Fincher, Corey L; Thornhill, Randy; Murray, Damian R; Schaller, Mark
Pathogenic diseases impose selection pressures on the social behaviour of host populations. In humans (Homo sapiens), many psychological phenomena appear to serve an antipathogen defence function. One broad implication is the existence of cross-cultural differences in human cognition and behaviour contingent upon the relative presence of pathogens in the local ecology. We focus specifically on one fundamental cultural variable: differences in individualistic versus collectivist values. We suggest that specific behavioural manifestations of collectivism (e.g. ethnocentrism, conformity) can inhibit the transmission of pathogens; and so we hypothesize that collectivism (compared with individualism) will more often characterize cultures in regions that have historically had higher prevalence of pathogens. Drawing on epidemiological data and the findings of worldwide cross-national surveys of individualism/collectivism, our results support this hypothesis: the regional prevalence of pathogens has a strong positive correlation with cultural indicators of collectivism and a strong negative correlation with individualism. The correlations remain significant even when controlling for potential confounding variables. These results help to explain the origin of a paradigmatic cross-cultural difference, and reveal previously undocumented consequences of pathogenic diseases on the variable nature of human societies.
Szekeres, Sándor; Docters van Leeuwen, Arieke; Rigó, Krisztina; Jablonszky, Mónika; Majoros, Gábor; Sprong, Hein; Földvári, Gábor
Tick-borne rickettsioses belong to the important emerging infectious diseases worldwide. We investigated the potential human exposure to rickettsiae by determining their presence in questing ticks collected in an urban park of Budapest and a popular hunting and recreational forest area in southern Hungary. Differences were found in the infectious risk between the two habitats. Rickettsia monacensis and Rickettsia helvetica were identified with sequencing in questing Ixodes ricinus, the only ticks species collected in the city park. Female I. ricinus had a particularly high prevalence of R. helvetica (45%). Tick community was more diverse in the rural habitat with Dermacentor reticulatus ticks having especially high percentage (58%) of Rickettsia raoultii infection. We conclude that despite the distinct eco-epidemiological traits, the risk (hazard and exposure) of acquiring human pathogenic rickettsial infections in both the urban and the rural study sites exists.
Fincher, Corey L; Thornhill, Randy; Murray, Damian R; Schaller, Mark
Pathogenic diseases impose selection pressures on the social behaviour of host populations. In humans (Homo sapiens), many psychological phenomena appear to serve an antipathogen defence function. One broad implication is the existence of cross-cultural differences in human cognition and behaviour contingent upon the relative presence of pathogens in the local ecology. We focus specifically on one fundamental cultural variable: differences in individualistic versus collectivist values. We sug...
Amelia E. Van Pelt
Full Text Available Foodborne illness burdens individuals around the world and may be caused by consuming fresh produce contaminated with bacterial, parasite, and viral pathogens. Pathogen contamination on produce may originate at the farm and packing facility. This research aimed to determine the prevalence of human pathogens (bacteria, parasites, and viruses on fresh produce (fruits, herbs, and vegetables on farms and in packing facilities worldwide through a systematic review of 38 peer-reviewed articles. The median and range of the prevalence was calculated, and Kruskal–Wallis tests and logistic regression were performed to compare prevalence among pooled samples of produce groups, pathogen types, and sampling locations. Results indicated a low median percentage of fresh produce contaminated with pathogens (0%. Both viruses (p-value = 0.017 and parasites (p-value = 0.033, on fresh produce, exhibited higher prevalence than bacteria. No significant differences between fresh produce types or between farm and packing facility were observed. These results may help to better quantify produce contamination in the production environment and inform strategies to prevent future foodborne illness.
Nithya, Angamuthu; Babu, Subramanian
The study aimed at enumerating, identifying and categorizing the endophytic cultivable bacterial community in selected salad vegetables (carrot, cucumber, tomato and onion). Vegetable samples were collected from markets of two vegetable hot spot growing areas, during two different crop harvest seasons. Crude and diluted vegetable extracts were plated and the population of endophytic bacteria was assessed based on morphologically distinguishable colonies. The bacterial isolates were identified by growth in selective media, biochemical tests and 16S rRNA gene sequencing. The endophytic population was found to be comparably higher in cucumber and tomato in both of the sampling locations, whereas lower in carrot and onion. Bacterial isolates belonged to 5 classes covering 46 distinct species belonging to 19 genera. Human opportunistic pathogens were predominant in carrot and onion, whereas plant beneficial bacteria dominated in cucumber and tomato. Out of the 104 isolates, 16.25% are human pathogens and 26.5% are human opportunistic pathogens. Existence of a high population of plant beneficial bacteria was found to have suppressed the population of plant and human pathogens. There is a greater potential to study the native endophytic plant beneficial bacteria for developing them as biocontrol agents against human pathogens that are harboured by plants.
Vanantwerpen, Gerty; Van Damme, Inge; De Zutter, Lieven; Houf, Kurt
Yersiniosis is a common bacterial zoonosis in Europe and healthy pigs are known to be the primary reservoir of human pathogenic Yersinia enterocolitica and Y. pseudotuberculosis. However, little information is available about the prevalence of these pathogens within pig batches at time of slaughter. The tonsils of 7047 fattening pigs, belonging to 100 farms, were aseptically collected immediately after evisceration in two Belgian slaughterhouses. The batch size varied between 70 and 930 pigs. On average, 70 pigs were sampled per batch. The tonsils were examined by direct plating on cefsulodin-irgasan-novobiocin (CIN) agar plates and the number of suspect Yersinia colonies was counted. Pathogenic Y. enterocolitica serotype O:3 were found in tonsils of 2009 pigs (28.5%), originating from 85 farms. The within-batch prevalence in positive farms ranged from 5.1 to 64.4%. The number of Y. enterocolitica in positive pigs varied between 2.01 and 5.98 log10 CFU g(-1) tonsil, with an average of 4.00 log10 CFU g(-1) tonsil. Y. pseudotuberculosis was found in seven farms, for which the within-batch prevalence varied from 2 to 10%. In five of these farms, both Y. enterocolitica and Y. pseudotuberculosis were simultaneously present. Human pathogenic Yersinia spp. are widespread in slaughter pig batches in Belgium as 87% of the tested batches were infected with these pathogens at the time of slaughter. The large variation of the prevalence between batches may lead to different levels of contamination of carcasses and risks for public health. Copyright © 2014 Elsevier B.V. All rights reserved.
Umesha, Kanasinakatte R; Bhavani, Naniah C; Venugopal, Moleyur N; Karunasagar, Indrani; Krohne, Georg; Karunasagar, Iddya
The prevalence of human enteric viruses in bivalve molluscan shellfish and shrimp collected off the south west coast of India was studied to assess the extent of fecal pollution of coastal environment. Out of 194 samples analyzed, 37% of oyster, 46% of clam and 15% of shrimp samples were positive for enteroviruses (EV). Adenoviruses (ADV) were detected in 17% of oyster and 27% of clam samples. However, other enteric viruses such as noroviruses (NoV) and hepatitis A virus (HAV) were not detected in any of the samples. High prevalence of EV and ADV was noticed between May to December. Thirty four percent of oyster and 49% of clam samples showed fecal coliform values higher than the limit. MS-2 phage was detected in 57% of oyster and 73% of clam samples. The presence of MS-2 phage and human enteric viruses showed association while fecal coliforms and enteric viruses showed no association. However, 17 samples, which were positive for enteric viruses (EV and ADV), were negative for MS-2 phage.
Rahikainen Ibañez, T; Laukkanen-Ninios, R; Hakkinen, M; Johansson, T; Vilar, M; Korkeala, H
The prevalence of human pathogenic Yersinia enterocolitica was determined in tonsil and intestinal content samples from 388 healthy fattening pigs at the four biggest Finnish slaughterhouses. These slaughterhouses process 73% of pigs in Finland. Tonsil samples were tested by PCR targeted for yadA, and intestinal samples were cultured. All pathogenic Y. enterocolitica isolates represented bioserotype 4/O:3. The prevalence of Y. enterocolitica in tonsil samples was 60% (95% confidence limit, 55.4 to 65.1%), and its prevalence in intestinal samples was 26% (95% confidence limit, 22.1 to 31.2%). The prevalence of Y. enterocolitica in tonsil and intestinal samples varied between the four slaughterhouses. The tonsil prevalence of Y. enterocolitica was higher in slaughterhouse B, and the prevalence in intestinal content was higher in slaughterhouse C. There were more positive results in both tonsil and intestinal samples in pigs coming from fattening farms than in pigs coming from farrowing-and-fattening farms. A seasonal variation was observed in the prevalence of Y. enterocolitica in intestinal samples, with the highest prevalence during July and August, but no seasonal variation was detected in tonsil samples.
Tybur, J.M.; Lieberman, D.
Over the past few decades, researchers have become increasingly interested in the adaptations guiding the avoidance of disease-causing organisms. Here we discuss the latest developments in this area, including a recently developed information-processing model of the adaptations underlying pathogen
Heitman, Joseph; Carter, Dee A.; Dyer, Paul S.; Soll, David R.
We review here recent advances in our understanding of sexual reproduction in fungal pathogens that commonly infect humans, including Candida albicans, Cryptococcus neoformans/gattii, and Aspergillus fumigatus. Where appropriate or relevant, we introduce findings on other species associated with human infections. In particular, we focus on rapid advances involving genetic, genomic, and population genetic approaches that have reshaped our view of how fungal pathogens evolve. Rather than being asexual, mitotic, and largely clonal, as was thought to be prevalent as recently as a decade ago, we now appreciate that the vast majority of pathogenic fungi have retained extant sexual, or parasexual, cycles. In some examples, sexual and parasexual unions of pathogenic fungi involve closely related individuals, generating diversity in the population but with more restricted recombination than expected from fertile, sexual, outcrossing and recombining populations. In other cases, species and isolates participate in global outcrossing populations with the capacity for considerable levels of gene flow. These findings illustrate general principles of eukaryotic pathogen emergence with relevance for other fungi, parasitic eukaryotic pathogens, and both unicellular and multicellular eukaryotic organisms. PMID:25085958
Full Text Available The aim of this study was to study the prevalence of Salmonella spp., Listeria spp., Staphylococcus spp. and E. coli in the raw cow milk. In this study 133 milk-tank samples from several milk collecting points were analysed. After the tests the following prevalence was detected: for Listeria spp. 13 positive samples (9.77%, with 9 Listeria monocytogenes samples confirmed (6.76%. Salmonella spp. was not detected in any of the the samples. The biggest presence was detected for Staphylococcus spp. with 113 positive samples (85.0%. Further testes has shown prevalence of coagulase-positive staphylococci of 73% (97 positive samples. Escherichia coli was confirmed in 57 samples (46.0%. The results from this study clearly indicate that pathogen microorganisms which are important for the human health can be found in the raw cow milk and their presence can be potential hazard for contamination of the milk-processing establishments.
.... Molecular Detection of Human Bacterial Pathogens addresses this issue, with international scientists in respective bacterial pathogen research and diagnosis providing expert summaries on current...
Gallegos, Belém; Martínez, Ruth; Pérez, Laura; Del Socorro Pina, María; Perez, Eduardo; Hernández, Pedro
Lectins are carbohydrate-binding proteins widely distributed in nature. They constitute a highly diverse group of proteins consisting of many different protein families that are, in general, structurally unrelated. In the last few years, mushroom and other fungal lectins have attracted wide attention due to their antitumour, antiproliferative and immunomodulatory activities. The present mini-review provides concise information about recent developments in understanding lectins from human pathogenic fungi. A bibliographic search was performed in the Science Direct and PubMed databases, using the following keywords "lectin", "fungi", "human" and "pathogenic". Lectins present in fungi have been classified; however, the role played by lectins derived from human pathogenic fungi in infectious processes remains uncertain; thus, this is a scientific field requiring more research. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.
Margaryan, Ashot; Hansen, Henrik B.; Rasmussen, Simon
Recent ancient DNA (aDNA) studies of human pathogens have provided invaluable insights into their evolutionary history and prevalence in space and time. Most of these studies were based on DNA extracted from teeth or postcranial bones. In contrast, no pathogen DNA has been reported from the petro...
Murray, Damian R; Schaller, Mark; Suedfeld, Peter
According to a "parasite stress" hypothesis, authoritarian governments are more likely to emerge in regions characterized by a high prevalence of disease-causing pathogens. Recent cross-national evidence is consistent with this hypothesis, but there are inferential limitations associated with that evidence. We report two studies that address some of these limitations, and provide further tests of the hypothesis. Study 1 revealed that parasite prevalence strongly predicted cross-national differences on measures assessing individuals' authoritarian personalities, and this effect statistically mediated the relationship between parasite prevalence and authoritarian governance. The mediation result is inconsistent with an alternative explanation for previous findings. To address further limitations associated with cross-national comparisons, Study 2 tested the parasite stress hypothesis on a sample of traditional small-scale societies (the Standard Cross-Cultural Sample). Results revealed that parasite prevalence predicted measures of authoritarian governance, and did so even when statistically controlling for other threats to human welfare. (One additional threat-famine-also uniquely predicted authoritarianism.) Together, these results further substantiate the parasite stress hypothesis of authoritarianism, and suggest that societal differences in authoritarian governance result, in part, from cultural differences in individuals' authoritarian personalities.
Full Text Available Certain human bacterial pathogens such as the enterohemorrhagic Escherichia coli and Salmonella enterica are not proven to be plant pathogens yet. Nonetheless, under certain conditions they can survive on, penetrate into, and colonize internal plant tissues causing serious food borne disease outbreaks. In this review, we highlight current understanding on the molecular mechanisms of plant responses against human bacterial pathogens and discuss salient common and contrasting themes of plant interactions with phytopathogens or human pathogens.
Griffin, Dale W.; Donaldson, Kim A.; Paul, J.H.; Rose, Joan B.
This review addresses both historical and recent investigations into viral contamination of marine waters. With the relatively recent emergence of molecular biology-based assays, a number of investigations have shown that pathogenic viruses are prevalent in marine waters being impacted by sewage. Research has shown that this group of fecal-oral viral pathogens (enteroviruses, hepatitis A viruses, Norwalk viruses, reoviruses, adenoviruses, rotaviruses, etc.) can cause a broad range of asymptomatic to severe gastrointestinal, respiratory, and eye, nose, ear, and skin infections in people exposed through recreational use of the water. The viruses and the nucleic acid signature survive for an extended period in the marine environment. One of the primary concerns of public health officials is the relationship between the presence of pathogens and the recreational risk to human health in polluted marine environments. While a number of studies have attempted to address this issue, the relationship is still poorly understood. A contributing factor to our lack of progress in the field has been the lack of sensitive methods to detect the broad range of both bacterial and viral pathogens. The application of new and advanced molecular methods will continue to contribute to our current state of knowledge in this emerging and
Overview: A study was conducted to determine if differences in pathogen prevalence occurred between a sister flock of conventional cage and free range laying hens. Both environmental and egg microbiology was monitored throughout 20 – 79 weeks of age. Salmonella, Campylobacter, and Listeria preval...
The present study was conducted to find out the prevalence and spectrum of Gram negative pathogens causing bacterial meningitis and their antimicrobial susceptibility pattern in a tertiary care hospital. The cerebrospinal fluid (CSF) (3-5 ml) was collected from 638 admitted children clinically suspected of septic meningitis.
This study was carried out to determine the prevalence of mastitis pathogens at the Magadu Dairy Farm, Sokoine University of Agriculture. A total of 19 milk samples were collected and cultured on blood agar and MacConkey agar followed by identification of bacteria colonies and cells using standard laboratory techniques.
Laukkanen-Ninios, Riikka; Fredriksson-Ahomaa, Maria; Maijala, Riitta; Korkeala, Hannu
Samples from pork cuts for minced meat and cheeks from processing plants and a slaughterhouse, and modified atmosphere (MA) packaged pork from retail were studied to estimate the prevalence of pathogenic, i.e. virulence plasmid bearing, Yersinia enterocolitica and Yersinia pseudotuberculosis in pork, as well as to quantify pathogenic Y. enterocolitica in pork cuts. Pathogenic (virF-positive) Y. enterocolitica was isolated from 17 pig cheeks (23%) but not from any of the MA-packaged 54 retail pork samples and only from one of the 155 pork cut (0.6%). Most (16/17) of the cheek samples were contaminated with pathogenic Y. enterocolitica 4/O:3 and one with bioserotype 2/O:9. No Y. pseudotuberculosis was isolated. The prevalence of pathogenic Y. enterocolitica was clearly higher (39%) in 155 pork cuts when studied with nested PCR targeting yadA on the virulence plasmid pYV although the contamination level was low varying between 0.1 and 1.6 MPN/g. Raw pork cuts and especially pig cheeks may serve as possible sources for yersiniosis caused by pathogenic Y. enterocolitica. Copyright © 2014 Elsevier Ltd. All rights reserved.
Rylev, Mette; Kilian, Mogens
putative periodontal pathogens and particular subsets of these species vary between ethnic groups. Few of these differences can, with the limited information available, be directly related to differences in periodontal disease prevalence. Asian populations are regularly colonized with Actinobacillus...... actinomycetemcomitans serotype c with questionable pathogenic potential. Conversely, the JP2 clone of A. actinomycetemcomitans has enhanced virulence and causes significantly higher prevalence of aggressive periodontitis in adolescents whose descent can be traced back to the Mediterranean and Western parts of Africa....... Some genetically distinct types of Porphyromonas gingivalis are more associated with disease than others, but additional work is required to relate this to clinical differences. CONCLUSIONS: Studies that take into account differences linked to the genetics of both patients and potential pathogens...
Introduction: Swine are the only known animal reservoir of Yersinia enterocolitica (YE), a human pathogen. Since YE is a fecal organism of swine, the primary goal of this study was to evaluate the prevalence, serotype, virulence plasmid (pYV)-associated characteristics, clonality, and antibiotic su...
Stege, H.; Jensen, Tim Kåre; Møller, Kristian
Our aim was to determine the prevalence of the intestinal bacteria: Lawsonia intracellularis, Brachyspira hyodysenteriae, Serpulina intermedia, Brachyspira innocens, Brachyspira pilosicoli, pathogenic Escherichia coli (serogroups 0138, 0139, 0141 and 0149) and Salmonella enterica in Danish...... were collected and examined by polymerase chain reaction (PCR) or culture. L. intracellularis was found in 74 herds (93.7%), B. hyodysenteriae in two herds (2.5%), S. intermedia in 10 herds (12.7%), B. innocens in 27 herds (34.2%), B. pilosicoli in 15 herds (19.0%), pathogenic E. call in 19 herds (24...
de Vries, Walter; Berkhout, Ben
RNA silencing or RNAi interference (RNAi) serves as an innate antiviral mechanism in plants, fungi and animals. Human viruses, like plant viruses, encode suppressor proteins or RNAs that block or modulate the RNAi pathway. This review summarizes the mechanisms by which pathogenic human viruses
This study was conducted to determine the incidence of pathogenic microorganisms associated with dental caries and antimicrobial susceptibility test of some common dentifrice sold in Kano metropolis. A total of 50 samples were used in this study. The samples were taken using swab from human oral mucosa. The swabs ...
Martina, Byron E.; Barzon, Luisa; Pijlman, Gorben P.; Fuente, de la José; Rizzoli, Annapaola; Wammes, Linda J.; Takken, Willem; Rij, van Ronald P.; Papa, Anna
Human-to-human (H2H) transmitted arthropod-borne pathogens are a growing burden worldwide, with malaria and dengue being the most common mosquito-borne H2H transmitted diseases. The ability of vectors to get infected by humans during a blood meal to further propel an epidemic depends on complex
Martina, B.E.; Barzon, L.; Pijlman, G.P.; Fuente, J. de la; Rizzoli, A.; Wammes, L.J.; Takken, W.; Rij, R.P. van; Papa, A.
Human-to-human (H2H) transmitted arthropod-borne pathogens are a growing burden worldwide, with malaria and dengue being the most common mosquito-borne H2H transmitted diseases. The ability of vectors to get infected by humans during a blood meal to further propel an epidemic depends on complex
Cavigli, Ian; Daughenbaugh, Katie F; Martin, Madison; Lerch, Michael; Banner, Katie; Garcia, Emma; Brutscher, Laura M; Flenniken, Michelle L
Honey bees are important pollinators of agricultural crops. Since 2006, US beekeepers have experienced high annual honey bee colony losses, which may be attributed to multiple abiotic and biotic factors, including pathogens. However, the relative importance of these factors has not been fully elucidated. To identify the most prevalent pathogens and investigate the relationship between colony strength and health, we assessed pathogen occurrence, prevalence, and abundance in Western US honey bee colonies involved in almond pollination. The most prevalent pathogens were Black queen cell virus (BQCV), Lake Sinai virus 2 (LSV2), Sacbrood virus (SBV), Nosema ceranae , and trypanosomatids. Our results indicated that pathogen prevalence and abundance were associated with both sampling date and beekeeping operation, that prevalence was highest in honey bee samples obtained immediately after almond pollination, and that weak colonies had a greater mean pathogen prevalence than strong colonies.
Hyypia, T.; Huovinen, P.; Holmberg, M.; Pettersson, U.
The development of effective vaccines and antimicrobial drugs against infectious diseases has been among the most successful achievements in modern medicine. The control of these diseases requires efficient diagnostic methods for the evaluation of the prevalence of diseases and for initiation of specific treatment. Virtually all known microbes can be specifically identified today but in many cases further development is needed for more accurate, rapid, easy-to-use, and inexpensive diagnostic assays. Cell culture facilities are needed for the isolation of viruses in clinical specimens. Any gene of any known microorganism can be cloned in a vector and produced in large amounts economically and then used in diagnostic assays for the identification of the pathogen. The application of the nucleic acid hybridization methods in detection of human pathogens has received considerable attention during the past few years. This paper presents examples of this application of gene technology
Newburg, D S
Breast-fed infants have lower incidence of diarrhea, respiratory disease, and otitis media. The protection by human milk has long been attributed to the presence of secretory IgA. However, human milk contains large numbers and amounts of complex carbohydrates, including glycoproteins, glycolipids, glycosaminoglycans, mucins, and especially oligosaccharides. The oligosaccharides comprise the third most abundant solid constituent of human milk, and contain a myriad of structures. Complex carbohydrate moieties of glycoconjugates and oligosaccharides are synthesized by the many glycosyltransferases in the mammary gland; those with homology to cell surface glycoconjugate pathogen receptors may inhibit pathogen binding, thereby protecting the nursing infant. Several examples are reviewed: A fucosyloligosaccharide inhibits the diarrheagenic effect of stable toxin of Escherichia coli. A different fucosyloligosaccharide inhibits infection by Campylobacter jejuni. Binding of Streptococcus pneumoniae and of enteropathogenic E. coli to their respective receptors is inhibited by human milk oligosaccharides. The 46-kD glycoprotein, lactadherin, inhibits rotavirus binding and infectivity. Low levels of lactadherin in human milk are associated with a higher incidence of symptomatic rotavirus in breast-fed infants. A mannosylated glycopeptide inhibits binding by enterohemorrhagic E. coli. A glycosaminoglycan inhibits binding of gp120 to CD4, the first step in HIV infection. Human milk mucin inhibits binding by S-fimbriated E. coli. The ganglioside, GM1, reduces diarrhea production by cholera toxin and labile toxin of E. coli. The neutral glycosphingolipid, Gb3, binds to Shigatoxin. Thus, many complex carbohydrates of human milk may be novel antipathogenic agents, and the milk glycoconjugates and oligosaccharides may be a major source of protection for breastfeeding infants.
Full Text Available Ettawa Grade (PE are potentially developed goats to produce milk and meat. Milk is food of animal that is rich in nutrients, but it is a perishable food easily contaminated by microorganisms. Contaminated pathogenic bacteria in milk can decrease the quality and has an organoleptic effect on milk, as well as endangers human health. Milk contaminated with bacteria antimicrobial resistance (AMR in which is resistant to antibiotics, may adversely affect the response to treatment with antibiotics in humans when suffering from infectious diseases and using antibiotics in therapy. In this study Ettawa Grade's samples of fresh milk and other dairy products were taken from some of the goat farms in Yogyakarta Sleman district. The samples were tested for the presence of pathogenic bacteria and for its resistance to several kinds of antibiotics. In this study 35 Ettawa Grade's samples of fresh milk and other dairy products (fresh milk, milk powder, ice cream, and yoghurt were taken from some of the goat farms in Sleman district-Yogyakarta. The samples were tested for the presence of pathogenic bacteria and for its resistance to several kinds of antibiotics. The result of the prevalence of pathogenic bacteria in goat fresh milk and other dairy products was 15% Escherichia coli and had multi resistance to multiple antibiotics, namely ampicillin, colistin sulphate, cefixime, kanamycin, oxytetracycline, tetracycline and sulfonamide.
Full Text Available Description of the subject. The growth of new antibiotic-resistant strains of pathogens represents a huge problem in poultry rearing. There is evidence that dietary yeast could be effective in the protection against a variety of pathogens that can affect poultry health and cause foodborne diseases in humans. Since still few or contradictory information are available for this topic. Objectives. The objective of this study was to investigate the effects of live yeast supplementation in broiler chickens on Salmonella enteritidis and Campylobacter jejuni content in feces, cecum, and skin. Method. Supplemented yeast consisted of Saccharomyces cerevisiae (Levucell® SB20, type boulardii I-1079, Lallemand, France and was administered at a rate of 1 x 106 CFU·g-1 of feed. On day ten of life, birds were orally challenged with S. enteritidis (1 x 105 CFU/bird and C. jejuni (3 x 105 CFU/bird. Growth performance, and coliforms, yeasts and lactobacilli enumeration were evaluated on day 0, 10, 20 and 38. Ten and eighteen days post infection (PI, 10 animals per replicate were slaughtered and pooled ceca content were analyzed for yeast enumeration and Salmonella and Campylobacter frequency and enumeration. The presence and the enumeration of Salmonella and Campylobacter in neck and breast skin were performed on one subject per replicate. Results. Dietary S. cerevisiae increased yeast and lactobacilli (p = 0.01 count, while Salmonella enumeration and frequency significantly decreased in neck (p = 0.03 and tended to decrease in cecum (p = 0.06, feces (p = 0.06, and breast (p = 0.08. On 10d PI Campylobacter presence was decreased in cecum (p = 0.01, feces (p < 0.01, breast skin (p = 0.04 and neck skin (p < 0.01, while the enumeration was found to be lower in feces (p < 0.01 and neck skin (p = 0.05. At the end of the trial the frequency of this pathogen was decreased in feces (p < 0.01, and breast skin (p = 0.02, while the enumeration was diminished in cecum (p
Tickell, Kirkby D; Pavlinac, Patricia B; John-Stewart, Grace C; Denno, Donna M; Richardson, Barbra A; Naulikha, Jaqueline M; Kirera, Ronald K; Swierczewski, Brett E; Singa, Benson O; Walson, Judd L
Children with acute and chronic malnutrition are at increased risk of morbidity and mortality following a diarrheal episode. To compare diarrheal disease severity and pathogen prevalence among children with and without acute and chronic malnutrition, we conducted a cross-sectional study of human immunodeficiency virus-uninfected Kenyan children aged 6-59 months, who presented with acute diarrhea. Children underwent clinical and anthropometric assessments and provided stool for bacterial and protozoal pathogen detection. Clinical and microbiological features were compared using log binomial regression among children with and without wasting (mid-upper arm circumference ≤ 125 mm) or stunting (height-for-age z score ≤ -2). Among 1,363 children, 7.0% were wasted and 16.9% were stunted. After adjustment for potential confounders, children with wasting were more likely than nonwasted children to present with at least one Integrated Management of Childhood Illness danger sign (adjusted prevalence ratio [aPR]: 1.3, 95% confidence interval [CI]: 1.0 to 1.5, P = 0.05), severe dehydration (aPR: 2.4, 95% CI: 1.5 to 3.8, P malnutrition which may be explained by a delay in care-seeking or diminished immune response to infection. Combating social determinants and host risk factors associated with severe disease, rather than specific pathogens, may reduce the disparities in poor diarrhea-associated outcomes experienced by malnourished children.
Abstract Breastfeeding protects the neonate against pathogen infection. Major mechanisms of protection include human milk glycoconjugates functioning as soluble receptor mimetics that inhibit pathogen binding to the mucosal cell surface, prebiotic stimulation of gut colonization by favorable microbiota, immunomodulation, and as a substrate for bacterial fermentation products in the gut. Human milk proteins are predominantly glycosylated, and some biological functions of these human milk glycoproteins (HMGPs) have been reported. HMGPs range in size from 14 kDa to 2,000 kDa and include mucins, secretory immunoglobulin A, bile salt-stimulated lipase, lactoferrin, butyrophilin, lactadherin, leptin, and adiponectin. This review summarizes known biological roles of HMGPs that may contribute to the ability of human milk to protect neonates from disease. PMID:23697737
Olusola L. Ajayi
Full Text Available There is paucity of information on the prevalence of leptospirosis in wildlife in Nigeria. This study investigated the prevalence and renal pathology of leptospirosis in wild animals in Southwest Nigeria. One hundred and five kidney samples were examined from 10 different wildlife species (antelope greater cane rat (GCR, hare, African giant rat (AGR, tree hyrax, civet cat, monitor lizard, python, bushbuck and partridge using a combination of Ellinghausen McCullough Johnson Harris (EMJH medium, microscopic agglutination test (MAT, Warthin– Starry silver stain (WSss and immunohistochemistry. Chi-square test was used with confidence level set at 0.05 to ascertain associations between positive cases and sex and species. Eightytwo (78.1% samples were culturally positive, while 67.7% (63/93, 57.0% (16/28 and 66.7% (8/12 were WSss, MAT and immunohistochemically positive, respectively. Interstitial nephritis (41.0% and tubular nephrosis (81.0% were the most prominent histopathological changes. Pathogenic Leptospira organisms were highest in GCR (32.1% and antelope (14.3%. Serovars hardjo (11.54%, bratislava (3.9%, canicola (3.9%, icterohaemorrhagiae (15.4%, pomona (7.14% gripptotyphosa (19.2% and undetermined isolates were also detected in other animals. The result showed high prevalence of Leptospira infection in the wild and the possibility of domestic animals and humans contracting the disease. This study is the first documentation of evidence of pathogenic Leptospira species in wildlife in Nigeria.
Fernández, Francisco J; Gómez, Sara; Vega, M Cristina
The surveillance and pathogen fighting functions of the complement system have evolved to protect mammals from life-threatening infections. In turn, pathogens have developed complex molecular mechanisms to subvert, divert and evade the effector functions of the complement. The study of complement immunoevasion by pathogens sheds light on their infection drivers, knowledge that is essential to implement therapies. At the same time, complement evasion also acts as a discovery ground that reveals important aspects of how complement works under physiological conditions. In recent years, complex interrelationships between infection insults and the onset of autoimmune and complement dysregulation diseases have led to propose that encounters with pathogens can act as triggering factors for disease. The correct management of these diseases involves the recognition of their triggering factors and the development and administration of complement-associated molecular therapies. Even more recently, unsuspected proteins from pathogens have been shown to possess moonlighting functions as virulence factors, raising the possibility that behind the first line of virulence factors there be many more pathogen proteins playing secondary, helping and supporting roles for the pathogen to successfully establish infections. In an era where antibiotics have a progressively reduced effect on the management and control of infectious diseases worldwide, knowledge on the mechanisms of pathogenic invasion and evasion look more necessary and pressing than ever. Copyright © 2017 Elsevier Ltd. All rights reserved.
Abdel-Moein, Khaled A; Hamza, Dalia A
The current study was conducted to investigate the occurrence of human pathogenic Clostridium botulinum in the feces of dairy animals. Fecal samples were collected from 203 apparently healthy dairy animals (50 cattle, 50 buffaloes, 52 sheep, 51 goats). Samples were cultured to recover C. botulinum while human pathogenic C. botulinum strains were identified after screening of all C. botulinum isolates for the presence of genes that encode toxins type A, B, E, F. The overall prevalence of C. botulinum was 18.7% whereas human pathogenic C. botulinum strains (only type A) were isolated from six animals at the rates of 2, 2, 5.8, and 2% for cattle, buffaloes, sheep, and goats, respectively. High fecal carriage rates of C. botulinum among apparently healthy dairy animals especially type A alarm both veterinary and public health communities for a potential role which may be played by dairy animals in the epidemiology of such pathogen.
Rylev, Mette; Kilian, Mogens
. Some genetically distinct types of Porphyromonas gingivalis are more associated with disease than others, but additional work is required to relate this to clinical differences. CONCLUSIONS: Studies that take into account differences linked to the genetics of both patients and potential pathogens...
With the advent of 21st century technology that has resulted in the development of sophisticated equipments, blood supply is thought to be safer than ever. This study therefore, investigates the incidence and prevalence of transfusion transmitted infections in patients. The study was carried out on 55 hospitalized cohorts who ...
Full Text Available Streptococcus agalactiae, or Group B Streptococcus (GBS, is a major pathogen causing neonatal sepsis and meningitis, bovine mastitis, and fish meningoencephalitis. CC23, including its namesake ST23, is not only the predominant GBS strain derived from human and cattle, but also can infect a variety of homeothermic and poikilothermic species. However, it has never been characterized in fish. This study aimed to determine the pathogenicity of ST23 GBS to fish and explore the mechanisms causing the difference in the pathogenicity of ST23 GBS based on the genome analysis. Infection of tilapia with 10 human-derived ST23 GBS isolates caused tissue damage and the distribution of pathogens within tissues. The mortality rate of infection was ranged from 76 to 100%, and it was shown that the mortality rate caused by only three human isolates had statistically significant difference compared with fish-derived ST7 strain (P < 0.05, whereas the mortality caused by other seven human isolates did not show significant difference compared with fish-derived ST7 strain. The genome comparison and prophage analysis showed that the major genome difference between virulent and non-virulent ST23 GBS was attributed to the different prophage sequences. The prophage in the P1 region contained about 43% GC and encoded 28–39 proteins, which can mediate the acquisition of YafQ/DinJ structure for GBS by phage recombination. YafQ/DinJ belongs to one of the bacterial toxin–antitoxin (TA systems and allows cells to cope with stress. The ST23 GBS strains carrying this prophage were not pathogenic to tilapia, but the strains without the prophage or carrying the pophage that had gene mutation or deletion, especially the deletion of YafQ/DinJ structure, were highly pathogenic to tilapia. In conclusion, human ST23 GBS is highly pathogenic to fish, which may be related to the phage recombination.
Klubal, Radek; Kopecky, Jan; Nesvorna, Marta; Sparagano, Olivier A E; Thomayerova, Jana; Hubert, Jan
Bacteria associated with the tick Ixodes ricinus were assessed in specimens unattached or attached to the skin of cats, dogs and humans, collected in the Czech Republic. The bacteria were detected by PCR in 97 of 142 pooled samples including 204 ticks, i.e. 1-7 ticks per sample, collected at the same time from one host. A fragment of the bacterial 16S rRNA gene was amplified, cloned and sequenced from 32 randomly selected samples. The most frequent sequences were those related to Candidatus Midichloria midichlori (71% of cloned sequences), followed by Diplorickettsia (13%), Spiroplasma (3%), Rickettsia (3%), Pasteurella (3%), Morganella (3%), Pseudomonas (2%), Bacillus (1%), Methylobacterium (1%) and Phyllobacterium (1%). The phylogenetic analysis of Spiroplasma 16S rRNA gene sequences showed two groups related to Spiroplasma eriocheiris and Spiroplasma melliferum, respectively. Using group-specific primers, the following potentially pathogenic bacteria were detected: Borellia (in 20% of the 142 samples), Rickettsia (12%), Spiroplasma (5%), Diplorickettsia (5%) and Anaplasma (2%). In total, 68% of I. ricinus samples (97/142) contained detectable bacteria and 13% contained two or more putative pathogenic groups. The prevalence of tick-borne bacteria was similar to the observations in other European countries.
human herpesvirus 8 (HHV 8): Distribution of infection in Kaposi's sarcoma risk groups and evidence of sexual transmission. Nat Med 1996; 2: 918-924. 14. Kedes OH, Ganem 0, Ameli N, Bacchetti p. Greenblatt R The prevalence of serum antibody to human herpesvirus 8 (Kaposi sarcoma-associated hepesvirus) among ...
Jesse S Lewis
Full Text Available Transmission of pathogens among animals is influenced by demographic, social, and environmental factors. Anthropogenic alteration of landscapes can impact patterns of disease dynamics in wildlife populations, increasing the potential for spillover and spread of emerging infectious diseases in wildlife, human, and domestic animal populations. We evaluated the effects of multiple ecological mechanisms on patterns of pathogen exposure in animal populations. Specifically, we evaluated how ecological factors affected the prevalence of Toxoplasma gondii (Toxoplasma, Bartonella spp. (Bartonella, feline immunodeficiency virus (FIV, and feline calicivirus (FCV in bobcat and puma populations across wildland-urban interface (WUI, low-density exurban development, and wildland habitat on the Western Slope (WS and Front Range (FR of Colorado during 2009-2011. Samples were collected from 37 bobcats and 29 pumas on the WS and FR. As predicted, age appeared to be positively related to the exposure to pathogens that are both environmentally transmitted (Toxoplasma and directly transmitted between animals (FIV. In addition, WS bobcats appeared more likely to be exposed to Toxoplasma with increasing intraspecific space-use overlap. However, counter to our predictions, exposure to directly-transmitted pathogens (FCV and FIV was more likely with decreasing space-use overlap (FCV: WS bobcats and potential intraspecific contacts (FIV: FR pumas. Environmental factors, including urbanization and landscape covariates, were generally unsupported in our models. This study is an approximation of how pathogens can be evaluated in relation to demographic, social, and environmental factors to understand pathogen exposure in wild animal populations.
Corinne P. Oechslin
Full Text Available Abstract Background Throughout Europe, Ixodes ricinus transmits numerous pathogens. Its widespread distribution is not limited to rural but also includes urbanized areas. To date, comprehensive data on pathogen carrier rates of I. ricinus ticks in urban areas of Switzerland is lacking. Results Ixodes ricinus ticks sampled at 18 (sub- urban collection sites throughout Switzerland showed carrier rates of 0% for tick-borne encephalitis virus, 18.0% for Borrelia burgdorferi (sensu lato, 2.5% for Borrelia miyamotoi, 13.5% for Rickettsia spp., 1.4% for Anaplasma phagocytophilum, 6.2% for "Candidatus Neoehrlichia mikurensis", and 0.8% for Babesia venatorum (Babesia sp., EU1. Site-specific prevalence at collection sites with n > 45 ticks (n = 9 significantly differed for B. burgdorferi (s.l., Rickettsia spp., and "Ca. N. mikurensis", but were not related to the habitat type. Three hundred fifty eight out of 1078 I. ricinus ticks (33.2% tested positive for at least one pathogen. Thereof, about 20% (71/358 were carrying two or three different potentially disease-causing agents. Using next generation sequencing, we could detect true pathogens, tick symbionts and organisms of environmental or human origin in ten selected samples. Conclusions Our data document the presence of pathogens in the (sub- urban I. ricinus tick population in Switzerland, with carrier rates as high as those in rural regions. Carriage of multiple pathogens was repeatedly observed, demonstrating the risk of acquiring multiple infections as a consequence of a tick bite.
Brearley, Grant; Rhodes, Jonathan; Bradley, Adrian; Baxter, Greg; Seabrook, Leonie; Lunney, Daniel; Liu, Yan; McAlpine, Clive
Human-induced landscape change associated with habitat loss and fragmentation places wildlife populations at risk. One issue in these landscapes is a change in the prevalence of disease which may result in increased mortality and reduced fecundity. Our understanding of the influence of habitat loss and fragmentation on the prevalence of wildlife diseases is still in its infancy. What is evident is that changes in disease prevalence as a result of human-induced landscape modification are highly variable. The importance of infectious diseases for the conservation of wildlife will increase as the amount and quality of suitable habitat decreases due to human land-use pressures. We review the experimental and observational literature of the influence of human-induced landscape change on wildlife disease prevalence, and discuss disease transmission types and host responses as mechanisms that are likely to determine the extent of change in disease prevalence. It is likely that transmission dynamics will be the key process in determining a pathogen's impact on a host population, while the host response may ultimately determine the extent of disease prevalence. Finally, we conceptualize mechanisms and identify future research directions to increase our understanding of the relationship between human-modified landscapes and wildlife disease prevalence. This review highlights that there are rarely consistent relationships between wildlife diseases and human-modified landscapes. In addition, variation is evident between transmission types and landscape types, with the greatest positive influence on disease prevalence being in urban landscapes and directly transmitted disease systems. While we have a limited understanding of the potential influence of habitat loss and fragmentation on wildlife disease, there are a number of important areas to address in future research, particularly to account for the variability in increased and decreased disease prevalence. Previous studies
Doxey, Andrew C; McConkey, Brendan J
Molecular mimicry of host proteins is a common strategy adopted by bacterial pathogens to interfere with and exploit host processes. Despite the availability of pathogen genomes, few studies have attempted to predict virulence-associated mimicry relationships directly from genomic sequences. Here, we analyzed the proteomes of 62 pathogenic and 66 non-pathogenic bacterial species, and screened for the top pathogen-specific or pathogen-enriched sequence similarities to human proteins. The screen identified approximately 100 potential mimicry relationships including well-characterized examples among the top-scoring hits (e.g., RalF, internalin, yopH, and others), with about 1/3 of predicted relationships supported by existing literature. Examination of homology to virulence factors, statistically enriched functions, and comparison with literature indicated that the detected mimics target key host structures (e.g., extracellular matrix, ECM) and pathways (e.g., cell adhesion, lipid metabolism, and immune signaling). The top-scoring and most widespread mimicry pattern detected among pathogens consisted of elevated sequence similarities to ECM proteins including collagens and leucine-rich repeat proteins. Unexpectedly, analysis of the pathogen counterparts of these proteins revealed that they have evolved independently in different species of bacterial pathogens from separate repeat amplifications. Thus, our analysis provides evidence for two classes of mimics: complex proteins such as enzymes that have been acquired by eukaryote-to-pathogen horizontal transfer, and simpler repeat proteins that have independently evolved to mimic the host ECM. Ultimately, computational detection of pathogen-specific and pathogen-enriched similarities to host proteins provides insights into potentially novel mimicry-mediated virulence mechanisms of pathogenic bacteria.
Borlot, Felippe; Regan, Brigid M; Bassett, Anne S; Stavropoulos, D James; Andrade, Danielle M
Copy number variation (CNV) is an important cause of neuropsychiatric disorders. Little is known about the role of CNV in adults with epilepsy and intellectual disability. To evaluate the prevalence of pathogenic CNVs and identify possible candidate CNVs and genes in patients with epilepsy and intellectual disability. In this cross-sectional study, genome-wide microarray was used to evaluate a cohort of 143 adults with unexplained childhood-onset epilepsy and intellectual disability who were recruited from the Toronto Western Hospital epilepsy outpatient clinic from January 1, 2012, through December 31, 2014. The inclusion criteria were (1) pediatric seizure onset with ongoing seizure activity in adulthood, (2) intellectual disability of any degree, and (3) no structural brain abnormalities or metabolic conditions that could explain the seizures. DNA screening was performed using genome-wide microarray platforms. Pathogenicity of CNVs was assessed based on the American College of Medical Genetics guidelines. The Residual Variation Intolerance Score was used to evaluate genes within the identified CNVs that could play a role in each patient's phenotype. Of the 2335 patients, 143 probands were investigated (mean [SD] age, 24.6 [10.8] years; 69 male and 74 female). Twenty-three probands (16.1%) and 4 affected relatives (2.8%) (mean [SD] age, 24.1 [6.1] years; 11 male and 16 female) presented with pathogenic or likely pathogenic CNVs (0.08-18.9 Mb). Five of the 23 probands with positive results (21.7%) had more than 1 CNV reported. Parental testing revealed de novo CNVs in 11 (47.8%), with CNVs inherited from a parent in 4 probands (17.4%). Sixteen of 23 probands (69.6%) presented with previously cataloged human genetic disorders and/or defined CNV hot spots in epilepsy. Eight nonrecurrent rare CNVs that overlapped 1 or more genes associated with intellectual disability, autism, and/or epilepsy were identified: 2p16.1-p15 duplication, 6p25.3-p25.1 duplication, 8p23.3p
Warinner, Christina; Matias Rodrigues, João F.; Vyas, Rounak; Trachsel, Christian; Shved, Natallia; Grossmann, Jonas; Radini, Anita; Hancock, Y.; Tito, Raul Y.; Fiddyment, Sarah; Speller, Camilla; Hendy, Jessica; Charlton, Sophy; Luder, Hans Ulrich; Salazar-García, Domingo C.; Eppler, Elisabeth; Seiler, Roger; Hansen, Lars; Samaniego Castruita, José Alfredo; Barkow-Oesterreicher, Simon; Teoh, Kai Yik; Kelstrup, Christian; Olsen, Jesper V.; Nanni, Paolo; Kawai, Toshihisa; Willerslev, Eske; von Mering, Christian; Lewis, Cecil M.; Collins, Matthew J.; Gilbert, M. Thomas P.; Rühli, Frank; Cappellini, Enrico
Calcified dental plaque (dental calculus) preserves for millennia and entraps biomolecules from all domains of life and viruses. We report the first high-resolution taxonomic and protein functional characterization of the ancient oral microbiome and demonstrate that the oral cavity has long served as a reservoir for bacteria implicated in both local and systemic disease. We characterize: (i) the ancient oral microbiome in a diseased state, (ii) 40 opportunistic pathogens, (iii) the first evidence of ancient human-associated putative antibiotic resistance genes, (iv) a genome reconstruction of the periodontal pathogen Tannerella forsythia, (v) 239 bacterial and 43 human proteins, allowing confirmation of a long-term association between host immune factors, “red-complex” pathogens, and periodontal disease, and (vi) DNA sequences matching dietary sources. Directly datable and nearly ubiquitous, dental calculus permits the simultaneous investigation of pathogen activity, host immunity, and diet, thereby extending the direct investigation of common diseases into the human evolutionary past. PMID:24562188
Knowledge and prevalence of Human African Trypanosomiasis among residents of Kachia grazing reserve, Kachia local government area, Kaduna state, ... Knowledge of HAT was scored 0-5 and categorized good (3-5) and poor (0-2) based on score, predisposition to risk of HAT as exposure to ≥two risk factors and, ...
Full Text Available Crown rot pathogens are associated with higher losses for wheat crop farmers, but information about the distribution and prevalence of these pathogens in Chile is inadequate. Distribution and prevalence of wheat (Triticum aestivum L. crown rot pathogens were examined in a survey of 48 commercial fields from December 2011 to February 2012 in southern Chile. These fields were located between Collipulli (37°56'00" S; 72°26'39" W and Purranque (40°50'30" S; 73°22'03" W. Severity of crown rot disease was determined through visual assessment of the first internode of 20 tillers obtained from each field. Incidence of crown rot pathogens per field was determined by plating the 20 tillers on Petri plates with 20% potato dextrose agar amended with lactic acid (aPDA medium. Resulting fungal colonies from monoxenic culture were identified by morphological or molecular-assisted identification. Severity of crown rot varied between 11.3% and 80% for individual fields. Culture plate analysis showed 72.2% of stems were infected with some fungus. Fusarium avenaceum, F. graminearum, and F. culmorum, pathogens associated with Fusarium crown rot disease were isolated from 13.5% of tillers. Gaeumannomyces graminis, causal agent of take-all disease in cereals, was isolated from 11.1% of culms. Phaeosphaeria sp., an endophyte and possibly a non-pathogenic fungus, was isolated from 13.9% of tillers. Pathogenic fungi such as Rhizoctonia spp. and Microdochium nivale, other saprophyte, and several unidentified non-sporulating fungi were isolated at frequencies lower than 3% of the total. Fusarium crown rot and take-all were the most prevalent and distributed crown rot diseases present in wheat crops in southern Chile.
Full Text Available The objective of this study was to investigate and summarize the levels of incidence of Salmonella spp., Listeria monocytogenes, Staphylococcus aureus and Campylobacter spp. in poultry meat commercialized in Europe. After systematic review, incidence data and study characteristics were extracted from 78 studies conducted in 21 European countries. Pooled prevalence values from 203 extracted observations were estimated from random-effects meta-analysis models adjusted by pathogen, poultry type, sampling stage, cold preservation type, meat cutting type and packaging status. The results suggest that S. aureus is the main pathogen detected in poultry meat (38.5%; 95% CI: 25.4–53.4, followed by Campylobacter spp. (33.3%; 95% CI: 22.3–46.4%, while L. monocytogenes and Salmonella spp. present lower prevalence (19.3%; 95% CI: 14.4–25.3% and 7.10%; 95% CI: 4.60–10.8%, respectively. Despite the differences in prevalence, all pathogens were found in chicken and other poultry meats, at both end-processing step and retail level, in packed and unpacked products and in several meat cutting types. Prevalence data on cold preservation products also revealed that chilling and freezing can reduce the proliferation of pathogens but might not be able to inactivate them. The results of this meta-analysis highlight that further risk management strategies are needed to reduce pathogen incidence in poultry meat throughout the entire food chain across Europe, in particular for S. aureus and Campylobacter spp.
Warinner, Christina; Rodrigues, João F Matias; Vyas, Rounak
Calcified dental plaque (dental calculus) preserves for millennia and entraps biomolecules from all domains of life and viruses. We report the first, to our knowledge, high-resolution taxonomic and protein functional characterization of the ancient oral microbiome and demonstrate that the oral...... cavity has long served as a reservoir for bacteria implicated in both local and systemic disease. We characterize (i) the ancient oral microbiome in a diseased state, (ii) 40 opportunistic pathogens, (iii) ancient human-associated putative antibiotic resistance genes, (iv) a genome reconstruction...... calculus permits the simultaneous investigation of pathogen activity, host immunity and diet, thereby extending direct investigation of common diseases into the human evolutionary past....
Mendoza, Leonel; Vilela, Raquel; Voelz, Kerstin; Ibrahim, Ashraf S; Voigt, Kerstin; Lee, Soo Chan
In recent years, we have seen an increase in the number of immunocompromised cohorts as a result of infections and/or medical conditions, which has resulted in an increased incidence of fungal infections. Although rare, the incidence of infections caused by fungi belonging to basal fungal lineages is also continuously increasing. Basal fungal lineages diverged at an early point during the evolution of the fungal lineage, in which, in a simplified four-phylum fungal kingdom, Zygomycota and Chytridiomycota belong to the basal fungi, distinguishing them from Ascomycota and Basidiomycota. Currently there are no known human infections caused by fungi in Chytridiomycota; only Zygomycotan fungi are known to infect humans. Hence, infections caused by zygomycetes have been called zygomycosis, and the term "zygomycosis" is often used as a synonym for "mucormycosis." In the four-phylum fungal kingdom system, Zygomycota is classified mainly based on morphology, including the ability to form coenocytic (aseptated) hyphae and zygospores (sexual spores). In the Zygomycota, there are 10 known orders, two of which, the Mucorales and Entomophthorales, contain species that can infect humans, and the infection has historically been known as zygomycosis. However, recent multilocus sequence typing analyses (the fungal tree of life [AFTOL] project) revealed that the Zygomycota forms not a monophyletic clade but instead a polyphyletic clade, whereas Ascomycota and Basidiomycota are monophyletic. Thus, the term "zygomycosis" needed to be further specified, resulting in the terms "mucormycosis" and "entomophthoramycosis." This review covers these two different types of fungal infections. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.
Fresh produce, viewed as an essential part of a healthy life style is usually consumed in the form of raw or minimally processed fruits and vegetables, and is a potentially important source of food-borne human pathogenic bacteria and viruses. These are passed on to the consumer since the bacteria ca...
Waalwijk, C.; Tongeren, van C.A.M.; Zouwen, van der P.S.; Overbeek, van L.S.
The 2011 enterohaemorrhagic Escherichia coli (EHEC) outbreak in Germany casted new light on the potential reservoirs of human pathogenic bacteria (HUPA) other than the ones commonly recognized in animal production chains. Soil, plants and water systems were demonstrated to be environments where HUPA
Full Text Available Phytoviruses are highly prevalent in plants worldwide, including vegetables and fruits. Humans, and more generally animals, are exposed daily to these viruses, among which several are extremely stable. It is currently accepted that a strict separation exists between plant and vertebrate viruses regarding their host range and pathogenicity, and plant viruses are believed to infect only plants. Accordingly, plant viruses are not considered to present potential pathogenicity to humans and other vertebrates. Notwithstanding these beliefs, there are many examples where phytoviruses circulate and propagate in insect vectors. Several issues are raised here that question if plant viruses might further cross the kingdom barrier to cause diseases in humans. Indeed, there is close relatedness between some plant and animal viruses, and almost identical gene repertoires. Moreover, plant viruses can be detected in non-human mammals and humans samples, and there are evidence of immune responses to plant viruses in invertebrates, non-human vertebrates and humans, and of the entry of plant viruses or their genomes into non-human mammal cells and bodies after experimental exposure. Overall, the question raised here is unresolved, and several data prompt the additional extensive study of the interactions between phytoviruses and non-human mammals and humans, and the potential of these viruses to cause diseases in humans.
Boschiroli, Maria L; Falkinham, Joseph; Favre-Bonte, Sabine; Nazaret, Sylvie; Piveteau, Pascal; Sadowsky, Michael J.; Byappanahalli, Muruleedhara; Delaquis, Pascal; Hartmann, Alain
Soils receive inputs of human pathogenic and indicator bacteria through land application of animal manures or sewage sludge, and inputs by wildlife. Soil is an extremely heterogeneous substrate and contains meso- and macrofauna that may be reservoirs for bacteria of human health concern. The ability to detect and quantify bacteria of human health concern is important in risk assessments and in evaluating the efficacy of agricultural soil management practices that are protective of crop quality and protective of adjacent water resources. The present chapter describes the distribution of selected Gram-positive and Gram-negative bacteria in soils. Methods for detecting and quantifying soilborne bacteria including extraction, enrichment using immunomagnetic capture, culturing, molecular detection and deep sequencing of metagenomic DNA to detect pathogens are overviewed. Methods for strain phenotypic and genotypic characterization are presented, as well as how comparison with clinical isolates can inform the potential for human health risk.
Chantziaras, Ilias; Dewulf, Jeroen; Boyen, Filip; Callens, Benedicte; Butaye, Patrick
In this article, detailed studies on antimicrobial resistance to commensal E. coli (in pigs, meat-producing bovines, broiler chickens and veal calves) and pathogenic E. coli (in pigs and bovines) in Belgium are presented for 2011. Broiler chicken and veal calf isolates of commensal E. coli demonstrated higher antimicrobial resistance prevalence than isolates from pigs and bovines. Fifty percent of E. coli isolates from broiler chickens were resistant to at least five antimicrobials, whereas s...
Shabbir, Muhammad Z.; Jamil, Tariq; Ali, Asad A.; Ahmad, Arfan; Naeem, Muhammad; Chaudhary, Muhammad H.; Bilal, Muhammad; Ali, Muhammad A.; Muhammad, Khushi; Yaqub, Tahir; Bano, Asghari; Mirza, Ali I.; Shabbir, Muhammad A. B.; McVey, Walter R.; Patel, Ketan
A multidisciplinary, collaborative project was conducted to determine the prevalence and distribution of soil-borne zoonotic pathogens in Lahore district of Pakistan and ascertain its Public Health Significance. Using a grid-based sampling strategy, soil samples (n = 145) were collected from villages (n = 29, 5 samples/village) and examined for Bacillus anthracis, Burkholderia mallei/pseudomallei, Coxiella burnetii, Francisella tularensis, and Yersinia pestis using real time PCR assays. Chemi...
