severity of viral infection, the molecular mechanisms behind the increased susceptibility of the respiratory tract to viral pathogens are unclear. Adenoviruses are non-enveloped DNA viruses and important causative agents of acute respiratory disease. The Coxsackievirus and adenovirus receptor (CAR is the primary receptor for many adenoviruses. We hypothesized that cigarette smoke exposure increases epithelial susceptibility to adenovirus infection by increasing the abundance of apical CAR.Cultured human airway epithelial cells (CaLu-3 were used as a model to investigate the effect of sidestream cigarette smoke (SSS, mainstream cigarette smoke (MSS, or control air exposure on the susceptibility of polarized respiratory epithelia to adenoviral infection. Using a Cultex air-liquid interface exposure system, we have discovered novel differences in epithelial susceptibility between SSS and MSS exposures. SSS exposure upregulates an eight-exon isoform of CAR and increases adenoviral entry from the apical surface whilst MSS exposure is similar to control air exposure. Additionally, the level of cellular glycogen synthase kinase 3β (GSK3β is downregulated by SSS exposure and treatment with a specific GSK3β inhibitor recapitulates the effects of SSS exposure on CAR expression and viral infection.This is the first time that SSS exposure has been shown to directly enhance the susceptibility of a polarized epithelium to infection by a common respiratory viral pathogen. This work provides a novel understanding of the impact of SSS on the burden of respiratory viral infections and may lead to new strategies to alter viral infections. Moreover, since GSK3β inhibitors are under intense clinical investigation as therapeutics for a diverse range of diseases, studies such as these might provide insight to extend the use of clinically relevant
Sharma, Priyanka; Kolawole, Abimbola O; Core, Susan B; Kajon, Adriana E; Excoffon, Katherine J D A
Although significant epidemiological evidence indicates that cigarette smoke exposure increases the incidence and severity of viral infection, the molecular mechanisms behind the increased susceptibility of the respiratory tract to viral pathogens are unclear. Adenoviruses are non-enveloped DNA viruses and important causative agents of acute respiratory disease. The Coxsackievirus and adenovirus receptor (CAR) is the primary receptor for many adenoviruses. We hypothesized that cigarette smoke exposure increases epithelial susceptibility to adenovirus infection by increasing the abundance of apical CAR. Cultured human airway epithelial cells (CaLu-3) were used as a model to investigate the effect of sidestream cigarette smoke (SSS), mainstream cigarette smoke (MSS), or control air exposure on the susceptibility of polarized respiratory epithelia to adenoviral infection. Using a Cultex air-liquid interface exposure system, we have discovered novel differences in epithelial susceptibility between SSS and MSS exposures. SSS exposure upregulates an eight-exon isoform of CAR and increases adenoviral entry from the apical surface whilst MSS exposure is similar to control air exposure. Additionally, the level of cellular glycogen synthase kinase 3β (GSK3β) is downregulated by SSS exposure and treatment with a specific GSK3β inhibitor recapitulates the effects of SSS exposure on CAR expression and viral infection. This is the first time that SSS exposure has been shown to directly enhance the susceptibility of a polarized epithelium to infection by a common respiratory viral pathogen. This work provides a novel understanding of the impact of SSS on the burden of respiratory viral infections and may lead to new strategies to alter viral infections. Moreover, since GSK3β inhibitors are under intense clinical investigation as therapeutics for a diverse range of diseases, studies such as these might provide insight to extend the use of clinically relevant therapeutics and
Copin, Richard; Vitry, Marie-Alice; Hanot Mambres, Delphine; Machelart, Arnaud; De Trez, Carl; Vanderwinden, Jean-Marie; Magez, Stefan; Akira, Shizuo; Ryffel, Bernhard; Carlier, Yves; Letesson, Jean-Jacques; Muraille, Eric
Brucella are facultative intracellular bacteria that chronically infect humans and animals causing brucellosis. Brucella are able to invade and replicate in a broad range of cell lines in vitro, however the cells supporting bacterial growth in vivo are largely unknown. In order to identify these, we used a Brucella melitensis strain stably expressing mCherry fluorescent protein to determine the phenotype of infected cells in spleen and liver, two major sites of B. melitensis growth in mice. In both tissues, the majority of primary infected cells expressed the F4/80 myeloid marker. The peak of infection correlated with granuloma development. These structures were mainly composed of CD11b+ F4/80+ MHC-II+ cells expressing iNOS/NOS2 enzyme. A fraction of these cells also expressed CD11c marker and appeared similar to inflammatory dendritic cells (DCs). Analysis of genetically deficient mice revealed that differentiation of iNOS+ inflammatory DC, granuloma formation and control of bacterial growth were deeply affected by the absence of MyD88, IL-12p35 and IFN-γ molecules. During chronic phase of infection in susceptible mice, we identified a particular subset of DC expressing both CD11c and CD205, serving as a reservoir for the bacteria. Taken together, our results describe the cellular nature of immune effectors involved during Brucella infection and reveal a previously unappreciated role for DC subsets, both as effectors and reservoir cells, in the pathogenesis of brucellosis. PMID:22479178
Full Text Available Pseudomonas aeruginosa is an opportunistic pathogen capable of causing both acute and chronic infections in susceptible hosts. Chronic P. aeruginosa infections are thought to be caused by bacterial biofilms. Biofilms are highly structured, multicellular, microbial communities encased in an extracellular matrix that enable long-term survival in the host. The aim of this research was to develop an animal model that would allow an in vivo study of P. aeruginosa biofilm infections in a Drosophila melanogaster host. At 24 h post oral infection of Drosophila, P. aeruginosa biofilms localized to and were visualized in dissected Drosophila crops. These biofilms had a characteristic aggregate structure and an extracellular matrix composed of DNA and exopolysaccharide. P. aeruginosa cells recovered from in vivo grown biofilms had increased antibiotic resistance relative to planktonically grown cells. In vivo, biofilm formation was dependent on expression of the pel exopolysaccharide genes, as a pelB::lux mutant failed to form biofilms. The pelB::lux mutant was significantly more virulent than PAO1, while a hyperbiofilm strain (PAZHI3 demonstrated significantly less virulence than PAO1, as indicated by survival of infected flies at day 14 postinfection. Biofilm formation, by strains PAO1 and PAZHI3, in the crop was associated with induction of diptericin, cecropin A1 and drosomycin antimicrobial peptide gene expression 24 h postinfection. In contrast, infection with the non-biofilm forming strain pelB::lux resulted in decreased AMP gene expression in the fly. In summary, these results provide novel insights into host-pathogen interactions during P. aeruginosa oral infection of Drosophila and highlight the use of Drosophila as an infection model that permits the study of P. aeruginosa biofilms in vivo.
Fan, Ping-Chin; Chung, Win-Cheng; Lin, Chung-Yung; Wu, Chin-Cheng
The epidemiology of Taenia saginata in some parts of Asia is confusing, in that beef does not appear to be the source of infection. In some areas, beef is either not available or not eaten raw, whereas pork at times is eaten uncooked. In light of this situation, we have exposed pigs and other animals to infection with strains of T. saginata to establish their ability to serve as intermediate hosts. Eggs of Taiwan Taenia, Korea Taenia, Indonesia Taenia, Thailand Taenia, Philippines Taenia, Ethiopia Taenia, and Madagascar Taenia were fed to 83 pigs of three strains: 43 Small-Ear Miniature (SEM), 34 Landrace Small-Ear Miniature (L-SEM), and 6 Duroc-Yorkshire-Landrace (DYL). We also fed the eggs to 10 Holstein calves, 17 Sannean goats, and 4 monkeys (Macaca cyclopis). We succeeded in infecting SEM (infection rate 88%, cysticercus recovery rate 19.1%), L-SEM (83%, 1.1%), and DYL (100%, 0.3%) pigs with Taiwan Taenia; SEM (100%, 1.7%), L-SEM (100%, 5.6%), and DYL (100%, 0.06%) pigs with Korea Taenia; SEM (100%, 22%) and L-SEM (100%, 1.6%) pigs with Indonesia Taenia; SEM (75%, 0.06%) pigs with Thailand Taenia SEM (100%, 11%) pigs with Philippines Taenia; SEM (80%, 0.005%) pigs with Ethiopia Taenia; SEM (100%, 0.2%) pigs with Madagascar Taenia. Holstein calves became infected with Taenia from Taiwan (100%, 1.1%), Korea (100%, 0.03%), Thailand (100%, 0.2%), and the Philippines (100%, 6%); however, the cysticerci of Taenia from Korea, Thailand, and the Philippines were degenerated and/or calcified. Sannean goats became infected with Taenia from Taiwan (33%, 0.01%) and Korea (50%, 0.02%), while monkeys became infected with Taenia from Taiwan (50%, 0.01%). However, the cysticerci were degenerated and/ or calcified. Therefore, these strains of pig seem to be favorable animal models for experimental studies of T. saginata-like tapeworms, with the SEM pig the most favorable.
Full Text Available The epidemiology of Taenia saginata in some parts of Asia is confusing, in that beef does not appear to be the source of infection. In some areas, beef is either not available or not eaten raw, whereas pork at times is eaten uncooked. In light of this situation, we have exposed pigs and other animals to infection with strains of T. saginata to establish their ability to serve as intermediate hosts. Eggs of Taiwan Taenia, Korea Taenia, Indonesia Taenia, Thailand Taenia, Philippines Taenia, Ethiopia Taenia, and Madagascar Taenia were fed to 83 pigs of three strains: 43 Small-Ear Miniature (SEM, 34 Landrace Small-Ear Miniature (L-SEM, and 6 Duroc-Yorkshire-Landrace (DYL. We also fed the eggs to 10 Holstein calves, 17 Sannean goats, and 4 monkeys (Macaca cyclopis. We succeeded in infecting SEM (infection rate 88%, cysticercus recovery rate 19.1%, L-SEM (83%, 1.1%, and DYL (100%, 0.3% pigs with Taiwan Taenia; SEM (100%, 1.7%, L-SEM (100%, 5.6%, and DYL (100%, 0.06% pigs with Korea Taenia; SEM (100%, 22% and L-SEM (100%, 1.6% pigs with Indonesia Taenia; SEM (75%, 0.06% pigs with Thailand Taenia SEM (100%, 11% pigs with Philippines Taenia; SEM (80%, 0.005% pigs with Ethiopia Taenia; SEM (100%, 0.2% pigs with Madagascar Taenia. Holstein calves became infected with Taenia from Taiwan (100%, 1.1%, Korea (100%, 0.03%, Thailand (100%, 0.2%, and the Philippines (100%, 6%; however, the cysticerci of Taenia from Korea, Thailand, and the Philippines were degenerated and/or calcified. Sannean goats became infected with Taenia from Taiwan (33%, 0.01% and Korea (50%, 0.02%, while monkeys became infected with Taenia from Taiwan (50%, 0.01%. However, the cysticerci were degenerated and/or calcified. Therefore, these strains of pig seem to be favorable animal models for experimental studies of T. saginata-like tapeworms, with the SEM pig the most favorable.
Zaria, L T
Dermatophilus congolensis infection (dermatophilosis) is an acute, subacute or chronic skin disease affecting a wide range of species of animals and man. It is world widely distributed but more prevalent in the humid, tropics and subtropics. The disease is now being reviewed in detail. In the present review, the geographical distribution, history and nomenclature, animal hosts affected, aetiological agent and clinical signs of the disease are discussed extensively. Emphasis is also given on the predisposing factors such as rainfall, humidity, ectoparasites etc. under epizootiology. Pathogenesis, pathology, immunology treatment, control and prophylaxis are other areas well covered. The economic importance of the disease is also stressed and a new approach (biological approach) to treatment and control of the disease is being described in this review. It was concluded that in view of the importance of the disease for the increase of livestock and leather production in the tropical and subtropical region especially in Africa, an international centre for dermatophilosis research is highly needed.
Full Text Available Ebola and Marburg hemorrhagic fevers (EHF and MHF are caused by the Filoviridae family, Ebolavirus and Marburgvirus (ebolavirus and marburgvirus, respectively. These severe diseases have high mortality rates in humans. Although EHF and MHF are endemic to sub-Saharan Africa. A novel filovirus, Lloviu virus, which is genetically distinct from ebolavirus and marburgvirus, was recently discovered in Spain where filoviral hemorrhagic fever had never been reported. The virulence of this virus has not been determined. Ebolavirus and marburgvirus are classified as biosafety level-4 (BSL-4 pathogens and Category A agents, for which the US government requires preparedness in case of bioterrorism. Therefore, preventive measures against these viral hemorrhagic fevers should be prepared, not only in disease-endemic regions, but also in disease-free countries. Diagnostics, vaccines, and therapeutics need to be developed, and therefore the establishment of animal models for EHF and MHF is invaluable. Several animal models have been developed for EHF and MHF using nonhuman primates (NHPs and rodents, which are crucial to understand pathophysiology and to develop diagnostics, vaccines, and therapeutics. Rhesus and cynomolgus macaques are representative models of filovirus infection as they exhibit remarkably similar symptoms to those observed in humans. However, the NHP models have practical and ethical problems that limit their experimental use. Furthermore, there are no inbred and genetically manipulated strains of NHP. Rodent models such as mouse, guinea pig, and hamster, have also been developed. However, these rodent models require adaptation of the virus to produce lethal disease and do not mirror all symptoms of human filovirus infection. This review article provides an outline of the clinical features of EHF and MHF in animals, including humans, and discusses how the animal models have been developed to study pathophysiology, vaccines, and therapeutics.
Nakayama, Eri; Saijo, Masayuki
Ebola and Marburg hemorrhagic fevers (EHF and MHF) are caused by the Filoviridae family, Ebolavirus and Marburgvirus (ebolavirus and marburgvirus), respectively. These severe diseases have high mortality rates in humans. Although EHF and MHF are endemic to sub-Saharan Africa. A novel filovirus, Lloviu virus, which is genetically distinct from ebolavirus and marburgvirus, was recently discovered in Spain where filoviral hemorrhagic fever had never been reported. The virulence of this virus has not been determined. Ebolavirus and marburgvirus are classified as biosafety level-4 (BSL-4) pathogens and Category A agents, for which the US government requires preparedness in case of bioterrorism. Therefore, preventive measures against these viral hemorrhagic fevers should be prepared, not only in disease-endemic regions, but also in disease-free countries. Diagnostics, vaccines, and therapeutics need to be developed, and therefore the establishment of animal models for EHF and MHF is invaluable. Several animal models have been developed for EHF and MHF using non-human primates (NHPs) and rodents, which are crucial to understand pathophysiology and to develop diagnostics, vaccines, and therapeutics. Rhesus and cynomolgus macaques are representative models of filovirus infection as they exhibit remarkably similar symptoms to those observed in humans. However, the NHP models have practical and ethical problems that limit their experimental use. Furthermore, there are no inbred and genetically manipulated strains of NHP. Rodent models such as mouse, guinea pig, and hamster, have also been developed. However, these rodent models require adaptation of the virus to produce lethal disease and do not mirror all symptoms of human filovirus infection. This review article provides an outline of the clinical features of EHF and MHF in animals, including humans, and discusses how the animal models have been developed to study pathophysiology, vaccines, and therapeutics. PMID:24046765
Browne, Niall; Surlis, Carla; Maher, Amie; Gallagher, Clair; Carolan, James C; Clynes, Martin; Kavanagh, Kevin
Galleria mellonella larvae are widely used for assessing the virulence of microbial pathogens and for measuring the in vivo activity of antimicrobial agents and produce results comparable to those that can be obtained using mammals. The aim of the work described here was to ascertain the effect of pre-incubation at 15°C for 1, 3, 6 or 10 weeks on the susceptibility of larvae to infection with Candida albicans and Staphylococcus aureus. Larvae infected with C. albicans after 1 week pre-incubation at 15°C showed 73.3 ± 3.3% survival at 24 hours post-infection while those infected after 10 weeks pre-incubation showed 30 ± 3.3% survival (P mellonella larvae are a useful in vivo model system but the duration of the pre-incubation stage significantly affects their susceptibility to microbial pathogens possibly as a result of altered metabolism. PMID:25785635
Giraldo, Daniel; Wilcox, Douglas R; Longnecker, Richard
Herpes simplex virus type 1 (HSV-1) is a highly prevalent human neurotropic pathogen. HSV-1 infection is associated with a variety of diseases ranging from benign orolabial lesions to more serious and even life-threatening conditions such as herpes simplex keratitis and herpes simplex encephalitis (HSE). HSE is a rare occurrence among healthy adult individuals, but newborns are a particularly susceptible population. Type I IFN signaling has been identified as a crucial component of the innate immune response to the control of HSV-1 infection. In this study, we review the contribution of the type I IFN response to controlling HSV-1 infection, and differences in the early host response between adults and newborns that may contribute to the increased susceptibility to infection and central nervous system disease in newborns.
Daniels, C W; Belosevic, M
The activities of four disaccharidases were examined in resistant (C57Bl/6) and susceptible (C3H/HeN) mice during the primary infection with Giardia muris and after challenge with either trophozoite extract or cysts. Significant decreases in lactase, sucrase, trehalase, and maltase activities in C57Bl/6 mice and lactase and sucrase activities in C3H/HeN mice in the anterior 25% of the small intestine were observed on day 10 after infection. The activities of maltase, sucrase, trehalase, and lactase in the jejunum of C3H/HeN mice were significantly reduced after challenge with trophozoite extract, when compared with the uninfected or infected, but not challenged animals. Decreases in enzyme activities of C3H/HeN mice were evident as early as 12 hours after challenge with the extract. The resistant C57Bl/6 mice showed little change in disaccharidase activity after challenge with trophozoite extract. On the other hand, challenge with cysts resulted in a few decreases in disaccharidase activities in both strains of mice: C57Bl/6 mice showed decreases in the duodenum, while disaccharidases of C3H/HeN mice had lower activity more posteriorly. Thus, challenge with parasite antigen results in a more severe disaccharidase deficiency in susceptible hosts when compared with resistant ones.
Full Text Available The objective of this study was to determine whether Bos taurus cattle differ form Bos indicus in their susceptibility to infection with the Muguga stabilate of Theileria parva and in their resistance to the resultant disease. Ten Friesians (B. taurus, ten improved Borans (B. indicus, ten unimproved Borans (B. indicus and ten Zebus (B. indicus born to dams from an East Coast fever (ECF endemic area were inoculated with an infective dose50 dilution of T. parva Muguga stabilate 147. All the animals except one Friesian and one Zebu developed schizont parasitosis. All the improved Borans, nine of the Friesians, eight of the unimproved Borans and six of the Zebus developed a febrile response. Four of the improved Borans, four of the Friesians and three of the unimproved Borans died of theileriosis. No significant difference (P > 0.05 in the prepatent period occurred between the groups, but the Zebus had a significantly shorter duration of schizont parasitosis (P > 0.05 and took a significantly shorter time to recover (P > 0.05 than the other three groups. There was no significant difference in the two parameters between the other three groups. The study showed that three B. indicus breds and a B. taurus breed are equally susceptible to T. parva infection. However, Zebus born to dams from an ECF endemic area showed a better ability to control the course of disease than cattle from ECF free areas.
Yun, Nadezhda E; Seregin, Alexey V; Walker, David H; Popov, Vsevolod L; Walker, Aida G; Smith, Jeanon N; Miller, Milagros; de la Torre, Juan C; Smith, Jennifer K; Borisevich, Viktoriya; Fair, Joseph N; Wauquier, Nadia; Grant, Donald S; Bockarie, Bayon; Bente, Dennis; Paessler, Slobodan
Lassa fever (LF) is a potentially lethal human disease that is caused by the arenavirus Lassa virus (LASV). Annually, around 300,000 infections with up to 10,000 deaths occur in regions of Lassa fever endemicity in West Africa. Here we demonstrate that mice lacking a functional STAT1 pathway are highly susceptible to infection with LASV and develop lethal disease with pathology similar to that reported in humans.
Full Text Available Liver cancer is a sever cancer burden in the world, especially in developing countries. Its late diagnosis and high mortality rate urges early prediction. Hepatocellular carcinoma (HCC is the major histopathological type of liver cancer. Chronic infection with hepatitis B virus (HBV is a well-established risk factor for HCC. On one side, HBV sequence variation may influence the outcome of HBV infection and the development of HCC. At least ten HBV genotypes (A to J are identified. Several HBV genotypes and mutations in pre-S and pre-core/core promoter regions are closely associated with HCC pathogenesis, and have been regarded as biomarkers to predict the occurrence of HCC. On the other side, only a small fraction of chronic hepatitis B patients developed HCC, and some HCC cases were diagnosed with no known predisposing risk factors, suggesting host genetic variations may also play important roles in the carcinogenesis. In this review, we summarized current findings of HBV genotypes and mutations, host genetic variations and their interactions involved in HCC carcinogenesis. Understanding the key viral and host genetic variations is essential for generating effective predictive biomarkers for HCC development.
Full Text Available Objectives: The purpose of this study was to determine an effective antimicrobial therapy ofcausative agents for orofacial abscesses. In order to do that, bacterial strains isolated from patientsamples were identified based on “bacterial fatty acid profiles” and determined the antimicrobialsusceptibilities by using disc diffusion test for aerobic bacteria, and E test for anaerobic bacteria.Materials and Methods: The present study was carried out in 71 patients with a diagnosis oforofacial infections in Oral and Maxillofacial Surgery Clinic of Atatürk University. Aerobic andanaerobic bacteria were isolated from 71 clinical specimens by Microbial Identification Systemand their antibiotic sensitivity was tested. Results: The most frequently isolated species were Streptococcus spp., Staphylococcus spp.and Bacteroides spp. The highest rate of resistance was detected in the aerobic strains againstpenicillin (58.4%, followed by eriythromycin (46.7%, clindamycin (35.1%, tetracycline(32.5%, amoxycillin/clavulonic acid (31.1% and cefazoline (27.3%, respectively. The highestrate of resistance was detected in the anaerobic strains against to penicillin (60%, clindamycin(53.3%, metronidazole (30%, cefoxitin (20% piperacillin/tazobactam (11.6% and imipenem(0.3%, respectively. Conclusions: In order to treat orofacial infections more effectively, and to prevent antimicrobialresistance which has increased recently, antibiotic susceptility tests should be performedroutinely in regions where antibacterial resistance is high like our area.
Mortier, Rienske A R; Barkema, Herman W; De Buck, Jeroen
The primary objectives of paratuberculosis control programs are reducing exposure of calves to Mycobacterium avium subspecies paratuberculosis (MAP), reducing herd infection pressure and regular testing of cattle >36 months of age. Although control programs based on these principles have reduced prevalence of MAP infection in dairy herds, they have generally not eliminated the infection. Recent infection trial(s) have yielded new knowledge regarding diagnostic testing and age- and dose-dependent susceptibility to MAP infection. Calves up to 1 year of age are still susceptible to MAP infection; therefore, control programs should refrain from referring to specific ages with respect to susceptibility and prevention of new infections. Notwithstanding, lesions were more severe when calves were inoculated at 2 weeks versus 1 year of age. Furthermore, a high inoculation dose resulted in more pronounced lesions than a low inoculation dose, especially in young calves. Consequently, keeping infection pressure low should decrease the incidence of new MAP infections and severity of JD in cattle that do acquire the infection. It was also evident that early diagnosis of MAP infection was possible and could improve efficacy of control programs. Although its use will still need to be validated in the field, a combination of antibody ELISA and fecal culture in young stock, in addition to testing cattle >36 months of age when screening a herd for paratuberculosis, was expected to improve detection of dairy cattle infected with MAP. Although calves were inoculated using a standardized method in a controlled environment, there were substantial differences among calves with regards to immune response, shedding and pathology. Therefore, we inferred there were genetic differences in susceptibility. Important insights were derived from experimental infection trials. Therefore, it was expected that these could improve paratuberculosis control programs by reducing severity and incidence of
Renata Tavares Gomes
Full Text Available Methicillin-resistant Staphylococcus aureus has emerged as a pathogen associated with community-acquired infections worldwide. We report the spectrum of community-acquired S. aureus infections and compare the patients infected with methicillin-susceptible or methicillin-resistant strains among patients aged <20 years. Overall, 90 cases of community acquired S. aureus were detected in an 11-year period. Clinical and microbiological data were registered. Fifty-nine (66% patients were male and the median age was two years. The majority (87% of the patients were hospitalized and chronic underlying illnesses were detected in 27 (30% cases. Overall, 34 (37.8% patients had skin/soft tissue infections and 56 (62.2% patients had deep-seated infection. Four (5.1% patients were transferred to the intensive care unit and two (2.6% died. Complications were detected in 17 (18.9% cases, such as pleural effusion (41.2%, osteomyelitis (23.5%, and sepsis (17.6%. Six (6.7% methicillin-resistant strains were detected. Patients infected with methicillin-susceptible or methicillin-resistant strains had similar baseline characteristics and treatment outcomes. Approximately 93% of the cases received systemic antibiotics, out of which 59 (65.5% used oxacillin or cefalotin. Both methicillin-susceptible and methicillin-resistant S. aureus strains resulted in morbidity and death among children in this setting where methicillin-resistant strains are infrequent.
Evidence from animal studies suggests that chlamydiae may persist in the gastrointestinal tract (GI) and be a reservoir for reinfection of the genital tract. We hypothesize that there may be a differential susceptibility of organisms in the GI and genital tracts. To determine the effect of azithromy...
The salmon louse and infectious salmon anemia virus (ISAv) are the two most significant pathogens of concern to the Atlantic salmon (Salmo salar) aquaculture industry. However, the interactions between sea lice and ISAv, as well as the impact of a prior sea lice infection on the susceptibility of th...
Xin, Lijun; Jiang, Tony T; Kinder, Jeremy M; Ertelt, James M; Way, Sing Sing
Aging confers increased susceptibility to common pathogens including influenza A virus. Despite shared vulnerability to infection with advancing age in humans and rodents, the relatively long time required for immune senescence to take hold practically restricts the use of naturally aged mice to investigate aging-induced immunological shifts. Here, we show accelerated aging Lmna(Dhe) mice with spontaneous mutation in the nuclear scaffolding protein, lamin A, replicate infection susceptibility, and substantial immune cell shifts that occur with advancing age. Naturally aged (≥ 20 month) and 2- to 3-month-old Lmna(Dhe) mice share near identically increased influenza A susceptibility compared with age-matched Lmna(WT) control mice. Increased mortality and higher viral burden after influenza infection in Lmna(Dhe) mice parallel reduced accumulation of lung alveolar macrophage cells, systemic expansion of immune suppressive Foxp3⁺ regulatory T cells, and skewed immune dominance among viral-specific CD8⁺T cells similar to the immunological phenotype of naturally aged mice. Thus, aging-induced infection susceptibility and immune senescence are replicated in accelerated aging Lmna(Dhe) mice. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.
Bricarello, P A; Zaros, L G; Coutinho, L L; Rocha, R A; Silva, M B; Kooyman, F N J; De Vries, E; Yatsuda, A P; Amarante, A F T
Cellular and humoral immune response, as well as cytokine gene expression, was assessed in Nelore cattle with different degrees of resistance to Cooperia punctata natural infection. One hundred cattle (male, weaned, 11-12 months old), kept together on pasture, were evaluated. Faecal and blood samples were collected for parasitological and immunological assays. Based on nematode faecal egg counts (FEC) and worm burden, the seven most resistant and the eight most susceptible animals were selected. Tissue samples of the small intestine were collected for histological quantification of inflammatory cells and analysis of cytokine gene expression (IL-2, IL-4, IL-8, IL-12p35, IL-13, TNF-alpha, IFN-gamma, MCP-1, MCP-2, and MUC-1) using real-time RT-PCR. Mucus samples were also collected for IgA levels determination. Serum IgG1 mean levels against C. punctata antigens were higher in the resistant group, but significant differences between groups were only observed 14 days after the beginning of the experiment against infective larvae (L3) and 14 and 84 days against adult antigens. The resistant group also presented higher IgA levels against C. punctata (L3 and adult) antigens with significant difference 14 days after the beginning of the trial (P<0.05). In the small-intestine mucosa, levels of IgA anti-L3 and anti-adult C. punctata were higher in the resistant group, compared with the susceptible group (P<0.05). Gene expression of both T(H)2 cytokines (IL-4 and IL-13) in the resistant group and T(H)1 cytokines (IL-2, IL-12p35, IFN-gamma and MCP-1) in the susceptible group was up-regulated. Such results suggested that immune response to C. punctata was probably mediated by T(H)2 cytokines in the resistant group and by T(H)1 cytokines in the susceptible group.
Full Text Available For centuries morbillivirus infections have had a huge impact on both human beings and animals. Morbilliviruses are highly contagious pathogens that cause some of the most devastating viral diseases of humans and animals world wide. They include measles virus (MV, canine distemper virus (CDV, rinderpest virus (RPV and peste des petits ruminants (PPRV virus. Furthermore, new emerging infectious diseases of morbilliviruses with significant ecological consequences of marine mammals have been discovered in the past decades. Phocid distemper virus (PDV in seals and the cetacean morbillivirus (CMV have been found in dolphins, whales and porpoises. Peste des petits ruminants (PPR is a highly contagious ,infectious , an acute or sub acute viral disease of domestic and wild small ruminants characterized by fever, oculonasal discharges, stomatitis, conjunctivitis, gastroenteritis and pneumonia. Goats are more severely affected than sheep. It is also known as pseudorinderpest of small ruminants, pest of small ruminants, pest of sheep and goats, kata, stomatitis- pneumoentritis syndrome, contagious pustular stomatitis and pneumoentritis complex. It is one of the major notifiable diseases of the World Organization for Animal Health (OIE. [Vet. World 2009; 2(4.000: 150-155
Full Text Available Arenaviruses are enveloped, bipartite negative single-stranded RNA viruses that can cause a wide spectrum of disease in humans and experimental animals including hemorrhagic fever. The majority of these viruses are rodent-borne and the arenavirus family can be divided into two groups: the Lassa-Lymphocytic choriomeningitis serocomplex and the Tacaribe serocomplex. Arenavirus-induced disease may include characteristic symptoms ranging from fever, malaise, body aches, petechiae, dehydration, hemorrhage, organ failure, shock, and in severe cases death. Currently, there are few prophylactic and therapeutic treatments available for arenavirus-induced symptoms. Supportive care and ribavirin remain the predominant strategies for treating most of the arenavirus-induced diseases. Therefore, efficacy testing of novel therapeutic and prophylactic strategies in relevant animal models is necessary. Because of the potential for person-to-person spread, the ability to cause lethal or debilitating disease in humans, limited treatment options, and potential as a bio-weapon, the development of prophylactics and therapeutics is essential. This article reviews the current arenavirus animal models and prophylactic and therapeutic strategies under development to treat arenavirus infection.
Seyedeh F. Afzali
Full Text Available Aim: Epizootic ulcerative syndrome (EUS causes by aquatic oomycete fungus, Aphanomyces invadans is a dangerous fish disease of a wide range of fresh and brackish water, wild and farmed fish throughout the world. The objective of the present study was to determine the susceptibility of a number of tropical fish species to the EUS and compare the severity of infection between experimental groups. Materials and Methods: Snakehead, Channa striata (Bloch, 1793; snakeskin gourami, Trichopodus pectoralis (Regan, 1910; koi carp, Cyprinus carpio (Linnaeus, 1758; broadhead catfish, Clarias macrocephalus (Günther, 1864; goldfish, Carassius auratus (Linnaeus, 1758; climbing perch, Anabas testudineus (Bloch, 1792; and Nile tilapia, Oreochromis niloticus (Linnaeus, 1758 were challenged by intramuscular injection using zoospores of Aphanomyces invadans (NJM9701. The infected fish skins and muscles were examined for EUS histopathological characteristics, and the results on the severity of lesions and mortality were analyzed using SPSS program. Results: All zoospore-injected fish were shown to be susceptible to the EUS infection except Nile tilapia. Although, the general histopathological pattern was similar in the zoospore-injected group, but there were some variation in granulomatous reaction, that is the presence or absence of giant cells, and time of mortality were detected. The result of statistical analysis showed that there was a significant difference between species, (c2=145.11 and p<0.01. Conclusion: Gourami, koi carp, and catfish were demonstrated to be highly susceptible while goldfish and climbing perch were found to be moderately susceptible to the EUS infection. These findings suggested that the cellular response of fish to mycotic infection and granulomatous reaction varied in different fish species, which could not be an indicator of susceptibility or resistant to the EUS itself, although it was shown that the granulation rate and the level of
Liu, Shan; Zhang, Qionghua; Zhou, Junhua; Yu, Shouyi; Zheng, Xueli; Chen, Qing
To evaluate the susceptibility of Aedes albopictus and Culex pipiens quinquefasciatus to oral infection with bat Japanese encephalitis virus isolates (GD1 and HN2 strains). Aedes albopictus and Culex pipiens quinquefasciatus were infected orally by GD1 and HN2 strains of bat Japanese encephalitis virus. TaqMan real-time PCR was used to detect the virus and monitor the changes in the viral loads in Aedes albopictus and Culex pipiens quinquefasciatus at a 2-day interval, starting from 4 days till 20 days after the infection. The infected Aedes albopictus and Culex pipiens quinquefasciatus were found positive for the Japanese encephalitis virus from day 4 to day 20. Both Aedes albopictus and Culex pipiens quinquefasciatus were susceptible to infection by GD1 and HN2 strains, but the latter showed a greater susceptibility. The HN2 strain virus appeared to have a greater virulence than the GD1 strain. Aedes albopictus and Culex pipiens quinquefasciatus can carry GD1 and HN2 strains of bat Japanese encephalitis virus isolates.
Smallbone, Willow; van Oosterhout, Cock; Cable, Jo
Inbreeding can threaten population persistence by reducing disease resistance through the accelerated loss of gene diversity (i.e. heterozygosity). Such inbreeding depression can affect many different fitness-related traits, including survival, reproductive success, and parasite susceptibility. Empirically quantifying the effects of inbreeding on parasite resistance is therefore important for ex-situ conservation of vertebrates. The present study evaluates the disease susceptibility of individuals bred under three different breeding regimes (inbred, crossed with full siblings; control, randomly crossed mating; and fully outbred). Specifically, we examined the relationship between inbreeding coefficient (F-coefficient) and susceptibility to Gyrodactylus turnbulli infection in a live bearing vertebrate, the guppy Poecilia reticulata. Host-breeding regime significantly affected the trajectories of parasite population growth on individual fish. Inbred fish showed significantly higher mean parasite intensity than fish from the control and outbred breeding regimes, and in addition, inbred fish were slower in purging their gyrodactylid infections. We discuss the role of inbreeding on the various arms of the immune system, and argue that the increased disease susceptibility of inbred individuals could contribute to the extinction vortex. This is one of the first studies to quantify the effects of inbreeding and breeding regime on disease susceptibility in a captive bred vertebrate of wild origin, and it highlights the risks faced by small (captive-bred) populations when exposed to their native parasites. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
Temple, Bradley L; Finger, John W; Jones, Cheryl A; Gabbard, Jon D; Jelesijevic, Tomislav; Uhl, Elizabeth W; Hogan, Robert J; Glenn, Travis C; Tompkins, S Mark
Avian influenza has emerged as one of the most ubiquitous viruses within our biosphere. Wild aquatic birds are believed to be the primary reservoir of all influenza viruses; however, the spillover of H5N1 highly pathogenic avian influenza (HPAI) and the recent swine-origin pandemic H1N1 viruses have sparked increased interest in identifying and understanding which and how many species can be infected. Moreover, novel influenza virus sequences were recently isolated from New World bats. Crocodilians have a slow rate of molecular evolution and are the sister group to birds; thus they are a logical reptilian group to explore susceptibility to influenza virus infection and they provide a link between birds and mammals. A primary American alligator (Alligator mississippiensis) cell line, and embryos, were infected with four, low pathogenic avian influenza (LPAI) strains to assess susceptibility to infection. Embryonated alligator eggs supported virus replication, as evidenced by the influenza virus M gene and infectious virus detected in allantoic fluid and by virus antigen staining in embryo tissues. Primary alligator cells were also inoculated with the LPAI viruses and showed susceptibility based upon antigen staining; however, the requirement for trypsin to support replication in cell culture limited replication. To assess influenza virus replication in culture, primary alligator cells were inoculated with H1N1 human influenza or H5N1 HPAI viruses that replicate independent of trypsin. Both viruses replicated efficiently in culture, even at the 30 C temperature preferred by the alligator cells. This research demonstrates the ability of wild-type influenza viruses to infect and replicate within two crocodilian substrates and suggests the need for further research to assess crocodilians as a species potentially susceptible to influenza virus infection.
Alto, Barry W; Lounibos, L Philip; Mores, Christopher N; Reiskind, Michael H
Dengue, the most important human arboviral disease, is transmitted primarily by Aedes aegypti and, to a lesser extent, by Aedes albopictus. The current distributions of these invasive species overlap and are affected by interspecific larval competition in their container habitats. Here we report that competition also enhances dengue infection and dissemination rates in one of these two vector species. We determined the effects of competition on adult A. aegypti and A. albopictus, comparing their susceptibility to infection with a Southeast Asian strain of dengue-2 virus. High levels of intra- or interspecific competition among larvae enhanced the susceptibility of A. albopictus to dengue virus infection and potential for transmission, as indicated by disseminated infections. Doubling the number of competing larvae (A. albopictus or A. aegypti), led to a significant (more than 60%) increase in the proportion of A. albopictus with disseminated dengue-2 infection. Competition-enhanced vector competence appears to result from a reduction in 'barriers' (morphological or physiological) to virus infection and dissemination and may contribute to the importance of A. albopictus in dengue transmission. Similar results for other unrelated arboviruses suggest that larval competition, common in mosquitoes, should be considered in estimates of vector competence for pathogens that infect humans.
Uzal, Francisco A; McClane, Bruce A; Cheung, Jackie K; Theoret, James; Garcia, Jorge P; Moore, Robert J; Rood, Julian I
The most common animal models used to study Clostridium perfringens infections in humans and animals are reviewed here. The classical C. perfringens-mediated histotoxic disease of humans is clostridial myonecrosis or gas gangrene and the use of a mouse myonecrosis model coupled with genetic studies has contributed greatly to our understanding of disease pathogenesis. Similarly, the use of a chicken model has enhanced our understanding of type A-mediated necrotic enteritis in poultry and has led to the identification of NetB as the primary toxin involved in disease. C. perfringens type A food poisoning is a highly prevalent bacterial illness in the USA and elsewhere. Rabbits and mice are the species most commonly used to study the action of enterotoxin, the causative toxin. Other animal models used to study the effect of this toxin are rats, non-human primates, sheep and cattle. In rabbits and mice, CPE produces severe necrosis of the small intestinal epithelium along with fluid accumulation. C. perfringens type D infection has been studied by inoculating epsilon toxin (ETX) intravenously into mice, rats, sheep, goats and cattle, and by intraduodenal inoculation of whole cultures of this microorganism in mice, sheep, goats and cattle. Molecular Koch's postulates have been fulfilled for enterotoxigenic C. perfringens type A in rabbits and mice, for C. perfringens type A necrotic enteritis and gas gangrene in chickens and mice, respectively, for C. perfringens type C in mice, rabbits and goats, and for C. perfringens type D in mice, sheep and goats. Copyright © 2015 Elsevier B.V. All rights reserved.
Cenker, Jennifer J; Stultz, Ryan D; McDonald, David
Macrophages are a target of human immunodeficiency virus type 1 (HIV-1) infection and may serve as an important reservoir of the virus in the body, particularly after depletion of CD4+ T cells in HIV/AIDS. Recently, sterile alpha motif and histidine/aspartic acid domain-containing protein 1 (SAMHD1) was identified as the major restriction factor of HIV-1 infection in myeloid cells. SAMHD1 is targeted for proteolytic degradation by Vpx, a viral protein encoded by HIV-2 and many simian immunodeficiency viruses but not HIV-1. In this study, we assessed SAMHD1 restriction in in vitro differentiated macrophages and in freshly isolated macrophages from the lungs, abdomen, and brain. We found that infection and spread in in vitro cultured monocyte-derived macrophages were highly limited and that Vpx largely relieved the restriction to initial infection, as expected. We observed nearly identical infection and restriction profiles in freshly isolated peripheral blood monocytes, as well as lung (alveolar) and abdominal (peritoneal) macrophages. In contrast, under the same infection conditions, primary brain macrophages (microglia) were highly susceptible to HIV-1 infection despite levels of endogenous SAMHD1 comparable to the other macrophage populations. Addition of Vpx further increased HIV-1 infection under conditions of limiting virus input, and viral spread was robust whether or not SAMHD1 was depleted. These results suggest that HIV-1 infection of peripherally circulating macrophages is effectively restricted by SAMHD1; however, microglia are highly susceptible to infection despite SAMHD1 expression. These data may explain the long-standing observation that HIV-1 infection is often detected in macrophages in the brain, but seldom in other tissues of the body.
Simon C Groen
Full Text Available Plant volatiles play important roles in attraction of certain pollinators and in host location by herbivorous insects. Virus infection induces changes in plant volatile emission profiles, and this can make plants more attractive to insect herbivores, such as aphids, that act as viral vectors. However, it is unknown if virus-induced alterations in volatile production affect plant-pollinator interactions. We found that volatiles emitted by cucumber mosaic virus (CMV-infected tomato (Solanum lycopersicum and Arabidopsis thaliana plants altered the foraging behaviour of bumblebees (Bombus terrestris. Virus-induced quantitative and qualitative changes in blends of volatile organic compounds emitted by tomato plants were identified by gas chromatography-coupled mass spectrometry. Experiments with a CMV mutant unable to express the 2b RNA silencing suppressor protein and with Arabidopsis silencing mutants implicate microRNAs in regulating emission of pollinator-perceivable volatiles. In tomato, CMV infection made plants emit volatiles attractive to bumblebees. Bumblebees pollinate tomato by 'buzzing' (sonicating the flowers, which releases pollen and enhances self-fertilization and seed production as well as pollen export. Without buzz-pollination, CMV infection decreased seed yield, but when flowers of mock-inoculated and CMV-infected plants were buzz-pollinated, the increased seed yield for CMV-infected plants was similar to that for mock-inoculated plants. Increased pollinator preference can potentially increase plant reproductive success in two ways: i as female parents, by increasing the probability that ovules are fertilized; ii as male parents, by increasing pollen export. Mathematical modeling suggested that over a wide range of conditions in the wild, these increases to the number of offspring of infected susceptible plants resulting from increased pollinator preference could outweigh underlying strong selection pressures favoring pathogen
Groen, Simon C; Jiang, Sanjie; Murphy, Alex M; Cunniffe, Nik J; Westwood, Jack H; Davey, Matthew P; Bruce, Toby J A; Caulfield, John C; Furzer, Oliver J; Reed, Alison; Robinson, Sophie I; Miller, Elizabeth; Davis, Christopher N; Pickett, John A; Whitney, Heather M; Glover, Beverley J; Carr, John P
Plant volatiles play important roles in attraction of certain pollinators and in host location by herbivorous insects. Virus infection induces changes in plant volatile emission profiles, and this can make plants more attractive to insect herbivores, such as aphids, that act as viral vectors. However, it is unknown if virus-induced alterations in volatile production affect plant-pollinator interactions. We found that volatiles emitted by cucumber mosaic virus (CMV)-infected tomato (Solanum lycopersicum) and Arabidopsis thaliana plants altered the foraging behaviour of bumblebees (Bombus terrestris). Virus-induced quantitative and qualitative changes in blends of volatile organic compounds emitted by tomato plants were identified by gas chromatography-coupled mass spectrometry. Experiments with a CMV mutant unable to express the 2b RNA silencing suppressor protein and with Arabidopsis silencing mutants implicate microRNAs in regulating emission of pollinator-perceivable volatiles. In tomato, CMV infection made plants emit volatiles attractive to bumblebees. Bumblebees pollinate tomato by 'buzzing' (sonicating) the flowers, which releases pollen and enhances self-fertilization and seed production as well as pollen export. Without buzz-pollination, CMV infection decreased seed yield, but when flowers of mock-inoculated and CMV-infected plants were buzz-pollinated, the increased seed yield for CMV-infected plants was similar to that for mock-inoculated plants. Increased pollinator preference can potentially increase plant reproductive success in two ways: i) as female parents, by increasing the probability that ovules are fertilized; ii) as male parents, by increasing pollen export. Mathematical modeling suggested that over a wide range of conditions in the wild, these increases to the number of offspring of infected susceptible plants resulting from increased pollinator preference could outweigh underlying strong selection pressures favoring pathogen resistance
Davey, Matthew P.; Bruce, Toby J. A.; Caulfield, John C.; Furzer, Oliver J.; Reed, Alison; Robinson, Sophie I.; Miller, Elizabeth; Davis, Christopher N.; Pickett, John A.; Whitney, Heather M.; Glover, Beverley J.; Carr, John P.
Plant volatiles play important roles in attraction of certain pollinators and in host location by herbivorous insects. Virus infection induces changes in plant volatile emission profiles, and this can make plants more attractive to insect herbivores, such as aphids, that act as viral vectors. However, it is unknown if virus-induced alterations in volatile production affect plant-pollinator interactions. We found that volatiles emitted by cucumber mosaic virus (CMV)-infected tomato (Solanum lycopersicum) and Arabidopsis thaliana plants altered the foraging behaviour of bumblebees (Bombus terrestris). Virus-induced quantitative and qualitative changes in blends of volatile organic compounds emitted by tomato plants were identified by gas chromatography-coupled mass spectrometry. Experiments with a CMV mutant unable to express the 2b RNA silencing suppressor protein and with Arabidopsis silencing mutants implicate microRNAs in regulating emission of pollinator-perceivable volatiles. In tomato, CMV infection made plants emit volatiles attractive to bumblebees. Bumblebees pollinate tomato by ‘buzzing’ (sonicating) the flowers, which releases pollen and enhances self-fertilization and seed production as well as pollen export. Without buzz-pollination, CMV infection decreased seed yield, but when flowers of mock-inoculated and CMV-infected plants were buzz-pollinated, the increased seed yield for CMV-infected plants was similar to that for mock-inoculated plants. Increased pollinator preference can potentially increase plant reproductive success in two ways: i) as female parents, by increasing the probability that ovules are fertilized; ii) as male parents, by increasing pollen export. Mathematical modeling suggested that over a wide range of conditions in the wild, these increases to the number of offspring of infected susceptible plants resulting from increased pollinator preference could outweigh underlying strong selection pressures favoring pathogen resistance
Gonçalves da Costa, S C; Calabrese, K S; Zaverucha do Valle, T; Lagrange, P H
Inbred strains of mice inoculated with the T cruzi Y strain behaved as susceptible (A/J, C3H/HeN), intermediate (BALB/c) or relatively resistant (C57BL/6) with respect to the magnitude of parasitaemia and mortality rate. C57BL/10 mice were susceptible in relation to parasitaemia but resistant when mortality was analyzed. Infection with T cruzi CL strain presented the same results, except for C57BL/6 which behaved as susceptible mice. Athymic mice of various backgrounds revealed no differences in susceptibility, presenting the same dramatic parasitaemia, tissue colonization pattern and no inflammatory reaction in any of the tissues studied. Infection of euthymic and athymic BALB/c mice elicited the production of parasite-specific antibodies, which reached similar levels on the first 9 days but differed after day 13. Serum transfer experiments in BALB/c mice did not show great differences in parasitaemia but altered T. cruzi polymorphism reducing the slender forms in athymic mice. Histopathology of athymic BALB/c mice showed the same tissue tropism when infected either with T cruzi Y or CL strain.
El-Din, Abdel Hakim Saad; Gawish, Fathiya Ali; Abu El Einin, Hanaa Mohamed; Mansour, Shereen Mahfouz
The presence of immunoreactive interleukin (IL-2), interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) in addition to the citation of mother sporscytes in cephalopodal musculature in the susceptible and resistance Bulinus truncatus the specific intermediate host for the trematode Schistosoma haematobium were investigated,. Using ELISA tests, Results indicated that the concentration of IL-2-like activity in the susceptible and resistant snails decreased significantly after infection then persisted at low levels until the 4th week post exposure (WPE) in susceptible snails, while in resistant snails elevated during the second WPE, and returned to initial level at 3 and 4 WPE. Susceptible snails had low detectable levels of TNF-α and INF-γ like-activity after infection. However, the resistant snails had significant low levels of TNF-α and INF-γ like-activity from 3 WPE until the 4th WPE without any sign of normalization. Histological sections in the head- foot region of susceptible and resistance B. truncatus infected with S. haematobium, mother sporocysts exists from 1 to 7(day post exposure) DPE, in the susceptible snail the mother sporocysts were found as single, multiple and mature types. No mother sporocysts were appear in the lip and mantle of the snail on 2, 5, 7 DPE and on 1-3, 6 DPE respectively. In the resistant snails few mother sporocysts were found in the lip, mantle and tentacles. The results showed that schistosome-resistant Bulinus can be an alternative strategy for the control of schistosomiasis.
Davies, Charlotte E; Rowley, Andrew F
Hematodinium spp. infect over 40 species of crustaceans worldwide, but have not been reported to infect the European lobster, Homarus gammarus. In this study, Hematodinium parasites (a mixture of uni- and multinucleate trophont-like stages) were taken from donor crabs (Cancer pagurus) and injected into juvenile H. gammarus. Juvenile C. pagurus were also injected with the same inoculum. Haemolymph was taken at regular intervals and examined for the presence of Hematodinium using light microscopy and PCR, in two separate experiments of duration 4 and 8months. All lobsters were negative for Hematodinium whilst the C. pagurus challenged became infected. It is concluded that European lobsters are not susceptible to infection with a clade of Hematodinium that infects C. pagurus. Copyright © 2015 Elsevier Inc. All rights reserved.