Moran, Gary P
Because most fungi have evolved to be free-living in the environment and because the infections they cause are usually opportunistic in nature, it is often difficult to identify specific traits that contribute to fungal pathogenesis. In recent years, there has been a surge in the number of sequenced genomes of human fungal pathogens, and comparison of these sequences has proved to be an excellent resource for exploring commonalities and differences in how these species interact with their hosts. In order to survive in the human body, fungi must be able to adapt to new nutrient sources and environmental stresses. Therefore, genes involved in carbohydrate and amino acid metabolism and transport and genes encoding secondary metabolites tend to be overrepresented in pathogenic species (e.g., Aspergillus fumigatus). However, it is clear that human commensal yeast species such as Candida albicans have also evolved a range of specific factors that facilitate direct interaction with host tissues. The evolution of virulence across the human pathogenic fungi has occurred largely through very similar mechanisms. One of the most important mechanisms is gene duplication and the expansion of gene families, particularly in subtelomeric regions. Unlike the case for prokaryotic pathogens, horizontal transfer of genes between species and other genera does not seem to have played a significant role in the evolution of fungal virulence. New sequencing technologies promise the prospect of even greater numbers of genome sequences, facilitating the sequencing of multiple genomes and transcriptomes within individual species, and will undoubtedly contribute to a deeper insight into fungal pathogenesis.
Full Text Available We dedicated this review to discuss Helicobacter pylori as one of the latest identified bacterial pathogens in humans and whether its role is mainly as a pathogen or a commensal. Diseases associated with this bacterium were highly prevalent during the 19th century and gradually have declined. Most diseases associated with H. pylori occurred in individuals older than 40 years of age. However, acquisition of H. pylori occurs mainly in young children inside the family setting. Prevalence and incidence of H. pylori has had a dramatic change in the last part of the 20th century and beginning of the 21th century. In developed countries there is a clear interruption of transmission and the lowest prevalence is observed in children younger than 10 years in these countries. A similar decline is observed but not at the same level in developing countries. Here we discuss the impact of the presence or absence of H. pylori in the health status of humans. We also discuss whether it is necessary or not to establish H. pylori eradication programs on light of the current decline in H. pylori prevalence.
Full Text Available Background: Occupational exposure to pathogens forms a major concern among nurses, the largest team among healthcare professionals. Unfortunately, international literature marks high rates of occupational exposure to pathogens among nurses. Data from these studies allow to the implementation of prevention programs to avoid such incidences.Aim:To assess the prevalence of Cypriot nurses’ occupational exposure to pathogens as well as their reporting behaviour following such incidences.Methodology: A cross sectional survey has been conducted among a convenience sample of 577 nurses, during March and May 2010.Results: Our analysis demonstrated that almost half of Cypriot nurses (48.4% had at least one incidence of occupational exposure to pathogens, with more than 20% of the exposed nurses having been exposed via more than one mode. The majority of them have made a report of the incident, according to the policy of their hospital. Main reasons for not reporting such a critical incident included being too busy and forgetfulness.Conclusions: The results indicate that exposure to pathogens among Cypriot nurses is high, a fact that puts them into danger for acquiring an infection. A risk management program should be implemented to reduce such incidents.
Hirasawa, Akira; Imoto, Issei; Naruto, Takuya; Akahane, Tomoko; Yamagami, Wataru; Nomura, Hiroyuki; Masuda, Kiyoshi; Susumu, Nobuyuki; Tsuda, Hitoshi; Aoki, Daisuke
Pathogenic germline BRCA1 , BRCA2 ( BRCA1/2 ), and several other gene variants predispose women to primary ovarian, fallopian tube, and peritoneal carcinoma (OC), although variant frequency and relevance information is scarce in Japanese women with OC. Using targeted panel sequencing, we screened 230 unselected Japanese women with OC from our hospital-based cohort for pathogenic germline variants in 75 or 79 OC-associated genes. Pathogenic variants of 11 genes were identified in 41 (17.8%) women: 19 (8.3%; BRCA1 ), 8 (3.5%; BRCA2 ), 6 (2.6%; mismatch repair genes), 3 (1.3%; RAD51D ), 2 (0.9%; ATM ), 1 (0.4%; MRE11A ), 1 ( FANCC ), and 1 ( GABRA6 ). Carriers of BRCA1/2 or any other tested gene pathogenic variants were more likely to be diagnosed younger, have first or second-degree relatives with OC, and have OC classified as high-grade serous carcinoma (HGSC). After adjustment for these variables, all 3 features were independent predictive factors for pathogenic variants in any tested genes whereas only the latter two remained for variants in BRCA1/2 . Our data indicate similar variant prevalence in Japanese patients with OC and other ethnic groups and suggest that HGSC and OC family history may facilitate genetic predisposition prediction in Japanese patients with OC and referring high-risk patients for genetic counseling and testing.
Mrljak, Vladimir; Kuleš, Josipa; Mihaljević, Željko; Torti, Marin; Gotić, Jelena; Crnogaj, Martina; Živičnjak, Tatjana; Mayer, Iva; Šmit, Iva; Bhide, Mangesh; Barić Rafaj, Renata
Vector-borne pathogens (VBPs) are a group of globally extended and quickly spreading pathogens that are transmitted by various arthropod vectors. The aim of the present study was to investigate the seroprevalence against Babesia canis, Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, Leishmania infantum, Dirofilaria immitis, and Ehrlichia canis in dogs in Croatia. We investigated 435 randomly selected apparently healthy dogs in 13 different locations of Croatia for antibodies to B. canis by indirect immunofluorescence using a commercial IFA IgG Antibody Kit. All samples were also tested for qualitative detection of D. immitis antigen and for antibodies to A. phagocytophilum, B. burgdorferi sensu lato, L. infantum, and E. canis with two point-of-care assays. Overall, 112 dogs (25.74%, 95% confidence interval [CI] 21.70-30.12) were serologically positive for one or more of the pathogens. B. canis was the most prevalent pathogen (20.00%, 95% CI 16.34-24.07), followed by A. phagocytophilum (6.21%, 95% CI 4.12-8.90), L. infantum, (1.38%, 95% CI 0.51-2.97), and B. burgdorferi sensu lato (0.69%, 95% CI 0.01-2.00). The lowest seroprevalence was for D. immitis and E. canis (0.46%, 95% CI 0.01-1.65). Coinfection was determined in 12 dogs (2.76%, 95% CI 1.43-4.77), of which 10 were positive to two pathogens (7 with B. canis and A. phagocytophilum and 1 B. canis with B. burgdorferi sensu lato or L. infantum or E. canis). One dog was positive to three pathogens and another dog to four pathogens. Seroprevalence for babesia was age, breed, and lifestyle/use dependent. Purebred dogs had almost half the chance of developing disease than crossbred (OR = 0.58, p Croatia. Some of these VBPs are zoonotic and represent a potential risk to public health.
Wang, Ya Jing; Qin, Yun; Guix Vallverdú, Roger; Maldonado García, Jaime; Sun, Wei; Li, Shengli; Cao, Zhijun
The objectives of this study were to estimate the herd prevalence of major mastitis pathogens in bulk tank milk (BTM) in China dairy herds, to determine the relationship between the presence of mastitis pathogens and bulk tank milk somatic cell counts (BTSCC), and to investigate the impact of different dairy cattle farming modes and region on bacterial species. BTM samples collected from 894 dairy herds in China were examined for the presence of mastitis pathogens. The Flinders Technology Associates (FTA) cards were used for BTM sample collection, storage, and transportation and bacterial DNA amplification by real-time PCR. Among contagious pathogens, Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae were detected in 50.1, 92.2, and 72.3% of the 894 BTM samples, respectively. Among environmental pathogens, E. coli, Streptococcus uberis, Enterococcus spp., Klebsiella spp., Serratia marcescens, Corynebacterium bovis, and Arcanobacterium pyogenes were detected in 28.6, 8.9, 35.7, 20.0, 1.3, 17.0, and 67.2% of the BTM samples, respectively. Staphylococcal β-lactamase gene was detected in 61.7% of the BTM samples. The presence of Staphylococcus aureus and Arcanobacterium pyogenes were significantly associated with high BTSCC, respectively. Significant differences were found in presence of Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae in BTM sampled from the small household farms, dairy-farming communities, and large-scaled dairy farms. There were significant differences in the presence of Streptococcus agalactiae, Streptococcus dysgalactiae, Arcanobacterium pyogenes, staphylococcal β-lactamase gene, Staphylococcus spp., Klebsiella spp., Enterococcus spp., and Streptococcus uberis in BTM among Inner Mongolia, Heilongjiang, and Hebei province. In conclusion, contagious mammary pathogens are predominated among pathogens in BTM samples in China. PMID:27187065
Panayidou, Stavria; Ioannidou, Eleni; Apidianakis, Yiorgos
Drosophila has been the invertebrate model organism of choice for the study of innate immune responses during the past few decades. Many Drosophila–microbe interaction studies have helped to define innate immunity pathways, and significant effort has been made lately to decipher mechanisms of microbial pathogenesis. Here we catalog 68 bacterial, fungal, and viral species studied in flies, 43 of which are relevant to human health. We discuss studies of human pathogens in flies revealing not only the elicitation and avoidance of immune response but also mechanisms of tolerance, host tissue homeostasis, regeneration, and predisposition to cancer. Prominent among those is the emerging pattern of intestinal regeneration as a defense response induced by pathogenic and innocuous bacteria. Immunopathology mechanisms and many microbial virulence factors have been elucidated, but their relevance to human health conventionally necessitates validation in mammalian models of infection. PMID:24398387
Paudyal, Narayan; Anihouvi, Victor; Hounhouigan, Joseph; Matsheka, Maitshwarelo Ignatius; Sekwati-Monang, Bonno; Amoa-Awua, Wisdom; Atter, Amy; Ackah, Nina Bernice; Mbugua, Samuel; Asagbra, Agnes; Abdelgadir, Warda; Nakavuma, Jesca; Jakobsen, Mogens; Fang, Weihuan
Food safety information in the African region is insufficient and fragmented due to lack of surveillance, documentation and reporting, thereby resulting in inefficient utilization of resources, duplication of activities, and lack of synergy among the countries of the region. This paper reviews the prevalence of foodborne pathogens in seven African countries (Benin, Botswana, Ghana, Kenya, Nigeria, Sudan and Uganda) from papers in regional or international journals published between January 2000 and December 2015. One hundred and sixteen publications that dealt with food microbiology were reviewed for general analysis, while 66 papers on contamination of pathogenic bacteria were used for meta-analysis of prevalence. The food items were split into two categories: raw foods and ready-to-eat (RTE) foods (including street food and beverages) for meta-analysis. Majority of the reviewed studies (67.2%, 78/116) dealt with food of animal origin: 38.8% for meat and eggs, 17.2% for dairy products and 11.2% for aquatic products. Only 8.6% examined foods of plant origin (fruits and vegetables). The remaining 24.1% was the composite RTE food and beverages. Enterobacteriaceae, Escherichia coli, Salmonella, Staphylococcus aureus and Listeria monocytogenes were the most frequently reported organisms in those studies. Although the data were highly heterogeneous, a striking feature is high prevalence of the major pathogens in RTE foods, almost as high as in raw foods. E. coli averaged at 37.6% in raw foods and 31.6% in RTE foods. The corresponding prevalence for Salmonella was 19.9% vs 21.7%; S. aureus, 27.8% vs 25.1% and L. monocytogenes, 19.5% vs 6.7%. The average prevalence of foodborne pathogens in these countries was 34.2% (29.0-39.3%). Differences in food types as well as non-uniform protocols for sampling and identification might have contributed to high heterogeneity (I 2 >97%) although some high prevalence data could be factual with extensive varieties of raw and RTE foods
Dan, Sorin Daniel; Tăbăran, Alexandra; Mihaiu, Liora; Mihaiu, Marian
The occurrence of pathogenic strains in poultry meat is of growing concern in Romania. Another problem found on a global level is the continuous increase of antimicrobial resistance in bacteria isolated from food. This study aimed to evaluate the prevalence of pathogenic bacteria in poultry carcasses obtained in Romania in 2012-2013 and to reveal the most prevalent patterns of antimicrobial resistance in the isolated strains. A total of 144 broiler chicken carcasses were evaluated according to classical microbiological methods. The DNA was extracted from the bacterial colonies and the resistance genes were identified by PCR. In 2012, 47.2% of the samples revealed at least one of the following bacteria: Campylobacter jejuni (9.72%; n = 7), Salmonella enterica serotype Enteritidis (4.17%; n = 3), Listeria monocytogenes (15.28%; n = 11), and Escherichia coli (16.67%; n = 12). In 2013, the number of positive samples of pathogenic bacteria decreased, although Campylobacter jejuni was isolated in a higher percentage (20.8% vs. 9.72%). The percentage of multidrug-resistant (MDR) bacteria was high (23%); the most prevalent pattern included resistance to tetracycline, sulfonamides, and quinolones/fluoroquinolones. All the resistant Salmonella and E. coli strains were tested for the presence of characteristic resistance genes (Kn, bla(TEM), tetA, tetB, tetG, DfrIa, aadA1a, Sul) and revealed that these isolates represent an important reservoir in the spread of this phenomenon. Our findings suggest that Romania urgently needs an integrated surveillance system within the entire chain, for drug-resistant pathogens isolated from poultry meat.
Newkirk, M M; Rioux, J D
The human antibody response to foreign pathogens is generated to a relatively small number of target surface proteins and carbohydrates that nonetheless have an extensive array of epitopes. The study of human monoclonal antibodies to different pathogens shows that there are a diversity of mechanisms used to generate a sufficient repertoire of antibodies to combat the invading pathogens. Although many different immunoglobulin gene elements are used to construct the anti-pathogen response, some elements are used more often than would be expected if all elements were used randomly. For example, the immune response to Haemophilus influenzae polysaccharide appears to be quite narrow, being restricted primarily to a specific heavy-chain gene, 3-15, and a lambda light-chain family II member, 4A. In contrast, for the immune response to cytomegalovirus proteins, a wider group of gene elements is needed. It is also surprising that despite an investigator bias for IgG- rather than IgM-secreting immortal B cells (because of their high affinity and neutralizing abilities), 26% of light chains and 13% of heavy chains showed a very low level of somatic mutation, equivalent to an IgM molecule that has not undergone affinity maturation. Although some highly mutated IgG molecules are present in the anti-pathogen response, most of the monoclonal antibodies specific for viruses or bacteria have a level of somatic hypermutation similar to that of the adult IgM repertoire. A number of studies have shown that there are similarities in the antibody responses to pathogens and to self (autoantibodies).(ABSTRACT TRUNCATED AT 250 WORDS)
Full Text Available Bacteria in the genus Vibrio produce extracellular proteolytic enzymes to obtain nutrients via digestion of various protein substrates. However, the enzymes secreted by human pathogenic species have been documented to modulate the bacterial virulence. Several species including Vibrio cholerae and V. vulnificus are known to produce thermolysin-like metalloproteases termed vibriolysin. The vibriolysin from V. vulnificus, a causative agent of serious systemic infection, is a major toxic factor eliciting the secondary skin damage characterized by formation of the hemorrhagic brae. The vibriolysin from intestinal pathogens may play indirect roles in pathogenicity because it can activate protein toxins and hemagglutinin by the limited proteolysis and can affect the bacterial attachment to or detachment from the intestinal surface by degradation of the mucus layer. Two species causing wound infections, V. alginolyticus and V. parahaemolyticus, produce another metalloproteases so-called collagenases. Although the detailed pathological roles have not been studied, the collagenase is potent to accelerate the bacterial dissemination through digestion of the protein components of the extracellular matrix. Some species produce cymotrypsin-like serine proteases, which may also affect the bacterial virulence potential. The intestinal pathogens produce sufficient amounts of the metalloprotease at the small intestinal temperature; however, the metalloprotease production by extra-intestinal pathogens is much higher around the body surface temperature. On the other hand, the serine protease is expressed only in the absence of the metalloprotease.
Full Text Available Bumblebees provide pollination services not only to wildflowers but also to economically important crops. In the context of the global decline of pollinators, there is an increasing interest in determining the pathogen diversity of bumblebee species. In this work, wild bumblebees of the species Bombus terrestris and Bombus pascuorum from northern and southern Spain were molecularly screened to detect and estimate prevalence of pathogens. One third of bumblebees were infected: while viruses only infected B. pascuorum, B. terrestris was infected by Apicystis bombi, Crithidia bombi and Nosema bombi. Ecological differences between host species might affect the success of the pathogens biological cycle and consequently infection prevalence. Furthermore, sex of the bumblebees (workers or males, sampling area (north or south and altitude were important predictors of pathogen prevalence. Understanding how these factors affect pathogens distribution is essential for future conservation of bumblebee wild populations.
Cagliani, Rachele; Sironi, Manuela
Infectious diseases and epidemics have always accompanied and characterized human history, representing one of the main causes of death. Even today, despite progress in sanitation and medical research, infections are estimated to account for about 15% of deaths. The hypothesis whereby infectious diseases have been acting as a powerful selective pressure was formulated long ago, but it was not until the availability of large-scale genetic data and the development of novel methods to study molecular evolution that we could assess how pervasively infectious agents have shaped human genetic diversity. Indeed, recent evidences indicated that among the diverse environmental factors that acted as selective pressures during the evolution of our species, pathogen load had the strongest influence. Beside the textbook example of the major histocompatibility complex, selection signatures left by pathogen-exerted pressure can be identified at several human loci, including genes not directly involved in immune response. In the future, high-throughput technologies and the availability of genetic data from different populations are likely to provide novel insights into the evolutionary relationships between the human host and its pathogens. Hopefully, this will help identify the genetic determinants modulating the susceptibility to infectious diseases and will translate into new treatment strategies.
Stirling, J; Griffith, M; Blair, I; Cormican, M; Dooley, J S G; Goldsmith, C E; Glover, S G; Loughrey, A; Lowery, C J; Matsuda, M; McClurg, R; McCorry, K; McDowell, D; McMahon, A; Cherie Millar, B; Nagano, Y; Rao, J R; Rooney, P J; Smyth, M; Snelling, W J; Xu, J; Moore, J E
Faecal prevalence of gastrointestinal bacterial pathogens, including Campylobacter, Escherichia coli O157:H7, Salmonella, Shigella, Yersinia, as well as Arcobacter, were examined in 317 faecal specimens from 44 animal species in Belfast Zoological Gardens, during July-September 2006. Thermophilic campylobacters including Campylobacter jejuni, Campylobacter coli and Campylobacter lari, were the most frequently isolated pathogens, where members of this genus were isolated from 11 animal species (11 of 44; 25%). Yersinia spp. were isolated from seven animal species (seven of 44; 15.9%) and included, Yersinia enterocolitica (five of seven isolates; 71.4%) and one isolate each of Yersinia frederiksenii and Yersinia kristensenii. Only one isolate of Salmonella was obtained throughout the entire study, which was an isolate of Salmonella dublin (O 1,9,12: H g, p), originating from tiger faeces after enrichment. None of the animal species found in public contact areas of the zoo were positive for any gastrointestinal bacterial pathogens. Also, water from the lake in the centre of the grounds, was examined for the same bacterial pathogens and was found to contain C. jejuni. This study is the first report on the isolation of a number of important bacterial pathogens from a variety of novel host species, C. jejuni from the red kangaroo (Macropus rufus), C. lari from a maned wolf (Chrysocyon brachyurus), Y. kristensenii from a vicugna (Vicugna vicugna) and Y. enterocolitica from a maned wolf and red panda (Ailurus fulgens). In conclusion, this study demonstrated that the faeces of animals in public contact areas of the zoo were not positive for the bacterial gastrointestinal pathogens examined. This is reassuring for the public health of visitors, particularly children, who enjoy this educational and recreational resource.
Edelman Daniel C
Full Text Available Abstract In 1994, Chang and Moore reported on the latest of the gammaherpesviruses to infect humans, human herpesvirus 8 (HHV-8 1. This novel herpesvirus has and continues to present challenges to define its scope of involvement in human disease. In this review, aspects of HHV-8 infection are discussed, such as, the human immune response, viral pathogenesis and transmission, viral disease entities, and the virus's epidemiology with an emphasis on HHV-8 diagnostics.
Full Text Available Group C streptococci (GCS are livestock pathogens and they often cause zoonotic diseases in humans. They are Gram-positive, in mostly β-hemolytic and facultative anaerobes. Because of their close evolutionary kinship with group A streptococci (GAS, GCS share many common virulence factors with GAS and cause a similar range of diseases. Due to the exchange of genetic material with GAS, GCS belong to bacteria that are difficult to be distinguished from group A streptococci; GCS are often treated in microbiological diagnostics as contamination of the culture. This report focuses mainly on the pathogenicity of virulent species of GCS and their association with human diseases. The condition that is most frequently quoted is pharyngitis. In this paper, the virulence factors have also been mentioned and an interesting link has been made between GCS and the pathogenesis of rheumatic diseases among the native people of India and Aboriginal populations.
Firew Kassa Esho
Full Text Available The production and consumption of domestic natural cheese in Japan is increasing year by year. More than ninety percent of domestic natural cheese is produced in Hokkaido region of Japan, while information on its quality and safety related to foodborne pathogens is limited. To assess the microbiological safety of domestic natural cheese, a total of 126 natural cheese samples produced in Hokkaido were collected from December, 2012, to July, 2013. In addition to standard plate count (SPC and coliform counts, the prevalence study of three pathogens (Listeria monocytogenes, pathogenic Escherichia coli, and Salmonella spp. was performed on each sample. Real-time PCR and matrix-assisted laser desorption-ionization time-of-flight mass spectrometer methods were employed for identification of presumptive pathogens. Coliform was detected in 25 samples (19.8% with a minimum of 25 cfu/g and a maximum of more than 3.0 × 106 cfu/g. Salmonella spp. and L. monocytogenes were not isolated from any of the samples. Only one sample (0.80% showed positive PCR amplification for ipaH gene suggesting possible contamination of enteroinvasive E. coli or Shigella in this product. Overall results indicate that natural cheeses produced in Hokkaido region were satisfactory microbiological quality according to existing international standards.
Full Text Available Yersiniosis is the third most frequently reported zoonosis in the European Union and Yersinia enterocolitica is the most common species causing human infections. Pigs are assumed to be the main reservoir of human pathogenic Y. enterocolitica with the presence of bacteria mainly in the tonsils and intestinal content. Undercooked pork and pork products have been suggested as the primary source of human yersiniosis. Nevertheless, data on the prevalence of pathogenic Y. enterocolitica in foodstuffs including pork products are very limited. A molecular based method (real time PCR targeting the ompF gene (detection of Yersinia genus and the ail gene (a chromosomally located virulence marker of Y. enterocolitica was used to determine the prevalence of pathogenic Y. enterocolitica in minced meat and edible pork offal at the retail level in the Czech Republic. A total of 50 pig tongues, 50 pig hearts, and 93 samples of minced meat containing pork were purchased at nine retail outlets in Brno. High detection rates of Yersinia spp. were found in all types of samples (pig tongues, 80.0%; pig hearts, 40.0%; and minced meat, 55.9%. The highest prevalence of pathogenic Y. enterocolitica was found in pig tongues (40.0%, followed by pig hearts (18.0% and minced meat samples (17.2%. Although from the point of view of food safety the merely molecular detection of DNA of the pathogenic bacteria could represent a false positive result, our results indicate the presence of pathogenic Y. enterocolitica in raw pork products at the retail level in the Czech Republic, which may pose a risk of consumer infection. Sufficient heat treatment and prevention of cross-contamination during preparation of food in the kitchen should be recommended.
Isaacs, Charles E
Breast-feeding can reduce the incidence and the severity of gastrointestinal and respiratory infections in the suckling neonate by providing additional protective factors to the infant's mucosal surfaces. Human milk provides protection against a broad array of infectious agents through redundancy. Protective factors in milk can target multiple early steps in pathogen replication and target each step with more than one antimicrobial compound. The antimicrobial activity in human milk results from protective factors working not only individually but also additively and synergistically. Lipid-dependent antimicrobial activity in milk results from the additive activity of all antimicrobial lipids and not necessarily the concentration of one particular lipid. Antimicrobial milk lipids and peptides can work synergistically to decrease both the concentrations of individual compounds required for protection and, as importantly, greatly reduce the time needed for pathogen inactivation. The more rapidly pathogens are inactivated the less likely they are to establish an infection. The total antimicrobial protection provided by human milk appears to be far more than can be elucidated by examining protective factors individually.
Full Text Available Infectious diarrhoea is associated with a modification of the intestinal microflora and colonization of pathogenic bacteria. Tests were performed for seven probiotic yeast strains of Saccharomyces cerevisiae var. boulardii, designated for the prevention and treatment of diarrhoea. To check their possible effectiveness against diarrhoea of different etiologies, the activity against a variety of human pathogenic or opportunistic bacteria was investigated in vitro. In mixed cultures with S. cerevisiae var. boulardii, a statistically significant reduction was observed in the number of cells of Listeria monocytogenes, Pseudomonas aeruginosa and Staphylococcus aureus, by even 55.9 % in the case of L. monocytogenes compared with bacterial monocultures. The influence of yeasts was mostly associated with the shortening of the bacterial lag phase duration, more rapid achievement of the maximum growth rates, and a decrease by 4.4–57.1 % (L. monocytogenes, P. aeruginosa, or an increase by 1.4–70.6 % (Escherichia coli, Enterococcus faecalis, Salmonella Typhimurium in the exponential growth rates. Another issue included in the research was the ability of S. cerevisiae var. boulardii to bind pathogenic bacteria to its cell surface. Yeasts have shown binding capacity of E. coli, S. Typhimurium and additionally of S. aureus, Campylobacter jejuni and E. faecalis. However, no adhesion of L. monocytogenes and P. aeruginosa to the yeast cell wall was noted. The probiotic activity of S. cerevisiae var. boulardii against human pathogens is related to a decrease in the number of viable and active cells of bacteria and the binding capacity of yeasts. These processes may limit bacterial invasiveness and prevent bacterial adherence and translocation in the human intestines.
Catharina de Paula Oliveira Cavalcanti Soares
Full Text Available Objective: to determine the seroprevalence of Brucella spp in humans.Method: this is an observational study, developed with 455 individuals between 18 and 64 years old, who use the Estratégia de Saúde da Família (Brazil's family health strategy. The serum samples of volunteers underwent buffered acid antigen tests, such as screening, agar gel immunodiffusion and slow seroagglutination test in tubes and 2-Mercaptoethanol.Results: among the samples, 1.98% has responded to buffered-acid antigen, 2.85% to agar gel immunodiffusion test and 1.54% to the slow seroagglutination tests on tubes/2-Mercaptoethanol. The prevalence of Brucella spp was 4.4%, represented by the last two tests.Conclusion: the results of this research suggest that the studied population is exposed to Brucella spp infection.
Christopher A Desjardins
Full Text Available Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced the genomes of two strains of Paracoccidioides brasiliensis (Pb03 and Pb18 and one strain of Paracoccidioides lutzii (Pb01. These genomes range in size from 29.1 Mb to 32.9 Mb and encode 7,610 to 8,130 genes. To enable genetic studies, we mapped 94% of the P. brasiliensis Pb18 assembly onto five chromosomes. We characterized gene family content across Onygenales and related fungi, and within Paracoccidioides we found expansions of the fungal-specific kinase family FunK1. Additionally, the Onygenales have lost many genes involved in carbohydrate metabolism and fewer genes involved in protein metabolism, resulting in a higher ratio of proteases to carbohydrate active enzymes in the Onygenales than their relatives. To determine if gene content correlated with growth on different substrates, we screened the non-pathogenic onygenale Uncinocarpus reesii, which has orthologs for 91% of Paracoccidioides metabolic genes, for growth on 190 carbon sources. U. reesii showed growth on a limited range of carbohydrates, primarily basic plant sugars and cell wall components; this suggests that Onygenales, including dimorphic fungi, can degrade cellulosic plant material in the soil. In addition, U. reesii grew on gelatin and a wide range of dipeptides and amino acids, indicating a preference for proteinaceous growth substrates over carbohydrates, which may enable these fungi to also degrade animal biomass. These capabilities for degrading plant and animal substrates suggest a duality in lifestyle that could enable pathogenic
Resende, Juliana Alves; Silva, Vânia Lúcia; de Oliveira, Tamara Lopes Rocha; de Oliveira Fortunato, Samuel; da Costa Carneiro, Jailton; Otenio, Marcelo Henrique; Diniz, Cláudio Galuppo
Anaerobic digestion figures as a sustainable alternative to avoid discharge of cattle manure in the environment, which results in biogas and biofertilizer. Persistence of potentially pathogenic and drug-resistant bacteria during anaerobic digestion of cattle manure was evaluated. Selective cultures were performed for enterobacteria (ENT), non-fermenting Gram-negative rods (NFR) and Gram-positive cocci (GPC). Antimicrobial susceptibility patterns were determined and a decay of all bacterial groups was observed after 60days. Multidrug-resistant bacteria were detected both the influent and effluent. GPC, the most prevalent group was highly resistant against penicillin and levofloxacin, whereas resistance to ampicillin, ampicillin-sulbactam and chloramphenicol was frequently observed in the ENT and NFR groups. The data point out the need of discussions to better address management of biodigesters and the implementation of sanitary and microbiological safe treatments of animal manures to avoid consequences to human, animal and environmental health. Copyright © 2013 Elsevier Ltd. All rights reserved.
Tryland, M; Nesbakken, T; Robertson, L; Grahek-Ogden, D; Lunestad, B T
Only a few countries worldwide hunt seals and whales commercially. In Norway, hooded and harp seals and minke whales are commercially harvested, and coastal seals (harbour and grey seals) are hunted as game. Marine mammal meat is sold to the public and thus included in general microbiological meat control regulations. Slaughtering and dressing of marine mammals are performed in the open air on deck, and many factors on board sealing or whaling vessels may affect meat quality, such as the ice used for cooling whale meat and the seawater used for cleaning, storage of whale meat in the open air until ambient temperature is reached, and the hygienic conditions of equipment, decks, and other surfaces. Based on existing reports, it appears that meat of seal and whale does not usually represent a microbiological hazard to consumers in Norway, because human disease has not been associated with consumption of such foods. However, as hygienic control on marine mammal meat is ad hoc, mainly based on spot-testing, and addresses very few human pathogens, this conclusion may be premature. Additionally, few data from surveys or systematic quality control screenings have been published. This review examines the occurrence of potential human pathogens in marine mammals, as well as critical points for contamination of meat during the slaughter, dressing, cooling, storage and processing of meat. Some zoonotic agents are of particular relevance as foodborne pathogens, such as Trichinella spp., Toxoplasma gondii, Salmonella and Leptospira spp. In addition, Mycoplasma spp. parapoxvirus and Mycobacterium spp. constitute occupational risks during handling of marine mammals and marine mammal products. Adequate training in hygienic procedures is necessary to minimize the risk of contamination on board, and acquiring further data is essential for obtaining a realistic assessment of the microbiological risk to humans from consuming marine mammal meat.
Full Text Available The importance of tick-borne diseases is increasing all over the world, including Turkey. The tick-borne disease outbreaks reported in recent years and the abundance of tick species and the existence of suitable habitats increase the importance of studies related to the epidemiology of ticks and tick-borne pathogens in Turkey. The aim of this study was to investigate the presence of and to determine the infection rates of some tick-borne pathogens, including Babesia spp., Borrelia burgdorferi sensu lato and spotted fever group rickettsiae in the ticks removed from humans in different parts of Ankara.A total of 169 ticks belonging to the genus Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus were collected by removing from humans in different parts of Ankara. Ticks were molecularly screened for Babesia spp., Borrelia burgdorferi sensu lato and spotted fever group rickettsiae by PCR and sequencing analysis. We detected 4 Babesia spp.; B. crassa, B. major, B. occultans and B. rossi, one Borrelia spp.; B. burgdorferi sensu stricto and 3 spotted fever group rickettsiae; R. aeschlimannii, R. slovaca and R. hoogstraalii in the tick specimens analyzed. This is the report showing the presence of B. rossi in a region that is out of Africa and in the host species Ha. parva. In addition, B. crassa, for which limited information is available on its distribution and vector species, and B. occultans, for which no conclusive information is available on its presence in Turkey, were identified in Ha. parva and H. marginatum, respectively. Two human pathogenic rickettsia species (R. aeschlimannii and R. slovaca were detected with a high prevalence in ticks. Additionally, B. burgdorferi sensu stricto was detected in unusual tick species (H. marginatum, H. excavatum, Hyalomma spp. (nymph and Ha. parva.This study investigates both the distribution of several tick-borne pathogens affecting humans and animals, and the presence of new tick-borne pathogens in Turkey
Ximenes, Eduardo; Hoagland, Lori; Ku, Seockmo; Li, Xuan; Ladisch, Michael
Fresh produce, viewed as an essential part of a healthy life style is usually consumed in the form of raw or minimally processed fruits and vegetables, and is a potentially important source of food-borne human pathogenic bacteria and viruses. These are passed on to the consumer since the bacteria can form biofilms or otherwise populate plant tissues, thereby using plants as vectors to infect animal hosts. The life cycle of the bacteria in plants differs from those in animals or humans and results in altered physiochemical and biological properties (e.g., physiology, immunity, native microflora, physical barriers, mobility, and temperature). Mechanisms by which healthy plants may become contaminated by microorganisms, develop biofilms, and then pass on their pathogenic burden to people are explored in the context of hollow fiber microfiltration by which plant-derived microorganisms may be recovered and rapidly concentrated to facilitate study of their properties. Enzymes, when added to macerated plant tissues, hydrolyze or alter macromolecules that would otherwise foul hollow-fiber microfiltration membranes. Hence, microfiltration may be used to quickly increase the concentration of microorganisms to detectable levels. This review discusses microbial colonization of vegetables, formation and properties of biofilms, and how hollow fiber microfiltration may be used to concentrate microbial targets to detectable levels. The use of added enzymes helps to disintegrate biofilms and minimize hollow fiber membrane fouling, thereby providing a new tool for more time effectively elucidating mechanisms by which biofilms develop and plant tissue becomes contaminated with human pathogens. Biotechnol. Bioeng. 2017;114: 1403-1418. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Jenevaldo Barbosa da Silva
Full Text Available Although the largest buffalo herd in the occident is in the north region of Brazil, few studies have been conducted to assess the prevalence of selected parasitic diseases in buffalo herd. The present study was therefore conducted to investigate the epidemiological of Toxoplasma gondii, Neospora caninum, Anaplasma marginale, Babesia bigemina, and Babesia bovis in water buffaloes in the north region of Brazil. A total of 4796 buffalo blood samples were randomly collected from five provinces and simultaneously analyzed by the IFAT and ELISA. The serological prevalence of T. gondii and N. caninum was 41.3% and 55.5% in ELISA and 35.7% and 48.8% in IFAT, respectively. The overall prevalence of A. marginale, B. bovis, and B. bigemina was 63%, 25%, and 21% by ELISA and 50.0%, 22.5%, and 18.8% by IFAT, respectively. This study shows valuable information regarding the serological survey of selected bovine pathogens in water buffaloes in the north region of Brazil which will likely be very beneficial for the management and control programs of this disease.
Full Text Available Genetic recombination between pathogens derived from humans and livestock has the potential to create novel pathogen strains, highlighted by the influenza pandemic H1N1/09, which was derived from a re-assortment of swine, avian and human influenza A viruses. Here we investigated whether genetic recombination between subspecies of the protozoan parasite, Trypanosoma brucei, from humans and animals can generate new strains of human pathogen, T. b. rhodesiense (Tbr responsible for sleeping sickness (Human African Trypanosomiasis, HAT in East Africa. The trait of human infectivity in Tbr is conferred by a single gene, SRA, which is potentially transferable to the animal pathogen Tbb by sexual reproduction. We tracked the inheritance of SRA in crosses of Tbr and Tbb set up by co-transmitting genetically-engineered fluorescent parental trypanosome lines through tsetse flies. SRA was readily transferred into new genetic backgrounds by sexual reproduction between Tbr and Tbb, thus creating new strains of the human pathogen, Tbr. There was no evidence of diminished growth or transmissibility of hybrid trypanosomes carrying SRA. Although expression of SRA is critical to survival of Tbr in the human host, we show that the gene exists as a single copy in a representative collection of Tbr strains. SRA was found on one homologue of chromosome IV in the majority of Tbr isolates examined, but some Ugandan Tbr had SRA on both homologues. The mobility of SRA by genetic recombination readily explains the observed genetic variability of Tbr in East Africa. We conclude that new strains of the human pathogen Tbr are being generated continuously by recombination with the much larger pool of animal-infective trypanosomes. Such novel recombinants present a risk for future outbreaks of HAT.
Gibson, Wendy; Peacock, Lori; Ferris, Vanessa; Fischer, Katrin; Livingstone, Jennifer; Thomas, James; Bailey, Mick
Genetic recombination between pathogens derived from humans and livestock has the potential to create novel pathogen strains, highlighted by the influenza pandemic H1N1/09, which was derived from a re-assortment of swine, avian and human influenza A viruses. Here we investigated whether genetic recombination between subspecies of the protozoan parasite, Trypanosoma brucei, from humans and animals can generate new strains of human pathogen, T. b. rhodesiense (Tbr) responsible for sleeping sickness (Human African Trypanosomiasis, HAT) in East Africa. The trait of human infectivity in Tbr is conferred by a single gene, SRA, which is potentially transferable to the animal pathogen Tbb by sexual reproduction. We tracked the inheritance of SRA in crosses of Tbr and Tbb set up by co-transmitting genetically-engineered fluorescent parental trypanosome lines through tsetse flies. SRA was readily transferred into new genetic backgrounds by sexual reproduction between Tbr and Tbb, thus creating new strains of the human pathogen, Tbr. There was no evidence of diminished growth or transmissibility of hybrid trypanosomes carrying SRA. Although expression of SRA is critical to survival of Tbr in the human host, we show that the gene exists as a single copy in a representative collection of Tbr strains. SRA was found on one homologue of chromosome IV in the majority of Tbr isolates examined, but some Ugandan Tbr had SRA on both homologues. The mobility of SRA by genetic recombination readily explains the observed genetic variability of Tbr in East Africa. We conclude that new strains of the human pathogen Tbr are being generated continuously by recombination with the much larger pool of animal-infective trypanosomes. Such novel recombinants present a risk for future outbreaks of HAT.
da Silva Dantas, Alessandra; Day, Alison; Ikeh, Mélanie; Kos, Iaroslava; Achan, Beatrice; Quinn, Janet
Candida albicans is a major fungal pathogen of humans, causing approximately 400,000 life-threatening systemic infections world-wide each year in severely immunocompromised patients. An important fungicidal mechanism employed by innate immune cells involves the generation of toxic reactive oxygen species (ROS), such as superoxide and hydrogen peroxide. Consequently, there is much interest in the strategies employed by C. albicans to evade the oxidative killing by macrophages and neutrophils. Our understanding of how C. albicans senses and responds to ROS has significantly increased in recent years. Key findings include the observations that hydrogen peroxide triggers the filamentation of this polymorphic fungus and that a superoxide dismutase enzyme with a novel mode of action is expressed at the cell surface of C. albicans. Furthermore, recent studies have indicated that combinations of the chemical stresses generated by phagocytes can actively prevent C. albicans oxidative stress responses through a mechanism termed the stress pathway interference. In this review, we present an up-date of our current understanding of the role and regulation of oxidative stress responses in this important human fungal pathogen. PMID:25723552
Asit Ranjan Ghosh
Full Text Available The human body is host to a number of microbes occurring in various forms of host-microbe associations, such as commensals, mutualists, pathogens and opportunistic symbionts. While this association with microbes in certain cases is beneficial to the host, in many other cases it seems to offer no evident benefit or motive. The emergence and re-emergence of newer varieties of infectious diseases with causative agents being strains that were once living in the human system makes it necessary to study the environment and the dynamics under which this host microbe relationship thrives. The present discussion examines this interaction while tracing the origins of this association, and attempts to hypothesize a possible framework of selective pressures that could have lead microbes to inhabit mammalian host systems.
Full Text Available Research has found that contagion-minimizing behavioral tendencies are amplified in pathogen-prevalent regions. We investigated whether reactions to the “swine flu” outbreak of 2009 were stronger among East Asians than Westerners, populations residing in regions that now enjoy comparable advances in healthcare but that are characterized by relatively high and low historical pathogen prevalence, respectively. In a survey, East Asians reported greater concerns about infection, especially from foreigners. Analyses of international air travel data around the time of the outbreak provided corroborating evidence: Immediately following the outbreak, airports in the Asia-Pacific region lost more international traffic relative to their Western counterparts, and East Asian airlines reported greater declines in international traffic compared to Western airlines. These differences are unlikely to reflect objective threat posed by swine flu (whose casualties were concentrated in the Americas; rather, they appear to reflect culturally adapted behavioral patterns forged and sustained by regionally variable levels of pathogen prevalence.
Full Text Available Tick-borne diseases are increasing all over the word, including Turkey. The aim of this study was to determine the bacterial and protozoan vector-borne pathogens in ticks infesting humans in the Corum province of Turkey.From March to November 2014 a total of 322 ticks were collected from patients who attended the local hospitals with tick bites. Ticks were screened by real time-PCR and PCR, and obtained amplicons were sequenced. The dedected tick was belonging to the genus Hyalomma, Haemaphysalis, Rhipicephalus, Dermacentor and Ixodes. A total of 17 microorganism species were identified in ticks. The most prevalent Rickettsia spp. were: R. aeschlimannii (19.5%, R. slovaca (4.5%, R. raoultii (2.2%, R. hoogstraalii (1.9%, R. sibirica subsp. mongolitimonae (1.2%, R. monacensis (0.31%, and Rickettsia spp. (1.2%. In addition, the following pathogens were identified: Borrelia afzelii (0.31%, Anaplasma spp. (0.31%, Ehrlichia spp. (0.93%, Babesia microti (0.93%, Babesia ovis (0.31%, Babesia occultans (3.4%, Theileria spp. (1.6%, Hepatozoon felis (0.31%, Hepatozoon canis (0.31%, and Hemolivia mauritanica (2.1%. All samples were negative for Francisella tularensis, Coxiella burnetii, Bartonella spp., Toxoplasma gondii and Leishmania spp.Ticks in Corum carry a large variety of human and zoonotic pathogens that were detected not only in known vectors, but showed a wider vector diversity. There is an increase in the prevalence of ticks infected with the spotted fever group and lymphangitis-associated rickettsiosis, while Ehrlichia spp. and Anaplasma spp. were reported for the first time from this region. B. microti was detected for the first time in Hyalomma marginatum infesting humans. The detection of B. occultans, B. ovis, Hepatozoon spp., Theileria spp. and Hemolivia mauritanica indicate the importance of these ticks as vectors of pathogens of veterinary importance, therefore patients with a tick infestation should be followed for a variety of pathogens
Paudyal, Narayan; Anihouvi, Victor; Hounhouigan, Joseph
for general analysis, while 66 papers on contamination of pathogenic bacteria were used for meta-analysis of prevalence. The food items were split into two categories: raw foods and ready-to-eat (RTE) foods (including street food and beverages) for meta-analysis. Majority of the reviewed studies (67.2%, 78....../116) dealt with food of animal origin: 38.8% for meat and eggs, 17.2% for dairy products and 11.2% for aquatic products. Only 8.6% examined foods of plant origin (fruits and vegetables). The remaining 24.1% was the composite RTE food and beverages. Enterobacteriaceae, Escherichia coli, Salmonella......Food safety information in the African region is insufficient and fragmented due to lack of surveillance, documentation and reporting, thereby resulting in inefficient utilization of resources, duplication of activities, and lack of synergy among the countries of the region. This paper reviews...
Full Text Available In order to study the in situ effects of the agricultural landscape and exposure to pesticides on honey bee health, sixteen honey bee colonies were placed in four different agricultural landscapes. Those landscapes were three agricultural areas with varying levels of agricultural intensity (AG areas and one non-agricultural area (NAG area. Colonies were monitored for different pathogen prevalence and pesticide residues over a period of one year. RT-qPCR was used to study the prevalence of seven different honey bee viruses as well as Nosema sp. in colonies located in different agricultural systems with various intensities of soybean, corn, sorghum, and cotton production. Populations of the parasitic mite Varroa destructor were also extensively monitored. Comprehensive MS-LC pesticide residue analyses were performed on samples of wax, honey, foragers, winter bees, dead bees, and crop flowers for each apiary and location. A significantly higher level of varroa loads were recorded in colonies of the AG areas, but this at least partly correlated with increased colony size and did not necessarily result from exposure to pesticides. Infections of two viruses (deformed wing virus genotype a (DWVa and acute bee paralysis virus (ABPV and Nosema sp. varied among the four studied locations. The urban location significantly elevated colony pathogen loads, while AG locations significantly benefited and increased the colony weight gain. Cotton and sorghum flowers contained high concentrations of insecticide including neonicotinoids, while soybean and corn had less pesticide residues. Several events of pesticide toxicity were recorded in the AG areas, and high concentrations of neonicotinoid insecticides were detected in dead bees.
Full Text Available Abstract Background Human angiostrongyliasis is an emerging food-borne public health problem, with the number of cases increasing worldwide, especially in mainland China. Angiostrongylus cantonensis is the causative agent of this severe disease. However, little is known about the genetics and basic biology of A. cantonensis. Results A cDNA library of A. cantonensis fourth-stage larvae was constructed, and ~1,200 clones were sequenced. Bioinformatic analyses revealed 378 cDNA clusters, 54.2% of which matched known genes at a cutoff expectation value of 10-20. Of these 378 unique cDNAs, 168 contained open reading frames encoding proteins containing an average of 238 amino acids. Characterization of the functions of these encoded proteins by Gene Ontology analysis showed enrichment in proteins with binding and catalytic activity. The observed pattern of enzymes involved in protein metabolism, lipid metabolism and glycolysis may reflect the central nervous system habitat of this pathogen. Four proteins were tested for their immunogenicity using enzyme-linked immunosorbent assays and histopathological examinations. The specificity of each of the four proteins was superior to that of crude somatic and excretory/secretory antigens of larvae, although their sensitivity was relatively low. We further showed that mice immunized with recombinant cystatin, a product of one of the four cDNA candidate genes, were partially protected from A. cantonensis infection. Conclusion The data presented here substantially expand the available genetic information about the human pathogen A. cantonensis, and should be a significant resource for angiostrongyliasis researchers. As such, this work serves as a starting point for molecular approaches for diagnosing and controlling human angiostrongyliasis.
Fletcher, Jacqueline; Leach, Jan E; Eversole, Kellye; Tauxe, Robert
Recent efforts to address concerns about microbial contamination of food plants and resulting foodborne illness have prompted new collaboration and interactions between the scientific communities of plant pathology and food safety. This article provides perspectives from scientists of both disciplines and presents selected research results and concepts that highlight existing and possible future synergisms for audiences of both disciplines. Plant pathology is a complex discipline that encompasses studies of the dissemination, colonization, and infection of plants by microbes such as bacteria, viruses, fungi, and oomycetes. Plant pathologists study plant diseases as well as host plant defense responses and disease management strategies with the goal of minimizing disease occurrences and impacts. Repeated outbreaks of human illness attributed to the contamination of fresh produce, nuts and seeds, and other plant-derived foods by human enteric pathogens such as Shiga toxin-producing Escherichia coli and Salmonella spp. have led some plant pathologists to broaden the application of their science in the past two decades, to address problems of human pathogens on plants (HPOPs). Food microbiology, which began with the study of microbes that spoil foods and those that are critical to produce food, now also focuses study on how foods become contaminated with pathogens and how this can be controlled or prevented. Thus, at the same time, public health researchers and food microbiologists have become more concerned about plant-microbe interactions before and after harvest. New collaborations are forming between members of the plant pathology and food safety communities, leading to enhanced research capacity and greater understanding of the issues for which research is needed. The two communities use somewhat different vocabularies and conceptual models. For example, traditional plant pathology concepts such as the disease triangle and the disease cycle can help to define
Fletcher, Jacqueline; Leach, Jan E; Eversole, Kellye; Tauxe, Robert
Recent efforts to address concerns about microbial contamination of food plants and resulting foodborne illness have prompted new collaboration and interactions between the scientific communities of plant pathology and food safety. This article provides perspectives from scientists of both disciplines and presents selected research results and concepts that highlight existing and possible future synergisms for audiences of both disciplines. Plant pathology is a complex discipline that encompasses studies of the dissemination, colonization, and infection of plants by microbes such as bacteria, viruses, fungi, and oomycetes. Plant pathologists study plant diseases as well as host plant defense responses and disease management strategies with the goal of minimizing disease occurrences and impacts. Repeated outbreaks of human illness attributed to the contamination of fresh produce, nuts and seeds, and other plant-derived foods by human enteric pathogens such as Shiga toxin-producing Escherichia coli and Salmonella spp. have led some plant pathologists to broaden the application of their science in the past two decades, to address problems of human pathogens on plants (HPOPs). Food microbiology, which began with the study of microbes that spoil foods and those that are critical to produce food, now also focuses study on how foods become contaminated with pathogens and how this can be controlled or prevented. Thus, at the same time, public health researchers and food microbiologists have become more concerned about plant-microbe interactions before and after harvest. New collaborations are forming between members of the plant pathology and food safety communities, leading to enhanced research capacity and greater understanding of the issues for which research is needed. The two communities use somewhat different vocabularies and conceptual models. For example, traditional plant pathology concepts such as the disease triangle and the disease cycle can help to define
Shiningeni, Daphney; Chimwamurombe, Percy; Shilangale, Renatus; Misihairabgwi, Jane
To determine the prevalence of pathogenic bacteria in street vended ready-to-eat meats in Windhoek, Namibia, a total of 96 street vended ready to eat meat samples were evaluated. Prevalences of 42%, 52%, 15%, 6% and 83% were observed for Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Shigella and Enterobacteriaceae respectively, while the highest aerobic plate counts were 7.74 Log 10 cfu/g, 5.67 Log 10 cfu/g, 5.12 Log 10 cfu/g , 4.56 Log 10 cfu/g, 3.3 Log 10 cfu/g, 5.75 Log 10 cfu/g respectively. Unsatisfactory microbial levels were 32% for aerobic plate count, 26% for Enterobacteriaceae, 35% for Escherichia coli, 11% for Listeria monocytogenes, 7% for Staphylococcus aureus and 6% for Shigella. Salmonella was detected in 11% and 40% of samples from two suburbs. The unsatisfactory microbiological quality of some ready-to-eat meats necessitates the provision of training on food safety and hygiene to street vendors for consumer protection. Copyright © 2018 Elsevier Ltd. All rights reserved.
Mielczarek, Ewelina; Blaszkowska, Joanna
Trichomonas vaginalis, which colonizes the genitourinary tract of men and women, is a sexually transmitted parasite causing symptomatic or asymptomatic trichomoniasis. The host-parasite relationship is very complex, and clinical symptoms cannot likely be attributed to a single pathogenic effect. Among the many factors responsible for interactions between T. vaginalis and host tissues, contact-dependent and contact-independent mechanisms are important in pathogenicity, as is the immune response. This review focuses on the potential virulence properties of T. vaginalis and its role in female and male infertility. It highlights the association between T. vaginalis infection and serious adverse health consequences experienced by women, including infertility, preterm birth and low-birth-weight infants. Long-term clinical observations and results of in vitro experimental studies indicate that in men, trichomoniasis has been also associated with infertility through inflammatory damage to the genitourinary tract or interference with sperm function. These results contribute significantly to improving our knowledge of the role of parasitic virulence factors in the development of infection and its role in human infertility.
Palmieri, Valentina; Carmela Lauriola, Maria; Ciasca, Gabriele; Conti, Claudio; De Spirito, Marco; Papi, Massimiliano
Standing out as the new wonder bidimensional material, graphene oxide (GO) has aroused an exceptional interest in biomedical research by holding promise for being the antibacterial of future. First, GO possesses a specific interaction with microorganisms combined with a mild toxicity for human cells. Additionally, its antibacterial action seems to be directed to multiple targets in pathogens, causing both membranes mechanical injury and oxidative stress. Lastly, compared to other carbon materials, GO has easy and low-cost processing and is environment-friendly. This remarkable specificity and multi-targeting antibacterial activity come at a time when antibiotic resistance represents the major health challenge. Unfortunately, a comprehensive framework to understand how to effectively utilize this material against microorganisms is still lacking. In the last decade, several groups tried to define the mechanisms of interaction between GO flakes and pathogens but conflicting results have been reported. This review is focused on all the contradictions of GO antimicrobial properties in solution. Flake size, incubation protocol, time of exposure and species considered are examples of factors influencing results. These parameters will be summarized and analyzed with the aim of defining the causes of contradictions, to allow fast GO clinical application.
Fondrevez, M; Minvielle, B; Labbé, A; Houdayer, C; Rose, N; Esnault, E; Denis, M
The prevalence of pathogenic Yersinia enterocolitica in French slaughter-aged pigs was estimated by sampling 3120 pigs from 96 batches in 16 slaughterhouses from January 2010 to February 2011. Respectively, 36 batches (20 pigs/batch) and 60 batches (40 pigs/batch) were considered during the cold period and the warm period. Tonsils were swabbed before the chilling step. Pathogenic Y. enterocolitica was detected after enrichment in ITC and streaking on CIN and YeCM media. Typical isolates were confirmed as Y. enterocolitica and biotyped by biochemical tests as described in the ISO 10273:2003 method. Of the tested pigs, 13.7% (CI95% [10.1-17.3]) were found positive for pathogenic Y. enterocolitica and 74.3% (CI95% [64.8-83.8]) of the pig batches contained at least one positive pig. The percentage of positive pigs per batch was generally low; 60.3% of positive batches contained fewer than 5 positive pigs. The prevalence of the pathogen at the batch level remained unchanged throughout this one-year study, but the prevalence in pigs was significantly higher during the warm period than during the cold period. Biotype 4 was the most prevalent biotype among the 827 isolated strains (91.9% of the isolates), followed by biotype 3 (7.25% of the isolates). Six isolates were of biotype 5 and one of biotype 2. Biotype 4 was found in all the 16 participating slaughterhouses, biotype 3 in ten slaughterhouses and biotype 5 in four. This study provides valuable recent figures for the prevalence of pathogenic Y. enterocolitica in French pigs. It also highlights the seasonal aspect of the carriage of this pathogen by pigs, a pattern which differs from those in other countries. Copyright © 2014 Elsevier B.V. All rights reserved.
Santos, André L S; d'Avila-Levy, Claudia M; Elias, Camila G R; Vermelho, Alane B; Branquinha, Marta H
The present review provides an overview of recent discoveries concerning the immunological similarities between Phytomonas serpens, a tomato parasite, and human trypanosomatid pathogens, with special emphasis on peptidases. Leishmania spp. and Trypanosoma cruzi express peptidases that are well-known virulence factors, named leishmanolysin and cruzipain. P. serpens synthesizes two distinct classes of proteolytic enzymes, metallo- and cysteine-type peptidases, that share common epitopes with leishmanolysin and cruzipain, respectively. The leishmanolysin-like and cruzipain-like molecules from P. serpens participate in several biological processes including cellular growth and adhesion to the salivary glands of Oncopeltus fasciatus, a phytophagous insect experimental model. Since previous reports demonstrated that immunization of mice with P. serpens induced a partial protective immune response against T. cruzi, this plant trypanosomatid may be a suitable candidate for vaccine studies. Moreover, comparative approaches in the Trypanosomatidae family may be useful to understand kinetoplastid biology, biochemistry and evolution.
Kniemeyer, Olaf; Schmidt, André D; Vödisch, Martin; Wartenberg, Dirk; Brakhage, Axel A
Both fungi Candida albicans and Aspergillus fumigatus can cause a number of life-threatening systemic infections in humans. The commensal yeast C. albicans is one of the main causes of nosocomial fungal infectious diseases, whereas the filamentous fungus A. fumigatus has become one of the most prevalent airborne fungal pathogens. Early diagnosis of these fungal infections is challenging, only a limited number of antifungals for treatment are available, and the molecular details of pathogenicity are hardly understood. The completion of both the A. fumigatus and C. albicans genome sequence provides the opportunity to improve diagnosis, to define new drug targets, to understand the functions of many uncharacterised proteins, and to study protein regulation on a global scale. With the application of proteomic tools, particularly two-dimensional gel electrophoresis and LC/MS-based methods, a comprehensive overview about the proteins of A. fumigatus and C. albicans present or induced during environmental changes and stress conditions has been obtained in the past 5 years. However, for the discovery of further putative virulence determinants, more sensitive and targeted proteomic methods have to be applied. Here, we review the recent proteome data generated for A. fumigatus and C. albicans that are related to factors required for pathogenicity. Copyright © 2011 Elsevier GmbH. All rights reserved.
Barak, Jeri D; Schroeder, Brenda K
Bacterial food-borne pathogens use plants as vectors between animal hosts, all the while following the life cycle script of plant-associated bacteria. Similar to phytobacteria, Salmonella, pathogenic Escherichia coli, and cross-domain pathogens have a foothold in agricultural production areas. The commonality of environmental contamination translates to contact with plants. Because of the chronic absence of kill steps against human pathogens for fresh produce, arrival on plants leads to persistence and the risk of human illness. Significant research progress is revealing mechanisms used by human pathogens to colonize plants and important biological interactions between and among bacteria in planta. These findings articulate the difficulty of eliminating or reducing the pathogen from plants. The plant itself may be an untapped key to clean produce. This review highlights the life of human pathogens outside an animal host, focusing on the role of plants, and illustrates areas that are ripe for future investigation.
McIntyre, K. Marie; Setzkorn, Christian; Hepworth, Philip J.; Morand, Serge; Morse, Andrew P.; Baylis, Matthew
Disease or pathogen risk prioritisations aid understanding of infectious agent impact within surveillance or mitigation and biosecurity work, but take significant development. Previous work has shown the H-(Hirsch-)index as an alternative proxy. We present a weighted risk analysis describing infectious pathogen impact for human health (human pathogens) and well-being (domestic animal pathogens) using an objective, evidence-based, repeatable approach; the H-index. This study established the highest H-index European pathogens. Commonalities amongst pathogens not included in previous surveillance or risk analyses were examined. Differences between host types (humans/animals/zoonotic) in pathogen H-indices were explored as a One Health impact indicator. Finally, the acceptability of the H-index proxy for animal pathogen impact was examined by comparison with other measures. 57 pathogens appeared solely in the top 100 highest H-indices (1) human or (2) animal pathogens list, and 43 occurred in both. Of human pathogens, 66 were zoonotic and 67 were emerging, compared to 67 and 57 for animals. There were statistically significant differences between H-indices for host types (humans, animal, zoonotic), and there was limited evidence that H-indices are a reasonable proxy for animal pathogen impact. This work addresses measures outlined by the European Commission to strengthen climate change resilience and biosecurity for infectious diseases. The results include a quantitative evaluation of infectious pathogen impact, and suggest greater impacts of human-only compared to zoonotic pathogens or scientific under-representation of zoonoses. The outputs separate high and low impact pathogens, and should be combined with other risk assessment methods relying on expert opinion or qualitative data for priority setting, or could be used to prioritise diseases for which formal risk assessments are not possible because of data gaps. PMID:25136810
Hedayati, M T; Pasqualotto, A C; Warn, P A; Bowyer, P; Denning, D W
Aspergillus infections have grown in importance in the last years. However, most of the studies have focused on Aspergillus fumigatus, the most prevalent species in the genus. In certain locales and hospitals, Aspergillus flavus is more common in air than A. fumigatus, for unclear reasons. After A. fumigatus, A. flavus is the second leading cause of invasive aspergillosis and it is the most common cause of superficial infection. Experimental invasive infections in mice show A. flavus to be 100-fold more virulent than A. fumigatus in terms of inoculum required. Particularly common clinical syndromes associated with A. flavus include chronic granulomatous sinusitis, keratitis, cutaneous aspergillosis, wound infections and osteomyelitis following trauma and inoculation. Outbreaks associated with A. flavus appear to be associated with single or closely related strains, in contrast to those associated with A. fumigatus. In addition, A. flavus produces aflatoxins, the most toxic and potent hepatocarcinogenic natural compounds ever characterized. Accurate species identification within Aspergillus flavus complex remains difficult due to overlapping morphological and biochemical characteristics, and much taxonomic and population genetics work is necessary to better understand the species and related species. The flavus complex currently includes 23 species or varieties, including two sexual species, Petromyces alliaceus and P. albertensis. The genome of the highly related Aspergillus oryzae is completed and available; that of A. flavus in the final stages of annotation. Our understanding of A. flavus lags far behind that of A. fumigatus. Studies of the genomics, taxonomy, population genetics, pathogenicity, allergenicity and antifungal susceptibility of A. flavus are all required.
Seersholm, Frederik Valeur; Fischer, Anne; Heller, Martin
Mycoplasma capricolum subsp. capricolum is a well-known pathogen of small ruminants. A recent human case of septicemia involving this agent raised the question of its potential pathogenicity to humans. We present the first draft genome sequence of a human Mycoplasma capricolum subsp. capricolum...
Full Text Available North American crayfish species are natural hosts of the crayfish plague pathogen Aphanomyces astaci. The spiny-cheek crayfish Orconectes limosus, widespread in Central Europe, is the main reservoir of A. astaci in Czech Republic. We tested if there are temporal changes in the prevalence of infected individuals (i.e., the proportion of individuals in which the pathogen is detected in spiny-cheek crayfish populations. Crayfish from three populations shown previously to be infected to different extents (high, intermediate and low, were repeatedly sampled in different years (2004–2010 and seasons. The presence of A. astaci in the soft abdominal crayfish cuticle was tested by specific amplification of the pathogen DNA. There was no substantial temporal variation in pathogen prevalence in the highly and very lowly infected populations. However, a significant long-term as well as seasonal decrease was found in the intermediately infected population. This decline could be related to a decrease in population density over the studied years, and to crayfish seasonal moulting, respectively. A reliable estimate of pathogen prevalence in American crayfish populations thus requires repeated monitoring over years, preferably during the same season before the main period of crayfish moulting.
Kofoed, Kristian; Zalounina, Alina; Andersen, Ove
OBJECTIVES: To evaluate a decision support system (TREAT) for guidance of empirical antimicrobial therapy in an environment with a low prevalence of resistant pathogens. METHODS: A retrospective trial of TREAT has been performed at Copenhagen University, Hvidovre Hospital. The cohort of patients...
Vincy, M. V.; Brilliant, R.; Pradeepkumar, A. P.
The Meenachil, the only river that flows through the heart of the Kottayam district of Kerala state, India was selected for the study. The present study has been carried out with an objective to systematically examine the prevalence of indicator and pathogenic microorganisms and to compare the microbiological quality of the river water during the pre-monsoon and post-monsoon seasons. Water samples from 44 different sites during pre-monsoon and post-monsoon seasons were collected for the analysis. During the pre-monsoon period, the faecal coliform count ranged from 230 to 110,000 MPN/100 ml while there was a variation from 200 to 4600 MPN/100 ml during the post-monsoon period. When the faecal streptococci count was analysed, it ranged from 140 to 110,000 MPN/100 ml during the pre-monsoon and 70 to 4600 MPN/100 ml during the post-monsoon seasons, respectively. All the samples collected were found to have total viable count (TVC) higher than those prescribed by Bureau of Indian Standards (ISI 1991). Total viable counts were found in the range of 1.1 × 102 to 32 × 102 cfu/ml in the pre-monsoon and 1.0 × 102 to 26 × 102 cfu/ml in the post-monsoon. The presence of faecal indicator bacteria, Escherichia coli and potentially pathogenic bacteria, Vibrio cholerae, Vibrio parahaemolyticus and Salmonella enterica in the Meenachil River indicates that the bacteriological quality of the Meenachil River is poor. Moreover, it sheds light to the fact that raw sewage is being dumped into the Meenachil River. Urban runoffs and effluents of rubber factories appear to be the important sources of faecal contamination in the river. From this study, we conclude that these water bodies pose significant public health hazards. Adequate sanitary infrastructure will help in preventing source water contamination. Besides this, public health education aimed at improving personal, household and community hygiene is urgent.
Bollen, Ilse A E; Schuldt, Maike; Harakalova, Magdalena; Vink, Aryan; Asselbergs, Folkert W; Pinto, Jose R; Krüger, Martina; Kuster, Diederik W D; van der Velden, Jolanda
Mutations in genes encoding cardiac troponin I (TNNI3) and cardiac troponin T (TNNT2) caused altered troponin protein stoichiometry in patients with dilated cardiomyopathy. TNNI3 p.98trunc resulted in haploinsufficiency, increased Ca 2+ -sensitivity and reduced length-dependent activation. TNNT2 p.K217del caused increased passive tension. A mutation in the gene encoding Lamin A/C (LMNA p.R331Q ) led to reduced maximal force development through secondary disease remodelling in patients suffering from dilated cardiomyopathy. Our study shows that different gene mutations induce dilated cardiomyopathy via diverse cellular pathways. Dilated cardiomyopathy (DCM) can be caused by mutations in sarcomeric and non-sarcomeric genes. In this study we defined the pathogenic effects of three DCM-causing mutations: the sarcomeric mutations in genes encoding cardiac troponin I (TNNI3 p.98truncation ) and cardiac troponin T (TNNT2 p.K217deletion ; also known as the p.K210del) and the non-sarcomeric gene mutation encoding lamin A/C (LMNA p.R331Q ). We assessed sarcomeric protein expression and phosphorylation and contractile behaviour in single membrane-permeabilized cardiomyocytes in human left ventricular heart tissue. Exchange with recombinant troponin complex was used to establish the direct pathogenic effects of the mutations in TNNI3 and TNNT2. The TNNI3 p.98trunc and TNNT2 p.K217del mutation showed reduced expression of troponin I to 39% and 51%, troponin T to 64% and 53%, and troponin C to 73% and 97% of controls, respectively, and altered stoichiometry between the three cardiac troponin subunits. The TNNI3 p.98trunc showed pure haploinsufficiency, increased Ca 2+ -sensitivity and impaired length-dependent activation. The TNNT2 p.K217del mutation showed a significant increase in passive tension that was not due to changes in titin isoform composition or phosphorylation. Exchange with wild-type troponin complex corrected troponin protein levels to 83% of controls in the TNNI3
Schuldt, Maike; Harakalova, Magdalena; Vink, Aryan; Asselbergs, Folkert W.; Pinto, Jose R.; Krüger, Martina; Kuster, Diederik W. D.; van der Velden, Jolanda
Key points Mutations in genes encoding cardiac troponin I (TNNI3) and cardiac troponin T (TNNT2) caused altered troponin protein stoichiometry in patients with dilated cardiomyopathy. TNNI3p.98trunc resulted in haploinsufficiency, increased Ca2+‐sensitivity and reduced length‐dependent activation. TNNT2p.K217del caused increased passive tension.A mutation in the gene encoding Lamin A/C (LMNA p.R331Q) led to reduced maximal force development through secondary disease remodelling in patients suffering from dilated cardiomyopathy.Our study shows that different gene mutations induce dilated cardiomyopathy via diverse cellular pathways. Abstract Dilated cardiomyopathy (DCM) can be caused by mutations in sarcomeric and non‐sarcomeric genes. In this study we defined the pathogenic effects of three DCM‐causing mutations: the sarcomeric mutations in genes encoding cardiac troponin I (TNNI3p.98truncation) and cardiac troponin T (TNNT2p.K217deletion; also known as the p.K210del) and the non‐sarcomeric gene mutation encoding lamin A/C (LMNAp.R331Q). We assessed sarcomeric protein expression and phosphorylation and contractile behaviour in single membrane‐permeabilized cardiomyocytes in human left ventricular heart tissue. Exchange with recombinant troponin complex was used to establish the direct pathogenic effects of the mutations in TNNI3 and TNNT2. The TNNI3p.98trunc and TNNT2p.K217del mutation showed reduced expression of troponin I to 39% and 51%, troponin T to 64% and 53%, and troponin C to 73% and 97% of controls, respectively, and altered stoichiometry between the three cardiac troponin subunits. The TNNI3p.98trunc showed pure haploinsufficiency, increased Ca2+‐sensitivity and impaired length‐dependent activation. The TNNT2p.K217del mutation showed a significant increase in passive tension that was not due to changes in titin isoform composition or phosphorylation. Exchange with wild‐type troponin complex corrected troponin protein levels to 83% of
Brisebois, Evelyne; Veillette, Marc; Dion-Dupont, Vanessa; Lavoie, Jacques; Corbeil, Jacques; Culley, Alexander; Duchaine, Caroline
Wastewater treatment center (WTC) workers may be vulnerable to diseases caused by viruses, such as the common cold, influenza and gastro-intestinal infections. Although there is a substantial body of literature characterizing the microbial community found in wastewater, only a few studies have characterized the viral component of WTC aerosols, despite the fact that most diseases affecting WTC workers are of viral origin and that some of these viruses are transmitted through the air. In this study, we evaluated in four WTCs the presence of 11 viral pathogens of particular concern in this milieu and used a metagenomic approach to characterize the total viral community in the air of one of those WTCs. The presence of viruses in aerosols in different locations of individual WTCs was evaluated and the results obtained with four commonly used air samplers were compared. We detected four of the eleven viruses tested, including human adenovirus (hAdV), rotavirus, hepatitis A virus (HAV) and Herpes Simplex virus type 1 (HSV1). The results of the metagenomic assay uncovered very few viral RNA sequences in WTC aerosols, however sequences from human DNA viruses were in much greater relative abundance. Copyright © 2017. Published by Elsevier B.V.
Prevalence and characteristics of articular manifestations in human immune virus infection. ... Objectives: To determine the prevalence, types and characteristics of articular manifestations in the anti-retroviral treatment naive HIV infected patients. Design: Cross sectional descriptive study. Setting: Comprehensive care clinic ...
Three hundred and seven (307) healthy blood donors aged 18 – 55 years were used to determine the sero-prevalence of Human Immunodeficiency Virus (HIV) and Hepatitis B virus (HBV) in Yola, Nigeria. The association between donors' age, occupation and marital status and the prevalence of the infections among blood ...
Lipp, E K; Farrah, S A; Rose, J B
The goals of this study were to assess watersheds impacted by high densities of OSDS (onsite sewage disposal systems) for evidence of fecal contamination and evaluate the occurrence of human pathogens in coastal waters off west Florida. Eleven stations (representing six watersheds) were intensively sampled for microbial indicators of fecal pollution (fecal coliform bacteria, enterococci, Clostridium perfringens and coliphage) and the human enteric pathogens, Cryptosporidium, Giardia, and enteroviruses during the summer rainy season (May-September 1996). Levels of all indicators ranged between 4000 CFU/100 ml. Cryptosporidium and Giardia were detected infrequently (6.8% and 2.3% of samples tested positive, respectively). Conversely, infectious enteroviruses were detected at low levels in 5 of the 6 watersheds sampled. Using cluster analysis, sites were grouped into two categories, high and low risks, based on combined levels of indicators. These results suggest that stations of highest pollution risk were located within areas of high OSDS densities. Furthermore, data indicate a subsurface transport of contaminated water to surface waters. The high prevalence of enteroviruses throughout the study area suggests a chronic pollution problem and potential risk to recreational swimmers in and around Sarasota Bay.
Varela, José A; Otero, Luis; García, María José; Palacio, Virgilo; Carreño, Francisco; Cuesta, Mar; Sánchez, Carmen; Vázquez, Fernando
There are few studies of recent trends in the etiology and epidemiologic characteristics of specific microorganisms causing urethritis in men. The objective of the current study was to show the clinical experience in our country and to evaluate the trends in the prevalence of the pathogens in male urethritis, as well as the epidemiologic patterns in a series of 2101 patients. This was a descriptive study of the etiological agents causing urethritis in our sexually transmitted disease clinics in a period of 12 years (1989-2000), with a comparison of two periods of time. There were 97 cases of gonococcal urethritis (4.6%), 2004 of nongonococcal urethritis (95.4%), and 82 of mixed urethritis (3.9%). An association was found between gonococcal urethritis and heterosexual men; between chlamydial urethritis and homosexual/bisexual men; Ureaplasma urealyticum urethritis and heterosexual men and patients younger than 30 years of age; and between trichomonal urethritis and patients more than 30 years of age and the presence of HIV antibodies. During the period of research there was a significant decrease in cases of Neisseria gonorrhoeae and Chlamydia trachomatis urethritis and an increase in those of U urealyticum urethritis. In conclusion, this report describes changes in the etiology and epidemiologic patterns of urethritis in our country in recent years.
Matthew D Dyer
Full Text Available Bacillus anthracis, Francisella tularensis, and Yersinia pestis are bacterial pathogens that can cause anthrax, lethal acute pneumonic disease, and bubonic plague, respectively, and are listed as NIAID Category A priority pathogens for possible use as biological weapons. However, the interactions between human proteins and proteins in these bacteria remain poorly characterized leading to an incomplete understanding of their pathogenesis and mechanisms of immune evasion.In this study, we used a high-throughput yeast two-hybrid assay to identify physical interactions between human proteins and proteins from each of these three pathogens. From more than 250,000 screens performed, we identified 3,073 human-B. anthracis, 1,383 human-F. tularensis, and 4,059 human-Y. pestis protein-protein interactions including interactions involving 304 B. anthracis, 52 F. tularensis, and 330 Y. pestis proteins that are uncharacterized. Computational analysis revealed that pathogen proteins preferentially interact with human proteins that are hubs and bottlenecks in the human PPI network. In addition, we computed modules of human-pathogen PPIs that are conserved amongst the three networks. Functionally, such conserved modules reveal commonalities between how the different pathogens interact with crucial host pathways involved in inflammation and immunity.These data constitute the first extensive protein interaction networks constructed for bacterial pathogens and their human hosts. This study provides novel insights into host-pathogen interactions.
Full Text Available Pediculus humanus humanus is an human ectoparasite which represents a serious public health threat because it is vector for pathogenic bacteria. It is important to understand and identify where bacteria reside in human body lice to define new strategies to counterstroke the capacity of vectorization of the bacterial pathogens by body lice. It is known that phagocytes from vertebrates can be hosts or reservoirs for several microbes. Therefore, we wondered if Pediculus humanus humanus phagocytes could hide pathogens. In this study, we characterized the phagocytes from Pediculus humanus humanus and evaluated their contribution as hosts for human pathogens such as Rickettsia prowazekii, Bartonella quintana and Acinetobacter baumannii.
Osman, Kamelia M; Zolnikov, Tara Rava; Samir, Ahmed; Orabi, Ahmed
Goat and sheep milk is consumed by human populations throughout the world; as a result, it has been proposed as an alternative, nutrient-rich milk to feed infants allergic to cow's milk. Unfortunately, potentially harmful bacteria have not been thoroughly tested in goat or sheep milk. Listeria monocytogenes is a harmful bacterium that causes adverse health effects if ingested by humans. The purpose of this study was to estimate the prevalence and characterize the phenotype, genotype, virulence factors, biofilm formation, and antibiopotential of Listeria isolated from the milk of goat and sheep. Udder milk samples were collected from 107 goats and 102 sheep and screened for mastitis using the California mastitis test (CMT). Samples were then examined for the presence of pathogenic Listeria spp; if detected, the isolation of pathogenic Listeria (L. monocytogenes and Listeria ivanovii) was completed using isolation and identification techniques recommended by the International Organization for Standards (ISO 11290-1, 1996), in addition to serological, in vitro and in vivo pathogenicity tests. The isolates were subjected to PCR assay for virulence associated genes (hlyA, plcA, actA, and iap). Pathogenic Listeria spp. were isolated from 5·6% of goat and 3·9% sheep milk samples, with 33·3 and 25% of these selected samples respectively containing L. monocytogenes. The results of this study provide evidence of the low-likelihood of contamination leading to the presence of L. monocytogenes in raw goat and sheep milk; however, this study also confirmed a strong in vitro ability for biofilm formation and pathogenic capability of L. monocytogenes if discovered in the milk. L. monocytogenes may be present in goat and sheep milk and in order to reduce the exposure, hygienic milking conditions must be employed for the milk to be considered a safe alternative for human consumption.
Benschop, K.; Thomas, X.; Serpenti, C.; Molenkamp, R.; Wolthers, K.
Human Parechoviruses (HPeV) are widespread pathogens belonging to the Picornavirus family. Six genotypes are known which have predominantly been isolated from children. Data on prevalence of HPeV genotypes are generally based on cell culture, which may underestimate the prevalence of certain HPeV
Gungor, A; Cincik, H; Baloglu, H; Cekin, E; Dogru, S; Dursun, E
To determine the prevalence and type of human papilloma virus deoxyribonucleic acid (DNA) in cases of laryngeal squamous cell carcinoma. We analysed the prevalence of human papilloma virus infection in archived paraffin block specimens taken from 99 cases of laryngeal squamous cell carcinoma between 1990 and 2005, using polymerase chain reaction techniques. Biopsy specimens from five proven verrucous skin lesions were used as positive controls, and peripheral blood samples from five healthy volunteers were used as negative controls. Four test samples were found to have inadequate deoxyribonucleic acid purity and were therefore excluded from the study. Human papilloma virus deoxyribonucleic acid was detected in seven of 95 cases of laryngeal squamous cell carcinoma (7.36 per cent). Human papilloma virus genotyping revealed double human papilloma virus infection in three cases and single human papilloma virus infection in the remaining four cases. The human papilloma virus genotypes detected were 6, 11 and 16 (the latter detected in only one case). In our series, a very low human papilloma virus prevalence was found among laryngeal squamous cell carcinoma cases. The human papilloma virus genotypes detected were mostly 6 and/or 11, and 16 in only one case. To the best of our knowledge, this is the first report of human papilloma virus prevalence in laryngeal squamous cell carcinoma, based on polymerase chain reaction genotyping in a Turkish population.
Lewis, David A; Chirwa, Tobias F; Msimang, Veerle M Y; Radebe, Frans M; Kamb, Mary L; Firnhaber, Cynthia S
To determine sexually transmitted infection (STI) prevalence, and patient characteristics associated with detection of urethritis/cervicitis pathogens, among HIV-infected individuals offered voluntary STI screening at a South African HIV treatment center. Individuals, asymptomatic for genital discharge, were screened for Neisseria gonorrhoeae (NG), Chlamydia trachomatis, Trichomonas vaginalis (TV), Mycoplasma genitalium (MG) infections (real-time polymerase chain reaction assay), for syphilis and herpes simplex type 2 (serologically), and for bacterial vaginosis and Candida (microscopy, women only). Patients' most recent CD4 and viral load results were recorded. Demographic, clinical, and behavioral data were collected by nurse-administered questionnaire. Compared with men (n = 551), women (n = 558) were younger (mean age, 35.0 vs. 37.9 years; P urethritis/cervicitis pathogens detected (21.3% vs.16.4%, P = 0.035), and were less aware of their partner's HIV status (53.1% vs. 62.3%; P = 0.007). The overall prevalence of individual urethritis/cervicitis pathogens was TV (7.6%), MG (6.1%), NG (5.4%), and C. trachomatis (2.1%). Multivariate analysis highlighted 4 significant factors associated with the detection of specific urethritis/cervicitis pathogens, namely female gender (TV, adjusted odds ratio [aOR] 2.53, 95% confidence interval [CI]: 1.47-4.37), having a regular sexual partner in the past 3 months (NG, aOR 2.26, 95% CI: 1.01-5.08), suboptimal condom use with regular partners (TV, aOR 2.07, 95% CI: 1.25-3.42), and a history of genital warts in the past year (NG, 2.25, 95% CI: 1.26-4.03). Asymptomatic urethritis/cervicitis pathogens were highly prevalent in this population. Few urethritis/cervicitis pathogen-associated patient characteristics were identified, emphasizing the need for affordable STI diagnostics to screen HIV-infected patients.
Forsberg, Kevin J.; Reyes, Alejandro; Wang, Bin
protocol to assemble short-read sequence data after antibiotic selection experiments, using 12 different drugs in all antibiotic classes, and compared antibiotic resistance gene sequences between soil bacteria and clinically occurring pathogens. Sixteen sequences, representing seven gene products, were...... discovered in farmland soil bacteria within long stretches of perfect nucleotide identity with pathogenic proteobacteria....
harm to some extent by the association or may cause death. Human ... Center and Specialist Hospital Yola, Adamawa state. MATERIALS ..... of animal dungs as manure could aid in transfer of cysts. .... American Journal of Tropical. Medicine ...
Full Text Available Detection and genotyping of pathogenic RNA viruses in human and environmental samples are useful for monitoring the circulation and prevalence of these pathogens, whereas a conventional PCR assay followed by Sanger sequencing is time-consuming and laborious. The present study aimed to develop a high-throughput detection-and-genotyping tool for 11 human RNA viruses [Aichi virus; astrovirus; enterovirus; norovirus genogroup I (GI, GII, and GIV; hepatitis A virus; hepatitis E virus; rotavirus; sapovirus; and human parechovirus] using a microfluidic device and next-generation sequencer. Microfluidic nested PCR was carried out on a 48.48 Access Array chip, and the amplicons were recovered and used for MiSeq sequencing (Illumina, Tokyo, Japan; genotyping was conducted by homology searching and phylogenetic analysis of the obtained sequence reads. The detection limit of the 11 tested viruses ranged from 100 to 103 copies/μL in cDNA sample, corresponding to 101–104 copies/mL-sewage, 105–108 copies/g-human feces, and 102–105 copies/g-digestive tissues of oyster. The developed assay was successfully applied for simultaneous detection and genotyping of RNA viruses to samples of human feces, sewage, and artificially contaminated oysters. Microfluidic nested PCR followed by MiSeq sequencing enables efficient tracking of the fate of multiple RNA viruses in various environments, which is essential for a better understanding of the circulation of human pathogenic RNA viruses in the human population.
Background: Malaria has been and is still a major protozoan disease affecting the human population. Erythrocyte polymorphisms (mainly in blood groups and genotypes) influence the susceptibility to severe malaria. Aim: This study is aimed at assessing the prevalence malaria in relation to human blood factor and to ...
Full Text Available Bacterial pathogens and human norovirus (HuNoV are major cause for acute gastroenteritis caused by contaminated food and water. Public waterways can become contaminated from a variety of sources and flood after heavy rain events, leading to pathogen contamination of produce fields. We initiated a survey of several public watersheds in a major leafy green produce production region of the Central California Coast to determine the prevalence of HuNoV as well as bacterial pathogens. Moore swabs were used to collect environmental samples bi-monthly at over 30 sampling sites in the region. High prevalence of HuNoV and bacterial pathogens were detected in environmental water samples in the region. The overall detection rates of HuNoV, O157 Shiga toxin-producing Escherichia coli (STEC, non-O157 STEC, Salmonella, and Listeria were 25.58, 7.91, 9.42, 59.65, and 44.30%, respectively. The detection rates of Salmonella and L. monocytogenes were significantly higher in the spring. Fall and spring had elevated detection rates of O157 STEC. The overall detection rates of non-O157 STEC in the fall were lower than the other seasons but not significant. The overall detection rates of HuNoV were highest in fall, followed by spring and winter, with summer being lowest and significantly lower than other seasons. This study presented the first study of evaluating the correlation between the detection rate of HuNoV and the detection rates of four bacterial pathogens from environmental water. Overall, there was no significant difference in HuNoV detection rates between samples testing positive or negative for the four bacterial pathogens tested. Pathogens in animal-impacted and human-impacted areas were investigated. There were significant higher detection rates in animal-impacted areas than that of human-impacted areas for bacterial pathogens. However, there was no difference in HuNoV detection rates between these two areas. The overall detection levels of generic E
Varanat, M; Haase, E M; Kay, J G; Scannapieco, F A
Periodontitis is a highly prevalent disease caused in part by an aberrant host response to the oral multi-species biofilm. A balance between the oral bacteria and host immunity is essential for oral health. Imbalances in the oral microbiome lead to an uncontrolled host inflammatory response and subsequent periodontal disease (i.e. gingivitis and periodontitis). TREM-1 is a signaling receptor present on myeloid cells capable of acting synergistically with other pattern recognition receptors leading to amplification of inflammatory responses. The aim of this study was to investigate the activation of the TREM-1 pathway in the human monocyte-like cell line THP-1 exposed to both oral pathogens and commensals. The relative expression of the genes encoding TREM-1 and its adapter protein DAP12 were determined by quantitative real-time polymerase chain reaction. The surface expression of TREM-1 was determined by flow cytometry. Soluble TREM-1 and cytokines were measured by enzyme-linked immunosorbent assay. The results demonstrate that both commensal and pathogenic oral bacteria activate the TREM-1 pathway, resulting in a proinflammatory TREM-1 activity-dependent increase in proinflammatory cytokine production. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Li, Lijie; Qin, Tian; Li, Yun; Zhou, Haijian; Song, Hongmei; Ren, Hongyu; Li, Liping; Li, Yongguang; Zhao, Dong
Cooling towers are a source of Legionnaires' disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU)/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%), 6 (25, 20.7%), 5 (12, 9.9%), 8 (8, 6.6%), 3 (6, 5.0%) and 9 (2, 1.6%). All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE) and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT), a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR). 92.6% (112/121) and 98.3% (119/121) isolates carried lvh and rtxA respectively and 90.9% (110/121) of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed.
Full Text Available Cooling towers are a source of Legionnaires’ disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%, 6 (25, 20.7%, 5 (12, 9.9%, 8 (8, 6.6%, 3 (6, 5.0% and 9 (2, 1.6%. All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT, a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR. 92.6% (112/121 and 98.3% (119/121 isolates carried lvh and rtxA respectively and 90.9% (110/121 of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed.
Olesen, Tina Bech; Svahn, Malene Frøsig; Faber, Mette Tuxen
HPV is a common sexually transmitted infection and is considered to be a necessary cause of cervical cancer. The anatomical proximity to the cervix has led researchers to investigate whether Human Papillomavirus (HPV) has a role in the etiology of endometrial cancer.......HPV is a common sexually transmitted infection and is considered to be a necessary cause of cervical cancer. The anatomical proximity to the cervix has led researchers to investigate whether Human Papillomavirus (HPV) has a role in the etiology of endometrial cancer....
Cashdan, Elizabeth; Steele, Matthew
It has been argued that people in areas with high pathogen loads will be more likely to avoid outsiders, to be biased in favor of in-groups, and to hold collectivist and conformist values. Cross-national studies have supported these predictions. In this paper we provide new pathogen codes for the 186 cultures of the Standard Cross-Cultural Sample and use them, together with existing pathogen and ethnographic data, to try to replicate these cross-national findings. In support of the theory, we found that cultures in high pathogen areas were more likely to socialize children toward collectivist values (obedience rather than self-reliance). There was some evidence that pathogens were associated with reduced adult dispersal. However, we found no evidence of an association between pathogens and our measures of group bias (in-group loyalty and xenophobia) or intergroup contact.
Full Text Available In this study, attempts were made to isolate Streptomyces sp. from soil samples of two different regions of Bangladesh and evaluate their antagonistic activity against fish and human pathogenic bacteria. A total of 10 isolates were identified as Streptomyces sp. based on several morphological, physiological and biochemical tests. Cross streak method was used to observe the antagonistic activity of the Streptomyces sp. isolates against different fish pathogens belonging to the genus Aeromonas, Pseudomonas and Edwardsiella and human clinical isolates belonging to the genus Klebsiella, Salmonella and Streptococcus. Seven Streptomyces sp. isolates showed antagonism against both fish and human pathogenic bacteria. Four isolates viz., N24, N26, N28 and N47 showed broad spectrum of antagonistic activity (80-100% against all genera of fish and human pathogenic bacteria. The isolate N49 exhibited highest spectrum of antagonism against all fish pathogens (90-100% but comparatively lower degree of antagonism against human pathogens (50-60%. Rest of the two isolates (N21 and N23 showed variability in their antagonism. Results showed that broad spectrum antibiotic(s could be developed from the isolates N24, N26, N28 and N47against several human and fish pathogens. The isolate N49 could be a potential source of antibiotic, especially for fish pathogenic bacteria.
Tenhagen, Bernd-Alois; Hansen, Inken; Reinecke, Annette; Heuwieser, Wolfgang
Prevalence of mastitis pathogens in milk samples from dairy cows and heifers was studied over a period of 1 year (Aug 2005-Aug 2006) in ten dairy herds in Germany. Milk samples (n=8240) were collected from heifers without clinical mastitis at parturition (n=6915), from primiparous cows with clinical mastitis (n=751) and from older cows with clinical mastitis (n=574). Coagulase negative staphylococci (CNS) were the predominant group of bacteria isolated (46.8% of samples) from clinically healthy quarters of primiparous cows around parturition, followed by streptococci (12.6%), coliforms (4.7%) and Staphylococcus aureus (4.0%). Thirty-three percent of samples were negative on culture (range on farm level, 12.0-46.4%). In cases of clinical mastitis in primiparous and older cows, streptococci were the predominant finding (32.1 and 39.2%) followed by CNS (27.4 and 16.4%), coliforms (10.3 and 13.1%) and Staph. aureus (10.0 and 11.7%). Negative results were obtained from 21.3% (range, 0.0-30.6%) and 19.5% (range, 0.0-32.6%) of these samples. Results indicated substantial differences in the prevalence of pathogens among herds. There was a positive within-herd correlation between the monthly prevalences for Streptococcus dysgalactiae between the three groups of samples. This correlation was also found between clinical samples of primiparous and older cows for Staph. aureus. These correlations were not found for the other pathogens. Besides herd, prevalence of pathogens was influenced by parity, type of sample and season.
McManus Donald P
Full Text Available Abstract Background The schistosome blood flukes are complex trematodes and cause a chronic parasitic disease of significant public health importance worldwide, schistosomiasis. Their life cycle is characterised by distinct parasitic and free-living phases involving mammalian and snail hosts and freshwater. Microarray analysis was used to profile developmental gene expression in the Asian species, Schistosoma japonicum. Total RNAs were isolated from the three distinct environmental phases of the lifecycle – aquatic/snail (eggs, miracidia, sporocysts, cercariae, juvenile (lung schistosomula and paired but pre-egg laying adults and adult (paired, mature males and egg-producing females, both examined separately. Advanced analyses including ANOVA, principal component analysis, and hierarchal clustering provided a global synopsis of gene expression relationships among the different developmental stages of the schistosome parasite. Results Gene expression profiles were linked to the major environmental settings through which the developmental stages of the fluke have to adapt during the course of its life cycle. Gene ontologies of the differentially expressed genes revealed a wide range of functions and processes. In addition, stage-specific, differentially expressed genes were identified that were involved in numerous biological pathways and functions including calcium signalling, sphingolipid metabolism and parasite defence. Conclusion The findings provide a comprehensive database of gene expression in an important human pathogen, including transcriptional changes in genes involved in evasion of the host immune response, nutrient acquisition, energy production, calcium signalling, sphingolipid metabolism, egg production and tegumental function during development. This resource should help facilitate the identification and prioritization of new anti-schistosome drug and vaccine targets for the control of schistosomiasis.
Wetmore, Catherine M; Manhart, Lisa E; Golden, Matthew R
Urethritis is the most common male reproductive tract disease syndrome; yet 20-50% of diagnosed cases have no defined etiology, and few population-level data exist on the prevalence or etiology of the syndrome. We estimated the prevalence of urethritis among young men in the United States and compared correlates of idiopathic cases to correlates of detected infections with sexually transmitted pathogens. Questionnaire data and urine specimens from 5,447 men aged 18-27 years participating in Wave III of the National Longitudinal Study of Adolescent Health were analyzed. Symptomatic urethritis was defined as self-reported dysuria or urethral discharge in the past 24hours. Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, and Mycoplasma genitalium were identified using nucleic acid amplification tests. Idiopathic urethritis (IU) was defined as urethral symptoms in the absence of these four pathogens. Stratified weighted analyses generated population-based estimates. Urethritis was reported by 1.2% (95% CI=.8-1.6%) of men, of whom 82.4% (61.1-93.3%) had IU. Men with previous STD diagnoses (aOR=9.3 [95% CI=3.0-28.7]), or fewer (1-4) or no lifetime vaginal sex partners (aOR=7.5 [2.9-19.3] and aOR=7.2 [1.9-27.4]), were more likely to have IU compared with men without urethral symptoms or identified pathogens, whereas men of Native American or Asian/Pacific Islander descent (aOR=.04 [.01-.2]) and heavy drinkers (aOR=.08 [.03-.2]) were less likely to have IU. Unlike infection with known pathogens, IU was not associated with black race, Hispanic ethnicity, or age at sexual debut. Urethral symptoms were rarely associated with known pathogens. IU and known pathogens were associated with distinct characteristics.
Díaz-López, A; Cantú-Ramírez, R C; Garza-González, E; Ruiz-Tolentino, L; Tellez-Luis, S J; Rivera, G; Bocanegra-García, V
We analyzed a total of 70 grilled chicken samples bought randomly from street vendors and retail outlets in the city of Reynosa, Mexico, to determine the prevalence of Escherichia coli (Shiga toxin producing and enterotoxin producing), Salmonella spp., Staphylococcus aureus, Listeria spp., and Campylobacter spp. using microbiological methods and PCR detection of bacterial sequences. Of the 70 samples, 27 (38.5%) were from retail outlets and 43 (61.4%) from street vendors. All specimens were negative by both microbiological and molecular methods for Listeria monocytogenes, Shiga toxin 2 of Shiga toxin-producing E. coli, lt of enterotoxin-producing E. coli, and st enterotoxin, and all were negative for Salmonella spp. and Campylobacter jejuni by PCR. Of the samples studied, 49 (70%) had undetectable levels of the foodborne pathogens studied with the methods used. In the remaining 21 (30%) specimens, at least one pathogen was isolated or detected, with E. coli being the pathogen most frequently isolated and with two samples bearing the hlyA gene. We found no statistical difference in bacterial prevalence between retail and street vendor samples. The presence of pathogens in grilled chicken is an important public health risk because of the great demand for and daily consumption of this product in this region.
Aktaş, Osman; Aydin, Hakan; Uslu, Hakan
Human parvovirus B19 is a pathogen that affects different parts of the body. We planned this study because of the lack of data on B19 seroprevalence based on different body-system diseases. The prevalence of parvovirus B19 antibodies was investigated retrospectively in 1239 patients by review of medical records from 2009-2012, according to their diseases classified under general titles in compliance with the International Classification of Diseases (ICD-10). Parvovirus B19-specific antibodies were detected by quantitative enzyme immunoassays. The positivity rate was 27.8% for only IgG, 8.5% for only IgM, and 2.6% for both IgG and IgM. The highest positivity for IgG alone was found in musculoskeletal system and connective tissue diseases (55.9%), while the highest positivity for IgM was found in neoplasms (16.4%). The highest positivity for IgG was seen in rheumatoid arthritis (72.2%) and pregnancy (52.6%), and the highest positivity for total IgM was found in upper respiratory tract disease (21.0%) and hepatic failure (17.1%). Parvovirus B19 seroprevalence was relatively low in northeastern Anatolia compared to most serological studies conducted in other regions. We think that this study has provided the first wide-ranging information on the seroprevalence of B19 in diseases and disorders of the major human body systems.
Martins Natalia F
Full Text Available Abstract Background The prevalence of invasive fungal infections (IFIs has increased steadily worldwide in the last few decades. Particularly, there has been a global rise in the number of infections among immunosuppressed people. These patients present severe clinical forms of the infections, which are commonly fatal, and they are more susceptible to opportunistic fungal infections than non-immunocompromised people. IFIs have historically been associated with high morbidity and mortality, partly because of the limitations of available antifungal therapies, including side effects, toxicities, drug interactions and antifungal resistance. Thus, the search for alternative therapies and/or the development of more specific drugs is a challenge that needs to be met. Genomics has created new ways of examining genes, which open new strategies for drug development and control of human diseases. Results In silico analyses and manual mining selected initially 57 potential drug targets, based on 55 genes experimentally confirmed as essential for Candida albicans or Aspergillus fumigatus and other 2 genes (kre2 and erg6 relevant for fungal survival within the host. Orthologs for those 57 potential targets were also identified in eight human fungal pathogens (C. albicans, A. fumigatus, Blastomyces dermatitidis, Paracoccidioides brasiliensis, Paracoccidioides lutzii, Coccidioides immitis, Cryptococcus neoformans and Histoplasma capsulatum. Of those, 10 genes were present in all pathogenic fungi analyzed and absent in the human genome. We focused on four candidates: trr1 that encodes for thioredoxin reductase, rim8 that encodes for a protein involved in the proteolytic activation of a transcriptional factor in response to alkaline pH, kre2 that encodes for α-1,2-mannosyltransferase and erg6 that encodes for Δ(24-sterol C-methyltransferase. Conclusions Our data show that the comparative genomics analysis of eight fungal pathogens enabled the identification of
Parvoviruses are minute single-stranded DNA viruses that infect a wide range of mammalians and invertebrates. Human parvovirus B19 (B19V) was discovered in the 1970s and was soon found to cause several diseases, including erythema infectiosum, arthropathy, anemias, fetal hydrops, and fetal death. The B19V titer in blood is high during acute infection. After primary infection, B19V has been shown to persist in tissues of symptomatic and asymptomatic persons. Prior to the commencement of this w...
Iraola, Gregorio; Vazquez, Gustavo; Spangenberg, Lucía; Naya, Hugo
Although there have been great advances in understanding bacterial pathogenesis, there is still a lack of integrative information about what makes a bacterium a human pathogen. The advent of high-throughput sequencing technologies has dramatically increased the amount of completed bacterial genomes, for both known human pathogenic and non-pathogenic strains; this information is now available to investigate genetic features that determine pathogenic phenotypes in bacteria. In this work we determined presence/absence patterns of different virulence-related genes among more than finished bacterial genomes from both human pathogenic and non-pathogenic strains, belonging to different taxonomic groups (i.e: Actinobacteria, Gammaproteobacteria, Firmicutes, etc.). An accuracy of 95% using a cross-fold validation scheme with in-fold feature selection is obtained when classifying human pathogens and non-pathogens. A reduced subset of highly informative genes () is presented and applied to an external validation set. The statistical model was implemented in the BacFier v1.0 software (freely available at ), that displays not only the prediction (pathogen/non-pathogen) and an associated probability for pathogenicity, but also the presence/absence vector for the analyzed genes, so it is possible to decipher the subset of virulence genes responsible for the classification on the analyzed genome. Furthermore, we discuss the biological relevance for bacterial pathogenesis of the core set of genes, corresponding to eight functional categories, all with evident and documented association with the phenotypes of interest. Also, we analyze which functional categories of virulence genes were more distinctive for pathogenicity in each taxonomic group, which seems to be a completely new kind of information and could lead to important evolutionary conclusions. PMID:22916122
Leo eVan Overbeek
Full Text Available Disease incidences related to Escherichia coli and Salmonella enterica infections by consumption of (fresh vegetables, sprouts and occasionally fruits made clear that these pathogens are not only transmitted to humans via the ‘classical’ routes of meat, eggs and dairy products, but also can be transmitted to humans via plants or products derived from plants. Nowadays, it is of major concern that these human pathogens, especially the ones belonging to the taxonomical family of Enterobacteriaceae, become adapted to environmental habitats without losing their virulence to humans. Adaptation to the plant environment would lead to longer persistence in plants, increasing their chances on transmission to humans via consumption of plant-derived food. One of the mechanisms of adaptation to the plant environment in human pathogens, proposed in this paper, is horizontal transfer of genes from different microbial communities present in the arable ecosystem, like the ones originating from soil, animal digestive track systems (manure, water and plants themselves. Genes that would confer better adaptation to the phytosphere might be genes involved in plant colonization, stress resistance and nutrient acquisition and utilization. Because human pathogenic enterics often were prone to genetic exchanges via phages and conjugative plasmids, it was postulated that these genetic elements may be hold key responsible for horizontal gene transfers between human pathogens and indigenous microbes in agroproduction systems. In analogy to zoonosis, we coin the term phytonosis for a human pathogen that is transmitted via plants and not exclusively via animals.
Hodgkinson, Alison J; Cakebread, Julie; Callaghan, Megan; Harris, Paul; Brunt, Rachel; Anderson, Rachel C; Armstrong, Kelly M; Haigh, Brendan
Secretory IgA (SIgA) from milk contributes to early colonization and maintenance of commensal/symbiotic bacteria in the gut, as well as providing defence against pathogens. SIgA binds bacteria using specific antigenic sites or non-specifically via its glycans attached to α-heavy-chain and secretory component. In our study, we tested the hypothesis that human and bovine SIgA have similar innate-binding activity for bacteria. SIgAs, isolated from human and bovine milk, were incubated with a selection of commensal, pathogenic and probiotic bacteria. Using flow cytometry, we measured numbers of bacteria binding SIgA and their level of SIgA binding. The percentage of bacteria bound by human and bovine SIgA varied from 30 to 90% depending on bacterial species and strains, but was remarkably consistent between human and bovine SIgA. The level of SIgA binding per bacterial cell was lower for those bacteria that had a higher percentage of SIgA-bound bacteria, and higher for those bacteria that had lower percentage of SIgA-bound bacteria. Overall, human and bovine SIgA interacted with bacteria in a comparable way. This contributes to longer term research about the potential benefits of bovine SIgA for human consumers. Copyright © 2016 Elsevier Ltd. All rights reserved.
Contamination of foods with human pathogens such as Salmonella, Listeria monocytogenes, Escherichia coli O157:H7, norovirus, and other pathogens is an ongoing challenge for growers and processors. In recent years, cold plasma has emerged as a promising antimicrobial treatment for fresh and fresh-cut...
Full Text Available Telomerase activity has been measured in a wide variety of cancerous and non-cancerous tissue types, and the vast majority of clinical studies have shown a direct correlation between it and the presence of cancerous cells. Telomerase plays a key role in cellular immortality and tumorigenesis. Telomerase is activated in 80–90% of human carcinomas, but not in normal somatic cells, therefore, its detection holds promise as a diagnostic marker for cancer. Measurable levels of telomerase have been detected in malignant cells from various samples: tissue from gestational trophoblastic neoplasms; squamous carcinoma cells from oral rinses; lung carcinoma cells from bronchial washings; colorectal carcinoma cells from colonic luminal washings; bladder carcinoma cells from urine or bladder washings; and breast carcinoma or thyroid cancer cells from fine needle aspirations. Such clinical tests for telomerase can be useful as non-invasive and cost-effective methods for early detection and monitoring of cancer. In addition, telomerase activity has been shown to correlate with poor clinical outcome in late-stage diseases such as non-small cell lung cancer, colorectal cancer, and soft tissue sarcomas. In such cases, testing for telomerase activity can be used to identify patients with a poor prognosis and to select those who might benefit from adjuvant treatment. Our review of the latest medical advances in this field reveals that telomerase holds great promise as a biomarker for early cancer detection and monitoring, and has considerable potential as the basis for developing new anticancer therapies.
Janse, Jacqueline J.; Wong, Gary W. K.; Potts, James; Ogorodova, Ludmila M.; Fedorova, Olga S.; Mahesh, P. A.; Sakellariou, Alexandros; Papadopoulos, Nikolaos G.; Knulst, André C.; Versteeg, Serge A.; Kroes, Aloys C. M.; Vossen, Ann C. T. M.; Campos Ponce, Maiza; Kummeling, Ischa; Burney, Peter; van Ree, Ronald; Yazdanbakhsh, Maria
An inverse association between markers of exposure to foodborne and orofecal pathogens and allergic sensitization has been reported. However, the findings of epidemiological studies have not been consistent. This study investigated the relationship between antibodies to hepatitis A, Toxoplasma
Janse, J.J.; Wong, G.W.K.; Potts, J.; Ogorodova, L.M.; Fedorova, O.S.; Mahesh, P.A.; Sakellariou, A.; Papadopoulos, N.G.; Knulst, A.C.; Versteeg, S.A.; Kroes, A.C.M.; Vossen, A.C.T.M.; Campos Ponce, M.; Kummeling, I.; Burney, P.; van Ree, R.; Yazdanbakhsh, M.
Background: An inverse association between markers of exposure to foodborne and orofecal pathogens and allergic sensitization has been reported. However, the findings of epidemiological studies have not been consistent. This study investigated the relationship between antibodies to hepatitis A,
Stocks from pathogenic fungi isolated from infected areas on different patients, around Lagos-Nigeria were analysed using molecular methods (DNA extraction, PCR-RFLP and DNA sequencing). Four DNA extraction protocols were employed in the identification of the fungal isolates. Sixteen different fungal isolates were ...
With an increasing number of outbreaks and illnesses associated with pre-harvest contaminated produce, understanding the potential and mechanisms of produce contamination by enteric pathogens can aid in the development of preventative measures and post-harvest processing to reduce microbial populati...
Simonsen, Karina T.; Nielsen, Jesper S.; Hansen, Annie A.
In nature, C. elegans lives in the soil and feeds on bacteria. This constant contact with soil-borne microbes suggests that nematodes must have evolved protective responses against pathogens which makes the worm an attractive host-pathogen model for exploring their innate immune response....... In addition, C. elegans is a promising model for the identification of novel virulence factors in various pathogens. A large number of human, animal, plant and insect pathogens have been shown to kill the worm, when C. elegans was allowed to feed on pathogens in stead of its normal laboratory diet [1......]. However, the mechanisms that lead to the shortened life span of the worm have been shown to be very different depending on the nature of the pathogen. Examples include Yersinia pestis, which forms a biofilm layer on the cuticle of C. elegans thus inhibiting feeding , enteropathogenic Escherichia coli...
Ghamrawi, Sarah; Rénier, Gilles; Saulnier, Patrick; Cuenot, Stéphane; Zykwinska, Agata; Dutilh, Bas E; Thornton, Christopher; Faure, Sébastien; Bouchara, Jean-Philippe
Progress in extending the life expectancy of cystic fibrosis (CF) patients remains jeopardized by the increasing incidence of fungal respiratory infections. Pseudallescheria boydii (P. boydii), an emerging pathogen of humans, is a filamentous fungus frequently isolated from the respiratory
Ghamrawi, S.; Renier, G.; Saulnier, P.; Cuenot, S.; Zykwinska, A.; Dutilh, B.E.; Thornton, C.; Faure, S.; Bouchara, J.P.
Progress in extending the life expectancy of cystic fibrosis (CF) patients remains jeopardized by the increasing incidence of fungal respiratory infections. Pseudallescheria boydii (P. boydii), an emerging pathogen of humans, is a filamentous fungus frequently isolated from the respiratory
Rita Colwell on "Experimental Reservoirs of Human Pathogens: The Vibrio cholerae paradigm" at the 2012 Sequencing, Finishing, Analysis in the Future Meeting held June 5-7, 2012 in Santa Fe, New Mexico.
Orengo Christine A
Full Text Available Abstract Background Protein Kinases are a superfamily of proteins involved in crucial cellular processes such as cell cycle regulation and signal transduction. Accordingly, they play an important role in cancer biology. To contribute to the study of the relation between kinases and disease we compared pathogenic mutations to neutral mutations as an extension to our previous analysis of cancer somatic mutations. First, we analyzed native and mutant proteins in terms of amino acid composition. Secondly, mutations were characterized according to their potential structural effects and finally, we assessed the location of the different classes of polymorphisms with respect to kinase-relevant positions in terms of subfamily specificity, conservation, accessibility and functional sites. Results Pathogenic Protein Kinase mutations perturb essential aspects of protein function, including disruption of substrate binding and/or effector recognition at family-specific positions. Interestingly these mutations in Protein Kinases display a tendency to avoid structurally relevant positions, what represents a significant difference with respect to the average distribution of pathogenic mutations in other protein families. Conclusions Disease-associated mutations display sound differences with respect to neutral mutations: several amino acids are specific of each mutation type, different structural properties characterize each class and the distribution of pathogenic mutations within the consensus structure of the Protein Kinase domain is substantially different to that for non-pathogenic mutations. This preferential distribution confirms previous observations about the functional and structural distribution of the controversial cancer driver and passenger somatic mutations and their use as a proxy for the study of the involvement of somatic mutations in cancer development.
Background. Human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and syphilis remain major infections around the world. In Angola, about 166 000 individuals are living with HIV, representing a prevalence of 1.98% in adults between 15 and 49 years of age. In a 2003 study in Luanda, 4.5% ...
lesions.[7,8] Among these, at least 15 are considered high‑risk. HPV (HR‑HPV) and are strongly associated with progression. Prevalence of Human Papillomavirus Type 58 in Women With or Without Cervical Lesions in. Northeast Brazil. Fernandes JV, Carvalho MGF1, de Fernandes TAAM2, Araújo JMG, Azevedo PRM3,.
Sero-prevalence of Human Immunodeficiency Virus and hepatitis viruses and their correlation with CD4 T-cell lymphocyte counts in pregnant women in the Buea Health District of Cameroon. Rebecca Enow Tanjong, Pride Teyim, Henry Lucien Kamga, Edwin Suh Neba, Theresia Nkuo-Akenji ...
This cross-sectional study describes the age-specific prevalence of human papillomavirus (HPV) infection and cytological abnormalities among this urban and peri-urban population. Method. Over the period March 2009 - September 2011, 1 524 women attending public sector primary healthcare clinics were invited to
Cervical cancer is the most common female cancer in northern Nigeria, yet the pattern of infection with human papillomavirus, the principal aetiologic agent is unknown. This was a preliminary study conducted in two referral hospitals in order to establish base-line data on the prevalence and risk factors for the infection in ...
AJRH Managing Editor
Agboghoroma et al. HIV Infection Diagnosed in Women in Labour. African Journal of Reproductive Health September 2015; 19 (3):137. ORIGINAL RESEARCH ARTICLE. The Prevalence of Human Immunodeficiency Virus Infection among. Pregnant Women in Labour with Unknown Status and those with. Negative status ...
Malaria and Human Immunodeficiency Virus (HIV) infections are major public health problems in Sub-Saharan Africa. Their overlapping geographical distribution and co-existence often result into high morbidity and mortality. This study was designed to establish the prevalence of Plasmodium falciparum malaria among HIV ...
Collado, M C; Meriluoto, J; Salminen, S
The aims of this study present were to assess and to evaluate in vitro the abilities of commercial probiotic strains derived from fermented milk products and related sources currently marketed in European countries, to inhibit, compete and displace the adhesion of selected potential pathogens to immobilized human mucus. The adhesion was assessed by measuring the radioactivity of bacteria adhered to the human mucus. We tested 12 probiotic strains against eight selected pathogens. All strains tested were able to adhere to mucus. All probiotic strains tested were able to inhibit and displace (P<0.05) the adhesion of Bacteroides, Clostridium, Staphylococcus and Enterobacter. In addition, the abilities to inhibit and to displace adhered pathogens depended on both the probiotic and the pathogen strains tested suggesting that several complementary mechanisms are implied in the processes. Our results indicate the need for a case-by-case assessment in order to select strains with the ability to inhibit or displace a specific pathogen. Probiotics could be useful to correct deviations observed in intestinal microbiota associated with specific diseases and also, to prevent pathogen infections. The competitive exclusion properties of probiotics as well as their ability to displace and inhibit pathogens are the most importance for therapeutic manipulation of the enteric microbiota. The application of such strategies could contribute to expand the beneficial properties on human health against pathogen infection.