Full Text Available Abstract Background Norway spruce [Picea abies (L. Karst.] is one of the most important conifer species in Europe. The wood is economically important and infections by wood-rotting fungi cause substantial losses to the industry. The first line of defence in a Norway spruce tree is the bark. It is a very efficient barrier against infection based on its mechanical and chemical properties. Once an injury or an infection is recognized by the tree, induced defences are activated. In this study we examined transcriptional response, using 454-sequencing, and chemical profiles in bark of Norway spruce trees with different susceptibility to Heterobasidion annosum s.l. infection. The aim was to find associations between the transcriptome and chemical profiles to the level of susceptibility to Heterobasidion spp. in Norway spruce genotypes. Results Both terpene and phenol compositions were analysed and at 28 days post inoculation (dpi high levels of 3-carene was produced in response to H. annosum. However, significant patterns relating to inoculation or to genotypes with higher or lower susceptibility could only be found in the phenol fraction. The levels of the flavonoid catechin, which is polymerized into proanthocyanidins (PA, showed a temporal variation; it accumulated between 5 and 15 dpi in response to H. annosum infection in the less susceptible genotypes. The transcriptome data suggested that the accumulation of free catechin was preceded by an induction of genes in the flavonoid and PA biosynthesis pathway such as leucoanthocyanidin reductase. Quantitative PCR analyses verified the induction of genes in the phenylpropanoid and flavonoid pathway. The qPCR data also highlighted genotype-dependent differences in the transcriptional regulation of these pathways. Conclusions The varying dynamics in transcriptional and chemical patterns displayed by the less susceptible genotypes suggest that there is a genotypic variation in successful spruce defence
Background Norway spruce [Picea abies (L.) Karst.] is one of the most important conifer species in Europe. The wood is economically important and infections by wood-rotting fungi cause substantial losses to the industry. The first line of defence in a Norway spruce tree is the bark. It is a very efficient barrier against infection based on its mechanical and chemical properties. Once an injury or an infection is recognized by the tree, induced defences are activated. In this study we examined transcriptional response, using 454-sequencing, and chemical profiles in bark of Norway spruce trees with different susceptibility to Heterobasidion annosum s.l. infection. The aim was to find associations between the transcriptome and chemical profiles to the level of susceptibility to Heterobasidion spp. in Norway spruce genotypes. Results Both terpene and phenol compositions were analysed and at 28 days post inoculation (dpi) high levels of 3-carene was produced in response to H. annosum. However, significant patterns relating to inoculation or to genotypes with higher or lower susceptibility could only be found in the phenol fraction. The levels of the flavonoid catechin, which is polymerized into proanthocyanidins (PA), showed a temporal variation; it accumulated between 5 and 15 dpi in response to H. annosum infection in the less susceptible genotypes. The transcriptome data suggested that the accumulation of free catechin was preceded by an induction of genes in the flavonoid and PA biosynthesis pathway such as leucoanthocyanidin reductase. Quantitative PCR analyses verified the induction of genes in the phenylpropanoid and flavonoid pathway. The qPCR data also highlighted genotype-dependent differences in the transcriptional regulation of these pathways. Conclusions The varying dynamics in transcriptional and chemical patterns displayed by the less susceptible genotypes suggest that there is a genotypic variation in successful spruce defence strategies against
Lachowicz-Scroggins, Marrah E.; Boushey, Homer A.; Finkbeiner, Walter E.; Widdicombe, Jonathan H.
Infection of airway epithelium by rhinovirus is the most common cause of asthma exacerbations. Even in mild asthma, airway epithelium exhibits mucous metaplasia, which increases with increasing severity of the disease. We previously showed that squamous cultures of human airway epithelium manifest rhinoviral infection at levels many times higher than in well-differentiated cultures of a mucociliary phenotype. Here we tested the hypothesis that mucous metaplasia is also associated with increased levels of rhinoviral infection. Mucous metaplasia was induced with IL-13, which doubled the numbers of goblet cells. In both control (mucociliary) and IL-13– treated (mucous metaplastic) cultures, goblet cells were preferentially infected by rhinovirus. IL-13 doubled the numbers of infected cells by increasing the numbers of infected goblet cells. Furthermore, IL-13 increased both the maturity of goblet cells and the probability that a goblet cell would be infected. The infection of cells other than goblet cells was unaltered by IL-13. Treatment with IL-13 did not alter the levels of rhinovirus receptor ICAM-1, nor did the proliferative effects of IL-13 enhance infection, because rhinovirus did not colocalize with dividing cells. However, the induction of mucous metaplasia caused changes in the apical membrane structure, notably a marked decrease in overall ciliation, and an increase in the overall flatness of the apical surface. We conclude that mucous metaplasia in asthma increases the susceptibility of airway epithelium to infection by rhinovirus because of changes in the overall architecture of the apical surface. PMID:20081054
Full Text Available Abstract Background The pig-tailed macaques are the only Old World monkeys known to be susceptible to human immunodeficiency virus type 1 (HIV-1 infection. We have previously reported that the TRIM5-Cyclophilin A (TRIMCyp fusion in pig-tailed macaques (Macaca nemestrina is dysfunctional in restricting HIV-1, which may explain why pig-tailed macaques are susceptible to HIV-1 infection. Similar results have also been reported by other groups. However, according to the current primate taxonomy, the previously reported M. nemestrina are further classified into three species, which all belong to the Macaca spp. This calls for the need to look into the previous studies in more details. Results The local species Northern pig-tailed macaque (M. leonina was analyzed for the correlation of TRIM5 structure and HIV-1 infection. Eleven M. leonina animals were analyzed, and all of them were found to possess TRIM5-CypA fusion at the TRIM5 locus. The transcripts encoding the dysfunctional TRIM5-CypA should result from the G-to-T mutation in the 3'-splicing site of intron 6. Polymorphism in the putative TRIMCyp recognition domain was observed. The peripheral blood mononuclear cells (PBMCs of M. leonina were susceptible to HIV-1 infection. Consistent with the previous results, expression of the M. leonina TRIMCyp in HeLa-T4 cells rendered the cells resistant to HIV-2ROD but not to SIVmac239 infection. Conclusion The susceptibility of M. leonina to HIV-1 infection is due to the dysfunctional TRIM5-CypA fusion in the TRIM5 locus. This finding should broaden our perspective in developing better HIV/AIDS non-human primate animal models.
Cardeti, Giusy; Mariano, Valeria; Eleni, Claudia; Aloisi, Marco; Grifoni, Goffredo; Sittinieri, Stefania; Dante, Giampiero; Antognetti, Valeria; Foglia, Efrem Alessandro; Cersini, Antonella; Nardi, Alberigo
The Encephalomyocarditis virus (EMCV) is a small, non enveloped, positive sense single-stranded RNA virus in the genus Cardiovirus, family Picornaviridae, with two known serotypes. It is spread worldwide and infects a huge range of vertebrate hosts with zoonotic potential for humans. The pig is the mammal most likely to be impacted on with the disease, but EMCV occurrence has also been reported in non-human primates and in a variety of domestic, captive and wild animals. Until now, human cases have been very rare and the risk appears to be almost negligible in spite of human susceptibility to the infection. Between September and November 2012 a fatal Encephalomyocarditis virus outbreak involving four Barbary macaques and 24 crested porcupines occurred at a rescue centre for wild and exotic animals in Central Italy. In this open-field zoo park located near Grosseto, Tuscany about 1000 animals belonging to different species, including various non-human primates were hosted at that time. Sudden deaths were generally observed without any evident symptoms or only with mild nonspecific clinical signs. The major gross change was characterised by grey-white necrotic foci in the myocardium and the same EMCV strain was isolated both in macaques and crested porcupines. Phylogenetic analysis has confirmed that only one EMCV strain is circulating in Italy, capable of infecting different animal species. This report confirms the susceptibility of non-human primates to the EMCV infection and describes the disease in porcupine, a common wild Italian and African species. No human cases were observed, but given the zoonotic potential of EMCV these findings are of importance in the context of animal-human interface.
Cai, Chao-Ran; Guan, Jian-Yue
We study a susceptible-vaccinated--infected--recovered (SVIR) epidemic-spreading model with diversity of infection rate of the individuals. By means of analytical arguments as well as extensive computer simulations, we demonstrate that the heterogeneity in infection rate can either impede or accelerate the epidemic spreading, which depends on the amount of vaccinated individuals introduced in the population as well as the contact pattern among the individuals. Remarkably, as long as the individuals with different capability of acquiring the disease interact with unequal frequency, there always exist a cross point for the fraction of vaccinated, below which the diversity of infection rate hinders the epidemic spreading and above which expedites it. The overall results are robust to the SVIR dynamics defined on different population models; the possible applications of the results are discussed.
Full Text Available The abundance and activity of ectoparasites and its hosts are affected by various abiotic factors, such as climate and other organisms (predators, pathogens and competitors presenting thus multiples forms of association (obligate to facultative, permanent to intermittent and superficial to subcutaneous developed during long co-evolving processes. Ticks are ectoparasites widespread globally and its eco epidemiology are closely related to the environmental conditions. They are obligatory hematophagous ectoparasites and responsible as vectors or reservoirs at the transmission of pathogenic fungi, protozoa, viruses, rickettsia and others bacteria during their feeding process on the hosts. Ticks constitute the second vector group that transmit the major number of pathogens to humans and play a role primary for animals in the process of diseases transmission. Many studies on bioecology of ticks, considering the information related to their population dynamics, to the host and the environment, comes possible the application and efficiency of tick control measures in the prevention programs of vector-borne diseases. In this review were considered some taxonomic, morphological, epidemiological and clinical fundamental aspects related to the tick-borne infections that affect human and animal populations.
Wang, Ya-Fang; Yu, Chun-Keung
Human enterovirus 71 (EV71) has emerged as a neuroinvasive virus that is responsible for several outbreaks in the Asia-Pacific region over the past 15 years. Appropriate animal models are needed to understand EV71 neuropathogenesis better and to facilitate the development of effective vaccines and drugs. Non-human primate models have been used to characterize and evaluate the neurovirulence of EV71 after the early outbreaks in late 1990s. However, these models were not suitable for assessing the neurovirulence level of the virus and were associated with ethical and economic difficulties in terms of broad application. Several strategies have been applied to develop mouse models of EV71 infection, including strategies that employ virus adaption and immunodeficient hosts. Although these mouse models do not closely mimic human disease, they have been applied to determine the pathogenesis of and treatment and prevention of the disease. EV71 receptor-transgenic mouse models have recently been developed and have significantly advanced our understanding of the biological features of the virus and the host-parasite interactions. Overall, each of these models has advantages and disadvantages, and these models are differentially suited for studies of EV71 pathogenesis and/or the pre-clinical testing of antiviral drugs and vaccines. In this paper, we review the characteristics, applications and limitation of these EV71 animal models, including non-human primate and mouse models.
Gonzalez, Amanda; Suvà, Domizio; Dunkel, Nathalie; Nicodème, Jean-Damien; Lomessy, Antoine; Lauper, Nicolas; Rohner, Peter; Hoffmeyer, Pierre; Uçkay, Ilker
In Gustilo grade III open fractures, it remains unknown which demographic or clinical features may be associated with an infection resistant to the administered prophylactic agent, compared to one that is susceptible. This was a retrospective case-control study on patients hospitalized from 2004 to 2009. We identified 310 patients with Gustilo-III open fractures, 36 (12%) of which became infected after a median of ten days. In 26 (72%) of the episodes the pathogen was susceptible to the prophylactic antibiotic agent prescribed upon admission, while in the other ten it was resistant. All antibiotic prophylaxis was intravenous; the median duration of treatment was three days and the median delay between trauma and surgery was one day. In multivariate analysis adjusting for case-mix, only Gustilo-grade-IIIc fractures (vascular lesions) showed tendency to be infected with resistant pathogens (odds ratio 10; 95% confidence interval 1.0-10; p = 0.058). There were no significant differences between cases caused by antibiotic resistant and susceptible pathogen cases in patient's sex, presence of immune suppression, duration and choice of antibiotic prophylaxis, choice of surgical technique or materials, time delay until surgery, use of bone reaming, fracture localization, or presence of compartment syndrome. We were unable to identify any specific clinical parameters associated with infection with antibiotic resistant pathogens in Gustilo-grade III open fractures, other than the severity of the fracture itself. More research is needed to identify patients who might benefit from a broader-spectrum antibiotic prophylaxis.
Kok Loon Wong
Full Text Available Human blood monocytes play a central role in dengue infections and form the majority of virus infected cells in the blood. Human blood monocytes are heterogeneous and divided into CD16(- and CD16(+ subsets. Monocyte subsets play distinct roles during disease, but it is not currently known if monocyte subsets differentially contribute to dengue protection and pathogenesis. Here, we compared the susceptibility and response of the human CD16(- and CD16(+ blood monocyte subsets to primary dengue virus in vitro. We found that both monocyte subsets were equally susceptible to dengue virus (DENV2 NGC, and capable of supporting the initial production of new infective virus particles. Both monocyte subsets produced anti-viral factors, including IFN-α, CXCL10 and TRAIL. However, CD16(+ monocytes were the major producers of inflammatory cytokines and chemokines in response to dengue virus, including IL-1β, TNF-α, IL-6, CCL2, 3 and 4. The susceptibility of both monocyte subsets to infection was increased after IL-4 treatment, but this increase was more profound for the CD16(+ monocyte subset, particularly at early time points after virus exposure. These findings reveal the differential role that monocyte subsets might play during dengue disease.
Full Text Available Mice harboring a mutation in the gene encoding gastric intrinsic factor (Gif, a protein essential for the absorption of vitamin B12/cobalamin (Cbl, have potential as a model to explore the role of vitamins in infection. The levels of Cbl in the blood of Giftm1a/tm1a mutant mice were influenced by the maternal genotype, with offspring born to heterozygous (high Cbl, F1 mothers exhibiting a significantly higher serum Cbl level than those born to homozygous (low Cbl, F2 equivalents. Low Cbl levels correlated with susceptibility to an infectious challenge with Salmonella enterica serovar Typhimurium or Citrobacter rodentium, and this susceptibility phenotype was moderated by Cbl administration. Transcriptional and metabolic profiling revealed that Cbl deficient mice exhibited a bioenergetic shift similar to a metabolic phenomenon commonly found in cancerous cells under hypoxic conditions known as the Warburg effect, with this metabolic effect being exacerbated further by infection. Our findings demonstrate a role for Cbl in bacterial infection, with potential general relevance to dietary deficiency and infection susceptibility.
Agarwal, Mansi; Shiau, Stephanie; Larson, Elaine L
Repeat HAIs among frequently hospitalized patients may be contributing to the high rates of antibiotic resistance seen in gram-negative bacteria (GNB) in hospital settings. This systematic review examines the state of the literature assessing the association between repeat GNB HAIs and changes in antibiotic susceptibility patterns. A systematic search of English language published literature was conducted to identify studies in peer-reviewed journals from 2000 to 2015. Studies must have assessed drug resistance in repeat GNB infections longitudinally at the patient level. Two researchers independently reviewed search results for papers meeting inclusion criteria and extracted data. Risk of bias was assessed using a modified quality assessment tool based on the Checklist for Measuring Study Quality and the Quality Assessment Checklist for Cases Series. From 3385 articles identified in the search, seven met inclusion criteria. Five reported lower antibiotic susceptibility in repeated infections, one found a change but did not specify in which direction, and one reported no change. All studies were of low to average quality. Despite the dearth of studies examining repeat GNB infections, evidence suggests that repeat infections result in lower antibiotic susceptibility among hospitalized patients. Larger scale studies with strong methodology are warranted. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Dagi, Hatice Turk; Findik, Duygu; Senkeles, Cigdem; Arslan, Ugur
In this study, our aim was to identify Candida species isolated from bloodstream infections and to determine their susceptibilities to various antifungal agents to demonstrate the local resistance profiles and to guide empirical treatment for clinicians. Two hundred Candida isolates (95 Candida albicans, 105 non-albicans Candida strains) were included in the study. Candida species were identified by conventional, biochemical and molecular methods. Antifungal susceptibility tests for amphotericin B, fluconazole, voriconazole, posaconazole, caspofungin and anidulafungin were performed with broth microdilution method according to the Clinical and Laboratory Standards Institute M27-A3 document. Of the 200 Candida strains, the most prevalent species were C. albicans (47.5 %), Candida glabrata (18.0 %) and Candida parapsilosis complex (14.0 %). All Candida species except for three (1.5 %) Candida kefyr strains were susceptible to amphotericin B. Only one (2.8 %) C. glabrata was resistant to fluconazole (MIC ≥ 64 μg/ml), and the others (97.2 %) exhibited dose-dependent susceptibility. All species, but C. glabrata strains, were susceptible to fluconazole. Resistance to voriconazole, posaconazole, caspofungin and anidulafungin was not detected in any strain. Candida albicans were susceptible to all antifungal drugs. Three C. kefyr strains were resistant to amphotericin B. Only one C. glabrata was resistant to fluconazole. All the strains were susceptible to voriconazole, posaconazole, caspofungin and anidulafungin. In vitro antifungal susceptibility tests should be performed to select of appropriate and effective antifungal therapy, and monitor the development of resistance.
Waters, Valerie; Ratjen, Felix
Antibiotic therapy for acute pulmonary exacerbations in people with cystic fibrosis is usually chosen based on the results of antimicrobial susceptibility testing of individual drugs. Combination antimicrobial susceptibility testing assesses the efficacy of drug combinations including two or three antibiotics in vitro and can often demonstrate antimicrobial efficacy against bacterial isolates even when individual antibiotics have little or no effect. Therefore, choosing antibiotics based on combination antimicrobial susceptibility testing could potentially improve response to treatment in people with cystic fibrosis with acute exacerbations. This is an updated version of a previously published review. To compare antibiotic therapy based on conventional antimicrobial susceptibility testing to antibiotic therapy based on combination antimicrobial susceptibility testing in the treatment of acute pulmonary exacerbations in people with cystic fibrosis and chronic infection with Pseudomonas aeruginosa. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Cystic Fibrosis Trials Register which comprises of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Date of latest search: 19 December 2016.We also searched ongoing trials registries. Date of latest search: 08 March 2017. Randomised and quasi-randomised controlled studies of antibiotic therapy based on conventional antimicrobial susceptibility testing compared to antibiotic therapy based on combination antimicrobial susceptibility testing in the treatment of acute pulmonary exacerbations in cystic fibrosis due to chronic infection with Pseudomonas aeruginosa. Both authors independently selected studies, assessed their quality and extracted data from eligible studies. Additionally, the authors contacted the study investigators to obtain further information. The search identified one multicentre study
Full Text Available Salmonella enterica and Escherichia coli can inhabit humans and animals from multiple origins. These bacteria are often associated with gastroenteritis in animals, being a frequent cause of resistant zoonotic infections. In fact, bacteria from animals can be transmitted to humans through the food chain and direct contact. In this study, we aimed to assess the antibiotic susceptibility of a collection of S. enterica and E. coli recovered from animals of different sources, performing a genomic comparison of the plasmid-mediated quinolone resistance (PMQR-producing isolates detected.Antibiotic susceptibility testing revealed a high number of non wild-type isolates for fluoroquinolones among S. enterica recovered from poultry isolates. In turn, the frequency of non-wild-type E. coli to nalidixic acid and ciprofloxacin was higher in food-producing animals than in companion or zoo animals. Globally, we detected two qnrS1 and two aac(6’-Ib-cr in E. coli isolates recovered from animals of different origins. The genomic characterization of QnrS1-producing E. coli showed high genomic similarity (O86:H12 and ST2297, although they have been recovered from a healthy turtle dove from a Zoo Park, and from a dog showing symptoms of infection. The qnrS1 gene was encoded in a IncN plasmid, also carrying blaTEM-1-containing Tn3. Isolates harboring aac(6’-Ib-cr were detected in two captive bottlenose dolphins, within a time span of two years. The additional antibiotic resistance genes of the two aac(6’-Ib-cr-positive isolates (blaOXA-1, blaTEM-1, blaCTX-M-15, catB3, aac(3-IIa and tetA were enclosed in IncFIA plasmids that differed in a single transposase and 60 single nucleotide variants. The isolates could be assigned to the same genetic sublineage – ST131 fimH30-Rx (O25:H4, confirming clonal spread. PMQR-producing isolates were associated with symptomatic and asymptomatic hosts, which highlight the aptitude of E. coli to act as silent vehicles, allowing
Clifford, D L; Kazwala, R R; Sadiki, H; Roug, A; Muse, E A; Coppolillo, P C; Mazet, J A K
Mycobacterium bovis, a pathogen of conservation, livestock, and public health concern, was detected in eight species of wildlife inhabiting protected areas bordering endemic livestock grazing lands. We tested tissues from 179 opportunistically sampled hunter-killed, depredation, road-killed, and live-captured wild animals, representing 30 species, in and adjacent to Ruaha National Park in south-central Tanzania. Tissue culture and PCR were used to detect 12 (8.1%) M. bovis-infected animals and 15 (10.1%) animals infected with non-tuberculosis complex mycobacteria. Kirk's dik-dik, vervet monkey, and yellow baboon were confirmed infected for the first time. The M. bovis spoligotype isolated from infected wildlife was identical to local livestock, providing evidence for livestock-wildlife pathogen transmission. Thus we advocate an ecosystem-based approach for bovine tuberculosis management that improves critical ecological functions in protected areas and grazing lands, reduces focal population density build-up along the edges of protected areas, and minimizes ecological stressors that increase animals' susceptibility to bovine tuberculosis.
Partha Pratim Das
Results: From the 59 culture positive HIV seropositive cases, 61 Candida isolates were recovered; Candidaalbicans (n=47, 77.0%, C. dubliniensis (n=9, 14.7%, C. parapsilosis (n=2, 3.2%, C. glabrata (n=2, 3.2%, and C. famata (n=1, 1.6%. Candida colonization in HIV-seropositive individuals was significantly higher than that of HIV-seronegative (control group. Antifungal susceptibility testing revealed (n=6, 9.3% C. albicans isolates resistant to voriconazole and fluconazole by disk-diffusion method whereas no resistance was seen by Fungitest method. Interpretation & conclusions: C. albicans was the commonest Candida species infecting or colonizing HIV seropositive individuals. Oropharyngeal Candida isolates had high level susceptibility to all the major antifungals commonly in use. Increased level of immunosuppression in HIV-seropositives and drug resistance of non-albicans Candida species makes identification and susceptibility testing of Candida species necessary in different geographical areas of the country.
Uddin, Md Hafiz; Li, Shunyu; Bae, Young Mee; Choi, Min-Ho; Hong, Sung-Tae
Mice have shown various susceptibility to infection by Clonorchis sinensis. To compare the intra-specific variation in the host-parasite relationship of C. sinensis, 6 strains of mice (ICR, BALB/c, C57BL/6, DDY, CBA/N, and C3H/HeN) with 3 different haplotypes were evaluated on their susceptibility. The worm recovery rate and immunological responses were observed after 4 and 8 weeks of infection with 30 metacercariae. The highest worm recovery rate was observed as 20.7% in the C3H/HeN strain after 4 weeks of infection along with histopathological changes. The rate was 10.0% in C57BL/6 mice after 8 weeks. ICR, BALB/c, and CBA/N showed elevated levels of IgE at both time points when compared to the rest of the strains. The serum IgG1 and IgG2a levels were elevated in most of the strains; however, the C57BL/6 strain showed a lower level of IgG2a that indicated the IgG1 predominance over IgG2a. The production of IL-4 after concanavalin-A stimulation of splenocytes slightly increased among the mouse strains except C3H/HeN after 4 or 8 weeks of infection, but each strain produced high levels of IFN-γ after 8 weeks, which implied mixed Th1/Th2 responses. ICR, DDY, CBA/N, and C3H/HeN strains showed a significantly increased level of IL-10 after 8 weeks as compared to C57BL/6. All of the strains showed an increased level of IL-13 and suggested fibrotic changes in the mice. In conclusion, mice are insusceptible to infection with C. sinensis; however, the C57BL/6, BALB/c and ICR strains are relatively susceptible after 8 weeks of infection among the six strains. Worm expulsion may be one of the causes of low susceptibility of C3H/HeN mice strain at the 8th week. Elevated IgE, IFN-γ, and IL-13 of infected mice suggest both Th1 and Th2 responses that may be related to the low host susceptibility. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Pedro Henrique Braz Mendonça
Full Text Available Trypanosoma cruzi is an obligatory intracellular protozoan parasite, and it is the etiological agent of Chagas’ disease that is endemic in the Americas. In addition to humans, a wide spectrum of mammals can be infected by T. cruzi, including dogs. Dogs develop acute and chronic disease, similar to human infection. T. cruzi can infect almost all cell types and after cell invasion, the metacyclics trypomastigotes localize in the cytoplasm, where they transform into amastigotes, the replicative form of T. cruzi in mammals. After amastigote multiplication and differentiation, parasites lyse host cells and spread through the body by blood circulation. In this work, we evaluated the in vitro ability of T. cruzi to infect a canine macrophage cell line DH82 compared with RAW264.7, a murine tissue culture macrophage. Our results have shown that the T. cruzi is able to infect, replicate and differentiate in DH82 cell line. We observed that following treatment with LPS and IFN-γ DH82 cells were more resistant to infection and that resistance was not related reactive oxygen species production in our system. In this study, we also found that DH82 cells became more susceptible to T. cruzi infection when cocultured with apoptotic cells. The analysis of cytokine production has showed elevated levels of the TGF-β, IL-10, and TNF-α produced by T. cruzi-infected canine macrophages. Additionally, we demonstrated a reduced expression of the MHC class II and CD80 by infected DH82 cell line.
Shah, Said Nasir; Ullah, Bait; Basit, Abdul; Begum, Asia; Tabassum, Anum; Zafar, Shaista; Saleha, Shamim
Respiratory tract infections (RTIs) are the most common infectious diseases in humans and are the major cause of mortality and morbidity in Pakistan. These infections are the leading causes of consultations in primary care in Pakistan. Therefore, this study was aimed at determining bacterial pathogens of respiratory tract infections and the susceptibility patterns of bacterial isolates to antibiotics. The study was conducted between February, 2013 and March, 2014 in North Waziristan region of Pakistan. Sputum specimens were collected aseptically from 227 patients and cultured on the appropriate bacteriological media. Bacterial isolates were identified by biochemical tests and their antibiotics susceptibility patterns were determined by standard methods. Out of 227, various species of bacteria were isolated from 152 (75%) specimens. The prevalence of bacteria species isolated were as follows Pseudomonas aeruginosa (42.8%), Streptococcus pneumoniae (26.7%), Corynebacterium diphtheria (10.6%), Staphylococcus aureus (5.9%), Proteus vulgaris (4.6%), Micrococcus species (3.3%), Klebsiella pneumoniae (2.6%) and Bacillus species (2.6%). The susceptibility patterns varied among bacterial species depending on the antibiotics. For the susceptibility test 11 commercially available antibiotics against bacterial isolates were used. The results revealed that generally the bacterial isolates were susceptible to gentamicin (80.9%), meropenem (75 %), ceftazidime (62.5%), cefotaxime (57.9%) and ceftriazone (57.9%) and resistant to penicillin (84.9%) and doxycycline (78.9%). The antibiotics gentamicin (100%) meropenem (100%), ceftriaxone (58.5%), ciprofloxacin (60%) trimethoprim (60%), ceftazidime (66.2%) and cefotaxime (64.6%) were observed effective against the P. aeruginosa isolates. The findings of our study provide significant information for empiric therapy of patients with RTIs in North Waziristan region of Pakistan.
Liu, Tingting; Lu, Yi; Gau, Vincent; Liao, Joseph C; Wong, Pak Kin
Rapid pathogen detection and antimicrobial susceptibility testing (AST) are required in diagnosis of acute bacterial infections to determine the appropriate antibiotic treatment. Molecular approaches for AST are often based on the detection of known antibiotic resistance genes. Phenotypic culture analysis requires several days from sample collection to result reporting. Toward rapid diagnosis of bacterial infection in non-traditional healthcare settings, we have developed a rapid AST approach that combines phenotypic culture of bacterial pathogens in physiological samples and electrochemical sensing of bacterial 16S rRNA. The assay determines the susceptibility of pathogens by detecting bacterial growth under various antibiotic conditions. AC electrokinetic fluid motion and Joule heating induced temperature elevation are optimized to enhance the sensor signal and minimize the matrix effect, which improve the overall sensitivity of the assay. The electrokinetics enhanced biosensor directly detects the bacterial pathogens in blood culture without prior purification. Rapid determination of the antibiotic resistance profile of Escherichia coli clinical isolates is demonstrated.
Sohail, Muhammad; Rashid, Abid; Aslam, Bilal; Waseem, Muhammad; Shahid, Muhammad; Akram, Muhammad; Khurshid, Mohsin; Rasool, Muhammad Hidayat
The drug resistant Acinetobacter strains are important causes of nosocomial infections that are difficult to control and treat. This study aimed to determine the antimicrobial susceptibility patterns of Acinetobacter strains isolated from different clinical specimens obtained from patients belonging to different age groups. In total, 716 non-duplicate Acinetobacter isolates were collected from the infected patients admitted to tertiary-care hospitals at Lahore, Pakistan, over a period of 28 months. The Acinetobacter isolates were identified using API 20E, and antimicrobial susceptibility testing was performed and interpreted according to Clinical and Laboratory Standards Institute (CLSI) guidelines. The isolation rate of Acinetobacter was high from the respiratory specimens, followed by wound samples. Antibiotic susceptibility analyses of the isolates revealed that the resistance to cefotaxime and ceftazidime was the most common, in 710 (99.2%) specimens each, followed by the resistance to gentamicin in 670 (93.6%) isolates, and to imipenem in 651 (90.9%) isolates. However, almost all isolates were susceptible to tigecycline, colistin, and polymyxin B. The present study showed the alarming trends of resistance of Acinetobacter strains isolated from clinical specimens to the various classes of antimicrobials. The improvement of microbiological techniques for earlier and more accurate identification of bacteria is necessary for the selection of appropriate treatments.
Full Text Available Abstract: Introduction: The drug resistant Acinetobacter strains are important causes of nosocomial infections that are difficult to control and treat. This study aimed to determine the antimicrobial susceptibility patterns of Acinetobacter strains isolated from different clinical specimens obtained from patients belonging to different age groups. METHODS: In total, 716 non-duplicate Acinetobacter isolates were collected from the infected patients admitted to tertiary-care hospitals at Lahore, Pakistan, over a period of 28 months. The Acinetobacter isolates were identified using API 20E, and antimicrobial susceptibility testing was performed and interpreted according to Clinical and Laboratory Standards Institute (CLSI guidelines. RESULTS: The isolation rate of Acinetobacter was high from the respiratory specimens, followed by wound samples. Antibiotic susceptibility analyses of the isolates revealed that the resistance to cefotaxime and ceftazidime was the most common, in 710 (99.2% specimens each, followed by the resistance to gentamicin in 670 (93.6% isolates, and to imipenem in 651 (90.9% isolates. However, almost all isolates were susceptible to tigecycline, colistin, and polymyxin B. CONCLUSIONS: The present study showed the alarming trends of resistance of Acinetobacter strains isolated from clinical specimens to the various classes of antimicrobials. The improvement of microbiological techniques for earlier and more accurate identification of bacteria is necessary for the selection of appropriate treatments.
Zare, Y; Shook, G E; Collins, M T; Kirkpatrick, B W
Paratuberculosis (Johne's disease), an enteric disorder in ruminants caused by Mycobacterium avium ssp. paratuberculosis, causes economic losses in excess of $200 million annually to the US dairy industry. Costly diagnostic testing, cumbersome control programs, incurability, and ineffective vaccination all make M. avium ssp. paratuberculosis susceptibility a good candidate for genetic studies and genetic selection a potentially useful adjunct to management-based control programs. No report has been published for heritability of susceptibility to M. avium ssp. paratuberculosis infection in Jersey cattle. The objective of this study was to estimate variance components and heritability for susceptibility to M. avium ssp. paratuberculosis infection in US Jersey cattle. Data consisted of complete serum ELISA and partial fecal culture results on a total of 2,861 Jersey cows from 23 commercial herds throughout the United States after editing. Four M. avium ssp. paratuberculosis susceptibility phenotypes were defined using (1) ELISA sample-to-positive ratios as a continuous trait, (2) ELISA results as a binary trait (positive=1, negative=0), (3) ELISA results as an ordered categorical trait, and (4) a combined test in which ELISA and fecal culture results were both taken into account in a binary analysis. Three statistical models, including linear, binary threshold, and ordered threshold sire models, were used to analyze the data. All analyses were executed using the restricted maximum likelihood method in ASReml 3 software. The heritability estimates were low to moderate and ranged from 0.08 (±0.03) to 0.27 (±0.11) based on different trait definitions. The nonzero heritability indicates that susceptibility to M. avium ssp. paratuberculosis infection in Jersey cattle is influenced by genetic factors. Therefore, selection of the least susceptible animals could decrease genetic predisposition to M. avium ssp. paratuberculosis infection in Jersey populations in future
Maria Eugenia Vola
Full Text Available PURPOSE: To study the prevalence of methicillin-resistant Staphylococcus aureus among S. aureus ocular infections in a tertiary health center in Brazil and compare antibiotic susceptibility patterns between MRSA and methicillin-susceptible S. aureus isolates. METHODS: Electronic records from the ocular microbiology laboratory of the Universidade Federal de São Paulo were retrospectively reviewed. During a 10-year period (between January 2000 and December 2009 all conjunctivitis, keratitis, and endophthalmitis cases with a positive culture for S. aureus were identified. Antibiotic susceptibility was determined using the Kirby-Bauer disk diffusion method. RESULTS: Five hundred sixty-six S. aureus isolates were identified; of those, 56 (9.9% were resistant to methicillin. Throughout the 10-year period, Staphylococcus aureus showed a significant increasing trend from 7.55% to 16.18% among overall S. aurues infections (p=0.001 and from 3.7% to 13.16% in conjunctivitis (p=0.001. Conversely, we did not observe the same trend among those with keratitis (p=0.38. Staphylococcus aureus isolates showed higher resistance rates to tobramycin, gentamicin, ciprofloxacin, gatifloxacin, and moxifloxacin when compared with S. aureus isolates (p< 0.001. All cases were susceptible to vancomycin. CONCLUSION: We observed an increasing trend in the overall prevalence of Staphylococcus aureus ocular infections and statistically significant higher resistance rates to commonly used antibiotics compared to Staphylococcus aureus. Our data supports the need for constant bacterial surveillance and should be taken into consideration before initiating empiric treatment of ocular infections.
Pitt, Rachel; Alexander, Sarah; Ison, Catherine; Horner, Patrick; Hathorn, Emma; Goold, Penny; Woodford, Neil; Cole, Michelle J
Antimicrobial susceptibility data for Chlamydia trachomatis are lacking. Methodologies for susceptibility testing in C. trachomatis are not well-defined, standardized or performed routinely owing to its intracellular growth requirements. We sought to develop an assay for the in vitro susceptibility testing of C. trachomatis isolates from two patient cohorts with different clinical outcomes. Twenty-four clinical isolates (11 from persistently infected and 13 from successfully treated patients) were overlaid with media containing two-fold serial dilutions of azithromycin or doxycycline. After incubation, aliquots were removed from the stock inoculum (SI) and each antimicrobial concentration for total RNA extraction, complementary DNA generation and real-time PCR. The MIC was defined as the lowest antimicrobial concentration where a 95% reduction in transcription was evident in comparison with the SI for each isolate. MICs of azithromycin were comparable for isolates from the two patient groups (82% ≤ 0.25 mg/L for persistently infected and 100% ≤ 0.25 mg/L for successfully treated patients). Doxycycline MICs were at least two-fold lower for isolates from the successfully treated patients (53.9% ≤ 0.064 mg/L) than for the persistently infected patients (100% ≥ 0.125 mg/L) (P = 0.006, Fisher's exact test). Overall, 96% of isolates gave reproducible MICs when re-tested. A reproducible assay was developed for antimicrobial susceptibility testing of C. trachomatis. MICs of azithromycin were generally comparable for the two different patient groups. MICs of doxycycline were significantly higher in the persistently infected patients. However, interpretation of elevated MICs in C. trachomatis is extremely challenging in the absence of breakpoints, or wild-type and treatment failure MIC distribution data.
El Damaty, Hend M; Tartor, Yasmine H; Mahmmod, Yasser Saadeldien Ibrahim
Arabian horses, the eldest equine breeds, have great economic and social significance for its long, unique, and storied history. Molecular characterization of dermatophyte species affecting Arabian horses is a crucial necessity for epidemiologic and therapeutic purposes. The objective of this study...... was to identify and differentiate isolates of dermatophytes isolated from naturally infected Arabian horses at species and strains levels using PCR-restriction fragment length polymorphism (RFLP) and DNA sequencing. Additionally, antifungal susceptibility testing using broth microdilution method was performed...
Bello, Olorunjuwon O; Oyekanmi, Edward O; Kelly, Babatunde A; Mebude, Olakunle O; Bello, Temitope K
One of the serious complications associated with diabetes is foot ulcer and this condition affects the quality of life in patients in all classes, races and ages. Chronic wounds are prone to colonization by wide array of microorganisms which could be extremely hazardous to patients if effective and timely therapeutic intervention is not made. This study was conducted to determine the antibiotic susceptibility profiles of bacteria from diabetic foot infections in southwestern Nigeria. Samples ...
Sheath, Danny J; Andreou, Demetra; Britton, J Robert
Predicting how elevated temperatures from climate change alter host-parasite interactions requires understandings of how warming affects host susceptibility and parasite virulence. Here, the effect of elevated water temperature and parasite exposure level was tested on parasite prevalence, abundance and burden, and on fish growth, using Pomphorhynchus laevis and its fish host Squalius cephalus. At 60 days post-exposure, prevalence was higher at the elevated temperature (22 °C) than ambient temperature (18 °C), with infections achieved at considerably lower levels of exposure. Whilst parasite number was significantly higher in infected fish at 22 °C, both mean parasite weight and parasite burden was significantly higher at 18 °C. There were, however, no significant relationships between fish growth rate and temperature, parasite exposure, and the infection parameters. Thus, whilst elevated temperature significantly influenced parasite infection rates, it also impacted parasite development rates, suggesting warming could have complex implications for parasite dynamics and host resistance.
Demirturk, Nese; Demiturk, Nese; Demirdal, Tuna
The aim of this study was to retrospectively investigate nosocomial bloodstream infections (NBI) and their antimicrobial susceptibility patterns at Afyon Kocatepe University (AKU) Hospital, Turkey, from January 2006 to December 2011 and to determine the risk factors for nosocomial BSI. Subjects were aged > or = 18 years. The data were obtained from patient files. Five hundred seventy-nine nosocomial infections in 461 patients were included in the study. Eighty-four point six percent was primary and 15.4% were secondary infections. Gram-positive cocci were the most common organisms. When compared year by year there was an increasing trend in antibacterial resistant gram-negative bacilli. The most common infection risk factors were H2 histamine receptor blocker use and blood transfusions. Regular surveillance of BSI is important to monitor changes in the types of microorganisms and their resistance patterns.
Iman F. Abou-El-Naga
Full Text Available In Egypt, Biomphalaria alexandrina is the intermediate host for Schistosoma mansoni. The fates of Schistosoma miracidia in the snails varies between different species of Biomphalaria. The internal defense system is one of the factors that influence the susceptibility pattern of the snails. The interaction between Biomphalaria snails and S. mansoni needs to be identified for each species, and even between the members of the same species with different degrees of susceptibility. In the present study, the first generation of susceptible and resistant parents of B. alexandrina was examined histologically at the 30th day post exposure. The study includes the characterization of the immune response, as expressed by tissue reactions, of susceptible and resistant B. alexandrina snails against S. mansoni. It was also designed to determine the impact of the resistance increase in parent snails, on the mechanisms of interaction of their offspring against infection. The results showed that the infection rate of the offspring from the susceptible parents was 92%. No susceptible offspring was produced from the resistant parents. When the parents were of equal number of susceptible and resistant snails, they gave an offspring with an infection rate of 20%. Susceptible snails that had susceptible parents showed a higher degree of susceptibility than those that had both susceptible and resistant parents. A common feature of the resistant snails was the absence of any viable parasites. The tissue reactions of the resistant snails having only resistant parents occurred at the site of miracidial penetration. In resistant snails for which susceptible ones were included in their parents, the reactions occurred in the deep tissues. These results characterized the immune response of B. alexandrina snails against Schistosoma infection which was found to occur by two different mechanisms. One type of defense occurs in highly resistant snails, and employs direct
Bustamante, B; Martins, M A; Bonfietti, L X; Szeszs, M W; Jacobs, J; Garcia, C; Melhem, M S C
Yeast identification and in vitro susceptibility testing provide helpful information for appropriate administration of antifungal treatments; however, few reports from the Latin American region have been published. The aim of this study was to identify the species present in isolates from bloodstream infections diagnosed in nine hospitals in Lima, Peru and to determine their in vitro susceptibility to four antifungal drugs. We tested and identified 153 isolates collected between October 2009 and August 2011 using standard methods. PCR and PCR-RFLP assays were performed to distinguish Candida albicans from Candida dubliniensis and to identify species of the Candida parapsilosis and Candida glabrata complexes. Antifungal susceptibility testing for fluconazole, anidulafungin and voriconazole was performed using the CSLI M27-A3 method, and amphotericin B susceptibility was determined using the Etest method. The most frequently isolated species were: C. albicans (61; 39.9 %), C. parapsilosis (43; 28.1 %), C. tropicalis (36; 23.5%) and C. glabrata (8; 5.2 %). The overall susceptibility rates were 98.0 %, 98.7 %, 98.0 % and 97.4 % for amphotericin B, fluconazole, voriconazole and anidulafungin, respectively. No isolate was resistant to more than one drug. These results showed that the rate of resistance to four antifungal drugs was low among Candida bloodstream isolates in Lima, Peru. © 2014 The Authors.
Zhang, Xiaobing; Niu, Siqiang; Zhang, Liping
Pseudomonas aeruginosa is a uropathogen that is mainly involved in nosocomial infection. The aim of this study was to analyze the antimicrobial susceptibilities and clinical characterization of P. aeruginosa isolates from urinary tract infections (UTIs). The study collected all P. aeruginosa UTI strains from a hospital in Chongqing, China, from January 1st, 2010 to December 31st, 2011. The antibiotic susceptibilities of the P. aeruginosa isolates were analyzed using the agar dilution method and the genotypes were assessed using random amplification of polymorphic DNA-PCR (RAPD-PCR). The clinical characteristics of the patients with UTIs were collected from the hospital information systems, and significance was analyzed using the proportion test. A total of 2,778 episodes of culture-proven UTIs were used in the study. There were 198 infections (7.1%) caused by P. aeruginosa. P. aeruginosa strains were highly resistant to most drugs tested. The RAPD-PCR data revealed that the 198 P. aeruginosa infections had 82 different genotypes. Antibacterial use, previous UTI, urinary tract catheter and urinary tract operation were found to be risk factors for the development of UTIs. P. aeruginosa is the second most common UTI pathogen in our hospital. We should closely monitor patients with risk factors for P. aeruginosa infection.
Rodríguez-Lozano, Jesús; de Malet, Ana; Cano, María Eliecer; de la Rubia, Luis; Wallmann, Reinhard; Martínez-Martínez, Luis; Calvo, Jorge
Cumulative susceptibility reports are a valuable tool for the empirical treatment of urinary tract infections, especially in the current context of increasing resistance rates. Our objective was to analyze the antimicrobial susceptibility of bacterial isolates in urine cultures of pediatric patients during a five-year period. Retrospective study of urine cultures from 2011 to 2015. Identification and antimicrobial susceptibility tests were performed using the Vitek-2 system (BioMérieux®) and categorized according to EUCAST criteria. Antimicrobial susceptibility data were analyzed by gender and age groups (neonates, 1 month to 5 years, 5-15 years) before being compared with data obtained from patients over the age of 15 years. During the study period, 17164 urine cultures were processed from 7924 patients under 16 years of age. Antimicrobial susceptibility rates in these patients were: ampicillin 36.3%, amoxicillin/clavulanic acid 75.3%, cefuroxime 83.2%, co-trimoxazole 68.9%, ciprofloxacin 85.3%, fosfomycin 85.5%, nitrofurantoin 84.4% and 3rd generation cephalosporins 89-91%. Aminoglycosides (>92%) and carbapenems (95%) maintained the highest susceptibility rates. The prevalence of ESBL-producing isolates was significantly lower in children under the age of 16 years (1.5% vs. 4.1%). In patients under the age of 16 years, Escherichia coli isolates in girls were significantly more sensitive (p<0.0001) to ampicillin (41% vs. 30%) and amoxicillin/clavulanic acid (82% vs. 72%) than in boys. The compilation of cumulative susceptibility reports disaggregated by age or gender reveals significant differences. In our setting, cefuroxime may be considered the first-line empirical treatment in pediatric patients. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.
Novoa-Farías, O; Frati-Munari, A C; Peredo, M A; Flores-Juárez, S; Novoa-García, O; Galicia-Tapia, J; Romero-Carpio, C E
Bacterial resistance may hamper the antimicrobial management of acute gastroenteritis. Bacterial susceptibility to rifaximin, an antibiotic that achieves high fecal concentrations (up to 8,000μg/g), has not been evaluated in Mexico. To determine the susceptibility to rifaximin and other antimicrobial agents of enteropathogenic bacteria isolated from patients with acute gastroenteritis in Mexico. Bacterial strains were analyzed in stool samples from 1,000 patients with diagnosis of acute gastroenteritis. The susceptibility to rifaximin (RIF) was tested by microdilution (<100, <200, <400 and <800μg/ml) and susceptibility to chloramphenicol (CHL), trimethoprim-sulfamethoxazole (T-S), neomycin (NEO), furazolidone (FUR), fosfomycin (FOS), ampicillin (AMP) and ciprofloxacin (CIP) was tested by agar diffusion at the concentrations recommended by the Clinical & Laboratory Standards Institute and the American Society for Microbiology. Isolated bacteria were: enteropathogenic Escherichia coli (E. coli) (EPEC) 531, Shigella 120, non-Typhi Salmonella 117, Aeromonas spp. 80, enterotoxigenic E. coli (ETEC) 54, Yersinia enterocolitica 20, Campylobacter jejuni 20, Vibrio spp. 20, Plesiomonas shigelloides 20, and enterohemorrhagic E. coli (EHEC 0:157) 18. The overall cumulative susceptibility to RIF at <100, <200, <400, and <800μg/ml was 70.6, 90.8, 99.3, and 100%, respectively. The overall susceptibility to each antibiotic was: AMP 32.2%, T-S 53.6%, NEO 54.1%, FUR 64.7%, CIP 67.3%, CLO 73%, and FOS 81.3%. The susceptibility to RIF <400 and RIF <800μg/ml was significantly greater than with the other antibiotics (p<0.001). Resistance of enteropathogenic bacteria to various antibiotics used in gastrointestinal infections is high. Rifaximin was active against 99-100% of these enteropathogens at reachable concentrations in the intestine with the recommended dose. Copyright © 2015 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.
Full Text Available BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA infection is an important public health issue. The study aimed to determine the prevalence of ocular infections caused by MRSA and to identify the clinical characteristics and antibiotic susceptibility of ocular MRSA infections by comparing those of ocular methicillin-sensitive S. aureus (MSSA infections. METHODOLOGY/PRINCIPAL FINDINGS: The medical records of the patients (n = 519 with culture-proven S. aureus ocular infections seen between January 1, 1999 and December 31, 2008 in Chang Gung Memorial Hospital were retrospectively reviewed. Two hundred and seventy-four patients with MRSA and 245 with MSSA ocular infections were identified. The average rate of MRSA in S. aureus infections was 52.8% and the trend was stable over the ten years (P value for trend = 0.228. MRSA ocular infections were significantly more common among the patients with healthcare exposure (P = 0.024, but 66.1% (181/274 patients with MRSA ocular infections had no healthcare exposure. The most common clinical presentation for both MRSA and MSSA ocular infections was keratitis; MRSA and MSSA caused a similar disease spectrum except for lid infections. MRSA was significantly more resistant than MSSA to clindamycin, erythromycin and sulfamethoxazole/trimethoprim (all P<0.001. CONCLUSIONS/SIGNIFICANCE: We demonstrated a paralleled trend of ocular MRSA infection in a highly prevalent MRSA country by hospital-based survey. Except for lid disorder, MRSA shared similar spectrum of ocular pathology with MSSA. Since S. aureus is a common ocular pathogen, our results raise clinician's attention to the existence of highly prevalent MRSA.
Tan, Hsin-Yuan; Ma, David Hui-Kang; Lin, Ken-Kuo; Chang, Chee-Jen; Huang, Yhu-Chering
Background Methicillin-resistant Staphylococcus aureus (MRSA) infection is an important public health issue. The study aimed to determine the prevalence of ocular infections caused by MRSA and to identify the clinical characteristics and antibiotic susceptibility of ocular MRSA infections by comparing those of ocular methicillin-sensitive S. aureus (MSSA) infections. Methodology/Principal Findings The medical records of the patients (n = 519) with culture-proven S. aureus ocular infections seen between January 1, 1999 and December 31, 2008 in Chang Gung Memorial Hospital were retrospectively reviewed. Two hundred and seventy-four patients with MRSA and 245 with MSSA ocular infections were identified. The average rate of MRSA in S. aureus infections was 52.8% and the trend was stable over the ten years (P value for trend = 0.228). MRSA ocular infections were significantly more common among the patients with healthcare exposure (P = 0.024), but 66.1% (181/274) patients with MRSA ocular infections had no healthcare exposure. The most common clinical presentation for both MRSA and MSSA ocular infections was keratitis; MRSA and MSSA caused a similar disease spectrum except for lid infections. MRSA was significantly more resistant than MSSA to clindamycin, erythromycin and sulfamethoxazole/trimethoprim (all PMRSA infection in a highly prevalent MRSA country by hospital-based survey. Except for lid disorder, MRSA shared similar spectrum of ocular pathology with MSSA. Since S. aureus is a common ocular pathogen, our results raise clinician’s attention to the existence of highly prevalent MRSA. PMID:22880135
Azizah, Afina; Widyaningsih, Purnami; Retno Sari Saputro, Dewi
Ebola is a deadly infectious disease and has caused an epidemic on several countries in West Africa. Mathematical modeling to study the spread of Ebola disease has been developed, including through models susceptible infected removed (SIR) and susceptible exposed infected removed (SEIR). Furthermore, susceptible exposed infected isolated recovered (SEIIhR) model has been derived. The aims of this research are to derive SEIIhR model for Ebola disease, to determine the patterns of its spread, to determine the equilibrium point and stability of the equilibrium point using phase plane analysis, and also to apply the SEIIhR model on Ebola epidemic in Sierra Leone in 2014. The SEIIhR model is a differential equation system. Pattern of ebola disease spread with SEIIhR model is solution of the differential equation system. The equilibrium point of SEIIhR model is unique and it is a disease-free equilibrium point that stable. Application of the model is based on the data Ebola epidemic in Sierra Leone. The free-disease equilibrium point (Se; Ee; Ie; Ihe; Re )=(5743865, 0, 0, 0, 0) is stable.
Soler V, Tamara; Salamanca F, Lucía; Molina, Eliana
Aspirative pleuropulmonary infections are usually caused by anaerobic flora of the mouth, mainly Prevotella, Fusobacterium and Peptostreptococcus spp. Penicillin in high doses is the traditional treatment for this type of infections but the rising resistance developed in recent years has induced the empiric use of clindamycin, increasing treatment costs. To study antimicrobial susceptibility of anaerobic bacteria isolated from pleuropulmonary infections. Thirty two strains obtained from bronchoalveolar lavage and 15 strains isolated from pleural effusions between 2000 and 2002, were studied. The phenotype of strains was identified using the semiautomated API 20 A method and their susceptibility to penicillin (PNC), clindamycin (CM) and chloramphenicol (CAF) was tested using the E test methods. All the strains were susceptible to CAF, 95% to CM and 74.4% to PNC. The predominant genus was Prevotella, which also exhibited the higher resistance. As CM and CAF are active "in vitro", high rates of clinical response should be expected. In contrast, PNC is less effective, especially against pigmented Prevotella.
Congenital toxoplasmosis (CT) arises as a result of new acquisition of Toxoplasma infection by a susceptible woman during pregnancy. Early detection of CT through neonatal screening programmes could optimize management and improve infant outcome. This study sought to estimate the prevalence of Toxoplasma susceptibility in pregnant women. As detection of Toxoplasma antibodies in neonatal blood reflects maternal exposure history, maternal antibody seroprevalence was determined using anonymized residual blood from newborn screening cards. A total of 20,252 cards were tested in 1 year. 4,991 (24.6%) cards tested positive for Toxoplasma antibody. Results were stratified by county. Toxoplasma antibody seroprevalence rates of 25% indicated that Toxoplasma infection is common in Ireland and that up to 75% of women remain susceptible to primary infection during pregnancy. This study aimed to a) determine the seroprevalence of Toxoplasma antibody in pregnant women, and hence b) estimate the risk for acquisition of primary toxoplasmosis in pregnancy in order to support an application to fund a pilot newborn screening programme.
Temmam, Sarah; Davoust, Bernard; Berenger, Jean-Michel; Raoult, Didier; Desnues, Christelle
.... Several zoonotic viruses are transmitted to humans directly via contact with an animal or indirectly via exposure to the urine or feces of infected animals or the bite of a bloodsucking arthropod...
Andréa C. Fogaça
Full Text Available Rickettsia rickettsii is a tick-borne obligate intracellular bacterium that causes Rocky Mountain Spotted Fever (RMSF. In Brazil, two species of ticks in the genus Amblyomma, A. sculptum and A. aureolatum, are incriminated as vectors of this bacterium. Importantly, these two species present remarkable differences in susceptibility to R. rickettsii infection, where A. aureolatum is more susceptible than A. sculptum. In the current study, A. aureolatum and A. sculptum ticks were fed on suitable hosts previously inoculated with R. rickettsii, mimicking a natural infection. As control, ticks were fed on non-infected animals. Both midgut and salivary glands of all positively infected ticks were colonized by R. rickettsii. We did not observe ticks with infection restricted to midgut, suggesting that important factors for controlling rickettsial colonization were produced in this organ. In order to identify such factors, the total RNA extracted from the midgut (MG was submitted to next generation RNA sequencing (RNA-seq. The majority of the coding sequences (CDSs of A. sculptum differentially expressed by infection were upregulated, whereas most of modulated CDSs of A. aureolatum were downregulated. The functional categories that comprise upregulated CDSs of A. sculptum, for instance, metabolism, signal transduction, protein modification, extracellular matrix, and immunity also include CDSs of A. aureolatum that were downregulated by infection. This is the first study that reports the effects of an experimental infection with the highly virulent R. rickettsii on the gene expression of two natural tick vectors. The distinct transcriptional profiles of MG of A. sculptum and A. aureolatum upon infection stimulus strongly suggest that molecular factors in this organ are responsible for delineating the susceptibility to R. rickettsii. Functional studies to determine the role played by proteins encoded by differentially expressed CDSs in the acquisition of R
Dalrymple, S A; Lucian, L A; Slattery, R; McNeil, T; Aud, D M; Fuchino, S; Lee, F; Murray, R
We have produced interleukin-6 (IL-6)-deficient mice to examine, in vivo, the wide variety of biological activities attributed to this multifunctional cytokine. To investigate the role of IL-6 during infectious disease, IL-6-deficient mice were challenged with sublethal doses of Listeria monocytogenes, a facultative intracellular bacterium. While normal control animals were able to clear the infection, mutant animals exhibited a high mortality rate and showed uncontrolled replication of the b...
Bohn, Erwin; Schmitt, Edgar; Bielfeldt, Claudia; Noll, Annette; Schulte, Ralf; Autenrieth, Ingo B.
Endogenous interleukin-12 (IL-12) mediates protection against Yersinia enterocolitica in C57BL/6 mice by triggering gamma interferon (IFN-γ) production in NK and CD4+ T cells. Administration of exogenous IL-12 confers protection against yersiniae in Yersinia-susceptible BALB/c mice but exacerbates yersiniosis in resistant C57BL/6 mice. Therefore, we wanted to dissect the different mechanisms exerted by IL-12 during Yersinia infections by using different models of Yersinia-resistant and -susceptible mice, including resistant C57BL/6 mice, susceptible BALB/c mice, intermediate-susceptible wild-type 129/Sv mice, 129/Sv IFN-γ-receptor-deficient (IFN-γR−/−) mice and C57BL/6 tumor necrosis factor (TNF) receptor p55 chain-deficient (TNFR p55−/−) mice. IFN-γR−/− mice turned out to be highly susceptible to infection by Y. enterocolitica compared with IFN-γR+/+ mice. Administration of IL-12 was protective in IFN-γR+/+ mice but not in IFN-γR−/− mice, suggesting that IFN-γR-induced mechanisms are essential for IL-12-induced resistance against yersiniae. BALB/c mice could be rendered Yersinia resistant by administration of anti-CD4 antibodies or by administration of IL-12. In contrast, C57BL/6 mice could be rendered more resistant by administration of transforming growth factor β (TGF-β). Furthermore, IL-12-triggered toxic effects in C57BL/6 mice were abrogated by coadministration of TGF-β. While administration of IL-12 alone increased TNF-α levels, administration of TGF-β or TGF-β plus IL-12 decreased both TNF-α and IFN-γ levels in Yersinia-infected C57BL/6 mice. Moreover, IL-12 did not induce toxicity in Yersinia-infected TNFR p55−/− mice, suggesting that TNF-α accounts for IL-12-induced toxicity. Taken together, IL-12 may induce different effector mechanisms in BALB/c and C57BL/6 mice resulting either in protection or exacerbation. These results are important for understanding the critical balance of proinflammatory and regulatory
Wormser, Gary P; Schwartz, Ira
Despite resolution of the objective manifestations of Lyme disease after antibiotic treatment, a minority of patients have fatigue, musculoskeletal pain, and/or difficulties with concentration or short-term memory of uncertain etiology; these are called post-Lyme disease symptoms or, in more severe cases, post-Lyme disease syndrome or "chronic Lyme disease." Several recent studies in which Borrelia burgdorferi-infected animals were treated with antibiotic therapy have demonstrated the presence of PCR positivity for B. burgdorferi DNA in the absence of culture positivity. In mice that were treated with antibiotic therapy, residual spirochetes could be taken up by ticks during a blood meal and could be transmitted to SCID mice. These spirochetes are attenuated; their presence is not associated with either inflammation or disease. In this review the methodology and findings of these studies are critically analyzed, and the significance of the results with regard to human Lyme disease is evaluated, with special emphasis on whether these studies provide useful insights into post-Lyme disease syndrome. A serious methodological concern is the failure to consider the pharmacokinetic-pharmacodynamic properties of the antibiotic in choosing the dosage regimen used. We conclude that there is no scientific evidence to support the hypothesis that such spirochetes, should they exist in humans, are the cause of post-Lyme disease syndrome.
Ergunay, Koray; Tkachev, Sergey; Kozlova, Irina; Růžek, Daniel
Tick-borne encephalitis virus (TBEV) is the most important tick-transmitted arbovirus causing human disease in Europe and Asia. Over the past decades, the incidence of TBEV infection has significantly increased, with over 13,000 annual hospital referrals in endemic countries and cases emerging in previously unaffected regions. Specific detection of TBEV is required to diagnose suspected human cases or during surveillance of tick vectors and/or susceptible animal species. Widely used techniques for diagnosis comprise serological methods to detect viral antigens or antibodies and nucleic acid tests to detect viral RNA in target specimens. Moreover, virus isolation using susceptible cell lines or vertebrates, electron microscopy, or immunohistochemistry can also be employed on specific occasions. The purpose of this review is to compile and outline various approaches and techniques for detecting TBEV infection in ticks, wild animals, and humans. Specific sections for specimen collection and storage, nucleic acid testing, and serological assays cover various aspects of dynamics, performance characteristics, and utility in the diagnostic workup of suspected cases. Impact of immunoglobulin M testing and quantification, immunoglobulin G avidity, and real-time and quantitative polymerase chain reaction methods were overviewed with assay comparisons. Recent advances in serological assays to mitigate the impact of cross-reactions were further discussed along with the detailed interpretation of laboratory test results in human infections.
Hamad, Tarza; Hellmark, Bengt; Nilsdotter-Augustinsson, Åsa; Söderquist, Bo
In recent years, coagulase-negative staphylococci such as Staphylococcus epidermidis have gained importance as nosocomial pathogens, especially in immunocompromised patients and prosthetic joint infections (PJIs). These infections are often long lasting and difficult to treat due to the production of bacterial biofilm and the transformation of the bacteria into a stationary growth phase. Rifampicin is able to penetrate the biofilm, but to reduce the risk of development of rifampicin resistance it should be used in combination with an additional antibiotic. In this study we used Etest to investigate the antimicrobial susceptibility of 134 clinical isolates of S. epidermidis obtained from PJIs to six oral antibiotics: doxycycline, rifampicin, linezolid, fusidic acid, clindamycin, and ciprofloxacin. We also performed synergy testing on doxycycline in combination with each of the remaining antibiotics. Ninety-three (69%) of the 134 isolates were susceptible to doxycycline, 94/134 (70%) to rifampicin, 56/134 (42%) to clindamycin, 25/134 (19%) to ciprofloxacin, 81/134 (60%) to fusidic acid, and 100% to linezolid. Thirty-two (80%) of the 40 isolates not fully susceptible to rifampicin were susceptible to doxycycline. Doxycycline in combination with each of the other investigated antibiotics exerted an additive effect on nearly half of the isolates, with the exception of clindamycin, which displayed an even higher percentage of additive effect (69%). To conclude, as the majority of the S. epidermidis isolates were susceptible to doxycycline, this antimicrobial agent may provide a potential alternative for combination therapy together with rifampicin. © 2015 APMIS. Published by John Wiley & Sons Ltd.
Ataides, F S; Chaul, M H; El Essal, F E; Costa, C R; Souza, L K H; Fernandes, O F L; Silva, M R R
Onychomycosis is the nail infection caused by a wide spectrum of fungi species, including yeasts, dermatophytes and filamentous fungi non-dermatophytes (FFND). This fungal infection represents an important medical problem because it involves the patient's life quality. The aim was to isolate and identify the fungal agents of onychomycosis, and to determine the in vitro susceptibility to antifungal agents. During the period of March 2008 to March 2009, 114 patients clinically suspected of having onychomycosis were examined. Demographic data, mainly age and gender were obtained from each patient. The nail samples collected (136) were submitted to direct examination with potassium hydroxide 20% and grown on Sabouraud dextrose agar. The in vitro antifungal susceptibility testing was performed according to the method of broth microdilution, recommended by the Clinical Laboratory Standards Institute (CLSI). Onychomycosis was observed in 95 (83.3%) patients, including 16 men (16.8%) and 79 women (83.2%), with mean age of 48.1 years. Candida parapsilosis, Trichophyton rubrum and Fusarium spp were the fungi most frequently isolated. The most of the isolated yeasts showed susceptibility to antifungal agents studied. Among filamentous fungi, high MIC values to itraconazole were found for T. rubrum and T. mentagrophytes, while Fusarium spp showed decreased susceptibility to itraconazole and voriconazole. C. parapsilosis was the most common fungal species isolated from patients with onychomycosis. The different response obtained by in vitro susceptibility testing to drugs shows the importance of these methods to assist clinicians in choosing the best therapeutic option. © 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.
Full Text Available INTRODUCTION: Stenotrophomonas maltophilia is acquiring increasing importance as a nosocomial pathogen. METHODS: We retrospectively studied the characteristics and outcome of patients with any type of S. maltophilia infection at the University Hospital of Heraklion, Crete, Greece, between 1/2005-12/2010. S. maltophilia antimicrobial susceptibility was tested with the agar dilution method. Prognostic factors for all-cause in-hospital mortality were assessed with multivariate logistic regression. RESULTS: Sixty-eight patients (median age: 70.5 years; 64.7% males with S. maltophilia infection, not related to cystic fibrosis, were included. The 68 patients were hospitalized in medical (29.4%, surgical (26.5%, hematology/oncology departments (23.5%, or the intensive care units (ICU; 20.6%. The most frequent infection types were respiratory tract (54.4%, bloodstream (16.2%, skin/soft tissue (10.3%, and intra-abdominal (8.8% infection. The S. maltophilia-associated infection was polymicrobial in 33.8% of the cases. In vitro susceptibility was higher to colistin (91.2%, trimethoprim/sulfamethoxazole and netilmicin (85.3% each, and ciprofloxacin (82.4%. The empirical and the targeted treatment regimens were microbiologically appropriate for 47.3% and 63.6% of the 55 patients with data available, respectively. Most patients received targeted therapy with a combination of agents other than trimethoprim/sulfamethoxazole. The crude mortality and the mortality and the S. maltophilia infection-related mortality were 14.7% and 4.4%, respectively. ICU hospitalization was the only independent prognostic factor for mortality. CONCLUSION: S. maltophilia infection in a general hospital can be associated with a good prognosis, except for the patients hospitalized in the ICU. Combination reigmens with fluoroquinolones, colistin, or tigecycline could be alternative treatment options to trimethoprim/sulfamethoxazole.
Hald, Tine; Lo Fo Wong, Danilo M. A.; Aarestrup, Frank Møller
that of resistant isolates, which in turn was higher than that of susceptible isolates. This may be due to quinolone-resistant isolates having a higher ability to survive food processing and/or cause disease. This study showed domestic food to be the most important source of Salmonella infections in Denmark......Based on the Danish Salmonella surveillance in 2000-2001, we developed a mathematical model for quantifying the contribution of each major animal-food sources to human salmonellosis caused by antimicrobial resistant bacteria. Domestic food products accounted for 53.1% of all cases, mainly caused...
Danza, A; Ruiz-Irastorza, G
Infection is one of the leading causes of morbidity and mortality in systemic lupus erythematosus (SLE). Bacterial infections are most frequent, followed by viral and fungal infections. The impaired cellular and humoral immune functions seen in patients with SLE are predisposing conditions, whilst disease activity, prednisone doses over 7.5-10 mg/day, high doses of methylprednisolone or cyclophosphamide are well-recognised risk factors for infection. The first six months after rituximab treatment and the use of more than three courses are also associated with an increased susceptibility for infection. It has not been established whether belimumab, azathioprine and mycophenolate mofetil increase the risk of serious infections. Most vaccines are effective and safe in SLE patients, although vaccination should be avoided during periods of active disease. Live virus vaccines are contraindicated for immunosuppressed patients. Influenza and pneumococcal vaccines are universally recommended. Tuberculosis prophylaxis should be considered in selected cases. Therefore, it is advisable not to exceed doses of 5 mg/day of prednisone in chronic treatment. Methylprednisolone and cyclophosphamide should be used in low-dose regimens. Antimalarials have a well-known protective role against infection, in addition to other beneficial properties, thus, hydroxychloroquine is recommended for all SLE patients where no contraindication exists.
Tollenaere, C; Rahalison, L; Ranjalahy, M; Duplantier, J-M; Rahelinirina, S; Telfer, S; Brouat, C
In Madagascar, the black rat, Rattus rattus, is the main reservoir of plague (Yersinia pestis infection), a disease still responsible for hundreds of cases each year in this country. This study used experimental plague challenge to assess susceptibility in wild-caught rats to better understand how R. rattus can act as a plague reservoir. An important difference in plague resistance between rat populations from the plague focus (central highlands) and those from the plague-free zone (low altitude area) was confirmed to be a widespread phenomenon. In rats from the plague focus, we observed that sex influenced plague susceptibility, with males slightly more resistant than females. Other individual factors investigated (weight and habitat of sampling) did not affect plague resistance. When infected at high bacterial dose (more than 10⁵ bacteria injected), rats from the plague focus died mainly within 3-5 days and produced specific antibodies, whereas after low-dose infection (plague resistance level and the course of infection in the black rat would contribute to a better understanding of plague circulation in Madagascar.
Elks, Philip M; Brizee, Sabrina; van der Vaart, Michiel; Walmsley, Sarah R; van Eeden, Fredericus J; Renshaw, Stephen A; Meijer, Annemarie H
Tuberculosis is a current major world-health problem, exacerbated by the causative pathogen, Mycobacterium tuberculosis (Mtb), becoming increasingly resistant to conventional antibiotic treatment. Mtb is able to counteract the bactericidal mechanisms of leukocytes to survive intracellularly and develop a niche permissive for proliferation and dissemination. Understanding of the pathogenesis of mycobacterial infections such as tuberculosis (TB) remains limited, especially for early infection and for reactivation of latent infection. Signaling via hypoxia inducible factor α (HIF-α) transcription factors has previously been implicated in leukocyte activation and host defence. We have previously shown that hypoxic signaling via stabilization of Hif-1α prolongs the functionality of leukocytes in the innate immune response to injury. We sought to manipulate Hif-α signaling in a well-established Mycobacterium marinum (Mm) zebrafish model of TB to investigate effects on the host's ability to combat mycobacterial infection. Stabilization of host Hif-1α, both pharmacologically and genetically, at early stages of Mm infection was able to reduce the bacterial burden of infected larvae. Increasing Hif-1α signaling enhanced levels of reactive nitrogen species (RNS) in neutrophils prior to infection and was able to reduce larval mycobacterial burden. Conversely, decreasing Hif-2α signaling enhanced RNS levels and reduced bacterial burden, demonstrating that Hif-1α and Hif-2α have opposing effects on host susceptibility to mycobacterial infection. The antimicrobial effect of Hif-1α stabilization, and Hif-2α reduction, were demonstrated to be dependent on inducible nitric oxide synthase (iNOS) signaling at early stages of infection. Our findings indicate that induction of leukocyte iNOS by stabilizing Hif-1α, or reducing Hif-2α, aids the host during early stages of Mm infection. Stabilization of Hif-1α therefore represents a potential target for therapeutic
Philip M Elks
Full Text Available Tuberculosis is a current major world-health problem, exacerbated by the causative pathogen, Mycobacterium tuberculosis (Mtb, becoming increasingly resistant to conventional antibiotic treatment. Mtb is able to counteract the bactericidal mechanisms of leukocytes to survive intracellularly and develop a niche permissive for proliferation and dissemination. Understanding of the pathogenesis of mycobacterial infections such as tuberculosis (TB remains limited, especially for early infection and for reactivation of latent infection. Signaling via hypoxia inducible factor α (HIF-α transcription factors has previously been implicated in leukocyte activation and host defence. We have previously shown that hypoxic signaling via stabilization of Hif-1α prolongs the functionality of leukocytes in the innate immune response to injury. We sought to manipulate Hif-α signaling in a well-established Mycobacterium marinum (Mm zebrafish model of TB to investigate effects on the host's ability to combat mycobacterial infection. Stabilization of host Hif-1α, both pharmacologically and genetically, at early stages of Mm infection was able to reduce the bacterial burden of infected larvae. Increasing Hif-1α signaling enhanced levels of reactive nitrogen species (RNS in neutrophils prior to infection and was able to reduce larval mycobacterial burden. Conversely, decreasing Hif-2α signaling enhanced RNS levels and reduced bacterial burden, demonstrating that Hif-1α and Hif-2α have opposing effects on host susceptibility to mycobacterial infection. The antimicrobial effect of Hif-1α stabilization, and Hif-2α reduction, were demonstrated to be dependent on inducible nitric oxide synthase (iNOS signaling at early stages of infection. Our findings indicate that induction of leukocyte iNOS by stabilizing Hif-1α, or reducing Hif-2α, aids the host during early stages of Mm infection. Stabilization of Hif-1α therefore represents a potential target for
Elizabeth J Carlton
Full Text Available In light of multinational efforts to reduce helminthiasis, we evaluated whether there exist high-risk subpopulations for helminth infection. Such individuals are not only at risk of morbidity, but may be important parasite reservoirs and appropriate targets for disease control interventions.We followed two longitudinal cohorts in Sichuan, China to determine whether there exist persistent human reservoirs for the water-borne helminth, Schistosoma japonicum, in areas where treatment is ongoing. Participants were tested for S. japonicum infection at enrollment and two follow-up points. All infections were promptly treated with praziquantel. We estimated the ratio of the observed to expected proportion of the population with two consecutive infections at follow-up. The expected proportion was estimated using a prevalence-based model and, as highly exposed individuals may be most likely to be repeatedly infected, a second model that accounted for exposure using a data adaptive, machine learning algorithm. Using the prevalence-based model, there were 1.5 and 5.8 times more individuals with two consecutive infections than expected in cohorts 1 and 2, respectively (p<0.001 in both cohorts. When we accounted for exposure, the ratio was 1.3 (p = 0.013 and 2.1 (p<0.001 in cohorts 1 and 2, respectively.We found clustering of infections within a limited number of hosts that was not fully explained by host exposure. This suggests some hosts may be particularly susceptible to S. japonicum infection, or that uncured infections persist despite treatment. We propose an explanatory model that suggests that as cercarial exposure declines, so too does the size of the vulnerable subpopulation. In low-prevalence settings, interventions targeting individuals with a history of S. japonicum infection may efficiently advance disease control efforts.
Conclusion: We suggest drug susceptibility testing for more nontuberculous mycobateria, particularly M. avium complex isolated from infected birds and humans, as well as molecular basics of drug sensitivity in order to detect resistance genes of pathogenic M. avium subsp. avium.
Chauhan, Sanjeev Kumar
We propose a discrete-time dynamic network model describing the spread of susceptible-infective-recovered diseases in a population. We consider the case in which the nodes in the network change their links due to social mixing dynamics as well as in response to the disease. The model shows the behavior that, as we increase social mixing, disease spread is inhibited in certain cases, while in other cases it is enhanced. We also extend this dynamic network model to take into account the case of hidden infection. Here we find that, as expected, the disease spreads more readily if there is a time period after contracting the disease during which an individual is infective but is not known to have the disease.
Postnikova, Olga A; Hult, Maria; Shao, Jonathan; Skantar, Andrea; Nemchinov, Lev G
Nematodes are one of the major limiting factors in alfalfa production. Root-knot nematodes (RKN, Meloidogyne spp.) are widely distributed and economically important sedentary endoparasites of agricultural crops and they may inflict significant damage to alfalfa fields. As of today, no studies have been published on global gene expression profiling in alfalfa infected with RKN or any other plant parasitic nematode. Very little information is available about molecular mechanisms that contribute to pathogenesis and defense responses in alfalfa against these pests and specifically against RKN. In this work, we performed root transcriptome analysis of resistant (cv. Moapa 69) and susceptible (cv. Lahontan) alfalfa cultivars infected with RKN Meloidogyne incognita, widespread root-knot nematode species and a major pest worldwide. A total of 1,701,622,580 pair-end reads were generated on an Illumina Hi-Seq 2000 platform from the roots of both cultivars and assembled into 45,595 and 47,590 transcripts in cvs Moapa 69 and Lahontan, respectively. Bioinformatic analysis revealed a number of common and unique genes that were differentially expressed in susceptible and resistant lines as a result of nematode infection. Although the susceptible cultivar showed a more pronounced defense response to the infection, feeding sites were successfully established in its roots. Characteristically, basal gene expression levels under normal conditions differed between the two cultivars as well, which may confer advantage to one of the genotypes toward resistance to nematodes. Differentially expressed genes were subsequently assigned to known Gene Ontology categories to predict their functional roles and associated biological processes. Real-time PCR validated expression changes in genes arbitrarily selected for experimental confirmation. Candidate genes that contribute to protection against M. incognita in alfalfa were proposed and alfalfa-nematode interactions with respect to resistance
Dore, Maria Pina; Marras, Giuseppina; Rocchi, Chiara; Soro, Sara; Pes, Giovanni Mario
Subjects with glucose-6-phosphate dehydrogenase (G6PD) deficiency may be more susceptible to infections due to impaired leukocyte bactericidal activity. The disorder is common in the Mediterranean area. The aim of this study was to investigate whether G6PD deficiency may be a risk factor for acquiring H. pylori infection. We performed a retrospective study. Data from clinical records of 6565 patients (2278 men and 4287 women, median age 51, range 7‒94) who underwent upper endoscopy between 2002 and 2014 were collected. H. pylori status, assessed by histology plus rapid urease test or 13C-urea breath test, and G6PD status were also reported. A multiple logistic regression model was used to investigate the association between G6PD deficiency and H. pylori infection. Enzyme deficiency was detected in 12% (789/6565) of the entire cohort, and more specifically in 8.3% of men and in 14.0% of women. Overall, the proportion of patients positive for H. pylori was 50.6% and 51.5% among G6PD deficient and non-deficient patients (χ² = 0.271; p = 0.315). Moreover, among G6PD-deficient and normal patients the frequency of previous H. pylori infection was similar. After adjustment for age and gender the risk for acquiring H. pylori infection was similar in G6PD-deficient and normal patients. Only age was a strong statistically significant risk predictor. These results demonstrate for the first time that G6PD deficiency does not enhance patients' susceptibility to acquire H. pylori infection in Sardinia.
Dalgaard, Tina; Bøving, Mette K.; Handberg, Kurt
Resistance and susceptibility to Marek's disease (MD) are strongly influenced by the chicken major histocompatibility complex (MHC). In this study, splenic lymphocytes from MD-resistant and MD-susceptible chickens of three MHC genotypes (B21/B21, B19/B21, and B19/B19) were analyzed by flow...... genotypes were subjected to infection with MD virus (GA strain) and spleen samples from infected as well as MHC-matched negative controls were analyzed at 1, 4, and 8 wk post-infection (p.i.). It was observed that MDV induced an increase in MHC class I expression late in the infection. Thus, MHC class I...
Bereswill, S; Plickert, R; Fischer, A; Kühl, A A; Loddenkemper, C; Batra, A; Siegmund, B; Göbel, U B; Heimesaat, M M
Enterocolitis caused by Campylobacter jejuni-infections represents an important socioeconomic burden worldwide. Recent results from novel murine infection models reveal that the intestinal microbiota is essential for maintaining colonization resistance against C. jejuni. We extended these studies to investigate the role of nutrition and obesity in susceptibility to C. jejuni-infection. Gnotobiotic (GB) mice generated by antibiotic treatment, which were fed with a human cafeteria diet (CAF), as well as obese (ob/ob) mice with a conventional microbiota harbored higher Escherichia coli loads in their colon as compared to respective controls. Following oral infection, C. jejuni 43431 ATCC readily colonized the intestines of CAF and ob/ob mice, whereas GB mice fed with a standard chow (MUD) eradicated the pathogen within days. Furthermore, live C. jejuni translocated into mesenteric lymph nodes of CAF, but not MUD mice. Strikingly, stably infected animals developed enterocolitis as indicated by increased numbers of immune and apoptotic cells in the colon in situ. We conclude that a specific human diet and obesity render mice susceptible to C. jejuni infection. The corresponding murine models are excellently suited for the study of C. jejuni pathogenesis and will help to get further insights into interplays between C. jejuni, microbiota, diet, obesity and immunity.
Full Text Available Streptococcus suis type 2 (SS2 is an important swine pathogen and zoonosis agent. A/J mice are significantly more susceptible than C57BL/6 (B6 mice to SS2 infection, but the genetic basis is largely unknown. Here, alterations in gene expression in SS2 (strain HA9801-infected mice were identified using Illumina mouse BeadChips. Microarray analysis revealed 3,692 genes differentially expressed in peritoneal macrophages between A/J and B6 mice due to SS2 infection. Between SS2-infected A/J and control A/J mice, 2646 genes were differentially expressed (1469 upregulated; 1177 downregulated. Between SS2-infected B6 and control B6 mice, 1449 genes were differentially expressed (778 upregulated; 671 downregulated. These genes were analyzed for significant Gene Ontology (GO categories and signaling pathways using the Kyoto Encylopedia of Genes and Genomes (KEGG database to generate a signaling network. Upregulated genes in A/J and B6 mice were related to response to bacteria, immune response, positive regulation of B cell receptor signaling pathway, type I interferon biosynthesis, defense and inflammatory responses. Additionally, upregulated genes in SS2-infected B6 mice were involved in antigen processing and presentation of exogenous peptides, peptide antigen stabilization, lymphocyte differentiation regulation, positive regulation of monocyte differentiation, antigen receptor-mediated signaling pathway and positive regulation of phagocytosis. Downregulated genes in SS2-infected B6 mice played roles in glycolysis, carbohydrate metabolic process, amino acid metabolism, behavior and muscle regulation. Microarray results were verified by quantitative real-time PCR (qRT-PCR of 14 representative deregulated genes. Four genes differentially expressed between SS2-infected A/J and B6 mice, toll-like receptor 2 (Tlr2, tumor necrosis factor (Tnf, matrix metalloproteinase 9 (Mmp9 and pentraxin 3 (Ptx3, were previously implicated in the response to S. suis
Taha, Aza Bahadeen
Staphylococcus aureus is the main cause of diabetic foot infection with the patient's endogenous flora as the principal source. Nasal carriage of S. aureus has been identified as an important risk factor for the acquisition of diabetic foot infections. The study assessment the associations of S. aureus with methicillin resistant S. aureus were isolation from diabetic foot infection and nasal carriage of the same patients and their antibiotic susceptibility profile. Diagnosis of S. aureus and methicillin resistant S. aureus were carried out by using standard procedures. Antibiotic sensitivity profiles were determent by breakpoint dilution method. Out of 222 S. aureus isolation, 139 (62.61%) were isolated from the diabetic foot and 83 (37.39%) from the nasal carriage. Seventy one (30.87%) of the patients were S. aureus infection diabetic foot with nasal carriage. Among diabetic foot infection and nasal carriage patients, 40.85% of S. aureus were considered as methicillin resistant S. aureus. Rifampicin (96.40%) and Levofloxacin (91.44%) were active against S. aureus. Patients at strong risk for methicillin resistant S. aureus nasal carriage and subsequent diabetic foot infection with high resistance to antibiotics. Copyright © 2012 Elsevier Ltd. All rights reserved.
Wong, Tracie; Hildebrandt, Marie A; Thrasher, Seana M; Appleton, Judith A; Ahima, Rexford S; Wu, Gary D
Diet-induced obesity results from increased ingestion of energy-dense food and sedentary lifestyle in genetically susceptible individuals. An environmental factor that may have shaped our energy homeostasis throughout evolution is parasitic nematode infection. To test the hypothesis that a metabolically "thrifty phenotype" is advantageous during intestinal nematode infection, we compared the responses to Heligmosomoides polygyrus infection between 2 mouse strains: obesity-prone C57Bl/6J vs obesity-resistant SWR/J. Metabolic phenotyping was performed using indirect calorimetry, dual energy x-ray absorptiometry, and magnetic resonance imaging scanning. Gene expression was assessed by quantitative reverse-transcription polymerase chain reaction and immunohistochemistry. Body weight was maintained in both strains during nematode infection via different mechanisms. There was no apparent change in energy expenditure between the strains; however, SWR/J mice exhibited a marked hyperphagia (calorie intake 60% higher than C57Bl/6J) to maintain body weight. The importance of hyperphagia was confirmed by severe weight loss in a group of infected SWR/J mice whose food intake was restricted to that of naïve mice. Furthermore, SWR/J mice expelled nematodes more rapidly than C57Bl/6J mice, an effect related to a T helper cell 2 immune response. C57Bl/6J mice are more energy efficient during parasitic nematode infection, which may explain their ability to tolerate the infection. SWR/J mice, on the other hand, require an increase in food intake to maintain energy stores during nematode infection. In addition, a strong T helper cell 2-mediated immune response that facilitates a prompt clearance of nematode infection in SWR/J mice may have evolved to conserve energy in this strain.
Plasmodium infection in man is caused by the bite of an infected female Anopheles mosquito. This results in the disease, malaria. Malaria has serious debilitating effects on man. It adversely affectsman's health, strength and productivity. Here, a review of Plasmodium infection in man including the life cycle transmisson, ...
Full Text Available Bacteria of the genus Acinetobacter, especially species Acinetobacter baumanii, is one of the most important causes of infection in immunocompromised patients in hospital. The aim of this study was to determine susceptibility of Acinetobacter species isolated from swabs of inflamed wounds to antibiotics. The study was conducted in several departments of the Clinical Centre 'Kragujevac' through retrospective analysis of 220 Acinetobacter species isolates from surgical wounds in 2011. The isolates of Acinetobaster species were mostly sensitive to ampicillin-sulbactam, colistin and tigecycline in all hospital departments that were surveyed. Only minority of the isolated Acinetobacter species were susceptible to cotrimoxazole, amikacin, imipenem and/or meropenem. Antibiotics with the highest in vitro efficacy against Acinetobacter species were ampicillinsulbactam, colistin and tigecycline. Highly resistant Acinetobacter species were more frequently isolated from patients in Intensive Care Unit.
Yoo, Seung-Min; Jeon, Hyungtaek; Lee, Suhyuk; Lee, Myung-Shin
Pleural effusion lymphoma (PEL) is a rare B-cell lymphoma that has a very poor prognosis with a median survival time of around 6 months. PEL is caused by Kaposi's sarcoma-associated herpesvirus, and is often co-infected with the Epstein Barr virus. The complement system is fundamental in the innate immune system against pathogen invasion and tumor development. In the present study, we investigated the activation of the complement system in PEL cells using human serum complements. Interestingly, two widely used PEL cell lines, BCP-1 and BCBL-1, showed different susceptibility to the complement system, which may be due to CD46 expression on their cell membranes. Complement activation did not induce apoptosis but supported cell survival considerably. Our results demonstrated the susceptibility of PEL to the complement system and its underlying mechanisms, which would provide insight into understanding the pathogenesis of PEL.
Shu, Li-ping; Zuo, Li; Zhao, Xing; Chen, A-ying; Wei, Long-hua
To study the susceptibility of Aedes albopictus to dengue virus infection. Aedes albopictus from 15 collections in Guizhou province were challenged orally with dengue virus 1-4 types, respectively. The total RNA from mosquitos were extracted. The viral NS1 gene fragment was amplified with reverse transcriptase polymerase chain reaction (RT-PCR). Dengue virus in mosquitoes was isolated with C6/36 cells. Then the viral antigen was detected by indirect immunofluorescence assay (IFA). Antigen and nucleic acid of dengue virus from 15 geographic strains of Aedes albopictus orally infected with dengue viruses (DEN-1, DEN-2, DEN-3 and DEN-4) were detected by IFA, RT-PCR and the virus was isolated with C6/36 cells, respectively. The rates of Aedes albopictus orally infected with DEN-1, DEN-2, DEN-3 and DEN-4 were 12/15, 12/15, 8/15 and 13/15, respectively. Different geographic strains of Aedes albopitus in Guizhou were susceptible to dengue viruses.
Ettensohn, David B; Frampton, Mark W; Nichols, Joan E; Roberts, Norbert J
The current studies were undertaken to determine the susceptibility of human alveolar macrophages (AMs) to influenza A virus (IAV) infection in comparison with autologous peripheral blood-derived monocytes-macrophages (PBMs). AMs and PBMs were exposed to IAV in vitro and examined for their ability to bind and internalize IAV, and synthesize viral proteins and RNA. PBMs but not AMs demonstrated binding and internalization of the virus, synthesizing viral proteins and RNA. Exposure of AMs in the presence of a sialidase inhibitor or anti-IAV antibody resulted in viral protein synthesis by the cells. Exposure of AMs to fluorescein isothiocyanate-labeled IAV in the presence of anti-fluorescein isothiocyanate antibody also resulted in viral protein synthesis. Thus, human AMs are apparently not susceptible to direct infection by a human IAV but are likely to be infected indirectly in the setting of exposure in the presence of antibody that binds the challenging strain of IAV. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail email@example.com.
Hijazi, Karolin; Mukhopadhya, Indrani; Abbott, Felicity; Milne, Kathleen; Al-Jabri, Zaaima J; Oggioni, Marco R; Gould, Ian M
The emergence of Staphylococcus isolates with reduced susceptibility to chlorhexidine is being increasingly reported. We present an update to a previous report showing the continuing efficacy of chlorhexidine-based infection control measures against Staphylococcus aureus over 6 years. In this study, qacA/B genes were screened in Staphylococcus isolates collected over another 6 years in the same intensive care unit in Scotland where chlorhexidine baths form an essential component of long-term control of nosocomial infections. Consistent with our previous study, we report minimal presence of qacA/B in S. aureus strains from screening samples and bacteraemia patients but the new finding of a high proportion of qacA/B carriage in Staphylococcus epidermidis associated with reduced susceptibility to chlorhexidine. S. epidermidis isolates positive for qacA/B were clonally diverse, although 65% of isolates belonged to the multidrug-resistant (MDR) clone ST2. These findings raise concerns in relation to the selection of MDR strains by chlorhexidine and are important in the context of recent evidence emphasising the benefits of targeting bloodstream infections associated with coagulase-negative staphylococci. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.
A pattern of sedentary lifestyle beginning in childhood is associated with obesity and related disorders such as type 2 diabetes. Obesity is associated with increased susceptibility to air pollutants and initiating regular exercise early in life should impact positively on respir...
Aarestrup, Frank Møller; Tvede, Michael
A total of 65 toxigenic Clostridium difficile strains isolated from patients with antibiotic-associated diarrhea were tested for susceptibility to avilamycin, flavomycin, monensin, and salinomycin. Except for flavomycin the substances showed in vitro efficacy comparable to reports of the currently...
Plachý, Jiří; Reinišová, Markéta; Kučerová, Dana; Šenigl, Filip; Stepanets, Volodymyr; Hron, Tomáš; Trejbalová, Kateřina; Elleder, Daniel; Hejnar, Jiří
The J subgroup of avian leukosis virus (ALV-J) infects domestic chickens, jungle fowl, and turkeys. This virus enters the host cell through a receptor encoded by the tvj locus and identified as Na+/H+ exchanger 1. The resistance to avian leukosis virus subgroup J in a great majority of galliform species has been explained by deletions or substitutions of the critical tryptophan 38 in the first extracellular loop of Na+/H+ exchanger 1. Because there are concerns of transspecies virus transmission, we studied natural polymorphisms and susceptibility/resistance in wild galliforms and found the presence of tryptophan 38 in four species of New World quails. The embryo fibroblasts of New World quails are susceptible to infection with avian leukosis virus subgroup J, and the cloned Na+/H+ exchanger 1 confers susceptibility on the otherwise resistant host. New World quails are also susceptible to new avian leukosis virus subgroup J variants but resistant to subgroups A and B and weakly susceptible to subgroups C and D of avian sarcoma/leukosis virus due to obvious defects of the respective receptors. Our results suggest that the avian leukosis virus subgroup J could be transmitted to New World quails and establish a natural reservoir of circulating virus with a potential for further evolution. Since its spread in broiler chickens in China and Southeast Asia in 2000, ALV-J remains a major enzootic challenge for the poultry industry. Although the virus diversifies rapidly in the poultry, its spillover and circulation in wild bird species has been prevented by the resistance of most species to ALV-J. It is, nevertheless, important to understand the evolution of the virus and its potential host range in wild birds. Because resistance to avian retroviruses is due particularly to receptor incompatibility, we studied Na+/H+ exchanger 1, the receptor for ALV-J. In New World quails, we found a receptor compatible with virus entry, and we confirmed the susceptibilities of four New
Saaiq, Muhammad; Ahmad, Shehzad; Zaib, Muhammad Salman
BACKGROND Burn wound infections carry considerable mortality and morbidity amongst burn injury victims who have been successfully rescued through the initial resuscitation. This study assessed the prevalent microrganisms causing burn wound infections among hospitalized patients; their susceptibility pattern to commonly used antibiotics; and the frequency of infections with respect to the duration of the burn wounds. METHODS This study was carried out at Burn Care Centre, Pakistan Institute of Medical Sciences (PIMS), Islamabad, Pakistan over a period of two years (i.e. from June 2010 to May 2012). The study included all wound-culture-positive patients of either gender and all ages, who had sustained deep burns and underwent definitive management with wound excisions and skin auto-grafting. Patients with negative cultures of the wounds were excluded. Tissue specimens for culture and sensitivity were collected from burn wounds using standard collection techniques and analyzed at microbiological laboratory. RESULTS Out of a total of 95 positive microbial growths, 36 were Pseudomonas aeruginosa (35.29%) as the most frequent isolate found, followed by 21 Klebsiella pneumoniae (20.58%), 19 Staphylococcus aureaus (18.62%), 10 Proteus (9.80%), 7 E. coli (6.86%), 7 Acinetobacter (6.86%), and 4 Candida (3.92%). A variable antibiotic susceptibility pattern was observed among the grown microbes. Positive cultures were significantly more frequent among patients with over two weeks duration of burn wounds. CONCLUSION P. aeruginosa, K. pneumoniae and S. aureus constituted the most common bacterial microbes of burn wounds in our in-patients cases. Positive cultures were more frequent among patients with over two weeks duration of burn wounds. Early excision and skin grafting of deep burns and adherence to infection control measures can help to effectively reduce the burden of these infections. PMID:25606471
Four species of mosquitoes which represent the Tonga group of the Aedes scutellaris complex (Ae. cooki, Ae. kesseli, Ae. tongae tabu and an undescribed Aedes sp. NUAOFO'OU) were tested for susceptibility to infection with Brugia malayi and B. pahangi. All tested strains were genetically fully (100%) susceptible to infection with both parasitic helminths. Higher survival of females harboring low quantities of infective larvae (1-9 L3/male) indicates a weak adaptation of the host to the parasite. Further analysis showed that in frequency distribution of infective larvae of B. malayi and B. pahangi, the most frequent category was 1-5 infective larvae per mosquito female. Distribution of te infective larvae into various parts of the mosquito body is a dynamic process. After development of L3 larvae in the thoracic muscles is completed, infective larvae migrate predominantly to the abdomen. From day 10 to 18 after an infective blood meal, L3 larvae migrate back to the thorax and head proboscis area. Low density of microfilariae in gerbils (5 mf/20 microliters) is sufficient for good infection in any of the tested mosquito species and strains. If a laboratory model with high susceptibility of mosquitoes to Brugia filarial worms is required, the autogenous group of mosquitoes of Tonga will serve as an excellent laboratory model. High susceptibility of the autogenous mosquito species to B. malayi and B. pahangi and absence of Brugian filariasis in the Polynesian region of the South Pacific is discussed.
Dibua, Uju M.E.; Onyemerela, Ifeoma S.; Nweze, Emeka I.
Objective: This study was designed to determine the frequency and causative agent(s) of urinary tract infections (UTIs) in individuals with symptoms of urinary tract infections in Enugu State of Southeast Nigeria, and to determine the antibiotic susceptibility pattern of microbial agents isolated from urine culture. Methods: The study involved 211 individuals (149 females and 62 males) clinically suspected for UTI. Urine samples were collected by the mid-stream ‘clean catch’ method and tested using standard procedures. Antibiotic susceptibility of the isolated pathogens was tested using the Kirby-Bauer technique according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Microscopy of centrifuged urine samples showed 16 patients had pyuria while 54 had pus cells. Calcium oxalate crystals were found in 14 samples. Urinalysis performed with urine samples showed 17 had protein; seven were nitrite positive and three had moderate to high glucose concentration. Fifty-four urine samples (36.2%) from females and 12 (19.4%) from males showed significant growth upon culture. Gram stain and biochemical tests identified nine different organisms with Escherichia coli as the most common isolated species. Forty three randomly selected strains were further tested for their susceptibility against a panel of antibiotics. Thirty isolates (81.08%) were resistant to four or more antibiotics with the highest resistance shown by E. coli (76.67%). All the Gram- negative isolates were resistant to Ampicilox, Cefuroxime and Amoxicillin. Conclusion: Urinary tract infections were found more in females in the area under study. As found in other studies, E. coli was the most predominant isolate, although other organisms seem to be on the increase. PMID:24553609
Uju M.E. Dibua
Full Text Available Objective: This study was designed to determine the frequency and causative agent(s of urinary tract infections (UTIs in individuals with symptoms of urinary tract infections in Enugu State of Southeast Nigeria, and to determine the antibiotic susceptibility pattern of microbial agents isolated from urine culture. Methods: The study involved 211 individuals (149 females and 62 males clinically suspected for UTI. Urine samples were collected by the mid-stream ‘clean catch' method and tested using standard procedures. Antibiotic susceptibility of the isolated pathogens was tested using the Kirby-Bauer technique according to the Clinical and Laboratory Standards Institute (CLSI guidelines. Results: Microscopy of centrifuged urine samples showed 16 patients had pyuria while 54 had pus cells. Calcium oxalate crystals were found in 14 samples. Urinalysis performed with urine samples showed 17 had protein; seven were nitrite positive and three had moderate to high glucose concentration. Fifty-four urine samples (36.2% from females and 12 (19.4% from males showed significant growth upon culture. Gram stain and biochemical tests identified nine different organisms with Escherichia coli as the most common isolated species. Forty three randomly selected strains were further tested for their susceptibility against a panel of antibiotics. Thirty isolates (81.08% were resistant to four or more antibiotics with the highest resistance shown by E. coli (76.67%. All the Gram- negative isolates were resistant to Ampicilox, Cefuroxime and Amoxicillin. Conclusion: Urinary tract infections were found more in females in the area under study. As found in other studies, E. coli was the most predominant isolate, although other organisms seem to be on the increase.
Earl, Patricia L; Americo, Jeffrey L; Moss, Bernard
The castaneous (CAST) mouse, a wild-derived inbred strain, is highly susceptible to orthopoxvirus infection by intranasal and systemic routes. The 50% lethal intraperitoneal dose of vaccinia virus (VACV) was 3 PFU for CAST mice, whereas BALB/c mice survived 106 PFU. At all times and in all organs analyzed, virus titers were higher in CAST than in BALB/c mice. In individual CAST mice, luciferase-expressing VACV was seen to replicate rapidly leading to death, whereas virus levels increased for a few days and then declined in BALB/c mice. Increases in gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) were delayed and low in CAST mice compared to BALB/c mice following VACV infection or poly(I-C) inoculation, consistent with differences in innate immune responses. In addition, naive CAST mice had considerably lower numbers of NK and T cells than BALB/c mice. The percentage of IFN-γ-producing CD4+ and CD8+ T cells increased following infection of CAST mice only after considerable virus spread, and the absolute cell numbers remained low. Administration of exogenous IFN-γ or -α to CAST mice before or during the first days of infection suppressed virus replication and prolonged survival, allowing the mice to make adaptive CD4+ and CD8+ T cell responses that were necessary to clear the virus after cessation of interferon treatment. Thus, insufficient innate cytokine and cellular immune responses contribute to the unique susceptibility of CAST mice to VACV, whereas the adaptive immune response can be protective only if virus replication is suppressed during the first several days of infection.IMPORTANCE Most inbred mouse strains are relatively resistant to orthopoxviruses. The castaneous (CAST) mouse is a notable exception, exhibiting extreme vulnerability to monkeypox virus, cowpox virus, and vaccinia virus and thus providing a unique model for studying pathogenicity, immunity, vaccines, and antiviral drugs. To fully utilize the CAST mouse for such
Guardabassi, Luca; Hedberg, Sandra; Jessen, Lisbeth Rem; Damborg, Peter
Urinary tract infection (UTI) is a common reason for antimicrobial prescription in dogs and cats. The objective of this study was to optimize and evaluate a culture-based point-of-care test for detection, identification and antimicrobial susceptibility testing of bacterial uro-pathogens in veterinary practice. Seventy-two urine samples from dogs and cats with suspected UTI presenting to seven veterinary facilities were used by clinical staff and an investigator to estimate sensitivity and specificity of Flexicult Vet A compared to laboratory reference standards for culture and susceptibility testing. Subsequently, the test was modified by inclusion of an oxacillin-containing compartment for detection of methicillin-resistant staphylococci. The performance of the modified product (Flexicult Vet B) for susceptibility testing was evaluated in vitro using a collection of 110 clinical isolates. Bacteriuria was reported by the laboratory in 25 (35 %) samples from the field study. The sensitivity and specificity of Flexicult Vet A for detection of bacteriuria were 83 and 100 %, respectively. Bacterial species were correctly identified in 53 and 100 % of the positive samples by clinical staff and the investigator, respectively. The susceptibility results were interpreted correctly by clinical staff for 70 % of the 94 drug-strain combinations. Higher percentages of correct interpretation were observed when the results were interpreted by the investigator in both the field (76 %) and the in vitro study (94 %). The most frequent errors were false resistance to β-lactams (ampicillin, amoxicillin-clavulanate and cephalotin) in Escherichia coli for Flexicult Vet A, and false amoxicillin-clavulanate resistance in E. coli and false ampicillin susceptibility in Staphylococcus pseudintermedius for Flexicult Vet B. The latter error can be prevented by categorizing staphylococcal strains growing in the oxacillin compartment as resistant to all β-lactams. Despite the
Full Text Available Abstract Background In order to attain a better understanding of the interactions between opportunist fungi and their hosts, we investigated the cytokine profile associated with the inflammatory response to Candida albicans infection in mice with solid Ehrlich tumors of different degrees. Methods Groups of eight animals were inoculated intraperitoneally with 5 × 106 C. albicans 7, 14 or 21 days after tumor implantation. After 24 or 72 hours, the animals were euthanized and intraperitoneal lavage fluid was collected. Peritoneal macrophages were cultivated and the levels of IFN-γ, TNF-α, IL-12, IL-10 and IL-4 released into the supernatants were measured by ELISA. Kidney, liver and spleen samples were evaluated for fungal dissemination. Tumor-free animals and animals that had only been subjected to C. albicans infection were used as control groups. Results Our results demonstrated that the mice produced more IFN-γ and TNF-α and less IL-10, and also exhibited fungal clearance, at the beginning of tumor evolution. With the tumor progression, this picture changed: IL-10 production increased and IFN-γ and TNF-α release decreased; furthermore, there was extensive fungal dissemination. Conclusion Our results indicate that solid tumors can affect the production of macrophage cytokines and, in consequence, affect host resistance to opportunistic infections.