Staley, Christopher; Reckhow, Kenneth H; Lukasik, Jerzy; Harwood, Valerie J
We investigated the potential for a variety of environmental reservoirs to harbor or contribute fecal indicator bacteria (FIB), DNA markers of human fecal contamination, and human pathogens to a freshwater lake. We hypothesized that submerged aquatic vegetation (SAV), sediments, and stormwater act as reservoirs and/or provide inputs of FIB and human pathogens to this inland water. Analysis included microbial source tracking (MST) markers of sewage contamination (Enterococcus faecium esp gene, human-associated Bacteroides HF183, and human polyomaviruses), pathogens (Salmonella, Cryptosporidium, Giardia, and enteric viruses), and FIB (fecal coliforms, Escherichia coli, and enterococci). Bayesian analysis was used to assess relationships among microbial and physicochemical variables. FIB in the water were correlated with concentrations in SAV and sediment. Furthermore, the correlation of antecedent rainfall and major rain events with FIB concentrations and detection of human markers and pathogens points toward multiple reservoirs for microbial contaminants in this system. Although pathogens and human-source markers were detected in 55% and 21% of samples, respectively, markers rarely coincided with pathogen detection. Bayesian analysis revealed that low concentrations (<45 CFU × 100 ml(-1)) of fecal coliforms were associated with 93% probability that pathogens would not be detected; furthermore the Bayes net model showed associations between elevated temperature and rainfall with fecal coliform and enterococci concentrations, but not E. coli. These data indicate that many under-studied matrices (e.g. SAV, sediment, stormwater) are important reservoirs for FIB and potentially human pathogens and demonstrate the usefulness of Bayes net analysis for water quality assessment. Copyright © 2012 Elsevier Ltd. All rights reserved.
Houldcroft, Charlotte J; Ramond, Jean-Baptiste; Rifkin, Riaan F; Underdown, Simon J
The biology of human migration can be observed from the co-evolutionary relationship with infectious diseases. While many pathogens are brief, unpleasant visitors to human bodies, others have the ability to become life-long human passengers. The story of a pathogen's genetic code may, therefore, provide insight into the history of its human host. The evolution and distribution of disease in Africa is of particular interest, because of the deep history of human evolution in Africa, the presence of a variety of non-human primates, and tropical reservoirs of emerging infectious diseases. This study explores which pathogens leave traces in the archaeological record, and whether there are realistic prospects that these pathogens can be recovered from sub-Saharan African archaeological contexts. Three stories are then presented of germs on a journey. The first is the story of HIV's spread on the back of colonialism and the railway networks over the last 150 years. The second involves the spread of Schistosoma mansoni, a parasite which shares its history with the trans-Atlantic slave trade and the origins of fresh-water fishing. Finally, we discuss the tantalising hints of hominin migration and interaction found in the genome of human herpes simplex virus 2. Evidence from modern African pathogen genomes can provide data on human behaviour and migration in deep time and contribute to the improvement of human quality-of-life and longevity.
de Mattos, Igor Medici; Soares, Ademilson E E; Tarpy, David R
Honey bee (Apis mellifera L.) populations have been experiencing notable mortality in Europe and North America. No single cause has been identified for these dramatic losses, but rather multiple interacting factors are likely responsible (such as pesticides, malnutrition, habitat loss, and pathogens). Paraquat is one of the most widely used non-selective herbicides, especially in developing countries. This herbicide is considered slightly toxic to honey bees, despite being reported as a highly effective inducer of oxidative stress in a wide range of living systems. Here, we test the effects of paraquat on the expression of detoxification and antioxidant-related genes, as well as on the dynamics of pathogen titers. Moreover, we tested the effects of pollen as mitigating factor to paraquat exposure. Our results show significant changes in the expression of several antioxidant-related and detoxification-related genes in the presence of paraquat, as well as an increase of pathogens titers. Finally, we demonstrate a mitigating effect of pollen through the up-regulation of specific genes and improvement of survival of bees exposed to paraquat. The presence of pollen in the diet was also correlated with a reduced prevalence of Nosema and viral pathogens. We discuss the importance of honey bees' nutrition, especially the availability of pollen, on colony losses chronically reported in the USA and Europe.
Borchardt, Mark A.; Burch, Tucker R
Dairy manure, like the fecal excrement from any domesticated or wild animal, can contain pathogens capable of infecting humans and causing illness or even death. Pathogens in dairy manure can be broadly divided into categories of taxonomy or infectiousness. Dividing by taxonomy there are three pathogen groups in dairy manure: viruses (e.g., bovine rotavirus), bacteria (e.g., Salmonella species), and protozoa (e.g., Cryptosporidium parvum). There are two categories of infectiousness for pathogens found in animals: those that are zoonotic and those that are not. A zoonotic pathogen is one that can infect both human and animal hosts. Some zoonotic pathogens found in dairy manure cause illness in both hosts (e.g., Salmonella) while other zoonotic pathogens, like Escherichia coli O157:H7, (enterohemorrhagic E. coli (EHEC)) cause illness only in humans. As a general rule, the gastrointestinal viruses found in dairy manure are not zoonotic. While there are exceptions (e.g., rare reports of bovine rotavirus infecting children), for the most part the viruses in dairy manure are not a human health concern. The primary concerns are the zoonotic bacteria and protozoa in dairy manure.
Gonzalez-Reiche, Ana S; Müller, Maria L; Ortiz, Lucía; Cordón-Rosales, Celia; Perez, Daniel R
Waterfowl species are known to harbor the greatest diversity of low pathogenicity influenza A virus (LPAIV) subtypes and are recognized as their main natural reservoir. In Guatemala there is evidence of circulation of LPAIV in wild ducks; however, the bird species contributing to viral diversity during the winter migration in Central America are unknown. In this study, samples obtained from 1250 hunter-killed birds from 22 different species were collected on the Pacific coast of Guatemala during three winter migration seasons between 2010 and 2013. Prevalence of LPAIV detected by real-time reverse-transcriptase polymerase chain reaction was 38.2%, 23.5%, and 24.7% in the 2010-11, 2011-12, and 2012-13 seasons, respectively. The highest virus prevalence was detected in the northern shoveler (Anas clypeata), followed by the blue-winged teal (Anas discors). The majority of positive samples and viral isolates were obtained from the blue-winged teal. Analysis of LPAIV prevalence over time in this species indicated a decreasing trend in monthly prevalence within a migration season. Sixty-eight viruses were isolated, and nine HA and seven NA subtypes were identified in 19 subtype combinations. In 2012-13 the most prevalent subtype was H14, a subtype identified for the first time in the Western Hemisphere in 2010. The results from this study represent the most detailed description available to date of LPAIV circulation in Central America.
Chen, Kang Mei; Stephen, Josena K; Ghanem, Tamer; Stachler, Robert; Gardner, Glendon; Jones, Lamont; Schweitzer, Vanessa P; Hall, Francis; Divine, George; Worsham, Maria J
The goal was to determine the prevalence of high-risk HPV16 using saliva in a screening population in Detroit, Michigan. Real-time quantitative polymerase chain reaction was applied to detect HPV16 in saliva DNA from 349 screening subjects without head and neck cancer (HNC), 156 with HNC, and 19 controls. Cut points for human papilloma virus (HPV) positivity were >0 and >0.001 copy/cell. Proportions were compared between groups using exact χ(2) or Fisher exact tests (P 0, each group had an overall HPV prevalence of more than 5%, with a higher prevalence of 30.8% in the HNC patient group. At a cut point >0.001, the prevalence was lower: 0% in the control, 1.2% in the screening, and 16.7% in the HNC group. In the latter, for both cut points, HPV prevalence was different across sites (0, women in the screening group had a higher prevalence of HPV than did men (P = .010), and at >0.001, the prevalence was higher for men in the HNC group than for women (P = .035). In the screening group, at >0, only African Americans had a higher prevalence than Caucasian Americans (P = .025). In the screening group, a 6.9% and 1.2% screening rate was noted at cut points >0 and >0.001, respectively. The results provide data to inform public health considerations of the feasibility of saliva as a screening tool in at-risk populations with the long-term goal of prophylactic vaccination against oral HPV.
van Baarlen, Peter; van Belkum, Alex; Thomma, Bart P H J
Relatively simple eukaryotic model organisms such as the genetic model weed plant Arabidopsis thaliana possess an innate immune system that shares important similarities with its mammalian counterpart. In fact, some human pathogens infect Arabidopsis and cause overt disease with human symptomology. In such cases, decisive elements of the plant's immune system are likely to be targeted by the same microbial factors that are necessary for causing disease in humans. These similarities can be exploited to identify elementary microbial pathogenicity factors and their corresponding targets in a green host. This circumvents important cost aspects that often frustrate studies in humans or animal models and, in addition, results in facile ethical clearance.
Rivera, Fulton P.; Ochoa, Theresa J.; Ruiz, Joaquim; Medina, Anicia M.; Ecker, Lucie; Mercado, Erik; Gil, Ana I.; Huicho, Luis; Lanata, Claudio F.
Summary Norovirus was detected in 17.4% of 224 diarrhoeal samples from children younger than 24 months of age in Lima, in whom all common pathogens had been excluded (pathogen negative). Norovirus was identified more frequently in children older than 12 months of age than in younger children (34% vs 8%, P<0.001). Among norovirus-positive samples, genogroup II was the predominant group (92%). Compared with rotavirus, norovirus episodes tended to be of shorter duration and less severe. The role of norovirus as a cause of diarrhoea and the ascertainment of its severity in developing countries needs further confirmation by future epidemiological studies. PMID:21962615
Vítovec, J.; Hamadejová, K.; Landová, L.; Kváč, Martin; Květoňová, Dana; Sak, Bohumil
Roč. 53, č. 5 (2006), s. 239-243 ISSN 0931-1793 R&D Projects: GA ČR GA524/05/0992 Institutional research plan: CEZ:AV0Z60220518 Keywords : Cryptosporidium suis * piglets * pathogenicity Subject RIV: EG - Zoology Impact factor: 1.356, year: 2006
Bai, Y.; Kosoy, M.Y.; Calisher, C.H.; Cully, J.F.; Collinge, S.K.
By studying Bartonella prevalence in rodent communities from 23 geographic sites in the western United States and one site in northern Mexico, the present study focused on the effects of rodent community diversity (measured by richness and Shannon index) and composition on prevalence of Bartonella infections. The analysis showed negative correlations of Bartonella prevalence with rodent richness and Shannon index. Further, Bartonella prevalence varied among rodent genera/species. Three models were applied to explain the observations. (1) Within-species/genus transmission: Bartonella strains usually are host-specific and adding non-host species would decrease Bartonella prevalence in its principal host through reduction of host contact (encounter reduction); (2) Frequency-dependence: Adding hosts would decrease the proportion of all infected individuals in the community, resulting in a reduction in the number of contacts between susceptible and infected individuals that usually leads to transmission (transmission reduction); and (3) Dominant species effect: Dominant species, if not susceptible to Bartonellae, can constrain the abundance of susceptible hosts (susceptible host regulation). These mechanisms work in concert; and the level of Bartonella prevalence is an outcome of regulation of all of these mechanisms on the entire system.
Wijnands, Lucas M; Delfgou-van Asch, Ellen H M; Beerepoot-Mensink, Marieke E; van der Meij-Florijn, Alice; Fitz-James, Ife; van Leusden, Frans M; Pielaat, Annemarie
Recent outbreaks with vegetable or fruits as vehicles have raised interest in the characterization of the public health risk due to microbial contamination of these commodities. Because qualitative and quantitative data regarding prevalence and concentration of various microbes are lacking, we conducted a survey to estimate the prevalence and contamination level of raw produce and the resulting minimally processed packaged salads as sold in The Netherlands. A dedicated sampling plan accounted for the amount of processed produce in relation to the amount of products, laboratory capacity, and seasonal influences. Over 1,800 samples of produce and over 1,900 samples of ready-to-eat mixed salads were investigated for Salmonella enterica serovars, Campylobacter spp., Escherichia coli O157, and Listeria monocytogenes. The overall prevalence in raw produce varied between 0.11% for E. coli O157 and L. monocytogenes and 0.38% for Salmonella. Prevalence point estimates for specific produce/pathogen combinations ranged for Salmonella from 0.53% in iceberg lettuce to 5.1% in cucumber. For Campylobacter, this ranged from 0.83% in endive to 2.7% in oak tree lettuce. These data will be used to determine the public health risk posed by the consumption of ready-to-eat mixed salads in The Netherlands.
Full Text Available BACKGROUND: Australia relies heavily on rabbit haemorrhagic disease virus (RHDV for the biological control of introduced European wild rabbits Oryctolagus cuniculus, which are significant economic and environmental pests. An endemic non-pathogenic rabbit calicivirus termed RCV-A1 also occurs in wild rabbits in Australian and provides partial protection against lethal RHDV infection, thus interfering with effective rabbit control. Despite its obvious importance for rabbit population management, little is known about the epidemiology of this benign rabbit calicivirus. METHODS: We determined the continent-wide distribution and prevalence of RCV-A1 by analysing 1,805 serum samples from wild rabbit populations at 78 sites across Australia for the presence of antibodies to RCV-A1 using a serological test that specifically detects RCV-A1 antibodies and does not cross-react with co-occurring RHDV antibodies. We also investigated possible correlation between climate variables and prevalence of RCV-A1 by using generalised linear mixed effect models. RESULTS: Antibodies to RCV-A1 were predominantly detected in rabbit populations in cool, high rainfall areas of the south-east and south-west of the continent. There was strong support for modelling RCV-A1 prevalence as a function of average annual rainfall and minimum temperature. The best ranked model explained 26% of the model structural deviance. According to this model, distribution and prevalence of RCV-A1 is positively correlated with periods of above average rainfall and negatively correlated with periods of drought. IMPLICATIONS: Our statistical model of RCV-A1 prevalence will greatly increase our understanding of RCV-A1 epidemiology and its interaction with RHDV in Australia. By defining the environmental conditions associated with the prevalence of RCV-A1, it also contributes towards understanding the distribution of similar viruses in New Zealand and Europe.
Fazzina, R; Iudicone, P; Mariotti, A; Fioravanti, D; Procoli, A; Cicchetti, E; Scambia, G; Bonanno, G; Pierelli, L
Alternatives to the use of fetal bovine serum (FBS) have been investigated to ensure xeno-free growth condition. In this study we evaluated the efficacy of human platelet lysate (PL) as a substitute of FBS for the in vitro culture of some human cell lines. PL was obtained by pools of pathogen inactivated human donor platelet (PLT) concentrates. Human leukemia cell lines (KG-1, K562, JURKAT, HL-60) and epithelial tumor cell lines (HeLa and MCF-7) were cultured with either FBS or PL. Changes in cell proliferation, viability, morphology, surface markers and cell cycle were evaluated for each cell line. Functional characteristics were analysed by drug sensitivity test and cytotoxicity assay. Our results demonstrated that PL can support growth and expansion of all cell lines, although the cells cultured in presence of PL experienced a less massive proliferation compared to those grown with FBS. We found a comparable percentage of viable specific marker-expressing cells in both conditions, confirming lineage fidelity in all cultures. Functionality assays showed that cells in both FBS- and PL-supported cultures maintained their normal responsiveness to adriamycin and NK cell-mediated lysis. Our findings indicate that PL is a feasible serum substitute for supporting growth and propagation of haematopoietic and epithelial cell lines with many advantages from a perspective of process standardization, ethicality and product safety.
Full Text Available Infectious disease has shaped the natural genetic diversity of humans throughout the world. A new approach to capture positive selection driven by pathogens would provide information regarding pathogen exposure in distinct human populations and the constantly evolving arms race between host and disease-causing agents. We created a human pathogen interaction database and used the integrated haplotype score (iHS to detect recent positive selection in genes that interact with proteins from 26 different pathogens. We used the Human Genome Diversity Panel to identify specific populations harboring pathogen-interacting genes that have undergone positive selection. We found that human genes that interact with 9 pathogen species show evidence of recent positive selection. These pathogens are Yersenia pestis, human immunodeficiency virus (HIV 1, Zaire ebolavirus, Francisella tularensis, dengue virus, human respiratory syncytial virus, measles virus, Rubella virus, and Bacillus anthracis. For HIV-1, GWAS demonstrate that some naturally selected variants in the host-pathogen protein interaction networks continue to have functional consequences for susceptibility to these pathogens. We show that selected human genes were enriched for HIV susceptibility variants (identified through GWAS, providing further support for the hypothesis that ancient humans were exposed to lentivirus pandemics. Human genes in the Italian, Miao, and Biaka Pygmy populations that interact with Y. pestis show significant signs of selection. These results reveal some of the genetic footprints created by pathogens in the human genome that may have left lasting marks on susceptibility to infectious disease.
Qi, Wenbao; Jia, Weixin; Liu, Di; Li, Jing; Bi, Yuhai; Xie, Shumin; Li, Bo; Hu, Tao; Du, Yingying; Xing, Li; Zhang, Jiahao; Zhang, Fuchun; Wei, Xiaoman; Eden, John-Sebastian; Li, Huanan; Tian, Huaiyu; Li, Wei; Su, Guanming; Lao, Guangjie; Xu, Chenggang; Xu, Bing; Liu, Wenjun; Zhang, Guihong; Ren, Tao; Holmes, Edward C; Cui, Jie; Shi, Weifeng; Gao, George F; Liao, Ming
Since its emergence in 2013, the H7N9 low-pathogenic avian influenza virus (LPAIV) has been circulating in domestic poultry in China, causing five waves of human infections. A novel H7N9 highly pathogenic avian influenza virus (HPAIV) variant possessing multiple basic amino acids at the cleavage site of the hemagglutinin (HA) protein was first reported in two cases of human infection in January 2017. More seriously, those novel H7N9 HPAIV variants have been transmitted and caused outbreaks on poultry farms in eight provinces in China. Herein, we demonstrate the presence of three different amino acid motifs at the cleavage sites of these HPAIV variants which were isolated from chickens and humans and likely evolved from the preexisting LPAIVs. Animal experiments showed that these novel H7N9 HPAIV variants are both highly pathogenic in chickens and lethal to mice. Notably, human-origin viruses were more pathogenic in mice than avian viruses, and the mutations in the PB2 gene associated with adaptation to mammals (E627K, A588V, and D701N) were identified by next-generation sequencing (NGS) and Sanger sequencing of the isolates from infected mice. No polymorphisms in the key amino acid substitutions of PB2 and HA in isolates from infected chicken lungs were detected by NGS. In sum, these results highlight the high degree of pathogenicity and the valid transmissibility of this new H7N9 variant in chickens and the quick adaptation of this new H7N9 variant to mammals, so the risk should be evaluated and more attention should be paid to this variant. IMPORTANCE Due to the recent increased numbers of zoonotic infections in poultry and persistent human infections in China, influenza A(H7N9) virus has remained a public health threat. Most of the influenza A(H7N9) viruses reported previously have been of low pathogenicity. Now, these novel H7N9 HPAIV variants have caused human infections in three provinces and outbreaks on poultry farms in eight provinces in China. We analyzed
Christine P Zolnik
Full Text Available Pathogen prevalence within blacklegged ticks (Ixodes scapularis Say, 1821 tends to vary across sites and geographic regions, but the underlying causes of this variation are not well understood. Efforts to understand the ecology of Lyme disease have led to the proposition that sites with higher host diversity will result in lower disease risk due to an increase in the abundance of inefficient reservoir species relative to the abundance of species that are highly competent reservoirs. Although the Lyme disease transmission cycle is often cited as a model for this "dilution effect hypothesis", little empirical evidence exists to support that claim. Here we tested the dilution effect hypothesis for two pathogens transmitted by the blacklegged tick along an urban-to-rural gradient in the northeastern United States using landscape fragmentation as a proxy for host biodiversity. Percent impervious surface and habitat fragment size around each site were determined to assess the effect of landscape fragmentation on nymphal blacklegged tick infection with Borrelia burgdorferi and Anaplasma phagocytophilum. Our results do not support the dilution effect hypothesis for either pathogen and are in agreement with the few studies to date that have tested this idea using either a landscape proxy or direct measures of host biodiversity.
van der Veen, Stijn; Tang, Christoph M
During colonization and disease, bacterial pathogens must survive the onslaught of the host immune system. A key component of the innate immune response is the generation of reactive oxygen and nitrogen species by phagocytic cells, which target and disrupt pathogen molecules, particularly DNA, and the base excision repair (BER) pathway is the most important mechanism for the repair of such oxidative DNA damage. In this Review, we discuss how the human-specific pathogens Mycobacterium tuberculosis, Helicobacter pylori and Neisseria meningitidis have evolved specialized mechanisms of DNA repair, particularly their BER pathways, compared with model organisms such as Escherichia coli. This specialization in DNA repair is likely to reflect the distinct niches occupied by these important human pathogens in the host.
Huang, Yannan; Hansen, Lisbeth Truelstrup; Ragush, Colin M.
Wastewater stabilization ponds (WSPs) are commonly used to treat municipal wastewater in Arctic Canada. The biological treatment in the WSPs is strongly influenced by climatic conditions. Currently, there is limited information about the removal of fecal and pathogenic bacteria during the short...... cool summer treatment season. With relevance to public health, the objectives of this paper were to determine if treatment in arctic WSPs resulted in the disinfection (i.e., removal of fecal indicator bacteria, Escherichia coli) and removal of selected human bacterial pathogens from the treated...... treatment of the wastewater with a 2â€“3 Log removal of generic indicator E. coli. The bacterial pathogens Salmonella spp., pathogenic E. coli, and Listeria monocytogenes, but not Campylobacter spp. and Helicobacter pylori, were detected in the untreated and treated wastewater, indicating that human...
Andreatta, Massimo; Nielsen, Morten; Aarestrup, Frank Møller
to be able to separate pathogenic organisms from non-pathogenic ones. Using traditional experimental methods for this purpose can be very costly and time-consuming, and also uncertain since animal models are not always good predictors for pathogenicity in humans. Bioinformatics-based methods are therefore...... tested. An additional validation on an independent test-set assigned correctly 22 out of 24 bacteria. Conclusions: The proposed approach was demonstrated to go beyond the species bias imposed by evolutionary relatedness, and performs better than predictors based solely on taxonomy or sequence similarity...
Elhadi, Nasreldin; Radu, Son; Chen, Chien-Hsien; Nishibuchi, Mitsuaki
Seafood samples obtained in seafood markets and supermarkets at 11 sites selected from four states in Malaysia were examined for the presence of nine potentially pathogenic species from the genus Vibrio between July 1998 and June 1999. We examined 768 sample sets that included shrimp, squid, crab, cockles, and mussels. We extensively examined shrimp samples from Selangor State to determine seasonal variation of Vibrio populations. Eight potentially pathogenic Vibrio species were detected, with overall incidence in the samples at 4.6% for V. cholerae, 4.7% for V. parahaemolyticus, 6.0% for V. vulnificus, 11% for V. alginolyticus, 9.9% for V. metschnikovii, 1.3% for V. mimicus, 13% for V. damsela, 7.6% for V. fluvialis, and 52% for a combined population of all of the above. As many as eight Vibrio species were detected in shrimp and only four in squid and peel mussels. The overall percent incidence of any of the eight vibrios was highest (82%) in cockles (Anadara granosa) among the seafoods examined and was highest (100%) in Kuching, Sarawak State, and lowest (25%) in Penang, Pulau Penang State, among the sampling sites. Of 97 strains of V. cholerae isolated, one strain belonged to the O1 serotype and 14 to the O139 serotype. The results indicate that the various seafood markets in Malaysia are contaminated with potentially pathogenic Vibrio species regardless of the season and suggest that there is a need for adequate consumer protection measures.
Reedy, Jennifer L; Bastidas, Robert J; Heitman, Joseph
The Second FEBS Advanced Lecture Course on Human Fungal Pathogens: Molecular Mechanisms of Host-Pathogen Interactions and Virulence, organized by Christophe d'Enfert (Institut Pasteur, France), Anita Sil (UCSF, USA), and Steffen Rupp (Fraunhofer, IGB, Germany), occurred May 2007 in La Colle sur Loup, France. Here we review the advances presented and the current state of knowledge in key areas of fungal pathogenesis.
Muñoz, José F.; Gauthier, Gregory M.; Desjardins, Christopher A.; Gallo, Juan E.; Holder, Jason; Sullivan, Thomas D.; Marty, Amber J.; Carmen, John C.; Chen, Zehua; Ding, Li; Gujja, Sharvari; Magrini, Vincent; Misas, Elizabeth; Mitreva, Makedonka; Priest, Margaret
Three closely related thermally dimorphic pathogens are causal agents of major fungal diseases affecting humans in the Americas: blastomycosis, histoplasmosis and paracoccidioidomycosis. Here we report the genome sequence and analysis of four strains of the etiological agent of blastomycosis, Blastomyces, and two species of the related genus Emmonsia, typically pathogens of small mammals. Compared to related species, Blastomyces genomes are highly expanded, with long, often sharply demarcated...
A legacy of low-impact logging does not elevate prevalence of potentially pathogenic protozoa in free-ranging gorillas and chimpanzees in the Republic of Congo: logging and parasitism in African apes.
Gillespie, Thomas R; Morgan, David; Deutsch, J Charlie; Kuhlenschmidt, Mark S; Salzer, Johanna S; Cameron, Kenneth; Reed, Trish; Sanz, Crickette
Many studies have examined the long-term effects of selective logging on the abundance and diversity of free-ranging primates. Logging is known to reduce the abundance of some primate species through associated hunting and the loss of food trees for frugivores; however, the potential role of pathogens in such primate population declines is largely unexplored. Selective logging results in a suite of alterations in host ecology and forest structure that may alter pathogen dynamics in resident wildlife populations. In addition, environmental pollution with human fecal material may present a risk for wildlife infections with zoonotic protozoa, such as Cryptosporidium and Giardia. To better understand this interplay, we compared patterns of infection with these potentially pathogenic protozoa in sympatric western lowland gorillas (Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes troglodytes) in the undisturbed Goualougo Triangle of Nouabalé-Ndoki National Park and the adjacent previously logged Kabo Concession in northern Republic of Congo. No Cryptosporidium infections were detected in any of the apes examined and prevalence of infection with Giardia was low (3.73% overall) and did not differ between logged and undisturbed forest for chimpanzees or gorillas. These results provide a baseline for prevalence of these protozoa in forest-dwelling African apes and suggest that low-intensity logging may not result in long-term elevated prevalence of potentially pathogenic protozoa.
Abdelwhab, E M; Veits, J; Mettenleiter, T C
The H7 subtype HA gene has been found in combination with all nine NA subtype genes. Most exhibit low pathogenicity and only rarely high pathogenicity in poultry (and humans). During the past few years infections of poultry and humans with H7 subtypes have increased markedly. This review summarizes the emergence of avian influenza virus H7 subtypes in birds and humans, and the possibilities of its control in poultry. All H7Nx combinations were reported from wild birds, the natural reservoir of the virus. Geographically, the most prevalent subtype is H7N7, which is endemic in wild birds in Europe and was frequently reported in domestic poultry, whereas subtype H7N3 is mostly isolated from the Americas. In humans, mild to fatal infections were caused by subtypes H7N2, H7N3, H7N7 and H7N9. While infections of humans have been associated mostly with exposure to domestic poultry, infections of poultry have been linked to wild birds or live-bird markets. Generally, depopulation of infected poultry was the main control tool; however, inactivated vaccines were also used. In contrast to recent cases caused by subtype H7N9, human infections were usually self-limiting and rarely required antiviral medication. Close genetic and antigenic relatedness of H7 viruses of different origins may be helpful in development of universal vaccines and diagnostics for both animals and humans. Due to the wide spread of H7 viruses and their zoonotic importance more research is required to better understand the epidemiology, pathobiology and virulence determinants of these viruses and to develop improved control tools.
Full Text Available The dematiaceous (melanised fungus Lomentospora (Scedosporium prolificans is a life-threatening opportunistic pathogen of immunocompromised humans, resistant to anti-fungal drugs. Melanin has been shown to protect human pathogenic fungi against antifungal drugs, oxidative killing and environmental stresses. To determine the protective role of melanin in L. prolificans to oxidative killing (H2O2, UV radiation and the polyene anti-fungal drug amphotericin B, targeted gene disruption was used to generate mutants of the pathogen lacking the dihydroxynaphthalene (DHN-melanin biosynthetic enzymes polyketide synthase (PKS1, tetrahydroxynapthalene reductase (4HNR and scytalone dehydratase (SCD1. Infectious propagules (spores of the wild-type strain 3.1 were black/brown, whereas spores of the PKS-deficient mutant ΔLppks1::hph were white. Complementation of the albino mutant ΔLppks1::hph restored the black-brown spore pigmentation, while the 4HNR-deficient mutant ΔLp4hnr::hph and SCD-deficient mutant ΔLpscd1::hph both produced orange-yellow spores. The mutants ΔLppks1::hph and ΔLp4hnr::hph showed significant reductions in spore survival following H2O2 treatment, while spores of ΔLpscd1::hph and the ΔLppks1::hph complemented strain ΔLppks1::hph:PKS showed spore survivals similar to strain 3.1. Spores of the mutants ΔLp4hnr::hph and ΔLpscd1::hph and complemented strain ΔLppks1::hph:PKS showed spore survivals similar to 3.1 following exposure to UV radiation, but survival of ΔLppks1::hph spores was significantly reduced compared to the wild-type strain. Strain 3.1 and mutants ΔLp4hnr::hph and ΔLppks1::hph:PKS were resistant to amphotericin B while, paradoxically, the PKS1- and SCD1-deficient mutants showed significant increases in growth in the presence of the antifungal drug. Taken together, these results show that while melanin plays a protective role in the survival of the pathogen to oxidative killing and UV radiation, melanin does not
Al-Laaeiby, Ayat; Kershaw, Michael J; Penn, Tina J; Thornton, Christopher R
The dematiaceous (melanised) fungus Lomentospora (Scedosporium) prolificans is a life-threatening opportunistic pathogen of immunocompromised humans, resistant to anti-fungal drugs. Melanin has been shown to protect human pathogenic fungi against antifungal drugs, oxidative killing and environmental stresses. To determine the protective role of melanin in L. prolificans to oxidative killing (H₂O₂), UV radiation and the polyene anti-fungal drug amphotericin B, targeted gene disruption was used to generate mutants of the pathogen lacking the dihydroxynaphthalene (DHN)-melanin biosynthetic enzymes polyketide synthase (PKS1), tetrahydroxynapthalene reductase (4HNR) and scytalone dehydratase (SCD1). Infectious propagules (spores) of the wild-type strain 3.1 were black/brown, whereas spores of the PKS-deficient mutant ΔLppks1::hph were white. Complementation of the albino mutant ΔLppks1::hph restored the black-brown spore pigmentation, while the 4HNR-deficient mutant ΔLp4hnr::hph and SCD-deficient mutant ΔLpscd1::hph both produced orange-yellow spores. The mutants ΔLppks1::hph and ΔLp4hnr::hph showed significant reductions in spore survival following H₂O₂ treatment, while spores of ΔLpscd1::hph and the ΔLppks1::hph complemented strain ΔLppks1::hph:PKS showed spore survivals similar to strain 3.1. Spores of the mutants ΔLp4hnr::hph and ΔLpscd1::hph and complemented strain ΔLppks1::hph:PKS showed spore survivals similar to 3.1 following exposure to UV radiation, but survival of ΔLppks1::hph spores was significantly reduced compared to the wild-type strain. Strain 3.1 and mutants ΔLp4hnr::hph and ΔLppks1::hph:PKS were resistant to amphotericin B while, paradoxically, the PKS1- and SCD1-deficient mutants showed significant increases in growth in the presence of the antifungal drug. Taken together, these results show that while melanin plays a protective role in the survival of the pathogen to oxidative killing and UV radiation, melanin does not
Kathryn Patterson Sutherland
Full Text Available Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS, a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments were conducted with A. palmata maintained in closed aquaria to determine infectivity of strain PDR60 from reef and wastewater sources. Strain PDR60 from wastewater and diseased A. palmata caused disease signs in elkhorn coral in as little as four and five days, respectively, demonstrating that wastewater is a definitive source of APS and identifying human strain PDR60 as a coral pathogen through fulfillment of Koch's postulates. A. palmata inoculated with strain PDR60 from C. abbreviata showed limited virulence, with one of three inoculated fragments developing APS signs within 13 days. Strain PDR60 from non-host coral S. siderea showed a delayed pathogenic effect, with disease signs developing within an average of 20 days. These results suggest that C. abbreviata and non-host corals may function as reservoirs or vectors of the APS pathogen. Our results provide the first example of a marine "reverse zoonosis" involving the transmission of a human pathogen (S. marcescens to a marine invertebrate (A. palmata. These findings underscore the interaction between public health practices and environmental health indices such as coral reef survival.
Sutherland, Kathryn Patterson; Shaban, Sameera; Joyner, Jessica L; Porter, James W; Lipp, Erin K
Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments were conducted with A. palmata maintained in closed aquaria to determine infectivity of strain PDR60 from reef and wastewater sources. Strain PDR60 from wastewater and diseased A. palmata caused disease signs in elkhorn coral in as little as four and five days, respectively, demonstrating that wastewater is a definitive source of APS and identifying human strain PDR60 as a coral pathogen through fulfillment of Koch's postulates. A. palmata inoculated with strain PDR60 from C. abbreviata showed limited virulence, with one of three inoculated fragments developing APS signs within 13 days. Strain PDR60 from non-host coral S. siderea showed a delayed pathogenic effect, with disease signs developing within an average of 20 days. These results suggest that C. abbreviata and non-host corals may function as reservoirs or vectors of the APS pathogen. Our results provide the first example of a marine "reverse zoonosis" involving the transmission of a human pathogen (S. marcescens) to a marine invertebrate (A. palmata). These findings underscore the interaction between public health practices and environmental health indices such as coral reef survival.
Parnell, S; Gottwald, T R; Cunniffe, N J; Alonso Chavez, V; van den Bosch, F
Emerging plant pathogens are a significant problem for conservation and food security. Surveillance is often instigated in an attempt to detect an invading epidemic before it gets out of control. Yet in practice many epidemics are not discovered until already at a high prevalence, partly due to a lack of quantitative understanding of how surveillance effort and the dynamics of an invading epidemic relate. We test a simple rule of thumb to determine, for a surveillance programme taking a fixed number of samples at regular intervals, the distribution of the prevalence an epidemic will have reached on first discovery (discovery-prevalence) and its expectation E(q*). We show that E(q*) = r/(N/Δ), i.e. simply the rate of epidemic growth divided by the rate of sampling; where r is the epidemic growth rate, N is the sample size and Δ is the time between sampling rounds. We demonstrate the robustness of this rule of thumb using spatio-temporal epidemic models as well as data from real epidemics. Our work supports the view that, for the purposes of early detection surveillance, simple models can provide useful insights in apparently complex systems. The insight can inform decisions on surveillance resource allocation in plant health and has potential applicability to invasive species generally. © 2015 The Author(s).
Köck, R; Werner, P; Friedrich, A W; Fegeler, C; Becker, K
The nares represent an important bacterial reservoir for endogenous infections. This study aimed to assess the prevalence of nasal colonization by different important pathogens, the associated antimicrobial susceptibility and risk factors. We performed a prospective cohort study among 1878
A Mark Ibekwe
Full Text Available Current microbial source tracking (MST methods for water depend on testing for fecal indicator bacterial counts or specific marker gene sequences to identify fecal contamination where potential human pathogenic bacteria could be present. In this study, we applied 454 high-throughput pyrosequencing to identify bacterial pathogen DNA sequences, including those not traditionally monitored by MST and correlated their abundances to specific sources of contamination such as urban runoff and agricultural runoff from concentrated animal feeding operations (CAFOs, recreation park area, waste-water treatment plants, and natural sites with little or no human activities. Samples for pyrosequencing were surface water, and sediment collected from 19 sites. A total of 12,959 16S rRNA gene sequences with average length of ≤400 bp were obtained, and were assigned to corresponding taxonomic ranks using ribosomal database project (RDP, Classifier and Greengenes databases. The percent of total potential pathogens were highest in urban runoff water (7.94%, agricultural runoff sediment (6.52%, and Prado Park sediment (6.00%, respectively. Although the numbers of DNA sequence tags from pyrosequencing were very high for the natural site, corresponding percent potential pathogens were very low (3.78-4.08%. Most of the potential pathogenic bacterial sequences identified were from three major phyla, namely, Proteobacteria, Bacteroidetes, and Firmicutes. The use of deep sequencing may provide improved and faster methods for the identification of pathogen sources in most watersheds so that better risk assessment methods may be developed to enhance public health.
D Leshan Wannigama
Full Text Available Cockroaches are among the medically important pests found within the human habitations that cause serious public health problems. They may harbor a number of pathogenic bacteria on the external surface with antibiotic resistance. Hence, they are regarded as major microbial vectors. This study investigates the prevalence and antibiotic resistance of Gram-negative pathogenic bacteria species isolated from Periplaneta americana and Blattella germanica in Varanasi, India.Totally, 203 adult cockroaches were collected form 44 households and 52 food-handling establishments by trapping. Bacteriological examination of external surfaces of Pe. americana and Bl. germanica were carried out using standard method and antibiotics susceptibility profiles of the isolates were determined using Kirby-Bauer disc diffusion methods.Among the places, we found that 54% had cockroache infestation in households and 77% in food- handling establishments. There was no significant different between the overall bacteria load of the external surface in Pe. americana (64.04% and Bl. germanica (35.96%. However the predominant bacteria on cockroaches were Klebsiella pneumonia, Escherichia coli, Enterobacter aerogenes, and Pseudomonas aeruginosa. However, Kl. pneumoniae and Ps. aeruginosa were the most prevalent, drug-resistant strains were isolated from the cockroaches with 100% resistance to sulfamethoxazole/trimethoprim and ampicillin. For individual strains of bacteria, Escherichia coli was found to have multi-resistance to four antibiotic tested, Citrobacter freundii four, Enterobacter aerogenes and Proteus mirabilis to three.Cockroaches are uniformly distributed in domestic environment, which can be a possible vector for transmission of drug-resistant bacteria and food-borne diseases.
Full Text Available Espen Enerly, Cecilia Olofsson, Mari NygårdDepartment of Research, Cancer Registry of Norway, Oslo, NorwayAbstract: Human papillomavirus (HPV is the main cause of cervical cancer, and many countries now offer vaccination against HPV to girls by way of government-funded national immunization programs. Monitoring HPV prevalence in adolescents could offer a near-term biological measure of vaccine impact, and urine sampling may be an attractive large-scale method that could be used for this purpose. Our objective was to provide an overview of the literature on HPV DNA detection in urine samples, with an emphasis on adolescents. We searched the PubMed database using the terms “HPV” and “urine” and identified 21 female and 14 male study populations in which HPV prevalence in urine samples was reported, four of which included only asymptomatic female adolescents. We provide herein an overview of the recruitment setting, age, urine sampling procedure, lesion type, HPV assay, and HPV prevalence in urine samples and other urogenital samples for the studies included in this review. In female study populations, concordance for any HPV type and type-specific concordance in paired urine and cervical samples are provided in addition to sensitivity and specificity. We concluded that few studies on HPV prevalence in urine samples have been performed in asymptomatic female adolescent populations but that urine samples may be a useful alternative to cervical samples to monitor changes in HPV prevalence in females in the post-HPV vaccination era. However, care should be taken when extrapolating HPV findings from urine samples to the cervix. In males, urine samples do not seem to be optimal for monitoring HPV prevalence due to a low human genomic DNA content and HPV DNA detection rate compared to other urogenital sites. In each situation the costs and benefits of HPV DNA detection in urine compared to alternative monitoring options should be carefully
Kim, M J; Kim, S A; Kang, Y S; Hwang, I G; Rhee, M S
Aerobic plate counts (APC), coliforms, Bacillus cereus, Escherichia coli and eight foodborne pathogens were tested in 1008 cheap and junk foods, including candies, dried cakes, chewing gum, chocolate, dried and seasoned seafood, ice cream, and sugary foods. APCs were positive for 342 samples (33·9%), and the majority of the counts were 2-3 log CFU g(-1) or ml(-1) (average: 1·10 log CFU g(-1) or ml(-1) ). Most samples (97·3%) contained no coliforms (average: 0·07 log CFU g(-1) or ml(-1) ). Bacillus cereus was detected in 68 samples (average: 0·14 log CFU g(-1) or ml(-1) ). Escherichia coli and Listeria monocytogenes were detected in 6 and 1 samples, respectively, whereas other foodborne pathogens were not isolated. The highest bacterial counts were associated with dried and seasoned seafood products and dried cakes, suggesting that appropriate regulations of these food types should be considered. Cheap and junk foods were produced mainly in developing countries, but there were no significant differences in the bacterial counts among different countries of origin. The presence of foodborne pathogens may pose a risk for children. These results suggest that there is cause for deeper concern about the safety of these foods and that effective countermeasures should be established to improve their microbiological safety. Food safety is especially important for children, but only limited information is available about the microbiological quality of cheap and junk foods that are consumed frequently by primary schoolchildren (e.g. dried cakes, candies and chocolates). The present study investigated the microbial quality of cheap and junk foods, and our results indicate that these foods are a potential health risk for children, therefore, deeper concern about the safety of these foods and effective countermeasures should be established to improve their microbiological safety. The present study may contribute to the development of an appropriate child food
Full Text Available Mastitis in cows, one of the most common and economically important infectious diseases of dairy cattle, all over the world, with significant impact due to economic losses, occurs when the udder becomes inflamed because the leukocytes are released into the mammary gland usually in response to bacteria invasion of the teat canal. The main objective of this study was to evaluate the in vitro antimicrobial susceptibility of bacteria isolated from milk in order to design specific control programs for bovine mastitis in this area. A total of 204 milk samples aseptically collected both from farms and private owners were processed during May 2014 and March 2016 within the Microbiology Laboratory of the Faculty of Veterinary Cluj-Napoca, Romania. The microbiological examination was carried out by inoculation on blood agar and MacConkey medium. After the overnight incubation in aerobic conditions, the identification of the isolates was performed using microscopic, cultural and biochemical methods. Biochemical identification was based on API 20 Biomerieux system. Susceptibility to antibiotics was evaluated using Kirby Bauer disk diffusion method on Mueller-Hinton agar; the antibiotics were represented by Amoxicillin and Clavulanic Acid, Ceftiofur, Florfenicol, Mastidiscs, Enrofloxacin, Penicillin and Tetracycline. Staphylococcus spp. was the most common isolated pathogen, in 54.9% of the specimens, followed by Streptococcus spp. in 20.1%, Escherichia coli in 10.78%, Klebsiella spp. in 8.34%, Bacillus spp. in 5.88%. The most frequent associations were represented by staphylococci-streptococci in 62.7% of the samples, followed by streptococci-bacillus in 19.8% of the samples. The most important etiological agents identified were Staphylococcus aureus, S uberis, Streptococcus agalactiae, and Escherichia coli. Antimicrobial susceptibility test for the total isolates revealed good sensitivity to Enrofloxacin, Mastidiscs and Amoxicillin and Clavulanic Acid
Hostetter, N.J.; Evans, A.F.; Roby, D.D.; Collis, K.; Hawbecker, M.; Sandford, B.P.; Thompson, D.E.; Loge, F.J.
Understanding how the external condition of juvenile salmonids is associated with internal measures of health and subsequent out-migration survival can be valuable for population monitoring programs. This study investigated the use of a rapid, nonlethal, external examination to assess the condition of run-of-the-river juvenile steelhead Oncorhynchus mykiss migrating from the Snake River to the Pacific Ocean. We compared the external condition (e.g., body injuries, descaling, external signs of disease, fin damage, and ectoparasite infestations) with (1) the internal condition of a steelhead as measured by the presence of selected pathogens detected by histopathology and polymerase chain reaction analysis and (2) out-migration survival through the Snake and Columbia rivers as determined by passive integrated transponder (PIT) tag technology. The results from steelhead captured and euthanized (n = 222) at Lower Monumental Dam on the lower Snake River in 2008 indicated that external condition was significantly correlated with selected measures of internal condition. The odds of testing positive for a pathogen were 39.2, 24.3, and 5.6 times greater for steelhead with severe or moderate external signs of disease or more than 20% descaling, respectively. Capture-recapture models of 22,451 PIT-tagged steelhead released at Lower Monumental Dam in 2007-2009 indicated that external condition was significantly correlated with juvenile survival. The odds of outmigration survival for steelhead with moderate or severe external signs of disease, more than 20% descaling, or severe fin damage were 5.7, 4.9, 1.6, and 1.3 times lower, respectively, than those for steelhead without these external conditions. This study effectively demonstrated that specific measures of external condition were associated with both the internal condition and out-migration survival of juvenile steelhead. ?? American Fisheries Society 2011.
Aliouat-Denis, Cécile-Marie; Chabé, Magali; Delhaes, Laurence; Dei-Cas, Eduardo
In the last few decades, aerially transmitted human fungal pathogens have been increasingly recognized to impact the clinical course of chronic pulmonary diseases, such as asthma, cystic fibrosis or chronic obstructive pulmonary disease. Thanks to recent development of culture-free high-throughput sequencing methods, the metagenomic approaches are now appropriate to detect, identify and even quantify prokaryotic or eukaryotic microorganism communities inhabiting human respiratory tract and to access the complexity of even low-burden microbe communities that are likely to play a role in chronic pulmonary diseases. In this review, we explore how metagenomics and comparative genomics studies can alleviate fungal culture bottlenecks, improve our knowledge about fungal biology, lift the veil on cross-talks between host lung and fungal microbiota, and gain insights into the pathogenic impact of these aerially transmitted fungi that affect human beings. We reviewed metagenomic studies and comparative genomic analyses of carefully chosen microorganisms, and confirmed the usefulness of such approaches to better delineate biology and pathogenesis of aerially transmitted human fungal pathogens. Efforts to generate and efficiently analyze the enormous amount of data produced by such novel approaches have to be pursued, and will potentially provide the patients suffering from chronic pulmonary diseases with a better management. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.
Full Text Available In view of recent understanding of the association of periodontal infections and adverse pregnancy outcomes, the present investigation was undertaken to study the periodontal infections among 390 asymptomatic pregnant women and to find an association of bacterial etiologies with the disease. Prevalence of gingivitis was 38% and clinical periodontitis was 10% among the study population. Subgingival plaque specimens were subjected to multiplex PCR targeting ten putative periodontopathogenic bacteria. Among the periodontitis group, high detection rates of Porphyromonas gingivalis (56%, Prevotella nigrescens (44%, Treponema denticola (32%, and Prevotella intermedius (24% were noted along with significant association with the disease (P<0.05.
Srinivasan S, Madhusudhan NS
Full Text Available Urinary tract infection (UTI is one of the commonest medical problems in children. It can distress the child and may cause kidney damage. Prompt diagnosis and effective treatment can prevent complications in the child. But treatment of UTI in children has now become a challenge due to the emergence of multidrug resistant bacteria. Aims & Objectives: To know the bacteriological profile and susceptibility pattern of urinary tract infections in children and to know the prevalence of multidrug resistant uropathogens. Materials & Methods: A retrospective analysis was done on all paediatric urine samples for a period of one year. A total of 1581 samples were included in the study. Antimicrobial susceptibility testing was done on samples showing significant growth by Kirby-Bauer disc diffusion method. Statistical analysis: Prevalence and pattern were analyzed using proportions and percentages. Results: E.coli was the most predominant organism (56% causing UTI in children followed by Klebsiella sp (17%. Fifty three percent of gram negative organisms isolated from children were found to be multidrug resistant. Majority of E. coli isolates were found to be highly resistant to Ampicillin (91% and Cotrimoxazole (82% and highly sensitive to Imipenem (99% and Amikacin (93%. Conclusion: Paediatric UTI was common in children less than 5 years of age. Gram negative bacteria (E. coli and Klebsiella sp were more common than gram positive bacteria. Our study revealed that multidrug resistance was higher in E.coli.
Tabachnick, Walter J
Arthropod-borne pathogens have an impact on the health and well-being of humans and animals throughout the world. Research involving arthropod vectors of disease is often dependent on the ability to maintain the specific arthropod species in laboratory colonies. The author reviews current arthropod containment practices and discusses their importance from public health and ecological perspectives.
Triana, Sergio; González, Andrés; Ohm, Robin A.; Wösten, Han A. B.; de Cock, Hans; Restrepo, Silvia
Malassezia pachydermatis is a basidiomycetous yeast that causes infections in humans and animals. Here, we report the genome sequence of Malassezia pachydermatis strain CBS 1879, which will facilitate the study of mechanisms underlying pathogenicity of the only non-lipid-dependent Malasezzia species. PMID:26472839
Full Text Available Pathogen host shifts represent a major source of new infectious diseases. There are several examples of cross-genus host jumps that have caused catastrophic epidemics in animal and plant species worldwide. Cross-kingdom jumps are rare, and are often associated with nosocomial infections. Here we provide an example of human-mediated cross-kingdom jumping of Exserohilum rostratum isolated from a patient who had received a corticosteroid injection and died of fungal meningitis in a Florida hospital in 2012. The clinical isolate of E. rostratum was compared with two plant pathogenic isolates of E. rostratum and an isolate of the closely related genus Bipolaris in terms of morphology, phylogeny, and pathogenicity on one C3 grass, Gulf annual rye grass (Lolium multiflorum, and two C4 grasses, Japanese stilt grass (Microstegium vimineum and bahia grass (Paspalum notatum. Colony growth and color, as well as conidia shape and size were the same for the clinical and plant isolates of E. rostratum, while these characteristics differed slightly for the Bipolaris sp. isolate. The plant pathogenic and clinical isolates of E. rostratum were indistinguishable based on morphology and ITS and 28S rDNA sequence analysis. The clinical isolate was as pathogenic to all grass species tested as the plant pathogenic strains that were originally isolated from plant hosts. The clinical isolate induced more severe symptoms on stilt grass than on rye grass, while this was the reverse for the plant isolates of E. rostratum. The phylogenetic similarity between the clinical and plant-associated E. rostratum isolates and the ability of the clinical isolate to infect plants suggests that a plant pathogenic strain of E. rostratum contaminated the corticosteroid injection fluid and was able to cause systemic disease in the affected patient. This is the first proof that a clinical isolate of E. rostratum is also an effective plant pathogen.
Davies, Saran; Abdullah, Swaid; Helps, Chris; Tasker, Séverine; Newbury, Hannah; Wall, Richard
In a study of tick and tick-borne pathogen prevalence, between May and October 2016, 278 veterinary practices in Great Britain examined 1855 cats. Six-hundred and one cats were found to have attached ticks. The most frequently recorded tick species was Ixodes ricinus (57.1%), followed by Ixodes hexagonus (41.4%) and Ixodes trianguliceps (1.5%). Male cats, 4-6 years of age living in rural areas were most likely to be carrying a tick; hair length and tick treatment history had no significant association with attachment. For cats that were parasitized by ticks in large urban areas, I. hexagonus was the most frequent species recorded. Molecular analysis was possible for 541 individual tick samples, others were too damaged for analysis; Babesia spp., and Borrelia burgdorferi sensu lato were identified in 1.1% (n=6) and 1.8% (n=10) of these, respectively. Babesia spp. included Babesia vulpes sp. nov./Babesia microti-like (n=4) in I. hexagonus and Babesia venatorum (n=2) in I. ricinus. Borrelia burgdorferi s.l. species included Borrelia garinii (n=6) and Borrelia afzelii (n=4). The majority of B. burgorferi s.l. cases were found in I. ricinus, with B. afzelii in one I. hexagonus nymph. No Borrelia or Babesia spp. were present in I. trianguliceps. To determine a true prevalence for ticks on cats, practices that only submitted questionnaires from cats with ticks and practices that submitted fewer than 5 returns per week were removed; amongst those considered to have adhered strictly to the collection protocol, feline tick prevalence amongst cats that had access to the outdoors was 6.6%. These results show that ticks can be found on cats throughout Great Britain, which harbour a range of species of Babesia and B. burgdorferi s.l. and that cats, particularly in green spaces within urban areas, may form an important host for I. hexagonus, a known vector of pathogens. Copyright © 2017 Elsevier B.V. All rights reserved.
Carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) are exploited by human-specific pathogens to anchor themselves to or invade host cells. Interestingly, human granulocytes express a specific isoform, CEACAM3, that can direct efficient, opsonin-independent phagocytosis of CEACAM-binding Neisseria, Moraxella and Haemophilus species. As opsonin-independent phagocytosis of CEACAM-binding Neisseria depends on Src-family protein tyrosine kinase (PTK) phosphorylation of the CEACAM3 ...
Sarah L James
Full Text Available Scrub typhus is a common cause of undiagnosed febrile illness in certain tropical regions, but can be easily treated with antibiotics. The causative agent, Orientia tsutsugamushi, is antigenically variable which complicates diagnosis and efforts towards vaccine development.This study aimed to dissect the antigenic and genetic relatedness of O. tsutsugamushi strains and investigate sero-diagnostic reactivities by titrating individual patient sera against their O. tsutsugamushi isolates (whole-cell antigen preparation, in homologous and heterologous serum-isolate pairs from the same endemic region in NE Thailand. The indirect immunofluorescence assay was used to titrate Orientia tsutsugamushi isolates and human sera, and a mathematical technique, antigenic cartography, was applied to these data to visualise the antigenic differences and cross-reactivity between strains and sera. No functional or antigen-specific analyses were performed. The antigenic variation found in clinical isolates was much less pronounced than the genetic differences found in the 56kDa type-specific antigen genes. The Karp-like sera were more broadly reactive than the Gilliam-like sera.Antigenic cartography worked well with scrub typhus indirect immunofluorescence titres. The data from humoral responses suggest that a Karp-like strain would provide broader antibody cross-reactivity than a Gilliam-like strain. Although previous exposure to O. tsutsugamushi could not be ruled out, scrub typhus patient serum antibody responses were characterised by strong homologous, but weak heterologous antibody titres, with little evidence for cross-reactivity by Gilliam-like sera, but a broader response from some Karp-like sera. This work highlights the importance of antigenic variation in O. tsutsugamushi diagnosis and determination of new serotypes.
Hussain, T.; Ishtiaq, M.; Hussain, A.; Sultana, K.
Pathogenic fungi of drinking water have potentially prevailing effects on human beings. Myco floral study of drinking water of district Bhimber, Azad Kashmir was conducted through systematic sampling and temporally during the year 2009. Drinking water samples were collected from selected spots and fungal spores were grown on two different culture media viz: potato dextrose agar (PDA) and nutrient agar (NA) and identified by employing Direct Plate method (DPM) and Baiting Technique (BT). A total of 4 resources of drinking water of the area were analyzed i.e., well, spring, hand pump and tap water (water supply system). Sixteen different fungal species were frequently prevailing in the analyzed samples and among these five species were predominantly found human pathogenic. The density of identified fungal species in well's water samples (WWS) was 11 spp. spring's water samples (SWS) 6 spp. hand pump water samples (HWS) 8 spp. and tap water samples (TWS) 7 spp. This differential incidence in the samples might be due to variation in geography, edaphalogy, altitude, temperature, in fungal growth substrate variance and analytical difference of sampling and analysis methods. The prevalence values of mycolfora in different samples were variable with WWS Mucor fragilis (18a - LSD), SWS Brevilegnia sp. (20a - LSD), HWS Aspergillus flavus (14a- LSD) and TWS Alternaria alternata (12a - LSD). It was noted that WWS more frequently depicted mycoflora because land/well provides best environment and nourishment for growth and reproduction of fungi. The economic importance and pathogenic toxicity of various species is also measured and documented in the article. (author)
Heimersson, Sara; Harder, Robin; Peters, Gregory M; Svanström, Magdalena
Resource recovery from sewage sludge has the potential to save natural resources, but the potential risks connected to human exposure to heavy metals, organic micropollutants, and pathogenic microorganisms attract stakeholder concern. The purpose of the presented study was to include pathogen risks to human health in life cycle assessment (LCA) of wastewater and sludge management systems, as this is commonly omitted from LCAs due to methodological limitations. Part 1 of this article series estimated the overall pathogen risk for such a system with agricultural use of the sludge, in a way that enables the results to be integrated in LCA. This article (part 2) presents a full LCA for two model systems (with agricultural utilization or incineration of sludge) to reveal the relative importance of pathogen risk in relation to other potential impacts on human health. The study showed that, for both model systems, pathogen risk can constitute an important part (in this study up to 20%) of the total life cycle impacts on human health (expressed in disability adjusted life years) which include other important impacts such as human toxicity potential, global warming potential, and photochemical oxidant formation potential.
Zadoks, Ruth N; Middleton, John R; McDougall, Scott; Katholm, Jorgen; Schukken, Ynte H
Mastitis, inflammation of the mammary gland, can be caused by a wide range of organisms, including gram-negative and gram-positive bacteria, mycoplasmas and algae. Many microbial species that are common causes of bovine mastitis, such as Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae and Staphylococcus aureus also occur as commensals or pathogens of humans whereas other causative species, such as Streptococcus uberis, Streptococcus dysgalactiae subsp. dysgalactiae or Staphylococcus chromogenes, are almost exclusively found in animals. A wide range of molecular typing methods have been used in the past two decades to investigate the epidemiology of bovine mastitis at the subspecies level. These include comparative typing methods that are based on electrophoretic banding patterns, library typing methods that are based on the sequence of selected genes, virulence gene arrays and whole genome sequencing projects. The strain distribution of mastitis pathogens has been investigated within individual animals and across animals, herds, countries and host species, with consideration of the mammary gland, other animal or human body sites, and environmental sources. Molecular epidemiological studies have contributed considerably to our understanding of sources, transmission routes, and prognosis for many bovine mastitis pathogens and to our understanding of mechanisms of host-adaptation and disease causation. In this review, we summarize knowledge gleaned from two decades of molecular epidemiological studies of mastitis pathogens in dairy cattle and discuss aspects of comparative relevance to human medicine.
Full Text Available Beneficial effects of breastfeeding are well-recognized and include both immediate neonatal protection against pathogens, as well as long term protection against allergies and autoimmune diseases. Although several proteins have been identified to have anti-viral or anti-bacterial effects like secretory IgA or lactoferrin, the mechanisms of immune modulation are not fully understood. Recent studies identified important beneficial effects of glycans in human milk, such as those expressed in oligosaccharides or on glycoproteins. Glycans are recognized by the carbohydrate receptors C-type lectins on DC and specific tissue macrophages, which exert important functions in immune modulation and immune homeostasis. A well-characterized C-type lectin is DC-SIGN, which binds terminal fucose. The present study shows that in human milk, MUC1 is the major milk glycoprotein that binds to the lectin domain of DC-SIGN and prevents pathogen interaction through the presence of Lewis x-type oligosaccharides. Surprisingly, this was specific for human milk, as formula, bovine or camel milk did not show any presence of proteins that interacted with DC-SIGN. The expression of DC-SIGN is found in young infants along the entire gastro-intestinal tract. Our data thus suggest the importance of human milk glycoproteins for blocking pathogen interaction to DC in young children. Moreover, a potential benefit of human milk later in life in shaping the infants immune system through DC-SIGN cannot be ruled out.
Jonah Piovia-Scott; Karen L. Pope; Sharon P. Lawler; Esther M. Cole; Janet E. Foley
The fungal pathogen Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis, has been associated with declines and extinctions of montane amphibians worldwide. To gain insight into factors affecting its distribution and prevalence we focus on the amphibian community of the Klamath Mountains in northwest...
Conclusion: Although E. coli remains the prime pathogen in pediatric UTI, the prevalence of resistance has dramatically increased over the 5-year study period. Our study highlights the emergence of community-acquired ESBL-producing uropathogens in children proclaiming treatment challenges.
Full Text Available Abstract Background For decades, scientists have tried to understand the environmental factors involved in the development of systemic lupus erythematosus (SLE, in which viral infections was included. Previous studies have identified Epstein-Barr virus (EBV to incite SLE. Human herpesvirus 8 (HHV-8, another member of the gammaherpesvirus family, shares a lot in common with EBV. The characteristics of HHV-8 make it a well-suited candidate to trigger SLE. Results In the present study, serum samples from patients (n = 108 with diagnosed SLE and matched controls (n = 122 were collected, and the prevalence of HHV-8 was compared by a virus-specific nested PCR and a whole virus enzyme-linked immunoassay (EIA. There was significant difference in the prevalence of HHV-8 DNA between SLE patients and healthy controls (11 of 107 vs 1 of 122, p = 0.001; significant difference was also found in the detection of HHV-8 antibodies (19 of 107 vs 2 of 122, p We also detected the antibodies to Epstein-Barr virus viral capsid antigen (EBV-VCA and Epstein-Barr nuclear antigen-1 (EBNA-1. Both patients and controls showed high seroprevalence with no significant difference (106 of 107 vs 119 of 122, p = 0.625. Conclusion Our finding indicated that there might be an association between HHV-8 and the development of SLE.
Fluctuations of metabolic reaction fluxes may cause abnormal concentrations of toxic or essential metabolites, possibly leading to metabolic diseases. The mutual binding of enzymatic proteins and ones involving common metabolites enforces distinct coupled reactions, by which local perturbations may spread through the cellular network. Such network effects at the molecular interaction level in human cellular metabolism can reappear in the patterns of disease occurrence. Here we construct the enzyme-reaction network and the metabolite-reaction network, capturing the flux coupling of metabolic reactions caused by the interacting enzymes and the shared metabolites, respectively. Diseases potentially caused by the failure of individual metabolic reactions can be identified by using the known disease–gene association, which allows us to derive the probability of an inactivated reaction causing diseases from the disease records at the population level. We find that the greater the number of proteins that catalyze a reaction, the higher the mean prevalence of its associated diseases. Moreover, the number of connected reactions and the mean size of the avalanches in the networks constructed are also shown to be positively correlated with the disease prevalence. These findings illuminate the impact of the cellular network topology on disease development, suggesting that the global organization of the molecular interaction network should be understood to assist in disease diagnosis, treatment, and drug discovery
Fluctuations of metabolic reaction fluxes may cause abnormal concentrations of toxic or essential metabolites, possibly leading to metabolic diseases. The mutual binding of enzymatic proteins and ones involving common metabolites enforces distinct coupled reactions, by which local perturbations may spread through the cellular network. Such network effects at the molecular interaction level in human cellular metabolism can reappear in the patterns of disease occurrence. Here we construct the enzyme-reaction network and the metabolite-reaction network, capturing the flux coupling of metabolic reactions caused by the interacting enzymes and the shared metabolites, respectively. Diseases potentially caused by the failure of individual metabolic reactions can be identified by using the known disease-gene association, which allows us to derive the probability of an inactivated reaction causing diseases from the disease records at the population level. We find that the greater the number of proteins that catalyze a reaction, the higher the mean prevalence of its associated diseases. Moreover, the number of connected reactions and the mean size of the avalanches in the networks constructed are also shown to be positively correlated with the disease prevalence. These findings illuminate the impact of the cellular network topology on disease development, suggesting that the global organization of the molecular interaction network should be understood to assist in disease diagnosis, treatment, and drug discovery.
Full Text Available Pathogenicity of the human pathogen Helicobacter pylori relies upon its capacity to adapt to a hostile environment and to escape from the host response. Therefore, cell shape, motility, and pH homeostasis of these bacteria are specifically adapted to the gastric mucus. We have found that the helical shape of H. pylori depends on coiled coil rich proteins (Ccrp, which form extended filamentous structures in vitro and in vivo, and are differentially required for the maintenance of cell morphology. We have developed an in vivo localization system for this pathogen. Consistent with a cytoskeleton-like structure, Ccrp proteins localized in a regular punctuate and static pattern within H. pylori cells. Ccrp genes show a high degree of sequence variation, which could be the reason for the morphological diversity between H. pylori strains. In contrast to other bacteria, the actin-like MreB protein is dispensable for viability in H. pylori, and does not affect cell shape, but cell length and chromosome segregation. In addition, mreB mutant cells displayed significantly reduced urease activity, and thus compromise a major pathogenicity factor of H. pylori. Our findings reveal that Ccrp proteins, but not MreB, affect cell morphology, while both cytoskeletal components affect the development of pathogenicity factors and/or cell cycle progression.
Nsoh, Fuh Anold; Wung, Buh Amos; Atashili, Julius; Benjamin, Pokam Thumamo; Marvlyn, Eba; Ivo, Keumami Katte; Nguedia, Assob Jules Clément
Access to potable water remains a major challenge particularly in resource-limited settings. Although the potential contaminants of water are varied, enteric pathogenic protozoa are known to cause waterborne diseases greatly. This study aimed at investigating the prevalence, characteristics and correlates of enteric pathogenic protozoa in drinking water sources in Buea, Cameroon. A cross-sectional study was conducted using 155 water samples collected from various drinking sources (boreholes, springs, taps and wells). Each sample was subjected to physicochemical examinations (pH, turbidity, odour and sliminess) and parasitological analysis (wet mount, modified Ziehl-Neelsen stain) to determine the presence of enteric pathogenic protozoa. A data collection tool was used to note characteristics of collected samples and the data was analysed using EPI-INFO Version 3.5.3. The overall prevalence of enteric pathogenic protozoa in water sources was 62.6 %. Eight species of enteric protozoa were observed with Cryptosporidium parvum being the most predominant (45.8 %). Spring water was the most contaminated source with enteric protozoa (85.7 %) while pipe borne water had all eight species of protozoa identified. A pH of 6 was the only significant factor associated with the prevalence of these pathogens in water sources. The prevalence of enteric protozoa in water sources in Molyko and Bomaka is high, spring water is the most contaminated water source and Cryptosporidium parvum is the most common protozoa contaminating water. A water pH of 6 is associated to the prevalence of protozoa. Community members need to be educated to treat water before drinking to avoid infection by enteric protozoa in water and further studies with larger samples of water need to be conducted to find other correlates of the presence of protozoa in water.
Full Text Available Previous genome-wide scans of positive natural selection in humans have identified a number of non-neutrally evolving genes that play important roles in skin pigmentation, metabolism, or immune function. Recent studies have also shown that a genome-wide pattern of local adaptation can be detected by identifying correlations between patterns of allele frequencies and environmental variables. Despite these observations, the degree to which natural selection is primarily driven by adaptation to local environments, and the role of pathogens or other ecological factors as selective agents, is still under debate. To address this issue, we correlated the spatial allele frequency distribution of a large sample of SNPs from 55 distinct human populations to a set of environmental factors that describe local geographical features such as climate, diet regimes, and pathogen loads. In concordance with previous studies, we detected a significant enrichment of genic SNPs, and particularly non-synonymous SNPs associated with local adaptation. Furthermore, we show that the diversity of the local pathogenic environment is the predominant driver of local adaptation, and that climate, at least as measured here, only plays a relatively minor role. While background demography by far makes the strongest contribution in explaining the genetic variance among populations, we detected about 100 genes which show an unexpectedly strong correlation between allele frequencies and pathogenic environment, after correcting for demography. Conversely, for diet regimes and climatic conditions, no genes show a similar correlation between the environmental factor and allele frequencies. This result is validated using low-coverage sequencing data for multiple populations. Among the loci targeted by pathogen-driven selection, we found an enrichment of genes associated to autoimmune diseases, such as celiac disease, type 1 diabetes, and multiples sclerosis, which lends credence to the
de Rochefort Anna
Full Text Available Abstract Background New and improved antimicrobial countermeasures are urgently needed to counteract increased resistance to existing antimicrobial treatments and to combat currently untreatable or new emerging infectious diseases. We demonstrate that computational comparative genomics, together with experimental screening, can identify potential generic (i.e., conserved across multiple pathogen species and novel virulence-associated genes that may serve as targets for broad-spectrum countermeasures. Results Using phylogenetic profiles of protein clusters from completed microbial genome sequences, we identified seventeen protein candidates that are common to diverse human pathogens and absent or uncommon in non-pathogens. Mutants of 13 of these candidates were successfully generated in Yersinia pseudotuberculosis and the potential role of the proteins in virulence was assayed in an animal model. Six candidate proteins are suggested to be involved in the virulence of Y. pseudotuberculosis, none of which have previously been implicated in the virulence of Y. pseudotuberculosis and three have no record of involvement in the virulence of any bacteria. Conclusion This work demonstrates a strategy for the identification of potential virulence factors that are conserved across a number of human pathogenic bacterial species, confirming the usefulness of this tool.
Riehm, Julia M; Löscher, Thomas
Yersinia pestis is a highly pathogenic gram-negative bacterium and the causative agent of human plague. In the last 1500 years and during three dreaded pandemics, millions of people became victims of Justinian's plague, the Black Death, or modern plague. Today, Y. pestis is endemic in natural foci of Asian, African and American countries. Due to its broad dissemination in mammal species and fleas, eradication of the pathogen will not be possible in the near future. In fact, plague is currently classified as a "re-emerging disease". Infection may occur after the bite of an infected flea, but also after oral ingestion or inhalation of the pathogen. The clinical presentations comprise the bubonic and pneumonic form, septicemia, rarely pharyngitis, and meningitis. Most human cases can successfully be treated with antibiotics. However, the high transmission rate and lethality of pneumonic plague require international and mandatory case notification and quarantine of patients. Rapid diagnosis, therapy and barrier nursing are not only crucial for the individual patient but also for the prevention of further spread of the pathogen or of epidemics. Therefore, WHO emergency schedules demand the isolation of cases, identification and surveillance of contacts as well as control of zoonotic reservoir animals and vectors. These sanctions and effective antibiotic treatment usually allow a rapid containment of outbreaks. However, multiple antibiotic resistant strains of Y. pestis have been isolated from patients in the past. So far, no outbreaks with such strains have been reported.
Menon, S.; Timms, P.; Allan, J. A.; Alexander, K.; Rombauts, L.; Horner, P.; Keltz, M.; Hocking, J.
SUMMARY Chlamydia trachomatis is the most common bacterial sexually transmitted pathogen worldwide. Infection can result in serious reproductive pathologies, including pelvic inflammatory disease, ectopic pregnancy, and infertility, in women. However, the processes that result in these reproductive pathologies have not been well defined. Here we review the evidence for the human disease burden of these chlamydial reproductive pathologies. We then review human-based evidence that links Chlamydia with reproductive pathologies in women. We present data supporting the idea that host, immunological, epidemiological, and pathogen factors may all contribute to the development of infertility. Specifically, we review the existing evidence that host and pathogen genotypes, host hormone status, age of sexual debut, sexual behavior, coinfections, and repeat infections are all likely to be contributory factors in development of infertility. Pathogen factors such as infectious burden, treatment failure, and tissue tropisms or ascension capacity are also potential contributory factors. We present four possible processes of pathology development and how these processes are supported by the published data. We highlight the limitations of the evidence and propose future studies that could improve our understanding of how chlamydial infertility in women occurs and possible future interventions to reduce this disease burden. PMID:26310245
Matthew T G Holden
Full Text Available The continued evolution of bacterial pathogens has major implications for both human and animal disease, but the exchange of genetic material between host-restricted pathogens is rarely considered. Streptococcus equi subspecies equi (S. equi is a host-restricted pathogen of horses that has evolved from the zoonotic pathogen Streptococcus equi subspecies zooepidemicus (S. zooepidemicus. These pathogens share approximately 80% genome sequence identity with the important human pathogen Streptococcus pyogenes. We sequenced and compared the genomes of S. equi 4047 and S. zooepidemicus H70 and screened S. equi and S. zooepidemicus strains from around the world to uncover evidence of the genetic events that have shaped the evolution of the S. equi genome and led to its emergence as a host-restricted pathogen. Our analysis provides evidence of functional loss due to mutation and deletion, coupled with pathogenic specialization through the acquisition of bacteriophage encoding a phospholipase A(2 toxin, and four superantigens, and an integrative conjugative element carrying a novel iron acquisition system with similarity to the high pathogenicity island of Yersinia pestis. We also highlight that S. equi, S. zooepidemicus, and S. pyogenes share a common phage pool that enhances cross-species pathogen evolution. We conclude that the complex interplay of functional loss, pathogenic specialization, and genetic exchange between S. equi, S. zooepidemicus, and S. pyogenes continues to influence the evolution of these important streptococci.
Bienek, A; Heisz, M; Su, M
Canada recently enacted legislation to authorize the collection of data on laboratory incidents involving a biological agent. This is done by the Public Health Agency of Canada (PHAC) as part of a comprehensive national program that protects Canadians from the health and safety risks posed by human and terrestrial animal pathogens and toxins. To describe the first year of data on laboratory exposure incidents and/or laboratory-acquired infections in Canada since the Human Pathogens and Toxins Regulations came into effect. Incidents that occurred between January 1 and December 31, 2016 were self-reported by federally-regulated parties across Canada using a standardized form from the Laboratory Incident Notification Canada (LINC) surveillance system. Exposure incidents were described by sector, frequency of occurrence, timeliness of reporting, number of affected persons, human pathogens and toxins involved, causes and corrective actions taken. Microsoft Excel 2010 was used for basic descriptive analyses. In 2016, 46 exposure incidents were reported by holders of 835 active licences in Canada representing 1,352 physical areas approved for work involving a biological agent, for an overall incidence of 3.4%. The number of incidents was highest in the academic (n=16; 34.8%) and hospital (n=12; 26.1%) sectors, while the number of reported incidents was relatively low in the private industry sector. An average of four to five incidents occurred each month; the month of September presented as an outlier with 10 incidents. : A total of 100 people were exposed, with no reports of secondary exposure. Four incidents led to suspected (n=3) or confirmed (n=1) cases of laboratory-acquired infection. Most incidents involved pathogens classified at a risk group 2 level that were manipulated in a containment level 2 laboratory (91.3%). Over 22 different species of human pathogens and toxins were implicated, with bacteria the most frequent (34.8%), followed by viruses (26
Full Text Available Introduction: Mycoplasma bovis is one of the main pathogens involved in cattle pneumonia. Other mycoplasmas have also been directly implicated in respiratory diseases in cattle. The prevalence of different Mycoplasma spp. in cattle affected by respiratory diseases and molecular characteristics of M. bovis field strains were evaluated. Material and Methods: In total, 713 nasal swabs from 73 cattle herds were tested. The uvrC gene fragment was amplified by PCR and PCR products were sequenced. PCR/DGGE and RAPD were performed. Results: It was found that 39 (5.5% samples were positive for M. bovis in the PCR and six field strains had point nucleotide mutations. Additionally, the phylogenetic analysis of 20 M. bovis field strains tested with RAPD showed two distinct groups of M. bovis strains sharing only 3.8% similarity. PCR/DGGE analysis demonstrated the presence of bacteria belonging to the Mollicutes class in 79.1% of DNA isolates. The isolates were identified as: Mycoplasma bovirhinis, M. dispar, M. bovis, M. canis, M. arginini, M. canadense, M. bovoculi, M. alkalescens, and Ureaplasma diversum. Conclusion: Different Mycoplasma spp. strains play a crucial role in inducing respiratory diseases in cattle.
Zulkifli, Syahida Amani; Mohamad, Che Wan Syarifah Robiah; Abdullah, Abu Hassan
This paper present human pathogen bacteria for early screening using electronic nose. Electronic nose (E-nose) known as gas sensor array is a device that analyze the odor measurement give the fast response and less time consuming for clinical diagnosis. Many bacterial pathogens could lead to life threatening infections. Accurate and rapid diagnosis is crucial for the successful management of these infections disease. The conventional method need more time to detect the growth of bacterial. Alternatively, the bacteria are Pseudomonas aeruginosa and Shigella cultured on different media agar can be detected and classifies according to the volatile compound in shorter time using electronic nose (E-nose). Then, the data from electronic nose (E-nose) is processed using statistical method which is principal component analysis (PCA). The study shows the capability of electronic nose (E-nose) for early screening for bacterial infection in human stomach.
Nagvenkar, G.S.; Ramaiah, N.
contamination, allochthonous bacteria Introduction: Environmental surveys are necessary for understanding and documenting the occurrence and distribution of pollution indicator and human pathogenic bacteria. In order to quantify and understand... and Chandramohan 1993; Ruiz et al. 2000; Ramaiah and De 2003). Mortality and survival rates of fecal contamination indicator Escherichia coli in the marine regimes have also been studied (Thom et al. 1992; Darakas 2001). Findings from these studies affirm...
Eine Infektion durch das ausschließlich human-spezifische Pathogen Neisseria gonorrhoeae manifestiert sich bei einer symptomatischen Kolonisierung in der sog. Gonorrhö, einer venerischen Erkrankung, die durch akute Inflammation des befallenen Gewebes und durch die massive Infiltration von Granulozyten charakterisiert ist. Die Gonokokken können im Verlauf einer symptomatischen Infektion über ihre OpaCEA-Adhäsine mit CEACAM Proteinen unterschiedlicher Wirtszellen interagieren. In der vorliegend...
Mendoza-Olazar?n, Soraya; Garcia-Mazcorro, Jos? F.; Morf?n-Otero, Rayo; Villarreal-Trevi?o, Licet; Camacho-Ortiz, Adri?n; Rodr?guez-Noriega, Eduardo; Bocanegra-Ibarias, Paola; Maldonado-Garza, H?ctor J.; Dowd, Scot E.; Garza-Gonz?lez, Elvira
Herein, we report the draft-genome sequences and annotation of two opportunistic pathogenic strains of Staphylococcus cohnii isolated from humans. One strain (SC-57) was isolated from blood from a male patient in May 2006 and the other (SC-532) from a catheter from a male patient in June 2006. Similar to other genomes of Staphylococcus species, most genes (42%) of both strains are involved in metabolism of amino acids and derivatives, carbohydrates and proteins. Eighty (4%) genes are involved...
Ishii, Satoshi; Yan, Tao; Shively, Dawn A.; Byappanahalli, Muruleedhara N.; Whitman, Richard L.; Sadowsky, Michael J.
Cladophora glomerata, a macrophytic green alga, is commonly found in the Great Lakes, and significant accumulations occur along shorelines during the summer months. Recently, Cladophora has been shown to harbor high densities of the fecal indicator bacteria Escherichia coli and enterococci. Cladophora may also harbor human pathogens; however, until now, no studies to address this question have been performed. In the present study, we determined whether attached Cladophora, obtained from the L...
Loftus, Brendan J.; Fung, Eula; Roncaglia, Paola; Rowley, Don; Amedeo, Paolo; Bruno, Dan; Vamathevan, Jessica; Miranda, Molly; Anderson, Iain J.; Fraser, James A.; Allen, Jonathan E.; Bosdet, Ian E.; Brent, Michael R.; Chiu, Readman; Doering, Tamara L.
Cryptococcus neoformans is a basidiomycetous yeast ubiquitous in the environment, a model for fungal pathogenesis, and an opportunistic human pathogen of global importance. We have sequenced its ~20-megabase genome, which contains ~6500 intron-rich gene structures and encodes a transcriptome abundant in alternatively spliced and antisense messages. The genome is rich in transposons, many of which cluster at candidate centromeric regions. The presence of these transposons may drive karyotype i...
Hasan, Mohammad R.; Rawat, Arun; Tang, Patrick; Jithesh, Puthen V.; Thomas, Eva; Tan, Rusung; Tilley, Peter
Next-generation sequencing (NGS) technology has shown promise for the detection of human pathogens from clinical samples. However, one of the major obstacles to the use of NGS in diagnostic microbiology is the low ratio of pathogen DNA to human DNA in most clinical specimens. In this study, we aimed to develop a specimen-processing protocol to remove human DNA and enrich specimens for bacterial and viral DNA for shotgun metagenomic sequencing. Cerebrospinal fluid (CSF) and nasopharyngeal aspi...
Rusan, M; Klug, T E; Henriksen, J J; Bonde, J H; Fuursted, K; Ovesen, T
The incidence of tonsillar carcinomas associated with Human Papillomavirus (HPV) infection has increased dramatically over the last three decades. In fact, currently in Scandinavia, HPV-associated cases account for over 80 % of tonsillar carcinoma cases. Yet, the epidemiology and natural history of tonsillar HPV infections remains poorly characterized. Our aim was to characterize such infections in the Danish population in tumor-free tonsillar tissue. Unlike previous studies, we considered both palatine tonsils. We examined both tonsils from 80 patients with peritonsillar abscess (n = 25) or chronic tonsillar disease (n = 55). HPV was detected by nested PCR with PGMY 09/11 and GP5+/GP6+L1 consensus primers, and typed by sequencing. Samples were also analyzed using a higher-throughput method, the CLART HPV 2 Clinical Array Assay. The overall prevalence of HPV tonsillar infection was 1.25 % (1/80, 95 % CI 0.03-6.77 %) by nested PCR, and 0 % by CLART HPV2 Clinical Array. The HPV-positive patient was a 16-year-old female with recurrent tonsillitis and tonsillar hypertrophy. The type detected was HPV6. HPV was not detected in the contralateral tonsil of this patient. Compared to cervical HPV infections in Denmark, tonsillar HPV infections are 10- to 15-fold less frequent. In the HPV-positive patient in this study, HPV was detected in only one of the tonsils. This raises the possibility that prior studies may underestimate the prevalence of HPV infections, as they do not consider both palatine tonsils.
Full Text Available In recent years, increasing numbers of outbreaks caused by the consumption of vegetables contaminated with human pathogenic bacteria were reported. The application of organic fertilizers during vegetable production is one of the possible reasons for contamination with those pathogens. In this study laboratory experiments in axenic and soil systems following common practices in organic farming were conducted to identify the minimal dose needed for bacterial colonization of plants and to identify possible factors like bacterial species or serovariation, plant species or organic fertilizer types used, influencing the success of plant colonization by human pathogenic bacteria. Spinach and corn salad were chosen as model plants and were inoculated with different concentrations of Salmonella enterica sv. Weltevreden, Listeria monocytogenes sv. 4b and EGD-E sv. 1/2a either directly (axenic system or via agricultural soil amended with spiked organic fertilizers (soil system. In addition to PCR- and culture-based detection methods, fluorescence in situ hybridization (FISH was applied in order to localize bacteria on or in plant tissues. Our results demonstrate that shoots were colonized by the pathogenic bacteria at inoculation doses as low as 4x10CFU/ml in the axenic system or 4x105CFU/g in the soil system. In addition, plant species dependent effects were observed. Spinach was colonized more often and at lower inoculation doses compared to corn salad. Differential colonization sites on roots, depending on the plant species could be detected using FISH-CLSM analysis. Furthermore, the transfer of pathogenic bacteria to plants via organic fertilizers was observed more often and at lower initial inoculation doses when fertilization was performed with inoculated slurry compared to inoculated manure. Finally, it could be shown that by introducing a simple washing step, the bacterial contamination was reduced in most cases or even was removed completely in
Oyetunde T. Oyeyemi
Full Text Available Cockroaches and houseflies pose significant public health threat owning to their ability to mechanically transmit human intestinal parasites and other disease-causing microorganisms. This study aims at assessing the vectoral capacity of cockroaches and houseflies in the transmission of human intestinal parasites. Intestinal parasite external surface contamination of 130 cockroaches and 150 houseflies caught within dwelling places in Ilishan-Remo town, Ogun State, Nigeria was determined. Cockroaches (six parasite species were more contaminated than houseflies (four parasite species. The most prevalent parasites were Trichuris trichiura (74.0% and hookworm (63.0% in houseflies and cockroaches respectively. There were significant differences in the prevalence of hookworm, T. trichiura and Taenia spp. isolated from cockroaches and houseflies (P < 0.05. There is high contamination of human intestinal parasites in cockroaches and houseflies in human dwelling places in the study area, thus they have the ability to transmit these parasites to unkempt food materials.
Chicago Il, USA). Results: Overall HPV prevalence was 65.2% (277/425), with 85.9% (238/277) single and 14.1% (39/277) multiple infection. The most prevalent HPV types were HPVs 16, 58, 18, 31, and 45. HPV 16 was the most prevalent ...
Barnes, T; Holzrichter, J F; Milanovich, F P
contained in pathogen systems, such as their full genomic information, can be very helpful in identifying malevolent users. In addition, it is undoubtedly true that an understanding of replication and human or other sensitivity to pathogens will improve our medical understanding of human health in general
Full Text Available This study was conducted to evaluate the effect of aqueous, ethanolic and ethyl acetate extracts from neem leaves on growth of some human pathogens (Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus terreus, Candida albicans and Microsporum gypseum in vitro. Different concentrations (5, 10, 15 and 20% prepared from these extracts inhibited the growth of the test pathogens and the effect gradually increased with concentration. The 20% ethyl acetate extract gave the strongest inhibition compared with the activity obtained by the same concentration of the other extracts. High Performance Liquid Chromatography (HPLC analysis of ethyl acetate extract showed the presence of a main component (nimonol which was purified and chemically confirmed by Nuclear Magnetic Resonance (NMR spectroscopic analysis. The 20% ethyl acetate extract lost a part of its antifungal effect after pooling out the nimonol and this loss in activity was variable on test pathogens. The purified nimonol as a separate compound did not show any antifungal activity when assayed against all the six fungal pathogens.
El-Semary, N.A.; Osman, M.E.; Ahmed, A.S.; Botros, H.W.; Farag, A.T.
The search for broad spectrum antimicrobial agents against microbial pathogens, as the available bioactive compounds, has decreasing efficacy and the multidrug resistance trait is spreading among pathogens. Accordingly, the study was carried out to investigate the antimicrobial bioactivity of extracts derived from a cyano bacterial strain from Egypt. The solvents used were diethyl ether, chloroform and methanol. The antimicrobial bioassay of the lipophilic fraction dissolved in diethyl ether of Synechococcus spp. (isolated from Wadi El-Natroun, Egypt) showed the highest broad spectrum bioactivity as it inhibited the growth of both plant and human pathogens. The extract was also effective on the filamentous plant pathogenic fungi Aspergillus flavus and Aspergillus niger. The effects of incubation periods, growth media and pH values on both growth and antimicrobial activity of Synechococcus spp. were investigated. Chu medium was the medium that gave the highest growth followed by BG11 medium then Oscillatoria medium and all these three media showed antibacterial activities but only BG11 showed both antibacterial and antifungal activities after 18 days of incubation. The pH value 10 proved to be the best for growth and antimicrobial activities of Synechococcus spp. in BG11 medium
Full Text Available Pteropus poliocephalus (grey-headed flying foxes are recognised vectors for a range of potentially fatal human pathogens. However, to date research has primarily focused on viral disease carriage, overlooking bacterial pathogens, which also represent a significant human disease risk. The current study applied 16S rRNA amplicon sequencing, community analysis and a multi-tiered database OTU picking approach to identify faecal-derived zoonotic bacteria within two colonies of P. poliocephalus from Victoria, Australia. Our data show that sequences associated with Enterobacteriaceae (62.8% ± 24.7%, Pasteurellaceae (19.9% ± 25.7% and Moraxellaceae (9.4% ± 11.8% dominate flying fox faeces. Further colony specific differences in bacterial faecal colonisation patterns were also identified. In total, 34 potential pathogens, representing 15 genera, were identified. However, species level definition was only possible for Clostridium perfringens, which likely represents a low infectious risk due to the low proportion observed within the faeces and high infectious dose required for transmission. In contrast, sequences associated with other pathogenic species clusters such as Haemophilus haemolyticus-H. influenzae and Salmonella bongori-S. enterica, were present at high proportions in the faeces, and due to their relatively low infectious doses and modes of transmissions, represent a greater potential human disease risk. These analyses of the microbial community composition of Pteropus poliocephalus have significantly advanced our understanding of the potential bacterial disease risk associated with flying foxes and should direct future epidemiological and quantitative microbial risk assessments to further define the health risks presented by these animals.
Schmid-Siegert, Emanuel; Richard, Sophie; Luraschi, Amanda; Mühlethaler, Konrad; Pagni, Marco; Hauser, Philippe M
Microbial pathogens commonly escape the human immune system by varying surface proteins. We investigated the mechanisms used for that purpose by Pneumocystis jirovecii This uncultivable fungus is an obligate pulmonary pathogen that in immunocompromised individuals causes pneumonia, a major life-threatening infection. Long-read PacBio sequencing was used to assemble a core of subtelomeres of a single P. jirovecii strain from a bronchoalveolar lavage fluid specimen from a single patient. A total of 113 genes encoding surface proteins were identified, including 28 pseudogenes. These genes formed a subtelomeric gene superfamily, which included five families encoding adhesive glycosylphosphatidylinositol (GPI)-anchored glycoproteins and one family encoding excreted glycoproteins. Numerical analyses suggested that diversification of the glycoproteins relies on mosaic genes created by ectopic recombination and occurs only within each family. DNA motifs suggested that all genes are expressed independently, except those of the family encoding the most abundant surface glycoproteins, which are subject to mutually exclusive expression. PCR analyses showed that exchange of the expressed gene of the latter family occurs frequently, possibly favored by the location of the genes proximal to the telomere because this allows concomitant telomere exchange. Our observations suggest that (i) the P. jirovecii cell surface is made of a complex mixture of different surface proteins, with a majority of a single isoform of the most abundant glycoprotein, (ii) genetic mosaicism within each family ensures variation of the glycoproteins, and (iii) the strategy of the fungus consists of the continuous production of new subpopulations composed of cells that are antigenically different. IMPORTANCE Pneumocystis jirovecii is a fungus causing severe pneumonia in immunocompromised individuals. It is the second most frequent life-threatening invasive fungal infection. We have studied the mechanisms
Full Text Available To better understand the health implications of personal genomes, we now face a largely unmet challenge to identify functional variants within disease-associated genes. Functional variants can be identified by trans-species complementation, e.g., by failure to rescue a yeast strain bearing a mutation in an orthologous human gene. Although orthologous complementation assays are powerful predictors of pathogenic variation, they are available for only a few percent of human disease genes. Here we systematically examine the question of whether complementation assays based on paralogy relationships can expand the number of human disease genes with functional variant detection assays. We tested over 1,000 paralogous human-yeast gene pairs for complementation, yielding 34 complementation relationships, of which 33 (97% were novel. We found that paralog-based assays identified disease variants with success on par with that of orthology-based assays. Combining all homology-based assay results, we found that complementation can often identify pathogenic variants outside the homologous sequence region, presumably because of global effects on protein folding or stability. Within our search space, paralogy-based complementation more than doubled the number of human disease genes with a yeast-based complementation assay for disease variation.
Rezig, Dorra; Ben Farhat, Essia; Touzi, Henda; Meddeb, Zina; Ben Salah, Afif; Triki, Henda
A new picornavirus, named human Cosavirus (HCoSV) was isolated recently from stools of children with acute flaccid paralysis (AFP) and healthy children in Pakistan and Afghanistan. Since then, it was also isolated from patients from other countries. Five species are presently identified forming a new genus in the Picornaviridae family. This study reports the detection of HCoSV in stool specimens collected as part of the National Poliovirus surveillance Program in Tunisia, between 2011 and 2012, from patients with AFP and healthy individuals among their contacts. One hundred and ninety four stool samples were investigated by RT-PCR in the 5' non-coding region of the genome. A total of 64 specimens (33%) tested positive for HCoSV. HCoSV positive specimens were found in 36 cases with neurological syndromes and 28 of their healthy contacts. The highest rate of HCoSV infection (62.5%) occurred in children younger than 6 years of age. The sampling date of stool specimens suggested that HCoSV infection occurred regularly over time. Also, the sampling origin of stool specimen showed that HCoSV infection was detected in almost all the governorates of Tunisia from the North to the South of the country. This study is the first report of HCoSV prevalence in the North African region. It contributes to a better knowledge on the geographic distribution and the epidemiology of these viruses. © 2015 Wiley Periodicals, Inc.
Osman, Kamelia M; Samir, Ahmed; Orabi, Ahmed; Zolnikov, Tara Rava
She-camel milk is an alternative solution for people allergic to milk; unfortunately, potential harmful bacteria have not been tested in she-camel milk. Listeria monocytogenes is one harmful bacterium that causes adverse health effects if chronically or acutely ingested by humans. The purpose of this study was to estimate the prevalence, characterize the phenotypic, genetic characterization, virulence factors, and antibiopotential harmful bacteria resistance profile of Listeria isolated from the milk of she-camel. Udder milk samples were collected from 100 she-camels and screened for mastitis using the California mastitis test (46 healthy female camels, 24 subclinical mastitic animals and 30 clinical mastitic animals). Samples were then examined for the presence of pathogenic Listeria spp; if located, the isolation of Listeria was completed using the International Organization for Standards technique to test for pathogenicity. The isolates were subjected to PCR assay for virulence-associated genes. Listeria spp. were isolated from 4% of samples and only 1.0% was confirmed as L. monocytogenes. The results of this study provide evidence for the low prevalence of intramammary Listeria infection; additionally, this study concludes she-camel milk in healthy camels milked and harvested in proper hygienic conditions may be used as alternative milk for human consumption. Copyright © 2013 Elsevier B.V. All rights reserved.
Arroyo-López, Francisco N; Blanquet-Diot, Stéphanie; Denis, Sylvain; Thévenot, Jonathan; Chalancon, Sandrine; Alric, Monique; Rodríguez-Gómez, Francisco; Romero-Gil, Verónica; Jiménez-Díaz, Rufino; Garrido-Fernández, Antonio
The present survey uses a dynamic gastric and small intestinal model to assess the survival of one pathogenic (Escherichia coli O157:H7 EDL 933) and three lactobacilli bacteria with probiotic potential (Lactobacillus rhamnosus GG, L. pentosus TOMC-LAB2, and L. pentosus TOMC-LAB4) during their passage through the human gastrointestinal tract using fermented olives as the food matrix. The data showed that the survival of the E. coli strain in the stomach and duodenum was very low, while its transit through the distal parts (jejunum and ileum) resulted in an increase in the pathogen population. The production of Shiga toxins by this enterohemorrhagic microorganism in the ileal eﬄuents of the in vitro system was too low to be detected by ELISA assays. On the contrary, the three lactobacilli species assayed showed a considerable resistance to the gastric digestion, but not to the intestinal one, which affected their survival, and was especially evident in the case of both L. pentosus strains. In spite of this, high population levels for all assayed microorganisms were recovered at the end of the gastrointestinal passage. The results obtained in the present study show the potential use of table olives as a vehicle of beneficial microorganisms to the human body, as well as the need for good hygienic practices on the part of olive manufacturers in order to avoid the possibility of contamination by food-borne pathogens.
Francisco Noé eArroyo López
Full Text Available The present survey uses a dynamic gastric and small intestinal model to assess the survival of one pathogenic (Escherichia coli O157:H7 EDL 933 and three lactobacilli bacteria with probiotic potential (Lactobacillus rhamnosus GG, Lactobacillus pentosus TOMC-LAB2 and Lactobacillus pentosus TOMC-LAB4 during their passage through the human gastrointestinal tract using fermented olives as the food matrix. The data showed that the survival of the E. coli strain in the stomach and duodenum was very low, while its transit through the distal parts (jejunum and ileum resulted in an increase in the pathogen population. The production of Shiga toxins by this enterohemorrhagic microorganism in the ileal effluents of the in vitro system was too low to be detected by ELISA assays. On the contrary, the three lactobacilli species assayed showed a considerable resistance to the gastric digestion, but not to the intestinal one, which affected their survival, and was especially evident in the case of both L. pentosus strains. In spite of this, high population levels for all assayed microorganisms were recovered at the end of the gastrointestinal passage. The results obtained in the present study show the potential use of table olives as a vehicle of beneficial microorganisms to the human body, as well as the need for good hygienic practices on the part of olive manufacturers in order to avoid the possibility of contamination by food-borne pathogens.
Pérez-Rodríguez, Ileana; Bolognini, Marie; Ricci, Jessica; Bini, Elisabetta; Vetriani, Costantino
Chemosynthetic Epsilonproteobacteria from deep-sea hydrothermal vents colonize substrates exposed to steep thermal and redox gradients. In many bacteria, substrate attachment, biofilm formation, expression of virulence genes and host colonization are partly controlled via a cell density-dependent mechanism involving signal molecules, known as quorum sensing. Within the Epsilonproteobacteria, quorum sensing has been investigated only in human pathogens that use the luxS/autoinducer-2 (AI-2) mechanism to control the expression of some of these functions. In this study we showed that luxS is conserved in Epsilonproteobacteria and that pathogenic and mesophilic members of this class inherited this gene from a thermophilic ancestor. Furthermore, we provide evidence that the luxS gene is expressed--and a quorum-sensing signal is produced--during growth of Sulfurovum lithotrophicum and Caminibacter mediatlanticus, two Epsilonproteobacteria from deep-sea hydrothermal vents. Finally, we detected luxS transcripts in Epsilonproteobacteria-dominated biofilm communities collected from deep-sea hydrothermal vents. Taken together, our findings indicate that the epsiloproteobacterial lineage of the LuxS enzyme originated in high-temperature geothermal environments and that, in vent Epsilonproteobacteria, luxS expression is linked to the production of AI-2 signals, which are likely produced in situ at deep-sea vents. We conclude that the luxS gene is part of the ancestral epsilonproteobacterial genome and represents an evolutionary link that connects thermophiles to human pathogens.
Ke, Changwen; Mok, Chris Ka Pun; Zhu, Wenfei; Zhou, Haibo; He, Jianfeng; Guan, Wenda; Wu, Jie; Song, Wenjun; Wang, Dayan; Liu, Jiexiong; Lin, Qinhan; Chu, Daniel Ka Wing; Yang, Lei; Zhong, Nanshan; Yang, Zifeng; Shu, Yuelong; Peiris, Joseph Sriyal Malik
The recent increase in zoonotic avian influenza A(H7N9) disease in China is a cause of public health concern. Most of the A(H7N9) viruses previously reported have been of low pathogenicity. We report the fatal case of a patient in China who was infected with an A(H7N9) virus having a polybasic amino acid sequence at its hemagglutinin cleavage site (PEVPKRKRTAR/GL), a sequence suggestive of high pathogenicity in birds. Its neuraminidase also had R292K, an amino acid change known to be associated with neuraminidase inhibitor resistance. Both of these molecular features might have contributed to the patient's adverse clinical outcome. The patient had a history of exposure to sick and dying poultry, and his close contacts had no evidence of A(H7N9) disease, suggesting human-to-human transmission did not occur. Enhanced surveillance is needed to determine whether this highly pathogenic avian influenza A(H7N9) virus will continue to spread.
Rosser, Tracy; Allison, Lesley J.; Courcier, Emily; Evans, Judith; McKendrick, Iain J.; Pearce, Michael C.; Handel, Ian; Caprioli, Alfredo; Karch, Helge; Hanson, Mary F.; Pollock, Kevin G.J.; Locking, Mary E.; Woolhouse, Mark E.J.; Matthews, Louise; Low, J. Chris; Gally, David L.
Escherichia coli O26 and O157 have similar overall prevalences in cattle in Scotland, but in humans, Shiga toxin–producing E. coli O26 infections are fewer and clinically less severe than E. coli O157 infections. To investigate this discrepancy, we genotyped E. coli O26 isolates from cattle and humans in Scotland and continental Europe. The genetic background of some strains from Scotland was closely related to that of strains causing severe infections in Europe. Nonmetric multidimensional scaling found an association between hemolytic uremic syndrome (HUS) and multilocus sequence type 21 strains and confirmed the role of stx2 in severe human disease. Although the prevalences of E. coli O26 and O157 on cattle farms in Scotland are equivalent, prevalence of more virulent strains is low, reducing human infection risk. However, new data on E. coli O26–associated HUS in humans highlight the need for surveillance of non-O157 enterohemorrhagic E. coli and for understanding stx2 phage acquisition. PMID:22377426
Syed, Baker; M N, Nagendra Prasad; K, Mohan Kumar; B L, Dhananjaya; Satish, Sreedharamurthy
Synthesis of gold nanobactericides (AuNBs) were achieved by treating 1mM chloroaurate with cell free supernatant of Aneurinibacillus migulanus. Formation of AuNBs was initially was monitored with change in colour to ruby red. Further confirmation was assessed with UV-visible spectra with maximum absorption occurring at 510nm. Transmission electron microscopy (TEM) analysis revealed the polydispersity of AuNBs with size distribution ranging from 10 to 60nm with an average size of 30nm. Crystalline nature was studied using X-ray diffraction which exhibited characteristic peaks indexed to Bragg's reflection at 2θ angle which confers (111), (200), (220), and (311) planes suggesting AuNBs were face-centred cubic. Fourier transform infrared spectroscopy (FTIR) analysis revealed absorption peaks occurring at 3341cm -1 , 1635cm -1 and 670cm -1 which corresponds to functional groups attributing to synthesis. The antibacterial efficacy of AuNBs was tested against selective human pathogenic bacteria and activity was measured as zone of inhibition by using disc and well diffusion. Bactericidal activity was interpreted with standard antibiotics gentamicin and kanamycin. Micro broth dilution assay expressed the minimal concentration of AuNBs to inhibit the growth of test pathogens. Highest activity was observed against Pseudomonas aeruginosa (MTCC 7903) with 21.00±0.57mm compared to other pathogens. The possible mode of action of AuNBs on DNA was carried out with in vitro assay as preliminary test against pathogenic DNA isolated from P. aeruginosa. Further studies will be interesting enough to reveal the exact interactive mechanism of AuNBs with DNA. Overall study contributes towards biogenic synthesis of AuNBs as one of the alternative in combating drug resistant pathogens. Copyright © 2017 Elsevier B.V. All rights reserved.
Marcos, Miguel; Soriano, Alex; Iñurrieta, Amaia; Martínez, José A; Romero, Alberto; Cobos, Nazaret; Hernández, Cristina; Almela, Manel; Marco, Francesc; Mensa, Josep
Gram-positive microorganisms have been the predominant pathogens in central venous catheter-related bloodstream infections (CRBSIs). Recent guidelines recommend empirical therapy according to this and restrict coverage for Gram-negatives to specific circumstances. This study aimed to analyse the epidemiological changes in CRBSIs over the 1991-2008 period and to analyse predictors of Gram-negative CRBSIs. A prospectively collected cohort of patients with confirmed CRBSIs was analysed. Strains isolated and antimicrobial susceptibility, as well as clinical and demographic variables were recorded. Differences observed during the study period were analysed by means of a χ² trend test and factors associated with Gram-negative CRBSIs by means of multivariable analysis. Between 1991 and 2008, 1129 episodes of monomicrobial CRBSIs were recorded. There was an increase in the incidence of CRBSIs, from 0.10 (1991-92) to 0.31 (2007-08) episodes/1000 patient-days. A significant increase in the number of Gram-negative strains among the total isolates was also found, from 3 (4.7%) in 1991-92 to 70 (40.23%) in 2007-08, with a parallel decrease in the percentage of Gram-positives. Solid organ transplantation, prior use of penicillins and hospital stay longer than 11 days were independently associated with a significantly higher risk of Gram-negative CRBSIs, while cirrhosis, diabetes and use of quinolones were associated with a higher risk of Gram-positives. Gram-negative strains are an increasing cause of CRBSIs, reaching a prevalence of 40% in the 2007-08 period in our hospital. If this trend is confirmed in other centres, a broad-spectrum empirical therapy should be considered in managing these infections.
Marina Tayla Mesquita Aguiar
Full Text Available Anal cancer is relatively rare; however, its incidence has increased in recent years. Several risk factors are associated with the development of anal cancer, including age older than 50 years, low-fiber diet, chronic anal fistulas, smoking, multiple partners, anal intercourse practice, Human Immunodeficiency Virus infection and immunosuppression. However, the presence of human papillomavirus represents the main risk factor for the development of anal cancer. The aim of this study was to evaluate the clinicopathological aspects of a series of patients with anal carcinomas diagnosed in Hospital Araújo Jorge, Goiânia-Goiás, as well as the prevalence of human papillomavirus genome in these tumors. Clinical, pathological and socio-demographic data were collected from the respective medical files and paraffin blocks containing anal carcinomas specimens were used for DNA extraction and detection of human papillomavirus, by means of polymerase chain reaction, using short PCR fragment primers. Forty-three cases were selected and had the data analyzed, while 38 cases were tested for human papillomavirus genome detection. Among the evaluated patients, 62.8% were women; 53.4% of tumors were squamous cell carcinoma and 46.5% of the patients were aged between 60 and 75 years. Risk factors, such as smoking (39.5% and alcoholism (20.9% were recorded in the studied group. Lymph node metastases were detected in 30.2% of cases and 7.0% had distant metastasis. The detection of human papillomavirus DNA was positive in 76% of cases assessed and this was significantly associated with squamous cell carcinomas. Aggressive behavior and advanced stage of anal cancer described in this study highlight the need for preventive measures that contemplate these tumors, including vaccination against human papillomavirus. Resumo: O câncer anal é relativamente raro, entretanto, sua incidência aumentou nos últimos anos. Vários fatores de risco são associados ao
Awan, Uzma Azeem; Andleeb, Saiqa; Kiyani, Ayesha; Zafar, Atiya; Shafique, Irsa; Riaz, Nazia; Azhar, Muhammad Tehseen; Uddin, Hafeez
Chloroformic and isoamyl alcohol extracts of Cinnnamomum zylanicum, Cuminum cyminum, Curcuma long Linn, Trachyspermum ammi and selected standard antibiotics were investigated for their in vitro antibacterial activity against six human bacterial pathogens. The antibacterial activity was evaluated and based on the zone of inhibition using agar disc diffusion method. The tested bacterial strains were Streptococcus pyogenes, Staphylococcus epidermidis, Klebsiella pneumonia, Staphylococcus aurues, Serratia marcesnces, and Pseudomonas aeruginosa. Ciprofloxacin showed highly significant action against K. pneumonia and S. epidermidis while Ampicillin and Amoxicillin indicated lowest antibacterial activity against tested pathogens. Among the plants chloroform and isoamyl alcohol extracts of C. cyminum, S. aromaticum and C. long Linn had significant effect against P. aeruginosa, S. marcesnces and S. pyogenes. Comparison of antibacterial activity of medicinal herbs and standard antibiotics was also recorded via activity index. Used medicinal plants have various phytochemicals which reasonably justify their use as antibacterial agent.
Leydet, Brian F; Liang, Fang-Ting
There are 4 major human-biting tick species in the northeastern United States, which include: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. The black bear is a large mammal that has been shown to be parasitized by all the aforementioned ticks. We investigated the bacterial infections in ticks collected from Louisiana black bears (Ursus americanus subspecies luteolus). Eighty-six ticks were collected from 17 black bears in Louisiana from June 2010 to March 2011. All 4 common human-biting tick species were represented. Each tick was subjected to polymerase chain reaction (PCR) targeting select bacterial pathogens and symbionts. Bacterial DNA was detected in 62% of ticks (n=53). Rickettsia parkeri, the causative agent of an emerging spotted fever group rickettsiosis, was identified in 66% of A. maculatum, 28% of D. variabilis, and 11% of I. scapularis. The Lyme disease bacterium, Borrelia burgdorferi, was detected in 2 I. scapularis, while one A. americanum was positive for Borrelia bissettii, a putative human pathogen. The rickettsial endosymbionts Candidatus Rickettsia andeanae, rickettsial endosymbiont of I. scapularis, and Rickettsia amblyommii were detected in their common tick hosts at 21%, 39%, and 60%, respectively. All ticks were PCR-negative for Anaplasma phagocytophilum, Ehrlichia spp., and Babesia microti. This is the first reported detection of R. parkeri in vector ticks in Louisiana; we also report the novel association of R. parkeri with I. scapularis. Detection of both R. parkeri and B. burgdorferi in their respective vectors in Louisiana demands further investigation to determine potential for human exposure to these pathogens. Copyright © 2013 Elsevier GmbH. All rights reserved.
Tann, Cally J; Nkurunziza, Peter; Nakakeeto, Margaret; Oweka, James; Kurinczuk, Jennifer J; Were, Jackson; Nyombi, Natasha; Hughes, Peter; Willey, Barbara A; Elliott, Alison M; Robertson, Nicola J; Klein, Nigel; Harris, Kathryn A
In neonatal encephalopathy (NE), infectious co-morbidity is difficult to diagnose accurately, but may increase the vulnerability of the developing brain to hypoxia-ischemia. We developed a novel panel of species-specific real-time PCR assays to identify bloodstream pathogens amongst newborns with and without NE in Uganda. Multiplex real-time PCR assays for important neonatal bloodstream pathogens (gram positive and gram negative bacteria, cytomegalovirus (CMV), herpes simplex virus(HSV) and P. falciparum) were performed on whole blood taken from 202 encephalopathic and 101 control infants. Automated blood culture (BACTEC) was performed for all cases and unwell controls. Prevalence of pathogenic bacterial species amongst infants with NE was 3.6%, 6.9% and 8.9%, with culture, PCR and both tests in combination, respectively. More encephalopathic infants than controls had pathogenic bacterial species detected (8.9%vs2.0%, p = 0.028) using culture and PCR in combination. PCR detected bacteremia in 11 culture negative encephalopathic infants (3 Group B Streptococcus, 1 Group A Streptococcus, 1 Staphylococcus aureus and 6 Enterobacteriacae). Coagulase negative staphylococcus, frequently detected by PCR amongst case and control infants, was considered a contaminant. Prevalence of CMV, HSV and malaria amongst cases was low (1.5%, 0.5% and 0.5%, respectively). This real-time PCR panel detected more bacteremia than culture alone and provides a novel tool for detection of neonatal bloodstream pathogens that may be applied across a range of clinical situations and settings. Significantly more encephalopathic infants than controls had pathogenic bacterial species detected suggesting that infection may be an important risk factor for NE in this setting.
Cally J Tann
Full Text Available In neonatal encephalopathy (NE, infectious co-morbidity is difficult to diagnose accurately, but may increase the vulnerability of the developing brain to hypoxia-ischemia. We developed a novel panel of species-specific real-time PCR assays to identify bloodstream pathogens amongst newborns with and without NE in Uganda.Multiplex real-time PCR assays for important neonatal bloodstream pathogens (gram positive and gram negative bacteria, cytomegalovirus (CMV, herpes simplex virus(HSV and P. falciparum were performed on whole blood taken from 202 encephalopathic and 101 control infants. Automated blood culture (BACTEC was performed for all cases and unwell controls.Prevalence of pathogenic bacterial species amongst infants with NE was 3.6%, 6.9% and 8.9%, with culture, PCR and both tests in combination, respectively. More encephalopathic infants than controls had pathogenic bacterial species detected (8.9%vs2.0%, p = 0.028 using culture and PCR in combination. PCR detected bacteremia in 11 culture negative encephalopathic infants (3 Group B Streptococcus, 1 Group A Streptococcus, 1 Staphylococcus aureus and 6 Enterobacteriacae. Coagulase negative staphylococcus, frequently detected by PCR amongst case and control infants, was considered a contaminant. Prevalence of CMV, HSV and malaria amongst cases was low (1.5%, 0.5% and 0.5%, respectively.This real-time PCR panel detected more bacteremia than culture alone and provides a novel tool for detection of neonatal bloodstream pathogens that may be applied across a range of clinical situations and settings. Significantly more encephalopathic infants than controls had pathogenic bacterial species detected suggesting that infection may be an important risk factor for NE in this setting.
Background. Hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV are common blood-borne infections unevenly distributed across regions in Nigeria. Few population-based prevalence studies have been done in Nigeria. Objective. To determine the prevalence of HBV, HCV and HIV and risk factors for infection with ...
RESULTS. Demographic characteristics revealed that the prevalence of rhinovirus infection in children showed 38% positivity of which 20 (10.0%) were males while 17 (8.5%) were females. Children between the ages ofO-24 months have the highest prevalence of 45.9% while those older than 96 months have the least.
most sexually active individuals are exposed to and acquire infection from this virus at some phase in their lives.[2,3] HPV infection is most prevalent in young adults, at the beginning of their sexual activity, with a subsequent decline in the prevalence with increasing age, likely a result of the development of an immune ...
Chibucos, Marcus C.; Crabtree, Jonathan; Nagaraj, Sushma; Chaturvedi, Sudha; Chaturvedi, Vishnu
We report the draft genome sequences of Geomyces pannorum sensu lato and Geomyces (Pseudogymnoascus) destructans. G.?pannorum has a larger proteome than G.?destructans, containing more proteins with ascribed enzymatic functions. This dichotomy in the genomes of related psychrophilic fungi is a valuable target for defining their distinct saprobic and pathogenic attributes.
Chibucos, Marcus C; Crabtree, Jonathan; Nagaraj, Sushma; Chaturvedi, Sudha; Chaturvedi, Vishnu
We report the draft genome sequences of Geomyces pannorum sensu lato and Geomyces (Pseudogymnoascus) destructans. G. pannorum has a larger proteome than G. destructans, containing more proteins with ascribed enzymatic functions. This dichotomy in the genomes of related psychrophilic fungi is a valuable target for defining their distinct saprobic and pathogenic attributes.