Full Text Available Aims: We aimed to compare Salmonella isolates from different sources using molecular and phenotypic methods, targeting better possibility of understanding the epidemiology of this organism in the Greek context with emphasis in municipal wastewater. Materials and Methods: In this study, we used pulsed field gel electrophoresis (PFGE in combination with antimicrobial susceptibility testing to analyze a total of 88 Salmonella Enterica isolates from municipal sewage (n=25, humans (n=36, animals (n=24, and foods (n=3 in Greece. Results: The higher resistance rates were found to the following antimicrobials: streptomycin (59.1%, tetracycline (47.7%, nalidixic acid (46.6%, ampicillin (37.5%, and oxolinic acid (35.2%. Resistance to ciprofloxacin was not observed; 22 isolates (25% were sensitive to all 9 antimicrobials, 36%, 25% and 12% of human, animal and wastewater origin, respectively, showing a significant difference. Salmonella ser. Hadar was the serovar with the highest resistance rates followed by Salmonella ser. Anatum and Salmonella ser. Typhimurium; Salmonella ser. Infantis strains were almost pansusceptible. Cluster analysis did not reveal close genetic relationship between human animal food and wastewater strains belonging to the same serovars. In most of the cases, distinct clusters were observed between human and non-human isolates indicating diversity and no epidemiological connection. Conclusion: This study indicates that municipal wastewater would be of interest to further monitor the community’s prevalence of subclinical or non-reported S. Enterica infections.
Full Text Available Abstract Bluetongue virus serotype 8 (BTV-8, which caused an epidemic in ruminants in central Western Europe in 2006 and 2007, seems to differ from other bluetongue serotypes in that it can spread transplacentally and has been associated with an increased incidence of abortion and other reproductive problems. For these reasons, and also because BTV-8 is threatening to spread to other parts of the world, there is a need for more information on the consequences of infection during pregnancy. The aim of the present study was to investigate whether hatched (i.e. zona pellucida-free in vitro produced bovine blastocysts at 8-9 days post insemination are susceptible to BTV-8 and whether such infection induces cell death as indicated by apoptosis. Exposure of hatched in vitro produced bovine blastocysts for 1 h to a medium containing 103.8 or 104.9 TCID50 of the virus resulted in active viral replication in between 25 and 100% of the cells at 72 h post exposure. The infected blastocysts also showed growth arrest as evidenced by lower total cell numbers and a significant level of cellular apoptosis. We conclude from this in vitro study that some of the reproductive problems that are reported when cattle herds are infected with BTV-8 may be attributed to direct infection of blastocysts and other early-stage embryos in utero.
Tu, Li-Tzu; Liu, Fu-Ping; Huang, Yhu-Chering; Huang, Chung-Guei; Yang, Shuan; Tsao, Kuo-Chien; Lai, Ming-Wei; Chen, Chih-Jung
A comprehensive evaluation of associations between the susceptibility to norovirus infections and histo-blood group antigens is not available in the Taiwanese population, in which the nonsecretor phenotype is absent. A 1:1 matched case-control study was conducted in northern Taiwan from February 2013 to December 2014 when an epidemic of norovirus infection occurred. Cases were children norovirus infections. Controls were healthy children matched to the cases by age and gender. The norovirus genotype was determined by polymerase chain reaction sequencing of the VP1 gene. The secretor status, Lewis antigen and ABO type were determined by characterization of genetic polymorphisms in the FUT2, FUT3 and ABO genes, respectively. A total of 147 case-control pairs were included. GII.4 Sydney strain was the major genotype and identified in 78.3% of the cases. The weak-secretor and Lewis-positive genotypes were less commonly identified in cases than in controls (5.4% vs. 23.1% and 79.6% vs. 89.8%, respectively). Multivariate analysis revealed that the secretor and Lewis-negative genotypes were both independent factors associated with increased risk of norovirus infections [matched odds ratio: 6.766, 95% confidence interval (CI): 2.649-17.285, P norovirus infections (P > 0.05). The weak-secretor genotype and the Lewis antigen-positive genotype were both protective factors against severe norovirus gastroenteritis during the GII.4 Sydney strain epidemic in Taiwan.
Jorge Pinto Ferreira
Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is a significant pathogen in both human and veterinary medicine. The importance of companion animals as reservoirs of human infections is currently unknown. The companion animals of 49 MRSA-infected outpatients (cases were screened for MRSA carriage, and their bacterial isolates were compared with those of the infected patients using Pulsed-Field Gel Electrophoresis (PFGE. Rates of MRSA among the companion animals of MRSA-infected patients were compared to rates of MRSA among companion animals of pet guardians attending a "veterinary wellness clinic" (controls. MRSA was isolated from at least one companion animal in 4/49 (8.2% households of MRSA-infected outpatients vs. none of the pets of the 50 uninfected human controls. Using PFGE, patient-pets MRSA isolates were identical for three pairs and discordant for one pair (suggested MRSA inter-specie transmission p-value = 0.1175. These results suggest that companion animals of MRSA-infected patients can be culture-positive for MRSA, representing a potential source of infection or re-infection for humans. Further studies are required to better understand the epidemiology of MRSA human-animal inter-specie transmission.
Full Text Available Non-tuberculous mycobacteria (NTM are environmental microbes that cause a variety of diseases both in immunocompromised and immunocompetent patients. Epidemiologic data indicate that there has been a global rise in the incidence of NTM infections. It has also been noted that NTM infections have a predilection to occur in postmenopausal women. In a recent study, it was demonstrated that in patients with non-CF bronchiectasis the probability of NTM isolation was significantly higher in elderly female patients and in those with a low body mass index. However, the mechanisms of causality of these gender differences and morpho-phenotypes remain enigmatic. The present study reviews the data and plausible mechanisms which might provide clues to this gender susceptibility and morpho-phenotypes of patients with bronchiectasis and NTM.
Gerla, D.J.; Gsell, A.S.; Kooi, B.W.; Ibelings, B.W.; Donk, van E.; Mooij, W.M.
1. Despite the strong impact parasites can have, only few models of phytoplankton ecology or aquatic food webs have specifically included parasitism. 2. Here, we provide a susceptible-infected model for a diatom-chytrid hostparasite system that explicitly includes nutrients, infected and uninfected
Gerla, D.J.; Gsell, A.S.; Kooi, B.W.; Ibelings, B.W.; Van Donk, E.; Mooij, W.M.
1. Despite the strong impact parasites can have, only few models of phytoplankton ecology or aquatic food webs have specifically included parasitism. 2. Here, we provide a susceptible-infected model for a diatom-chytrid host–parasite system that explicitly includes nutrients, infected and uninfected
Storm Jeremy C
Full Text Available Abstract Background Daptomycin non-susceptible enterococci (DNSE are emerging as an important cause of healthcare-associated infection, however little is known about the epidemiology of DNSE. At the University of Iowa Hospitals and Clinics (UIHC an increase in the frequency of patients infected and/or colonized with DNSE has occurred. The goals of this study were to evaluate potential factors associated with the development of DNSE colonization and/or infection and to compare the characteristics of patients with prior daptomycin exposure to those without prior daptomycin exposure. Methods The study is a retrospective case-series involving all patients with DNSE infection and/or colonization at UIHC, a 734-bed academic referral center, from June 1, 2005 to June 1, 2011. Results The majority of patients with DNSE colonization and/or infection had prior daptomycin exposure (15 of 25; 60%, a concomitant gastrointestinal process (19 of 25; 76%, or were immunosuppressed (21 of 25; 84%. DNSE infection was confirmed in 17 of 25 (68% patients, including 9 patients with bacteremia. Twelve of 17 (71% patients with DNSE infection had prior daptomycin exposure, including 7 of 9 (78% patients with bacteremia. Compared to patients without prior daptomycin exposure, patients with prior daptomycin exposure were less likely to harbor E. faecalis (0% vs. 33%; p = 0.019. A high proportion of patients (10 of 25; 40% died during their hospitalizations. Most enterococcal isolates were E. faecium (86%, and were vancomycin-resistant (72%. Molecular typing revealed a diverse population of DNSE. Conclusions Prior daptomycin exposure, immunosuppression, and/or a concomitant gastrointestinal process, may be associated with the development of DNSE. PFGE revealed a diverse population of DNSE, which along with both increasing numbers of DNSE detected yearly and increasing annual rates of daptomycin usage, suggests the emergence of DNSE under antimicrobial pressure.
Siler, Ulrich; Romao, Susana; Tejera, Emilio; Pastukhov, Oleksandr; Kuzmenko, Elena; Valencia, Rocio G; Meda Spaccamela, Virginia; Belohradsky, Bernd H; Speer, Oliver; Schmugge, Markus; Kohne, Elisabeth; Hoenig, Manfred; Freihorst, Joachim; Schulz, Ansgar S; Reichenbach, Janine
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymatic disorder of red blood cells in human subjects, causing hemolytic anemia linked to impaired nicotinamide adenine dinucleotide phosphate (NADPH) production and imbalanced redox homeostasis in erythrocytes. Because G6PD is expressed by a variety of hematologic and nonhematologic cells, a broader clinical phenotype could be postulated in G6PD-deficient patients. We describe 3 brothers with severe G6PD deficiency and susceptibility to bacterial infection. We sought to study the molecular pathophysiology leading to susceptibility to infection in 3 siblings with severe G6PD deficiency. Blood samples of 3 patients with severe G6PD deficiency were analyzed for G6PD enzyme activity, cellular oxidized nicotinamide adenine dinucleotide phosphate/NADPH levels, phagocytic reactive oxygen species production, neutrophil extracellular trap (NET) formation, and neutrophil elastase translocation. In these 3 brothers strongly reduced NADPH oxidase function was found in granulocytes, leading to impaired NET formation. Defective NET formation has thus far been only observed in patients with the NADPH oxidase deficiency chronic granulomatous disease, who require antibiotic and antimycotic prophylaxis to prevent life-threatening bacterial and fungal infections. Because severe G6PD deficiency can be a phenocopy of chronic granulomatous disease with regard to the cellular and clinical phenotype, careful evaluation of neutrophil function seems mandatory in these patients to decide on appropriate anti-infective preventive measures. Determining the level of G6PD enzyme activity should be followed by analysis of reactive oxygen species production and NET formation to decide on required antibiotic and antimycotic prophylaxis. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Lim, Stephanie M; Brault, Aaron C; van Amerongen, Geert; Bosco-Lauth, Angela M; Romo, Hannah; Sewbalaksing, Varsha D; Bowen, Richard A; Osterhaus, Albert D M E; Koraka, Penelope; Martina, Byron E E
West Nile virus (WNV) outbreaks in North America have been characterized by substantial die-offs of American crows (Corvus brachyrhynchos). In contrast, a low incidence of bird deaths has been observed during WNV epidemic activity in Europe. To examine the susceptibility of the western European counterpart of American crows, we inoculated carrion crows (Corvus corone) with WNV strains isolated in Greece (Gr-10), Italy (FIN and Ita09), and Hungary (578/10) and with the highly virulent North American genotype strain (NY99). We also inoculated American crows with a selection of these strains to examine the strains' virulence in a highly susceptible bird species. Infection with all strains, except WNV FIN, resulted in high rates of death and high-level viremia in both bird species and virus dissemination to several organs. These results suggest that carrion crows are highly susceptible to WNV and may potentially be useful as part of dead bird surveillance for early warning of WNV activity in Europe.
Haubruck, Patrick; Schmidmaier, Gerhard
Despite modern treatment options, implant-associated infections (IAI) remain a severe and challenging complication in the treatment of trauma patients. Almost 30 years after the introduction of implants made of titanium alloy into the treatment of trauma patients, there is still no uniform consensus regarding the clinical benefit of titanium alloy in the context of patients with IAI. We sought to determine if implants made of titanium alloy have been proven to be less susceptible regarding IAI in contrast to implants made of stainless steel. A review of the current literature on IAI in association with the utilized implant material was conducted. Relevant articles from the years 1995 to 2016 were searched in the PubMed database. A total of 183 articles were identified and all abstracts were reviewed for relevance. A total of 14 articles met the inclusion criteria and were stratified according to the level of evidence and furthermore evaluated regarding the influence of the implant material on IAI. Considerable debate remains concerning the influence of the implant material on the susceptibility to IAI; however, the available literature shows that despite slight tendencies, there is no proof of titanium alloy being favorable in the susceptibility to IAI. Furthermore, the literature shows that the design of plates for osteosynthesis might influence IAI. In particular, plates that cause less soft tissue damage and preserve perfusion of the periosteum proved to be beneficial regarding IAI.
Wang, Y Q; Zhang, X F; Li, N; Liu, X
Bacterial spot of tomato (Solanum lycopersicum L.) caused by several Xanthomonas species is one of the most destructive diseases. Genes regulating the hypersensitive resistance and field resistance to X. perforans race T3 have been intensively investigated over the last decade. However, a comparative analysis of cellular responses to the pathogen in susceptible and resistant hosts has not been completed, which prevents the detailed understanding of the interactions between the pathogen and tomato plants. In this study, the characteristics of lesions, stomata, and pathogen colonization in hypersensitive response (HR) PI 128216, field-resistant PI 114490, and susceptible OH 88119 tomato plants after inoculation with green fluorescent protein-labeled X. perforans race T3 bacteria were investigated. Significant differences in developmental processes and the micromorphology of spot lesions among three tomato lines were observed. Our results suggested that the faster lesion development in OH 88119 plants compared with that of the other two lines was associated with a greater increase in the stomatal apertures over a longer period following bacterial inoculation. The depth of bacterial colonization and pathogen density inside infected leaves in OH 88119 were also significantly different from that of resistant tomato plants. Determination of the ultrastructural responses to X. perforans among three tomato lines revealed that cell wall defense response was the main difference between resistant and susceptible tomato lines. These results may provide fundamental information for understanding the cellular and molecular mechanisms regulating tomato responses to X. perforans race T3. Copyright © 2016 Elsevier GmbH. All rights reserved.
Treviño, Mercedes; Losada, Isabel; Fernández-Pérez, Begoña; Coira, Amparo; Peña-Rodríguez, Maria F; Hervada, Xurxo
Escherichia coli is the microorganism responsible for most of the community-acquired urinary tract infections (UTI). Our purpose was to determine the susceptibility of E. coli associated with UTI in Galicia and consider the most appropriate antibiotics for empirical treatment. Retrospective study during the period 2011- 2012 of the isolation of E. coli in urine samples from almost all the Galician population. Demographic variables, minimum inhibitory concentration, and reading data were collected: amoxicillin-clavulanate, cefotaxime, gentamicin, amikacin, ciprofloxacin, cotrimoxazole, nitrofurantoin and fosfomycin. The identification and susceptibility studies were mainly conducted by automated systems. The interpretation of the results was performed according to CLSI criteria. During the study period 55,046 E. coli were isolated in UTI. The percentages of resistance were: cotrimoxazole, 30%; ciprofloxacin, 33%; amoxicillin-clavulanate, 23% and 10% for 3rd generation cephalosporins. Fosfomycin and nitrofurantoin showed the highest activity with more than 96% of susceptibility in our study. The linear trend of resistance regarding age was statistically significant (p Galicia, the most active antibiotics against E. coli associated with UTI are fosfomycin and nitrofurantoin so they should be considered as empirical treatment of choice by the community-acquired UTI not complicated by E. coli.
Susceptibility to paratuberculosis infection in cattle is associated withsingle nucleotide polymorphisms in Toll-like receptor 2 which modulate immune responses against Mycobacterium avium subspecies paratuberculosis
Koets, A; Santema, W; Oostenriik, D
Paratuberculosis is a chronic intestinal infection in ruminants, caused by Mycobacterium avium subspecies paratuberculosis (Map). To study the role of host genetics in disease susceptibility, the Toll-like receptor 2 (TLR2) gene, selected based on its potential role in immunity to mycobacterial...... infections, was analyzed for single nucleotide polymorphisms (SNP) and their potential association with disease. For SNP discovery and to study SNP association with disease, a case-control study including 24 cows from farms with paratuberculosis was conducted. Sequence analysis of the TLR2 genes from 12...... paratuberculosis-infected animals and 12 age-matched healthy herd mates revealed 21 different SNP. The TLR2-1903 T/C SNP was significantly associated with resistance to Map. This and four additional TLR2 SNP were studied in a subsequent observational field study with 553 cows from farms with paratuberculosis...
Full Text Available Fanconi anemia (FA is a recessive DNA repair disease characterized by a high predisposition to developing neoplasms. DNA tumor polyomavirus simian virus 40 (SV40 transforms FA fibroblasts at high efficiency suggesting that FA patients could be highly susceptible to SV40 infection. To test this hypothesis, the large tumor (LT antigen of SV40, BKV, JCV and Merkel Cell (MC polyomaviruses were tested in blood samples from 89 FA patients and from 82 of their parents. Two control groups consisting of 47 no-FA patients affected by other genetic bone marrow failure diseases and 91 healthy subjects were also evaluated. Although JCV, BKV and MC were not found in any of the FA samples, the prevalence and viral load of SV40 were higher in FA patients (25%; mean viral load: 1.1×10(2 copies/10(5cells as compared with healthy individuals (4.3%; mean viral load: 0.8×10(1 copies/10(5cells and genetic controls (0% (p<0.005. A marked age-dependent frequency of SV40 was found in FA with respect to healthy subjects suggesting that, although acquired early in life, the virus can widespread more easily in specific groups of population. From the analysis of family pedigrees, 60% of the parents of SV40-positive probands were positive for the virus compared to 2% of the parents of the SV40-negative probands (p<0.005. It is worthy of note that the relative frequency of SV40-positive relatives detected in this study was the highest ever reported, showing that asymptomatic FA carriers are also more susceptible to SV40. In conclusion, we favor the hypothesis that SV40 spread could be facilitated by individuals who are genetically more susceptible to infection, such as FA patients. The increased susceptibility to SV40 infection seems to be associated with a specific defect of the immune system which supports a potential interplay of SV40 with an underlying genetic alteration that increases the risk of malignancies.
Lewis, R; Behnke, J M; Stafford, P; Holland, C V
Ascaris suum and Ascaris lumbricoides exhibit an over-dispersed frequency distribution in their host populations in both the adult and larval stages. The impact of host factors on this observed distribution is still poorly understood and difficult to investigate in the natural host populations. The use of a mouse model has been supported by the observations that the larval migratory pattern, in this host, mimics the pattern observed in the pig. We explored the extrinsic factors that might affect the quantitative recovery of larvae during this migration in order to standardize a model system facilitating accurate future assessment of host genetic variation on this phase of the infection. In Exp. 1 larvae accumulated in the livers of both C57BL/6j and BALB/c mice up to and including days 4-5 p.i. and then declined in both strains until day 9. Loss of larvae from the livers corresponded to arrival in the lungs and maximum accumulation on day 7 p.i. but recovery was considerably higher in C57BL/6j mice. It was concluded that day 7 recoveries gave the best indication of relative resistance/susceptibility to this parasite. In Exp. 2 A/J, BALB/c, CBA/Ca, C57BL/6j, C3H/HeN, DBA/2, NIH, SJL, and SWR mice were compared. C57BL/6j mice were identified as the most susceptible strain and CBA/Ca mice as having the most contrasting phenotype, but with a similar kinetic pattern of migration. Finally, in Exp. 3, a strong positive correlation between the size of the inoculum and the mean worm recovery from the lungs was found in CBA/Ca and C57BL/6j mice, but the difference between these strains was highly consistent, 66.6-80%, regardless of the initial dose. These results demonstrate that, using our protocols for infection and recovery, between-experiment variation in A. suum worm burdens is minimal, and that C57BL/6j mice are highly susceptible to infection compared to other strains. The mechanistic basis of this susceptibility in relation to the resistance of other strains is
SMITH, ELIZABETH A.; Kumar, Sandeep R. P.; Deventhiran, Jagadeeswaran; Thomas E. Cecere; LeRoith, Tanya; McGilliard, Mike; Elankumaran, Subbiah; Mullarky, Isis Kanevsky
Bacterial superinfections following influenza A virus (IAV) are predominant causes of morbidity in humans. The recent emergence of methicillin-resistant Staphylococcus aureus (MRSA) and highly virulent IAV strains has reduced treatment options. Development of an appropriate animal model to study secondary S. aureus infections may provide important information regarding disease pathogenesis. Pigs are natural hosts to both IAV and S. aureus and have respiratory physiology and immune response co...
Ranjith, Konduri; Sontam, Bhavani; Sharma, Savitri; Joseph, Joveeta; Chathoth, Kanchana N; Sama, Kalyana C; Murthy, Somasheila I; Shivaji, Sisinthy
To determine the type of Candida species in ocular infections and to investigate the relationship of antifungal susceptibility profile to virulence factors. Fifty isolates of yeast-like fungi from patients with keratitis, endophthalmitis, and orbital cellulitis were identified by Vitek-2 compact system and DNA sequencing of ITS1-5.8S-ITS2 regions of the rRNA gene, followed by phylogenetic analysis for phenotypic and genotypic identification, respectively. Minimum inhibitory concentration of six antifungal drugs was determined by E test/microbroth dilution methods. Phenotypic and genotypic methods were used to determine the virulence factors. Phylogenetic analysis showed the clustering of all isolates into eight distinct groups with a major cluster formed Candida parapsilosis (n = 21), which was the most common species by both Vitek 2 and DNA sequencing. Using χ2 test no significant difference was noted between the techniques except that Vitek 2 did not identify C. viswanathii, C. orthopsilosis, and two non-Candida genera. Of 43 tested Candida isolates high susceptibility to amphotericin B (39/43, 90.6%) and natamycin (43/43, 100%) was noted. While none of the isolates produced coagulase, all produced esterase and catalase. The potential to form biofilm was detected in 23/43 (53.4%) isolates. Distribution of virulence factors by heat map analysis showed difference in metabolic activity of biofilm producers from nonbiofilm producers. Identified by Vitek 2 and DNA sequencing methods C. parapsilosis was the most common species associated with eye infections. Irrespective of the virulence factors elaborated, the Candida isolates were susceptible to commonly used antifungal drugs such as amphotericin B and natamycin.
Full Text Available Primary duck hepatocytes (PDH displays differential susceptibility to duck hepatitis B virus when maintained in the media supplemented with fetal bovine serum or dimethyl sulfoxide (DMSO which has been widely used for the maintenance of hepatocytes, and prolonging susceptibility to hepadnavirus. However the mechanism underlying maintenance of susceptibility to hepadnavirus by DMSO treatment remains unclear. In this study, a global transcriptome analysis of PDHs under different culture conditions was conducted for investigating the effects of DMSO on maintenance of susceptibility of PDH to DHBV in vitro. The 384 differential expressed genes (DEGs were identified by comparisons between each library pair (PDHs cultured with or without DMSO or fresh isolated PDH. We analyzed canonical pathways in which the DEGs were enriched in Hepatic Fibrosis / Hepatic Stellate Cell Activation, Bile Acid Biosynthesis and Tight Junction signaling. After re-annotation against human genome data, the 384 DEGs were pooled together with proteins belonging to hepatitis B pathway to construct a protein-protein interaction network. The combination of decreased expression of liver-specific genes (CYP3A4, CYP1E1, CFI, RELN and GSTA1 et al with increased expression of hepatocyte-dedifferentiation-associated genes (PLA2G4A and PLCG1 suggested that in vitro culture conditions results in the fading of hepatocyte phenotype in PDHs. The expression of seven DEGs associated with tight junction formation (JAM3, PPP2R2B, PRKAR1B, PPP2R2C, MAGI2, ACTA2 and ACTG2 was up-regulated after short-term culture in vitro, which was attenuated in the presence of DMSO. Those results could shed light on DHBV infection associated molecular events affected by DMSO.
Uzoamaka, Maduakor; Ngozi, Onyemelukwe; Johnbull, Ogboi Sonny; Martin, Ohanu
Lower respiratory tract infection (LRTI) is one of the common major health problems in Nigeria causing morbidity and mortality. The study was conducted to determine the current trends of bacterial etiology of LRTIs among patients who attended the University of Nigeria Teaching Hospital (UNTH) and their antimicrobial susceptibility profile with special interest on pandrug resistance. The study was conducted between February 2014 and June 2016 in the bacteriology laboratory of UNTH. Sputum samples of 954 patients with suspected LRTIs were received, after obtaining patients' informed consent and ethical clearance from the UNTH. The samples were collected and processed according to standard laboratory procedures. The mean age of the patients was 42.6 ± 16.8 years. Of the total 954 sputum samples, 431 (45.2%) were positive for micro-organisms. A single, unique pathogen was recovered in 415 patients (96.3%), and 16 (3.7%) were polymicrobial. The most predominant single pathogen was Klebsiella pneumoniae, 215 (49.9%), and the most prevalent bacterial combination was Klebsiella spp and Pseudomonas aeruginosa, 6 (1.4%). Antimicrobial susceptibility testing shows that most isolates of K pneumoniae were susceptible to imipenem (94.8%). Among the bacteria, Escherichia coli (13.3%) ranked highest, followed by P aeruginosa (12.5%), and the least was Staphylococcus aureus (2.1%). Knowledge of the diversity of pathogens responsible for LRTIs and their susceptibility patterns to antibiotics, as well as antibiotic resistance surveillance, are important in the effective management of LRTI with prompt clinical and laboratory diagnosis along with appropriate treatment strategies. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.
Full Text Available Dengue is a growing global concern with 390 million people infected each year. Dengue virus (DENV is transmitted by mosquitoes, thus host cells in the skin are the first point of contact with the virus. Human skin contains several populations of antigen-presenting cells which could drive the immune response to DENV in vivo: epidermal Langerhans cells (LCs, three populations of dermal dendritic cells (DCs, and macrophages. Using samples of normal human skin we detected productive infection of CD14(+ and CD1c(+ DCs, LCs and dermal macrophages, which was independent of DC-SIGN expression. LCs produced the highest viral titers and were less sensitive to IFN-β. Nanostring gene expression data showed significant up-regulation of IFN-β, STAT-1 and CCL5 upon viral exposure in susceptible DC populations. In mice infected intra-dermally with DENV we detected parallel populations of infected DCs originating from the dermis and migrating to the skin-draining lymph nodes. Therefore dermal DCs may simultaneously facilitate systemic spread of DENV and initiate the adaptive anti-viral immune response.
Eke, P I; Rotimi, V O; Laughon, B E
A virulence model suitable for studying the dynamics of Porphyromonas gingivalis infection, including the pathogenicity of P. gingivalis in experimentally induced infections of multiple organs was developed using mouse and hamster. Virulence of P. gingivalis strains was expressed contrastingly in subcutaneous (sc) infection in the Murine abscess model (MAM) and the Hamsters abscess model (HAM). Subcutaneous infection in the MAM was characterized by a gravity abscess, spreading from the primary site of inoculation downwards, frequently erupting as a secondary lesion. In contract, s.c. P. gingivalis infection in HAM was characterized as a palpable localized abscess at the primary site of inoculation. When the Semi-Solid Agar (SSA) was added to the mono-culture of P. gingivalis, reproducibility of infection in both models was enhanced. P. gingivalis culture supplemented with haemin, or combined with oral Actinomyces viscosus had its virulence overtly enhanced and often fatal in the MAM. Menadione, Eh reducing agents and mixture with the Streptococcus or A. neaslundii did not potentiate virulence in either mode. Transtracheal challenge of the lungs of hamster with P. gingivalis initiated an early pneumonitis and later sequelae of necrosis and abscess formation. Also, abscess was induced by direct inoculation of P. gingivalis in the muscles, liver and testes, but did not induce intra-abdominal abscesses. In conclusion, the HAM applied with the SSA procedure caused a localized P. gingivalis tissue infection with practical advantages for quantitative and qualitative studies of P. gingivalis infections. This study also demonstrates the pathogenic potential of P. gingivalis by reproducing similar infections in multiple anatomical sites.
Shah, Aftab A; Mihalj, Martina; Ratkay, Ivana; Lubka-Pathak, Maria; Balogh, Peter; Klingel, Karin; Bohn, Erwin; Blin, Nikolaus; Baus-Loncar, Mirela
TFF2 is one of the members of the trefoil factor family, known for its role in protection of gastrointestinal epithelia upon injury; however, recent studies suggest that TFF2 could also play an important role in the immune system. In the present study Tff2 deficient and wild type mice were infected by Y. enterocolitica which resulted in a lethal outcome in all Tff2 deficient mice, but not in WT animals. Yersinia invaded Peyer's patches more efficiently as shown by high bacterial titers in the KO mice while wild type mice displayed lower titers and a visible bacterial accumulation in the intestine. Bacterial accumulation in Peyer's patches of Tff2 deficient mice was accompanied by increased recruitment of macrophages. While an increased level of MAC-1 positive cells was observed in the spleens of both Tff2 deficient and WT mice at third day post infection, bacterial dissemination to liver, lung and kidneys was observed only in Tff2 knock-out mice. Analysis of the cellular composition of spleen did not reveal any substantial alteration to WT animals, suggesting possible disregulation of hemopoietic cells involved in immune response to Y. enterocolitica. These new data indicate that Tff2 plays an important role in immune response by protecting the organism from consequences of infection and that Tff2 knock-out mice react adversely to bacterial infections, in this case specifically to Y. enterocolitica. Copyright © 2012 S. Karger AG, Basel.
Boehnke, Kevin F; Eaton, Kathryn A; Valdivieso, Manuel; Baker, Laurence H; Xi, Chuanwu
Helicobacter pylori infection has been consistently associated with lack of access to clean water and proper sanitation, but no studies have demonstrated that the transmission of H. pylori can occur from drinking contaminated water. In this study, we used a laboratory mouse model to test whether waterborne H. pylori could cause gastric infection. Groups of immunocompetent C57/BL6 Helicobacter-free mice were exposed to static concentrations (1.29 × 10(5), 10(6), 10(7), 10(8), and 10(9) CFU/L) of H. pylori in their drinking water for 4 weeks. One group of Helicobacter-free mice was exposed to uncontaminated water as a negative control. H. pylori morphology changes in water were examined using microscopy Live/Dead staining. Following exposure, H. pylori infection and inflammation status in the stomach were evaluated using quantitative culture, PCR, the rapid urease test, and histology. None of the mice in the negative control or 10(5) groups were infected. One of 20 cages (one of 40 mice) of the 10(6) group, three of 19 cages (four of 38 mice) of the 10(7) CFU/L group, 19 of 20 cages (33 of 40 mice) of the 10(8) group, and 20 of 20 cages (39 of 40 mice) of the 10(9) CFU/L group were infected. Infected mice had significantly higher gastric inflammation than uninfected mice (27.86% higher inflammation, p pylori in water is infectious in mice, suggesting that humans drinking contaminated water may be at risk of contracting H. pylori infection. Much work needs to be performed to better understand the risk of infection from drinking H. pylori-contaminated water. © 2015 John Wiley & Sons Ltd.
Poeschl, Paul W; Crepaz, Valentina; Russmueller, Guenter; Seemann, Rudolf; Hirschl, Alexander M; Ewers, Rolf
The aims of the present study were to compare microbial populations in patients suffering from deep neck space abscesses caused by primary endodontic infections by sampling the infections with aspiration or swabbing techniques and to determine the susceptibility rates of the isolated bacteria to commonly used antibiotics. A total of 89 patients with deep neck space abscesses caused by primary endodontic infections requiring extraoral incision and drainage under general anesthesia were included. Either aspiration or swabbing was used to sample microbial pus specimens. The culture of the microbial specimens and susceptibility testing were performed following standard procedures. A total of 142 strains were recovered from 76 patients. In 13 patients, no bacteria were found. The predominant bacteria observed were streptococci (36%), staphylococci (13%), Prevotella (8%), and Peptostreptococcus (6%). A statistically significant greater number of obligate anaerobes were found in the aspiration group. The majority of patients presented a mixed aerobic-anaerobic population of bacterial flora (62%). The antibiotic resistance rates for the predominant bacteria were 10% for penicillin G, 9% for amoxicillin, 0% for amoxicillin clavulanate, 24% for clindamycin, and 24% for erythromycin. The results of our study indicated that a greater number of anaerobes were found when sampling using the aspiration technique. Penicillin G and aminopenicillins alone are not always sufficient for the treatment of severe deep neck space abscesses; beta-lactamase inhibitor combinations are more effective. Bacteria showed significant resistant rates to clindamycin. Thus, its single use in penicillin-allergic patients has to be carefully considered. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
Cabrera, Gabriel; Fernández-Brando, Romina J; Abrey-Recalde, María Jimena; Baschkier, Ariela; Pinto, Alipio; Goldstein, Jorge; Zotta, Elsa; Meiss, Roberto; Rivas, Marta; Palermo, Marina S
Enterohemorrhagic Escherichia coli (EHEC) is a food-borne pathogen that produces Shiga toxin (Stx) and causes hemorrhagic colitis. Under some circumstances, Stx produced within the intestinal tract enters the bloodstream, leading to systemic complications that may cause the potentially fatal hemolytic-uremic syndrome. Although retinoids like vitamin A (VA) and retinoic acid (RA) are beneficial to gut integrity and the immune system, the effect of VA supplementation on gastrointestinal infections of different etiologies has been controversial. Thus, the aim of this work was to study the influence of different VA status on the outcome of an EHEC intestinal infection in mice. We report that VA deficiency worsened the intestinal damage during EHEC infection but simultaneously improved survival. Since death is associated mainly with Stx toxicity, Stx was intravenously inoculated to analyze whether retinoid levels affect Stx susceptibility. Interestingly, while VA-deficient (VA-D) mice were resistant to a lethal dose of Stx2, RA-supplemented mice were more susceptible to it. Given that peripheral blood polymorphonuclear cells (PMNs) are known to potentiate Stx2 toxicity, we studied the influence of retinoid levels on the absolute number and function of PMNs. We found that VA-D mice had decreased PMN numbers and a diminished capacity to produce reactive oxygen species, while RA supplementation had the opposite effect. These results are in line with the well-known function of retinoids in maintaining the homeostasis of the gut but support the idea that they have a proinflammatory effect by acting, in part, on the PMN population. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
Full Text Available This study evaluates the presence of virulence factors and antibiotic susceptibility among enterococcal isolates from oral mucosal and deep infections. Forty-three enterococcal strains from oral mucosal lesions and 18 from deep infections were isolated from 830 samples that were sent during 2 years to Oral Microbiology, University of Gothenburg, for analysis. The 61 strains were identified by 16S rDNA, and characterized by the presence of the virulence genes efa A (endocarditis gene, gel E (gelatinase gene, ace (collagen binding antigen gene, asa (aggregation substance gene, cyl A (cytolysin activator gene and esp (surface adhesin gene, tested for the production of bacteriocins and presence of plasmids. MIC determination was performed using the E-test method against the most commonly used antibiotics in dentistry, for example, penicillin V, amoxicillin and clindamycin. Vancomycin was included in order to detect vancomycin-resistant enterococci (VRE strains. Sixty strains were identified as Enterococcus faecalis and one as Enterococcus faecium. All the virulence genes were detected in more than 93.3% (efa A and esp of the E. faecalis strains, while the presence of phenotypic characteristics was much lower (gelatinase 10% and hemolysin 16.7%. Forty-six strains produced bacteriocins and one to six plasmids were detected in half of the isolates. Enterococcal strains from oral infections had a high virulence capacity, showed bacteriocin production and had numerous plasmids. They were generally susceptible to ampicillins but were resistant to clindamycin, commonly used in dentistry, and no VRE-strain was found.
Sanchez-Migallon Guzman, David; Garcia, Valentina E.; Layton, Marylee L.; Hoon-Hanks, Laura L.; Boback, Scott M.; Keel, M. Kevin; Drazenovich, Tracy
.e., to identify organisms that appear to cause disease, but to be certain that a candidate pathogen actually causes disease, it is necessary to provide additional evidence of causality. We have done this to demonstrate that reptarenaviruses cause inclusion body disease (IBD), a serious transmissible disease of snakes. We infected boa constrictors and ball pythons with purified reptarenavirus. Ball pythons fell ill within 2 months of infection and displayed signs of neurological disease typical of IBD. In contrast, boa constrictors remained healthy over 2 years, despite high levels of virus throughout their bodies. This difference matches previous reports that pythons are more susceptible to IBD than boas and could reflect the possibility that boas are natural hosts of these viruses in the wild. PMID:28515291
Stenglein, Mark D; Sanchez-Migallon Guzman, David; Garcia, Valentina E; Layton, Marylee L; Hoon-Hanks, Laura L; Boback, Scott M; Keel, M Kevin; Drazenovich, Tracy; Hawkins, Michelle G; DeRisi, Joseph L
organisms that appear to cause disease, but to be certain that a candidate pathogen actually causes disease, it is necessary to provide additional evidence of causality. We have done this to demonstrate that reptarenaviruses cause inclusion body disease (IBD), a serious transmissible disease of snakes. We infected boa constrictors and ball pythons with purified reptarenavirus. Ball pythons fell ill within 2 months of infection and displayed signs of neurological disease typical of IBD. In contrast, boa constrictors remained healthy over 2 years, despite high levels of virus throughout their bodies. This difference matches previous reports that pythons are more susceptible to IBD than boas and could reflect the possibility that boas are natural hosts of these viruses in the wild. Copyright © 2017 Stenglein et al.
Susceptibility of freshwater snails to the amphistome Calicophoron microbothrium and the influence of the species on susceptibility of Bulinus tropicus to Schistosoma haematobium and Schistosoma mattheei infections.
Chingwena, Givemore; Mukaratirwa, Samson; Kristensen, Thomas K; Chimberi, Moses
The susceptibility of Bulinus tropicus, B. globosus, Biomphalana pfeifferi, Lymnaea natalensis, and Melanoides tuberculata to Calicophoron microbothrium was examined. Bulinus tropicus had the highest prevalence (65.0%), followed by B. pfeifferi (37.5%), B. globosus (6.8%), and M. tuberculata (5.9%). Lymnaea natalensis was refractory to infection. Bulinus tropicus snails infected with C. microbothrium alone or coinfected with either Schistosoma haematobium or S. mattheei 0, 7, 14, and 21 days after exposure to C. microbothrium produced C. microbothrium cercariae only.
Mayrhofer, S.; Konrad, J.D.; Amtmann, E.; Hoek, van A.H.A.M.; Petersson, A.; Mair, C.; Mayer, H.K.; Kneifel, W.
The widespread use of antimicrobial substances has led to resistant populations of microorganisms in several ecosystems. In animal husbandry, the application of antibiotics has contributed to resistance development in pathogenic and commensal bacteria. These strains or their resistance genes can be
Full Text Available Maria Teresa Mascellino,1 Barbara Porowska,2 Massimiliano De Angelis,1 Alessandra Oliva1 1Department of Public Health and Infectious Diseases, 2Department of Cardio-Thoracic, Vascular, General Surgery and of Organ Transplants, Policlinico Umberto I, Rome, Italy Abstract: In this review, we discuss the problem of antibiotic resistance, heteroresistance, the utility of cultures and antibiotic susceptibility tests in Helicobacter pylori (Hp eradication, as well as the updated treatment strategies for this infection. The prevalence of antibiotic resistance is increasing all over the world, especially for metronidazole and clarithromycin, because of their heavy use in some geographical areas. Heteroresistance (simultaneous presence of both susceptible and resistant strains in different sites of a single stomach is another important issue, as an isolate could be mistakenly considered susceptible if a single biopsy is used for antimicrobial tests. We also examined literature data regarding eradication success rates of culture-guided and empiric therapies. The empiric therapy and the one based on susceptibility testing, in Hp eradication, may depend on several factors such as concomitant diseases, the number of previous antibiotic treatments, differences in bacterial virulence in individuals with positive or negative cultures, together with local antibiotic resistance patterns in real-world settings. Updated treatment strategies in Hp infection presented in the guidelines of the Toronto Consensus Group (2016 are reported. These suggest to prolong eradication therapy up to 14 days, replacing the old triple therapy with a quadruple therapy based on proton pump inhibitor (PPI, bismuth, metronidazole, and tetracycline for most of the patients, or as an alternative quadruple therapy without bismuth, based on the use of PPI, amoxicillin, metronidazole, and clarithromycin. The new drug vonoprazan, a first-in-class potassium-competitive acid blocker recently
Mariné, Marçal; Bom, Vinicius Leite Pedro; de Castro, Patricia Alves; Winkelstroter, Lizziane Kretli; Ramalho, Leandra Naira; Brown, Neil Andrew; Goldman, Gustavo Henrique
The present study developed Galleria mellonella and murine infection models for the study of Trichosporon infections. The utility of the developed animal models was demonstrated through the assessment of virulence and antifungal efficacy for 7 clinical isolates of Trichosporon asahii, T. asteroides and T. inkin. The susceptibility of the Trichosporon isolates to several common antifungal drugs was tested in vitro using the broth microdilution and the E-test methods. The E-test method depicted a lower minimal inhibitory concentration (MIC) for amphotericin and a slightly higher MIC for caspofungin, while MICs observed for the azoles were different but comparable between both methods. All three Trichosporon species established infection in both the G. mellonella and immunosuppressed murine models. Species and strain dependent differences were observed in both the G. mellonella and murine models. T. asahii was demonstrated to be more virulent than the other 2 species in both animal hosts. Significant differences in virulence were observed between strains for T. asteroides in the murine model. In both animal models, fluconazole and voriconazole were able to improve the survival of the animals compared to the untreated control groups infected with any of the 3 Trichosporon species. In G. mellonella, amphotericin was not able to reduce mortality in any of the 3 species. In contrast, amphotericin was able to reduce murine mortality in the T. asahii or T. inkin models, respectively. Hence, the developed animal infection models can be directly applicable to the future deeper investigation of the molecular determinants of Trichosporon virulence and antifungal resistance.
López-Martínez, Briceida; Calderón-Jaimes, Ernesto; Olivar-López, Víctor; Parra-Ortega, Israel; Alcázar-López, Virginia; Castellanos-Cruz, María Del Carmen; de la Garza-López, Alicia
Urinary tract infection in children is well recognized as a cause of acute morbidity and chronic medical conditions. As a result, appropriate use of antimicrobial agents, however, increases antibiotic resistance and complicates its treatment due to increased patient morbidity, costs, rates of hospitalization, and use of broader-spectrum antibiotics. The goal of this study was to determine antibiotic susceptibility to commonly used agents for urinary tract infection against recent urinary isolates. A total of 457 consecutive children attending the emergency room at the Hospital Infantil de México Federico Gómez with symptoms of uncomplicated lower urinary tract infection were eligible for inclusion. Patients who had had symptoms for≥7 days and those who had had previous episodes of urinary tract infection, received antibiotics or other complicated factors were excluded. Midstream and catheter urine specimens were collected. All isolates were identified and the in vitro activities of antimicrobials were determined. The most frequently isolated urinary pathogens were as follows: Escherichia coli (E. coli) (312, 68.3%), Enterococcus spp. (42, 11%), Klebsiella pneumoniae (K. pneumoniae) (40, 8.7%), Pseudomonas aeruginosa (P. aeruginosa) (34, 7.5%), Proteus mirabilis (P. mirabilis) (21, 4.5%), Enterobacter cloacae (8, 1.7%). The resistance to trimetoprim/sulfametoxazol (%) was 73.7, 62.2, 100, 52, and 50, respectively, for E. coli, K. pneumoniae, P. aeruginosa, P. mirabilis and Enterobacter spp., 92.5 for Enterococcus faecalis (E. faecalis) and 49.9 for Enterococcus faecium (E. faecium). Ampicillin was 86.3, 45, 100, 47.9, and 66.6% for the same strains, ciprofloxacin 33.8, 9, 18.8, 0, 0%, nitrofurantoin 4.4, 13, 97.7, 70, 0%; to E. faecalis 0% and 16.7% to E. faecium. Frequently prescribed empirical agents for uncomplicated urinary tract infection demonstrate lowered in vitro susceptibilities when tested against recent clinical isolates. Copyright © 2014 Hospital
Morrison, Thomas E; Diamond, Michael S
Zika virus (ZIKV) is an emerging mosquito-transmitted flavivirus that now causes epidemics affecting millions of people on multiple continents. The virus has received global attention because of some of its unusual epidemiological and clinical features, including persistent infection in the male reproductive tract and sexual transmission, an ability to cross the placenta during pregnancy and infect the developing fetus to cause congenital malformations, and its association with Guillain-Barré syndrome in adults. This past year has witnessed an intensive effort by the global scientific community to understand the biology of ZIKV and to develop pathogenesis models for the rapid testing of possible countermeasures. Here, we review the recent advances in and utility and limitations of newly developed mouse and nonhuman primate models of ZIKV infection and pathogenesis. Copyright © 2017 American Society for Microbiology.
ABSTRACT Zika virus (ZIKV) is an emerging mosquito-transmitted flavivirus that now causes epidemics affecting millions of people on multiple continents. The virus has received global attention because of some of its unusual epidemiological and clinical features, including persistent infection in the male reproductive tract and sexual transmission, an ability to cross the placenta during pregnancy and infect the developing fetus to cause congenital malformations, and its association with Guillain-Barré syndrome in adults. This past year has witnessed an intensive effort by the global scientific community to understand the biology of ZIKV and to develop pathogenesis models for the rapid testing of possible countermeasures. Here, we review the recent advances in and utility and limitations of newly developed mouse and nonhuman primate models of ZIKV infection and pathogenesis. PMID:28148798
Li, Junqiang; Wang, Haiyan; Wang, Rongjun; Zhang, Longxian
Giardia duodenalis is an important zoonotic pathogen in both public and veterinary health, and has been genotyped into at least eight assemblages (A–H), each with a distinct host range. In recent years, this intestinal protozoan parasite has been identified widely in humans and various other animals, and has even been recorded in environmental contaminants. Along with whole genome sequencing of G. duodenalis, multilocus sequence typing is increasingly being used to characterize G. duodenalis isolates. Here, we review the epidemiology, genotyping, and subtyping of G. duodenalis from humans and a wide range of other animals, as well as from wastewater, in China. PMID:29081771
Full Text Available Giardia duodenalis is an important zoonotic pathogen in both public and veterinary health, and has been genotyped into at least eight assemblages (A–H, each with a distinct host range. In recent years, this intestinal protozoan parasite has been identified widely in humans and various other animals, and has even been recorded in environmental contaminants. Along with whole genome sequencing of G. duodenalis, multilocus sequence typing is increasingly being used to characterize G. duodenalis isolates. Here, we review the epidemiology, genotyping, and subtyping of G. duodenalis from humans and a wide range of other animals, as well as from wastewater, in China.
Roy, Sabita; Ninkovic, Jana; Banerjee, Santanu; Charboneau, Richard Gene; Das, Subhas; Dutta, Raini; Kirchner, Varvara A; Koodie, Lisa; Ma, Jing; Meng, Jingjing; Barke, Roderick A
Infection rate among intravenous drug users (IDU) is higher than the general public, and is the major cause of morbidity and hospitalization in the IDU population. Epidemiologic studies provide data on increased prevalence of opportunistic bacterial infections such as TB and pneumonia, and viral infections such as HIV-1 and hepatitis in the IDU population. An important component in the intravenous drug abuse population and in patients receiving medically indicated chronic opioid treatment is opioid withdrawal. Data on bacterial virulence in the context of opioid withdrawal suggest that mice undergoing withdrawal had shortened survival and increased bacterial load in response to Salmonella infection. As the body of evidence in support of opioid dependency and its immunosuppressive effects is growing, it is imperative to understand the mechanisms by which opioids exert these effects and identify the populations at risk that would benefit the most from the interventions to counteract opioid immunosuppressive effects. Thus, it is important to refine the existing animal model to closely match human conditions and to cross-validate these findings through carefully controlled human studies. Better understanding of the mechanisms will facilitate the search for new therapeutic modalities to counteract adverse effects including increased infection rates. This review will summarize the effects of morphine on innate and adaptive immunity, identify the role of the mu opioid receptor in these functions and the signal transduction activated in the process. The role of opioid withdrawal in immunosuppression and the clinical relevance of these findings will also be discussed.
Vázquez Diego P
Full Text Available We tested experimentally the effects of the presence of non-susceptible hosts on the infection with Trypanosoma cruzi of the vector Triatoma infestans. The experiment consisted in two treatments: with chickens, including two chickens (non-susceptible hosts and two infected guinea pigs (susceptible hosts, and without chickens, including only two infected guinea pigs. The hosts were held unrestrained in individual metal cages inside a closed tulle chamber. A total of 200 uninfected T. infestans third instar nymphs were liberated in each replica, collected on day 14, and examined for infection and blood meal sources on day 32-36. The additional presence of chickens relative to infected guinea pigs: (a significantly modified the spatial distribution of bugs; (b increased significantly the likelihoods of having a detectable blood meal on any host and molting to the next instar; (c did not affect the bugs' probability of death by predation; and (d decreased significantly the overall percentage of T. infestans infected with T. cruzi. The bugs collected from inside or close to the guinea pigs' cages showed a higher infection rate (71-88% than those collected from the chickens' cages (22-32%. Mixed blood meals on chickens and guinea pigs were detected in 12-21% of bugs. Although the presence of chickens would decrease the overall percentage of infected bugs in short term experiments, the high rate of host change of T. infestans would make this difference fade out if longer exposure times had been provided.
Jamie I MacPherson
Full Text Available Hepatitis C virus (HCV is a global problem. To better understand HCV infection researchers employ in vitro HCV cell-culture (HCVcc systems that use Huh-7 derived hepatoma cells that are particularly permissive to HCV infection. A variety of hyper-permissive cells have been subcloned for this purpose. In addition, subclones of Huh-7 which have evolved resistance to HCV are available. However, the mechanisms of susceptibility or resistance to infection among these cells have not been fully determined. In order to elucidate mechanisms by which hepatoma cells are susceptible or resistant to HCV infection we performed genome-wide expression analyses of six Huh-7 derived cell cultures that have different levels of permissiveness to infection. A great number of genes, representing a wide spectrum of functions are differentially expressed between cells. To focus our investigation, we identify host proteins from HCV replicase complexes, perform gene expression analysis of three HCV infected cells and conduct a detailed analysis of differentially expressed host factors by integrating a variety of data sources. Our results demonstrate that changes relating to susceptibility to HCV infection in hepatoma cells are linked to the innate immune response, secreted signal peptides and host factors that have a role in virus entry and replication. This work identifies both known and novel host factors that may influence HCV infection. Our findings build upon current knowledge of the complex interplay between HCV and the host cell, which could aid development of new antiviral strategies.
Moy, Terence I; Conery, Annie L; Larkins-Ford, Jonah; Wu, Gang; Mazitschek, Ralph; Casadei, Gabriele; Lewis, Kim; Carpenter, Anne E; Ausubel, Frederick M
The nematode Caenorhabditis elegans is a unique whole animal model system for identifying small molecules with in vivo anti-infective properties. C. elegans can be infected with a broad range of human pathogens, including Enterococcus faecalis, an important human nosocomial pathogen. Here, we describe an automated, high-throughput screen of 37,200 compounds and natural product extracts for those that enhance survival of C. elegans infected with E. faecalis. Using a robot to dispense live, infected animals into 384-well plates and automated microscopy and image analysis, we identified 28 compounds and extracts not previously reported to have antimicrobial properties, including six structural classes that cure infected C. elegans animals but do not affect the growth of the pathogen in vitro, thus acting by a mechanism of action distinct from antibiotics currently in clinical use.
Full Text Available Implant related infection following spine surgery is a devastating complication for patients and can potentially lead to significant neurological compromise, disability, morbidity, and even mortality. This paper provides an overview of the existing animal models of postoperative spine infection and highlights the strengths and weaknesses of each model. In addition there is discussion regarding potential modifications to these animal models to better evaluate preventative and treatment strategies for this challenging complication. Current models are effective in simulating surgical procedures but fail to evaluate infection longitudinally using multiple techniques. Potential future modifications to these models include using advanced imaging technologies to evaluate infection, use of bioluminescent bacterial species, and testing of novel treatment strategies against multiple bacterial strains. There is potential to establish a postoperative spine infection model using smaller animals, such as mice, as these would be a more cost-effective screening tool for potential therapeutic interventions.
Stavrakis, A I; Loftin, A H; Lord, E L; Hu, Y; Manegold, J E; Dworsky, E M; Scaduto, A A; Bernthal, N M
Implant related infection following spine surgery is a devastating complication for patients and can potentially lead to significant neurological compromise, disability, morbidity, and even mortality. This paper provides an overview of the existing animal models of postoperative spine infection and highlights the strengths and weaknesses of each model. In addition, there is discussion regarding potential modifications to these animal models to better evaluate preventative and treatment strategies for this challenging complication. Current models are effective in simulating surgical procedures but fail to evaluate infection longitudinally using multiple techniques. Potential future modifications to these models include using advanced imaging technologies to evaluate infection, use of bioluminescent bacterial species, and testing of novel treatment strategies against multiple bacterial strains. There is potential to establish a postoperative spine infection model using smaller animals, such as mice, as these would be a more cost-effective screening tool for potential therapeutic interventions.
Stupar, P; Opota, O; Longo, G; Prod'hom, G; Dietler, G; Greub, G; Kasas, S
The management of bloodstream infection, a life-threatening disease, largely relies on early detection of infecting microorganisms and accurate determination of their antibiotic susceptibility to reduce both mortality and morbidity. Recently we developed a new technique based on atomic force microscopy capable of detecting movements of biologic samples at the nanoscale. Such sensor is able to monitor the response of bacteria to antibiotic's pressure, allowing a fast and versatile susceptibility test. Furthermore, rapid preparation of a bacterial pellet from a positive blood culture can improve downstream characterization of the recovered pathogen as a result of the increased bacterial concentration obtained. Using artificially inoculated blood cultures, we combined these two innovative procedures and validated them in double-blind experiments to determine the susceptibility and resistance of Escherichia coli strains (ATCC 25933 as susceptible and a characterized clinical isolate as resistant strain) towards a selection of antibiotics commonly used in clinical settings. On the basis of the variance of the sensor movements, we were able to positively discriminate the resistant from the susceptible E. coli strains in 16 of 17 blindly investigated cases. Furthermore, we defined a variance change threshold of 60% that discriminates susceptible from resistant strains. By combining the nanomotion sensor with the rapid preparation method of blood culture pellets, we obtained an innovative, rapid and relatively accurate method for antibiotic susceptibility test directly from positive blood culture bottles, without the need for bacterial subculture. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
J.D.W. Philippa (Joost)
markdownabstract__Abstract__ Since the 1980's, emerging and re-emerging infectious diseases have made an enormous impact on public and animal health, food supply, economies, and the environment. An estimated 75% of emerging infectious diseases in humans are zoonotic (pathogens of non-human
Holsback, Luciane; Cardoso, Mauro José Lahm; Fagnani, Rafael; Patelli, Thaís Helena Constantino
The objective of this study was to investigate the frequency of occurrence and variety of intestinal parasites among free-living wild animals. Fecal samples from wild mammals and birds at rehabilitation centers in the states of Mato Grosso do Sul and São Paulo were analyzed by sedimentation and flotation-centrifugation methods. Parasite eggs, oocysts, cysts and/or trophozoites were found in 71% of the samples. Cryptosporidium sp. oocysts were detected in fecal samples from oncillas (Leopardus tigrinus) and scaly-headed parrots (Pionus maximiliani). Giardia cysts were identified in the feces of a gray brocket (Mazama gouazoubira). Among the most common parasites found, there were eggs from Toxocara cati, Toxascaris leonina and Ancylostoma tubaeforme, and from Cestoda. Several Enterobius sp. eggs were found in the feces of red howler monkeys (Alouatta seniculus). It can be concluded from this study that despite the small number of samples, the diversity of parasites found was noteworthy. Additional information about parasite endofauna in wild animals is needed, since their presence might suggest that there could be proximity to and interactions with domestic animals and/or humans. In addition, further studies on parasites from free-living wild animals are of prime importance for understanding the intensity of anthropic changes in wild environments.
de Almeida Leal, Gleisiane Gomes; Roatt, Bruno Mendes; de Oliveira Aguiar-Soares, Rodrigo Dian; Carneiro, Cláudia Martins; Giunchetti, Rodolfo Cordeiro; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis; Francisco, Amanda Fortes; Cardoso, Jamille Mirelle; Mathias, Fernando Augusto Siqueira; Correa-Oliveira, Rodrigo; Carneiro, Mariângela; Coura-Vital, Wendel; Reis, Alexandre Barbosa
Visceral leishmaniasis has a great impact on public health, and dogs are considered the main domestic reservoir of Leishmania infantum, the causal parasite. In this study, 159 animals naturally infected by L. infantum from an endemic area of Brazil were evaluated through an analysis of cellular responses, using flow cytometry, and of the hematological parameters. The results confirmed that disease progression is associated with anemia and reductions in eosinophils, monocytes and lymphocytes. The investigation of the immune response, based on the immunophenotypic profile of peripheral blood, showed declines in the absolute numbers of T lymphocytes CD5(+) and their subsets (CD4(+) and CD8(+)) and a drop of B lymphocytes in asymptomatic seropositive (AD-II) and symptomatic seropositive (SD) dogs. Neutrophils, when stimulated with soluble antigen of L. infantum, showed higher synthesis of interferon (IFN)-γ(+) in AD-II and SD groups, with decreased production of interleukin (IL)-4(+) in asymptomatic seronegative dogs positive for L. infantum infection based on polymerase chain reaction testing (AD-I group). In the AD-II and SD groups, subpopulations of stimulated lymphocytes (CD4(+) and CD8(+)) also exhibited greater synthesis of IFN-γ(+) and IL-4(+) in culture. These results suggest that the animals of the AD-II and SD groups exhibited a mixed immune response (Type 1 and 2) and the AD-I group presenting an immune profile very similar to normal control animals. Copyright © 2014 Elsevier B.V. All rights reserved.
Albariño César G
Full Text Available Abstract Background Rift Valley Fever Virus is a pathogen of humans and livestock that causes significant morbidity and mortality throughout Africa and the Middle East. A vaccine that would protect animals from disease would be very beneficial to the human population because prevention of the amplification cycle in livestock would greatly reduce the risk of human infection by preventing livestock epizootics. A mutant virus, constructed through the use of reverse genetics, is protective in laboratory animal models and thus shows promise as a potential vaccine. However, the ability to distinguish infected from vaccinated animals is important for vaccine acceptance by national and international authorities, given regulations restricting movement and export of infected animals. Results In this study, we describe the development of a simple assay that can be used to distinguish naturally infected animals from ones that have been vaccinated with a mutant virus. We describe the cloning, expression and purification of two viral proteins, and the development of side by side ELISAs using the two viral proteins. Conclusion A side by side ELISA can be used to differentiate infected from vaccinated animals. This assay can be done without the use of biocontainment facilities and has potential for use in both human and animal populations.
Ji, Shenggong; Lü, Linyuan; Yeung, Chi Ho; Hu, Yanqing
Social networks constitute a new platform for information propagation, but its success is crucially dependent on the choice of spreaders who initiate the spreading of information. In this paper, we remove edges in a network at random and the network segments into isolated clusters. The most important nodes in each cluster then form a set of influential spreaders, such that news propagating from them would lead to extensive coverage and minimal redundancy. The method utilizes the similarities between the segmented networks before percolation and the coverage of information propagation in each social cluster to obtain a set of distributed and coordinated spreaders. Our tests of implementing the susceptible-infected-recovered model on Facebook and Enron email networks show that this method outperforms conventional centrality-based methods in terms of spreadability and coverage redundancy. The suggested way of identifying influential spreaders thus sheds light on a new paradigm of information propagation in social networks.
Wang, Wei; Zhong, Lin-Feng; Tang, Ming; Gao, Hui; Stanley, H Eugene
Researchers have developed several theoretical methods for predicting epidemic thresholds, including the mean-field like (MFL) method, the quenched mean-field (QMF) method, and the dynamical message passing (DMP) method. When these methods are applied to predict epidemic threshold they often produce differing results and their relative levels of accuracy are still unknown. We systematically analyze these two issues---relationships among differing results and levels of accuracy---by studying the susceptible-infected-recovered (SIR) model on uncorrelated configuration networks and a group of 56 real-world networks. In uncorrelated configuration networks the MFL and DMP methods yield identical predictions that are larger and more accurate than the prediction generated by the QMF method. When compared to the 56 real-world networks, the epidemic threshold obtained by the DMP method is closer to the actual epidemic threshold because it incorporates full network topology information and some dynamical correlations. ...
Chen, Lihong; Wei, Fengying
In this paper, the dynamics of a stochastic susceptible-infected-removed model in a population with varying size is investigated. We firstly show that the stochastic epidemic model has a unique global positive solution with any positive initial value. Then we verify that random perturbations lead to extinction when some conditions are being valid. Moreover, we prove that the solution of the stochastic epidemic model is persistent in the mean by building up a suitable Lyapunov function and using generalized Itô's formula. Further, the stochastic epidemic model admits a stationary distribution around the endemic equilibrium when parameters satisfy some sufficient conditions. To end this contribution and to check the validity of the main results, numerical simulations are separately carried out to illustrate these results.
Krzyściak, Paweł; Chmielarczyk, Agnieszka; Pobiega, Monika; Romaniszyn, Dorota; Wójkowska-Mach, Jadwiga
Acinetobacter baumannii cause opportunistic nosocomial infections and is often multidrug resistant. It has ability to form biofilm. The possession of drug resistance mechanism and ability of biofilm formation seems to be the different way to enhancement of viability in stressful environment. In this study, we evaluate relation between these two factors. The biofilm formation was investigated in M63 medium with casein in microtiter plates, and the drug susceptibility was performed by disk diffusion methods. We found that 80-98% strains formed a biofilm. Strains showing sensitivity to amikacin and tobramycin from ICU produced more biofilm than strains showing resistance to these antibiotics. Ceftazidime-sensitive strains formed a smaller biofilm than resistant. The logistic regression shows association between drug resistance and strains originating from ICU. In case of ceftazidime, strong biofilm formation and descending from ICU reduced the likelihood of drug sensitivity. For other drugs such as aminoglycosides, fluoroquinolones, trimethoprim/sulfamethoxazole, and tetracycline, we found opposite relation (but it was not statistically significance). However, generally it seems that strong biofilm producers from ICUs are often more susceptible to antibiotics. This situation can be explained by the fact that bacteria protected in biofilm do not need mechanisms responsible for resistance of planktonic cells. © 2017 APMIS. Published by John Wiley & Sons Ltd.
McGarvey, Stephen T.; Carabin, Hélène; Batalong, Ernesto Jr.
To estimate the association between the intensity of animal infection with Schistosoma japonicum and human infection in Western Samar province, the Philippines......To estimate the association between the intensity of animal infection with Schistosoma japonicum and human infection in Western Samar province, the Philippines...
Robben, S.R.; Nobel, le W.E.; Dopfer, D.D.V.; Hendrikx, W.M.; Boersema, J.H.; Fransen, F.; Eysker, M.
To determine the prevalence of infections with helminths and protozoa in cats in animal shelters, faecal samples from 305 cats from 22 animal shelters in the Netherlands were examined, using a centrifugation-sedimentation-flotation-technique. The association between potential risk factors and the
Full Text Available Brachylaima cribbi is a terrestrial trematode of birds and mammals with helic id and hygromild land snails reported as first and second Intermediate hosts. However, reports describing the first Intermediate host range of B. cribbi have been limited to those snail species present In a small number of geographical locations In South Australia. The natural first Intermediate host range, distribution and prevalence of B. cribbi In land snails In southern Australia were determined. A total of 6,432 introduced and native land snails were collected from eight geographical districts across 3,000 km of southern Australia and examined microscopically for B. cribbi sporocysts. Four Introduced European snails, Theba pisana, Cernuella virgata, Cochlicella acuta and Cochlicella barbara were natural first Intermediate hosts. Sporocyst-infected snails were detected In all districts from Victoria to the west coast of South Australia, a distance of over 1,300 km. Natural sporocyst infection was not observed in introduced European snails Microxeromagna armillata and Helix aspersa or In native Australian land snails Succinea australis and Strangesta gawleri. Egg feeding experiments in the laboratory with B. cribbi confirmed the susceptibility of those species of snails found to be natural first intermediate hosts. Of those species not found to be Infected In nature, only M. armillata could be Infected In the laboratory. Although this study has shown that five different species of European land snails are suitable first Intermediate hosts for B. cribbi there are as yet no reports of B. cribbi from these snails In Europe or from other countries where they have been introduced. Further Investigations are needed in Europe to clarify the origins of this parasite.
Rodrigues, Rosângela Maria; Cardoso, Cristina Ribeiro; Gonçalves, Ana Lúcia Ribeiro; Silva, Neide Maria; Massa, Virgínia; Alves, Ronaldo; Ueta, Marlene Tiduko; Silva, João Santana; Costa-Cruz, Julia Maria
In human and murine models strongyloidiasis induce a Th2 type response. In the current study we investigated the role of different loads of Strongyloides venezuelensis in the immune response raised against the parasite and the participation of the major histocompatibility complex (MHC) class II molecule in the disease outcome in face of the different parasite burden. The C57BL/6 wild type (WT) and MHC II(-/-) mice were individually inoculated by subcutaneous injection with 500 or 3000 S. venezuelensis L3. The MHC II(-/-) mice infected with 3000L3 were more susceptible to S. venezuelensis infection when compared with WT groups, in which the parasite was completely eliminated. The production of Th2 cytokines and specific IgG1 or IgE antibodies against parasite were significantly lowered in MHC II(-/-) infected mice with different larvae inoculums. The infection of MHC II(-/-) mice with S. venezuelensis induced slight inflammatory alterations in the small intestine, and these lesions were lower when compared with WT mice, irrespective of the parasite load utilized to infect animals. Finally, we concluded that MHC class II molecules are essential in the immune response against S. venezuelensis mainly when infection occurs with high parasite inoculum. Copyright © 2013 Elsevier Inc. All rights reserved.
Ching Wen Tseng
Full Text Available Staphylococcus aureus is a leading cause of skin and soft-tissue infections worldwide. Mice are the most commonly used animals for modeling human staphylococcal infections. However a supra-physiologic S. aureus inoculum is required to establish gross murine skin pathology. Moreover, many staphylococcal factors, including Panton-Valentine leukocidin (PVL elaborated by community-associated methicillin-resistant S. aureus (CA-MRSA, exhibit selective human tropism and cannot be adequately studied in mice. To overcome these deficiencies, we investigated S. aureus infection in non-obese diabetic (NOD/severe combined immune deficiency (SCID/IL2rγnull (NSG mice engrafted with human CD34+ umbilical cord blood cells. These "humanized" NSG mice require one to two log lower inoculum to induce consistent skin lesions compared with control mice, and exhibit larger cutaneous lesions upon infection with PVL+ versus isogenic PVL- S. aureus. Neutrophils appear important for PVL pathology as adoptive transfer of human neutrophils alone to NSG mice was sufficient to induce dermonecrosis following challenge with PVL+ S. aureus but not PVL- S. aureus. PMX53, a human C5aR inhibitor, blocked PVL-induced cellular cytotoxicity in vitro and reduced the size difference of lesions induced by the PVL+ and PVL- S. aureus, but PMX53 also reduced recruitment of neutrophils and exacerbated the infection. Overall, our findings establish humanized mice as an important translational tool for the study of S. aureus infection and provide strong evidence that PVL is a human virulence factor.
Pouladfar, Gholamreza; Basiratnia, Mitra; Anvarinejad, Mojtaba; Abbasi, Pejman; Amirmoezi, Fatemeh; Zare, Samaneh
Urinary tract infection (UTI) is one of the most common bacterial infections in pediatrics. Delay in diagnosis and treatment can cause significant morbidity. The physicians knowledge regarding the symptoms, microorganisms that caused UTI, and effective antibiotics in a geographical area can help them to select the appropriate antibiotics. This study was performed to determine the prevalence of bacteria that cause UTI and their susceptibility to common antibiotics as well as the common symptoms and associated factors in children of Shiraz, Southern Iran.This cross sectional study was performed among 202 children with UTI, aged 2 months to 18 years old, between August and November 2014 in pediatric medical centers of Shiraz University of Medical Sciences. Urine samples were collected using urinary catheter or suprapubic in children antibiotic susceptibility for each organism was assayed by the Kirby Bauer method using antibiogram test. Patient's information was collected through checking the medical documents and interview with parents.Our results showed that the frequency of UTI was significantly higher in girls (70.3%) than in boys. The most commonly discovered pathogens were Escherichia coli (E coli) (51.5%), followed by Klebsiella spp. (16.8%), and Enterococcus spp. (9.9%). Overall susceptibility test showed the highest resistance to ampicillin (81.2%) and cotrimoxazole (79.2%), and the highest sensitivity to imipenem (90.1%) and Gentamicin (65.3%). Gram negative and positive bacteria showed the highest antibiotic resistance to amoxicillin (83.8%) and clindamycin (100%), respectively. In addition, production of extended spectrum beta lactamase (ESBL) was 69.2% and 30.8% in E coli and Kelebsiella respectively.The efficacy of third generation of the cephalosporins was reduced because of the high rate of production of ESBL and drug resistance. These results inform the physician as to which antibiotics are appropriate to prescribe for the patient, as well as urine
Inder Singh, K; Krishnasamy, M; Ambu, S; Rasul, R; Chong, N L
Surveillance studies on cercarial dermatitis were carried out in paddy growing areas in Peninsular Malaysia. It was observed that dermatitis in paddy planters occurred in paddy fields which were cultivated using animals such as bafflos or fields where domestic animals were allowed to graze during the off planting season as these animals harbored the parasite. The causative agent of cercarial dermatitis was Schistosoma spindale. A total of 215 small mammals trapped from Alor Setar and 126 trapped from Labu were examined for the schistosome. In Alor Setar Bandicota indica, Rattus argentiventer and Rattus rattus diardii were the only wild mammals found to be infected with the parasite, while in the Labu areas only Rattus tiomanicus jalorensis was positive for the schistosome. The occurrence of S. spindale in R. argentiventer and R.r. diardii in Alor Setar and in R.t. jalorensis in Labu constitute new host and geographic distribution records of the schistosome.
Margarida D Duarte
Full Text Available The exposure of wild carnivores to viral pathogens, with emphasis on parvovirus (CPV/FPLV, was assessed based on the molecular screening of tissue samples from 128 hunted or accidentally road-killed animals collected in Portugal from 2008 to 2011, including Egyptian mongoose (Herpestes ichneumon, n = 99, red fox (Vulpes vulpes, n = 19, stone marten (Martes foina, n = 3, common genet (Genetta genetta, n = 3 and Eurasian badger (Meles meles, n = 4. A high prevalence of parvovirus DNA (63% was detected among all surveyed species, particularly in mongooses (58% and red foxes (79%, along with the presence of CPV/FPLV circulating antibodies that were identified in 90% of a subset of parvovirus-DNA positive samples. Most specimens were extensively autolysed, restricting macro and microscopic investigations for lesion evaluation. Whenever possible to examine, signs of active disease were not present, supporting the hypothesis that the parvovirus vp2 gene fragments detected by real-time PCR possibly correspond to viral DNA reminiscent from previous infections. The molecular characterization of viruses, based on the analysis of the complete or partial sequence of the vp2 gene, allowed typifying three viral strains of mongoose and four red fox's as feline panleukopenia virus (FPLV and one stone marten's as newCPV-2b type. The genetic similarity found between the FPLV viruses from free-ranging and captive wild species originated in Portugal and publicly available comparable sequences, suggests a closer genetic relatedness among FPLV circulating in Portugal. Although the clinical and epidemiological significance of infection could not be established, this study evidences that exposure of sympatric wild carnivores to parvovirus is common and geographically widespread, potentially carrying a risk to susceptible populations at the wildlife-domestic interface and to threatened species, such as the wildcat (Felis silvestris and the critically
Zhang, Xin; He, Chuan-Chuan; Liu, Jin-Ming; Li, Hao; Lu, Ke; Fu, Zhi-Qiang; Zhu, Chuan-Gang; Liu, Yi-Ping; Tong, Lai-Bao; Zhou, De-Bao; Zha, Li; Hong, Yang; Jin, Ya-Mei; Lin, Jiao-Jiao
Schistosomiasis japonica is a common zoonosis. Domestic animals are the primary source of infection and play an important role in disease transmission. The prevalence and infectivity of this disease in domestic animals in China have significantly decreased and, for this reason, diagnostics with a higher sensitivity have become increasingly necessary. It was reported that polymerase chain reaction (PCR)-based methods could be used to detect schistosome infection in humans and animals and presented a high sensitivity and specificity. The present study aimed to develop a PCR-based method for detection of Schistosoma japonicum infection in domestic animals. A specific nested-PCR assay was developed to detect S. japonicum infection in domestic animals via amplification of a 231-bp DNA fragment of retrotransposon SjR2. The developed assay was first used in sera and dry blood filter paper (DBFP) from goats and buffaloes at different time points of infection. Then, 78 DBFPs from 39 artificially-infected bovines at 14 and 28 days post-infection and 42 DBFPs from schistosome-negative bovines from the city of Huangshan in the Anhui province were used to evaluate the diagnostic validity. Furthermore, this assay was used to detect S. japonicum infection in domestic animals in Dongzhi and Wangjiang counties. The expected PCR product was detected in eggs and adult worms of S. japonicum and blood samples from S. japonicum-infected goats and water buffaloes, but not from Fasciola and Haemonchus contortus worms. The nested-PCR assay could detect the target S. japonicum DNA in DBFPs from goats and buffaloes after day 3 post-infection. The sensitivity in buffaloes at 14 and 28 days post-infection was 92.30% (36/39) and 100% (39/39), respectively. The specificity was 97.60% (41/42). The positivity rates in Dongzhi and Wangjiang counties were 6.00% and 8.00% in bovines and 22.00% and 16.67% in goats, respectively. The positivity rates in goats in both counties were higher than those
Gilmour, M.I.; Selgrade, M.K. (Univ. of North Carolina, Chapel Hill (United States))
Ozone (O3) exposure reduces alveolar macrophage (AM) phagocytosis in mice and increases their susceptibility to Streptococcus zooepidemicus. O3 exposure also decreases AM phagocytosis in rats but does not result in mortality to infection. To investigate the mechanism of disease protection in rats, antibacterial defenses of two strains of mice and F344 rats were compared. O3 exposure (3 hr, 0.4 or 0.8 ppm) and infection with S. zooepidemicus resulted in a dose-dependent proliferation of bacteria in the lungs of mice and high mortality. Polymorphonuclear leukocytes (PMNs) were observed in severely affected individuals 2 or more days postinfection and did not alter the fatal infection. In contrast, microbial inactivation was only impaired in O3-exposed rat lungs during the first 48 hr after infection. In these animals PMNs could be isolated from bronchoalveolar lavage fluid between 6 and 48 hr postinfection with the peak response occurring at 24 hr. Pretreatment with anti-PMN serum eliminated the neutrophil influx and impaired further the bactericidal activity in ozone-exposed rats. The results suggest that inhaled streptococci are cleared normally from the mouse lung by AMs. Following exposure to O3, AM phagocytosis is reduced and the mice develop a fatal infection. The persistence of bacteria in the lungs of O3-exposed rats triggers a transient influx of PMNs whose appearance corresponds with elimination of the bacteria. Differences in antimicrobial defenses between various experimental species and humans need to be better understood in order to predict effects of air pollutants on susceptibility to infection in man.
More, Simon John; Cameron, A. R.; Strain, S.; et al.
As part of a broader control strategy within herds known to be infected with Mycobacterium avium ssp. paratuberculosis (MAP), individual animal testing is generally conducted to identify infected animals for action, usually culling. Opportunities are now available to quantitatively compare different testing strategies (combinations of tests) in known infected herds. This study evaluates the effectiveness, cost, and cost-effectiveness of different testing strategies to identify infected animal...
El-Nassery, Suzanne M F; Abou-El-Naga, Iman F; Allam, Sonia R; Shaat, Eman A; Mady, Rasha F M
Much effort has been made to control schistosomiasis infection in Egypt. However, enduring effects from such strategies have not yet been achieved. In this study, we sought to determine the genetic variability related to the interaction between Biomphalaria alexandrina snails and Schistosoma mansoni. Using RAPD-PCR with eight (10 mers) random primers, we were able to determine the polymorphic markers that differed between snails susceptible and resistant to Schistosoma mansoni infection using five primers out of the eight. Our results suggest that the RAPD-PCR technique is an efficient means by which to compare genomes and to detect genetic variations between schistosomiasis intermediate hosts. The RAPD technique with the above-noted primers can identify genomic markers that are specifically related to the Biomphalaria alexandrina/Schistosoma mansoni relationship in the absence of specific nucleotide sequence information. This approach could be used in epidemiologic surveys to investigate genetic diversity among Biomphalaria alexandrina snails. The ability to determine resistant markers in Biomphalaria alexandrina snails could potentially lead to further studies that use refractory snails as agents to control the spread of schistosomiasis.
Currier, Rebecca L.; Payne, Daniel C.; Staat, Mary A.; Selvarangan, Rangaraj; Shirley, S. Hannah; Halasa, Natasha; Boom, Julie A.; Englund, Janet A.; Szilagyi, Peter G.; Harrison, Christopher J.; Klein, Eileen J.; Weinberg, Geoffrey A.; Wikswo, Mary E.; Parashar, Umesh; Vinjé, Jan; Morrow, Ardythe L.
Background. Norovirus is a leading cause of acute gastroenteritis (AGE). Noroviruses bind to gut histo-blood group antigens (HBGAs), but only 70%–80% of individuals have a functional copy of the FUT2 (“secretor”) gene required for gut HBGA expression; these individuals are known as “secretors.” Susceptibility to some noroviruses depends on FUT2 secretor status, but the population impact of this association is not established. Methods. From December 2011 to November 2012, active AGE surveillance was performed at 6 geographically diverse pediatric sites in the United States. Case patients aged norovirus by real-time reverse transcription polymerase chain reaction. Norovirus genotype was then determined by sequencing. Results. Norovirus was detected in 302 of 1465 (21%) AGE cases and 52 of 826 (6%) healthy controls. Norovirus AGE cases were 2.8-fold more likely than norovirus-negative controls to be secretors (P norovirus, GII.4. Control children of Meso-American ancestry were more likely than children of European or African ancestry to be secretors (96% vs 74%; P norovirus infection and varies by ancestry. GII.4 norovirus exclusively infected secretors. These findings are important to norovirus vaccine trials and design of agents that may block norovirus-HBGA binding. PMID:25744498
Suzanne M. F. El-Nassery
Full Text Available Much effort has been made to control schistosomiasis infection in Egypt. However, enduring effects from such strategies have not yet been achieved. In this study, we sought to determine the genetic variability related to the interaction between Biomphalaria alexandrina snails and Schistosoma mansoni. Using RAPD-PCR with eight (10 mers random primers, we were able to determine the polymorphic markers that differed between snails susceptible and resistant to Schistosoma mansoni infection using five primers out of the eight. Our results suggest that the RAPD-PCR technique is an efficient means by which to compare genomes and to detect genetic variations between schistosomiasis intermediate hosts. The RAPD technique with the above-noted primers can identify genomic markers that are specifically related to the Biomphalaria alexandrina/Schistosoma mansoni relationship in the absence of specific nucleotide sequence information. This approach could be used in epidemiologic surveys to investigate genetic diversity among Biomphalaria alexandrina snails. The ability to determine resistant markers in Biomphalaria alexandrina snails could potentially lead to further studies that use refractory snails as agents to control the spread of schistosomiasis.
Pereira, J F S; Mendes, J B; De Jong, G; Maia, D; Teixeira, V N; Passerino, A S; Garza, J J; Sotomaior, C S
With the aim of validating the FAMACHA(©) as a method for phenotypic selection of sheep resistant/resilient to gastrointestinal nematodes, 27 Suffolk ewes with known FAMACHA(©) score histories were experimentally infected with 25,000 larvae of Haemonchus contortus. From the day of infection (day 0) to 60 days post-infection, at intervals of 7-15 days, ewes were evaluated for packed cell volume (PCV) and fecal egg counts (FEC). A statistically significant increase (pFAMACHA(©) scores from the 27 ewes showed that 58.33% of the ewes classified as RR and 46.67% of the S group had a history of only F1 and F2 scores. In the RR group, only one animal (8.33%) had an F4 score, occurring one time out of the 61 evaluations of this ewe. In contrast, 40.0% of S group ewes had F4 and/or F5 scores. During the period of FAMACHA(©) score history that was evaluated, 69.56% of the total number of anthelmintic treatments in the flock were administered to ewes from group S. Since ewes with F4 and/or F5 scores during the FAMACHA(©) score time period were classified as susceptible during the experimental infection (with the exception of one ewe), we conclude that the FAMACHA(©) score history is a useful tool for the selection of ewes that are resistant/resilient, as well as for the identification of susceptible animals that should be culled. Copyright © 2016 Elsevier B.V. All rights reserved.
Garedew, Legesse; Taddese, Ayele; Biru, Tigist; Nigatu, Seleshe; Kebede, Elias; Ejo, Mebrat; Fikru, Abraham; Birhanu, Tamiru
Background Listeriosis, mostly caused by Listeria monocytogenes species, has become a major concern to public health authorities due to its clinical severity and high mortality rate, particularly in high risk groups. Currently, there is limited information regarding the prevalence and antimicrobial susceptibility profiles of listeria species in ready-to-eat foods of animal origin in Gondar town, Ethiopia. The aim of this study was to determine the prevalence and antimicrobial susceptibility p...
Full Text Available Efthimia Petinaki,1 Iris Spiliopoulou21Department of Microbiology, School of Medicine, University of Thessalia, Larissa, 2Department of Microbiology, School of Medicine, University of Patras, Patras, GreeceAbstract: Methicillin-resistant Staphylococcus aureus (MRSA remains one of the most virulent human pathogens and has also recently been recognized as such in the veterinary settings. Companion animals, including dogs, cats, horses, small exotic animals, wildlife animals, and livestock, may constitute a reservoir for MRSA transmission to humans and vice versa. The evolution, emergence, and risk factors for MRSA transmission among colonized or infected animals are reviewed in the present paper, and infection control practices are discussed.Keywords: methicillin-resistant Staphylococcus aureus, companion animals, close contacts
Hajiesmaeil, Mogge; Tafvizi, Farzaneh; Sarmadi, Soheila
Cervical cancer is the third most common cancer among women worldwide. Several factors lead to cervical cancer, among which human papilloma virus (HPV) infection has a prominent role. Methylenetetrahydrofolate reductase (MTHFR) is crucial in folate metabolic pathway and plays an important role in DNA synthesis and DNA methylation. MTHFR gene polymorphisms, including C677T and A1298C, lead to reduced enzyme activity. This case-control study aims to illustrate the association between MTHFR gene polymorphisms and the risk of cervical cancer. This study was conducted on 196 samples, which included 96 cervical biopsy samples compared to 100 Pap smear samples of normal healthy women without HPV infection. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used for the MTHFR polymorphism detection, followed by fluorescent amplification-based specific hybridization PCR method to detect HPV16 and HPV18. The results show that the MTHFR 677TT genotype plays a protective role in cervical cancer (P=0.0030) (OR=0.21, 95% confidence interval [CI]: 0.07-0.59). Furthermore, there was a strong significant association between MTHFR 1298CC genotype and the risk of cervical cancer (OR=10.69; 95% CI: 4.28-26.71, P=0.0001). It can be concluded that A1298C polymorphism is a genetic risk factor for cervical cancer in the assessed Iranian population group. It seems that MTHFR 1298CC genotype is more susceptible to HPV 16 infection. Combination analysis of MTHFR C677T and A1298C polymorphisms revealed that combined MTHFR 677CC and 1298CC are strongly associated with a risk of cervical cancer. Copyright Â© 2016 Elsevier B.V. All rights reserved.
Full Text Available Nervous necrosis virus (NNV is the causative agent of viral encephalopathy and retinopathy (VER, a neurological disease responsible for high mortality of fish species worldwide. Taking advantage of our established Chinese perch brain (CPB cell line derived from brain tissues of Mandarin fish (Siniperca chuatsi, the susceptibility of CPB cell to Red-Spotted Grouper nervous necrosis virus (RGNNV was evaluated. The results showed that RGNNV replicated well in CPB cells, resulting in cellular apoptosis. Moreover, the susceptibility of Mandarin fish to RGNNV was also evaluated. Abnormal swimming was observed in RGNNV-infected Mandarin fish. In addition, the cellular vacuolation and viral particles were also observed in brain tissues of RGNNV-infected Mandarin fish by Hematoxylin-eosin staining or electronic microscopy. The established RGNNV susceptible brain cell line from freshwater fish will pave a new way for the study of the pathogenicity and replication of NNV in the future.
Webber, R A; Rau, M E; Lewis, D J
The impact of interspecific behavioral differences on the relative susceptibility of third instar Aedes aegypti and Anopheles quadrimaculatus larvae to infection with cercariae of Plagiorchis noblei was determined. When permitted to move freely in a column of water, larvae of Ae. aegypti were significantly more susceptible to infection with the parasite than were An. quadrimaculatus larvae. This difference is ascribed to the significantly greater activity of Ae. aegypti larvae in the water column. Since cercariae are suspended in the column, particularly near the bottom, contact with larvae of Ae. aegypti may be enhanced, whereas contact with An. quadrimaculatus larvae, which tend to remain near the surface, may be reduced. Interspecific differences other than behavior are not thought to play a major role, since immobilized larvae of the two species did not differ significantly in their susceptibility to this parasite.
Full Text Available Aquatic vertebrates are very abundant in the world, and they are of tremendous importance in providing global food security and nutrition. However, emergent and resurgent viruses, such as ranavirus (e.g., Rana grylio virus, RGV and Andriasd avidianus ranavirus, ADRV, herpesvirus (e.g., Carassius carassius herpesvirus, CaHV, reovirus (e.g., grass carp reovirus 109, GCRV-109, Scophthal musmaximus reovirus, SMReV and Micropterus salmoides reovirus, MsReV, and rhabdovirus (e.g., Siniper cachuatsi rhabdovirus, SCRV and Scophthal musmaximus rhabdovirus, SMRV can cause severe diseases in aquaculture animals and wild lower vertebrates, such as frogs, giant salamanders, fish, and so on. Here, we will briefly describe the symptoms produced by the aforementioned viruses and the molecular basis of the virus–host interactions. This manuscript aims to provide an overview of viral diseases in lower vertebrates with an emphasis on visible symptomatic manifestations and pathogenesis.
Nielsen, Søren Saxmose; Toft, Nils; Gardner, Ian Andrew
Diagnostic test evaluations (DTEs) for chronic infections are challenging because a protracted incubation period has to be considered in the design of the DTE, and the adverse effects of infection may be widespread and progressive over an animal's entire life. Frequently, the specific purpose......) than originally intended. The objective of this paper is to outline a structured approach to the design and conduct of a DTE for diagnostic tests used for chronic infections in animals, and intended for different purposes. We describe the process from reflections about test purpose and the underlying...... of the test is not formally considered when a test is evaluated. Therefore, the result is often a DTE where test sensitivity and specificity estimates are biased, either because of problems with establishing the true infection status or because the test detects another aspect of the infection (and analyte...
Vijaya S. Rajmane
Full Text Available Background: The increased incidence of fungal infections in the past two decades has been overwhelming. Despite the fact that invasive fungal infections are still under-diagnosed and underreported, bloodstream infection due to Candida is now being recognized as an important public health problem especially in ICU patients with considerable morbidity, mortality and health care costs. Objective: To study the incidence, risk factors and antifungal susceptibility of Candida bloodstream infection in our hospital. Material and Methods: In the present study, the blood samples were collected from patients admitted in Surgical ICU. Samples were processed and antifungal susceptibility of the isolates was performed using standard protocol. Results: Out of total 93 patients, 14 (15.05% were positive for candidemia with equal distribution of both C. albicans and nonalbicans Candida spp. The risk factors associated with candidemia showing statistical significance were length of ICU stay > 7 days, mechanical ventilation, central venous catheters and uncontrolled diabetes. Among the patients with candidemia the mortality rate was 78.57 %. Resistance to Amphotericin B was seen in 33.33 % isolates of C. tropicalis and 100 % isolates of C. rugosa. 33.33 % of C. tropicalis and 50 % of C. rugosa showed dose dependent susceptibility to Fluconazole. Conclusion: Early diagnosis and antifungal susceptibility testing is very important in the treatment of candidemia for reducing the mortality rate.
Dicksved, Johan; Ellström, Patrik; Engstrand, Lars; Rautelin, Hilpi
The gut microbiota is essential for human health, but very little is known about how the composition of this ecosystem can influence and respond to bacterial infections. Here we address this by prospectively studying the gut microbiota composition before, during, and after natural Campylobacter infection in exposed poultry abattoir workers. The gut microbiota composition was analyzed with 16S amplicon sequencing of fecal samples from poultry abattoir workers during the peak season of Campylobacter infection in Sweden. The gut microbiota compositions were compared between individuals who became culture positive for Campylobacter and those who remained negative. Individuals who became Campylobacter positive had a significantly higher abundance of Bacteroides (P = 0.007) and Escherichia (P = 0.002) species than those who remained culture negative. Furthermore, this group had a significantly higher abundance of Phascolarctobacterium (P = 0.017) and Streptococcus (P = 0.034) sequences than the Campylobacter-negative group, which had an overrepresentation of Clostridiales (P = 0.017), unclassified Lachnospiraceae (P = 0.008), and Anaerovorax (P = 0.015) sequences. Intraindividual comparisons of the fecal microbiota compositions yielded small differences over time in Campylobacter-negative participants, but significant long-term changes were found in the Campylobacter-positive group (P microbiota reduces resistance to Campylobacter colonization in humans and that Campylobacter infection can have long-term effects on the composition of the human fecal microbiota. Studies using mouse models have made important contributions to our understanding of the role of the gut microbiota in resistance to bacterial enteropathogen colonization. The relative abundances of Escherichia coli and Bacteroides species have been pointed out as important determinants of susceptibility to Gram-negative pathogens in general and Campylobacter infection in particular. In this study, we assessed the
He, Yuqing; Zhang, Hehong; Sun, Zongtao; Li, Junmin; Hong, Gaojie; Zhu, Qisong; Zhou, Xuebiao; MacFarlane, Stuart; Yan, Fei; Chen, Jianping
Plant hormones play a vital role in plant immune responses. However, in contrast to the relative wealth of information on hormone-mediated immunity in dicot plants, little information is available on monocot-virus defense systems. We used a high-throughput-sequencing approach to compare the global gene expression of Rice black-streaked dwarf virus (RBSDV)-infected rice plants with that of healthy plants. Exogenous hormone applications and transgenic rice were used to test RBSDV infectivity and pathogenicity. Our results revealed that the jasmonic acid (JA) pathway was induced while the brassinosteroid (BR) pathway was suppressed in infected plants. Foliar application of methyl jasmonate (MeJA) or brassinazole (BRZ) resulted in a significant reduction in RBSDV incidence, while epibrassinolide (BL) treatment increased RBSDV infection. Infection studies using coi1-13 and Go mutants demonstrated JA-mediated resistance and BR-mediated susceptibility to RBSDV infection. A mixture of MeJA and BL treatment resulted in a significant reduction in RBSDV infection compared with a single BL treatment. MeJA application efficiently suppressed the expression of BR pathway genes, and this inhibition depended on the JA coreceptor OsCOI1. Collectively, our results reveal that JA-mediated defense can suppress the BR-mediated susceptibility to RBSDV infection. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.
Full Text Available Babesiosis caused by Babesia microti parasite is an emerging tick borne zoonotic disease that was confirmed recently in China. To understand the epidemiology characteristics of this emerging disease, infectivity of B. microti to domestic animals and ticks outside the genus Ixodes was evaluated in this study. Different domestic animals, chick, pig, goat, dog and the reference host rat were experimentally inoculated with B. microti-infected erythrocytes and the parasite infection was monitored daily by blood smear observation, real-time PCR detection, nested-PCR and special antibody responses during 55 days period. The results showed that rats infected with B. microti showed a typical sustained infection with strongly antibody responses; however, both goats and dogs infected with B. microti only showed transient antibody responses and the parasite was not found by blood smear observation or PCR; neither the parasite nor the special antibodies were detected in experimental chicks and pigs. On the other hand, the present study also experimentally investigated the infectivity of B. microti to Rhipicephalus haemaphysaloides, Haemaphysalis longicornis, and Hyalomma asiaticum three species of ticks outside the genus Ixodes and the transmission experiment of B. microti between H. longicornis ticks and mice. Results showed that B. microti can be detected in the nymph and adult of these species after molting from engorged tick fed on infected mice, but the parasite was not detected in larvae hatching from eggs of engorged female tick fed on the infected mice. Transmission of B. microti to mice by infected H. longicornis nymphs was confirmed. These results indicated that these domestic animals do not have reservoir competence for B. microti, however, three species of ticks out of the genus Ixodes, common in China were successfully infected by B. microti, with H. longicornis showing the potential of transmitting the parasite to the vertebrate host.
Sav, H.; Ozdemir, H.G.; Altinbas, R.; Kiraz, N.; Ilkit, M.; Seyedmousavi, S.
Investigations of both virulence factors and antifungal susceptibility profiles are crucial for understanding the pathogenesis and prognosis of ophthalmic mycoses. In this study, we investigated the in vitro antifungal susceptibility of amphotericin B (AMB), voriconazole (VRC), and natamycin (NAT)
Zhou, J; Smith, D K; Lu, L; Poon, V K M; Ng, F; Chen, D-Q; Huang, J-D; Yuen, K-Y; Cao, K-Y; Zheng, B-J
The type I interferon (IFN-alpha/beta) receptor 1 (IFNAR1) mediates the potent antiviral and immuno-regulatory effects of IFN-alpha/beta that are believed to be pivotal to eradicate hepatitis B virus (HBV) infection. IFNAR1 promoter polymorphisms (at -568/-77) have been shown to be associated with susceptibility to chronic HBV infection; however, whether these markers are genetic determinants of HBV infection remains unknown. The functional significance of promoter -568/-77 polymorphisms was assessed by mutagenesis and luciferase assays. Sequencing and restriction fragment length polymorphisms in 328 chronic HBV patients, 130 spontaneous resolvers and 148 healthy blood donors identified other polymorphism at IFNAR1 open reading frame. IFNAR1 expression levels in peripheral blood cells were detected by flow cytometry. We found that the -568/-77 promoter variants were unlikely to affect transcription levels. A C/G single nucleotide polymorphism, in strong linkage disequilibrium with the promoter polymorphisms, was found in the coding sequence of IFNAR1 (nt19158). This resulted in a nonsynonymous substitution in the extracellular region of IFNAR1 protein and correlated with susceptibility to chronic HBV infection. Bioinformatic analysis suggested decreased stability of the IFNAR1 protein. Chronic HBV patients with the 19158C/C genotype (Leu141) exhibited higher IFNAR1 protein expression levels in peripheral blood monocytes than those with the 19158G/G genotype (Val141). In conclusion, IFNAR1 19158C/G polymorphism is primarily associated with susceptibility to chronic HBV infection.
van der Geest, Patrick J; Rijnders, Bart J A; Vonk, Alieke G; Groeneveld, A B Johan
Invasive Candida spp. infections are increasingly diagnosed in critically ill patients. For initial treatment, an echinocandin is recommended with a possible step-down to fluconazole when the patients' condition is improving and the isolate appears susceptible, but there are no data to support such policy. We studied the safety and efficacy of step-down therapy in critically ill patients with culture proven deep seated or bloodstream infections by C. albicans susceptible to fluconazole. All patients admitted into the intensive care unit from January 2010 to December 2014, who had a culture proven invasive C. albicans infection and received initial treatment with an echinocandin for at least 4 days were included. Data on patient characteristics, treatment and vital outcomes were assessed. Of the 56 patients, 32 received step-down fluconazole therapy, at median day 5, whereas the echinocandin was continued in the other 24. No differences where seen in baseline characteristics or risk factors for invasive C. albicans infection between the two groups. Response rates were similar and no difference where seen in 28-day or 90-day mortality between the groups. Step-down therapy to fluconazole may be safe and effective in critically ill patients with invasive infections by C. albicans, susceptible to fluconazole, who have clinically improved as early as 4 days after start of treatment with an echinocandin. © 2015 Blackwell Verlag GmbH.
Laura A Brannelly
Full Text Available Amphibians worldwide are experiencing devastating declines, some of which are due to the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd. Populations in the southeastern United States, however, have not been noticeably affected by the pathogen. The green treefrog (Hyla cinerea is abundant and widespread in the southeastern United States, but has not been documented to harbor Bd infection. This study examined the susceptibility of H. cinerea to two strains of Bd in the lab and the prevalence of infection in wild populations of this species in southeastern Louisiana. Although we were able to infect H. cinerea with Bd in the lab, we did not observe any clinical signs of chytridiomycosis. Furthermore, infection by Bd does not appear to negatively affect body condition or growth rate of post-metamorphic individuals. We found no evidence of infection in surveys of wild H. cinerea. Our results suggest that H. cinerea is not susceptible to chytridiomycosis post-metamorphosis and probably is not an important carrier of the fungal pathogen Bd in the southeastern United States, although susceptibility at the larval stage remains unknown.
Sunday Ositadinma Udegbunam
Full Text Available Staphylococcal ocular infections of food animals have been somewhat under diagnosed probably due to the ubiquitous nature of staphylococcal organisms. This study was undertaken to determine the occurrence of staphylococcal ocular infections of food producing animals in Nsukka Southeast, Nigeria, and to determine the antibiogram of the isolated staphylococci. A total of 5,635 food producing animals were externally examined for signs of clinical ocular conditions. Animals that showed clinical eye lesions were further examined using pen light to assess the entire globe and the pupillary reflex. Blindness was assessed using menace blink reflex, palpebral reflex and obstacle methods. Isolation and identification of staphylococcal isolates from ocular swabs were done by standard methods. Antibiogram of the isolates was determined by disc diffusion method. Sixty-three (1.1% of the examined animals showed signs of ocular condition. Thirty-one (49.2% of the cultured swabs yielded Staphylococcus aureus (S. aureus. Isolation rates from different animal species were caprine (60%, ovine (33.3%, bovine (12.5%, and porcine (0%. Resistance of the isolates was 100% to ampicillin/cloxacillin, 90% to tetracycline, 80% to streptomycin, 71% to chloramphenicol, 20% to erythromycin, 16% to gentamicin, and 0% to ciprofloxacin and norfloxacin. Twenty-five (81% of the isolates were multi-drug resistant. This study has shown that antibiotic-resistant staphylococci are associated with a sizeable percentage of ocular infections of food producing animals and should be considered during diagnosis and treatment.
Bruun, Morten Sichlau; Madsen, Lone; Dalsgaard, Inger
The medication effect of oxytetracycline on groups of rainbow trout fry experimentally infected with three strains of Flavobacterium psychrophilum was investigated. The infection model was based on intraperitoneal injection of the pathogen and treatment was done using medicated feed resulting...... in 100 mg oxytetracycline/kg fish for 10 days. The three F. psychrophilum strains had different antimicrobial susceptibilities and successful treatment was only obtained in the trial using a strain with a MICOTC of 0.25 mug/ml. No effect of treatment was seen in the group infected with a strain having...... MICOTC of 8.0 mug/ml and only little effect was seen when the strain MICOTC was 4.0 mug/ml. This shows that it is valid to predict the treatment efficiency of OTC from in vitro data facing an outbreak of rainbow trout fry syndrome. The importance of doing susceptibility testing is emphasized...
Martinez, Nuria; Ketheesan, Natkunam; Martens, Gregory W; West, Kim; Lien, Egil; Kornfeld, Hardy
Diabetes is associated with increased susceptibility to Klebsiella pneumoniae and poor prognosis with infection. We demonstrate accelerated mortality in mice with streptozotocin-induced diabetes following tracheal instillation of K. pneumoniae. Diabetic mice recruited fewer granulocytes to the alveolar airspace and had reduced early production of CXCL1, CXCL2, IL-1β and TNF-α following tracheal instillation of K. pneumoniae-lipopolysaccharide. Additionally, TLR2 and TIRAP expression following K. pneumoniae-lipopolysaccharide exposure was decreased in hyperglycemic mice. These findings indicate that impaired innate sensing and failure to rapidly recruit granulocytes to the site of infection is a mechanism for diabetic susceptibility to respiratory K. pneumoniae infection. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.
Mangale, Vrushali; Marro, Brett S; Plaisted, Warren C; Walsh, Craig M; Lane, Thomas E
The present study examines the susceptibility of mouse induced pluripotent stem cell-derived neural precursor cells (iPSC-NPCs) to infection with the neurotropic JHM strain of mouse hepatitis virus (JHMV). Similar to NPCs derived from striatum of day 1 postnatal GFP-transgenic mice (GFP-NPCs), iPSC-derived NPCs (iPSC-NPCs) are able to differentiate into terminal neural cell types and express MHC class I and II in response to IFN-γ treatment. However, in contrast to postnatally-derived NPCs, iPSC-NPCs express low levels of carcinoembryonic antigen-cell adhesion molecule 1a (CEACAM1a), the surface receptor for JHMV, and are less susceptible to infection and virus-induced cytopathic effects. The relevance of this in terms of therapeutic application of NPCs resistant to viral infection is discussed. Copyright © 2017 Elsevier Inc. All rights reserved.
Sylvio Celso Gonçalves da Costa
Full Text Available Congenitally athymic nude Balb/c (nu/nu and their phenothypically normal adult and neonate littermates (nu/+, the C3H/HeN as well, were intraperitoneally infected with two strains (Y or CL of Trypanossoma cruzi. The nude mice and the neonates developed a severe parasitaemia, the susceptible C3H/HeN also presented high level and adult Balb/c mice presented parasitaemia similar to that observed in outbred mice. Erythematous skin lesions were observed initially in infected athymic nude and neonates, being charactherized by nests of amastigotes in the dermis; in C3H/HeN infected mice no nest of parasite was observed but a low-grade inflammatory reaction was seen. In adult Balb/c or OF1 outbred mice nest was found but discreet inflammatory reaction was observed in severe infections.