Sun, Mingwei; Zheng, Beiwen; Gao, George F; Zhu, Baoli
Throughout human history, pandemic bacterial diseases such as the plague and tuberculosis have posed an enormous threat to human beings. The discovery of antibiotics has provided us with powerful arsenal for the defense against bacterial infections. However, bacteria are acquiring more and more resistance genes to shield off antibiotics through mutation and horizontal gene transfer. Therefore, novel antibiotics must be produced and the arms race between bacterial pathogens and antibiotics is becoming increasingly intense. Recently, researchers have found that plasmids carrying a new metallo-beta-lactamase gene, blaNDM-1, and many other antibiotics resistance genes can easily spread through bacterial populations and confer recipient stains resistance to nearly all of the current antibiotics. It is a threat to the human health and a great challenge for our medical science, which we are facing. We need to find new ways to fight and win this arms racing.
Mufinda, Franco Cazembe; Boinas, Fernando; Nunes, Carla
The objective of this study is to estimate the seroprevalence of human brucellosis in livestock professionals and analyze the factors associated with brucellosis focusing on sociodemographic variables and the variables of knowledge and practices related to the characteristics of the activities carried out in livestock. This is a cross-sectional seroepidemiological study with a population of 131 workers of butchers, slaughter rooms, and slaughterhouse and 192 breeders sampled randomly in Namibe province, Angola. The data were obtained from the collection of blood and use of questionnaires. The laboratory tests used were rose bengal and slow agglutination. The questionnaire allowed us to collect sociodemographic information and, specifically on brucellosis, it incorporated questions about knowledge, attitudes, and behaviors of livestock professionals. In addition to the descriptive statistical approach, we used the Chi-square test of independence, Fisher's test, and logistic regression models, using a significance level of 10%. The general weighted prevalence of brucellosis was 15.6% (95%CI 13.61-17.50), being it 5.3% in workers and 16.7% (95%CI 11.39-21.93) in breeders. The statistical significance was observed between human seroprevalence and category (worker and breeder) (p brucellosis in professionals was the professional category (OR = 3.54; 95%CI 1.57-8.30, related to breeders in relation to workers). Human brucellosis in livestock professionals is prevalent in Namibe province (15.6%), where the professional category was the most important factor. The seroprevalence levels detected are high when compared with those found in similar studies. Estimar a seroprevalência da brucelose humana em profissionais da pecuária e analisar os factores associados à brucelose com foco em variáveis sociodemográficas, de conhecimento e práticas relativas às características das actividades desenvolvidas na pecuária. Estudo transversal seroepidemiológico em população de
Hossein, Rassi; Behzad, Salehi; Tahar, Mohammadian; Azadeh, Nahavandi Araghi
Cancer is a multi-step disease, and infection with a DNA virus could play a role in one or more of the steps in this pathogenic process. High-risk human papillomaviruses (HPV) are the causative agent of several cancers. In this study, we determined the prevalence and genotype distribution of HPV infection among Iranian patients with cervix lesions (CL) and breast cancer (BC). The study group consisted of postoperative tissues from patients diagnosed with cervix lesions and breast cancer. We analyzed 250 formalin-fixed, paraffin-embedded tissue blocks from 100 cervix lesions and 150 breast cancer samples. Verification of each cancer reported in a relative was sought through the pathology reports of the hospital records. Cervix lesions were collected from 100 patients with squamous metaplasia (SM, n=50), cervical intraepithelial neoplasia (CINI, n=18, CINII or III, n=8), and cervical carcinoma (CC, n=24). In this study we evaluated the prevalence of HPV by multiplex PCR in cervix lesions and breast cancer. For paraffin-embedded tissues, DNA extracted by the simple boiling method yielded higher proportions of successful gene amplification (99%) for b-actin gene. Overall prevalence of HPV infection was 6% in the SM group, 34.61% in the CIN group, 75% in the CC group, and 34.66% in the BC group. Furthermore, MY09/11 consensus PCR failed to detect 44 (55.69%) of all HPV infections and interestingly, the predominant genotype detected in all cancers was the oncogenic variant HPV16/18; about 34% of women aged 24 to 54 were infected with at least one type of HPV. Our results demonstrate that DNA derived from archival tissues that archived for less than 8 years could be used successfully for HPV genotyping by multiplex PCR. Infection with HPV was prevalent among Iranian women with CC and BC. The results indicate a likely causal role for high-risk HPV in CC and BC, and also offer the possibility of primary prevention of these cancers by vaccination against HPV in Iran.
Thomassen, Henri A.; Fuller, Trevon; Asefi-Najafabady, Salvi; Shiplacoff, Julia A. G.; Mulembakani, Prime M.; Blumberg, Seth; Johnston, Sara C.; Kisalu, Neville K.; Kinkela, Timothée L.; Fair, Joseph N.; Wolfe, Nathan D.; Shongo, Robert L.; LeBreton, Matthew; Meyer, Hermann; Wright, Linda L.; Muyembe, Jean-Jacques; Buermann, Wolfgang; Okitolonda, Emile; Hensley, Lisa E.; Lloyd-Smith, James O.; Smith, Thomas B.; Rimoin, Anne W.
Climate change is predicted to result in changes in the geographic ranges and local prevalence of infectious diseases, either through direct effects on the pathogen, or indirectly through range shifts in vector and reservoir species. To better understand the occurrence of monkeypox virus (MPXV), an emerging Orthopoxvirus in humans, under contemporary and future climate conditions, we used ecological niche modeling techniques in conjunction with climate and remote-sensing variables. We first created spatially explicit probability distributions of its candidate reservoir species in Africa's Congo Basin. Reservoir species distributions were subsequently used to model current and projected future distributions of human monkeypox (MPX). Results indicate that forest clearing and climate are significant driving factors of the transmission of MPX from wildlife to humans under current climate conditions. Models under contemporary climate conditions performed well, as indicated by high values for the area under the receiver operator curve (AUC), and tests on spatially randomly and non-randomly omitted test data. Future projections were made on IPCC 4th Assessment climate change scenarios for 2050 and 2080, ranging from more conservative to more aggressive, and representing the potential variation within which range shifts can be expected to occur. Future projections showed range shifts into regions where MPX has not been recorded previously. Increased suitability for MPX was predicted in eastern Democratic Republic of Congo. Models developed here are useful for identifying areas where environmental conditions may become more suitable for human MPX; targeting candidate reservoir species for future screening efforts; and prioritizing regions for future MPX surveillance efforts. PMID:23935820
Janda, J Michael; Abbott, Sharon L
The genus Shewanella is currently composed of more than 50 species that inhabit a range of marine environs and ecosystems. Several members of this genus, including S. oneidensis, have been identified that could potentially play key roles in environmental processes such as bioremediation of toxic elements and heavy metals and serving as microbial fuel cells. In contrast to this beneficial role, shewanellae are increasingly being implicated as human pathogens in persons exposed through occupational or recreational activities to marine niches containing shewanellae. Documented illnesses linked to Shewanella include skin and soft tissue infections, bacteremia, and otitis media. At present, it is unclear exactly how many Shewanella species are truly bona fide human pathogens. Recent advances in the taxonomy and phylogenetic relatedness of members of this genus, however, support the concept that most human infections are caused by a single species, S. algae. Some phylogenetic data further suggest that some current members of the genus are not true Shewanella species sensu stricto. The current review summarizes our present knowledge of the distribution, epidemiology, disease spectrum, and identification of microbial species focusing on a clinical perspective.
Ziegler, Sabrina; Weiss, Esther; Schmitt, Anna-Lena; Schlegel, Jan; Burgert, Anne; Terpitz, Ulrich; Sauer, Markus; Moretta, Lorenzo; Sivori, Simona; Leonhardt, Ines; Kurzai, Oliver; Einsele, Hermann; Loeffler, Juergen
Aspergillus (A.) fumigatus is an opportunistic fungal mold inducing invasive aspergillosis (IA) in immunocompromised patients. Although antifungal activity of human natural killer (NK) cells was shown in previous studies, the underlying cellular mechanisms and pathogen recognition receptors (PRRs) are still unknown. Using flow cytometry we were able to show that the fluorescence positivity of the surface receptor CD56 significantly decreased upon fungal contact. To visualize the interaction site of NK cells and A. fumigatus we used SEM, CLSM and dSTORM techniques, which clearly demonstrated that NK cells directly interact with A. fumigatus via CD56 and that CD56 is re-organized and accumulated at this interaction site time-dependently. The inhibition of the cytoskeleton showed that the receptor re-organization was an active process dependent on actin re-arrangements. Furthermore, we could show that CD56 plays a role in the fungus mediated NK cell activation, since blocking of CD56 surface receptor reduced fungal mediated NK cell activation and reduced cytokine secretion. These results confirmed the direct interaction of NK cells and A. fumigatus, leading to the conclusion that CD56 is a pathogen recognition receptor. These findings give new insights into the functional role of CD56 in the pathogen recognition during the innate immune response.
Full Text Available Under the present investigation Actinomycetes were isolated from the soils of Myristica swamps of southern Western Ghats and the antagonistic activity against different human bacterial pathogens was evaluated. Results of the present study revealed that Actinomycetes population in the soils of Myristica swamp was spatially and seasonally varied. Actinomycetes load was varied from 24×104 to 71×103, from 129×103 to 40×103 and from 31×104 to 84×103 in post monsoon, monsoon and pre monsoon respectively. A total of 23 Actinomycetes strains belonging to six genera were isolated from swamp soils. Identification of the isolates showed that most of the isolates belonged to the genus Streptomyces (11, followed by Nocardia (6, Micromonospora (3, Pseudonocardia (1, Streptosporangium (1, and Nocardiopsis (1. Antagonistic studies revealed that 91.3% of Actinomycete isolates were active against one or more tested pathogens, of that 56.52% exhibited activity against Gram negative and 86.95% showed activity against Gram positive bacteria. 39.13% isolates were active against all the bacterial pathogens selected and its inhibition zone diameter was also high. 69.5% of Actinomycetes were exhibited antibacterial activity against Listeria followed by Bacillus cereus (65.21%, Staphylococcus (60.86%, Vibrio cholera (52.17%, Salmonella (52.17% and E. coli (39.13%. The results indicate that the Myristica swamp soils of Southern Western Ghats might be a remarkable reserve of Actinomycetes with potential antagonistic activity.
Casati, Simona; Sager, Heinz; Gern, Lise; Piffaretti, Jean-Claude
We have designed and performed a new PCR method based on the 18S rRNA in order to individuate the presence and the identity of Babesia parasites. Out of 1159 Ixodes ricinus (Acari: Ixodidae) ticks collected in four areas of Switzerland, nine were found to contain Babesia DNA. Sequencing of the short amplicon obtained (411-452 bp) allowed the identification of three human pathogenic species: Babesia microti, B. divergens, for the first time in Switzerland, Babesia sp. EU1. We also report coinfections with B. sp. EU1-Borrelia burgdorferi sensu stricto and Babesia sp. EU1-B. afzelii.
Loftus, Brendan J.; Fung, Eula; Roncaglia, Paola; Rowley, Don; Amedeo, Paolo; Bruno, Dan; Vamathevan, Jessica; Miranda, Molly; Anderson, Iain J.; Fraser, James A.; Allen, Jonathan E.; Bosdet, Ian E.; Brent, Michael R.; Chiu, Readman; Doering, Tamara L.; Donlin, Maureen J.; D’Souza, Cletus A.; Fox, Deborah S.; Grinberg, Viktoriya; Fu, Jianmin; Fukushima, Marilyn; Haas, Brian J.; Huang, James C.; Janbon, Guilhem; Jones, Steven J. M.; Koo, Hean L.; Krzywinski, Martin I.; Kwon-Chung, June K.; Lengeler, Klaus B.; Maiti, Rama; Marra, Marco A.; Marra, Robert E.; Mathewson, Carrie A.; Mitchell, Thomas G.; Pertea, Mihaela; Riggs, Florenta R.; Salzberg, Steven L.; Schein, Jacqueline E.; Shvartsbeyn, Alla; Shin, Heesun; Shumway, Martin; Specht, Charles A.; Suh, Bernard B.; Tenney, Aaron; Utterback, Terry R.; Wickes, Brian L.; Wortman, Jennifer R.; Wye, Natasja H.; Kronstad, James W.; Lodge, Jennifer K.; Heitman, Joseph; Davis, Ronald W.; Fraser, Claire M.; Hyman, Richard W.
Cryptococcus neoformans is a basidiomycetous yeast ubiquitous in the environment, a model for fungal pathogenesis, and an opportunistic human pathogen of global importance. We have sequenced its ~20-megabase genome, which contains ~6500 intron-rich gene structures and encodes a transcriptome abundant in alternatively spliced and antisense messages. The genome is rich in transposons, many of which cluster at candidate centromeric regions. The presence of these transposons may drive karyotype instability and phenotypic variation. C. neoformans encodes unique genes that may contribute to its unusual virulence properties, and comparison of two phenotypically distinct strains reveals variation in gene content in addition to sequence polymorphisms between the genomes. PMID:15653466
Ye, Y W; Ling, N; Han, Y J; Wu, Q P
Pathogenic Yersinia enterocolitica is involved in yersiniosis through expression of chromosome-borne or plasmid-borne virulence factors. Yersinia enterocolitica is a cold-tolerant pathogen frequently isolated from refrigerated or frozen foods. However, little attention has been focused on the prevalence of pathogenic Y. enterocolitica in refrigerated or frozen dairy samples in China. In this study, we developed a new duplex PCR targeting the plasmid-borne virF gene and chromosome-borne ail gene for detection of pathogenic Y. enterocolitica isolates. We established a detection limit for the duplex PCR of 6.5 × 10(2)cfu/mL in artificially contaminated dairy samples. In addition, the duplex PCR could detect directly 4.5 to 5.7 cfu of Y. enterocolitica in 5 mL of brain heart infusion broth after 6 h of enrichment at 28 °C. A newly developed dot hybridization assay further confirmed specificity of the duplex PCR for detection of virulent Y. enterocolitica. Furthermore, 13 Y. enterocolitica and 5 pathogenic strains, from 88 commercial frozen or refrigerated dairy products, were detected successfully by the China National Standard method (GB/T4789.8-2008) and the duplex PCR, respectively. Finally, biotypes and serotypes of pathogenic Y. enterocolitica strains were further characterized. The duplex PCR developed here is reliable for large-scale screening, routine monitoring, and risk assessment of pathogenic Y. enterocolitica in refrigerated or frozen dairy products. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Full Text Available We investigated the diversity and distribution of fungi in nine different sites inside 30 residential dishwashers. In total, 503 fungal strains were isolated, which belong to 10 genera and 84 species. Irrespective of the sampled site, 83% of the dishwashers were positive for fungi. The most frequent opportunistic pathogenic species were Exophiala dermatitidis, Candida parapsilosis sensu stricto, Exophiala phaeomuriformis, Fusarium dimerum, and the Saprochaete/Magnusiomyces clade. The black yeast E. dermatitidis was detected in 47% of the dishwashers, primarily at the dishwasher rubber seals, at up to 106 CFU/cm2; the other fungi detected were in the range of 102 to 105 CFU/cm2. The other most heavily contaminated dishwasher sites were side nozzles, doors and drains. Only F. dimerum was isolated from washed dishes, while dishwasher waste water contained E. dermatitidis, Exophiala oligosperma and Sarocladium killiense. Plumbing systems supplying water to household appliances represent the most probable route for contamination of dishwashers, as the fungi that represented the core dishwasher mycobiota were also detected in the tap water. Hot aerosols from dishwashers contained the human opportunistic yeast C. parapsilosis, Rhodotorula mucilaginosa and E. dermatitidis (as well as common air-borne genera such as Aspergillus, Penicillium, Trichoderma and Cladosporium. Comparison of fungal contamination of kitchens without and with dishwashers revealed that virtually all were contaminated with fungi. In both cases, the most contaminated sites were the kitchen drain and the dish drying rack. The most important difference was higher prevalence of black yeasts (E. dermatitidis in particular in kitchens with dishwashers. In kitchens without dishwashers, C. parapsilosis strongly prevailed with negligible occurrence of E. dermatitidis. F. dimerum was isolated only from kitchens with dishwashers, while Saprochaete/Magnusiomyces isolates were only found within
Hasaan Gassim Mohamed
Full Text Available This study compared the influence of type 2 diabetes on the occurrence of six periodontal pathogens in plaque samples of patients with and without chronic periodontitis. Levels of salivary MMP-8, MMP-9, RANKL, and OPG were also investigated. The study enrolled 31 patients with type 2 diabetes and chronic periodontitis (DM + CP, 29 with chronic periodontitis (CP, and 20 with type 2 diabetes (DM. Questionnaire-guided interviews were conducted and plaque index, bleeding on probing, and pocket depth were recorded. Polymerase chain reaction (PCR was utilized to determine the prevalence of the bacteria. The levels of salivary molecules were determined by enzyme immunosorbent assay (ELISA. The CP group had the highest prevalence of P. gingivalis (81.5%, followed by the DM + CP (59.3% and DM (55.0% groups (P>0.05. Similar trends were observed for P. intermedia and T. denticola. The prevalence of T. forsythia was 100% in both periodontitis groups compared to 90% in the DM group. There were no significant differences between the groups regarding the concentrations of MMP-8, MMP-9, or OPG. RANKL concentrations were below the detection limit. Our data show that type 2 diabetes has no significant influence on the prevalence of the investigated periodontal pathogens, or the levels of salivary MMP-8, MMP-9, and OPG.
Nathan D Grubaugh
Full Text Available Globally, regions at the highest risk for emerging infectious diseases are often the ones with the fewest resources. As a result, implementing sustainable infectious disease surveillance systems in these regions is challenging. The cost of these programs and difficulties associated with collecting, storing and transporting relevant samples have hindered them in the regions where they are most needed. Therefore, we tested the sensitivity and feasibility of a novel surveillance technique called xenosurveillance. This approach utilizes the host feeding preferences and behaviors of Anopheles gambiae, which are highly anthropophilic and rest indoors after feeding, to sample viruses in human beings. We hypothesized that mosquito bloodmeals could be used to detect vertebrate viral pathogens within realistic field collection timeframes and clinically relevant concentrations.To validate this approach, we examined variables influencing virus detection such as the duration between mosquito blood feeding and mosquito processing, the pathogen nucleic acid stability in the mosquito gut and the pathogen load present in the host's blood at the time of bloodmeal ingestion using our laboratory model. Our findings revealed that viral nucleic acids, at clinically relevant concentrations, could be detected from engorged mosquitoes for up to 24 hours post feeding by qRT-PCR. Subsequently, we tested this approach in the field by examining blood from engorged mosquitoes from two field sites in Liberia. Using next-generation sequencing and PCR we were able to detect the genetic signatures of multiple viral pathogens including Epstein-Barr virus and canine distemper virus.Together, these data demonstrate the feasibility of xenosurveillance and in doing so validated a simple and non-invasive surveillance tool that could be used to complement current biosurveillance efforts.
based prevalence studies have been done in Nigeria. ... of Health had earlier adopted population-based voluntary counselling .... value of 1) with HBV, HCV and HIV infections were excluded in the .... 27-year age group being worst affected.
AJRH Managing Editor
rate in pregnancy and the prevalence of HIV in pregnant women in labour with previously unknown status. HIV testing and .... laboratory was used to certify the kit performance before use. .... married men thereby reducing risk of HIV.
Vora, S H; Motghare, D D; Ferreira, A M; Kulkarni, M S; Vaz, F S
A cross sectional study among 450 individuals selected by strafified random sampling was carried out in rural Goa to find out the prevalence of cysticercosis and taeniasis, as well as to study the role of various factors associated with this diseases. The study participants were administered a pre-tested structured questionnaire and subsequently blood and stool samples were examined. SPSS software was used to analyze the data statistically. The sero-prevalence of cysterosis was 22.4%, which increased with age. Prevalence of taeniasis was 9.7% by stool examination. Individuals with taeniasis were thrice more likely to have cysticercosis; however no association between sero-positivity for cysterosis and pork consumption as well as religion could be established. The study confirmed a high sero-prevalence of cysticercosis in Goa underscoring the need to general awareness about good cooking habits and sanitation.
Full Text Available Photorhabdus are highly effective insect pathogenic bacteria that exist in a mutualistic relationship with Heterorhabditid nematodes. Unlike other members of the genus, Photorhabdus asymbiotica can also infect humans. Most Photorhabdus cannot replicate above 34°C, limiting their host-range to poikilothermic invertebrates. In contrast, P. asymbiotica must necessarily be able to replicate at 37°C or above. Many well-studied mammalian pathogens use the elevated temperature of their host as a signal to regulate the necessary changes in gene expression required for infection. Here we use RNA-seq, proteomics and phenotype microarrays to examine temperature dependent differences in transcription, translation and phenotype of P. asymbiotica at 28°C versus 37°C, relevant to the insect or human hosts respectively. Our findings reveal relatively few temperature dependant differences in gene expression. There is however a striking difference in metabolism at 37°C, with a significant reduction in the range of carbon and nitrogen sources that otherwise support respiration at 28°C. We propose that the key adaptation that enables P. asymbiotica to infect humans is to aggressively acquire amino acids, peptides and other nutrients from the human host, employing a so called "nutritional virulence" strategy. This would simultaneously cripple the host immune response while providing nutrients sufficient for reproduction. This might explain the severity of ulcerated lesions observed in clinical cases of Photorhabdosis. Furthermore, while P. asymbiotica can invade mammalian cells they must also resist immediate killing by humoral immunity components in serum. We observed an increase in the production of the insect Phenol-oxidase inhibitor Rhabduscin normally deployed to inhibit the melanisation immune cascade. Crucially we demonstrated this molecule also facilitates protection against killing by the alternative human complement pathway.
Krüger, Thomas; Luo, Ting; Schmidt, Hella; Shopova, Iordana; Kniemeyer, Olaf
Opportunistic human pathogenic fungi including the saprotrophic mold Aspergillus fumigatus and the human commensal Candida albicans can cause severe fungal infections in immunocompromised or critically ill patients. The first line of defense against opportunistic fungal pathogens is the innate immune system. Phagocytes such as macrophages, neutrophils and dendritic cells are an important pillar of the innate immune response and have evolved versatile defense strategies against microbial pathogens. On the other hand, human-pathogenic fungi have sophisticated virulence strategies to counteract the innate immune defense. In this context, proteomic approaches can provide deeper insights into the molecular mechanisms of the interaction of host immune cells with fungal pathogens. This is crucial for the identification of both diagnostic biomarkers for fungal infections and therapeutic targets. Studying host-fungal interactions at the protein level is a challenging endeavor, yet there are few studies that have been undertaken. This review draws attention to proteomic techniques and their application to fungal pathogens and to challenges, difficulties, and limitations that may arise in the course of simultaneous dual proteome analysis of host immune cells interacting with diverse morphotypes of fungal pathogens. On this basis, we discuss strategies to overcome these multifaceted experimental and analytical challenges including the viability of immune cells during co-cultivation, the increased and heterogeneous protein complexity of the host proteome dynamically interacting with the fungal proteome, and the demands on normalization strategies in terms of relative quantitative proteome analysis.
In, Julie G; Foulke-Abel, Jennifer; Estes, Mary K; Zachos, Nicholas C; Kovbasnjuk, Olga; Donowitz, Mark
The development of indefinitely propagating human 'mini-guts' has led to a rapid advance in gastrointestinal research related to transport physiology, developmental biology, pharmacology, and pathophysiology. These mini-guts, also called enteroids or colonoids, are derived from LGR5 + intestinal stem cells isolated from the small intestine or colon. Addition of WNT3A and other growth factors promotes stemness and results in viable, physiologically functional human intestinal or colonic cultures that develop a crypt-villus axis and can be differentiated into all intestinal epithelial cell types. The success of research using human enteroids has highlighted the limitations of using animals or in vitro, cancer-derived cell lines to model transport physiology and pathophysiology. For example, curative or preventive therapies for acute enteric infections have been limited, mostly due to the lack of a physiological human intestinal model. However, the human enteroid model enables specific functional studies of secretion and absorption in each intestinal segment as well as observations of the earliest molecular events that occur during enteric infections. This Review describes studies characterizing these human mini-guts as a physiological model to investigate intestinal transport and host-pathogen interactions.
Gorham, T J; Lee, J
Canada geese (Branta canadensis) faeces have been shown to contain pathogenic protozoa and bacteria in numerous studies over the past 15 years. Further, increases in both the Canada geese populations and their ideal habitat requirements in the United States (US) translate to a greater presence of these human pathogens in public areas, such as recreational freshwater beaches. Combining these factors, the potential health risk posed by Canada geese faeces at freshwater beaches presents an emerging public health issue that warrants further study. Here, literature concerning human pathogens in Canada geese faeces is reviewed and the potential impacts these pathogens may have on human health are discussed. Pathogens of potential concern include Campylobacter jejuni, Salmonella Typhimurium, Listeria monocytogenes, Helicobacter canadensis, Arcobacter spp., Enterohemorragic Escherichia coli pathogenic strains, Chlamydia psitacci, Cryptosporidium parvum and Giardia lamblia. Scenarios presenting potential exposure to pathogens eluted from faeces include bathers swimming in lakes, children playing with wet and dry sand impacted by geese droppings and other common recreational activities associated with public beaches. Recent recreational water-associated disease outbreaks in the US support the plausibility for some of these pathogens, including Cryptosporidium spp. and C. jejuni, to cause human illness in this setting. In view of these findings and the uncertainties associated with the real health risk posed by Canada geese faecal pathogens to users of freshwater lakes, it is recommended that beach managers use microbial source tracking and conduct a quantitative microbial risk assessment to analyse the local impact of Canada geese on microbial water quality during their decision-making process in beach and watershed management. © 2015 Blackwell Verlag GmbH.
Hwang, Jusun; Gottdenker, Nicole; Min, Mi-Sook; Lee, Hang; Chun, Myung-Sun
In this study, we evaluated the potential association between the habitat types of feral cats and the prevalence of selected infectious pathogens and health status based on a set of blood parameters. We live-trapped 72 feral cats from two different habitat types: an urban area (n = 48) and a rural agricultural area (n = 24). We compared blood values and the prevalence of feline immunodeficiency virus (FIV), feline leukaemia virus (FeLV) and haemotropic Mycoplasma infection in feral cats from the two contrasting habitats. Significant differences were observed in several blood values (haematocrit, red blood cells, blood urea nitrogen, creatinine) depending on the habitat type and/or sex of the cat. Two individuals from the urban area were seropositive for FIV (3.0%), and eight (12.1%) were positive for FeLV infection (five from an urban habitat and three from a rural habitat). Haemoplasma infection was more common. Based on molecular analysis, 38 cats (54.3%) were positive for haemoplasma, with a significantly higher infection rate in cats from rural habitats (70.8%) compared with urban cats (47.8%). Our study recorded haematological and serum biochemical values, and prevalence of selected pathogens in feral cat populations from two different habitat types. A subset of important laboratory parameters from rural cats showed values under or above the corresponding reference intervals for healthy domestic cats, suggesting potential differences in the health status of feral cats depending on the habitat type. Our findings provide information about the association between 1) blood values (haematological and serum biochemistry parameters) and 2) prevalence of selected pathogen infections and different habitat types; this may be important for veterinarians who work with feral and/or stray cats and for overall cat welfare management. © ISFM and AAFP 2015.
Pérez Pulido, Rubén; Grande Burgos, Maria José; Gálvez, Antonio; Lucas López, Rosario
Bacteriophages have attracted great attention for application in food biopreservation. Lytic bacteriophages specific for human pathogenic bacteria can be isolated from natural sources such as animal feces or industrial wastes where the target bacteria inhabit. Lytic bacteriophages have been tested in different food systems for inactivation of main food-borne pathogens including Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, Salmonella enterica, Shigella spp., Campylobacter jejuni and Cronobacter sakazkii, and also for control of spoilage bacteria. Application of lytic bacteriophages could selectively control host populations of concern without interfering with the remaining food microbiota. Bacteriophages could also be applied for inactivation of bacteria attached to food contact surfaces or grown as biofilms. Bacteriophages may receive a generally recognized as safe status based on their lack of toxicity and other detrimental effects to human health. Phage preparations specific for L. monocytogenes, E. coli O157:H7 and S. enterica serotypes have been commercialized and approved for application in foods or as part of surface decontamination protocols. Phage endolysins have a broader host specificity compared to lytic bacteriophages. Cloned endolysins could be used as natural preservatives, singly or in combination with other antimicrobials such as bacteriocins.
Noorshilawati Abdul Aziz; Umi Nadhirah Halim; Nur Suraya Abdullah
Chloroform and methanol extracts of Elaeis guineensis leaves were investigated for in vitro antibacterial activity against the human pathogenic bacteria Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Four different concentrations of both extracts consists of 50, 100, 200 and 300 mg/ ml were prepared for antibacterial activity using disc diffusion method. The results revealed that chloroform and methonal extract showed high toxicity against all bacterial strain tested. However, both extracts is more effective and exhibit better inhibiting activity against gram positive bacteria, S. aureus compared to gram negative bacteria (E. coli and P. aeruginosa). Methanol extract of Elaeis guineensis leaves shows greater inhibition zone compared to chloroform extract as phyto chemical screening revealed that this extracts contain terpenoids, tannins and saponin. The highest antibacterial activity was exhibited by 300 mg/ ml methanolic extracts against S. aureus which inhibited 10.67 ± 0.33 mm of the diameter zone. Followed by 200 mg/ ml methanolic extracts and 300 mg/ ml chloroform extracts against S. aureus which inhibited 9.17 ± 0.17 mm and 8.33 ± 1.67 mm respectively. This result revealed the potentials of Elaeis guineensis as antibacterial agent in combating infections from human pathogenic bacteria. However, further studies, including identification and purification of the active compounds, will need to be pursued. (author)
Chandra L Shrestha
Full Text Available Members of the Burkholderia cepacia complex are virulent, multi-drug resistant pathogens that survive and replicate intracellularly in patients with cystic fibrosis (CF. We have discovered that B. cenocepacia cannot be cleared from CF macrophages due to defective autophagy, causing continued systemic inflammation and infection. Defective autophagy in CF is mediated through constitutive reactive oxygen species (ROS activation of transglutaminase-2 (TG2, which causes the sequestration (accumulation of essential autophagy initiating proteins. Cysteamine is a TG2 inhibitor and proteostasis regulator with the potential to restore autophagy. Therefore, we sought to examine the impact of cysteamine on CF macrophage autophagy and bacterial killing. Human peripheral blood monocyte-derived macrophages (MDMs and alveolar macrophages were isolated from CF and non-CF donors. Macrophages were infected with clinical isolates of relevant CF pathogens. Cysteamine caused direct bacterial growth killing of live B. cenocepacia, B. multivorans, P. aeruginosa and MRSA in the absence of cells. Additionally, B. cenocepacia, B. multivorans, and P. aeruginosa invasion were significantly decreased in CF MDMs treated with cysteamine. Finally, cysteamine decreased TG2, p62, and beclin-1 accumulation in CF, leading to increased Burkholderia uptake into autophagosomes, increased macrophage CFTR expression, and decreased ROS and IL-1β production. Cysteamine has direct anti-bacterial growth killing and improves human CF macrophage autophagy resulting in increased macrophage-mediated bacterial clearance, decreased inflammation, and reduced constitutive ROS production. Thus, cysteamine may be an effective adjunct to antibiotic regimens in CF.
Full Text Available AbstractToll-Like Receptor (TLR signaling represents one of the best studied pathways to implement defense mechanisms against invading microbes in humans as well as in animals. TLRs respond to specific microbial ligands and to danger signals produced by the host during infection, and initiate downstream cascades that activate both innate and adaptive immunity. TLRs are expressed by professional immune cells and by the large majority of non-hematopoietic cells, including epithelial cells. In epithelial tissues, TLR functions are particularly important because these sites are constantly exposed to microorganisms, due to their location at the host interface with the environment. While at these sites, specific defense mechanisms and inflammatory responses are initiated via TLR signaling against pathogens, suppression or lack of TLR activation is also observed in response to the commensal microbiota. The mechanisms by which TLR signaling is regulated in mucosal epithelial cells include differential expression and levels of TLRs (and their signaling partners, their cellular localization and positioning within the tissue in a fashion that favors responses to pathogens while dampening responses to commensals and maintaining tissue homeostasis in physiologic conditions. In this review, the expression and activation of TLRs in mucosal epithelial cells of several sites of the human body are examined. Specifically, the oral cavity, the ear canal and eye, the airways, the gut and the reproductive tract are discussed, along with how site-specific host defense mechanisms are implemented via TLR signaling.
Abalkhil, Tarad Abdulaziz; Alharbi, Sulaiman Ali; Salmen, Saleh Hussein; Wainwright, Milton
Green synthesis is an attractive and eco-friendly approach to generate potent antibacterial silver nanoparticles (Ag-NPs). Such particles have long been used to fight bacteria and represent a promising tool to overcome the emergence of antibiotic-resistant bacteria. In this study, green synthesis of Ag-NPs was attempted using plant extracts of Aloe vera, Portulaca oleracea and Cynodon dactylon. The identity and size of Ag-NPs was characterized by ultraviolet–visible spectrophotometer and scanning electron microscopy. Monodispersed Ag-NPs were produced with a range of different sizes based on the plant extract used. The bactericidal activity of Ag-NPs against a number of human pathogenic bacteria was determined using the disc diffusion method. The results showed that Gram positive bacteria were more susceptible than Gram negative ones to these antibacterial agents. The minimum inhibitory concentration was determined using the 96- well plate method. Finally, the mechanism by which Ag-NPs affect bacteria was investigated by SEM analysis. Bacteria treated with Ag-NPs were seen to undergo shrinkage and to lose their viability. This study provides evidence for a cheap and effective method for synthesizing potent bactericidal Ag-NPs and demonstrates their effectiveness against human pathogenic bacteria
Full Text Available Streptococcus suis, a major porcine pathogen, has been receiving growing attention not only for its role in severe and increasingly reported infections in humans, but also for its involvement in drug resistance. Recent studies and the analysis of sequenced genomes have been providing important insights into the S. suis resistome, and have resulted in the identification of resistance determinants for tetracyclines, macrolides, aminoglycosides, chloramphenicol, antifolate drugs, streptothricin, and cadmium salts. Resistance gene-carrying genetic elements described so far include integrative and conjugative elements, transposons, genomic islands, phages, and chimeric elements. Some of these elements are similar to those reported in major streptococcal pathogens such as Streptococcus pyogenes, Streptococcus pneumoniae, and Streptococcus agalactiae and share the same chromosomal insertion sites. The available information strongly suggests that S. suis is an important antibiotic resistance reservoir that can contribute to the spread of resistance genes to the above-mentioned streptococci. S. suis is thus a paradigmatic example of possible intersections between animal and human resistomes.
Full Text Available Enteric bacterial human pathogens, i.e., Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Klebsiella pneumoniae, are the major cause of diarrheal infections in children and adults. Their structure badly affects the human immune system. It is important to explore new antibacterial agents instead of antibiotics for treatment. This project is an attempt to explain how gold nanoparticles affect these bacteria. We investigated the important role of the mean particle size, and the inhibition of a bacterium is dose-dependent. Ultra Violet (UV-visible spectroscopy revealed the size of chemically synthesized gold nanoparticle as 6–40 nm. Atomic force microscopy (AFM analysis confirmed the size and X-ray diffractometry (XRD analysis determined the polycrystalline nature of gold nanoparticles. The present findings explained how gold nanoparticles lyse Gram-negative and Gram-positive bacteria.
Thøgersen, Juliane Charlotte
modeling to uncover how human pathogens adapt to the human host. Pseudomonas aeruginosa infections in cystic fibrosis patients are used as a model system for under-‐ standing these adaptation processes. The exploratory systems biology approach facilitates identification of important phenotypes...... by classical molecular biology approaches where genes and reactions typically are investigated in a one to one relationship. This thesis is an example of how mathematical approaches and modeling can facilitate new biologi-‐ cal understanding and provide new surprising ideas to important biological processes....... and metabolic pathways that are necessary or related to establishment of chronic infections. Archetypal analysis showed to be successful in extracting relevant phenotypes from global gene expression da-‐ ta. Furthermore, genome-‐scale metabolic modeling showed to be useful in connecting the genotype...
Mendoza-Olazarán, Soraya; Garcia-Mazcorro, José F; Morfín-Otero, Rayo; Villarreal-Treviño, Licet; Camacho-Ortiz, Adrián; Rodríguez-Noriega, Eduardo; Bocanegra-Ibarias, Paola; Maldonado-Garza, Héctor J; Dowd, Scot E; Garza-González, Elvira
Herein, we report the draft-genome sequences and annotation of two opportunistic pathogenic strains of Staphylococcus cohnii isolated from humans. One strain (SC-57) was isolated from blood from a male patient in May 2006 and the other (SC-532) from a catheter from a male patient in June 2006. Similar to other genomes of Staphylococcus species, most genes (42%) of both strains are involved in metabolism of amino acids and derivatives, carbohydrates and proteins. Eighty (4%) genes are involved in virulence, disease, and defense and both species show phenotypic low biofilm production and evidence of increased antibiotic resistance associated to biofilm production. From both isolates, a new Staphylococcal Cassette Chromosome mec was detected: mec class A, ccr type 1. This is the first report of whole genome sequences of opportunistic S. cohnii isolated from human patients.
Søndergaard, Jonas Nørskov
for society. Consequently there is a pressing need to search for new treatment strategies. Nowadays it is known that HIV-1 and Mtb have acquired the ability to escape the removal from the body by exploiting the immune system for their own benefits. Dendritic cells (DCs) determine the way the immune response......Latent infections with the human pathogenic microorganisms Mycobacterium tuberculosis (Mtb) and the human immunodeficiency virus (HIV) are creating some of the most devastating pandemics to date, with great impact on the infected people’s lives, their expected lifetime, as well as general costs...... unfolds by signaling other immune cells how to respond. An early deregulation of the DCs may therefore propagate into detrimental effects in later stages of the immune response, and may permit HIV-1 and Mtb to become latent. Hence, understanding the way HIV-1 and Mtb interacts with DCs could lead to novel...
Miller, WG; Wang, G; Binnewies, Tim Terence
Campylobacter lari is a member of the epsilon subdivision of the Proteobacteria and is part of the thermotolerant Campylobacter group, a clade that includes the human pathogen C. jejuni. Here we present the complete genome sequence of the human clinical isolate, C. lari RM2100. The genome of strain...... RM2100 is approximately 1.53 Mb and includes the 46 kb megaplasmid pCL2100. Also present within the strain RM2100 genome is a 36 kb putative prophage, termed CLIE1, which is similar to CJIE4, a putative prophage present within the C. jejuni RM1221 genome. Nearly all (90%) of the gene content...... in strain RM2100 is similar to genes present in the genomes of other characterized thermotolerant campylobacters. However, several genes involved in amino acid biosynthesis and energy metabolism, identified previously in other Campylobacter genomes, are absent from the C. lari RM2100 genome. Therefore, C...
Vazquez, Miguel; Pons, Tirso; Brunak, Søren
forest approach. To understand the biological mechanisms causative of human diseases and cancer, information from pertinent reference knowledgebases and the literature is automatically mined, digested and homogenized. Variants are visualized in their structural contexts and residues affecting catalytic...... is often scattered across different sources, which makes the integrative analysis complex and laborious. wKinMut-2 constitutes a solution to facilitate the interpretation of the consequences of human protein kinase variation. Nine methods predict their pathogenicity, including a kinase-specific random...... and drug-binding are identified. Known protein-protein interactions are reported. Altogether, this information is intended to assist the generation of new working hypothesis to be corroborated with ulterior experimental work. The wKinMut-2 system, along with a user manual and examples is freely accessible...
Prevalence of Salmonella enterica, Listeria monocytogenes, and pathogenic Escherichia coli in bulk tank milk and milk filters from US dairy operations in the National Animal Health Monitoring System Dairy 2014 study.
Sonnier, Jakeitha L; Karns, Jeffrey S; Lombard, Jason E; Kopral, Christine A; Haley, Bradd J; Kim, Seon-Woo; Van Kessel, Jo Ann S
The dairy farm environment is a well-documented reservoir for zoonotic pathogens such as Salmonella enterica, Shiga-toxigenic Escherichia coli, and Listeria monocytogenes, and humans may be exposed to these pathogens via consumption of unpasteurized milk and dairy products. As part of the National Animal Health Monitoring System Dairy 2014 study, bulk tank milk (BTM, n = 234) and milk filters (n = 254) were collected from a total of 234 dairy operations in 17 major dairy states and analyzed for the presence of these pathogens. The invA gene was detected in samples from 18.5% of operations and Salmonella enterica was isolated from 18.0% of operations. Salmonella Dublin was detected in 0.7% of operations. Sixteen Salmonella serotypes were isolated, and the most common serotypes were Cerro, Montevideo, and Newport. Representative Salmonella isolates (n = 137) were tested against a panel of 14 antimicrobials. Most (85%) were pansusceptible; the remaining were resistant to 1 to 9 antimicrobials, and within the resistant strains the most common profile was resistance to ampicillin/clavulanic acid, ampicillin, cefoxitin, ceftiofur, ceftriaxone, chloramphenicol, streptomycin, sulfisoxazole, and tetracycline. Listeria spp. were isolated from 19.9% of operations, and L. monocytogenes was isolated from 3.0% of operations. Serogroups 1/2a and 1/2b were the most common, followed by 4b and 4a. One or more E. coli virulence genes were detected in the BTM from 30.5% of operations and in the filters from 75.3% of operations. A combination of stx 2 , eaeA, and γ-tir genes was detected in the BTM from 0.5% of operations and in the filters from 6.6% of operations. The results of this study indicate an appreciable prevalence of bacterial pathogens in BTM and filters, including serovars known to infect humans. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Full Text Available Clostridium difficile causes antibiotic-associated diarrhoea and pseudomembranous colitis. The main virulence factors of C. difficile are the toxins A (TcdA and B (TcdB. A third toxin, called binary toxin (CDT, can be detected in 17% to 23% of strains, but its role in human disease has not been clearly defined. We report six independent cases of patients with diarrhoea suspected of having C. difficile infection due to strains from toxinotype XI/PCR ribotype 033 or 033-like, an unusual toxinotype/PCR ribotype positive for CDT but negative for TcdA and TcdB. Four patients were considered truly infected by clinicians and were specifically treated with oral metronidazole. One of the cases was identified during a prevalence study of A−B−CDT+ strains. In this study, we screened a French collection of 220 nontoxigenic strains and found only one (0.5% toxinotype XI/PCR ribotype 033 or 033-like strain. The description of such strains raises the question of the role of binary toxin as a virulence factor and could have implications for laboratory diagnostics that currently rarely include testing for binary toxin.
Ishii, S.; Yan, T.; Shively, D.A.; Byappanahalli, M.N.; Whitman, R.L.; Sadowsky, M.J.
Cladophora glomerata, a macrophytic green alga, is commonly found in the Great Lakes, and significant accumulations occur along shorelines during the summer months. Recently, Cladophora has been shown to harbor high densities of the fecal indicator bacteria Escherichia coli and enterococci. Cladophora may also harbor human pathogens; however, until now, no studies to address this question have been performed. In the present study, we determined whether attachedCladophora, obtained from the Lake Michigan and Burns Ditch (Little Calumet River, Indiana) sides of a breakwater during the summers of 2004 and 2005, harbored the bacterial pathogens Shiga toxin-producing Escherichia coli (STEC),Salmonella, Shigella, and Campylobacter. The presence of potential pathogens and numbers of organisms were determined by using cultural methods and by using conventional PCR, most-probable-number PCR (MPN-PCR), and quantitative PCR (QPCR) performed with genus- and toxin-specific primers and probes. WhileShigella and STEC were detected in 100% and 25%, respectively, of the algal samples obtained near Burns Ditch in 2004, the same pathogens were not detected in samples collected in 2005. MPN-PCR and QPCR allowed enumeration of Salmonella in 40 to 80% of the ditch- and lakeside samples, respectively, and the densities were up to 1.6 × 103 cells per g Cladophora. Similarly, these PCR methods allowed enumeration of up to 5.4 × 102 Campylobacter cells/gCladophora in 60 to 100% of lake- and ditchside samples. The Campylobacterdensities were significantly higher (P fingerprint analyses indicated that genotypically identical Salmonella isolates were associated with geographically and temporally distinct Cladophora samples. However, Campylobacter isolates were genetically diverse. Since animal hosts are thought to be the primary habitat forCampylobacter and Salmonella species, our results suggest that Cladophora is a likely secondary habitat for pathogenic
Ishii, Satoshi; Yan, Tao; Shively, Dawn A.; Byappanahalli, Muruleedhara N.; Whitman, Richard L.; Sadowsky, Michael J.
Cladophora glomerata, a macrophytic green alga, is commonly found in the Great Lakes, and significant accumulations occur along shorelines during the summer months. Recently, Cladophora has been shown to harbor high densities of the fecal indicator bacteria Escherichia coli and enterococci. Cladophora may also harbor human pathogens; however, until now, no studies to address this question have been performed. In the present study, we determined whether attached Cladophora, obtained from the Lake Michigan and Burns Ditch (Little Calumet River, Indiana) sides of a breakwater during the summers of 2004 and 2005, harbored the bacterial pathogens Shiga toxin-producing Escherichia coli (STEC), Salmonella, Shigella, and Campylobacter. The presence of potential pathogens and numbers of organisms were determined by using cultural methods and by using conventional PCR, most-probable-number PCR (MPN-PCR), and quantitative PCR (QPCR) performed with genus- and toxin-specific primers and probes. While Shigella and STEC were detected in 100% and 25%, respectively, of the algal samples obtained near Burns Ditch in 2004, the same pathogens were not detected in samples collected in 2005. MPN-PCR and QPCR allowed enumeration of Salmonella in 40 to 80% of the ditch- and lakeside samples, respectively, and the densities were up to 1.6 × 103 cells per g Cladophora. Similarly, these PCR methods allowed enumeration of up to 5.4 × 102 Campylobacter cells/g Cladophora in 60 to 100% of lake- and ditchside samples. The Campylobacter densities were significantly higher (P Cladophora samples than in the ditchside Cladophora samples. DNA fingerprint analyses indicated that genotypically identical Salmonella isolates were associated with geographically and temporally distinct Cladophora samples. However, Campylobacter isolates were genetically diverse. Since animal hosts are thought to be the primary habitat for Campylobacter and Salmonella species, our results suggest that Cladophora is a
Ishii, Satoshi; Yan, Tao; Shively, Dawn A; Byappanahalli, Muruleedhara N; Whitman, Richard L; Sadowsky, Michael J
Cladophora glomerata, a macrophytic green alga, is commonly found in the Great Lakes, and significant accumulations occur along shorelines during the summer months. Recently, Cladophora has been shown to harbor high densities of the fecal indicator bacteria Escherichia coli and enterococci. Cladophora may also harbor human pathogens; however, until now, no studies to address this question have been performed. In the present study, we determined whether attached Cladophora, obtained from the Lake Michigan and Burns Ditch (Little Calumet River, Indiana) sides of a breakwater during the summers of 2004 and 2005, harbored the bacterial pathogens Shiga toxin-producing Escherichia coli (STEC), Salmonella, Shigella, and Campylobacter. The presence of potential pathogens and numbers of organisms were determined by using cultural methods and by using conventional PCR, most-probable-number PCR (MPN-PCR), and quantitative PCR (QPCR) performed with genus- and toxin-specific primers and probes. While Shigella and STEC were detected in 100% and 25%, respectively, of the algal samples obtained near Burns Ditch in 2004, the same pathogens were not detected in samples collected in 2005. MPN-PCR and QPCR allowed enumeration of Salmonella in 40 to 80% of the ditch- and lakeside samples, respectively, and the densities were up to 1.6 x 10(3) cells per g Cladophora. Similarly, these PCR methods allowed enumeration of up to 5.4 x 10(2) Campylobacter cells/g Cladophora in 60 to 100% of lake- and ditchside samples. The Campylobacter densities were significantly higher (P Cladophora samples than in the ditchside Cladophora samples. DNA fingerprint analyses indicated that genotypically identical Salmonella isolates were associated with geographically and temporally distinct Cladophora samples. However, Campylobacter isolates were genetically diverse. Since animal hosts are thought to be the primary habitat for Campylobacter and Salmonella species, our results suggest that Cladophora is a
Regina G. Kleespies
Full Text Available About 20,550 larvae, pupae and adults of the codling moth, Cydia pomonella L., were diagnosed for pathogens during long-term investigations (1955–2012 at the Institute for Biological Control in Darmstadt, Germany. The prevailing entomopathogens diagnosed in these studies were insect pathogenic fungi, especially Beauveria bassiana and Isaria farinosa, the microsporidium, Nosema carpocapsae, the Cydia pomonella granulovirus (CpGV, as well as mostly undetermined bacteria. While the CpGV was observed exclusively in larvae and pupae from laboratory colonies or from field experiments with this virus, entomopathogenic fungi were most frequently diagnosed in last instars in autumn and in diapausing larvae and pupae in spring. B. bassiana was identified as the major fungal pathogen, causing larval prevalences of 0.9% to 100% (mean, about 32%. During prognostic long-term studies in larvae and adults of C. pomonella, N. carpocapsae was diagnosed in codling moth populations from various locations in Germany. The mean prevalence generally ranged between 20% and 50%. Experiments revealed that the fecundity and fertility of microsporidia-infected female adults were significantly reduced compared to healthy ones. The results underpin the importance of naturally occurring microbial antagonists and represent a base for further ecological studies on developing new or additional biological and integrated control strategies.
Conclusion: Results indicated that dental caries prevalence among school children in Qatar has reached critical levels, and is influenced by socio-demographic factors. The mean decayed, missing, and filled teeth values obtained in this study were the second highest detected in the Eastern Mediterranean region.
Genna E Davies
Full Text Available The fungal genus Trichosporon contains emerging opportunistic pathogens of humans, and is the third most commonly isolated non-candidal yeast from humans. Trichosporon asahii and T. asteroides are the most important species causing disseminated disease in immunocompromised patients, while inhalation of T. asahii spores is the most important cause of summer-type hypersensitivity pneumonitis in healthy individuals. Trichosporonosis is misdiagnosed as candidiasis or cryptococcosis due to a lack of awareness and the ambiguity of diagnostic tests for these pathogens. In this study, hybridoma technology was used to produce two murine monoclonal antibodies (MAbs, CA7 and TH1, for detection and differentiation of Trichosporon from other human pathogenic yeasts and moulds. The MAbs react with extracellular antigens from T. asahii and T. asteroides, but do not recognise other related Trichosporon spp., or unrelated pathogenic yeasts and moulds including Candida, Cryptococcus, Aspergillus, Fusarium, and Scedosporium spp., or the etiologic agents of mucormycosis. Immunofluorescence and Western blotting studies show that MAb CA7, an immunoglobulin G1 (IgG1, binds to a major 60 kDa glycoprotein antigen produced on the surface of hyphae, while TH1, an immunoglobulin M (IgM, binds to an antigen produced on the surface of conidia. The MAbs were used in combination with a standard mycological growth medium (Sabouraud Dextrose Agar to develop an enzyme-linked immunosorbent assay (ELISA for differentiation of T. asahii from Candida albicans and Cryptococcus neoformans in single and mixed species cultures. The MAbs represent a major advance in the identification of T. asahii and T. asteroides using standard mycological identification methods.
Full Text Available Abstract Coupled physical-biological models are capable of linking the complex interactions between environmental factors and physical hydrodynamics to simulate the growth, toxicity and transport of infectious pathogens and harmful algal blooms (HABs. Such simulations can be used to assess and predict the impact of pathogens and HABs on human health. Given the widespread and increasing reliance of coastal communities on aquatic systems for drinking water, seafood and recreation, such predictions are critical for making informed resource management decisions. Here we identify three challenges to making this connection between pathogens/HABs and human health: predicting concentrations and toxicity; identifying the spatial and temporal scales of population and ecosystem interactions; and applying the understanding of population dynamics of pathogens/HABs to management strategies. We elaborate on the need to meet each of these challenges, describe how modeling approaches can be used and discuss strategies for moving forward in addressing these challenges.
Cryptosporidium is said to cause diarrhoea in HIV / AIDS patients. The study was done to determine the prevalence of cryptosporidiosis in Lagos. Stool samples were collected from 193 HIV positive and 200 HIV negative (control) patients presenting with diarrhoea at LUTH. The patient or a close relative filled a ...
The study which was conducted between March and June 2015 also investigated the sero prevalence of Onchocerca volvulus using onchocerciasis IgG4 RDT. Data were analysed using SPSS 20 software. Demographic information revealed that 43.3% (939/2,169) were males while 56.7% (1,230/2,169) were females.
Marga G A Goris
Full Text Available BACKGROUND: Leptospirosis is caused by pathogenic spirochetes of the genus Leptospira. The bacteria enter the human body via abraded skin or mucous membranes and may disseminate throughout. In general the clinical picture is mild but some patients develop rapidly progressive, severe disease with a high case fatality rate. Not much is known about the innate immune response to leptospires during haematogenous dissemination. Previous work showed that a human THP-1 cell line recognized heat-killed leptospires and leptospiral LPS through TLR2 instead of TLR4. The LPS of virulent leptospires displayed a lower potency to trigger TNF production by THP-1 cells compared to LPS of non-virulent leptospires. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the host response and killing of virulent and non-virulent Leptospira of different serovars by human THP-1 cells, human PBMC's and human whole blood. Virulence of each leptospiral strain was tested in a well accepted standard guinea pig model. Virulent leptospires displayed complement resistance in human serum and whole blood while in-vitro attenuated non-virulent leptospires were rapidly killed in a complement dependent manner. In vitro stimulation of THP-1 and PBMC's with heat-killed and living leptospires showed differential serovar and cell type dependence of cytokine induction. However, at low, physiological, leptospiral dose, living virulent complement resistant strains were consistently more potent in whole blood stimulations than the corresponding non-virulent complement sensitive strains. At higher dose living virulent and non-virulent leptospires were equipotent in whole blood. Inhibition of different TLRs indicated that both TLR2 and TLR4 as well as TLR5 play a role in the whole blood cytokine response to living leptospires. CONCLUSIONS/SIGNIFICANCE: Thus, in a minimally altered system as human whole blood, highly virulent Leptospira are potent inducers of the cytokine response.
Full Text Available Bats are reservoir hosts of many important viruses that cause substantial disease in humans, including coronaviruses, filoviruses, lyssaviruses, and henipaviruses. Other than the lyssaviruses, they do not appear to cause disease in the reservoir bats, thus an explanation for the dichotomous outcomes of infections of humans and bat reservoirs remains to be determined. Bats appear to have a few unusual features that may account for these differences, including evidence of constitutive interferon (IFN activation and greater combinatorial diversity in immunoglobulin genes that do not undergo substantial affinity maturation. We propose these features may, in part, account for why bats can host these viruses without disease and how they may contribute to the highly pathogenic nature of bat-borne viruses after spillover into humans. Because of the constitutive IFN activity, bat-borne viruses may be shed at low levels from bat cells. With large naive antibody repertoires, bats may control the limited virus replication without the need for rapid affinity maturation, and this may explain why bats typically have low antibody titers to viruses. However, because bat viruses have evolved in high IFN environments, they have enhanced countermeasures against the IFN response. Thus, upon infection of human cells, where the IFN response is not constitutive, the viruses overwhelm the IFN response, leading to abundant virus replication and pathology.