Ana Paula M. S. Brandão
Full Text Available Brucella abortus is a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. IFN-γ, IL-12, and CD8+ T lymphocytes are important components of host immune responses against B. abortus. Herein, IFN-γ and IL-12/β2-microglobulin (β2-m knockout mice were used to determine whether CD8+ T cells and IL-12-dependent IFN-γ deficiency would be more critical to control B. abortus infection compared to the lack of endogenous IFN-γ. At 1 week after infection, IFN-γ KO and IL-12/β2-m KO mice showed increased numbers of bacterial load in spleens; however, at 3 weeks postinfection (p.i., only IFN-γ KO succumbed to Brucella. All IFN-γ KO had died at 16 days p.i. whereas death within the IL-12/β2-m KO group was delayed and occurred at 32 days until 47 days postinfection. Susceptibility of IL-12/β2-m KO animals to Brucella was associated to undetectable levels of IFN-γ in mouse splenocytes and inability of these cells to lyse Brucella-infected macrophages. However, the lack of endogenous IFN-γ was found to be more important to control brucellosis than CD8+ T cells and IL-12-dependent IFN-γ deficiencies.
Heegaard, Peter M. H.; Hald, Birthe; Madsen, M.
. To control enteric infections by passive immunization a bolus of immunoglobulin may simply be administered orally. For this to work, large amounts of active immunoglobulins are needed. To be a real alternative to antibiotics the price of the immunoglobulin product needs to be low. We combined an efficient......Enteric infections cause major problems in most intensive animal production sectors, including poultry, pigs and cattle, leading to disease, reduced production and compromised welfare. In addition some of these infections are zoonotic, and they are to a large extent responsible for the continued...... massive use of antibiotics in food animals. Thus there is a pressing need for economically feasible, efficient, non-antibiotics based means for controlling the problem. Passive immunization has been known for decades as an efficient way of endowing humans or animals with short-term (weeks) immunity...
Spengler, Jessica R.; Estrada-Peña, Agustín; Garrison, Aura R.; Schmaljohn, Connie; Spiropoulou, Christina F.; Bergeron, Éric; Bente, Dennis A.
This article provides a definitive review of experimental studies of the role of wild animals and livestock in the maintenance and transmission of Crimean-Congo hemorrhagic fever virus (CCHFV), the etiologic agent of Crimean-Congo hemorrhagic fever (CCHF), beginning with the first recognized outbreak of the human disease in Crimea in 1944. Published reports by researchers in the former Soviet Union, Bulgaria, South Africa, and other countries where CCHF has been observed show that CCHFV is maintained in nature in a tick-vertebrate-tick enzootic cycle. Human disease most commonly results from the bite of an infected tick, but may also follow crushing of infected ticks or exposure to the blood and tissues of infected animals during slaughter. Wild and domestic animals are susceptible to infection with CCHFV, but do not develop clinical illness. Vertebrates are important in CCHF epidemiology, as they provide blood meals to support tick populations, transport ticks across wide geographic areas, and transmit CCHFV to ticks and humans during the period of viremia. Many aspects of vertebrate involvement in the maintenance and spread of CCHFV are still poorly understood. Experimental investigations in wild animals and livestock provide important data to aid our understanding of CCHFV ecology. This article is the second in a series of reviews of more than 70 years of research on CCHF, summarizing important findings, identifying gaps in knowledge, and suggesting directions for future research. PMID:27713073
Rowena Y Kelley
Full Text Available BACKGROUND: Aspergillus flavus infection and aflatoxin contamination of maize pose negative impacts in agriculture and health. Commercial maize hybrids are generally susceptible to this fungus. Significant levels of host plant resistance have been observed in certain maize inbred lines. This study was conducted to identify maize genes associated with host plant resistance or susceptibility to A. flavus infection and aflatoxin accumulation. RESULTS: Genome wide gene expression levels with or without A. flavus inoculation were compared in two resistant maize inbred lines (Mp313E and Mp04:86 in contrast to two susceptible maize inbred lines (Va35 and B73 by microarray analysis. Principal component analysis (PCA was used to find genes contributing to the larger variances associated with the resistant or susceptible maize inbred lines. The significance levels of gene expression were determined by using SAS and LIMMA programs. Fifty candidate genes were selected and further investigated by quantitative RT-PCR (qRT-PCR in a time-course study on Mp313E and Va35. Sixteen of the candidate genes were found to be highly expressed in Mp313E and fifteen in Va35. Out of the 31 highly expressed genes, eight were mapped to seven previously identified quantitative trait locus (QTL regions. A gene encoding glycine-rich RNA binding protein 2 was found to be associated with the host hypersensitivity and susceptibility in Va35. A nuclear pore complex protein YUP85-like gene was found to be involved in the host resistance in Mp313E. CONCLUSION: Maize genes associated with host plant resistance or susceptibility were identified by a combination of microarray analysis, qRT-PCR analysis, and QTL mapping methods. Our findings suggest that multiple mechanisms are involved in maize host plant defense systems in response to Aspergillus flavus infection and aflatoxin accumulation. These findings will be important in identification of DNA markers for breeding maize lines
Full Text Available Toxoplasma gondii is a zoonotic protozoan parasite that infects a wide range of warm-blooded animals throughout the world. In the present study, antibodies to T. gondii were determined using a commercial indirect hemagglutination (IHA test in wild animals in a zoo. Three of 11 giraffes (Giraffa camelopardalis (27%, 1 of 5 wolves (Canis lupus laniger (20%, 1 of 6 hippopotamuses (Hippopotamus amphibious (17%, and 2 of 9 tundra swans (Cygnus columbianus (22% were found to be positive. No antibodies were detected in leopards (Panthera pardus, wild geese (Anser cygnoides, and Eastern grey kangaroos (Macropus giganteus. Domestic species from 13 counties of Jiangxi Province, China were also investigated by an indirect hemagglutination (IHA test. Thirty-five of 340 goats (10%, 94 of 560 water buffaloes (17%, and 4 of 35 cattle (11% were found to be seropositive. This is the first report of T. gondii infection in animals kept in zoos and domestic animals in this province.
Saeedian, M.; Khalighi, M.; Azimi-Tafreshi, N.; Jafari, G. R.; Ausloos, M.
Memory has a great impact on the evolution of every process related to human societies. Among them, the evolution of an epidemic is directly related to the individuals' experiences. Indeed, any real epidemic process is clearly sustained by a non-Markovian dynamics: memory effects play an essential role in the spreading of diseases. Including memory effects in the susceptible-infected-recovered (SIR) epidemic model seems very appropriate for such an investigation. Thus, the memory prone SIR model dynamics is investigated using fractional derivatives. The decay of long-range memory, taken as a power-law function, is directly controlled by the order of the fractional derivatives in the corresponding nonlinear fractional differential evolution equations. Here we assume "fully mixed" approximation and show that the epidemic threshold is shifted to higher values than those for the memoryless system, depending on this memory "length" decay exponent. We also consider the SIR model on structured networks and study the effect of topology on threshold points in a non-Markovian dynamics. Furthermore, the lack of access to the precise information about the initial conditions or the past events plays a very relevant role in the correct estimation or prediction of the epidemic evolution. Such a "constraint" is analyzed and discussed.
Full Text Available The human beta defensin 1 (hBD-1 antimicrobial peptide is a member of the innate immune system known to act in the first line of defence against microorganisms, including viruses such as human papillomavirus (HPV. In this study, five functional polymorphisms (namely g-52G>A, g-44C>G and g-20G>A in the 5’UTR and c.*5G>A and c.*87A>G in the 3’UTR in the DEFB1 gene encoding for hBD-1 were analysed to investigate the possible involvement of these genetic variants in susceptibility to HPV infection and in the development of HPV-associated lesions in a population of Brazilian women. The DEFB1 g-52G>A and c.*5G>A single-nucleotide polymorphisms (SNPs and the GCAAA haplotype showed associations with HPV-negative status; in particular, the c.*5G>A SNP was significantly associated after multiple test corrections. These findings suggest a possible role for the constitutively expressed beta defensin-1 peptide as a natural defence against HPV in the genital tract mucosa.
Premasiri, W R; Chen, Ying; Williamson, P M; Bandarage, D C; Pyles, C; Ziegler, L D
SERS spectra of 12 bacterial strains of urinary tract infection (UTI) clinical isolates grown and enriched from urine are reported. A partial least squares-discriminant analysis (PLS-DA) classification treatment of these SERS spectra results in strain level identification with >95% sensitivity and >99% specificity. The classification model successfully identified the SERS spectra of a urine-cultured strain not used to build this statistical model. Enrichment was accomplished by a filtration and centrifugation protocol. The predetermined drug susceptibility profiles of these clinical isolates thus allowed the SERS methodology to provide appropriate UTI antibiotic information in less than 1 h. Most of this time was used for sample preparation procedures (enrichment and washing) for this proof of principle study. SERS spectra of the enriched bacterial samples are dominated by nucleotide degradation metabolites: adenine, hypoxanthine, xanthine, guanine, uric acid, AMP, and guanosine. Strain-specific specificity is due to the different relative amounts of these purines contributing to the corresponding SERS spectra of these clinical isolates. All measurements were made at the minimal bacterial concentration in urine for UTI diagnosis (105 cfu/mL). Graphical abstract The relative contribution of each of the seven purines found to contribute to the bacterial SERS spectra are summarized in this bar graph. Although strain specific differences are evident, it can be see how the pattern of contributing purines is more different between the four species than between strains of a given species.
Arent, Z J; Gilmore, C; San-Miguel Ayanz, J M; Neyra, L Quevedo; García-Peña, F J
Strains of Leptospira serogroup Pomona are known to cause widespread animal infections in many parts of the world. Forty-three isolates retrieved from domestic animals and wild small mammals suggest that serogroup Pomona is epidemiologically relevant in Spain. This is supported by the high prevalence of serovar Pomona antibodies in livestock and wild animals. In this study, the strains were serologically and genetically characterized in an attempt to elucidate their epidemiology. Serological typing was based on the microscopic agglutination test but molecular typing involved species-specific polymerase chain reaction, restriction endonuclease analysis, and multiple-locus variable-number tandem repeat analysis. The study revealed that the infections are caused by two serovars, namely Pomona and Mozdok. Serovar Pomona was derived only from farm animals and may be adapted to pigs, which are recognized as the maintenance host. The results demonstrated that serovar Pomona is genetically heterogeneous and three different types were recognized. This heterogeneity was correlated with different geographical distributions of the isolates. All strains derived from small wild mammals were identified as serovar Mozdok. Some isolates of this serovar retrieved from cattle confirm that this serovar may also be the cause of infections in food-producing animals for which these wild species may be source of infection.
Moy, Terence I.; Conery, Annie L.; Larkins-Ford, Jonah; Wu, Gang; Mazitschek, Ralph; Casadei, Gabriele; Lewis, Kim; Carpenter, Anne E.; Ausubel, Frederick M.
The nematode Caenorhabditis elegans is a unique whole animal model system for identifying small molecules with in vivo anti-infective properties. C. elegans can be infected with a broad range of human pathogens, including Enterococcus faecalis, an important human nosocomial pathogen with a mortality rate of up to 37% that is increasingly acquiring resistance to antibiotics. Here, we describe an automated, high throughput screen of 37,200 compounds and natural product extracts for those that enhance survival of C. elegans infected with E. faecalis. The screen uses a robot to accurately dispense live, infected animals into 384-well plates, and automated microscopy and image analysis to generate quantitative, high content data. We identified 28 compounds and extracts that were not previously reported to have antimicrobial properties, including 6 structural classes that cure infected C. elegans animals but do not affect the growth of the pathogen in vitro, thus acting by a mechanism of action distinct from antibiotics currently in clinical use. Our versatile and robust screening system can be easily adapted for other whole animal assays to probe a broad range of biological processes. PMID:19572548
Full Text Available Uncomplicated urinary tract infections (UTI in women are very common. Regular analysis of bacterial flora is important to formulate updated guidelines. The objective of this study is to determine and compare the microbiology of UTIs and their susceptibility patterns in a quaternary care hospital. In a seven-year review, the urine culture results of 480 female patients with uncomplicated UTIs were analyzed. Patients were divided into three groups according to their diagnosis and treatment characteristics: Group 1, cystitis at outpatient basis; group 2, cystitis at the Emergency Unit; and group 3, pyelonephritis. Group 1 included older patients, with a higher incidence of concomitant diabetes mellitus and recurrent UTIs. E. coli was the most common pathogen, responsible for 75.1% of cases, mainly for pyelonephritis (87.3%. Of the oral antimicrobials tested for cystitis, amoxicillin/clavulanate and nitrofurantoin had the highest susceptibility profiles (84.4% and 87.3%, respectively. For E. coli only, their susceptibility profiles were as high as 90.8% and 97.4%, respectively. For pyelonephritis treatment, fluoroquinoles had a susceptibility profile <90%, while ceftriaxone and gentamicin had susceptibility >90%. Uncomplicated UTI treatment is becoming more challenging because the susceptibility profiles of oral antimicrobials are increasingly resistant. In our environment, cystitis can still be managed with nitrofurantoin. Uncomplicated pyelonephritis should be managed with ceftriaxone or gentamicin.
Silva, Andrea Alice; Silva, Rafael Rodrigues; Gibaldi, Daniel; Mariante, Rafael Meyer; Dos Santos, Jessica Brandão; Pereira, Isabela Resende; Moreira, Otacílio Cruz; Lannes-Vieira, Joseli
In conditions of immunosuppression, the central nervous sty 5ystem (CNS) is the main target tissue for the reactivation of infection by Trypanosoma cruzi, the causative agent of Chagas disease. In experimental T. cruzi infection, interferon gamma (IFNγ) + microglial cells surround astrocytes harboring amastigote parasites. In vitro, IFNγ fuels astrocyte infection by T. cruzi, and IFNγ-stimulated infected astrocytes are implicated as potential sources of tumor necrosis factor (TNF). Pro-inflammatory cytokines trigger behavioral alterations. In T. cruzi-infected mice, administration of anti-TNF antibody hampers depressive-like behavior. Herein, we investigated the effects of TNF on astrocyte susceptibility to T. cruzi infection and the regulation of cytokine production. Primary astrocyte cultures of neonatal C57BL/6 and C3H/He mice and the human U-87 MG astrocyte lineage were infected with the Colombian T. cruzi strain. Cytokine production, particularly TNF, and TNF receptor 1 (TNFR1/p55) expression were analyzed. Recombinant cytokines (rIFNγ and rTNF), the anti-TNF antibody infliximab, and the TNFR1 modulator pentoxifylline were used to assess the in vitro effects of TNF on astrocyte susceptibility to T. cruzi infection. To investigate the role of TNF on CNS colonization by T. cruzi, infected mice were submitted to anti-TNF therapy. rTNF priming of mouse and human astrocytes enhanced parasite/astrocyte interaction (i.e., the percentage of astrocytes invaded by trypomastigote parasites and the number of intracellular parasite forms/astrocyte). Furthermore, T. cruzi infection drove astrocytes to a pro-inflammatory profile with TNF and interleukin-6 production, which was amplified by rTNF treatment. Adding rTNF prior to infection fueled parasite growth and trypomastigote egression, in parallel with increased TNFR1 expression. Importantly, pentoxifylline inhibited the TNF-induced increase in astrocyte susceptibility to T. cruzi invasion. In T. cruzi-infected mice
Delgado Márcio Oliveira
Full Text Available Mycoplasma pulmonis have been isolated in about 10(5 CFU/mL from tracheal aspirates of rats from conventional animal facilities in São Paulo. The mycoplasma transmission by aerosol may happen from an infected rat to a healthy one at distances up to 120 cm. This condition also favors the technicians contamination. As this infection is unknown in humans, in this study the immunoblot profiles to M. pulmonis of sera from rats were compared to those presented by animal facility technicians. About 32 proteins from 11 to 230 kDa (kilodaltons were recognized by the sera from rats naturally infected with M. pulmonis. Sera from technicians responsible for the cleaning and sanitation of cages of infected animals for more than seven years recognized about 10 proteins of this bacteria. Sera from individuals with shorter working time or that had never been exposed to such environment recognized few proteins. Proteins about 117 and 95 kDa were recognized by human and rat sera and by the negative controls. Although a positive human serum against M. pulmonis is unknown, this study established a temporary profile of protein recognition of human serum against such mycoplasma.
Temmam, Sarah; Davoust, Bernard; Berenger, Jean-Michel; Raoult, Didier; Desnues, Christelle
Many human viral infections have a zoonotic, i.e., wild or domestic animal, origin. Several zoonotic viruses are transmitted to humans directly via contact with an animal or indirectly via exposure to the urine or feces of infected animals or the bite of a bloodsucking arthropod. If a virus is able to adapt and replicate in its new human host, human-to-human transmissions may occur, possibly resulting in an epidemic, such as the A/H1N1 flu pandemic in 2009. Thus, predicting emerging zoonotic infections is an important challenge for public health officials in the coming decades. The recent development of viral metagenomics, i.e., the characterization of the complete viral diversity isolated from an organism or an environment using high-throughput sequencing technologies, is promising for the surveillance of such diseases and can be accomplished by analyzing the viromes of selected animals and arthropods that are closely in contact with humans. In this review, we summarize our current knowledge of viral diversity within such animals (in particular blood-feeding arthropods, wildlife and domestic animals) using metagenomics and present its possible future application for the surveillance of zoonotic and arboviral diseases. PMID:24918293
Parmênedes Dias de Brito
Full Text Available Trypanosoma vivax is a protozoan originating from the African continent, which, although it has not yet been able to complete its biological cycle in South America, due to the absence of the tsetse fly, can still cause death in ruminants. The objective of this study was to verify the effects of T. vivax on the measurements and indices in sheep that characterize animal performance, as well as on economic losses in meat animals. Twenty intact adult male sheep were used for this study, all of approximately the same ages and weights, reared in confinement, and subjected to the same management and diet, which was balanced and supplemented with adequate minerals. The animals were divided into two groups: the control group (CG and the infected group (IG, which was inoculated intravenously with 1.3 x 105 trypomastigotes of T. vivax. Feed intake was verified daily, whereas the feed conversion (FC, feed efficiency index (FEI, and weight gain were obtained weekly. Total weight gain (TWG was determined after 70 days post-infection. The economic loss was calculated by subtracting the value obtained (IG from the expected value (CG, and the difference was expressed as a percentage. A randomized block design was used to isolate the effect of the initial weight. The means were compared by the Student “t” test at 5%. Of the 10 infected animals, one died from the parasitism, yielding a rate much lower than that observed in natural outbreaks. The groups presented similar feed intakes throughout the experimental period; however, the TWG of the infected group was significantly lower (50.7% than that of the CG. Similarly, the daily weight gain (DWG, feed conversion (FC, and feed efficiency index (FEI of the IG were significantly lower than those of the CG. In addition, the worst rates of FC and FEI coincided with parasitemia peaks and recurrences, probably due to immunological demand and tissue repair. The abdominal circumference of the infected animals was
Talaat, Roba M; Abdelkhalek, Mohamed S; El-Maadawy, Eman A; Abdel-Mageed, Wael S; El-Shenawy, Soha Z; Osman, Mohamed A
Tumor necrosis factor alpha (TNF-α) is one of the important cytokine in generating an immune response against hepatitis B virus (HBV). Genetic polymorphisms might influence gene transcription, leading to disturbance in cytokine production. We hypothesized that single nucleotide polymorphism (SNPs) in TNF-α gene could affect the pathogenesis of HBV. To test this hypothesis, we investigated the role of TNF-α polymorphism [-863C/A (rs1800630), -308G/A (rs1800629), -376G/A (rs1800750), -857C/T (rs1799724) and +489G/A (rs1800610)] in the susceptibility to chronic hepatitis B (CHB) infection. Polymorphisms of the TNF-α (-863C/A (rs1800630), -308G/A) were analyzed by Polymerase chain reaction sequence specific primer (PCR-SSP) while TNF-α (-376G/A, -857C/T and +489G/A) by PCR-restriction fragment length polymorphism (PCR-RFLP) in 104 patients with CHB and 104 healthy controls. The plasma level of TNF-α was measured using Enzyme-linked immunosorbent assay (ELISA). The study showed a significant increase in the frequency of -863CC, -376GA, -857CC, -857TT and +489GA genotypes and -863C, -376A, -857C, and +489A alleles in CHB patients compared to controls. In addition, CAGCG haplotype had a highest frequency in CHB patients. A strong Linkage Disequilibrium (LD) between TNF-α -863C/A (rs1800630) and -376G/A (D' = 0.7888, r 2 = 0.0200); -308G/A and -857C/T (D' = 0.9213, r 2 = 0.1770); -308G/A and +489G/A (D' = 0.9088, r 2 = 0.1576) was demonstrated. CHB patients had significantly lower levels of TNF-α compared to controls. In conclusion, our preliminary results suggest that -863C/A (rs1800630), -308G/A, -376G/A, and +489G/A of the TNF-α gene may play a role in HBV susceptibility in Egyptians. The significant reduction in TNF-α in CHB patient was independent of any particular genotype/haplotype in TNF-α. Copyright © 2017 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.
Vanrompay, Daisy; Hoang, Thi Q. T.; De Vos, Liselotte; Verminnen, Kristel; Harkinezhad, Taher; Chiers, Koen; Morré, Servaas A.; Cox, Eric
The purpose of the present study was to evaluate pigs as a large-animal model for female genital infection with two Chlamydia trachomatis human serovar E strains. Sixteen-week-old specific-pathogen-free female pigs (gilts) were intravaginally infected with the trachoma type E reference strain Bour or the urogenital serovar E strain 468. Several conclusions can be drawn from our findings on the pathogenicity of a primary C. trachomatis genital infection in gilts. First of all, we demonstrated ...
Linda L. Han
Full Text Available We analyzed signs occurring among domestic and wild terrestrial animal species infected with raccoon rabies variant virus (RRV in Massachusetts, 1992–2010. The clinical sign of aggression was significantly associated with rabid stray cats (odds ratio, OR = 2.3 and RRV affected major wild terrestrial animal species individually, which included raccoons (OR = 2.8, skunks (OR = 8.0, gray foxes (OR = 21.3, red foxes (OR = 10.4, woodchucks (OR = 4.7 and coyotes (OR = 27.6. While aggression is a useful predictor of rabies among wild animals, combinations of other signs such as ataxia, disorientation, and salivation are useful predictors of rabies among domestic animals. Pets reported with multiple clinical signs had significantly higher rabies positive testing result than those reported with single clinical sign (p < 0.001. The result suggested the importance of avoiding aggressive terrestrial wild animals and giving additional attention to pets with multiple clinical signs.
Knight, Matty; Elhelu, O; Smith, M; Haugen, B; Miller, A; Raghavan, N; Wellman, C; Cousin, C; Dixon, F; Mann, V; Rinaldi, G; Ittiprasert, W; Brindley, PJ
The freshwater snail, Biomphalaria glabrata is the obligate intermediate host for the transmission of the parasitic trematode, Schistosoma mansoni the causative agent of the chronic debilitating neglected tropical disease, schistosomiasis. We showed previously that in juvenile snails, early and significant induction of stress manifested by the expression of stress proteins, Hsp 70, Hsp 90 and reverse transcriptase (RT) of the non- LTR retrotransposon, nimbus, is a characteristic feature of juvenile susceptible NMRI but not resistant BS-90 snails. These latter, however, could be rendered susceptible after mild heat shock at 32°C, revealing that resistance in the BS-90 resistant snail to schistosomes is a temperature dependent trait. Here we tested the hypothesis that maintenance of BS-90 resistant snails at the permissive temperature for several generations affects the resistance phenotype displayed at the non-permissive temperature of 25°C. The progeny of BS-90 snails bred and maintained through several generations (F1 to F4) at 32°C were susceptible to the schistosome infection when returned to room temperature, shedding cercariae at four weeks post-infection. Moreover, the study of expression levels of the heat shock protein (Hsp) 70 protein by ELISA and western blot analysis, showed that this protein is also differentially expressed between susceptible and resistant snails, with susceptible snails expressing more protein than their resistant counterparts after early exposure to wild-type but not to radiation-attenuated miracidia. These data suggested that in the face of global warming, the ability to sustain a reduction in schistosomiasis by using refractory snails as a strategy to block transmission of the disease might prove challenging since non-lethal elevation in temperature, affects snail susceptibility to S. mansoni. PMID:26504668
Despite the worldwide importance of zoonotic parasite Toxoplasma gondii nothing is known of toxoplasmosis in animals in Angola. The present study aimed at estimating the seroprevalence and also assessing correlates of T. gondii infection in pet dogs from Luanda, Angola. Dogs (n = 103) brought to a v...
Domachowske, Joseph B; Bonville, Cynthia A; Rosenberg, Helene F
Human respiratory syncytial virus (hRSV) infection causes a spectrum of illnesses ranging from mild infection to life-threatening bronchiolitis and respiratory failure. Human studies on the pathogenesis of RSV infection are invaluable, but animal models permit advances with the use of experimental strategies that would be inappropriate in human studies. We review the advantages and disadvantages of various animal models for the study of hRSV infection. No animal model of hRSV infection replicates the complete spectrum of disease severity seen in humans. Available models differ in their ability to incorporate genetic technology and to allow the study of immunity, vaccine efficacy and treatment interventions. Although hRSV establishes disease in primates, this advantage is outweighed by the impracticalities and cost of using such models. The study of bovine RSV infection in calves is appealing because of parallels with human disease. Among rodent models, BALB/c mice have helped delineate the mechanisms underlying vaccine-enhanced RSV disease, and cotton rats have been used for preclinical testing. The single major disadvantage of studying hRSV in rodent models is the limited extent to which this host-restricted human pneumovirus replicates in mouse lung tissue. The rodent-specific Pneumovirus pathogen, pneumonia virus of mice, causes an infection that mirrors severe bronchiolitis and pneumonia in infants infected with RSV, including robust virus replication with profound inflammation. The recent development of the pneumonia virus of mice model has permitted exploration of the mechanisms of severe Pneumovirus disease in vivo with the use of sophisticated genetic tools and genetically manipulated mouse strains.
Alasaad, Samer; Permunian, Roberto; Gakuya, Francis; Mutinda, Matthew; Soriguer, Ramón C; Rossi, Luca
One of the main aims of forensic investigation is the detection and location of people and substances of interest, such as missing people and illegal drugs. Dogs (Canis lupus var. familiaris) have had an important role in legal and forensic investigations for decades; nonetheless canines' keen sense of smell has never been utilized in either the surveillance or control of wildlife diseases. The rapid removal and treatment of infected carcasses and/or sick animals is a key task in the management of infectious diseases, but it is usually difficult or impractical to carry out in the wild. In this paper we report on a study running over a period of 15 years, in which - for the first time to our knowledge - two disease-detector dogs were trained to follow the scent of Sarcoptes-infected animals and to find carcasses, even under the snow, and apparently no false positives were detected in fieldwork. Sarcoptic mange-detector dogs were used to collect the carcasses of 292 mangy wild animals and to identify, separate from their herd, and capture 63 mange-infected wild animals in the Italian Alps. Properly trained disease-detector dogs are an efficient and straightforward tool for surveillance and control of sarcoptic mange in affected wild animal populations.
Background One of the main aims of forensic investigation is the detection and location of people and substances of interest, such as missing people and illegal drugs. Dogs (Canis lupus var. familiaris) have had an important role in legal and forensic investigations for decades; nonetheless canines’ keen sense of smell has never been utilized in either the surveillance or control of wildlife diseases. The rapid removal and treatment of infected carcasses and/or sick animals is a key task in the management of infectious diseases, but it is usually difficult or impractical to carry out in the wild. Results In this paper we report on a study running over a period of 15 years, in which - for the first time to our knowledge - two disease-detector dogs were trained to follow the scent of Sarcoptes-infected animals and to find carcasses, even under the snow, and apparently no false positives were detected in fieldwork. Sarcoptic mange-detector dogs were used to collect the carcasses of 292 mangy wild animals and to identify, separate from their herd, and capture 63 mange-infected wild animals in the Italian Alps. Conclusions Properly trained disease-detector dogs are an efficient and straightforward tool for surveillance and control of sarcoptic mange in affected wild animal populations. PMID:22776804
Full Text Available Abstract Background One of the main aims of forensic investigation is the detection and location of people and substances of interest, such as missing people and illegal drugs. Dogs (Canis lupus var. familiaris have had an important role in legal and forensic investigations for decades; nonetheless canines’ keen sense of smell has never been utilized in either the surveillance or control of wildlife diseases. The rapid removal and treatment of infected carcasses and/or sick animals is a key task in the management of infectious diseases, but it is usually difficult or impractical to carry out in the wild. Results In this paper we report on a study running over a period of 15 years, in which - for the first time to our knowledge - two disease-detector dogs were trained to follow the scent of Sarcoptes-infected animals and to find carcasses, even under the snow, and apparently no false positives were detected in fieldwork. Sarcoptic mange-detector dogs were used to collect the carcasses of 292 mangy wild animals and to identify, separate from their herd, and capture 63 mange-infected wild animals in the Italian Alps. Conclusions Properly trained disease-detector dogs are an efficient and straightforward tool for surveillance and control of sarcoptic mange in affected wild animal populations.
Castro, Luz Ángela
Full Text Available Introduction: Candida albicans is the most frequently isolated yeast from the oral cavity of HIV-infected individuals. The use of fluconazole has increased the number of resistant or less-sensitive Candida species different from C. albicans, to this antifungal agent. Objective: To establish the Candida species present in the oral cavity of HIV-infected individuals at a hospital in Cali (Colombia, their population densities, and the susceptibility to fluconazole of species different from C. albicans. Materials and methods: Samples were cultured in CHROMagar Candida and the number of colony forming units (CFU was counted. Yeast identification was done with API 20C Aux, and the susceptibility tests to fluconazole, by Etest. Results: 230 patients were studied, and 202 isolates were obtained: 106 single and 96 mixed. C. albicans predominated, followed by C. dubliniensis and C. glabrata. Candida species other than C. albicans predominated in counts lower than 400 CFU/mL. Susceptibility study to fluconazole of species different from C. albicans showed that 14 (40 % of the isolates were susceptible dose-dependent and 7 (20 %, resistant. Conclusion: In the studied population, the oral cavity was colonized by non-wild type isolates that represent a risk for the development of oropharyngeal candidiasis resistant to fluconazole treatment.
Full Text Available Aim: We studied the causative microorganisms and antibiotic susceptibility of urinary tract infections (UTI for both male and female in Nagaland, North-Eastern India. Materials and Methods: This is a retrospective study done at Christian Institute of Health Sciences and Research, Dimapur, where urinary samples received for culture and sensitivity in the laboratory from January 2012 to June 2013 were included. Organisms were identified by doing standard culture method, and antibiotic sensitivity was done by Kirby-Bauer Disc diffusion method from mid-stream clean catch urine sample. Results: A total of 1789 samples were analyzed in this study, where 502 (28.1% showed significant growth, 330 (18.4% showed insignificant growth, and the rest 957 (53.5% showed no growth. The most commonly isolated bacterium was Escherichia coli both in an outpatient department (31% and in-patient department (38% patients followed by Klebsiella pneumonia, Pseudomonas sp., Enterococcus, Staphylococcus aureus, Candida, and Proteus. Analysis of the samples showed that UTI was more common in females (60% as compared to males (40%. It was also observed that the samples responded effectively to chloramphenicol (29%, gentamicin (28%, imipenem (26%, and amikacin (21%. High degree of resistance was shown for nalidixic acid, ciprofloxacin, norfloxacin, amoxyclav, and ofloxacin. Conclusion: Antibiotics have been in use for a long period and more often the misuse of antimicrobial drugs has today led to a general rise in the emergence of resistant bacteria. This study may aid health professionals in choosing the appropriate treatment for patients in North-Eastern India.
S. Mukaratirwa; I.F. Munjere; M. Takawira; G. Chingwena
Gastrodiscosis outbreaks due to Gastrodiscus aegyptiacus were recorded in horses in the vicinity of Harare, Zimbabwe, in the absence of Bulinus forskalii, B. senegalensis and Cleopatra sp. which are considered to be the only intermediate host snails. This suggested the possibility of other snail species acting as intermediate hosts in the life cycle of the trematode. A study was carried out to determine the susceptibility of 7 freshwater snail species to infection with G. aegyptiacus. First g...
Hepatitis C virus (HCV) causes liver-related death in more than 300,000 people annually. Treatments for patients with chronic HCV are suboptimal, despite the introduction of directly acting antiviral agents. There is no vaccine that prevents HCV infection. Relevant animal models are important...... for HCV research and development of drugs and vaccines. Chimpanzees are the best model for studies of HCV infection and related innate and adaptive host immune responses. They can be used in immunogenicity and efficacy studies of HCV vaccines. The only small animal models of robust HCV infection are T......- and B- cell deficient mice with human chimeric livers. Although these mice cannot be used in studies of adaptive immunity, they have provided new insights into HCV neutralization, interactions between virus and receptors, innate host responses, and therapeutic approaches. Recent progress in developing...
Cho, Soo Jung; Plataki, Maria; Mitzel, Dana; Lowry, Gena; Rooney, Kristen; Stout-Delgado, Heather
Post-viral pneumococcal pneumonia is a leading morbidity and mortality in older patients (≥65years of age). The goal of our current study is to understand the impact of chronological aging on innate immune responses to a secondary, post viral infection with Streptococcus pneumoniae, a causative agent of bacterial pneumonia. Using aged murine models of infection, our findings demonstrate increased morbidity and mortality in aged mice within 48h post-secondary S. pneumoniae infection. Increased susceptibility of aged mice was associated with decreased TLR1, TLR6, and TLR9 mRNA expression and diminished IL1β mRNA expression. Examination of NLRP3 inflammasome expression illustrated decreased NLRP3 mRNA expression and decreased IL1β production in aged lung in response to secondary S. pneumoniae infection. Copyright © 2017 Elsevier Inc. All rights reserved.
Tiawsirisup, Sonthaya; Platt, Kenneth B; Evans, Richard B; Rowley, Wayne A
The susceptibility of Ochlerotatus trivittatus (Coq.) to West Nile virus (WNV) was assessed by comparing it to the susceptibility of Aedes albopictus (Skuse), a likely bridge vector, and Culex pipiens (L.), a primary WNV amplifying species. The three species were infected with WNV (NY crow-1999) by feeding on 2-3-day-old chickens with serum virus titers ranging from 10(2.5) to 10(9.5) cell culture infective dose (CID) 50s/mL. The lowest infective titer for Oc. trivittatus and Cx. pipiens was 10(4.5) CID50s/mL. Thirteen percent (4/32) and 2% (1/45) of each species became infected postprandially. Infection rates of the two species increased to 43% (6/14) and 15% (6/40) after blood meals with a titer of 10(5.5) CID50s/mL. In contrast no infection was observed in nine Ae. albopictus that fed among three chickens with titers of 10(4.5) CID50s/mL nor in 41 Ae. albopictus that fed among three chickens with titers of 10(5.0) CID50s/mL. The infective dose 50s for Oc. trivittatus, Cx. pipiens and Ae. albopictus were 10(6.0), 10(6.2), and 10(6.6) CID50s/mL, respectively. Collectively these observations suggest that Oc. trivittatus and Cx. pipiens are more susceptible than Ae. albopictus to WNV when they feed on hosts with WNV titers of susceptible with blood meal titers of > or =10(7.5) CID50s/mL. Unpublished studies in our laboratory showed that cottontail rabbits fed on by WNV-infected Oc. trivittatus developed viremias as high as 10(5.5) CID50s/mL serum which exceeds 10 (4.2 (3.4-4.6)) CID50s/mL, the predicted ID10+/-95% CI of Oc. trivittatus. Consequently this mosquito, which also feeds on humans and birds has the potential to serve as a bridge vector and as a maintenance vector among mammals.
Karimi, O.; Ouburg, S.; de Vries, H. J. C.; Pena, A. S.; Pleijster, J.; Land, J. A.; Morre, S. A.
Chlamydia trachomatis infections may cause several disease conditions ranging from asympromatic infections to severe upper genital tract pathology, thereby causing significant morbidity worldwide. Remarkable interindividual differences in the clinical course of C. trachomatis infection have been
Guk, Sang-Mee; Park, Jin-Young; Seo, Min; Han, Eun-Taek; Kim, Jae-Lip; Chai, Jong-Yil
Susceptibility of inbred mouse strains to Metagonimus yokogawai, Metagonimus miyatai, and Metagonimus takahashii infections was studied using BALB/c, ddY, C57BL/6J, C3H/HeN, and A/J mice, with H-2 haplotypes d, s, b, k, and a, respectively. Two hundred metacercariae were orally fed to each mouse, and the worm recovery rates (WRR), worm dimensions, and intrauterine egg numbers were measured at days 3, 7, 14, 21, and 28 postinfection (PI). On day 14 PI, the WRR of M. yokogawai was highest in ddY mice (average, 62.2%); those of M. miyatai and M. takahashii were highest in ddY (19.5%) and BALB/c mice (10.4%), respectively; worm maturation was best in C3H/HeN (M. yokogawai), C57BL/6J (M. miyatai), and ddY mice (M. takahashii). All mouse strains showed higher susceptibility to infection with M. yokogawai than with M. miyatai or M. takahashii. The results show that susceptibility of mice to Metagonimus infection varies according to mouse strain and parasite species but is suggested to be independent of the mouse H-2 haplotype.
Full Text Available Lectins/carbohydrate binding can be involved in the Schistosoma mansoni recognition and activation of the Biomphalaria hemocytes. Therefore, expression of lectin ligands on Biomphalaria hemocytes would be associated with snail resistance against S. mansoni infection. To test this hypothesis, circulating hemocytes were isolated from B. glabrata BH (snail strain highy susceptible to S. mansoni, B. tenagophila Cabo Frio (moderate susceptibility, and B. tenagophila Taim (completely resistant strains, labelled with FITC conjugated lectins (ConA, PNA, SBA, and WGA and analyzed under fluorescence microscopy. The results demonstrated that although lectin-labelled hemocytes were detected in hemolymph of all snail species tested, circulating hemocytes from both strains of B. tenagophila showed a larger number of lectin-labelled cells than B. glabrata. Moreover, most of circulating hemocytes of B. tenagophila were intensively labelled by lectins PNA-FITC and WGA-FITC, while in B. glabrata small hemocytes were labeled mainly by ConA. Upon S. mansoni infection, lectin-labelled hemocytes almost disappeared from the hemolymph of Taim and accumulated in B. glabrata BH. The role of lectins/carbohydrate binding in resistance of B. tengophila infection to S. mansoni is still not fully understood, but the data suggest that there may be a correlation to its presence with susceptibility or resistance to the parasite.
Full Text Available The incidence of opportunistic fungal infections has increased in recent decades due to the growing proportion of immunocompromised patients in our society. Candida krusei has been described as a causative agent of disseminated fungal infections in susceptible patients. Although its prevalence remains low among yeast infections (2-5%, its intrinsic resistance to fluconazole makes this yeast important from epidemiologic aspects. Non mammalian organisms are feasible models to study fungal virulence and drug efficacy. In this work we have used the lepidopteran Galleria mellonella and the nematode Caenorhabditis elegans as models to assess antifungal efficacy during infection by C. krusei. This yeast killed G. mellonella at 25, 30 and 37°C and reduced haemocytic density. Infected larvae melanized in a dose-dependent manner. Fluconazole did not protect against C. krusei infection, in contrast to amphotericin B, voriconazole or caspofungin. However, the doses of these antifungals required to obtain larvae protection were always higher during C. krusei infection than during C. albicans infection. Similar results were found in the model host C. elegans. Our work demonstrates that non mammalian models are useful tools to investigate in vivo antifungal efficacy and virulence of C. krusei.
Nielsen, Line; Søgaard, Mette; Jensen, Trine Hammer
The mechanisms behind the in vivo virulence of immunosuppressive wild-type Morbillivirus infections are still not fully understood. To investigate lymphotropism and host responses we have selected the natural host model of canine distemper virus (CDV) infection in mink. This model displays multis...... in PBMCs was investigated throughout the acute infections. We observed Th1- and Th2-type cytokine responses beginning in the prodromal phase, and late inflammatory responses were shared between the wild-type infections.......The mechanisms behind the in vivo virulence of immunosuppressive wild-type Morbillivirus infections are still not fully understood. To investigate lymphotropism and host responses we have selected the natural host model of canine distemper virus (CDV) infection in mink. This model displays...... multisystemic infection similar to measles virus (MV) and rinderpest virus (RPV) infections in their susceptible natural hosts. The wild-type CDVs investigated provoked marked virulence differences inducing mild versus marked to severe acute disease. The mildly virulent wild-type induced transient lymphopenia...
Virtanen, S; Nikunen, S; Korkeala, H
Altogether, 369 pathogenic Yersinia enterocolitica isolates from 1,118 fecal samples collected from 22 pig farms of different production types were characterized by biotyping, serotyping, and genotyping using multiple-locus variable-number tandem repeats analysis. We investigated the distribution of the different genotypes at the farm level and their association with different farm conditions. Pigs were found to carry and transmit Y. enterocolitica between farms, because the same genotypes were found on farms that had previously transported the pigs between them. The purchase of new animals for the farms associated significantly with the number of different multiple-locus variable-number tandem repeats analysis types of Y. enterocolitica found within a farm. Some genotypes seemed to persist on farms for years. The results of this study show that pigs purchased from infected herds transmit Y. enterocolitica infection between farms. Certain pig farms may act as long-term sources of infection.
Full Text Available Salmonella Typhimurium sequence type (ST 313 produces septicemia in infants in sub-Saharan Africa. Although there are known genetic and phenotypic differences between ST313 strains and gastroenteritis-associated ST19 strains, conflicting data about the in vivo virulence of ST313 strains have been reported. To resolve these differences, we tested clinical Salmonella Typhimurium ST313 and ST19 strains in murine and rhesus macaque infection models. The 50% lethal dose (LD50 was determined for three Salmonella Typhimurium ST19 and ST313 strains in mice. For dissemination studies, bacterial burden in organs was determined at various time-points post-challenge. Indian rhesus macaques were infected with one ST19 and one ST313 strain. Animals were monitored for clinical signs and bacterial burden and pathology were determined. The LD50 values for ST19 and ST313 infected mice were not significantly different. However, ST313-infected BALB/c mice had significantly higher bacterial numbers in blood at 24 h than ST19-infected mice. ST19-infected rhesus macaques exhibited moderate-to-severe diarrhea while ST313-infected monkeys showed no-to-mild diarrhea. ST19-infected monkeys had higher bacterial burden and increased inflammation in tissues. Our data suggest that Salmonella Typhimurium ST313 invasiveness may be investigated using mice. The non-human primate results are consistent with clinical data, suggesting that ST313 strains do not cause diarrhea.
Mukaratirwa, S; Munjere, I F; Takawira, M; Chingwena, G
Gastrodiscosis outbreaks due to Gastrodiscus aegyptiacus were recorded in horses in the vicinity of Harare, Zimbabwe, in the absence of Bulinus forskalii, B. senegalensis and Cleopatra sp. which are considered to be the only intermediate host snails. This suggested the possibility of other snail species acting as intermediate hosts in the life cycle of the trematode. A study was carried out to determine the susceptibility of 7 freshwater snail species to infection with G. aegyptiacus. First generation (F-1) of 5 freshwater pulmonate snail species, Bulinus tropicus, Bulinus globosus, Biomphalaria pfeifferi, Helisoma dyuri and Physa acuta that were bred in the laboratory, and 2 prosobranch snail species, Melanoides tuberculata and Cleopatra sp. that were collected from the field were used in this study. Data pertaining to mortalities and cercariae shedding were recorded throughout the experimental period. The prosobranch snails, M. tuberculata and Cleopatra sp. were susceptible to G. aegyptiacus with a minimum prepatent period of 45 days and 54 days, respectively. Bulinus tropicus, P. acuta and H. duryi were susceptible as evidenced by the presence of different generations of rediae and mature cercariae on dissection at 59 days post-infection although attempts to induce the snails to shed from 28 days post-infection did not produce cercariae. Bulinus globosus and Bio. pfeifferi were refractory to infection. The results revealed the ability of G. aegyptiacus to infect M. tuberculata, Cleopatara sp., B. tropicus, P. acuta and H. duryi under experimental conditions and this may explain the recorded outbreaks of gastrodiscosis in equine populations in Zimbabwe in the absence of the known intermediate hosts. Bulinus tropicus is considered as the most likely major intermediate host of G. aegyptiacus because of its wide distribution in Zimbabwe and is well adapted to a wide variety of environments.
Full Text Available Gastrodiscosis outbreaks due to Gastrodiscus aegyptiacus were recorded in horses in the vicinity of Harare, Zimbabwe, in the absence of Bulinus forskalii, B. senegalensis and Cleopatra sp. which are considered to be the only intermediate host snails. This suggested the possibility of other snail species acting as intermediate hosts in the life cycle of the trematode. A study was carried out to determine the susceptibility of 7 freshwater snail species to infection with G. aegyptiacus. First generation (F-1 of 5 freshwater pulmonate snail species, Bulinus tropicus, Bulinus globosus, Biomphalaria pfeifferi, Helisoma dyuri and Physa acuta that were bred in the laboratory, and 2 prosobranch snail species, Melanoides tuberculata and Cleopatra sp. that were collected from the field were used in this study. Data pertaining to mortalities and cercariae shedding were recorded throughout the experimental period. The prosobranch snails, M. tuberculata and Cleopatra sp. were susceptible to G. aegyptiacus with a minimum prepatent period of 45 days and 54 days, respectively. Bulinus tropicus, P. acuta and H. duryi were susceptible as evidenced by the presence of different generations of rediae and mature cercariae on dissection at 59 days post-infection although attempts to induce the snails to shed from 28 days post-infection did not produce cercariae. Bulinus globosus and Bio. Pfeifferi were refractory to infection. The results revealed the ability of G. aegyptiacus to infect M. tuberculata, Cleopatara sp., B. tropicus, P. acuta and H. duryi under experimental conditions and this may explain the recorded outbreaks of gastrodiscosis in equine populations in Zimbabwe in the absence of the known intermediate hosts. Bulinus tropicus is considered as the most likely major intermediate host of G. aegyptiacus because of its wide distribution in Zimbabwe and is well adapted to a wide variety of environments.
Roberts, D H; Lucas, M H; Wibberley, G; Swallow, C
Steers and calves were experimentally infected with bovine leukosis virus. The virus was isolated from the blood and from the tracheal and bronchoalveolar washings before antibodies could be detected in the serum. Bovine leukosis virus was not detected during any period in the blood plasma.
Inger K. Damon
Full Text Available An ideal animal model for the study of a human disease is one which utilizes a route of infection that mimics the natural transmission of the pathogen; the ability to obtain disease with an infectious dose equivalent to that causing disease in humans; as well having a disease course, morbidity and mortality similar to that seen with human disease. Additionally, the animal model should have a mode(s of transmission that mimics human cases. The development of small animal models for the study of monkeypox virus (MPXV has been quite extensive for the relatively short period of time this pathogen has been known, although only a few of these models have been used to study anti-poxvirus agents. We will review those MPXV small animal models that have been developed thus far for the study of therapeutic agents.
Crocker, P.R.; Blackwell, J.M.; Bradley, D.J. (London School of Hygiene and Tropical Medicine (UK))
Reciprocal radiation bone marrow chimaeras were made between H-2-compatible strains of mice innately resistant or susceptible to visceral leishmaniasis. In initial experiments, susceptibility but not resistance to Leishmania donovani could be transferred with donor bone marrow into irradiated recipients. In subsequent experiments it was possible to transfer both resistance and susceptibility. This was achieved either by selecting more radiosensitive mouse strains as susceptible recipients, or alternatively by increasing the irradiation dose for the susceptible recipients used in the initial experiments. Using the higher irradiation dose, successful transfer of resistance and susceptibility between congenic mice carrying the Lshsup(r) and Lshsup(s) alleles on the more radioresistant B10 genetic background provided firm evidence that the results obtained in this study were specifically related to expression of the Lsh gene. It is concluded that Lsh gene-controlled resistance and susceptibility to L. donovani is determined by bone marrow-derived cells. The cell type(s) involved is likely to be of the macrophage lineage.
Full Text Available Herpesviruses of humans and animals cause severe diseases that influence not only the health and epidemiological status but are also economically important in the context of food production. The members of Herpesviridae are host specific agents that also share many properties that potentially make them capable of crossing the species barriers. The objective of presented review paper was to summarize the relationship between herpesviruses of animals and humans and their zoonotic potential. In humans, the most epidemiologically important herpesviruses are represented by Human herepesvirus-1 and Human herpesvirus-2, which are commonly known as herpes simplex virus type 1 and 2, varicella-zooster virus (VZV, Epstein-Barr virus (EBV, Kaposi’s Sarcoma-associated herpesvirus (KSHV, cytomegalovirus (CMV, as well as Human herpesviruses: HHV-6A, HHV-6B, and HHV-7. However, in terms of the potential to cross the species barrier, there are a few herpesviruses, including B virus disease (CeHV-1, Marek’s disease virus (MDV, Equid herpesvirus-1 (EHV-1 or pseudorabies virus (PRV, which are potentially able to infect different hosts. To summarize, in advantageous conditions the host specific herpesviruses may pose a threat for public health but also may exert a negative impact on the economical aspects of animal production. The most probable of these are zoonotic infections caused by B virus disease; however, close contact between infected animal hosts and humans may lead to transmission and replication of other Herpesviridae members.
Full Text Available Herpesviruses of humans and animals cause severe diseases that influence not only the health and epidemiological status but are also economically important in the context of food production. The members of[i] Herpesviridae[/i] are host specific agents that also share many properties that potentially make them capable of crossing the species barriers. The objective of presented review paper was to summarize the relationship between herpesviruses of animals and humans and their zoonotic potential. In humans, the most epidemiologically important herpesviruses are represented by Human herepesvirus-1 and Human herpesvirus-2, which are commonly known as herpes simplex virus type 1 and 2, varicella-zooster virus (VZV, Epstein-Barr virus (EBV, Kaposi’s Sarcoma-associated herpesvirus (KSHV, cytomegalovirus (CMV, as well as Human herpesviruses: HHV-6A, HHV-6B, and HHV-7. However, in terms of the potential to cross the species barrier, there are a few herpesviruses, including B virus disease (CeHV-1, Marek’s disease virus (MDV, Equid herpesvirus-1 (EHV-1 or pseudorabies virus (PRV, which are potentially able to infect different hosts. To summarize, in advantageous conditions the host specific herpesviruses may pose a threat for public health but also may exert a negative impact on the economical aspects of animal production. The most probable of these are zoonotic infections caused by B virus disease; however, close contact between infected animal hosts and humans may lead to transmission and replication of other [i]Herpesviridae[/i] members.
Kammalac Ngouana, T; Dongtsa, J; Kouanfack, C; Tonfack, C; Fomena, S; Mallié, M; Delaporte, E; Boyom, F-Fekam; Bertout, S
Cryptococcal meningitis is a mycosis encountered especially in patients with Acquired Immunodeficiency Syndrome and is fatal in the absence of treatment. Information on epidemiology, diagnosis and susceptibility profile to antifungal drugs, are scarce in Cameroon. Authors evaluated the diagnosis possibilities of the cryptococcal meningitis in Cameroon, and studied the antifungal susceptibility of isolated strains to fluconazole, used as first line treatment of the disease in Cameroon. Between December 2009 and July 2011, 146 cerebrospinal fluids obtained from HIV patients with suspicion of meningitis were analysed. The diagnosis procedure involved macroscopic and cyto-chemical analysis, India ink test, culture on Sabouraud chloramphenicol medium and antigen latex agglutination test. Antifungal susceptibility testing of isolated strains to fluconazole was done by the E-test(®) method. The diagnosis of cryptococcal meningitis gave 28.08% positive cases. Among these patients, 80% were at stages III and IV and 20% at stage I of the HIV infection, according to the WHO previous classification. Cyto-chemical analysis showed current findings in the case of cryptococcal meningitis. India ink test and latex agglutination test exhibited very high sensitivity and specificity (>94%). Fluconazole antifungal susceptibility testing gave MICs lower than 32μg/mL to 92.7% of isolated strains and MICs greater than this value to 7.3% of isolates. These results showed that cryptococcal meningitis remains a real problem among HIV infected patients in Yaoundé. The emergence of fluconazole reduced susceptibility strains is worrying. Nevertheless, efficacy of rapid detection tests is interesting because this will help in rapid diagnosis and treatment of patients. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
López Hernández, Yamilé; Yero, Daniel; Pinos-Rodríguez, Juan M.; Gibert, Isidre
Biological disease models can be difficult and costly to develop and use on a routine basis. Particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. When infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. Therefore, alternative and easy to handle models of experimental infections are still needed to test the virulence of bacterial lung pathogens. Because non-mammalian models have less ethical and cost constraints as a subjects for experimentation, in some cases would be appropriated to include these models as valuable tools to explore host–pathogen interactions. Numerous scientific data have been argued to the more extensive use of several kinds of alternative models, such as, the vertebrate zebrafish (Danio rerio), and non-vertebrate insects and nematodes (e.g., Caenorhabditis elegans) in the study of diverse infectious agents that affect humans. Here, we review the use of these vertebrate and non-vertebrate models in the study of bacterial agents, which are considered the principal causes of lung injury. Curiously none of these animals have a respiratory system as in air-breathing vertebrates, where respiration takes place in lungs. Despite this fact, with the present review we sought to provide elements in favor of the use of these alternative animal models of infection to reveal the molecular signatures of host–pathogen interactions. PMID:25699030
Barbara M Schulte
Full Text Available Coxsackie B viruses (CVBs and echoviruses (EVs form the Human Enterovirus-B (HEV-B species within the family Picornaviridae. HEV-B infections are widespread and generally cause mild disease; however, severe infections occur and HEV-B are associated with various chronic diseases such as cardiomyopathy and type 1 diabetes. Dendritic cells (DCs are the professional antigen-presenting cells of our immune system and initiate and control immune responses to invading pathogens, yet also maintain tolerance to self-antigens. We previously reported that EVs, but not CVBs, can productively infect in vitro generated monocyte-derived DCs. The interactions between HEV-B and human myeloid DCs (mDCs freshly isolated from blood, however, remain unknown. Here, we studied the susceptibility and responses of BDCA1(+ mDC to HEV-B species and found that these mDC are susceptible to EV, but not CVB infection. Productive EV7 infection resulted in massive, rapid cell death without DC activation. Contrary, EV1 infection, which resulted in lower virus input at the same MOI, resulted in DC activation as observed by production of type I interferon-stimulated genes (ISGs, upregulation of co-stimulatory and co-inhibitory molecules (CD80, CD86, PDL1 and production of IL-6 and TNF-α, with a relative moderate decrease in cell viability. EV1-induced ISG expression depended on virus replication. CVB infection did not affect DC viability and resulted in poor induction of ISGs and CD80 induction in part of the donors. These data show for the first time the interaction between HEV-B species and BDCA1(+ mDCs isolated freshly from blood. Our data indicate that different HEV-B species can influence DC homeostasis in various ways, possibly contributing to HEV-B associated pathology.
Skuterud, L.; Strand, P. [Norwegian Radiation Protection Authority (Norway); Howard, B.J. [Inst. of Terrestrial Ecology (United Kingdom)
The radionuclides of most concern with respect to contamination of animals after a nuclear accident are radioiodine, radiocaesium and radiostrontium (ICRP 30, 1979). Of the other significant anthropogenic radionuclides likely to be released in most accidents, only small proportions of that ingested will be absorbed in an animals gut, and the main animal products, milk and meat, will not normally be contaminated to a significant extent. Animal products will mostly be contaminated as a result of ingestion of contaminated feed and possibly, but to a much lesser extent, from inhalation (for radioiodine only). Direct external contamination of animals is of little or no consequence in human food production. Radioiodine and radiostrontium are important with respect to contamination of milk; radiocaesium contaminates both milk and meat. The physical and chemical form of a radionuclide can influence its absorption in the animal gut. For example, following the Chernobyl accident radiocaesium incorporated into vegetation by root uptake was more readily absorbed than that associated with the original deposit. The transfer of radiocaesium and radiostrontium to animals will be presented both as transfer coefficients and aggregated transfer coefficients. For most animal meat products, only radiocaesium is important as other radionuclides do not significantly contaminate muscle. Farm animal products are the most important foodstuff determining radiocaesium intake by the average consumer in the Nordic countries. The major potential source of radioiodine and radiostrontium to humans is milk and milk products. Of the different species, the smaller animals have the highest transfer of radiocaesium from fodder to meat and milk. (EG). 68 refs.
A K Kapoor
Full Text Available The aim of present study to analyze the occurrence and in-vitro antimicrobial susceptibility of bacterial pathogens isolated from surgical wound infections. Specimens from a total of 129 patients undergoing either emergency or elective surgery were collected from infected sites or stitch lines and inoculated onto appropriate media. The bacterial cultures were identified utilizing standard microbiological and biochemical methods. Isolates were tested for susceptibility to antimicrobials using the Kirby Bauer disk diffusion method. Statistical analysis was performed using the chi-square test. Of 129 patients investigated (62 emergency and 67 elective surgery cases, bacterial isolates were isolated with almost equal frequency both from emergency and elective surgery cases. Of 108 (83.72% culture positive samples, 62 (57.41% were Gram negative, 39 (36.11% Gram positive, and 7 (6.48% showed multiple organisms. Of total 115 bacteria isolated (101 single and 7 double organisms culture positive, 33 (28.69% were Escherichia coli and were also the commonest; followed by Staphylococcus aureus, 30 (26.09% cases. S. aureus and Streptococcus spp. showed maximum susceptibility (100% to linezolid and vancomycin. Maximum susceptibility of E. coli was observed to ciprofloxacin (75.7%, followed by gentamicin (54.5%; of Klebsiella spp. to ceftriaxone and gentamicin (66.6% each, of Proteus spp. to gentamicin (70% followed by ciprofloxacin (60%, and of Pseudomonas aeruginosa to piperacillin (100% and tobramycin (71.4%. E. coli and S. aureus were the most common and Salmonella spp. and Acinetobacter spp. were the least common organism causing surgical site infections. The definitive therapy included ciprofloxacin and gentamicin for E. coli; linezolid and vancomycin for S. aureus and Streptococcus spp; ceftriaxone and ciprofloxacin for Klebsiella spp., Citrobacter spp., acinetobacter spp and Salmonella spp.
Full Text Available Individual differences in susceptibility to human immunodeficiency virus type 1 (HIV-1 infection have been of interest for decades. We aimed to determine the contribution of large isoform of Mammalian DnaJ (MRJ-L, a HIV-1 Vpr-interacting cellular protein, to this natural variation. Expression of MRJ-L in monocyte-derived macrophages was significantly higher in HIV-infected individuals (n = 31 than their uninfected counterparts (n = 27 (p = 0.009. Fifty male homosexual subjects (20 of them are HIV-1 positive were further recruited to examine the association between MRJ-L levels and occurrence of HIV infection. Bayesian multiple logistic regression revealed that playing a receptive role and increased levels of MRJ-L in macrophages were two risk factors for HIV-1 infection. A 1% rise in MRJ-L expression was associated with a 1.13 fold (95% CrI 1.06–1.29 increase in odds of contracting HIV-1 infection. Ex vivo experiments revealed that MRJ-L facilitated Vpr-dependent nuclear localization of virus. Infection of macrophage-tropic strain is a critical step in HIV-1 transmission. MRJ-L is a critical factor in this process; hence, subjects with higher macrophage MRJ-L levels are more vulnerable to HIV-1 infection.
Maliogka, Varvara I; Calvo, María; Carbonell, Alberto; García, Juan Antonio; Valli, Adrian
HCPro, the RNA-silencing suppressor (RSS) of viruses belonging to the genus Potyvirus in the family Potyviridae, is a multifunctional protein presumably involved in all essential steps of the viral infection cycle. Recent studies have shown that plum pox potyvirus (PPV) HCPro can be replaced successfully by cucumber vein yellowing ipomovirus P1b, a sequence-unrelated RSS from a virus of the same family. In order to gain insight into the requirement of a particular RSS to establish a successful potyviral infection, we tested the ability of different heterologous RSSs from both plant- and animal-infecting viruses to substitute for HCPro. Making use of engineered PPV chimeras, we show that PPV HCPro can be replaced functionally by some, but not all, unrelated RSSs, including the NS1 protein of the mammal-infecting influenza A virus. Interestingly, the capacity of a particular RSS to replace HCPro does not correlate strictly with its RNA silencing-suppression strength. Altogether, our results suggest that not all suppression strategies are equally suitable for efficient escape of PPV from the RNA-silencing machinery. The approach followed here, based on using PPV chimeras in which an under-consideration RSS substitutes for HCPro, could further help to study the function of diverse RSSs in a 'highly sensitive' RNA-silencing context, such as that taking place in plant cells during the process of a viral infection.
Pauline B van de Weert-van Leeuwen
Full Text Available Regular moderate exercise has been suggested to exert anti-inflammatory effects and improve immune effector functions, resulting in reduced disease incidence and viral infection susceptibility. Whether regular exercise also affects bacterial infection susceptibility is unknown. The aim of this study was to investigate whether regular voluntary exercise wheel running prior to a pulmonary infection with bacteria (P. aeruginosa affects lung bacteriology, sickness severity and phagocyte immune function in mice. Balb/c mice were randomly placed in a cage with or without a running wheel. After 28 days, mice were intranasally infected with P. aeruginosa. Our study showed that regular exercise resulted in a higher sickness severity score and bacterial (P. aeruginosa loads in the lungs. The phagocytic capacity of monocytes and neutrophils from spleen and lungs was not affected. Although regular moderate exercise has many health benefits, healthy mice showed increased bacterial (P. aeruginosa load and symptoms, after regular voluntary exercise, with perseverance of the phagocytic capacity of monocytes and neutrophils. Whether patients, suffering from bacterial infectious diseases, should be encouraged to engage in exercise and physical activities with caution requires further research.
Quispe Calla, N E; Vicetti Miguel, R D; Boyaka, P N; Hall-Stoodley, L; Kaur, B; Trout, W; Pavelko, S D; Cherpes, T L
Depot-medroxyprogesterone acetate (DMPA) is a hormonal contraceptive especially popular in areas with high prevalence of HIV and other sexually transmitted infections (STI). Although observational studies identify DMPA as an important STI risk factor, mechanisms underlying this connection are undefined. Levonorgestrel (LNG) is another progestin used for hormonal contraception, but its effect on STI susceptibility is much less explored. Using a mouse model of genital herpes simplex virus type 2 (HSV-2) infection, we herein found that DMPA and LNG similarly reduced genital expression of the desmosomal cadherin desmoglein-1α (DSG1α), enhanced access of inflammatory cells to genital tissue by increasing mucosal epithelial permeability, and increased susceptibility to viral infection. Additional studies with uninfected mice revealed that DMPA-mediated increases in mucosal permeability promoted tissue inflammation by facilitating endogenous vaginal microbiota invasion. Conversely, concomitant treatment of mice with DMPA and intravaginal estrogen restored mucosal barrier function and prevented HSV-2 infection. Evaluating ectocervical biopsy tissue from women before and 1 month after initiating DMPA remarkably revealed that inflammation and barrier protection were altered by treatment identically to changes seen in progestin-treated mice. Together, our work reveals DMPA and LNG diminish the genital mucosal barrier; a first-line defense against all STI, but may offer foundation for new contraceptive strategies less compromising of barrier protection.
Charlotte S McCarroll
Full Text Available African trypanosomiasis (AT, caused by Trypanosoma brucei species, results in both neurological and cardiac dysfunction and can be fatal if untreated. Research on the pathogenesis and treatment of the disease has centred to date on the characteristic neurological symptoms, whereas cardiac dysfunction (e.g. ventricular arrhythmias in AT remains largely unstudied. Animal models of AT demonstrating cardiac dysfunction similar to that described in field cases of AT are critically required to transform our understanding of AT-induced cardiac pathophysiology and identify future treatment strategies. We have previously shown that T. brucei can interact with heart muscle cells (cardiomyocytes to induce ventricular arrhythmias in ex vivo adult rat hearts. However, it is unknown whether the arrhythmias observed ex vivo are also present during in vivo infection in experimental animal models. Here we show for the first time the characterisation of ventricular arrhythmias in vivo in two animal models of AT infection using electrocardiographic (ECG monitoring. The first model utilised a commonly used monomorphic laboratory strain, Trypanosoma brucei brucei Lister 427, whilst the second model used a pleomorphic laboratory strain, T. b. brucei TREU 927, which demonstrates a similar chronic infection profile to clinical cases. The frequency of ventricular arrhythmias and heart rate (HR was significantly increased at the endpoint of infection in the TREU 927 infection model, but not in the Lister 427 infection model. At the end of infection, hearts from both models were isolated and Langendorff perfused ex vivo with increasing concentrations of the β-adrenergic agonist isoproterenol (ISO. Interestingly, the increased frequency of arrhythmias observed in vivo in the TREU 927 infection model was lost upon isolation of the heart ex vivo, but re-emerged with the addition of ISO. Our results demonstrate that TREU 927 infection modifies the substrate of the myocardium
Lindsey, C L; Almeida, M E; Vicari, C F; Carvalho, C; Yaguiu, A; Freitas, A C; Beçak, W; Stocco, R C
Papillomavirus infection in bovines is associated with cutaneous papillomatosis on the hide, udders and other epithelial tissues, as well as in oral respiratory, alimentary and urinary tract mucosa. Bovine papillomavirus (BPV) is also considered the etiological agent of esophageal tumors and the malignant bladder tumors that characterize the clinical condition associated with chronic enzootic hematuria. After infective viral DNA was found in cattle blood and BPV1, 2 and 4 DNA in cattle reproductive and embryonic tissues, we looked for and found BPV DNA in blood, milk, urine, seminal fluid, and spermatozoa of BPV-infected animals. Peripheral blood lymphocyte cultures from BPV-infected animals had high rates of chromosome aberrations, including radial rearrangements that signal oncogenic potential and viral interaction with telomeric regions. The finding of BPV DNA in body fluids and tissues other than the epithelium demonstrates co-infection of other tissues or cell types by papillomavirus and shows the potential role of lymphocytes, seminal fluid and spermatozoa in BPV transmission. Our findings reinforce a peremptory need for prophylactic and therapeutic instruments to curtail this disease in bovine livestock.
Ventura, Luciana L A; Oliveira, Dirce R; Viana, João C; Santos, Joseph F G; Caliari, Marcelo V; Gomes, Maria A
Giardiasis is one of the most common parasitic diseases worldwide, and the disease is an important cause of diarrhoea and malabsorption in children and immunosuppressed individuals. However, there is no evidence that characterises malnutrition as an aggravating factor for this disease. We evaluated changes in villi structures to examine the association between malnutrition and Giardia lamblia infection. We used 32 gerbils, divided into 4 groups: Control (CT) and Control Infected (CTIn), which each received a 20% protein diet, Malnourished (MN) and Malnourished Infected (MNIn), which each received a 5% protein diet. Groups CTIn and MNIn were inoculated with 1×10(6) trophozoites of G. lamblia, while the remaining groups were mock infected. Seven days post-infection, all groups were sacrificed, and the proximal portions of the small intestines were collected for the analysis of villus height, mucus area and extent of Giardia infection. Gerbils fed with a low-protein diet had significantly lower body weights. Malnourished infected animals presented significantly increased production of mucus, suggesting a synergism occurs between malnutrition and Giardiasis, potentially to control the adhesion of Giardia in the mucosa. Villus height was significantly lower in group MNIn compared to CTIn. This work suggests that malnutrition contributes to severity of Giardiasis by decreasing the intestinal absorption capacity via shortening of the villi. Copyright © 2013 Elsevier Inc. All rights reserved.
Bentley, R Timothy; Taylor, Amanda R; Thomovsky, Stephanie A
Small animal mycoses vary geographically. Different clinical presentations are seen in animals with infection of the central nervous system (CNS), including multifocal meningoencephalomyelitis, intracranial lesions that accompany sinonasal lesions, rapidly progressive ventriculitis, or solitary granuloma of the brain or spinal cord. Systemic, nasal, or extraneural clinical signs are common but, especially in granuloma cases, do not always occur. Surgery may have a diagnostic and therapeutic role in CNS granuloma. There have been recent advancements in serology. Fluconazole, voriconazole, and posaconazole cross the blood-brain barrier, but voriconazole is neurotoxic to cats. Liposomal and lipid-encapsulated formulations of amphotericin B are preferred. Copyright © 2017 Elsevier Inc. All rights reserved.
Gündoğdu, Aycan; Kılıç, Hüseyin; Ulu Kılıç, Ayşegül; Kutateladze, Mzia
Skin and soft tissue infections (SSTIs) may represent a wide clinical spectrum from cellulitis to high-mortality associated necrotizing fasciitis. Limitations in therapy due to the multiple drug resistance, leads to increase in the morbidity and mortality rates, especially in complicated SSTIs such as diabetic foot, decubitus, and surgical wound infections. Therefore, alternative treatment strategies other than antibiotics are needed in appropriate clinical conditions. "Bacteriophage therapy", which is an old method and has been used as part of standard treatment in some countries such as Georgia and Russia, has again become popular worldwide. The aim of this study was to investigate the in vitro susceptibilities of multidrug-resistant (MDR) pathogens isolated from patients with complicated SSTIs, against standard bacteriophage (phage) cocktails. Six different ready-made phage preparations [Pyophage, Intestiphage, ENKO, SES, Fersisi and Staphylococcal Bacteriophage (Sb)] used in this study have been provided by G. Eliava Institute, Georgia. Because of the absence of ready-made phage preparations for Acinetobacter baumannii and Klebsiella pneumoniae, Φ1-Φ7 and ΦKL1- ΦKL3 phages were used provided from the same institute's phage library, respectively. Isolation and identification of the pathogens from abscess and wound samples of patients with SSTIs were performed by conventional methods and automatized VITEK(®)-2 (bioMerieux, ABD) system. Antimicrobial susceptibility testing was conducted complying CLSI standards' and the bacteria that were resistant to at least two different antibiotic groups were considered as MDR. Accordingly, a total of 33 isolates, nine of them were E.coli (8 ESBL and 1 ESBL + carbapenemase positive); nine were MDR P.aeruginosa; nine were MDR A.baumannii; three were methicillin-resistant Staphylococcus aureus (MRSA) and three were K.pneumoniae (1 ESBL, 1 carbapenemase and 1 ESBL + carbapenemase positive) were included in the study. The
Baer, Boris; Schmid-Hempel, Paul
AbstractFemale multiple mating with different males (polyandry) can be advantageous because the resulting genetic heterogeneity among offspring reduces the effects of parasitism. However, the underlying assumption that offspring fathered by different males vary in their susceptibility to parasites...... conditions, workers from different sire groups, forming a patriline within a given colony, indeed differ in their susceptibility to the common intestinal parasite, Crithidia bombi, and do so independently of queen mating frequency....
Ouellette, G.B.; Rioux, D.; Simard, M.; Baayen, R.P.
Uncommon, opaque particles (of approximately 20-22 nm, referred to as OP), aggregating into paracrystalloids occurred only next to colonized cells in carnation plants of either a susceptible or resistant cultivar (cv.) infected with Fusarium oxysporum f.sp. dianthi. In the susceptible plant, those
Full Text Available BACKGROUND: A generalized decline in populations of Old World avian scavengers is occurring on a global scale. The main cause of the observed crisis in continental populations of these birds should be looked for in the interaction between two factors -- changes in livestock management, including the increased use of pharmaceutical products, and disease. Insular vertebrates seem to be especially susceptible to diseases induced by the arrival of exotic pathogens, a process often favored by human activities, and sedentary and highly dense insular scavengers populations may be thus especially exposed to infection by such pathogens. Here, we compare pathogen prevalence and immune response in insular and continental populations of the globally endangered Egyptian vulture under similar livestock management scenarios, but with different ecological and evolutionary perspectives. METHODS/PRINCIPAL FINDINGS: Adult, immature, and fledgling vultures from the Canary Islands and the Iberian Peninsula were sampled to determine a the prevalence of seven pathogen taxa and b their immunocompetence, as measured by monitoring techniques (white blood cells counts and immunoglobulins. In the Canarian population, pathogen prevalence was higher and, in addition, an association among pathogens was apparent, contrary to the situation detected in continental populations. Despite that, insular fledglings showed lower leukocyte profiles than continental birds and Canarian fledglings infected by Chlamydophila psittaci showed poorer cellular immune response. CONCLUSIONS/SIGNIFICANCE: A combination of environmental and ecological factors may contribute to explain the high susceptibility to infection found in insular vultures. The scenario described here may be similar in other insular systems where populations of carrion-eaters are in strong decline and are seriously threatened. Higher susceptibility to infection may be a further factor contributing decisively to the extinction
Sekulovic, Ognjen; Garneau, Julian R; Néron, Audrey; Fortier, Louis-Charles
Clostridium difficile is a Gram-positive pathogen infecting humans and animals. Recent studies suggest that animals could represent potential reservoirs of C. difficile that could then transfer to humans. Temperate phages contribute to the evolution of most bacteria, for example, by promoting the transduction of virulence, fitness, and antibiotic resistance genes. In C. difficile, little is known about their role, mainly because suitable propagating hosts and conditions are lacking. Here we report the isolation, propagation, and preliminary characterization of nine temperate phages from animal and human C. difficile isolates. Prophages were induced by UV light from 58 C. difficile isolates of animal and human origins. Using soft agar overlays with 27 different C. difficile test strains, we isolated and further propagated nine temperate phages: two from horse isolates (ΦCD481-1 and ΦCD481-2), three from dog isolates (ΦCD505, ΦCD506, and ΦCD508), and four from human isolates (ΦCD24-2, ΦCD111, ΦCD146, and ΦCD526). Two phages are members of the Siphoviridae family (ΦCD111 and ΦCD146), while the others are Myoviridae phages. Pulsed-field gel electrophoresis and restriction enzyme analyses showed that all of the phages had unique double-stranded DNA genomes of 30 to 60 kb. Phages induced from human C. difficile isolates, especially the members of the Siphoviridae family, had a broader host range than phages from animal C. difficile isolates. Nevertheless, most of the phages could infect both human and animal strains. Phage transduction of antibiotic resistance was recently reported in C. difficile. Our findings therefore call for further investigation of the potential risk of transduction between animal and human C. difficile isolates.
Weiland, L.K.; Mesa, M.G.; Maule, A.G.
During experiments in our laboratory to assess the progression and severity of gas bubble trauma (GBT) in juvenile spring chinook salmon Oncorhynchus tshawytscha, we had the opportunity to assess the influence of Renibacterium salmoninarum (Rs), the causative agent of bacterial kidney disease, on the susceptibility of salmon to GBT. We exposed fish with an established infection of Rs to 120% total dissolved gas (TDG) for 96 h and monitored severity of GBT signs in the fins and gills, Rs infection level in kidneys by using an enzyme-linked immunosorbent assay (ELISA), and mortality. Mortality occurred rapidly after exposure to 120% TDG, with a LT20 (time necessary to kill 20% of the population) of about 37 h, which is at a minimum about 16% earlier than other bioassays we have conducted using fish that had no apparent signs of disease. Fish that died early (from 31 to 36 h and from 49 to 52 h) had significantly higher infection levels (mean ?? SE ELISA absorbance = 1.532 ?? 0.108) than fish that survived for 96h (mean ?? SE ELISA absorbance = 0.828 ?? 0.137). Fish that died early also had a significantly greater number of gill filaments occluded with bubbles than those that survived 96 h. Conversely, fish that survived for 96 h had a significantly higher median fin severity ranking than those that died early. Our results indicate that fish with moderate to high levels of Rs infection are more vulnerable to the effects of dissolved gas supersaturation (DGS) and die sooner than fish with lower levels of Rs infection. However, there is a substantial amount of individual variation in susceptibility to the apparent cumulative effects of DGS and Rs infection. Collectively, our findings have important implications to programs designed to monitor the prevalence and severity of GBT in juvenile salmonids in areas like the Columbia River basin and perhaps elsewhere.
Neurons are one of the few cell types in the human body that do not support HIV type-1 (HIV-1) replication. Although the lack of key receptors is a major obstacle to infection, studies suggest that additional functions inhibit virus replication to explain the exquisite resistance of neurons to HIV-1. However, specific neuronal factors that may explain this resistance remain to be discovered. In a screen for antiviral factors using a fibroblast line chemically mutagenized and selected for resistance to retroviral infection, we recently identified induction of rat FEZ1 (fasciculation and elongation protein zeta-1), a brain-specific protein, as the cause of this resistance. When exogenously expressed in nonneuronal cell lines rat FEZ1 blocked nuclear entry of retroviral DNA. Here, we demonstrate that among human brain cells, neurons naturally express high levels of FEZ1 compared to astrocytes or microglia cells and are correspondingly less susceptible to infection with pseudotyped HIV-1 that bypasses receptor-mediated viral entry. Demonstrating that endogenous FEZ1 was functionally important in the resistance of neurons to HIV-1 infection, siRNA-mediated knockdown of endogenous FEZ1 increased the infectivity of neurons while sensitive brain cell types like microglia became more resistant upon FEZ1 overexpression. In addition, FEZ1 expression was not induced in response to IFN treatment. As such, in contrast to other widely expressed, IFN-inducible antiviral factors, FEZ1 appears to represent a unique neuron-specific determinant of cellular susceptibility to infection in a cell type that is naturally resistant to HIV-1.
Schroeder, Sabine; Blome, Sandra; Koenen, Frank
of vaccinated from infected animals (DIVA) is not possible. Newly developed modified live marker vaccines allow a DIVA strategy based on the use of enzyme linked immunosorbent assay (ELISA) tests. The aim of this study was to evaluate CSF virus (CSFV) Antibody ELISAs, com-mercially available in Europe......, for their diagnostic sensitivity as well as for their potential in differentiating between infected and marker vaccinated animals. Two newly available ELISAs were included into the tests, the Priocheck® CSFV Erns ELISA, a special DIVA test, and the LDL Pigtype® CSFV Antibody ELISA. An inter-laboratory comparison test...... with four EU national CSF reference labora-tories and one EU reference laboratory participating was organized. Seven differ-ent CSFV antibody ELISA test kits, targeting distinct antibodies (against E2, Erns, NS3) were provided to the participating laboratories together with a set of 41 samples. This set...
Berti, Fernanda Costa Brandão; Pereira, Ana Paula Lombardi; Trugilo, Kleber Paiva; Cebinelli, Guilherme Cesar Martelossi; Silva, Lorena Flor da Rosa Santos; Lozovoy, Marcell Alysson Batisti; Simão, Andréa Name Colado; Watanabe, Maria Angelica Ehara; de Oliveira, Karen Brajão
Interleukin-10 (IL-10) influences HPV infection and viral persistence, favoring cervical immunosuppression and cervical carcinogenesis. IL-10 levels may be influenced by HPV itself and by IL-10 polymorphisms, including rs1800872 (c.-592C>A). Therefore, we evaluated the influence of IL-10 c.-592C>A polymorphism in HPV infection and in IL-10 plasmatic/cervical levels in HPV infected and non-infected women. The study included 174 infected and 186 non-infected patients. Cervical epithelial scrapings were obtained to determine HPV DNA presence PCR. Peripheral blood samples were obtained to determine IL-10 polymorphism by PCR-RFLP, while IL-10 levels were assessed by ELISA. HPV was more prevalent among allele A carriers (pA polymorphism being associated with HPV infection. As demonstrated by binary logistic regression analysis, heterozygotes [ORadj=2.081 95% CI (1.222-3.544), p=0.007] and homozygotes [ORadj=3.745 95% CI (1.695-8.271), p=0.001] showed approximately 2 and 4 time's greater odds, respectively, of presenting HPV when compared to CC patients. Moreover, HPV infected patients carrying polymorphic allele A showed higher IL-10 cervical levels (p=0.039). Binary logistic regression analysis demonstrated that IL-10 cervical levels were not independently associated to CA+AA genotypes (p=0.162), neither to HPV's presence (p=0.061), thus IL-10 cervical levels are possibly increased because of both HPV and allele A presence. Taken together, these findings suggest that IL-10 c.-592C>A polymorphism is independently associated with HPV infection susceptibility exerting influence on IL-10 cervical levels in HPV infected women, thus contributing to cervical carcinogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.
Garedew, Legesse; Taddese, Ayele; Biru, Tigist; Nigatu, Seleshe; Kebede, Elias; Ejo, Mebrat; Fikru, Abraham; Birhanu, Tamiru
Listeriosis, mostly caused by Listeria monocytogenes species, has become a major concern to public health authorities due to its clinical severity and high mortality rate, particularly in high risk groups. Currently, there is limited information regarding the prevalence and antimicrobial susceptibility profiles of listeria species in ready-to-eat foods of animal origin in Gondar town, Ethiopia. The aim of this study was to determine the prevalence and antimicrobial susceptibility pattern of Listeria species isolated from ready-to-eat food of animal origin from public dinning places in Gondar town, Ethiopia. A cross sectional study on ready-toeat foods of animal origin sampled from major supermarkets, butcher shops, pastry shops, restaurants and hotels was carried out. Culture, biochemical and sugar tests were conducted for listeria species identification and disc diffusion test was performed to study the antimicrobial susceptibility profiles of the isolates. Out of 384 food samples examined, 96 (25%) were positive for Listeria species. Listeria monocytogenes was detected in 24 (6.25%) of the samples. Listeria monocytogenes was isolated from cake, raw meat, ice cream, minced beef, fish, unpasteurized milk and pizza in that order from higher to lower rate. Assessment of antimicrobial susceptibility profile of L. monocytogenes revealed the presence of four multi-drug resistant isolates. The higher resistance rate was recorded for penicillin, nalidixic acid, tetracycline and chloramphenicol, in decreasing order. All L. monocytogenes identified in the current study were sensitive to amoxicillin, cephalothin, cloxacillin, sulfamethoxazole, gentamicin and vancomycin. The presence of L. monocytogenes including drug resistant and multidrug resistant isolates in some ready-to-eat food items is an indicator of the presence of public health hazards to the consumer, particularly to the high-risk groups. Hence awareness creation on food safety and implementation of regulations
Full Text Available The susceptibility of grapevine annual pruning wounds to Phaeomoniella chlamydospora, Phaeoacremonium aleophilum and Diplodia seriata was investigated over three years (2005–2007 in a 15 year-old vineyard, cv. Sauvignon blanc. Vines were pruned each year in January, February and March and the wounds were inoculated weekly with conidial suspensions, and with sterile water as a control. Penetration of the fungi into the wood was assessed after 4 weeks by plating pieces of host tissue on agar medium. The susceptibility of annual pruning wounds, expressed as the infection percentages of inoculated spurs, varied with both the trial year and the fungus inoculated. Average infection percentages of inoculated spurs in the three years were respectively 14.7, 38.5 and 50.9% for Pa. chlamydospora, 31.7, 32.2 and 49.4% for Pm. aleophilum and 84.2, 43.8 and 40.9% for D. seriata. The period of pruning was significant for the infection percentages of all fungi in 2005, and for D. seriata in 2006. Natural infection of control spurs by Pa. chlamydospora (2, 4.4, and 11.7% of spurs in the three years respectively and by Pm. aleophilum (0.3, 1.8, and 6.4% began when average weekly temperatures stabilized around 10°C, while infection by D. seriata (12.2, 12 and 18.3% in the same period occurred even below that threshold. Higher infection percentages of both artificially and naturally infected spurs in 2007 were probably due to the higher temperatures recorded in February and March (besides the use of a more efficient selective medium for the isolation of Pa. chlamydospora and Pm. aleophilum. Only artificial infections with D. seriata showed an opposite trend that cannot be explained by the weather data. Infection of one-year-old wood appeared to be an important factor in disease spread. Spurs remained liable to infections with any of the fungi for up to 4 months after pruning, and isolation percentages could be fairly high also in late spring. As a consequence
Alasaad, Samer; Permunian, Roberto; Gakuya, Francis; Mutinda, Matthew; Soriguer, Ramón C; Rossi, Luca
Abstract Background One of the main aims of forensic investigation is the detection and location of people and substances of interest, such as missing people and illegal drugs. Dogs (Canis lupus var. familiaris) have had an important role in legal and forensic investigations for decades; nonetheless canines’ keen sense of smell has never been utilized in either the surveillance or control of wildlife diseases. The rapid removal and treatment of infected carcasses and/or sick animals is a key ...
Aarestrup, Frank Møller; Hasman, Henrik
A total of 569 different bacterial isolates (156 Salmonella, 202 E. coli, 43 S. aureus, 38 S. hyicus, 52 E. faecalis, 78 E faecium) were tested for susceptibility to copper sulphate, benzalkonium chloride, hydrogen peroxide and chlorhexidine using MIC determinations. A total of 442 isolates were ...... bacterial species to these compounds, and Salmonella especially seems intrinsically less susceptible than the other bacterial species, which might have human health implications. (C) 2004 Elsevier B.V. All rights reserved....
Monleón, Eva; Garza, Ma Carmen; Sarasa, Rocío; Alvarez-Rodriguez, Javier; Bolea, Rosa; Monzón, Marta; Vargas, M Antonia; Badiola, Juan José; Acín, Cristina
In classical scrapie, detection of PrPsc on lymphoreticular system is used for the in vivo and post mortem diagnosis of the disease. However, the sensitivity of this methodology is not well characterised because the magnitude and duration of lymphoid tissue involvement can vary considerably. The aim of the present study was to evaluate the efficiency of detecting PrPsc in rectal mucosa and third-eyelid biopsies. A total of 474 genetically susceptible sheep and 24 goats from three scrapie infected flocks were included in this study. A sample from rectal mucosa and a sample from third-eyelid lymphoid tissue were collected from each animal. Biopsy samples were fixed in formaldehyde and processed for immunohistochemical examination. Animals with negative biopsy results were studied more closely through a post mortem examination of central nervous and lymphoreticular systems and if there was a positive result, additional biopsy sections were further tested. The sensitivity of rectal mucosa and third-eyelid assays were 36% and 40% respectively on initial examination but increased to 48% and 44% respectively after retesting. The results of this field study show a high percentage of infected animals that do not have detectable levels of PrPsc in the biopsied lymphoid tissue, due mainly to the relatively high number of animals with minimal or no involvement of lymphoid tissue in the pathogenesis of the disease. Copyright © 2010 Elsevier B.V. All rights reserved.
Park, Ga Eun; Kang, Cheol-In; Cha, Min Kyeong; Cho, Sun Young; Seok, Hyeri; Lee, Ji Hye; Kim, Ji Yeon; Ha, Young Eun; Chung, Doo Ryeon; Peck, Kyong Ran; Lee, Nam Yong; Song, Jae-Hoon
During recent decades, the rates of multidrug resistance, including resistance to carbapenems, have increased dramatically among Acinetobacter species. Tigecycline has activity against multidrug-resistant Acinetobacter spp, including carbapenem-resistant isolates. However, reports of tigecycline-resistant Acinetobacter spp are emerging from different parts of the world. The purpose of this study was to evaluate potential risk factors associated with tigecycline non-susceptible Acinetobacter bacteremia. The medical records of 152 patients with Acinetobacter bacteremia attending Samsung Medical Center between January 2010 and December 2014 were reviewed. Non-susceptibility to tigecycline was defined as a minimum inhibitory concentration (MIC) of tigecycline ≥4μg/ml. Cases were patients with tigecycline non-susceptible Acinetobacter bacteremia and controls were those with tigecycline-susceptible Acinetobacter bacteremia. Of the 152 patients included in the study, 61 (40.1%) had tigecycline non-susceptible Acinetobacter bacteremia (case group). These patients were compared to 91 patients with tigecycline-susceptible Acinetobacter bacteremia (control group). The case group showed high resistance to other antibiotics (>90%) except colistin (6.6%) and minocycline (9.8%) when compared to the control group, which exhibited relatively low resistance to other antibiotics (<50%). Multivariate analysis showed that recent exposure to corticosteroids (minimum 20mg per day for more than 5 days within 2 weeks) (adjusted odds ratio (OR) 2.887, 95% confidence interval (CI) 1.170-7.126) and carbapenems (within 2 weeks) (adjusted OR 4.437, 95% CI 1.970-9.991) were significantly associated with tigecycline non-susceptible Acinetobacter bacteremia. Although prior exposure to tigecycline was more common in the case group than in the control group (9.8%, 6/61 vs. 2.2%, 2/91; p=0.046), this variable was found not to be a significant factor associated with tigecycline non-susceptibility
Full Text Available As a zoonotic pathogen, Encephalitozoon cuniculi is a cause of serious disease in animals and people. The present study was to evaluate the health status examination of this seropositive animal care worker in our previous study.Blood samples were taken from five workers. CIA test was applied to detect antibodies against E. cuniculi in blood serum. The indirect immunofluorescence antibody test was used as confirmation test. Seropositive worker had a complete medical examination.Only one worker was found to be seropositive according to the results of the serological test. Sera positive to E. cuniculi was confirmed with IFAT and spores were detected in the urine sample of the worker. The worker was treated with albendazole.Rabbits should be examined routinely for the presence of anti-E. cuniculi antibody. People working with laboratory animal should avoid contact with urine and faeces of infected or pay attention to personal hygiene.
Fan, S; Wang, J; Li, Y; Li, J
Intra-abdominal infections (IAIs) caused by ESBLs producing bacteria have become a serious clinical concern worldwide as the prevalence of bacterial resistance to antibiotics continues to increase. The objective of this study was to analyze the bacteriology and antimicrobial susceptibility of ESBLs producers using pus samples from IAIs patients caused by abdominal trauma. A total of 113 pus samples aspirated from IAIs patients were collected. The BACTEC 9120 and Vitek 2 system were used for detecting positive pathogens and confirming ESBLs production. The results of susceptibility were determined following the Clinical Laboratory Standards Institute guidelines. Among the pathogens causing IAIs, Escherichia coli (E. coli) (29.1 %) was the most commonly isolated, followed by Klebsiella pneumoniae (K. pneumoniae) (22.5 %). The incidence rates of ESBLs production among E. coli, K. pneumoniae, and Klebsiella oxytoca were 69.6, 45.1, and 25.0 %, respectively. All pathogens had high resistance rates against studied antibiotics, with imipenem (88.7 %) and ertapenem (90.7 %) remaining the only practical options. Trend analysis documented an increase in ESBLs producing E. coli and K. pneumoniae, and a decrease in susceptibility for carbapenems among ESBLs producing E. coli and K. pneumoniae. Escherichia coli and K. pneumoniae were the major pathogens causing abdominal trauma associated IAIs. The most active agents against ESBLs producing E. coli and K. pneumoniae were ertapenem and imipenem. However, the ESBLs rates were alarmingly high and increasing among IAIs associated gram-negative bacilli infections in China, and most agents exhibited decreased susceptibility against ESBLs producing pathogens.
Luo, Houqiang; Li, Kun; Zhang, Hui; Gan, Ping; Shahzad, Muhammad; Wu, Xiaoxing; Lan, Yanfang; Wang, Jiaxiang
Toxoplasma gondii is a zoonotic protozoan parasite that infects a wide range of warm-blooded animals throughout the world. In the present study, antibodies to T. gondii were determined using a commercial indirect hemagglutination (IHA) test in wild animals in a zoo. Three of 11 giraffes (Giraffa camelopardalis) (27%), 1 of 5 wolves (Canis lupus laniger) (20%), 1 of 6 hippopotamuses (Hippopotamus amphibious) (17%), and 2 of 9 tundra swans (Cygnus columbianus) (22%) were found to be positive. No antibodies were detected in leopards (Panthera pardus), wild geese (Anser cygnoides), and Eastern grey kangaroos (Macropus giganteus). Domestic species from 13 counties of Jiangxi Province, China were also investigated by an indirect hemagglutination (IHA) test. Thirty-five of 340 goats (10%), 94 of 560 water buffaloes (17%), and 4 of 35 cattle (11%) were found to be seropositive. This is the first report of T. gondii infection in animals kept in zoos and domestic animals in this province. © H. Luo et al., published by EDP Sciences, 2017.
Manickam, Cordelia; Reeves, R Keith
Hepatitis C virus (HCV) infection has become a global public health burden costing billions of dollars in health care annually. Even with rapidly advancing scientific technologies this disease still poses a significant threat due to a lack of vaccines and affordable treatment options. The immune correlates of protection and predisposing factors toward chronicity remain major obstacles to development of HCV vaccines and immunotherapeutics due, at least in part, to lack of a tangible infection animal model. This review discusses the currently available animal models for HCV disease with a primary focus on GB virus B (GBV-B) infection of New World primates that recapitulates the dual Hepacivirus phenotypes of acute viral clearance and chronic pathologic disease. HCV and GBV-B are also closely phylogenetically related and advances in characterization of the immune systems of New World primates have already led to the use of this model for drug testing and vaccine trials. Herein, we discuss the benefits and caveats of the GBV-B infection model and discuss potential avenues for future development of novel vaccines and immunotherapies.
Full Text Available Hepatitis C virus (HCV infection has become a global public health burden costing billions of dollars in health care annually. Even with rapidly advancing scientific technologies, this disease still looms large due to a lack of vaccines and affordable treatment options. The immune correlates of protection and predisposing factors towards chronicity remain major obstacles to development of HCV vaccines and immunotherapeutics due, at least in part, to lack of a tangible infection animal model. This review discusses the currently available animal models for HCV disease, with a primary focus on GB virus B (GBV-B infection of New World primates that recapitulates the dual hepacivirus phenotypes of acute viral clearance and chronic pathologic disease. HCV and GBV-B are also closely phylogenetically related, and advances in characterization of the immune systems of New World primates have already led to the use of this model for drug testing and vaccine trials. Herein, we discuss the benefits and caveats of the GBV-B infection model and discuss potential avenues for future development of novel vaccines and immunotherapies.
Lopes, Ana Patrícia; Granada, Sara; Oliveira, Ana Cristina; Brancal, Hugo; Dubey, Jitender P; Cardoso, Luís; Vilhena, Hugo
Despite the worldwide importance of zoonotic parasite Toxoplasma gondii, nothing is known of toxoplasmosis in animals in Angola. The present study aimed at estimating the seroprevalence and also at assessing correlates of T. gondii infection in pet dogs from Luanda, Angola. Dogs (n = 103) brought to a veterinary clinic in the city of Luanda were investigated. Serum samples were tested for antibodies to T. gondii with a modified agglutination test (MAT) commercial kit, at serial dilutions of 1∶20 to 1∶160. In accordance with the established cutoff value (MAT ≧20), 16 dogs [15·5%; 95% confidence interval (CI): 9·2-24·0%] had antibodies to T. gondii: 10 had a titer of 20, two had a titer of 40, and four had a titer of 80. Age (≧12 months) was found to be a risk factor for infection [odds ratio (OR) = 9·23; 95% CI: 1·16-73·27). For each 1-year increase in age, the risk of a dog being found seropositive significantly increased by an OR of 1·18 (95% CI: 1·02-1·36). The present study, which represents the first serological survey of T. gondii in any animal species from Angola, reveals a 15·5% seroprevalence of infection in pet dogs in Luanda. Further studies are needed to better understand the epidemiology of zoonotic T. gondii infection in Luanda and also in Angola.
Zou, Rongrong; Zhang, Guoliang; Li, Shaoyuan; Wang, Wenfei; Yuan, Jing; Li, Jianming; Wang, Yanrong; Lin, Yimin; Deng, Yong; Zhou, Boping; Gao, George Fu; Liu, Yingxia
Enterovirus 71 (EV71), one of the major pathogens of Hand, foot and mouth disease (HFMD), results in millions of infections and hundreds of deaths each year in Southeast Asia. Biased infection and variable clinical manifestations of EV71 HFMD indicated that host genetic background played an important role in the occurrence and development of the disease. We identified the mRNA profiles of EV71 HFMD patients, which type I interferon (IFN) pathway related genes were down-regulated. Four single nucleotide polymorphisms (SNPs) of type I IFN receptor 1 (IFNAR1) were chosen to analyze their relationships to EV71 infection. We found that genotype GG of promoter variant rs2843710 was associated with the susceptibility and severity to EV71 HFMD. In addition, we assessed the regulatory effects of rs2843710 to IFN stimulated genes (ISGs), and found that the expressions of IFNAR1, OAS1 and MX1 were significantly lower in patients with rs2843710 genotype GG. And rs2843710 allele G showed weaker transcriptional activity compared with allele C. Our study indicated that rs2843710 of IFNAR1 was associated with the susceptibility and severity of EV71 HFMD in Chinese Han populations, acting as a functional polymorphism by regulating ISGs expression, such as OAS1 and MX1.
Kline, Kimberly A.; Schwartz, Drew J.; Gilbert, Nicole M.
Urinary tract infection (UTI) is most often caused by uropathogenic Escherichia coli (UPEC). UPEC inoculation into the female urinary tract (UT) can occur through physical activities that expose the UT to an inherently polymicrobial periurethral, vaginal, or gastrointestinal flora. We report that a common urogenital inhabitant and opportunistic pathogen, group B Streptococcus (GBS), when present at the time of UPEC exposure, undergoes rapid UPEC-dependent exclusion from the murine urinary tract, yet it influences acute UPEC-host interactions and alters host susceptibility to persistent outcomes of bladder and kidney infection. GBS presence results in increased UPEC titers in the bladder lumen during acute infection and reduced inflammatory responses of murine macrophages to live UPEC or purified lipopolysaccharide (LPS), phenotypes that require GBS mimicry of host sialic acid residues. Taken together, these studies suggest that despite low titers, the presence of GBS at the time of polymicrobial UT exposure may be an overlooked risk factor for chronic pyelonephritis and recurrent UTI in susceptible groups, even if it is outcompeted and thus absent by the time of diagnosis. PMID:22988014
Xing, Xuexia; Li, Xiaohui; Zhang, Mingzhen; Wang, Yuan; Liu, Bingyang; Xi, Qiliang; Zhao, Ke; Wu, Yunjie; Yang, Tiezhao
The root-knot nematode (RKN) Meloidogyne incognita reproduces on the roots of tobacco (Nicotiana tabacum), damaging crops, reducing crop yield, and causing economic losses annually. The development of resistant genotypes is an alternative strategy to effectively control these losses. However, the molecular mechanism responsible for host pathogenesis and defense responses in tobacco specifically against RKNs remain poorly understood. Here, root transcriptome analysis of resistant (Yuyan12) and susceptible (Changbohuang) tobacco varieties infected with RKNs was performed. Moreover, 2623 and 545 differentially expressed genes (DEGs) in RKN-infected roots were observed in Yuyan12 and Changbohuang, respectively, compared to those in non-infected roots, including 289 DEGs commonly expressed in the two genotypes. Among these DEGs, genes encoding cell wall modifying proteins, auxin-related proteins, the ROS scavenging system, and transcription factors involved in various biological and physiochemical processes were significantly expressed in both the resistant and susceptible genotypes. This work is thus the first report on the relationships in the RKN-tobacco interaction using transcriptome analysis, and the results provide important information on the mechanism of RKN resistance in tobacco. Copyright © 2016 Elsevier Inc. All rights reserved.
Full Text Available Background. The emergence of multidrug resistant bacterial pathogens in hospitals is becoming a challenge for surgeons to treat hospital acquired infections. Objective. To determine bacterial pathogens and drug susceptibility isolated from surgical site infections at St. Paul Specialized Hospital Millennium Medical College and Yekatit 12 Referral Hospital Medical College, Addis Ababa, Ethiopia. Methods. A cross-sectional study was conducted between October 2013 and March 2014 on 107 surgical site infected patients. Wound specimens were collected using sterile cotton swab and processed as per standard operative procedures in appropriate culture media; and susceptibility testing was done using Kirby-Bauer disc diffusion technique. The data were analyzed by using SPSS version 20. Result. From a total of 107 swabs collected, 90 (84.1% were culture positive and 104 organisms were isolated. E. coli (24 (23.1% was the most common organism isolated followed by multidrug resistant Acinetobacter species (23 (22.1%. More than 58 (75% of the Gram negative isolates showed multiple antibiotic resistance (resistance ≥ 5 drugs. Pan-antibiotic resistance was noted among 8 (34.8% Acinetobacter species and 3 (12.5% E. coli. This calls for abstinence from antibiotic abuse. Conclusion. Gram negative bacteria were the most important isolates accounting for 76 (73.1%. Ampicillin, amoxicillin, penicillin, cephazoline, and tetracycline showed resistance while gentamicin and ciprofloxacin were relatively effective antimicrobials.
Yao, Yanfeng; Bao, Linlin; Deng, Wei; Xu, Lili; Li, Fengdi; Lv, Qi; Yu, Pin; Chen, Ting; Xu, Yanfeng; Zhu, Hua; Yuan, Jing; Gu, Songzhi; Wei, Qiang; Chen, Honglin; Yuen, Kwok-Yung; Qin, Chuan
In 2012, a novel coronavirus (CoV) associated with severe respiratory disease, Middle East respiratory syndrome (MERS-CoV; previously known as human coronavirus-Erasmus Medical Center or hCoV-EMC), emerged in the Arabian Peninsula. To date, 114 human cases of MERS-CoV have been reported, with 54 fatalities. Animal models for MERS-CoV infection of humans are needed to elucidate MERS pathogenesis and to develop vaccines and antivirals. In this study, we developed rhesus macaques as a model for MERS-CoV using intratracheal inoculation. The infected monkeys showed clinical signs of disease, virus replication, histological lesions, and neutralizing antibody production, indicating that this monkey model is suitable for studies of MERS-CoV infection.