Luisa Z Moreno
Full Text Available Leptospira interrogans serovar Canicola is one of the most important pathogenic serovars for the maintenance of urban leptospirosis. Even though it is considered highly adapted to dogs, serovar Canicola infection has already been described in other animals and even a few human cases. Here, we present the genomic characterisation of two Brazilian L. interrogans serovar Canicola strains isolated from slaughtered sows (L0-3 and L0-4 and their comparison with human strain Fiocruz LV133. It was observed that the porcine serovar Canicola strains present the genetic machinery to cause human infection and, therefore, represent a higher risk to public health. Both human and porcine serovar Canicola isolates also presented sequences with high identity to the Chinese serovar Canicola published plasmids pGui1 and pGui2. The plasmids identification in the Brazilian and Chinese serovar Canicola strains suggest that extra-chromosomal elements are one more feature of this serovar that was previously unnoticed.
Svahn, Malene F; Faber, Mette Tuxen; Christensen, Jane
The role of human papillomavirus (HPV) in the pathogenesis of ovarian cancer is controversial, and conflicting results have been published. We conducted a systematic review and meta-analysis to estimate the prevalence of HPV in epithelial ovarian cancer tissue....
Muller, Shabani K; Assenga, Justine A; Matemba, Lucas E; Misinzo, Gerald; Kazwala, Rudovick R
Leptospirosis is a neglected zoonotic disease of worldwide public health importance. The disease affects humans, domestic animals and wildlife. However, leptospirosis is challenging in its diagnosis in humans. Culture technique, which is time consuming, is not recommended for clinical diagnosis. For these reasons, serological and molecular techniques remain the test of choice. The major objective of this study was to explore the genetic characteristic of Leptospira species which are prevalent among agro-pastoralists living in Katavi-Rukwa Ecosystem, Tanzania. A cross-sectional epidemiological study was carried out in the Katavi-Region South-west, Tanzania between August, 2013 and November, 2014. A total of 267 participants were randomly recruited for the study. Microscopic agglutination test (MAT) was used to detect antibody against six Leptospira antigens including local serogroups Icterohaemorrhagiae, Ballum, Grippotyphosa, Sejroe and reference serogroups Hebdomadis, and Australis. Samples with MAT titers ≥ 1:160 were scored as positive, samples with MAT titers ranging from 1:20 to 1:80 were scored as exposed to Leptospira, and absence of agglutination titers was scored as negative. All MAT positive samples, including the low titre samples were subjected to PCR using the respective 16S rRNA primers for the pathogenic and non-pathogenic species. Out of 267 samples tested, 80 (29.9 %) were positive with MAT. The major circulating leptospiral serogroups were Sejroe (15.7 %,), Icterohaemorrhagiae (8.9 %), Grippotyphosa (4.8 %), Hebdomadis (3.37 %), Australis (1.49 %) and Ballum (1.19 %). By using PCR, 33 (15.7 %) out of 210 samples were pathogenic Leptospira while no saprophytic Leptospira spp. was detected. Partial 16S rRNA gene sequences of Leptospira species which were obtained from this study were submitted to GenBank and acquired accession numbers KP313246 and KP313247. Phylogenetic analysis of the nucleotide sequences revealed that species
Khan, Sher Bahadar; Zou, Geng; Xiao, Ran; Cheng, Yuting; Rehman, Zia Ur; Ali, Sher; Memon, Atta Muhammad; Fahad, Shah; Ahmad, Irshad; Zhou, Rui
Shiga toxin Escherichia coli (STEC) O157:H7 is an important zoonotic food borne pathogen causing gastroenteritis that may lead to life threatening hemorragic colitis (HC) and hemorrhagic uremic syndrome (HUS). 325 meat and tissue samples were tested for enumeration of O157:H7 strains using most probable number (MPN)-PCR targeting their specific genes flicH7 and rfbO157 followed by isolation, sereotyping and pathogenicity testing. The overall prevalence of O157:H7 was 41.3% (134/325) along the production and supply chain of pork (PSCP), being higher in supply chain (59%, 118/200) as compared to pig farms (12.8%, 16/125). Along the PSCP, the highest prevalence was found in slaughter houses (86.25%, 69/80) followed by wet- (53.3%, 32/60) and super-markets (28.3%, 17/60). The MPN values ranged from 3 to 1100 MPN/g in overall positive samples, being higher in slaughter houses followed by wet and super markets. Except from intestine and meat samples of slaughter house, the MPN was found higher in summer as compared to winter samples. Eight STEC O157:H7 isolated from meat and liver samples were tested in Balb/C mice for pathogenicity. After development of clinical signs and symptoms, 50-83.3% mortality was produced in the infected mice. Histopathological investigations revealed visible necrosis of intestinal epithelial cells, shedding of cellular debris in the intestine, while in the kidney, necrosis of renal cortical portion of tubular epithelial cells was observed. STEC O157:H7 is prevalent along PSCP around Hubei of China in different proportions being alarmingly higher in supply chain and markets which is a matter of concern for public health. Copyright © 2017. Published by Elsevier Ltd.
Chiriboga, Jorge; Barragan, Verónica; Arroyo, Gabriela; Sosa, Andrea; Birdsell, Dawn N; España, Karool; Mora, Ana; Espín, Emilia; Mejía, María Eugenia; Morales, Melba; Pinargote, Carmina; Gonzalez, Manuel; Hartskeerl, Rudy; Keim, Paul; Bretas, Gustavo; Eisenberg, Joseph N S; Trueba, Gabriel
Leptospira spp., which comprise 3 clusters (pathogenic, saprophytic, and intermediate) that vary in pathogenicity, infect >1 million persons worldwide each year. The disease burden of the intermediate leptospires is unclear. To increase knowledge of this cluster, we used new molecular approaches to characterize Leptospira spp. in 464 samples from febrile patients in rural, semiurban, and urban communities in Ecuador; in 20 samples from nonfebrile persons in the rural community; and in 206 samples from animals in the semiurban community. We observed a higher percentage of leptospiral DNA-positive samples from febrile persons in rural (64%) versus urban (21%) and semiurban (25%) communities; no leptospires were detected in nonfebrile persons. The percentage of intermediate cluster strains in humans (96%) was higher than that of pathogenic cluster strains (4%); strains in animal samples belonged to intermediate (49%) and pathogenic (51%) clusters. Intermediate cluster strains may be causing a substantial amount of fever in coastal Ecuador.
Michelle D Leach
Full Text Available Eukaryotic cells have evolved mechanisms to sense and adapt to dynamic environmental changes. Adaptation to thermal insults, in particular, is essential for their survival. The major fungal pathogen of humans, Candida albicans, is obligately associated with warm-blooded animals and hence occupies thermally buffered niches. Yet during its evolution in the host it has retained a bona fide heat shock response whilst other stress responses have diverged significantly. Furthermore the heat shock response is essential for the virulence of C. albicans. With a view to understanding the relevance of this response to infection we have explored the dynamic regulation of thermal adaptation using an integrative systems biology approach. Our mathematical model of thermal regulation, which has been validated experimentally in C. albicans, describes the dynamic autoregulation of the heat shock transcription factor Hsf1 and the essential chaperone protein Hsp90. We have used this model to show that the thermal adaptation system displays perfect adaptation, that it retains a transient molecular memory, and that Hsf1 is activated during thermal transitions that mimic fever. In addition to providing explanations for the evolutionary conservation of the heat shock response in this pathogen and the relevant of this response to infection, our model provides a platform for the analysis of thermal adaptation in other eukaryotic cells.
Máté, Gábor; Kovács, Dominika; Gazdag, Zoltán; Pesti, Miklós; Szántó, Árpád
The present study investigated the linalool (Lol)-induced effects in acute toxicity tests in the human pathogen Candida albicans (C. albicans). Lol treatments induced reduced germ tube formation of the pathogen, which plays a crucial role in the virulence. In comparison with the untreated control, the exposure of 107 cells ml -1 to 0.7 mM or 1.4 mM Lol for one hour induced 20% and 30% decrements, respectively, in the colony-forming ability. At the same time, these treatments caused dose-dependent decrease in the levels of superoxide anion radical and total reactive oxygen species, while there was 1.5 and 1.8-fold increases in the concentrations of peroxides and lipid peroxides, respectively, indicating oxidative stress induction in the presence of Lol. Lol treatments resulted in different adaptive modifications of the antioxidant system. In 0.7 mM-treated cells, decreased specific activities of superoxide dismutase and catalase were detected, while exposure to 1.4 mM Lol resulted in the up-regulation of catalase, glutathione reductase and glutathione peroxidases.
Han Cong; Wang Qi; Dong Lei; Sun Haifang; Peng Shuying; Chen Jing; Yang Yiming; Yue Jianmin; Shen Xu; Jiang Hualiang
Helicobacter pylori is a gram-negative pathogenic bacterium, which is associated with peptic ulcer disease and gastric cancer. It is urgent to discover novel drug targets for appropriate antimicrobial agents against this human pathogen. In bacteria, peptide deformylase (PDF) catalyzes the removal of a formyl group from the N-termini of nascent polypeptides. Due to its essentiality and absence in mammalian cells, PDF has been considered as an attractive target for the discovery of novel antibiotics. In this work, a new PDF gene (def) from H. pylori strain SS1 was cloned, expressed, and purified in Escherichia coli system. Sequence alignment shows that H. pylori PDF (HpPDF) shares about 40% identity to E. coli PDF (EcPDF). The enzymatic properties of HpPDF demonstrate its relatively high activity toward formyl-Met-Ala-Ser, with K cat of 3.4 s -1 , K m of 1.7 mM, and K cat /K m of 2000 M -1 s -1 . HpPDF enzyme appears to be fully active at pH between 8.0 and 9.0, and temperature 50 deg. C. The enzyme activity of Co 2+ -containing HpPDF is apparently higher than that of Zn 2+ -containing HpPDF. This present work thereby supplies a potential platform that facilitates the discovery of novel HpPDF inhibitors and further of possible antimicrobial agents against H. pylori
Han, Cong; Wang, Qi; Dong, Lei; Sun, Haifang; Peng, Shuying; Chen, Jing; Yang, Yiming; Yue, Jianmin; Shen, Xu; Jiang, Hualiang
Helicobacter pylori is a gram-negative pathogenic bacterium, which is associated with peptic ulcer disease and gastric cancer. It is urgent to discover novel drug targets for appropriate antimicrobial agents against this human pathogen. In bacteria, peptide deformylase (PDF) catalyzes the removal of a formyl group from the N-termini of nascent polypeptides. Due to its essentiality and absence in mammalian cells, PDF has been considered as an attractive target for the discovery of novel antibiotics. In this work, a new PDF gene (def) from H. pylori strain SS1 was cloned, expressed, and purified in Escherichia coli system. Sequence alignment shows that H. pylori PDF (HpPDF) shares about 40% identity to E. coli PDF (EcPDF). The enzymatic properties of HpPDF demonstrate its relatively high activity toward formyl-Met-Ala-Ser, with K(cat) of 3.4s(-1), K(m) of 1.7 mM, and K(cat) / K(m) of 2000M(-1)s(-1). HpPDF enzyme appears to be fully active at pH between 8.0 and 9.0, and temperature 50 degrees C. The enzyme activity of Co(2+)-containing HpPDF is apparently higher than that of Zn(2+)-containing HpPDF. This present work thereby supplies a potential platform that facilitates the discovery of novel HpPDF inhibitors and further of possible antimicrobial agents against H. pylori.
Full Text Available New molecular identification techniques and the increased number of patients with various immune defects or underlying conditions lead to the emergence and/or the description of novel species of human and animal fungal opportunistic pathogens. Antifungal susceptibility provides important information for ecological, epidemiological and therapeutic issues. The aim of this study was to assess the potential risk of the various species based on their antifungal drug resistance, keeping in mind the methodological limitations. Antifungal susceptibility profiles to the five classes of antifungal drugs (polyens, azoles, echinocandins, allylamines and antimetabolites were determined for 1698 yeast reference strains belonging to 992 species (634 Ascomycetes and 358 Basidiomycetes. Interestingly, geometric mean minimum inhibitory concentrations (MICs of all antifungal drugs tested were significantly higher for Basidiomycetes compared to Ascomycetes (p<0.001. Twenty four strains belonging to 23 species of which 19 were Basidiomycetes seem to be intrinsically "resistant" to all drugs. Comparison of the antifungal susceptibility profiles of the 4240 clinical isolates and the 315 reference strains belonging to 53 shared species showed similar results. Even in the absence of demonstrated in vitro/in vivo correlation, knowing the in vitro susceptibility to systemic antifungal agents and the putative intrinsic resistance of yeast species present in the environment is important because they could become opportunistic pathogens.
Pohler, Petra; Müller, Meike; Winkler, Carla; Schaudien, Dirk; Sewald, Katherina; Müller, Thomas H; Seltsam, Axel
Residual white blood cells (WBCs) in cellular blood components induce a variety of adverse immune events, including nonhemolytic febrile transfusion reactions, alloimmunization to HLA antigens, and transfusion-associated graft-versus-host disease (TA-GVHD). Pathogen reduction (PR) methods such as the ultraviolet C (UVC) light-based THERAFLEX UV-Platelets system were developed to reduce the risk of transfusion-transmitted infection. As UVC light targets nucleic acids, it interferes with the replication of both pathogens and WBCs. This preclinical study aimed to evaluate the ability of UVC light to inactivate contaminating WBCs in platelet concentrates (PCs). The in vitro and in vivo function of WBCs from UVC-treated PCs was compared to that of WBCs from gamma-irradiated and untreated PCs by measuring cell viability, proliferation, cytokine secretion, antigen presentation in vitro, and xenogeneic GVHD responses in a humanized mouse model. UVC light was at least as effective as gamma irradiation in preventing GVHD in the mouse model. It was more effective in suppressing T-cell proliferation (>5-log reduction in the limiting dilution assay), cytokine secretion, and antigen presentation than gamma irradiation. The THERAFLEX UV-Platelets (MacoPharma) PR system can substitute gamma irradiation for TA-GVHD prophylaxis in platelet (PLT) transfusion. Moreover, UVC treatment achieves suppression of antigen presentation and inhibition of cytokine accumulation during storage of PCs, which has potential benefits for transfusion recipients. © 2014 AABB.
María Guadalupe López Rivera
Full Text Available Introduction. Cervical cancer is the most common cancer among Mexican women. The goal of the present study was to determine the prevalence and distribution of HPV types in women from Mexico City. Methods. Our study was conducted in the Clinica de Especialidades de la Mujer de la Secretaría de la Defensa Nacional, Mexico. Random samples were taken from 929 healthy women requesting a cervical Papanicolaou examination. Detection and genotyping of HPV were performed by multiplex PCR, with the HPV4A ACE Screening kit (Seegene. Results. 85 of nine hundred twenty-nine women (9.1% were infected with HPV. Of HPV-positive women, 99% and 1% had high- and low-risk HPV genotypes, respectively. The prevalence of the 16 high-risk (HR HPV types that were screened was 43% : 42% (18 were HPV positive and 14% (16 were HPV positive, which includes coinfection. Multiple infections with different viral genotypes were detected in 10% of the positive cases. Abnormal cervical cytological results were found in only 15.3% of HPV-positive women, while 84.7% had normal cytological results. Conclusions. We found a similar prevalence of HPV to previous studies in Mexico. The heterogeneity of the HPV genotype distribution in Mexico is evident in this study, which found a high frequency of HPV HR genotypes, the majority of which were HPV 18.
Dyląg, Mariusz; Lis, Paweł; Niedźwiecka, Katarzyna; Ko, Young H; Pedersen, Peter L; Goffeau, Andre; Ułaszewski, Stanisław
We have investigated the antifungal activity of the pyruvic acid analogue: 3-bromopyruvate (3-BP). Growth inhibition by 3-BP of 110 strains of yeast-like and filamentous fungi was tested by standard spot tests or microdilution method. The human pathogen Cryptococcus neoformans exhibited a low Minimal Inhibitory Concentration (MIC) of 0.12-0.15 mM 3-BP. The high toxicity of 3-BP toward C. neoformans correlated with high intracellular accumulation of 3-BP and also with low levels of intracellular ATP and glutathione. Weak cytotoxicity towards mammalian cells and lack of resistance conferred by the PDR (Pleiotropic Drug Resistance) network in the yeast Saccharomyces cerevisiae, are other properties of 3-BP that makes it a novel promising anticryptococcal drug. Copyright © 2013 Elsevier Inc. All rights reserved.
Luo, Shanshan; Skerka, Christine; Kurzai, Oliver; Zipfel, Peter F
Candida albicans is a medically important fungus that can cause a wide range of diseases ranging from superficial infections to disseminated disease, which manifests primarily in immuno-compromised individuals. Despite the currently applied anti-fungal therapies, both mortality and morbidity caused by this human pathogenic fungus are still unacceptably high. Therefore new prophylactic and therapeutic strategies are urgently needed to prevent fungal infection. In order to define new targets for combating fungal disease, there is a need to understand the immune evasion strategies of C. albicans in detail. In this review, we summarize different sophisticated immune evasion strategies that are utilized by C. albicans. The description of the molecular mechanisms used for immune evasion does on one hand help to understand the infection process, and on the other hand provides valuable information to define new strategies and diagnostic approaches to fight and interfere with Candida infections. Copyright © 2013 Elsevier Ltd. All rights reserved.
Full Text Available Objective: To evaluate the antifungal activity of seaweed extracts against human fungal pathogens. Methods: Antifungal activity of six species of marine macro algae Codium decorticatum, Caulerpa scalpelliformis, Gracilaria crassa, Acanthophora spicifera, Sargassum wightii and Turbinaria conoides using different solvents acetone, methanol, chloroform, diethyl ether, ethyl acetate, hexane and aqueous were evaluated against Fusarium oxysporum, Fusarium udum, Fusarium solani, Rhizoctonia solani, Alternaria alternat, Botrytis cinerea, Candida albicans, Candida krusei, Aspergillus niger and Aspergillus flavus. Results: From the investigation, the maximum activity was recorded from Phaeophyceae, Chlorophyceae and Rhodophyceae respectively. The maximum inhibition zone was noted in acetone extract of T. conoides against F. udum. Conclusions: From these findings, it is concluded that brown seaweed Turbinaria conoides is more effective than the green and red seaweeds.
Douglas, Lois M; Konopka, James B
Candida albicans is a human fungal pathogen capable of causing lethal systemic infections. The plasma membrane plays key roles in virulence because it not only functions as a protective barrier, it also mediates dynamic functions including secretion of virulence factors, cell wall synthesis, invasive hyphal morphogenesis, endocytosis, and nutrient uptake. Consistent with this functional complexity, the plasma membrane is composed of a wide array of lipids and proteins. These components are organized into distinct domains that will be the topic of this review. Some of the plasma membrane domains that will be described are known to act as scaffolds or barriers to diffusion, such as MCC/eisosomes, septins, and sites of contact with the endoplasmic reticulum. Other zones mediate dynamic processes, including secretion, endocytosis, and a special region at hyphal tips that facilitates rapid growth. The highly organized architecture of the plasma membrane facilitates the coordination of diverse functions and promotes the pathogenesis of C. albicans.
Douglas, Lois M.; Konopka, James. B.
Candida albicans is a human fungal pathogen capable of causing lethal systemic infections. The plasma membrane plays key roles in virulence because it not only functions as a protective barrier, it also mediates dynamic functions including secretion of virulence factors, cell wall synthesis, invasive hyphal morphogenesis, endocytosis, and nutrient uptake. Consistent with this functional complexity, the plasma membrane is composed of a wide array of lipids and proteins. These components are organized into distinct domains that will be the topic of this review. Some of the plasma membrane domains that will be described are known to act as scaffolds or barriers to diffusion, such as MCC/eisosomes, septins, and sites of contact with the endoplasmic reticulum. Other zones mediate dynamic processes, including secretion, endocytosis, and a special region at hyphal tips that facilitates rapid growth. The highly organized architecture of the plasma membrane facilitates the coordination of diverse functions and promotes the pathogenesis of C. albicans. PMID:26920878
Full Text Available Bacterial resistance to antibiotics, first a major concern in the 1960s, has re-emerged worldwide over the last 20 years. The World Health Organization (WHO and other health organizations have, therefore, declared ‘war’ against human microbial pathogens, particularly hospital-acquired infections, and have made drug discovery a top priority for these diseases. Because these bacteria are refractory to conventional chemotherapy, medicinal and herbal plants used in various countries should be assessed for their therapeutic potential; these valuable bio-resources are a reservoir of complex bioactive molecules. Earlier studies from our laboratory on Rhazya stricta, a native herbal shrub of Asia, have shown that this plant has a number of therapeutic properties. In this study, we evaluated the antimicrobial activities of various concentrations of five solvent extracts (aqueous alkaloid, aqueous non-alkaloid, organic alkaloid, organic non-alkaloid and whole aqueous extracts derived from R. stricta leaves against several multidrug-resistant, human-pathogenic bacteria, including methicillin-resistant Staphylococcus aureus (MRSA and extended-spectrum beta-lactamase-positive Escherichia coli. In vitro, molecular and electron microscopy analyses conclusively demonstrated the antimicrobial effects of these extracts against a panel of Gram-negative and Gram-positive bacteria. The organic alkaloid extract was the most effective against E. coli and MRSA, resulting in cell membrane disruption visible with transmission electron microscopy. In the near future, we intend to further focus and delineate the molecular mechanism-of-action for specific alkaloids of R. stricta, particularly against MRSA.
Full Text Available Context. Usnea ghattensis G. Awasthi (Usneaceae endemic fruticose lichen found growing luxuriantly in Northern Western Ghats of India, it also contains Usnic acid as a major chemical and tested against some human pathogenic bacteria. Objective. To explore antimicrobial properties of Usnea ghattensis against some human pathogenic bacteria. Materials and Methods. The lichen was extracted in acetone, methanol, and ethanol. In vitro antimicrobial activity was tested initially by Kirby-Bauer technique of disc diffusion method and was confirmed by minimum inhibitory concentration using Broth microdilution method according to the NCCLS guidelines. Results. Ethanol extract was most effective against Bacillus cereus and Pseudomonas aeruginosa with a zone of inhibition 29.8 ± 0.6 mm and 12.3 ± 0.5 mm diameters at a concentration of 0.2 mg/mL. Acetone and methanol extract demonstrated almost similar activity against Staphylococcus aureus and the zone of inhibition was 24.6 ± 0.5 and 24.7 ± 0.4 mm. Only methanol extract was showing activity against Streptococcus faecalis with a 13.5 ± 0.8 mm zone. MIC value noted against Staphylococcus aureus and Streptococcus faecalis was 6.25 μg/mL and 25 μg/mL, whereas against Bacillus cereus and Pseudomonas aeruginosa, MIC calculated was 3.125 μg/mL and 200 μg/mL, respectively. Conclusion. The present study demonstrates the relatively higher activity of this lichen against not only gram (+ but significantly also against gram (− bacteria. This indicates that this lichen might be a rich source of effective antimicrobial agents.
Syed Babar Jamal
Full Text Available Corynebacterium diphtheriae (Cd is a Gram-positive human pathogen responsible for diphtheria infection and once regarded for high mortalities worldwide. The fatality gradually decreased with improved living standards and further alleviated when many immunization programs were introduced. However, numerous drug-resistant strains emerged recently that consequently decreased the efficacy of current therapeutics and vaccines, thereby obliging the scientific community to start investigating new therapeutic targets in pathogenic microorganisms. In this study, our contributions include the prediction of modelome of 13 C. diphtheriae strains, using the MHOLline workflow. A set of 463 conserved proteins were identified by combining the results of pangenomics based core-genome and core-modelome analyses. Further, using subtractive proteomics and modelomics approaches for target identification, a set of 23 proteins was selected as essential for the bacteria. Considering human as a host, eight of these proteins (glpX, nusB, rpsH, hisE, smpB, bioB, DIP1084, and DIP0983 were considered as essential and non-host homologs, and have been subjected to virtual screening using four different compound libraries (extracted from the ZINC database, plant-derived natural compounds and Di-terpenoid Iso-steviol derivatives. The proposed ligand molecules showed favorable interactions, lowered energy values and high complementarity with the predicted targets. Our proposed approach expedites the selection of C. diphtheriae putative proteins for broad-spectrum development of novel drugs and vaccines, owing to the fact that some of these targets have already been identified and validated in other organisms.
Mao, Yong; Singh-Varma, Anya; Hoffman, Tyler; Dhall, Sandeep; Danilkovitch, Alla; Kohn, Joachim
Biofilm, a community of bacteria, is tolerant to antimicrobial agents and ubiquitous in chronic wounds. In a chronic DFU (Diabetic Foot Ulcers) clinical trial, the use of a human cryopreserved viable amniotic membrane (CVAM) resulted in a high rate of wound closure and reduction of wound-related infections. Our previous study demonstrated that CVAM possesses intrinsic antimicrobial activity against a spectrum of wound-associated bacteria under planktonic culture conditions. In this study, we evaluated the effect of CVAM and cryopreserved viable umbilical tissue (CVUT) on biofilm formation of S. aureus and P. aeruginosa , the two most prominent pathogens associated with chronic wounds. Firstly, we showed that, like CVAM, CVUT released antibacterial activity against multiple bacterial pathogens and the devitalization of CVUT reduced its antibacterial activity. The biofilm formation was then measured using a high throughput method and an ex vivo porcine dermal tissue model. We demonstrate that the formation of biofilm was significantly reduced in the presence of CVAM- or CVUT-derived conditioned media compared to control assay medium. The formation of P. aeruginosa biofilm on CVAM-conditioned medium saturated porcine dermal tissues was reduced 97% compared with the biofilm formation on the control medium saturated dermal tissues. The formation of S. auerus biofilm on CVUT-conditioned medium saturated dermal tissues was reduced 72% compared with the biofilm formation on the control tissues. This study is the first to show that human cryopreserved viable placental tissues release factors that inhibit biofilm formation. Our results provide an explanation for the in vivo observation of their ability to support wound healing.
Full Text Available Biofilm, a community of bacteria, is tolerant to antimicrobial agents and ubiquitous in chronic wounds. In a chronic DFU (Diabetic Foot Ulcers clinical trial, the use of a human cryopreserved viable amniotic membrane (CVAM resulted in a high rate of wound closure and reduction of wound-related infections. Our previous study demonstrated that CVAM possesses intrinsic antimicrobial activity against a spectrum of wound-associated bacteria under planktonic culture conditions. In this study, we evaluated the effect of CVAM and cryopreserved viable umbilical tissue (CVUT on biofilm formation of S. aureus and P. aeruginosa, the two most prominent pathogens associated with chronic wounds. Firstly, we showed that, like CVAM, CVUT released antibacterial activity against multiple bacterial pathogens and the devitalization of CVUT reduced its antibacterial activity. The biofilm formation was then measured using a high throughput method and an ex vivo porcine dermal tissue model. We demonstrate that the formation of biofilm was significantly reduced in the presence of CVAM- or CVUT-derived conditioned media compared to control assay medium. The formation of P. aeruginosa biofilm on CVAM-conditioned medium saturated porcine dermal tissues was reduced 97% compared with the biofilm formation on the control medium saturated dermal tissues. The formation of S. auerus biofilm on CVUT-conditioned medium saturated dermal tissues was reduced 72% compared with the biofilm formation on the control tissues. This study is the first to show that human cryopreserved viable placental tissues release factors that inhibit biofilm formation. Our results provide an explanation for the in vivo observation of their ability to support wound healing.
Joseph R Fauver
Full Text Available Novel surveillance strategies are needed to detect the rapid and continuous emergence of infectious disease agents. Ideally, new sampling strategies should be simple to implement, technologically uncomplicated, and applicable to areas where emergence events are known to occur. To this end, xenosurveillance is a technique that makes use of blood collected by hematophagous arthropods to monitor and identify vertebrate pathogens. Mosquitoes are largely ubiquitous animals that often exist in sizable populations. As well, many domestic or peridomestic species of mosquitoes will preferentially take blood-meals from humans, making them a unique and largely untapped reservoir to collect human blood.We sought to take advantage of this phenomenon by systematically collecting blood-fed mosquitoes during a field trail in Northern Liberia to determine whether pathogen sequences from blood engorged mosquitoes accurately mirror those obtained directly from humans. Specifically, blood was collected from humans via finger-stick and by aspirating bloodfed mosquitoes from the inside of houses. Shotgun metagenomic sequencing of RNA and DNA derived from these specimens was performed to detect pathogen sequences. Samples obtained from xenosurveillance and from finger-stick blood collection produced a similar number and quality of reads aligning to two human viruses, GB virus C and hepatitis B virus.This study represents the first systematic comparison between xenosurveillance and more traditional sampling methodologies, while also demonstrating the viability of xenosurveillance as a tool to sample human blood for circulating pathogens.
Research into the aetiological agent of the most widespread form of severe malaria, Plasmodium falciparum, has benefitted enormously from the ability to culture and genetically manipulate blood-stage forms of the parasite in vitro. However, most malaria outside Africa is caused by a distinct Plasmodium species, Plasmodium vivax, and it has become increasingly apparent that zoonotic infection by the closely related simian parasite Plasmodium knowlesi is a frequent cause of life-threatening malaria in regions of southeast Asia. Neither of these important malarial species can be cultured in human cells in vitro, requiring access to primates with the associated ethical and practical constraints. We report the successful adaptation of P. knowlesi to continuous culture in human erythrocytes. Human-adapted P. knowlesi clones maintain their capacity to replicate in monkey erythrocytes and can be genetically modified with unprecedented efficiency, providing an important and unique model for studying conserved aspects of malarial biology as well as species-specific features of an emerging pathogen.
Moon, Robert; Hall, Joanna M.; Rangkuti, Farania; Ho, YungShwen; Almond, Neil M.; Mitchell, Graham Howard; Pain, Arnab; Holder, Anthony A.; Blackman, Michael J.
Research into the aetiological agent of the most widespread form of severe malaria, Plasmodium falciparum, has benefitted enormously from the ability to culture and genetically manipulate blood-stage forms of the parasite in vitro. However, most malaria outside Africa is caused by a distinct Plasmodium species, Plasmodium vivax, and it has become increasingly apparent that zoonotic infection by the closely related simian parasite Plasmodium knowlesi is a frequent cause of life-threatening malaria in regions of southeast Asia. Neither of these important malarial species can be cultured in human cells in vitro, requiring access to primates with the associated ethical and practical constraints. We report the successful adaptation of P. knowlesi to continuous culture in human erythrocytes. Human-adapted P. knowlesi clones maintain their capacity to replicate in monkey erythrocytes and can be genetically modified with unprecedented efficiency, providing an important and unique model for studying conserved aspects of malarial biology as well as species-specific features of an emerging pathogen.
Chacín-Bonilla, Leonor; Sánchez-Chávez, Yulaicy; Estévez, Jesús; Larreal, Yraima; Molero, Emelyn
A survey of 335 individuals, 1-65 years of age (mean ±SD of 20.8 ±15.7), in 6 communities from the San Carlos Island, Western Venezuela, was conducted to study the prevalence of serum antibody to Toxoplasma gondii. The indirect hemagglutination test showed an overall infection rate of 49.8% (167 of 335) that ranged 23-64.8% according to the locality. No association between antibody status and age or risk factors was detected. Higher antibody rates were found in a windward coast community, and...
Calvopiña, Manuel; Cevallos, William; Kumazawa, Hideo; Eisenberg, Joseph
Amphimerus spp. flukes are known to infect mammals, but human infections have not been confirmed. Microscopy of fecal samples from 397 persons from Ecuador revealed Opisthorchiidae eggs in 71 (24%) persons. Light microscopy of adult worms and scanning electron microscopy of eggs were compatible with descriptions of Amphimerus spp. This pathogen was only observed in communities that consumed undercooked fish.
Full Text Available Objective: To determine the prevalence of Mycoplasma genitalium (M. genitalium infection in HIV positive patients by PCR examination in Teratai Clinic of Dr. Hasan Sadikin General Hospital, Bandung in order to reduce sexually transmitted diseases, especially M. genitalium infection in HIV positive patients. Methods: This study was a cross-sectional study with consecutive sampling methods. Eighty one HIV positive patients attending the Teratai Clinic of Dr. Hasan Sadikin General Hospital, Bandung were recruited to be the subjects of this study. All subjects underwent history taking, physical examination, and PCR examination for M. genitalium. Specimens were taken from cervical smear in females and first void urine in male. Results: The prevalence of M. genitalium based on the PCR examination in HIV positive patients attended to Teratai Clinic Dr. Hasan Sadikin General Hospital Bandung was 9%. Conclusions: Mycoplasmal infection identification based on PCR examination should be considered for routine screening test to reduce the incidence of sexually transmitted diseases in HIV positive patients.
Alison E Mather
Full Text Available Throughout the 1990 s, there was an epidemic of multidrug resistant Salmonella Typhimurium DT104 in both animals and humans in Scotland. The use of antimicrobials in agriculture is often cited as a major source of antimicrobial resistance in pathogenic bacteria of humans, suggesting that DT104 in animals and humans should demonstrate similar prevalences of resistance determinants. Until very recently, only the application of molecular methods would allow such a comparison and our understanding has been hindered by the fact that surveillance data are primarily phenotypic in nature. Here, using large scale surveillance datasets and a novel Bayesian approach, we infer and compare the prevalence of Salmonella Genomic Island 1 (SGI1, SGI1 variants, and resistance determinants independent of SGI1 in animal and human DT104 isolates from such phenotypic data. We demonstrate differences in the prevalences of SGI1, SGI1-B, SGI1-C, absence of SGI1, and tetracycline resistance determinants independent of SGI1 between these human and animal populations, a finding that challenges established tenets that DT104 in domestic animals and humans are from the same well-mixed microbial population.
Osman, Kamelia M; Zolnikov, Tara Rava; Samir, Ahmed; Orabi, Ahmed
Goat and sheep milk is consumed by human populations throughout the world; as a result, it has been proposed as an alternative, nutrient-rich milk to feed infants allergic to cow’s milk. Unfortunately, potentially harmful bacteria have not been thoroughly tested in goat or sheep milk. Listeria monocytogenes is a harmful bacterium that causes adverse health effects if ingested by humans. The purpose of this study was to estimate the prevalence and characterize the phenotype, genotype, virulenc...
Inpankaew, Tawin; Schär, Fabian; Dalsgaard, Anders
Ancylostoma ceylanicum, a hookworm of canids and felids in Asia, is becoming the second most common hookworm infecting humans. In 2012, we investigated the prevalence and infection dynamics of and risk factors for hookworm infections in humans and dogs in a rural Cambodian village. Over 57% of th......; thus, we advocate for a One Health approach to control this zoonosis....
Iudicone, Paola; Fioravanti, Daniela; Bonanno, Giuseppina; Miceli, Michelina; Lavorino, Claudio; Totta, Pierangela; Frati, Luigi; Nuti, Marianna; Pierelli, Luca
Supplements to support clinical-grade cultures of mesenchymal stem cells (MSC) are required to promote growth and expansion of these cells. Platelet lysate (PL) is a human blood component which may replace animal serum in MSC cultures being rich in various growth factors. Here, we describe a plasma poor pathogen-free platelet lysate obtained by pooling 12 platelet (PLT) units, to produce a standardized and safe supplement for clinical-grade expansion of MSC. PL lots were obtained by combining 2 6-unit PLT pools in additive solution (AS) following a transfusional-based procedure including pathogen inactivation (PI) by Intercept technology and 3 cycles of freezing/thawing, followed by membrane removal. Three PI-PL and 3 control PL lots were produced to compare their ability to sustain bone marrow derived MSC selection and expansion. Moreover, two further PL, subjected to PI or not, were also produced starting from the same initial PLT pools to evaluate the impact of PI on growth factor concentration and capacity to sustain cell growth. Additional PI-PL lots were used for comparison with fetal bovine serum (FBS) on MSC expansion. Immunoregulatory properties of PI-PL-generated MSC were documented in vitro by mixed lymphocyte culture (MLC) and peripheral blood mononuclear cells (PBMC) mitogen induced proliferation. PI-PL and PL control lots had similar concentrations of 4 well-described growth factors endowed with MSC stimulating ability. Initial growth and MSC expansion by PI-PL and PL controls were comparable either using different MSC populations or in head to head experiments. Moreover, PI-PL and PL control sustained similar MSC growth of frozen/thawed MSC. Multilineage differentiation of PI-derived and PI-PL-derived MSC were maintained in any MSC cultures as well as their immunoregulatory properties. Finally, no direct impact of PI on growth factor concentration and MSC growth support was observed, whereas the capacity of FBS to sustain MSC expansion in basic
Doheny, Dana; Srinivasan, Ram; Pagant, Silvere; Chen, Brenden; Yasuda, Makiko; Desnick, Robert J
Fabry Disease (FD), an X linked lysosomal storage disease due to pathogenic α-galactosidase A ( GLA ) mutations, results in two major subtypes, the early-onset Type 1 'Classic' and the Type 2 'Later-Onset' phenotypes. To identify previously unrecognised patients, investigators screened cardiac, renal and stroke clinics by enzyme assays. However, some screening studies did not perform confirmatory GLA mutation analyses, and many included recently recognised 'benign/likely-benign' variants, thereby inflating prevalence estimates. Online databases were searched for all FD screening studies in high-risk clinics (1995-2017). Studies reporting GLA mutations were re-analysed for pathogenic mutations, sex and phenotype. Phenotype-specific and sex-specific prevalence rates were determined. Of 67 studies, 63 that screened 51363patients (33943M and 17420F) and provided GLA mutations were reanalysed for disease-causing mutations. Of reported GLA mutations, benign variants occurred in 47.9% of males and 74.1% of females. The following were the revised prevalence estimates: among 36820 (23954M and 12866F) haemodialysis screenees, 0.21% males and 0.15% females; among 3074 (2031M and 1043F) renal transplant screenees, 0.25% males and no females; among 5491 (4054M and 1437F) cardiac screenees, 0.94% males and 0.90% females; and among 5978 (3904M and 2074F) stroke screenees, 0.13% males and 0.14% females. Among male and female screenees with pathogenic mutations, the type 1 Classic phenotype was predominant (~60%), except more male cardiac patients (75%) had type 2 Later-Onset phenotype. Compared with previous findings, reanalysis of 63 studies increased the screenee numbers (~3.4-fold), eliminated 20 benign/likely benign variants, and provided more accurate sex-specific and phenotype-specific prevalence estimates, ranging from ~0.13% of stroke to ~0.9% of cardiac male or female screenees. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article
Olesen, Tina Bech; Munk, Christian; Christensen, Jane
among men in sub-Saharan Africa, which could contribute to the high rates of penile and cervical cancer in this part of the world. Implementation of the prophylactic HPV vaccines could potentially help prevent this large burden of HPV and HPV-associated disease in sub-Saharan Africa. CLINICALTRIALS...... was 78.2% (95% CI 54.2 to 91.6) among HIV-positive and 49.4% (95% CI 30.4 to 68.6) among HIV-negative men (p=0.0632). When restricting the analyses to PCR-based studies, the pooled prevalence of any HPV was 84.5% (95% CI 74.2 to 91.2) among HIV-positive and 56.4% (95% CI 49.7 to 62.9) among HIV...
Rusan, M; Klug, Tejs Ehlers; Henriksen, Jens-Jacob Mølby
tonsillar disease (n = 55). HPV was detected by nested PCR with PGMY 09/11 and GP5+/GP6+L1 consensus primers, and typed by sequencing. Samples were also analyzed using a higher-throughput method, the CLART HPV 2 Clinical Array Assay. The overall prevalence of HPV tonsillar infection was 1.25 % (1/80, 95...... % CI 0.03-6.77 %) by nested PCR, and 0 % by CLART HPV2 Clinical Array. The HPV-positive patient was a 16-year-old female with recurrent tonsillitis and tonsillar hypertrophy. The type detected was HPV6. HPV was not detected in the contralateral tonsil of this patient. Compared to cervical HPV...
Morales, Anabelle; Garland, Jay L.; Lim, Daniel V.
Plants may serve as reservoirs for human-associated bacteria (H-AB) in long-term space missions containing bioregenerative life support systems. The current study examined the abilities of five human-associated potential pathogens, Pseudomonas aeruginosa, Pseudomonas cepacia, Staphylococcus aureus, Streptococcus pyogenes, and Escherichia coli, to colonize and grow in the rhizosphere of hydroponically grown wheat, a candidate crop for life support. All of these bacteria have been recovered from past NASA missions and present potential problems for future missions. The abilities of these organisms to adhere to the roots of axenic five-day-old wheat (Triticum aestivum L. cv. Yecora rojo) were evaluated by enumeration of the attached organisms after a one hour incubation of roots in a suspension (approximately 10(exp 8 cu/ml)) of the H-AB. Results showed that a greater percentage of P. aeruginosa cells adhered to the wheat roots than the other four H-AB. Similarly incubated seedlings were also grown under attempted axenic conditions for seven days to examine the potential of each organism to proliferate in the rhizosphere (root colonization capacity). P. cepacia and P. aeruginosa showed considerable growth. E. coli and S. aureus showed no significant growth, and S. pyogenes died off in the wheat rhizosphere. Studies examining the effects of competition on the survival of these microorganisms indicated that P. aeruginosa was the only organism that survived in the rhizosphere of hydroponically grown wheat in the presence of different levels of microbial competition.
Lemaire, D.; Barbosa, T.; Rihet, P.
Vaccine development faces major difficulties partly because of genetic variation in both infectious organisms and humans. This causes antigenic variation in infectious agents and a high interindividual variability in the human response to the vaccine. The exponential growth of genome sequence information has induced a shift from conventional culture-based to genome-based vaccinology, and allows the tackling of challenges in vaccine development due to pathogen genetic variability. Additionally, recent advances in immunogenetics and genomics should help in the understanding of the influence of genetic factors on the interindividual and interpopulation variations in immune responses to vaccines, and could be useful for developing new vaccine strategies. Accumulating results provide evidence for the existence of a number of genes involved in protective immune responses that are induced either by natural infections or vaccines. Variation in immune responses could be viewed as the result of a perturbation of gene networks; this should help in understanding how a particular polymorphism or a combination thereof could affect protective immune responses. Here we will present: i) the first genome-based vaccines that served as proof of concept, and that provided new critical insights into vaccine development strategies; ii) an overview of genetic predisposition in infectious diseases and genetic control in responses to vaccines; iii) population genetic differences that are a rationale behind group-targeted vaccines; iv) an outlook for genetic control in infectious diseases, with special emphasis on the concept of molecular networks that will provide a structure to the huge amount of genomic data
Lesley Joan Collins
Full Text Available ncRNAs are key genes in many human diseases including cancer and viral infection, as well as providing critical functions in pathogenic organisms such as fungi, bacteria, viruses and protists. Until now the identification and characterization of ncRNAs associated with disease has been slow or inaccurate requiring many years of testing to understand complicated RNA and protein gene relationships. High-throughput sequencing now offers the opportunity to characterize miRNAs, siRNAs, snoRNAs and long ncRNAs on a genomic scale making it faster and easier to clarify how these ncRNAs contribute to the disease state. However, this technology is still relatively new, and ncRNA discovery is not an application of high priority for streamlined bioinformatics. Here we summarize background concepts and practical approaches for ncRNA analysis using high-throughput sequencing, and how it relates to understanding human disease. As a case study, we focus on the parasitic protists Giardia lamblia and Trichomonas vaginalis, where large evolutionary distance has meant difficulties in comparing ncRNAs with those from model eukaryotes. A combination of biological, computational and sequencing approaches has enabled easier classification of ncRNA classes such as snoRNAs, but has also aided the identification of novel classes. It is hoped that a higher level of understanding of ncRNA expression and interaction may aid in the development of less harsh treatment for protist-based diseases.
Collins, Lesley Joan
ncRNAs are key genes in many human diseases including cancer and viral infection, as well as providing critical functions in pathogenic organisms such as fungi, bacteria, viruses, and protists. Until now the identification and characterization of ncRNAs associated with disease has been slow or inaccurate requiring many years of testing to understand complicated RNA and protein gene relationships. High-throughput sequencing now offers the opportunity to characterize miRNAs, siRNAs, small nucleolar RNAs (snoRNAs), and long ncRNAs on a genomic scale, making it faster and easier to clarify how these ncRNAs contribute to the disease state. However, this technology is still relatively new, and ncRNA discovery is not an application of high priority for streamlined bioinformatics. Here we summarize background concepts and practical approaches for ncRNA analysis using high-throughput sequencing, and how it relates to understanding human disease. As a case study, we focus on the parasitic protists Giardia lamblia and Trichomonas vaginalis, where large evolutionary distance has meant difficulties in comparing ncRNAs with those from model eukaryotes. A combination of biological, computational, and sequencing approaches has enabled easier classification of ncRNA classes such as snoRNAs, but has also aided the identification of novel classes. It is hoped that a higher level of understanding of ncRNA expression and interaction may aid in the development of less harsh treatment for protist-based diseases. PMID:22303390
Khan, Usman Ali; Rahman, Hazir; Qasim, Muhammad; Hussain, Anwar; Azizllah, Azizullah; Murad, Waheed; Khan, Zakir; Anees, Muhammad; Adnan, Muhammad
Plants are rich source of chemical compounds that are used to accomplish biological activity. Indigenously crude extracts of plants are widely used as herbal medicine for the treatment of infections by people of different ethnic groups. The present investigation was carried out to evaluate the biological potential of Alkanna tinctoria leaves extract from district Charsadda, Pakistan against multidrug resistant human pathogenic bacteria including Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Anti-multi-drug resistant bacterial activity of aqueous, chloroform, ethanol and hexane extracts of Alkanna tinctoria leaves were evaluated by well diffusion method. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of different extracts were determined. Moreover qualitative phytochemicals screening of the studied extracts was performed. All four selected bacteria including A. baumannii, E. coli, P. aeruginosa and S. aureus were categorized as multi-drug resistant (MDR) as they were found to be resistant to 13, 10, 19 and 22 antibiotics belonging to different groups respectively. All the four extract showed potential activity against S. aureus as compare to positive control antibiotic (Imipenem). Similarly among the four extracts of Alkanna tinctoria leaves, aqueous extract showed best activity against A. baumannii (10±03 mm), P. aeruginosa (12±0.5 mm), and S. aureus (14±0.5 mm) as compare to Imipenem. The MICs and MBCs results also showed quantitative concentration of plant extracts to inhibit or kill MDR bacteria. When phytochemicals analysis was performed it was observed that aqueous and ethanol extracts showed phytochemicals with large number as well as volume, especially Alkaloides, Flavonoides and Charbohydrates. The undertaken study demonstrated that all the four extracts of Alkanna tinctoria leaves exhibited considerable antibacterial activity against MDR isolates. Finding from the
Du, Han; Puri, Sumant; McCall, Andrew; Norris, Hannah L; Russo, Thomas; Edgerton, Mira
ESKAPE ( Enterococcus faecium , Staphylococcus aureus , Klebsiella pneumoniae , Acinetobacter baumanni , Pseudomonas aeruginosa , and Enterobacter species) pathogens have characteristic multiple-drug resistance and cause an increasing number of nosocomial infections worldwide. Peptide-based therapeutics to treat ESKAPE infections might be an alternative to conventional antibiotics. Histatin 5 (Hst 5) is a salivary cationic histidine-rich peptide produced only in humans and higher primates. It has high antifungal activity against Candida albicans through an energy-dependent, non-lytic process; but its bactericidal effects are less known. We found Hst 5 has bactericidal activity against S. aureus (60-70% killing) and A. baumannii (85-90% killing) in 10 and 100 mM sodium phosphate buffer (NaPB), while killing of >99% of P. aeruginosa , 60-80% E. cloacae and 20-60% of E. faecium was found in 10 mM NaPB. Hst 5 killed 60% of biofilm cells of P. aeruginosa , but had reduced activity against biofilms of S. aureus and A. baumannii . Hst 5 killed 20% of K. pneumonia biofilm cells but not planktonic cells. Binding and uptake studies using FITC-labeled Hst 5 showed E. faecium and E. cloacae killing required Hst 5 internalization and was energy dependent, while bactericidal activity was rapid against P. aeruginosa and A. baumannii suggesting membrane disruption. Hst 5-mediated killing of S. aureus was both non-lytic and energy independent. Additionally, we found that spermidine conjugated Hst 5 (Hst5-Spd) had improved killing activity against E. faecium, E. cloacae , and A. baumannii . Hst 5 or its derivative has antibacterial activity against five out of six ESKAPE pathogens and may be an alternative treatment for these infections.
José F Muñoz
Full Text Available Three closely related thermally dimorphic pathogens are causal agents of major fungal diseases affecting humans in the Americas: blastomycosis, histoplasmosis and paracoccidioidomycosis. Here we report the genome sequence and analysis of four strains of the etiological agent of blastomycosis, Blastomyces, and two species of the related genus Emmonsia, typically pathogens of small mammals. Compared to related species, Blastomyces genomes are highly expanded, with long, often sharply demarcated tracts of low GC-content sequence. These GC-poor isochore-like regions are enriched for gypsy elements, are variable in total size between isolates, and are least expanded in the avirulent B. dermatitidis strain ER-3 as compared with the virulent B. gilchristii strain SLH14081. The lack of similar regions in related species suggests these isochore-like regions originated recently in the ancestor of the Blastomyces lineage. While gene content is highly conserved between Blastomyces and related fungi, we identified changes in copy number of genes potentially involved in host interaction, including proteases and characterized antigens. In addition, we studied gene expression changes of B. dermatitidis during the interaction of the infectious yeast form with macrophages and in a mouse model. Both experiments highlight a strong antioxidant defense response in Blastomyces, and upregulation of dioxygenases in vivo suggests that dioxide produced by antioxidants may be further utilized for amino acid metabolism. We identify a number of functional categories upregulated exclusively in vivo, such as secreted proteins, zinc acquisition proteins, and cysteine and tryptophan metabolism, which may include critical virulence factors missed before in in vitro studies. Across the dimorphic fungi, loss of certain zinc acquisition genes and differences in amino acid metabolism suggest unique adaptations of Blastomyces to its host environment. These results reveal the dynamics
Muñoz, José F; Gauthier, Gregory M; Desjardins, Christopher A; Gallo, Juan E; Holder, Jason; Sullivan, Thomas D; Marty, Amber J; Carmen, John C; Chen, Zehua; Ding, Li; Gujja, Sharvari; Magrini, Vincent; Misas, Elizabeth; Mitreva, Makedonka; Priest, Margaret; Saif, Sakina; Whiston, Emily A; Young, Sarah; Zeng, Qiandong; Goldman, William E; Mardis, Elaine R; Taylor, John W; McEwen, Juan G; Clay, Oliver K; Klein, Bruce S; Cuomo, Christina A
Three closely related thermally dimorphic pathogens are causal agents of major fungal diseases affecting humans in the Americas: blastomycosis, histoplasmosis and paracoccidioidomycosis. Here we report the genome sequence and analysis of four strains of the etiological agent of blastomycosis, Blastomyces, and two species of the related genus Emmonsia, typically pathogens of small mammals. Compared to related species, Blastomyces genomes are highly expanded, with long, often sharply demarcated tracts of low GC-content sequence. These GC-poor isochore-like regions are enriched for gypsy elements, are variable in total size between isolates, and are least expanded in the avirulent B. dermatitidis strain ER-3 as compared with the virulent B. gilchristii strain SLH14081. The lack of similar regions in related species suggests these isochore-like regions originated recently in the ancestor of the Blastomyces lineage. While gene content is highly conserved between Blastomyces and related fungi, we identified changes in copy number of genes potentially involved in host interaction, including proteases and characterized antigens. In addition, we studied gene expression changes of B. dermatitidis during the interaction of the infectious yeast form with macrophages and in a mouse model. Both experiments highlight a strong antioxidant defense response in Blastomyces, and upregulation of dioxygenases in vivo suggests that dioxide produced by antioxidants may be further utilized for amino acid metabolism. We identify a number of functional categories upregulated exclusively in vivo, such as secreted proteins, zinc acquisition proteins, and cysteine and tryptophan metabolism, which may include critical virulence factors missed before in in vitro studies. Across the dimorphic fungi, loss of certain zinc acquisition genes and differences in amino acid metabolism suggest unique adaptations of Blastomyces to its host environment. These results reveal the dynamics of genome evolution
Heidi C Vebø
Full Text Available Urinary tract infection (UTI is the most common infection caused by enterococci, and Enterococcus faecalis accounts for the majority of enterococcal infections. Although a number of virulence related traits have been established, no comprehensive genomic or transcriptomic studies have been conducted to investigate how to distinguish pathogenic from non-pathogenic E. faecalis in their ability to cause UTI. In order to identify potential genetic traits or gene regulatory features that distinguish pathogenic from non-pathogenic E. faecalis with respect to UTI, we have performed comparative genomic analysis, and investigated growth capacity and transcriptome profiling in human urine in vitro. Six strains of different origins were cultivated and all grew readily in human urine. The three strains chosen for transcriptional analysis showed an overall similar response with respect to energy and nitrogen metabolism, stress mechanism, cell envelope modifications, and trace metal acquisition. Our results suggest that citrate and aspartate are significant for growth of E. faecalis in human urine, and manganese appear to be a limiting factor. The majority of virulence factors were either not differentially regulated or down-regulated. Notably, a significant up-regulation of genes involved in biofilm formation was observed. Strains from different origins have similar capacity to grow in human urine. The overall similar transcriptional responses between the two pathogenic and the probiotic strain suggest that the pathogenic potential of a certain E. faecalis strain may to a great extent be determined by presence of fitness and virulence factors, rather than the level of expression of such traits.
Wille, I; Mayr, A; Kreidl, P; Brühwasser, C; Hinterberger, G; Fritz, A; Posch, W; Fuchs, S; Obwegeser, A; Orth-Höller, D; Lass-Flörl, C
In intensive care units (ICUs), inanimate surfaces and equipment may be contaminated by nosocomial pathogens, including multi-drug-resistant micro-organisms. To assess the degree of environmental contamination close to and distant from patients, and contamination of healthcare workers' (HCWs) hands with nosocomial pathogens under real-life conditions and to investigate potential transmission events. Over the course of three weeks, agar contact samples were taken close to and distant from patient areas and from HCWs' hands in eight ICUs of a tertiary care hospital in Innsbruck, Austria. Each ICU was visited once without announcement. Species identification and antimicrobial susceptibility testing were performed according to standard methods, and corresponding strains from patient, environment and hand samples were genotyped using pulsed-field gel electrophoresis. Among 523 samples, HCWs' hands were most frequently contaminated with potentially pathogenic bacteria (15.2%), followed by areas close to patients (10.9%) and areas distant from patients (9.1%). Gram-positive bacteria were identified most often (67.8%), with Enterococcus spp. being the most prevalent species (70% vancomycin sensitive and 30% vancomycin resistant) followed by Staphylococcus aureus, of which 64% were classified as meticillin-resistant Staphylococcus aureus. Molecular typing documented identical strains among patient, environment and hand isolates. This study found widespread contamination of the ICU environment with clinically relevant pathogens, including multi-drug-resistant micro-organisms, despite cleaning and disinfection. The bioburden might not be restricted to areas close to patients. The role of extended environmental disinfection of areas distant from patients in order to improve infection prevention needs further discussion. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
Oct 25, 2015 ... Abstract: Background: Hepatitis. C virus (HCV) is a major public health problem for Human Immu- nodeficiency virus (HIV) infected population. Both infections share same routes of transmission, and quite often co-exist, with dual infections associated with recipro- cal and mutually more rapid pro- gression ...
Feb 16, 2016 ... development of placental malaria in HIV‑positive women (odds ratio: 21.60; 95% ..... Marital status. Single. 6 (5.9). 4 (3.9). Married. 96 (94.1). 98 (96.1) ... χ2=16.65; df=2; P=<0.001. df=Degrees of freedom; HIV=Human.
Background: Hepatitis C virus (HCV) is a major public health problem for Human Immunodeficiency virus (HIV) infected population. Both infections share same routes of transmission, and quite often co-exist, with dual infections associated with reciprocal and mutually more rapid progression than either infection alone.
Objective: Human immunodeficiency virus (HIV), hepatitis B virus, and hepatitis C viruses (HCV) are major causes of mortality and morbidity worldwide. They are also among the commonest transfusiontransmissible infectious agents. Students of higher institutions are often used as voluntary unpaid donors by many ...