S R Motukupally
Full Text Available Purpose: To report clinical and microbiological profile of patients with ocular candidiasis. Materials and Methods: Patients with ocular candidiasis were retrospectively identified from microbiology records. Significant isolates of Candida species were identified by Vitek 2 compact system. Minimum inhibitory concentration (MIC of antifungal agents such as amphotericin B, itraconazole, voriconazole, fluconazole and caspofungin was determined by E test and of natamycin by microbroth dilution assay. Data on treatment and outcome were collected from medical records. Results: A total of 42 isolates of Candida were isolated from patients with keratitis-29, endophthalmitis-12 and orbital cellulitis-1. The most common species isolated was Candida albicans (12-keratitis, 4-endophthalmitis, 1-orbital cellulitis. All except one isolate were susceptible to amphotericin B. MIC of caspofungin was in the susceptible range in 28 (96.5% corneal isolates while 12 out of 29 (41.3% corneal isolates were sensitive to fluconazole. Resistance to voriconazole was seen in four corneal isolates. All isolates were susceptible to natamycin and all except two isolates were resistant or susceptible dose-dependent to itraconazole. Outcome of healed ulcer was achieved in 12/18 (66.6% patients treated medically, while surgical intervention was required in 11 patients. Among the isolates from endophthalmitis patients, 11/12 were susceptible to amphotericin B, 6/12 to voriconazole and all to natamycin. Ten out of 11 patients (one patient required evisceration with endophthalmitis were given intravitreal amphotericin B injection with variable outcome. Conclusions: Ocular candidiasis needs early and specific treatment for optimal results. Candida species continue to be susceptible to most commonly available antifungals including amphotericin B, voriconazole and natamycin.
Full Text Available Soybean cyst nematode (SCN; Heterodera glycines Ichinohe reproduces on the roots of common bean (Phaseolus vulgaris L. and can cause reductions in plant growth and seed yield. The molecular changes in common bean roots caused by SCN infection are unknown. Identification of genetic factors associated with SCN resistance could help in development of improved bean varieties with high SCN resistance. Gene expression profiling was conducted on common bean roots infected by SCN HG type 0 using next generation RNA sequencing technology. Two pinto bean genotypes, PI533561 and GTS-900, resistant and susceptible to SCN infection, respectively, were used as RNA sources eight days post inoculation. Total reads generated ranged between ~ 3.2 and 5.7 million per library and were mapped to the common bean reference genome. Approximately 70-90% of filtered RNA-seq reads uniquely mapped to the reference genome. In the inoculated roots of resistant genotype PI533561, a total of 353 genes were differentially expressed with 154 up-regulated genes and 199 down-regulated genes when compared to the transcriptome of non- inoculated roots. On the other hand, 990 genes were differentially expressed in SCN-inoculated roots of susceptible genotype GTS-900 with 406 up-regulated and 584 down-regulated genes when compared to non-inoculated roots. Genes encoding nucleotide-binding site leucine-rich repeat resistance (NLR proteins, WRKY transcription factors, pathogenesis-related (PR proteins and heat shock proteins involved in diverse biological processes were differentially expressed in both resistant and susceptible genotypes. Overall, suppression of the photosystem was observed in both the responses. Furthermore, RNA-seq results were validated through quantitative real time PCR. This is the first report describing genes/transcripts involved in SCN-common bean interaction and the results will have important implications for further characterization of SCN resistance genes in
Jain, Shalu; Chittem, Kishore; Brueggeman, Robert; Osorno, Juan M; Richards, Jonathan; Nelson, Berlin D
Soybean cyst nematode (SCN; Heterodera glycines Ichinohe) reproduces on the roots of common bean (Phaseolus vulgaris L.) and can cause reductions in plant growth and seed yield. The molecular changes in common bean roots caused by SCN infection are unknown. Identification of genetic factors associated with SCN resistance could help in development of improved bean varieties with high SCN resistance. Gene expression profiling was conducted on common bean roots infected by SCN HG type 0 using next generation RNA sequencing technology. Two pinto bean genotypes, PI533561 and GTS-900, resistant and susceptible to SCN infection, respectively, were used as RNA sources eight days post inoculation. Total reads generated ranged between ~ 3.2 and 5.7 million per library and were mapped to the common bean reference genome. Approximately 70-90% of filtered RNA-seq reads uniquely mapped to the reference genome. In the inoculated roots of resistant genotype PI533561, a total of 353 genes were differentially expressed with 154 up-regulated genes and 199 down-regulated genes when compared to the transcriptome of non- inoculated roots. On the other hand, 990 genes were differentially expressed in SCN-inoculated roots of susceptible genotype GTS-900 with 406 up-regulated and 584 down-regulated genes when compared to non-inoculated roots. Genes encoding nucleotide-binding site leucine-rich repeat resistance (NLR) proteins, WRKY transcription factors, pathogenesis-related (PR) proteins and heat shock proteins involved in diverse biological processes were differentially expressed in both resistant and susceptible genotypes. Overall, suppression of the photosystem was observed in both the responses. Furthermore, RNA-seq results were validated through quantitative real time PCR. This is the first report describing genes/transcripts involved in SCN-common bean interaction and the results will have important implications for further characterization of SCN resistance genes in common bean.
Gou, Q Y; Yu, R B; Shi, R H
Objective: To compare the efficacy and the risk of adverse effect of drug susceptibility test guided therapy and novel empirical quadruple therapy for Helicobacter (H.) pylori infection. Methods: Literature retrieval was conducted by using major databases. Related papers published up to June 2015 were considered eligible if they were randomized control trials comparing different pharmacological formulations for H. pylori infection and used in a network Meta-analysis and a single rate Meta-analysis to evaluate the relative and absolute rates of H. pylori eradication and the risk of adverse effect. The Jadad score was used to evaluate the methodological quality. Funnel plot was constructed to evaluate the risk of publication bias. Begg's rank correlation test or Egger's regression intercept test was done for the asymmetry of funnel plot. Results: Twenty randomized control trials for the treatment of 6 753 initial treated patients with H. pylori infection were included. Drug susceptibility test guided therapy was significantly superior to concomitant therapy, hybrid therapy, sequential therapy and bismuth quadruple therapy. The culture-based therapy had the highest likelihood of improving clinical efficacy, with lowest risk of adverse effect. Concomitant therapy had the highest probability of causing adverse effect despite its effectiveness. Hybrid therapy and bismuth quadruple therapy were associated with lower risk of adverse effect and higher effectiveness. Conclusion: Drug susceptibility test guided therapy showed superiority to other 4 interventions for H. pylori eradication mentioned above. Hybrid therapy and bismuth quadruple therapy might be applied in the settings where the culture-based strategy is not available.
Atan, Ozlem; Kucukcelebi, Ahmet; Atik, Tahir; Ozkınay, Ferda
There have been studies focused on mannose binding lectin (MBL) polymorphism and susceptibility to recurrent respiratory tract infections (RRTI) with inconclusive results. This present study is a meta-analysis of possible MBL and RRTI association in children. A literature search was performed using Medline and PubMed and abstracts were reviewed for relevance. Any study was considered to be eligible for inclusion if it met the following criteria: the MBL gene polymorphism at codon 54 was determined, the outcome was recurrent respiratory tract infection in children and there were at least two comparison groups. The odds ratios(OR) of the genetic MBL polymorphisms were combined and calculated, and the forest plots of the OR value distributions were drawn. Chi-squared testing of heterogeneity was done (prespiratory tract infection in children. Summary of the article's main point Here are discrepancies regarding the importance of MBL polymorphism and its impact on recurrent respiratory tract infections. Our meta analysis did not find statistically significant association between MBL codon 54 polymorphism and recurrent respiratory tract infection in children. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Mauck, Kerry E; De Moraes, Consuelo M; Mescher, Mark C
Plant viruses can profoundly alter the phenotypes of their host plants, with potentially far-reaching implications for ecology. Yet few studies have explored the indirect, host-mediated, effects of plant viruses on non-vector insects. We examined how infection of Cucurbita pepo plants by Cucumber mosaic virus (CMV) impacted the susceptibility of aphids (Myzus persicae) to attack by the parasitoid wasp Aphidius colemani. In semi-natural foraging assays, we observed higher rates of aphid parasitism on infected plants compared to healthy plants. Subsequent experiments revealed that this difference is not explained by different attack rates on plants differing in infection status, but rather by the fact that parasitoid larvae successfully complete their development more often when aphid hosts feed on infected plants. This suggests that the reduced nutritional quality of infected plants as host for aphids--documented in previous studies--compromises their ability to mount effective defenses against parasitism. Furthermore, our current findings indicate that the aphid diet during parasitoid development (rather than prior to wasp oviposition) is a key factor influencing resistance. These findings complement our previous work showing that CMV-induced changes in host plant chemistry alter patterns of aphid recruitment and dispersal in ways conducive to virus transmission.
Feldman, Charles; Anderson, Ronald
The predisposition of cigarette smokers for development of oral and respiratory infections caused by microbial pathogens is well recognised, with those infected with the human immunodeficiency virus (HIV) at particularly high risk. Smoking cigarettes has a suppressive effect on the protective functions of airway epithelium, alveolar macrophages, dendritic cells, natural killer (NK) cells and adaptive immune mechanisms, in the setting of chronic systemic activation of neutrophils. Cigarette smoke also has a direct effect on microbial pathogens to promote the likelihood of infective disease, specifically promotion of microbial virulence and antibiotic resistance. In addition to interactions between smoking and HIV infection, a number of specific infections/clinical syndromes have been associated epidemiologically with cigarette smoking, including those of the upper and lower respiratory tract, gastrointestinal tract, central nervous and other organ systems. Smoking cessation benefits patients in many ways, including reduction of the risk of infectious disease. Copyright © 2013 The British Infection Association. Published by Elsevier Ltd. All rights reserved.
In vitro encystment of Himasthla elongata cercariae (Digenea, Echinostomatidae) in the haemolymph of blue mussels Mytilus edulis as a tool for assessing cercarial infectivity and molluscan susceptibility.
Levakin, I A; Losev, E A; Nikolaev, K E; Galaktionov, K V
Infectivity of Himasthla elongata cercariae to mussels, their second intermediate hosts, and resistance by these hosts to infection were assessed on the basis of the cercariae's ability to encyst in mussel haemolymph in vitro. A series of experimental in vivo infections of mussels with batches of cercariae, each batch released from a different single infected mollusc and referred to as a clone (due to their shared genotype), demonstrated that the results of the in vitro tests corresponded to the actual indices of infectivity/susceptibility of the parasites and their hosts. Most cercarial clones had high infectivity, with a few clones having very high or, at the other extreme, very low infectivity. A similar pattern was revealed in mussel resistance to cercarial infection. Most of the molluscs tested were moderately susceptible to cercarial infection, but at each extreme a small fraction (less than 10%) displayed very high or very low susceptibility. It was shown that there were no totally compatible or totally incompatible 'cercaria clone/mussel' combinations. Results obtained are compared with the data on intra-population variability using the characters parasite infectivity/host compatibility for trematode/mollusc-first intermediate host associations. Results are made relevant to actual infection levels in mussel settlements at the White Sea.
Szymańska-Czerwińska, Monika; Galińska, Elżbieta Monika; Niemczuk, Krzysztof; Knap, Józef Piotr
Coxiella burnetii is the etiological agent of Q fever, and outbreaks of Q fever have been reported in different parts of Europe both in animals and humans. Human infections are mostly associated with infections in ruminants, e.g., sheep, goats, and cows. Various professional groups are occupationally exposed to infection with C. burnetii. The aim of this study was investigate the prevalence of C. burnetii in farm workers. Serum samples were collected from 151 persons from six different regions of Poland. The serum samples were tested using three serological methods--complement fixation test (CFT), enzyme-linked immunosorbent assay (ELISA), and indirect fluorescent antibody (IFA). A total of 71 samples of blood were also tested by real-time PCR. The results showed that antibodies against C. burnetii were present in the tested sera. Average percentages of seropositive samples in IFA, ELISA, and CFT were 31.12%, 39.07%, and 15.23%, respectively. Positive results were noted in each testing center. Of the three test types, IFA results were considered the most sensitive. Real-time PCR confirmed the presence of DNA specific for C. burnetii in 10 patients. The farming workforce constitutes an occupational risk group with an increased risk for C. burnetii infection, presumably because of their contact with infected livestock.
Vanrompay, Daisy; Hoang, Thi Q T; De Vos, Liselotte; Verminnen, Kristel; Harkinezhad, Taher; Chiers, Koen; Morré, Servaas A; Cox, Eric
The purpose of the present study was to evaluate pigs as a large-animal model for female genital infection with two Chlamydia trachomatis human serovar E strains. Sixteen-week-old specific-pathogen-free female pigs (gilts) were intravaginally infected with the trachoma type E reference strain Bour or the urogenital serovar E strain 468. Several conclusions can be drawn from our findings on the pathogenicity of a primary C. trachomatis genital infection in gilts. First of all, we demonstrated that the serovar E strains Bour and 468 could ascend in the genital tract of gilts. The serovar E strains could replicate in the superficial columnar cervical epithelium and in the superficial epithelial layer of the uterus, which are known to be the specific target sites for a C. trachomatis genital infection in women. Second, inflammation and pathology occurred at the replication sites. Third, the organisms could trigger a humoral immune response, as demonstrated by the presence of immunoglobulin M (IgM), IgG, and IgA in both serum and genital secretion samples. Our findings imply that the pig model might be useful for studying the pathology, pathogenesis, and immune response to a C. trachomatis infection of the genital system.
Sánchez, Elena G; Riera, Elena; Nogal, Marisa; Gallardo, Carmina; Fernández, Paloma; Bello-Morales, Raquel; López-Guerrero, José Antonio; Chitko-McKown, Carol G; Richt, Jürgen A; Revilla, Yolanda
African swine fever virus (ASFV) is a highly pathogenic, double-stranded DNA virus with a marked tropism for cells of the monocyte-macrophage lineage, affecting swine species and provoking severe economic losses and health threats. In the present study, four established porcine cell lines, IPAM-WT, IPAM-CD163, C∆2+ and WSL, were compared to porcine alveolar macrophage (PAM) in terms of surface marker phenotype, susceptibility to ASFV infection and virus production. The virulent ASFV Armenia/07, E70 or the naturally attenuated NHV/P68 strains were used as viral models. Cells expressed only low levels of specific receptors linked to the monocyte/macrophage lineage, with low levels of infection overall, with the exception of WSL, which showed more efficient production of strain NHV/P68 but not of strains E70 and Armenia/07.
Candida albicans is a commensal microorganism in the mucosa of healthy individuals, but is also the most common opportunistic fungal pathogen of humans. It causes from benign infections such as oral and vaginal candidiasis to fatal, systematic diseases in immunocompromised or critically ill patients. In addition to improved therapy, the rapid and accurate identification of the disease-causing strains is crucial for diagnosis, clinical treatment and epidemiological studies of candidiasis. A variety of methods for strain typing of C. albicans have been developed. The most commonly used methods with the focus on recently developed molecular typing or DNA-fingerprinting strategies and the recent findings in the association of specific and genetically similar genotypes with certain infection types and the correlation between azole susceptibilities and certain genotypes of C. albicans from China are reviewed. PMID:24772369
Hamza, O.J.M.; Matee, M.I.N.; Moshi, M.J.; Simon, E.N.; Mugusi, F.; Mikx, F.H.M.; Palenstein Helderman, W.H. van; Rijs, A.J.M.M.; Ven, A.J.A.M. van der; Verweij, P.E.
BACKGROUND: In Tanzania, little is known on the species distribution and antifungal susceptibility profiles of yeast isolates from HIV-infected patients with primary and recurrent oropharyngeal candidiasis. METHODS: A total of 296 clinical oral yeasts were isolated from 292 HIV-infected patients
Gómez-Morales, Maria Angeles; Selmi, Marco; Ludovisi, Alessandra; Amati, Marco; Fiorentino, Eleonora; Breviglieri, Lorenzo; Poglayen, Giovanni; Pozio, Edoardo
Nematode parasites of the genus Trichinella are important foodborne pathogens transmitted by ingestion of striated muscles harbouring infective larvae. Wild carnivorous and omnivorous animals are the most important reservoirs of these parasites. Hunting activities play an important role in Trichinella spp. The aim of the present work was to assess if serological detection of anti-Trichinella IgG in hunting dogs can be a tool to indirectly monitor Trichinella spp. infections in wildlife. An ELISA and a Western blot (Wb) were developed and validated. To validate the assays, serum samples were collected from 598 dogs considered to be Trichinella-free, 15 naturally infected dogs, and six experimentally infected foxes. Sera were tested by ELISA with Trichinella spiralis excretory/secretory antigens. The diagnostic sensitivity and specificity of ELISA were 100 % (95 % CI: 83.89-100 %) and 95.65 % (95 % CI: 93.69-97.14 %), respectively. Sera from Trichinella-infected dogs/foxes tested by Wb showed a three-band pattern ranging from 48 to 72 kDa. Since the prevalence of Toxocara canis is very high in dogs, the specificity of the ELISA and Wb was further assessed by testing sera for anti-T. canis IgG using T. canis excretory/secretory antigens. No cross-reactivity was observed. To evaluate the test's reliability in the field, serum samples were collected from wild boar hunting dogs from Central Italy where Trichinella britovi was circulating among wildlife. Out of 384 hunting dog sera, 189 (49.2 %) tested positive by ELISA and of these, 56 (29.6 %) tested positive by Wb, showing an overall prevalence of 14.6 % (56/384) in the wild boar hunting dog population of the investigated area. The serological prevalence in hunting dogs was significantly (P Trichinella spp. among wildlife can be monitored by testing sera from hunting dogs, which could act as sentinel animals of Trichinella spp. circulation in wildlife.
Full Text Available BACKGROUND: Although several studies have investigated whether CCL3L1 copy number variation (CNV influences the risk of HIV-1 infection, there are still no clear conclusions. Therefore, we performed a meta-analysis using two models to generate a more robust estimate of the association between CCL3L1 CNV and susceptibility to HIV-1 infection. METHODS: We divided the cases and controls into two parts as individuals with CCL3L1 gene copy number (GCN above the population specific median copy number (PMN and individuals with CCL3L1 GCN below PMN, respectively. Odds ratios (ORs with 95% confidence intervals (95% CIs were given for the main analysis. We also conducted stratified analyses by ethnicity, age group and sample size. Relevant literatures were searched through PubMed and ISI Web of Knowledge up to March 2010. RESULTS: In total, 9 studies with 2434 cases and 4029 controls were included. ORs for the main analysis were 1.35 (95% CI, 1.02-1.78, model: GCN ≤ PMN Vs. GCN > PMN and 1.70 (95% CI, 1.30-2.23, model: GCN < PMN Vs. GCN ≥ PMN, respectively. Either in stratified analysis, statistically significant results can be detected in some subgroups. CONCLUSIONS: Our analyses indicate that CCL3L1 CNV is associated with susceptibility to HIV-1 infection. A lower copy number is associated with an increased risk of HIV-1 infection, while a higher copy number is associated with reduced risk for acquiring HIV-1.
Full Text Available Introduction: Uropathogenic Escherichia coli (UPEC rely on the correlation of virulence expression with antimicrobial resistance to persist and cause severe urinary tract infections (UTIs. Objectives: We assessed the virulence pattern and prevalence among UPEC strains susceptible and resistant to multiple antimicrobial classes. Methods: A total of 174 non-duplicate UPEC strains from patients with clinically significant UTIs were analysed for susceptibility to aminoglycoside, antifolate, cephalosporin, nitrofuran and quinolone antibiotics for the production of extended-spectrum β-lactamases and for the presence of six virulence determinants encoding adhesins (afimbrial, Type 1 fimbriae, P and S-fimbriae and toxins (cytotoxic necrotising factor and haemolysin. Results: Relatively high resistance rates to nalidixic acid, ciprofloxacin, cephalothin and trimethoprim-sulfamethoxazole (82%, 78%, 62% and 59%, respectively were observed. Fourteen distinct patterns were identified for the virulence determinants such as afaBC, cnfI, fimH, hylA, papEF and sfaDE. The toxin gene, cnfI (75.3%, was the second most prevalent marker to the adhesin, fimH (97.1%. The significant association of sfaDE/hylA (P < 0.01 among antimicrobial resistant and susceptible strains was also observed notwithstanding an overall greater occurrence of virulence factors among the latter. Conclusions: This study provides a snapshot of UPEC complexity in Jamaica and highlights the significant clonal heterogeneity among strains. Such outcomes emphasise the need for evidence-based strategies in the effective management and control of UTIs.
Adriane Holtz Tirabassi
Full Text Available The widespread occurrence of anthelmintic-resistant gastrointestinal nematodes (GINs, particularly Haemonchus contortus, in sheep production systems has magnified the need to identify and develop alternative control strategies. Strategies include the selection of genetically GIN-resistant sheep and the implementation of biological parasite control to reduce dependence on anthelmintic drugs. In this study, we aimed to establish the molecular identity of bacterial communities present in the abomasum of sheep classified as resistant or susceptible to H. contortus, an abomasal parasite. Thirty-eight sheep were experimentally infected with L3 Haemonchus contortus and analyzed for fecal egg count (FEC and hematocrit (Ht to establish haemonchosis resistance or susceptibility. Four resistant sheep (RS and four susceptible sheep (SS were selected for microbial sampling and subsequent phylogenetic analysis. Molecular identification of the bacteria was based on amplification of the bacterial 16S rRNA gene, construction of a 16S rDNA clone library, and subsequent gene sequencing. Significant differences (p = 0.05 were observed in the occurrence of different phyla identified in RS and SS libraries: Firmicutes (61.4% and 37.2%, respectively, Proteobacteria (10.2% and 37.2%, respectively, Bacteroidetes (12.8% and 5.8%, respectively, and unclassified bacteria (12.8% and 17%, respectively. Differences between the proportions of bacterial communities present in the RS and SS pool samples were observed, contributing as a first step toward the assessment of the association between the gastrointestinal tract microbiota and nematode resistance in sheep.
Leon Rodriguez, Daniel A; Acosta-Herrera, Marialbert; Carmona, F David; Dolade, Nuria; Vargas, Sofia; Echeverría, Luis Eduardo; González, Clara Isabel; Martin, Javier
Tyrosine kinase 2 (TYK2) is a member of the Janus kinases family implicated in the signal transduction of type I interferons and several interleukins. It has been described that genetic mutations within TYK2 lead to multiple deleterious effects in the immune response. In this work, we have analyzed three functional independent variants from the frequency spectrum on the TYK2 gene (common and low-frequency variants) suggested to reduce the function of the gene in mediating cytokine signaling and the susceptibility to infections by Trypanosoma cruzi and/or the development of Chagas cardiomyopathy in the Colombian population. A total of 1,323 individuals from a Colombian endemic region for Chagas disease were enrolled in the study. They were classified as seronegative (n = 445), seropositive asymptomatic (n = 336), and chronic Chagas Cardiomyopathy subjects (n = 542). DNA samples were genotyped using TaqMan probes. Our results showed no statistically significant differences between the allelic frequencies of the three analyzed variants when seropositive and seronegative individuals were compared, therefore these variants were not associated with susceptibility to Chagas disease. Moreover, when Chagas cardiomyopathy patients were compared to asymptomatic patients, no significant associations were found. Previous reports highlighted the association of this gene in immune-related disorders under an autoimmunity context, but not predisposing patients to infectious diseases, which is consistent with our findings. Therefore, according to our results, TYK2 gene variants do not seem to play an important role in Chagas disease susceptibility and/or chronic Chagas cardiomyopathy.
Iversen, Marie Beck; Jensen, Simon Kok; Hansen, Anne Louise
that received local pre-treatment with αGalCer prior to intra-vaginal HSV-2 infection had a lower mean disease score, mortality and viral load in the vagina following infection, compared to mice that did not receive αGalCer pre-treatment. Further, we found increased numbers of CD45 and NK1.1 positive cells...
Elks, Philip M.; Brizee, Sabrina; van der Vaart, Michiel; Walmsley, Sarah R.; van Eeden, Fredericus J.; Renshaw, Stephen A.; Meijer, Annemarie H.
Tuberculosis is a current major world-health problem, exacerbated by the causative pathogen, Mycobacterium tuberculosis (Mtb), becoming increasingly resistant to conventional antibiotic treatment. Mtb is able to counteract the bactericidal mechanisms of leukocytes to survive intracellularly and develop a niche permissive for proliferation and dissemination. Understanding of the pathogenesis of mycobacterial infections such as tuberculosis (TB) remains limited, especially for early infection a...
Rit, Kalidas; Saha, Rajdeep
Antibiotic-resistant Acinetobacter nosocomial infection is a leading problem. It acts as an opportunistic pathogen to cause a wide spectrum of infection including nosocomial pneumonia, meningitis, endocarditis, skin and soft tissue infections, urinary tract infection, conjunctivitis, burn wound infection and bacteremia. Multidrug-resistant Acinetobacter infection creates a great problem in hospital setting. The clinical specimens obtained from ICU and different surgical and medical wards were investigated using standard microbiological techniques to know the distribution of and their resistant profile. Antimicrobial resistance was studied using the modified Kirby Bauer disk diffusion technique following the CLSI protocol. Major infections found in different medical wards, surgical wards and ICU were due to Acinetobacter baumannii (74.02%), A. lowfii (14.2%), A. haemolyticus (7.79%), A. junii (3.8%) among Acinetobacter spices. Acinetobacter showed increased resistant against majority of commercially available drugs imipenem (5.2%), meropenem (9.75%), piperacillin-tazobactum (18.2%), netilmicin (16.24%), amikacin (14.29%), ceftazidime (74.1%), gentamicin (70.13%), ofloxacin (42.21%). A. baumannii was found to be associated with UTI, RTI, septicemia, bacteremia, and meningitis and wound infection. A. baumannii displayed higher resistance to more number of antibiotics than other nosocomial pathogens from ICU.
Conclusion: By evaluating the infectious agents during the period of the study, it was found that due to the focus on treatment of Gram negative bacteria, Gram positive bacteria especially Staphylococcus aureus and Coagulase Negative Staphylococcus have at least doubled. This increase in two important nosocomial infections is a next threat of infection and septicemia for burn victims.
Reports of bovine viral diarrhea virus (BVDV) infections in alpacas have been increasing over the past several years but much is still unknown about the mechanisms of disease in this species. This report describes research performed to characterize the transmission of BVDV from persistently infected...
Paul B. Tchounwou
Full Text Available Human health is a major concern when considering the disposal of large quantities of animal waste. Health concerns could arise from exposure to pathogens and excess nitrogen associated with this form of pollution. The objective was to collect and analyze health data related to selected bacterial infections associated with the use of animal waste in Louisiana. An analysis of adverse health effects has been conducted based on the incidence/prevalence rates of campylobacteriosis, E. coli O157:H7 infection, salmonellosis and shigellosis. The number of reported cases increased during the summer months. Analysis of health data showed that reported disease cases of E. coli O157:H7 were highest among Caucasian infants in the 0-4 year old age category and in Caucasian children in the 5-9 year old age category. Fatalities resulting from salmonellosis are low and increases sharply with age. The number of reported cases of shigellosis was found to be higher in African American males and females than in Caucasians. The high rate of identification in the younger population may result from the prompt seeking of medical care, as well as the frequent ordering of stool examination when symptoms become evident among this group of the population. The association with increasing age and fatality due to salmonellosis could be attributed to declining health and weaker immune systems often found in the older population. It is concluded that both animal waste and non-point source pollution may have a significant impact on human health.
Full Text Available This study was conducted to determine seroprevalence of Neospora infection in cattle, sheep, horses, donkeys, and dogs in Hamedan province, Iran. Blood samples (n=2254 from the animals were collected randomly during 2009 to 2012. Sera were prepared from the collected blood samples, which were then examined for the presence of antibodies against Neospora using enzyme-linked immunosorbent assay (ELISA, Neospora modified direct agglutination test (N-MAT, and indirect fluorescent antibody test (IFAT. The seroprevalence rates of Neospora were found as 17.4% (n=245/1406 in cattle, 2.2% (n=8/358 in sheep, 40.8% (n=49/120 in horses, 52% (n=52/100 in donkeys, and 27% (n=73/270 in dogs. In this study, higher levels of Neospora infection were detected in cattle, horses, donkeys, and dogs. This is the first comprehensive study of Neospora infection in domestic animals in Iran. Further researches on molecular and bioassay studies and designing appropriate control strategies against neosporosis in Iran are necessary and strongly recommended.
Yauri, Verónica; Castro-Sesquen, Yagahira E.; Verastegui, Manuela; Angulo, Noelia; Recuenco, Fernando; Cabello, Ines; Malaga, Edith; Bern, Caryn; Gavidia, Cesar M.; Gilman, Robert H.
Pigs were infected with a Bolivian strain of Trypanosoma cruzi (genotype I) and evaluated up to 150 days postinoculation (dpi) to determine the use of pigs as an animal model of Chagas disease. Parasitemia was observed in the infected pigs during the acute phase (15–40 dpi). Anti-T.cruzi immunoglobulin M was detected during 15–75 dpi; high levels of anti-T.cruzi immunoglobulin G were detected in all infected pigs from 75 to 150 dpi. Parasitic DNA was observed by western blot (58%, 28/48) and polymerase chain reaction (27%, 13/48) in urine samples, and in the brain (75%, 3/4), spleen (50%, 2/4), and duodenum (25%, 1/4), but no parasitic DNA was found in the heart, colon, and kidney. Parasites were not observed microscopically in tissues samples, but mild inflammation, vasculitis, and congestion was observed in heart, brain, kidney, and spleen. This pig model was useful for the standardization of the urine test because of the higher volume that can be obtained as compared with other small animal models. However, further experiments are required to observe pathological changes characteristic of Chagas disease in humans. PMID:26928841
Characterization of Antimicrobial Susceptibility and Its Association with Virulence Genes Related to Adherence, Invasion, and Cytotoxicity in Campylobacter jejuni and Campylobacter coli Isolates from Animals, Meat, and Humans.
Lapierre, Lisette; Gatica, María A; Riquelme, Víctor; Vergara, Constanza; Yañez, José Manuel; San Martín, Betty; Sáenz, Leonardo; Vidal, Maricel; Martínez, María Cristina; Araya, Pamela; Flores, Roberto; Duery, Oscar; Vidal, Roberto
The aim of this research was to statistically analyze the association between antimicrobial susceptibility/resistance to erythromycine, gentamicin, ciprofloxacin, and tetracycline and 11 virulence genes associated with adherence, invasion, and cytotoxicity in 528 isolates of Campylobacter coli and Campylobacter jejuni obtained from retail meat and fecal samples from food-producing animals and human patients. A high percentage of Campylobacter strains were resistant to antimicrobials, specifically ciprofloxacin and tetracycline. Moreover, we observed a wide distribution of virulence genes within the analyzed strains. C. jejuni strains were more susceptible to antimicrobials, and showed greater number of virulence genes than C. coli strains. Genes related to invasion capability, such as racR, ciaB, and pldA, were associated with antimicrobial-susceptible strains in both species. The genes cdtA and dnaJ, a citotoxin unit and an adherence-related gene, respectively, were associated with antimicrobial-resistant strains in both species. In conclusion, Campylobacter strains show a statistically significant association between antimicrobial susceptibility and the presence of virulence genes.
Debourgogne, Anne; Dorin, Joséphine; Machouart, Marie
Over the last few decades, the number of patients susceptible to invasive filamentous fungal infections has steadily increased, especially in populations suffering from hematological diseases. The pathogens responsible for such mycoses are now quite well characterized, such as Aspergillus spp. - the most commonly isolated mold -, Mucorales, Fusarium spp., Scedosporium spp. or melanized fungi. An increase in the incidence of this category of 'emerging' fungi has been recently highlighted, evoking a shift in fungal ecology. Starting from these medical findings, taking a step back and adopt a wider perspective offers possible explanations of this phenomenon on an even larger scale than previously reported. In this review, we illustrate the link between emerging fungi in medicine and changes in ecology or human behaviours, and we encourage integrative approaches to apprehend the adverse effects of progress and develop preventive measures in vast domains, such as agriculture or medicine. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.
Carryl, Heather; Swang, Melanie; Lawrence, Jerome; Curtis, Kimberly; Kamboj, Herman; Van Rompay, Koen K. A.; De Paris, Kristina; Burke, Mark W.
Pediatric human immunodeficiency virus (HIV-1) infection remains a global health crisis. Children are much more susceptible to HIV-1 neurological impairments than adults, which can be exacerbated by coinfections. Neurological characteristics of pediatric HIV-1 infection suggest dysfunction in the frontal cortex as well as the hippocampus; limited MRI data indicate global cerebral atrophy, and pathological data suggest accelerated neuronal apoptosis in the cortex. An obstacle to pediatric HIV-...
Sun, Wei; Su, Jianrong; Xu, Shuzhen; Yan, Donghui
Trichosporon asahii is the causative agent of both superficial and deep-seated infections of increasing morbidity and mortality. Urinary tract infections (UTIs) due to T. asahii, frequently associated with indwelling medical devices, have been reported over the years. However, few studies have specifically focused on the genotypic diversity of T. asahii isolates from urine specimens from intensive care units (ICUs), let alone potential virulence factors and antifungal susceptibility testing. In the present study, 23 T. asahii isolates were collected from UTI patients in ICUs between January 2008 and January 2012. Three genotypes (I, III, IV) were determined based on the combination of internal transcribed spacer and intergenic spacer locus PCR. Protease, phospholipase and haemolysin production was assessed by halo formation on corresponding agar plates. Only haemolytic activity was observed to varying degrees. Neither protease nor phospholipase was detectable. Biofilm formation on polystyrene surfaces was detected through a formazan salt reduction assay. All clinical isolates had the ability to form biofilm. In contrast to the susceptibility of planktonic T. asahii cells to clinically used amphotericin B, 5-flucytosine, fluconazole, itraconazole and voriconazole, a remarkable rise in the MICs of these for biofilm T. asahii cells was observed. Our results suggested that genotype IV was the most prevalent genotype among T. asahii isolates from ICUs in China. Haemolysin and biofilm might contribute to the pathogenicity and recurrence of T. asahii-related UTIs. Although triazoles, especially voriconazole, were effective against planktonic T. asahii cells, they failed to treat preformed biofilms.
Spoustová, Petra; Hýsková, Veronika; Müller, Karel; Schnablová, Renata; Ryšlavá, Helena; Čeřovská, Noemi; Malbeck, Jiří; Cvikrová, Milena; Synková, Helena
Faster or stronger response to pathogen occurs if plants undergo prior priming. Cytokinins seem to be also involved in plant priming and in response to pathogens. Susceptibility to Potato virus Y(NTN) (PVY(NTN)) was studied in transgenic cytokinin overproducing (Pssu-ipt) tobacco and compared with nontransgenic plants. Since cytokinin overproduction inhibits development of plant roots and grafting overcomes this limitation, both types were grown as rooted and/or grafted plants to check also the effect of grafting. Control rooted tobacco (C), the most susceptible to PVY(NTN), showed always symptoms during the infection together with the rising virus content and a systemic response, such as accumulation of H2O2, salicylic acid (SA) and other phenolic acids, and stress-induced enzyme activities. In transgenic and grafted plants, the response to PVY(NTN) was dependent on protective mechanisms activated prior to the inoculation. In Pssu-ipt tobacco, cytokinin active forms and SA contents exceeded manifold their content in C. Grafting promoted the accumulation of phenolics, but SA, and stimulated peroxidase activities. Thus, the pre-infection barrier established in both transgenic and grafted plants helped to suppress partly the virus multiplication and resulted in milder symptom development. However, only the synergic effect of both grafting and the high cytokinins led to PVY(NTN) tolerance in transgenic grafts. Possible mechanisms were discussed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Yangco, B G; TeStrake, D; Okafor, J
A dematiaceous fungus, Phialophora richardsiae (Nannf.) Conant, was isolated from human bone. In culture the fungus produced no yeast forms and was less pigmented than two other P. richardsiae isolates. While growth rates were similar, colonial forms differed. Phialides were of two kinds. While both had broad bases and tapered at the tips, only one terminated with a cupulate or rarely a saucer-shaped collarette. Most phialides were hyaline with a few lightly pigmented ones in older cultures. Broth dilution susceptibility testing of the isolates against amphotericin B, miconazole, ketoconazole, clotrimazole, and 5-fluorocytosine showed the fungus was susceptible to miconazole, ketoconazole and amphotericin B at achievable serum levels and resistant to 5-fluorocytosine and clotrimazole. The other isolates were reported to differ in their resistance to miconazole and amphotericin B. Enzyme and salinity studies showed minor difference among the isolates.
Garg, Harsh; Li, Hua; Sivasithamparam, Krishnapillai; Kuo, John; Barbetti, Martin J.
Background and Aims Sclerotinia sclerotiorum can attack >400 plant species worldwide. Very few studies have investigated host–pathogen interactions at the plant surface and cellular level in resistant genotypes of oilseed rape/canola (Brassica napus). Methods Infection processes of S. sclerotiorum were examined on two B. napus genotypes, one resistant cultivar ‘Charlton’ and one susceptible ‘RQ001-02M2’ by light and scanning electron microscopy from 2 h to 8 d post-inoculation (dpi). Key Results The resistant ‘Charlton’ impeded fungal growth at 1, 2 and 3 dpi, suppressed formation of appresoria and infection cushions, caused extrusion of protoplast from hyphal cells and produced a hypersensitive reaction. At 8 dpi, whilst in ‘Charlton’ pathogen invasion was mainly confined to the upper epidermis, in the susceptible ‘RQ001-02M2’, colonization up to the spongy mesophyll cells was evident. Calcium oxalate crystals were found in the upper epidermis and in palisade cells in susceptible ‘RQ001-02M2’ at 6 dpi, and throughout leaf tissues at 8 dpi. In resistant ‘Charlton’, crystals were not observed at 6 dpi, whereas at 8 dpi they were mainly confined to the upper epidermis. Starch deposits were also more prevalent in ‘RQ001-02M2’. Conclusions This study demonstrates for the first time at the cellular level that resistance to S. sclerotiorum in B. napus is a result of retardation of pathogen development, both on the plant surface and within host tissues. The resistance mechanisms identified in this study will be useful for engineering disease-resistant genotypes and for developing markers for screening for resistance against this pathogen. PMID:20929899
Radha Rani D
Full Text Available Background: Bacterial bloodstream infections are important causes of morbidity and mortality globally. The aim of the present study was to determine the bacterial profile of bloodstream infections and their antibiotic susceptibility pattern among the clinically diagnosed cases of sepsis in cancer patients. Methods: In the present study, etiological and antimicrobial susceptibility profile of blood cultures over a period of 1 year at a tertiary cancer care hospital was done. Blood culture positive isolates were identified using standard microbiological methods and by Fully automated BD Phoenix 100. The antibiotic susceptibility pattern of the organisms was performed by Kirby-Bauer disc diffusion method and MIC (Minimum inhibitory concentration was done by Fully automated BD Phoenix 100. Results: There were 1178 blood culture samples, of which 327 (27.7% were identified to be culture positive. Out of 327 positive cultures, 299 (91.4% showed bacterial growth, Gram negative were 161 (53.8% and Gram positive were 138 (46.1%. Candida species were isolated from 13 (3.97% of positive samples and 15 samples showed contamination. The most common Gram-negative isolate was. Escherichia coli (37.80% and Gram-positive isolate was coagulasenegative staphylococci (52.80%. Escherichia coli showed highest sensitivity to amikacin (83.60% and sensitivity to piperacillin+ tazobactum and cefaperazone+sulbactam was 54.09% and 52.45% respectively. High degree of resistance was found to cephalosporins and levofloxacin. Conclusion: The results indicate high level of antimicrobial resistance among Gram negative bacilli in septicemic patients. The results warrant continuous monitoring of antimicrobial pattern so as to build geographical epidemiological data.
Resende, Sarah Stela; Milagres, Vanessa Gonçalves; Chaves, Daniel Gonçalves; Fontes, Cor Jesus Fernandes; Carvalho, Luzia Helena; Sousa, Tais Nobrega; Brito, Cristiana Ferreira Alves de
Plasmodium vivax has been reported to cause severe malaria, and one of the main resulting complications is anemia. Considering that P. vivax infects only young erythrocytes, anemia has been associated with the destruction of infected and non-infected erythrocytes. However, few studies have focused on understanding the relationship between the pathogenesis of P. vivax malaria and human genetic polymorphisms. Although ABO groups seem to influence the outcome of Plasmodium falciparum malaria, the association between P. vivax and ABO blood groups has been minimally investigated. Thus, we investigate the correlation between ABO blood groups and anemia induced by P. vivax infection. Five single nucleotide polymorphisms at the ABO gene were genotyped by PCR-RFLP and Real-Time PCR in P. vivax-infected subjects. The ABO blood types were associated with the hematological data of the patients. Our main finding was that type O infected-individuals showed lower levels of hemoglobin and hematocrit compared to type A-infected individuals. The correlation between ABO blood groups and hemoglobin levels remained significant when a multiple linear regression was applied with the possible confounding effects of clinical-epidemiologic variables taken into account. The finding that type O individuals have a higher frequency of anemia is a first step to understand the mechanisms involved in malaria anemia, which could be associated to increased destruction of type O erythrocytes. Copyright © 2017 Elsevier B.V. All rights reserved.
Ga Eun Park
Conclusions: These data suggest that tigecycline non-susceptible Acinetobacter spp have emerged and disseminated in the hospital in association with a recent exposure to carbapenems and an immunosuppressed state. This indicates that the rational use of antibiotics through a comprehensive antimicrobial stewardship program, especially in immunosuppressed patients, may be essential in limiting the emergence and spread of multidrug-resistant organisms such as tigecycline-resistant Acinetobacter spp, which are difficult to treat.
Higgins, D.A.; Kung, I.T.; Or, R.S.
Badger lungs contain dark granular foci (0.2 to 2.0 mm) comprising aggregates of enlarged macrophages containing birefringent crystalline particles. Particles were examined from the lungs of three badgers; many were silicates and a significant number were pure silica (SiO/sub 2/). The particles and the accompanying pathology resembled mixed dust fibrosis and silicosis in humans, diseases associated with increased susceptibility to tuberculosis.
Manuja, Balvinder K; Manuja, Anju; Dahiya, Rajni; Singh, Sandeep; Sharma, R C; Gahlot, S K
Equine influenza (EI) is primarily an infection of the upper respiratory tract and is one of the major infectious respiratory diseases of economic importance in equines. Re-emergence of the disease, species jumping by H3N8 virus in canines and possible threat of human pandemic due to the unpredictable nature of the virus have necessitated research on devising strategies for preventing the disease. The myxovirus resistance protein (Mx) has been reported to confer resistance to Orthomyxo virus infection by modifying cellular functions needed along the viral replication pathway. Polymorphisms and differential antiviral activities of Mx gene have been reported in pigs and chicken. Here we report the diversity of Mx gene, its expression in response to stimulation with interferon (IFN) α/β and their association with EI resistance and susceptibility in Marwari horses. Blood samples were collected from horses declared positive for equine influenza and in contact animals with a history of no clinical signs. Mx gene was amplified by reverse transcription from total RNA isolated from peripheral blood mononuclear cells (PBMCs) stimulated with IFN α/β using gene specific primers. The amplified gene products from representative samples were cloned and sequenced. Nucleotide sequences and deduced amino acid sequences were analyzed. Out of a total 24 amino acids substitutions sorting intolerant from tolerant (SIFT) analysis predicted 13 substitutions with functional consequences. Five substitutions (V67A, W123L, E346Y, N347Y, S689N) were observed only in resistant animals. Evolutionary distances based on nucleotide sequences with in equines ranged between 0.3-2.0% and 20-24% with other species. On phylogenetic analysis all equine sequences clustered together while other species formed separate clades. Copyright © 2014 Elsevier B.V. All rights reserved.
Wisplinghoff, Hilmar; Ebbers, Jenny; Geurtz, Lea; Stefanik, Danuta; Major, Yvette; Edmond, Michael B; Wenzel, Richard P; Seifert, Harald
Candida spp. are among the most frequent nosocomial pathogens, contributing significantly to morbidity and mortality. Longitudinal data on the epidemiology of Candida bloodstream infections (BSIs) are still limited. Isolates and clinical data from 1218 episodes of Candida BSI were prospectively collected from patients in 52 hospitals in the USA between 1998 and 2006. Susceptibilities to amphotericin B, flucytosine, fluconazole, posaconazole, voriconazole, anidulafungin, caspofungin and micafungin were determined for 1077 Candida isolates by the CLSI reference broth microdilution method using the recently published species-specific clinical breakpoints. Candida albicans was the most prevalent species (50.7%), followed by Candida parapsilosis (17.4%), Candida glabrata (16.7%) and Candida tropicalis (10.2%). The prevalence of non-albicans Candida spp. increased over time. Patients had a mean age of 51 years and a mean length of hospital stay prior to BSI of 22 days. The main underlying conditions were gastrointestinal (20.1%) and pulmonary (13.0%) diseases. Intravenous catheters (19.1%) and the urinary tract (8.0%) were the most frequently determined likely sources, whilst in the majority of patients (61.1%) no source could be identified. Overall mortality was 38.1%. Of the isolates studied, 0.8% of C. albicans, 100.0% of C. glabrata, 2.9% of C. parapsilosis and 4.9% of C. tropicalis were non-susceptible to fluconazole, and 0.6% of C. albicans, 5.0% of Candida krusei, 7.6% of C. parapsilosis and 9.8% of C. tropicalis were non-susceptible to voriconazole. All echinocandins showed good activity against most Candida spp., including the majority of C. parapsilosis isolates, but only 38.1% of C. glabrata tested susceptible to caspofungin. Copyright © 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
Yoshida, Haruno; Takahashi, Tetsufumi; Nakamura, Masahiko; Øverby, Anders; Takahashi, Takashi; Ubukata, Kimiko; Matsui, Hidenori
The Streptococcus dysgalactiae subspecies equisimilis (SDSE) possesses clinical similarities to group A streptococcus (GAS) and has recently been recognized as a causative pathogen of life-threatening streptococcal infections. Human membrane cofactor protein (CD46), a complement regulatory protein ubiquitously expressed on every cell type except for erythrocytes, has been implicated as a receptor for human-specific pathogens including GAS. In the present report, SDSE strain GGS_124 was isolated from a patient suffering from streptococcal toxic shock syndrome. When CD46-expressing transgenic (Tg) and non-Tg mice were infected subcutaneously into a hind footpad with 1 × 10(7) colony-forming units of GGS_124, both CD46 Tg and non-Tg mice showed similar levels of colonization in the popliteal lymph nodes at day 3 after infection. However, the following differences were found between CD46 Tg and non-Tg mice after infection. First, there was a statistically significant difference in mortality rates between CD46 Tg (33%) and non-Tg (0%) mice within 35 days after infection. Second, all surviving CD46 Tg mice developed ankle arthritis at day 35 after infection, whereas non-Tg mice did not develop ankle arthritis on the infected hind paws. Finally, CD46 Tg mice developed a pus-filled abscess accompanied by renal failure at day 6 or later after infection. These observations suggest that CD46, the host cell-surface pathogen receptor, functioned to attract GGS_124 into deep tissues, so that the subcutaneous infection with GGS_124 induced invasive streptococcal diseases in CD46 Tg mice. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Meyer, Megan; Jaspers, Ilona
The respiratory epithelium functions as a central orchestrator to initiate and organize responses to inhaled stimuli. Proteases and antiproteases are secreted from the respiratory epithelium and are involved in respiratory homeostasis. Modifications to the protease/antiprotease balance can lead to the development of lung diseases such as emphysema or chronic obstructive pulmonary disease. Furthermore, altered protease/antiprotease balance, in favor for increased protease activity, is associated with increased susceptibility to respiratory viral infections such as influenza virus. However, nutritional antioxidants induce antiprotease expression/secretion and decrease protease expression/activity, to protect against viral infection. As such, this review will elucidate the impact of this balance in the context of respiratory viral infection and lung disease, to further highlight the role epithelial cell-derived proteases and antiproteases contribute to respiratory immune function. Furthermore, this review will offer the use of nutritional antioxidants as possible therapeutics to boost respiratory mucosal responses and/or protect against infection. Copyright © 2015 the American Physiological Society.
Full Text Available A trial was carried out to investigate the susceptibility of seven strains of mice to Strongyloides venezuelensis primary and secondary experimental infections, in order to provide the basis for genetic studies about resistance. Twelve six-week-old male inbred mice of the A/J, BALB/c, CBA/J, C3H/Hepos, C57BL/6, DBA/2 and NIH strains were infected s.c. with 2000 infective larvae. The mean worm counts (± SD in the small intestine six days after infection were, in increasing order: 28 (± 19 in NIH; 647 (± 228 in BALB/c; 709 (± 425 in DBA/2; 731 (± 151 in C3H/Hepos, 801 (± 174 in CBA/J; 1024 (± 267 in C57BL/6 and 1313 (± 483 in A/J. C57BL/6 mice showed the highest fecal egg counts and NIH, the lowest. No eggs in fecal exams or nematodes in small intestines were recovered from animals reinfected 14 days after primary infection. NIH strain was highly resistant to primary infection by S. venezuelensis. The most susceptible of the other six strains appeared to be the C57BL/6 strain which presented a high nematode counting in intestine and the highest egg output.Foi investigada a susceptibilidade de sete linhagens isogênicas de camundongos à infecção experimental, primária e secundária, por Strongyloides venezuelensis a fim de servir de base para estudos genéticos sobre a resistência. Foram utilizados 12 camundongos machos, com seis semanas de idade, das seguintes linhagens isogênicas: A/J, BALB/c, CBA/J, C3H/Hepos, C57BL/6, DBA/2 e NIH. Os animais foram inoculados, via sub-cutânea, com 2000 larvas infectantes. As contagens médias (± desvio padrão de parasitas no intestino delgado dos camundongos seis dias após a infecção, em ordem crescente, foram: 28 (± 19 na linhagem NIH; 647 (± 228 na BALB/c; 709 (± 425 na DBA/2; 731 (± 151 na C3H/Hepos, 801 (± 174 na CBA/J; 1024 (± 267 na C57BL/6 e 1313 (± 483 na A/J. Os camundongos C57BL/6 apresentaram as mais elevadas contagens de ovos de S. venezuelensis por grama de fezes (OPG e os
Uttenthal, Åse; Parida, Satya; Rasmussen, Thomas Bruun