Human Pappiloma Virus (HPV) infection is a disease of global public health importance, culminating into a high risk of cervical cancer. Most of the risk factors are modifiable, thus making HPV itself preventable. Efforts towards community HPV prevention and vaccination have not yielded the desired results, most especially ...
Background: Anaemia is the most commonly encountered haematological abnormality in human immunodeficiency virus (HIV) positive patients with estimates climbing as high as 95% depending on clinical settings. The twin effects of HIV infection and anaemia in pregnancy is associated with adverse maternal and ...
Records 700 - 1600 ... suggesting chances of increased spread to humans, and the disease being misdiagnosed for malaria. .... Despite farmers knowledge of the .... In the current study, camels showed negative results, possibly due to few samples collected as most farmers were unwilling to let their animals be sampled.
Brucellosis is an emerging zoonotic disease that poses a threat to both livestock and public health in east Africa. There are several reports of occurrence of the disease in livestock populations especially in Tanzania and Kenya, suggesting chances of increased spread to humans, and the disease being misdiagnosed for ...
Patwardhan, Vrushali; Kumar, Dinesh; Goel, Varun; Singh, Sarman
The aim and objective of this study was to assess the temporal changes in the microbiological profiles and antimicrobial resistance patterns of uropathogens in pediatric community-acquired UTI. This is a retrospective analysis of data collected over a Scattered period of 5 years. The baseline data collected were from January to December 2009, and the second period considered for comparison was from January to December 2014. Urine specimens from children (Antibiotic sensitivity was put up by Kirby-Bauer disc diffusion method as per the Clinical and Laboratory Standard Institute guidelines. In the year 2009, 340 of 2104 (16.15%) urine specimens yielded significant colony count, whereas in 2014, it was 407 of 2212 (18.39%) ( P = 0.051). Escherichia coli was the predominant pathogen and was significantly more prevalent in girls than in boys ( P resistance to ampicillin (from 40.29% to 58.72%), amoxyclav (from 26.17% to 40.54%), nitrofurantoin (from 28.82% to 39.06%), and norfloxacin (from 30% to 41.42%). However, the maximum increase in the resistance was noted for co-trimoxazole from 35.58% in 2009 to 63.39% in 2014 ( P = 0.0000058). The prevalence of extended-spectrum beta-lactamases (ESBLs) has also significantly increased from 21.7% to 33.16% ( P = 0.0045). Although E. coli remains the prime pathogen in pediatric UTI, the prevalence of resistance has dramatically increased over the 5-year study period. Our study highlights the emergence of community-acquired ESBL-producing uropathogens in children proclaiming treatment challenges.
Sente, Celsus; Erume, Joseph; Naigaga, Irene; Mulindwa, Julius; Ochwo, Sylvester; Magambo, Phillip Kimuda; Namara, Benigna Gabriela; Kato, Charles Drago; Sebyatika, George; Muwonge, Kevin; Ocaido, Michael
Pathogenic water dwelling protozoa such as Acanthamoeba spp., Hartmannella spp., Naegleria spp., Cryptosporidium spp. and Giardia spp. are often responsible for devastating illnesses especially in children and immunocompromised individuals, yet their presence and prevalence in certain environment in sub-Saharan Africa is still unknown to most researchers, public health officials and medical practitioners. The objective of this study was to establish the presence and prevalence of pathogenic free-living amoeba (FLA), Cryptosporidium and Giardia in Queen Elizabeth Protected Area (QEPA). Samples were collected from communal taps and natural water sites in QEPA. Physical water parameters were measured in situ. The samples were processed to detect the presence of FLA trophozoites by xenic cultivation, Cryptosporidium oocysts by Ziehl-Neelsen stain and Giardia cysts by Zinc Sulphate floatation technique. Parasites were observed microscopically, identified, counted and recorded. For FLA, genomic DNA was extracted for amplification and sequencing. Both natural and tap water sources were contaminated with FLA, Cryptosporidium spp. and Giardia spp. All protozoan parasites were more abundant in the colder rainy season except for Harmannella spp. and Naegleria spp. which occurred more in the warmer months. The prevalence of all parasites was higher in tap water than in natural water samples. There was a strong negative correlation between the presence of Acanthamoeba spp., Hartmannella spp., Cryptosporidium spp. and Giardia spp. with Dissolved Oxygen (DO) (P protozoa that could possibly be the cause of a number of silent morbidities and mortalities among rural households in QEPA. This implies that water used by communities in QEPA is of poor quality and predisposes them to a variety of protozoan infections including the FLA whose public health importance was never reported, thus necessitating adoption of proper water safety measures.
Sedionoto, Blego; Anamnart, Witthaya
Hookworm infection and Stronyloidiasis are public health problem in the worldwide which both of them could infective in human by penetrated on skin and they have potential risk from Gastrointestinal zoonotic helminths of pets, including cats. We investigated the prevalence soil transmitted helminths infection in human and cats used modified Formal-Ether Concentration and agar plate culture. Fecal samples of 23 cats and human from Naitung and Subua Villages (area study 1), and fecal samples of 15 cats and 17 humans from Thasala Beach villages (area study 2) were collected. Result of study in area study 1 showed prevalence of infection in human was not hookworm and strongyloidiasis but 10% humans have infected Ascaris and Tricuris, and in cats have infected by hookworm 75.2% and S. strercoralis 8.5%, toxocara 13%, spirometra 13% and overall prevalence 82.5%. In area study 2 showed in human has infected by Trichuris 100% and S. stercoralis 29.4% and in cats have infected by hookworm 100% and S. strercoralis 40%, toxocora 20%, and spirometra 20%. Helminth infection found in both humans in two areas study are S. strercoralis. Hookworms were the most common helminth in cats but did not connection with infection in human, while S. strercoralis was helminth infection in cats which has potential zoonotic disease to human.
Franz, E.; Bruggen, van A.H.C.; Semenov, A.M.
An overview is given of recent problems with food-borne enteric human pathogens originating from contaminated agricultural animals. The need for risk analysis is indicated, and the generally accepted procedure for risk assessment is outlined. Two main approaches to probability and risk calculations,
Fenner, Lukas; Egger, Matthias; Bodmer, Thomas; Furrer, Hansjakob; Ballif, Marie; Battegay, Manuel; Helbling, Peter; Fehr, Jan; Gsponer, Thomas; Rieder, Hans L.; Zwahlen, Marcel; Hoffmann, Matthias; Bernasconi, Enos; Cavassini, Matthias; Calmy, Alexandra; Dolina, Marisa; Frei, Reno; Janssens, Jean-Paul; Borrell, Sonia; Stucki, David; Schrenzel, Jacques; Böttger, Erik C.; Gagneux, Sebastien
The phylogeographic population structure of Mycobacterium tuberculosis suggests local adaptation to sympatric human populations. We hypothesized that HIV infection, which induces immunodeficiency, will alter the sympatric relationship between M. tuberculosis and its human host. To test this hypothesis, we performed a nine-year nation-wide molecular-epidemiological study of HIV–infected and HIV–negative patients with tuberculosis (TB) between 2000 and 2008 in Switzerland. We analyzed 518 TB patients of whom 112 (21.6%) were HIV–infected and 233 (45.0%) were born in Europe. We found that among European-born TB patients, recent transmission was more likely to occur in sympatric compared to allopatric host–pathogen combinations (adjusted odds ratio [OR] 7.5, 95% confidence interval [95% CI] 1.21–infinity, p = 0.03). HIV infection was significantly associated with TB caused by an allopatric (as opposed to sympatric) M. tuberculosis lineage (OR 7.0, 95% CI 2.5–19.1, p<0.0001). This association remained when adjusting for frequent travelling, contact with foreigners, age, sex, and country of birth (adjusted OR 5.6, 95% CI 1.5–20.8, p = 0.01). Moreover, it became stronger with greater immunosuppression as defined by CD4 T-cell depletion and was not the result of increased social mixing in HIV–infected patients. Our observation was replicated in a second independent panel of 440 M. tuberculosis strains collected during a population-based study in the Canton of Bern between 1991 and 2011. In summary, these findings support a model for TB in which the stable relationship between the human host and its locally adapted M. tuberculosis is disrupted by HIV infection. PMID:23505379
Anderson Messias Rodrigues
Full Text Available Sporothrix infections are emerging as an important human and animal threat among otherwise healthy patients, especially in Brazil and China. Correct identification of sporotrichosis agents is beneficial for epidemiological surveillance, enabling implementation of adequate public-health policies and guiding antifungal therapy. In areas of limited resources where sporotrichosis is endemic, high-throughput detection methods that are specific and sensitive are preferred over phenotypic methods that usually result in misidentification of closely related Sporothrix species. We sought to establish rolling circle amplification (RCA as a low-cost screening tool for species-specific identification of human-pathogenic Sporothrix. We developed six species-specific padlock probes targeting polymorphisms in the gene encoding calmodulin. BLAST-searches revealed candidate probes that were conserved intraspecifically; no significant homology with sequences from humans, mice, plants or microorganisms outside members of Sporothrix were found. The accuracy of our RCA-based assay was demonstrated through the specificity of probe-template binding to 25 S. brasiliensis, 58 S. schenckii, 5 S. globosa, 1 S. luriei, 4 S. mexicana, and 3 S. pallida samples. No cross reactivity between closely related species was evident in vitro, and padlock probes yielded 100% specificity and sensitivity down to 3 x 10 6 copies of the target sequence. RCA-based speciation matched identifications via phylogenetic analysis of the gene encoding calmodulin and the rDNA operon (kappa 1.0; 95% confidence interval 1.0-1.0, supporting its use as a reliable alternative to DNA sequencing. This method is a powerful tool for rapid identification and specific detection of medically relevant Sporothrix, and due to its robustness has potential for ecological studies.
Full Text Available The most prevalent, curable sexually important diseases are those caused by Chlamydia trachomatis (C. trachomatis and genital mycoplasmas. An important characteristic of these infections is their ability to cause long-term sequels in upper genital tract, thus potentially affecting the reproductive health in both sexes. Pelvic inflammatory disease (PID, tubal factor infertility (TFI, and ectopic pregnancy (EP are well documented complications of C. trachomatis infection in women. The role of genital mycoplasmas in development of PID, TFI, and EP requires further evaluation, but growing evidence supports a significant role for these in the pathogenesis of chorioamnionitis, premature membrane rupture, and preterm labor in pregnant woman. Both C. trachomatis and genital mycoplasmas can affect the quality of sperm and possibly influence the fertility of men. For the purpose of this paper, basic, epidemiologic, clinical, therapeutic, and public health issue of these infections were reviewed and discussed, focusing on their impact on human reproductive health.
Hebnes, Julie Buchholt; Munk, Christian; Nøhr, Bugge; Nielsen, Ann; Jørgensen, Hans Ole; Iftner, Thomas; Kjaer, Susanne Krüger
It is crucial to understand the epidemiology and natural history of human papillomavirus (HPV) infection in both men and women, to prevent the increasing HPV-related disease burden in men. Data on HPV prevalence among men in the general population are limited. In this cross-sectional population-based study, we aimed to estimate genital HPV infection prevalence in Danish men using 2 different test methods. Penile swab samples from 2460 male employees and conscripts at military barracks in Denmark were tested for HPV DNA with the hybrid capture 2 (HC2) method, and a polymerase chain reaction (PCR) assay, Inno-LiPA. The overall and age- and type-specific prevalence of HPV infection with 95% confidence intervals (CIs) were estimated, and the correlation between the 2 assays was assessed. The overall HPV prevalence was 22.2% (95% CI, 20.6-23.9) in the HC2 test and 41.8% (95% CI, 39.9-43.8) with PCR. Of the PCR-positive samples, 50.9% were negative in the HC2 test. Of 183 PCR-positive samples that could not be genotyped (HPVX), 88.0% (95% CI, 83.2-92.7) were HC2 negative. The most prevalent types were HPV-51, HPV-16, HPV-66, HPV-53, and HPV-6. The prevalence of high-risk and low-risk HPV peaked among men aged 20 to 29 years, whereas the HPVX prevalence increased with age. Human papillomavirus is highly prevalent in the general male population of Denmark, with HPV-16 and HPV-51 being the most prevalent. Polymerase chain reaction detects twice as many positive samples as HC2 but includes HPVX, possibly representing cutaneous HPV types found on normal genital skin.
Zhang, Shun-Xiang; Cheng, Jin-Quan; Ma, Han-Wu; He, Jian-Fan; Cheng, Xiao-Wen; Jiang, Li-Juan; Mou, Jin; Wu, Chun-Li; Lv, Xing; Zhang, Shao-Hua; Zhang, Ya-De; Wu, Yong-Sheng; Wang, Xin
Based on analyzing the characteristics of a case with human avian influenza and the effects of field epidemiological study. An emergency-response-system was started up to follow the probable human Highly Pathogenic Avian Influenza case initially detected by the "Undefined Pneumonia Surveillance System of Shenzhen". Public health professionals administered several epidemiologic investigations and giving all the contacts of the patient with a 7-day-long medical observation for temporally related influenza-like illness. Reverse transcriptase-polymerase chain reaction (RT-PCR) with primers for H5 and N1 was applied to test respiratory tract samples and/or throat swabs of the patient and all his contacts specific for the hemagglutinin gene of influenza A H5N1. Activities and strategies such as media response,notification in the public, communications with multiple related sectors, social participation and information exchange with Hong Kong were involved in field control and management. The patient was a male, 31 years old,with an occupation as a truck driver in a factory,and had been residing in Shenzhen for 7 years. Started with an influenza-like syndrome, the patient received treatment on the 4th day of the onset, from a clinic and on the 6th day from a regular hospital. On the 8th day of the disease course, he was confirmed by Shenzhen Center for Disease Control and Prevention as human avian flu case and was then transferred to Intensive Care Unit (ICU). On the 83rd day of commence, the patients was healed and released from the hospital. The patient had no significant exposure to sick poultry or poultry that died from the illness before the onset of the disease. The patient and five family members lived together, but no family member was affected and no contact showed positive results for H5N1. A small food market with live poultry, which was under formal supervision and before illness the patient once visited, located near his apartment. Totally, 35 swabs from live
Pathogenic strains of Yersinia enterocolitica isolated from domestic dogs (Canis familiaris) belonging to farmers are of the same subtype as pathogenic Y. enterocolitica strains isolated from humans and may be a source of human infection in Jiangsu Province, China.
Wang, Xin; Cui, Zhigang; Wang, Hua; Tang, Liuying; Yang, Jinchuan; Gu, Ling; Jin, Dong; Luo, Longze; Qiu, Haiyan; Xiao, Yuchun; Xiong, Haiping; Kan, Biao; Xu, Jianguo; Jing, Huaiqi
We isolated 326 Yersinia enterocolitica strains from 5,919 specimens from patients with diarrhea at outpatient clinics, livestock, poultry, wild animals, insect vectors, food, and the environment in the cities of Nantong and Xuzhou in Jiangsu Province, China, from 2004 to 2008. The results showed that the 12 pathogenic strains were of the O:3 serotype. Six strains were isolated from domestic dogs (Canis familiaris) belonging to farmers and were found to be the primary carriers of pathogenic Y. enterocolitica strains, especially in Xuzhou. Pulsed-field gel electrophoresis analysis of the pathogenic strains from dogs belonging to farmers showed that they shared the same patterns as strains from diarrhea patients isolated in 1994. This indicates that the strains from domestic dogs have a close correlation with the strains causing human infections.
Vestergaard, Anna Lindeløv; Knudsen, Ulla Breth; Munk, Torben
The chronic female disease endometriosis causes debilitating pain and lowered fertility. The aetiology is unknown, but indications of an infectious agent are present. This study investigates the possible involvement of a pathogenic virus in endometriosis patients and controls. DNA was purified from......–10%). The virus prevalence was found to vary slightly when comparing the endometrium of healthy women and women with endometriosis. However, these were not significant differences, and no viruses were identified in endometriotic lesions. These results do not point towards any evidence that endometriosis is caused...
J. P. Mpatswenumugabo
Full Text Available A cross-sectional study was conducted from May 2016 to January 2017 in Rubavu and Nyabihu districts, Western Rwanda, aiming at estimating the prevalence of subclinical mastitis (SCM and identifying its causative bacteria. Management practices and milking procedures were recorded through a questionnaire. 123 crossbreed milking cows from 13 dairy farms were randomly selected and screened for SCM using California Mastitis Test (CMT. Composite CMT positive milk samples were processed for bacterial isolation and identification. The overall SCM prevalence at cow level was 50.4%. 68 bacterial isolates were identified by morphological and biochemical characteristics. They included, Coagulase Negative Staphylococci (51.5%, Staphylococcus aureus (20.6%, Streptococcus species (10.3%, Bacillus species (10.3%, Streptococcus agalactiae (5.8%, and Escherichia coli (1.5%. About 67.1% of the farmers checked for mastitis; of these, 58.9% relied on clinical signs and only 6.8% screened with CMT. Only 5.5% and 2.7% of the farmers tried to control mastitis using dry cow therapy and teat dips, respectively. Thus, to reduce the prevalence of SCM, farmers in the study area need to be trained on good milking practices, including regular use of teat dips, application of dry cow therapy, and SCM screening. This will improve their sales and their financial status.
Boudry, Pierre; Semenova, Ekaterina; Monot, Marc; Datsenko, Kirill A.; Lopatina, Anna; Sekulovic, Ognjen; Ospina-Bedoya, Maicol; Fortier, Louis-Charles; Severinov, Konstantin; Dupuy, Bruno
ABSTRACT Clostridium difficile is the cause of most frequently occurring nosocomial diarrhea worldwide. As an enteropathogen, C. difficile must be exposed to multiple exogenous genetic elements in bacteriophage-rich gut communities. CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) systems allow bacteria to adapt to foreign genetic invaders. Our recent data revealed active expression and processing of CRISPR RNAs from multiple type I-B CRISPR arrays in C. difficile reference strain 630. Here, we demonstrate active expression of CRISPR arrays in strain R20291, an epidemic C. difficile strain. Through genome sequencing and host range analysis of several new C. difficile phages and plasmid conjugation experiments, we provide evidence of defensive function of the CRISPR-Cas system in both C. difficile strains. We further demonstrate that C. difficile Cas proteins are capable of interference in a heterologous host, Escherichia coli. These data set the stage for mechanistic and physiological analyses of CRISPR-Cas-mediated interactions of important global human pathogen with its genetic parasites. PMID:26330515
Anastasia P Litvintseva
Full Text Available Most of the species of fungi that cause disease in mammals, including Cryptococcus neoformans var. grubii (serotype A, are exogenous and non-contagious. Cryptococcus neoformans var. grubii is associated worldwide with avian and arboreal habitats. This airborne, opportunistic pathogen is profoundly neurotropic and the leading cause of fungal meningitis. Patients with HIV/AIDS have been ravaged by cryptococcosis--an estimated one million new cases occur each year, and mortality approaches 50%. Using phylogenetic and population genetic analyses, we present evidence that C. neoformans var. grubii may have evolved from a diverse population in southern Africa. Our ecological studies support the hypothesis that a few of these strains acquired a new environmental reservoir, the excreta of feral pigeons (Columba livia, and were globally dispersed by the migration of birds and humans. This investigation also discovered a novel arboreal reservoir for highly diverse strains of C. neoformans var. grubii that are restricted to southern Africa, the mopane tree (Colophospermum mopane. This finding may have significant public health implications because these primal strains have optimal potential for evolution and because mopane trees contribute to the local economy as a source of timber, folkloric remedies and the edible mopane worm.
Murphin Kumar, Paskalis Sahaya; MubarakAli, Davoodbasha; Saratale, Rijuta Ganesh; Saratale, Ganesh Dattatraya; Pugazhendhi, Arivalagan; Gopalakrishnan, Kumar; Thajuddin, Nooruddin
Algae could offer a potential source of fine chemicals, pharmaceuticals and biofuels. In this study, a green synthesis of dispersed cuboidal gold nanoparticles (AuNPs) was achieved using red algae, Gelidium amansii reacted with HAuCl 4 . It was found to be 4-7 nm sized cubical nanoparticles with aspect ratio of 1.4 were synthesized using 0.5 mM of HAuCl 4 by HRSEM analysis. The crystalline planes (111), (200), (220), (311) and elemental signal of gold was observed by XRD and EDS respectively. The major constitutes, galactose and 3,6-anhydrogalactose in the alga played a critical role in the synthesis of crystalline AuNPs with cubical dimension. Further, the antibacterial potential of synthesized AuNPs was tested against human pathogens, Escherichia coli and Staphylococcus aureus. The synthesized AuNPs found biocompatible up to 100 ppm and high concentration showed an inhibition against cancer cell. This novel report could be helped to exploration of bioresources to material synthesis for the application of biosensor and biomedical application. Copyright © 2017 Elsevier Ltd. All rights reserved.
Whitney, M. M.; DeRosia-Banick, K.
Vibrio parahaemolyticus (Vp) is a marine bacterium that occurs naturally in brackish and saltwater environments and may be found in higher concentrations in the warmest months. Vp is a growing threat to producing safe seafood. Consumption of shellfish with high Vp levels can result in gastrointestinal human illnesses. Management response to Vp-related illness outbreaks includes closure of shellfish growing areas. Water quality observations, Vp measurements, and model forecasts are key components to effective management of shellfish growing areas. There is a clear need for observations within the growing area themselves. These areas are offshore of coastal stations and typically inshore of the observing system moorings. New field observations in Long Island Sound (LIS) shellfish growing areas are described and their agreement with high-resolution satellite sea surface temperature data is discussed. A new dataset of Vp concentrations in shellfish tissue is used to determine the LIS-specific Vp vs. temperature relationship following methods in the FDA pre-harvest Vp risk model. This information is combined with output from a high-resolution hydrodynamic model of LIS to make daily forecasts of Vp levels. The influence of river inflows, the role of heat waves, and predictions for future warmer climates are discussed. The key elements of this observational-modeling approach to pathogen forecasting are extendable to other coastal systems.
Yousaf, Sohail; Bulgari, Daniela; Bergna, Alessandro; Pancher, Michael; Quaglino, Fabio; Casati, Paola; Campisano, Andrea
Generally, plants are not considered as hosts for human and animal pathogens (HAP). The recent produce-associated outbreaks of food-borne diseases have drawn attention toward significant deficiencies in our understanding of the ecology of HAP, and their potential for interkingdom transfer. To examine the association of microorganisms classified as HAP with plants, we surveyed the presence and distribution of HAP bacterial taxa (henceforth HAPT, for brevity's sake) in the endosphere of grapevine (Vitis vinifera L.) both in the plant stems and leaves. An enrichment protocol was used on leaves to detect taxa with very low abundance in undisturbed tissues. We used pyrosequencing and phylogenetic analyses of the 16S rDNA gene. We identified several HAPT, and focused on four genera (Propionibacterium, Staphylococcus, Clostridium, and Burkholderia). The majority of the bacterial sequences in the genus Propionibacterium, from grapevine leaf and stem, were identified as P. acnes. Clostridia were detected in leaves and stems, but their number was much higher in leaves after enrichment. HAPT were indentified both in leaves and wood of grapevines. This depicts the ability of these taxa to be internalized within plant tissues and maintain their population levels in a variety of environments. Our analysis highlighted the presence of HAPT in the grapevine endosphere and unexpected occurrence of these bacterial taxa in this atypical environment.
Nielsen, L.K.; Cook, D.J.; Edwards, S.G.; Ray, R.V.
Fusarium head blight (FHB) caused by Fusarium and Microdochium species can significantly affect the yield of barley grain as well as the quality and safety of malt and beer. The present study provides new knowledge on the impacts of the FHB pathogen complex on the malting and brewing quality parameters of naturally infected barley. Quantitative real-time PCR and liquid chromatography double mass spectrometry were used to quantify the predominant FHB pathogens and Fusarium mycotoxins, respectively, in commercially grown UK malting barley samples collected between 2007 and 2011. The predominant Fusarium species identified across the years were F. poae, F. tricinctum and F. avenaceum. Microdochium majus was the predominant Microdochium species in 2007, 2008, 2010 and 2011 whilst Microdochium nivale predominated in 2009. Deoxynivalenol and zearalenone quantified in samples collected between 2007 and 2009 were associated with F. graminearum and F. culmorum, whilst HT-2 and T-2, and nivalenol in samples collected between 2010 and 2011 correlated positively with F. langsethiae and F. poae, respectively. Analysis of the regional distribution and yearly variation in samples from 2010 to 2011 showed significant differences in the composition of the FHB species complex. In most regions (Scotland, the South and North of England) the harvest in 2010 had higher concentrations of Fusarium spp. than in 2011, although no significant difference was observed in the Midlands between the two years. Microdochium DNA was significantly higher in 2011 and in the North of England and Scotland compared to the South or Midlands regions. Pathogens of the FHB complex impacted negatively on grain yield and quality parameters. Thousand grain weight of malting barley was affected significantly by M. nivale and M. majus whilst specific weight correlated negatively with F. avenaceum and F. graminearum. To determine the impact of sub-acute infections of the identified Fusarium and Microdochium
Andoh, Linda Aurelia; Ahmed, Shabana; Olsen, John Elmerdahl
Background Non-typhoidal Salmonella (NTS) is a public health problem worldwide and particularly in Africa with high disease burden. This study characterized Salmonella isolates from humans in Ghana to determine serovar distribution, phage types, and antimicrobial resistance. Further, the clonal...... relatedness among isolates was determined. Methods One hundred and thirty-seven Salmonella isolates (111 clinical and 26 public toilet) were characterized using standard serotyping, phage typing, and antimicrobial susceptibility testing methods. The molecular epidemiology of common serovars (Salmonella....... Fifty-eight (n = 58/112; 54.5%) strains were multi-resistant with low resistance to cephalosporins ceftazidime (8.0%), cefotaxime (4.5%), and cefoxitin (2.7%) with synergy to clavulanic acid indicating possible ESBLs. Isolates showed high resistance to trimethoprim (66.1%), tetracycline (61...
Lotfollahi, Lida; Chaharbalesh, Ardalan; Ahangarzadeh Rezaee, Mohammad; Hasani, Alka
Listeria monocytogenes is a foodborne pathogen causing listeriosis, which potentially affects all individuals, especially pregnant women and immunocompromised persons. The present study investigated the prevalence, antimicrobial susceptibility and serotypes distribution of the isolated L. monocytogenes from Iran. Twenty two (4.97%) of 442 human, food and livestock samples were found to be positive for L. monocytogenes. L. monocytogenes was identified in 8.8% of 125 human samples, 2.99% of 267 food and 6% of 50 livestock samples. The standard disk diffusion method and minimum inhibitory concentration (MIC) assay were used for antimicrobial susceptibility testing and multiplex PCR for serotyping. Among the 22 isolates tested, 6 (27.2%) displayed resistance to penicillin G, with all of the isolates and 2 (9%) of them showing intermediate susceptibility to clindamycin and rifampicin, respectively. According to the MIC assay, the rate of resistance to penicillin G was the same as that of disk diffusion method, but 16 (72.7%) of isolates showed intermediate susceptibility to clindamycin using E-test. In the multiplex PCR, 19 (86.4%) of isolates belonged to serotype 1/2c or 3c and the remaining 3 isolates were identified as (4b, 4d or 4e) and (1/2a or 3a), respectively. The occurrence of resistance to penicillin G, which can be used in the treatment of listeriosis, is very alarming and more prevalence of 1/2c serotype, in comparison to 3 other important ones (1/2a, 1/2b and 4b), in Iran has been reported for the first time. To the best of our knowledge, this is the first study showing the distribution of various serogroups of L. monocytogenes from human and livestock in Iran. Copyright © 2017 Elsevier Ltd. All rights reserved.
Gambotto, Andrea; Barratt-Boyes, Simon M.; de Jong, Menno D.; Neumann, Gabriele; Kawaoka, Yoshihiro
Highly pathogenic H5N1 influenza A viruses have spread relentlessly across the globe since 2003, and they are associated with widespread death in poultry, substantial economic loss to farmers, and reported infections of more than 300 people with a mortality rate of 60%. The high pathogenicity of
Duvaux, Ludovic; Shiller, Jason; Vandeputte, Patrick; Dug? de Bernonville, Thomas; Thornton, Christopher; Papon, Nicolas; Le Cam, Bruno; Bouchara, Jean-Philippe; Gastebois, Amandine
ABSTRACT The opportunistic fungal pathogen Scedosporium boydii is the most common Scedosporium species in French patients with cystic fibrosis. Here we present the first genome report for S.?boydii, providing a resource which may enable the elucidation of the pathogenic mechanisms in this species.
Kleespies, Regina G; Lim, Young Woon; Tkaczuk, Cezary
Ips sexdentatus (six-spined engraver beetle) from Austria and Poland were dissected and examined for the presence of pathogens. Specimens collected in Austria were found to contain the ascomycetous fungus Metschnikowia cf. typographi. Infection rates ranged from 3.6% to 26.8% at different...... collection sites. M. cf. typographi infected midguts were investigated by histological, ultrastructural and molecular techniques. Extraordinary ultrastructural details are shown, such as ascospores with bilateral flattened flanks resembling alar rims at both sides of their attenuating tube-like ends....... The eugregarine Gregarina typographi was diagnosed most frequently. Infection rates of all I. sexdentatus specimens ranged from 21.4% to 71.9% in Austria and 54.1% to 68.8% in Poland. Other entomopathogenic protists, bacteria, or viruses were not detected....
Van Damme, I.; De Zutter, L.; Jacxsens, L.
. enterocolitica in minced meat produced in industrial meat processing plants. The model described the production of minced pork starting from the contamination of pig carcasses with pathogenic Y. enterocolitica just before chilling. The endpoints of the assessment were (i) the proportion of 0.5 kg minced meat packages...... contamination and different decontamination procedures of carcasses have an important effect on the proportion of highly contaminated minced meat packages at the end of storage. The addition of pork cheeks and minimal quantities of tonsillar tissue into minced meat also had a large effect on the endpoint......This study aimed to evaluate the effect of different processing scenarios along the farm-to-fork chain on the contamination of minced pork with human pathogenic Y. enterocolitica. A modular process risk model (MPRM) was used to perform the assessment of the concentrations of pathogenic Y...
Abo-State, M.A.M.; El-Khatat, A.M.R.; El-Shahat, M.F.
Thirty three water and soil samples, from the urban and rural zones of El-Giza, Egypt, were used to evaluate the microbiological quality of soil, surface and groundwater samples. Total aerobic bacterial count of groundwater ranged from 2 x10 4 to 1. 2 x 10 7 CFU/ml, which were B. cereus (1 x10 2 - 1 x10 4 CFU/ml), Enterobacteriacea (1 x 10 2 - 2 x 10 6 CFU/ml), E.Coli (0 - 9 x 10 4 CFU/ml), Pseudomonas (9 x 10 2 - 3 x 10 6 CFU/ml), total Staph. (0 - 5.6 x 10 3 CFU/ml) and Staph. aureus (0 - 5 x10 3 CFU/ml). Meanwhile, surface water contained total aerobic bacterial count in the range of 1 x 10 5 -9 x 10 6 CFU/ml, which where l x10 2 - 4 x 10 3 CFU/ml B. cereus, 3.9 x 10''3 -1.6 x 10 6 CFU/ml Enterobacteriacea, 1 x 10 2 - 2.9 x 10 4 CFU/ml Ent. faecalis, 5 x 10 2 - 1.1 x 10 5 CFU/ml E. coli, 4.9 x 10 4 - 1.1 x 10 4 CFU/ml Pseudomonas, 3 x 10 2 - 4 x 10 4 CFU/ml total Staph. and 1 x 10 -1 x 10 4 CFU/ml Staph. aureus. Salmonella was detected in almost all surface water samples except in one sample. No Ent. faecalis, total Staph. and Staph. aureus or Salmonella had been detected in soil samples except in one sample, which recorded 4 x10 3 CFU/ml Ent. faecalis. Inactivation of pathogenic bacteria by heat treatment revealed that heating of water for 5 minutes at 100 degree C (boiling) got rid completely of pathogens except the spore forming Bacilli which still persisted
Pollari, Frank; Christidis, Tanya; Pintar, Katarina D M; Nesbitt, Andrea; Farber, Jeff; Lavoie, Marie-Claude; Gill, Alex; Kirsch, Penelope; Johnson, Roger P
Human infection with Escherichia coli O157:H7/NM has historically been associated with consumption of undercooked ground beef. The purpose of this paper is to investigate the correlation of the decline in E. coli O157:H7/NM infections in Canada with the introduction of control efforts in ground beef by industry. The human incidence of E. coli O157:H7/NM, prevalence in ground beef and interventions from 1996 to 2014 were analyzed. Pathogen prevalence data were obtained from federal government and industry surveillance and inspection/compliance programs. A survey of the largest ground beef producers in Canada was conducted to identify when interventions were implemented. The incidence of E. coli O157:H7/NM infections in Canada declined from ∼4 cases/100 000 to ∼1 case/100 000 from 2000 to 2010. Verotoxigenic Escherichia coli (VTEC) prevalence in ground beef sold at retail declined from about 30% around the year 2000 to <2% since 2012. Other measures of the prevalence of E. coli, VTEC, and E. coli O157:H7/NM in beef and ground beef also declined. The number and types of interventions implemented in the major beef processing establishments in Canada increased from 1996 to 2016. The observed decline in human illnesses and pathogen levels in relation to retail meats was associated with the introduction of control efforts by industry, federal and provincial/territorial governments, and the general population. Industry-led changes in beef processing along with the introduction of food safety policies, regulations, and public education have led to improved food safety in Canada.
Li, Wen-Chao; Ying, Meng; Gong, Peng-Tao; Li, Jian-Hua; Yang, Ju; Li, He; Zhang, Xi-Chen
Pentatrichomonas hominis is an anaerobic amitochondrial flagellated protist that primarily colonizes the large intestines of a number of species, including cats, dogs, nonhuman primates, and humans. The prevalence of this parasite in dogs, monkeys, and humans is, however, poorly understood. In this study, a total of 362 fecal samples including 252 dogs, 60 monkeys, and 50 humans from northern China were collected for an epidemiological survey of P. hominis infection.The average prevalence of P. hominis infection determined by nested PCR was 27.38% (69/252), 4.00% (2/50), and 46.67% (28/60) in dogs, humans, and monkeys, respectively. The prevalence was significantly higher in 6-month-old dogs (41.53%) and children (7.69%) than in older dogs (14.39%) and adults (0%) (P dogs, monkeys, and humans, especially in children and young dogs. Given the infection prevalence, P. hominis may pose a risk of zoonotic and anthroponotic transmission.
Berkowitz, R. D.; van't Wout, A. B.; Kootstra, N. A.; Moreno, M. E.; Linquist-Stepps, V. D.; Bare, C.; Stoddart, C. A.; Schuitemaker, H.; McCune, J. M.
Some individuals infected with only R5 strains of human immunodeficiency virus type 1 progress to AIDS as quickly as individuals harboring X4 strains. We determined that three R5 viruses were much less pathogenic than an X4 virus in SCID-hu Thy/Liv mice, suggesting that R5 virus-mediated rapid
Zaravinos, Apostolos; Bizakis, John; Spandidos, Demetrios A
This study aimed to investigate the prevalence of human papilloma virus (HPV), herpes simplex virus-1/-2 (HSV-1/-2), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), and human herpes virus-6/-7 (HHV-6/-7) in 23 human nasal polyps by applying PCR. Two types of control tissues were used: adjacent inferior/middle turbinates from the patients and inferior/middle turbinates from 13 patients undergoing nasal corrective surgery. EBV was the virus most frequently detected (35%), followed by HPV (13%), HSV-1 (9%), and CMV (4%). The CMV-positive polyp was simultaneously positive for HSV-1. HPV was also detected in the adjacent turbinates (4%) and the adjacent middle turbinate (4%) of one of the HPV-positive patients. EBV, HSV, and CMV were not detected in the adjacent turbinates of the EBV-, HSV- or CMV-positive patients. All mucosae were negative for the VZV, HHV-6, and HHV-7. This is the first study to deal with the involvement of a comparable group of viruses in human nasal polyposis. The findings support the theory that the presence of viral EBV markedly influences the pathogenesis of these benign nasal tumors. The low incidence of HPV detected confirms the hypothesis that HPV is correlated with infectious mucosal lesions to a lesser extent than it is with proliferative lesions, such as inverted papilloma. The low incidence of HSV-1 and CMV confirms that these two herpes viruses may play a minor role in the development of nasal polyposis. Double infection with HSV-1 and CMV may also play a minor, though causative, role in nasal polyp development. VZV and HHV-6/-7 do not appear to be involved in the pathogenesis of these mucosal lesions.
Full Text Available Viral infections caused by human bocaviruses 1-4 (HBoV1-4 are more complicated than previously believed. A retrospective, large-scale study was undertaken to explore the prevalence of HBoV1-4 in pediatric patients with various infectious diseases and delineate their phylogenetic characteristics.Clinical samples from four specimen types, including 4,941 respiratory, 2,239 cerebrospinal fluid (CSF, 2,619 serum, and 1,121 fecal specimens, collected from pediatric patients with various infectious diseases were screened for HBoV1-4. A 690-nt fragment in each specimen was then amplified and sequenced for phylogenetic analysis. Clinical characteristics of HBoV-positive patients with different specimen types available were evaluated.Approximately 1.2% of patients were confirmed as HBoV-positive, with the highest positive rate in patients with gastrointestinal infection (2.2%, followed by respiratory (1.65%, central nervous system (0.8%, and hematological infections (0.2%. A single genetic lineage of HBoV1 circulated among children over the 8-year period, while a new cluster of HBoV2, via intra-genotype recombination between HBoV2A and HBoV2B, was prevalent. Some patients had HBoV1-positive respiratory and serum specimens or fecal specimens. Several cases became HBoV1-positive following the appearance of respiratory infection, while several cases were positive for HBoV2 only in CSF and serum specimens, rather than respiratory specimens.A single genetic lineage of HBoV1 is speculated as a viral pathogen of respiratory infection and causes both comorbid infection and acute gastroenteritis. Additionally, a new cluster of HBoV2 is prevalent in China, which may infect the host through sites other than the respiratory tract.
Full Text Available Ashish Pathak1,2, Yogyata Marothi3, Vandana Kekre4, Kalpana Mahadik5, Ragini Macaden6, Cecilia Stålsby Lundborg11Division of Global Health, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden; 2Department of Pediatrics, 3Department of Microbiology, 4Department of Medicine, 5Department of Obstetrics and Gynecology, RD Gardi Medical College, Ujjain, India; 6St Johns Research Institute, Bangalore, IndiaBackground: Recent reports of the rapid evolution of bacterial resistance in India require urgent antibiotic stewardship programs. This study aimed to define the magnitude and pattern of resistance of bacterial pathogens to guide empirical therapy.Methods: We prospectively collected consecutive, clinically significant, and nonduplicate bacterial isolates from each patient from two hospitals in Ujjain, India. The antibiotic susceptibility of the bacteria was tested using a disc diffusion method as recommended by the Clinical and Laboratory Standards Institute.Results: A total of 716 pathogens were isolated from 2568 patients (median age, 25 years; range, 0 days to 92 years. Gram-negative infections were predominant (62%. The isolated pathogens included Staphylococcus aureus (n = 221; 31%, Escherichia coli (n = 149; 21%, Pseudomonas aeruginosa (n = 127; 18%, and Klebsiella pneumoniae (n = 107; 15%. Common diagnoses included abscesses (56%, urinary tract infections (14%, blood stream infections (10%, pneumonia (10%, and vaginal infections (10%. In E. coli isolates, 69% (95% confidence interval [CI] 61.6–76.6 were extended-spectrum β-lactamase (ESBL producers and 41% (95% CI 31.6–50.5 of K. pneumoniae isolates were ESBL producers. These isolates had a high resistance to fluoroquinolones and β-lactams, except for imipenem and piperacillin-tazobactam. Salmonella typhi remained sensitive to third-generation cephalosporins. Methicillin-resistant S. aureus (MRSA constituted 30% of all S. aureus isolates and showed resistance
Valibeigi, Behnaz; Ashraf, Mohamad Javad; Kerdegari, Narges; Safai, Akbar; Abedi, Elham; Khademi, Bijan; Azarpira, Negar
Statement of the Problem: Sinonasal papilloma (SNP) is a rare benign lesion characterized by high recurrence rate and malignant transformation. Purpose: This study aimed to investigate the prevalence of human papilloma virus (HPV) infection in these lesions in South of Iran. Materials and Method: In this cross sectional retrospective study, a total of 41 patients, 38 SNP and 3 SNP/Squamous cell carcinoma cases, from 2007 to 2014 were studied. Human papilloma virus (HPV) DNA detection w...
B.G. van den Hoogen (Bernadette); G.J.J. van Doornum (Gerard); J.C. Fockens (John); J.J. Cornelissen (Jan); W.E.Ph. Beyer (Walter); R. de Groot (Ronald); A.D.M.E. Osterhaus (Albert); R.A.M. Fouchier (Ron)
textabstractDuring a 17-month period, we performed retrospective analyses of the prevalence of and clinical symptoms associated with human metapneumovirus (hMPV) infection, among patients in a university hospital in The Netherlands. All available nasal-aspirate, throat-swab, sputum, and
Rôças, Isabela N; Siqueira, José F
Culture-independent studies have revealed a broad spectrum of oral bacterial taxa that may be associated with disease. This study investigated the prevalence of three new candidate oral pathogens: Prevotella baroniae, Prevotella multisaccharivorax, and as-yet-uncultivated Bacteroidetes oral clone X083 in primary endodontic infections using a devised culture-independent approach. Genomic DNA was isolated from samples taken from 52 teeth with different forms of apical periodontitis and used as template in a taxon-specific 16S rRNA gene-based nested polymerase chain reaction assay to determine the prevalence of the 3 target taxa. Bacteroidetes clone X083, P. baroniae, and P. multisaccharivorax were respectively detected in 81%, 43%, and 38% of the root canals of teeth associated with chronic apical periodontitis, in 60%, 40% and 40% of the canals of teeth with acute apical periodontitis, and in 14%, 24%, and 5% of the pus aspirates from acute apical abscesses. No targeted taxon was positively associated with abscesses or clinical symptoms. Overall, Bacteroidetes clone X083, P. baroniae, and P. multisaccharivorax were found in 50%, 35%, and 25% of the samples taken from primary endodontic infections, respectively. Findings confirmed that the two newly named species and the uncultivated phylotype targeted in this study are associated with different forms of apical periodontitis, and a pathogenetic or at least an ecologic role is suspected.
Lee, I. Russel; Chow, Eve W. L.; Morrow, Carl A.; Djordjevic, Julianne T.; Fraser, James A.
Proper regulation of metabolism is essential to maximizing fitness of organisms in their chosen environmental niche. Nitrogen metabolite repression is an example of a regulatory mechanism in fungi that enables preferential utilization of easily assimilated nitrogen sources, such as ammonium, to conserve resources. Here we provide genetic, transcriptional, and phenotypic evidence of nitrogen metabolite repression in the human pathogen Cryptococcus neoformans. In addition to loss of transcriptional activation of catabolic enzyme-encoding genes of the uric acid and proline assimilation pathways in the presence of ammonium, nitrogen metabolite repression also regulates the production of the virulence determinants capsule and melanin. Since GATA transcription factors are known to play a key role in nitrogen metabolite repression, bioinformatic analyses of the C. neoformans genome were undertaken and seven predicted GATA-type genes were identified. A screen of these deletion mutants revealed GAT1, encoding the only global transcription factor essential for utilization of a wide range of nitrogen sources, including uric acid, urea, and creatinine—three predominant nitrogen constituents found in the C. neoformans ecological niche. In addition to its evolutionarily conserved role in mediating nitrogen metabolite repression and controlling the expression of catabolic enzyme and permease-encoding genes, Gat1 also negatively regulates virulence traits, including infectious basidiospore production, melanin formation, and growth at high body temperature (39°–40°). Conversely, Gat1 positively regulates capsule production. A murine inhalation model of cryptococcosis revealed that the gat1Δ mutant is slightly more virulent than wild type, indicating that Gat1 plays a complex regulatory role during infection. PMID:21441208
Mukesh Kumar Singh
Full Text Available Objectives: The current investigation was carried out to determine the cytotoxic and the antimicrobial activities of methanolic extracts of Plumbago zeylanica. Methods: The stems, leaves, and whole plants were air dried and extracted with methanol by using a Soxhlet extractor for 72 hours at 55 - 60°C. The antimicrobial activities were determined from the zones of inhibition, which were measured by using the agar well diffusion method, and the cytotoxicity assays were performed using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay method. Results: The methanolic extracts of the stem and the leaves of Plumbago zeylanica were tested against six bacterial species and nine fungal species, and both extracts showed antimicrobial activity in a dose-dependent manner. The leaf extract of Plumbago zeylanica showed maximum antimicrobial activity against both Staphylococcus aureus sub sp aureus and Fusarium oxysporum. The stem extract was found to be more antimicrobial against the Pseudomonas aeruginosa and the Penicillium expansum species. MTT assays were used to test the cytotoxicity of the whole plant extract in the HCT-116 and the K-562 cell lines, and that extract was shown to have weak cytotoxicity in both cell lines. Conclusion: In the present study, the methanolic stem extracts of Plumbago zeylanica were found to possess remarkable antibacterial activities against many human and agricultural pathogens. The extracts were also found to possess significant antifungal activities, but the antifungal activities were less than the antibacterial activities. Finally, the extracts were found to have weak cytotoxicities in the HCT-116 and the K-562 cell lines.
Sattar, S A; Springthorpe, V S; Karim, Y; Loro, P
The chemical disinfection of virus-contaminated non-porous inanimate surfaces was investigated using coxsackievirus B3, adenovirus type 5, parainfluenza virus type 3 and coronavirus 229E as representatives of important nosocomial viral pathogens. A 10 microliter amount of the test virus, suspended in either faeces or mucin, was placed onto each stainless steel disk (about 1 cm in diameter) and the inoculum allowed to dry for 1 h under ambient conditions. Sixteen disinfectant formulations were selected for this study based on the findings of an earlier investigation with a human rotavirus. After 1 min exposure to 20 microliters of the disinfectant, the virus from the disks was immediately eluted into tryptose phosphate broth and plaque assayed. Using an efficacy criterion of a 3 log10 or greater reduction in virus infectivity titre and irrespective of the virus suspending medium, only the following five disinfectants proved to be effective against all the four viruses tested: (1) 2% glutaraldehyde normally used as an instrument soak, (2) a strongly alkaline mixture of 0.5% sodium o-benzyl-p-chlorophenate and 0.6% sodium lauryl sulphate, generally used as a domestic disinfectant cleaner for hard surfaces, (3) a 0.04% solution of a quaternary ammonium compound containing 7% hydrochloric acid, which is the basis of many toilet bowl cleaners, (4) chloramine T at a minimum free chlorine level of 3000 p.p.m. and (5) sodium hypochlorite at a minimum free chlorine concentration of 5000 p.p.m. Of those chemicals suitable for use as topical antiseptics, 70% ethanol alone or products containing at least 70% ethanol were ineffective only against coxsackievirus B3. These results emphasize the care needed in selecting chemical disinfectants for routine use in infection control.
Full Text Available BACKGROUND: Neisseria meningitidis is a naturally transformable, facultative pathogen colonizing the human nasopharynx. Here, we analyze on a genome-wide level the impact of recombination on gene-complement diversity and virulence evolution in N. meningitidis. We combined comparative genome hybridization using microarrays (mCGH and multilocus sequence typing (MLST of 29 meningococcal isolates with computational comparison of a subset of seven meningococcal genome sequences. PRINCIPAL FINDINGS: We found that lateral gene transfer of minimal mobile elements as well as prophages are major forces shaping meningococcal population structure. Extensive gene content comparison revealed novel associations of virulence with genetic elements besides the recently discovered meningococcal disease associated (MDA island. In particular, we identified an association of virulence with a recently described canonical genomic island termed IHT-E and a differential distribution of genes encoding RTX toxin- and two-partner secretion systems among hyperinvasive and non-hyperinvasive lineages. By computationally screening also the core genome for signs of recombination, we provided evidence that about 40% of the meningococcal core genes are affected by recombination primarily within metabolic genes as well as genes involved in DNA replication and repair. By comparison with the results of previous mCGH studies, our data indicated that genetic structuring as revealed by mCGH is stable over time and highly similar for isolates from different geographic origins. CONCLUSIONS: Recombination comprising lateral transfer of entire genes as well as homologous intragenic recombination has a profound impact on meningococcal population structure and genome composition. Our data support the hypothesis that meningococcal virulence is polygenic in nature and that differences in metabolism might contribute to virulence.
Jers, Carsten; Ravikumar, Vaishnavi; Lezyk, Mateusz Jakub
Protein lysine acetylation is recognized as an important reversible post translational modification in all domains of life. While its primary roles appear to reside in metabolic processes, lysine acetylation has also been implicated in regulating pathogenesis in bacteria. Several global lysine...... acetylome analyses have been carried out in various bacteria, but thus far there have been no reports of lysine acetylation taking place in the important human pathogen Vibrio cholerae. In this study, we analyzed the lysine acetylproteome of the human pathogen V. cholerae V52. By applying a combination...... in direct regulation of virulence in V. cholerae were acetylated. In conclusion, this is the first global protein lysine acetylome analysis of V. cholerae and should constitute a valuable resource for in-depth studies of the impact of lysine acetylation in pathogenesis and other cellular processes....
Hernádi, Katinka; Szalmás, Anita; Mogyorósi, Richárd; Czompa, Levente; Veress, György; Csoma, Eszter; Márton, Ildikó; Kónya, József
Apical periodontitis is a polymicrobial inflammation with a dominant flora of opportunistic Gram-negative bacteria; however, a pathogenic role of human herpesviruses such as Epstein-Barr virus (EBV) and human cytomegalovirus (HCMV) has been implicated recently. The aims of this study were to determine the prevalence, activity, and disease association of EBV and HCMV in apical periodontitis in an Eastern Hungarian population. Forty samples with apical periodontitis (17 symptomatic and 23 asymptomatic) and 40 healthy pulp controls were collected. EBV and HCMV prevalences were measured by polymerase chain reaction (PCR) detection of the viral DNA and viral activity was tested by reverse-transcription PCR amplification of viral messenger RNA. EBV DNA and EBNA-2 messenger RNA were found in apical periodontitis lesions at significantly (p apical lesions (10%) and controls (0%). The presence of EBV DNA in apical lesions was associated significantly with large (> or = 5 mm) lesion size (p = 0.02) but not with symptoms (p = 0.30). Symptomatic manifestation was significantly associated with the co-occurrence (odds ratio [OR], 8.80; 95% confidence interval [CI], 1.69-45.76) but not the sole occurrences of EBNA-2 messenger RNA (OR, 2.29; 95% CI, 0.48-11.06) and large lesion size (OR, 4.02; 95% CI, 0.81-19.89). EBV infection is a frequent event in apical periodontitis, whereas the involvement of HCMV still remains to be elucidated. This study showed that symptomatic manifestation was likely to occur if a large-sized apical periodontitis lesion is aggravated with active EBV infection. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
Jensen, Per M.; Christoffersen, Christian S.; Moutailler, Sara
Ixodes ricinus serves as vector for a range of microorganisms capable of causing clinical illness in humans. The microorganisms occur in the same vector populations and are generally affected by the same tick-host interactions. Still, the instars have different host preferences which should...
Jerlin Priya, Rajamanickam Rajkumar, Bakthasingh
Full Text Available Diabetes is considered to have reached epidemic proportions worldwide. The most distressing complication of diabetes is foot ulcer and is the major cause of lower limb amputation. Hence, they require a prolonged hospital stay to combat more serious complications like gangrene and lower limb amputation. Early detection and prompt treatment help in alleviating the ulceration. Methods: The present study was conducted among 50 diabetes patients. Study subjects were selected using non probability purposive sampling technique. Pus samples were collected by using sterile swabs in a sterile manner from the ulcerated area. The wounds are washed vigorously with normal saline solution before collection of specimen. The specimens were transported immediately to the laboratory for culture. The clinical specimens were first screened microscopically by Gram’s stain, and then cultured on blood agar (aerobically and an aerobically, MacConkey agar and Robertson cooked meat broth for 48 hours at 37°C in 5-10 percent CO2 and bacteria’s were isolated. Results: The socio demographic profile of the present study reveals that males were predominant among the study population. Type II diabetes was more common, majority of study subjects are suffering from diabetes for more than 5 years and are treated with oral hypoglycemic drugs. The wound size was ≤ 2cms in majority of study subjects. The bacteriological profile of diabetic ulcer reveals that a majority of 23 (46% had growth of Staphylococcus aureus and 19 (38% had growth of klebsiella and a minimum of 6 (12% and 2 (4% had grown of Pseudomonas and Staphylococcus albus. Conclusion: Early detection of these bacterial pathogens helps to minimize the disease progress.
Feagins, A. R.; Opriessnig, T.; Huang, Y. W.; Halbur, P. G.; Meng, X. J.
SUMMARY Hepatitis E virus (HEV) is an important pathogen. The animal strain of HEV, swine HEV, is related to human HEV. The genotype 3 swine HEV infected humans and genotype 3 human HEV infected pigs. The genotype 4 swine and human HEV strains are genetically related, but it is unknown whether genotype 4 human HEV can infect pigs. A swine bioassay was utilized in this study to determine whether genotype 4 human HEV can infect pigs. Fifteen, 4-week-old, specific-pathogen-free pigs were divided into 3 groups of 5 each. Group 1 pigs were each inoculated intravenously with PBS buffer as negative controls, group 2 pigs similarly with genotype 3 human HEV (strain US-2), and group 3 pigs similarly with genotype 4 human HEV (strain TW6196E). Serum and fecal samples were collected at 0, 7, 14, 21, 28, 35, 42, 49, and 56 days postinoculation (dpi) and tested for evidence of HEV infection. All pigs were necropsied at 56 dpi. As expected, the negative control pigs remained negative. The positive control pigs inoculated with genotype 3 human HEV all became infected as evidenced by detection of HEV antibodies, viremia and fecal virus shedding. All five pigs in group 3 inoculated with genotype 4 human HEV also became infected: fecal virus shedding and viremia were detected variably from 7 to 56 dpi, and seroconversion occurred by 28 dpi. The data indicated that genotype 4 human HEV has an expanded host range, and the results have important implications for understanding the natural history and zoonosis of HEV. PMID:18551597
Brambila-Tapia, Aniel Jessica Leticia; Poot-Hernández, Augusto Cesar; Garcia-Guevara, Jose Fernando; Rodríguez-Vázquez, Katya
To date, a few works have performed a correlation of metabolic variables in bacteria; however specific correlations with these variables have not been reported. In this work, we included 36 human pathogenic bacteria and 18 non- or less-pathogenic-related bacteria and obtained all metabolic variables, including enzymes, metabolic pathways, enzymatic steps and specific metabolic pathways, and enzymatic steps of particular metabolic processes, from a reliable metabolic database (KEGG). Then, we correlated the number of the open reading frames (ORF) with these variables and with the proportions of these variables, and we observed a negative correlation with the proportion of enzymes (r = -0.506, p < 0.0001), metabolic pathways (r = -0.871, p < 00.0001), enzymatic reactions (r = -0.749, p < 00.0001), and with the proportions of central metabolism variables as well as a positive correlation with the proportions of multistep reactions (r = 0.650, p < 00.0001) and secondary metabolism variables. The proportion of multifunctional reactions (r: -0.114, p = 0.41) and the proportion of enzymatic steps (r: -0.205, p = 0.14) did not present a significant correlation. These correlations indicate that as the size of a genome (measured in the number of ORFs) increases, the proportion of genes that encode enzymes significantly diminishes (especially those related to central metabolism), suggesting that when essential metabolic pathways are complete, an increase in the number of ORFs does not require a similar increase in the metabolic pathways and enzymes, but only a slight increase is sufficient to cope with a large genome.
Wiedner, Susan D; Burnum, Kristin E; Pederson, LeeAnna M; Anderson, Lindsey N; Fortuin, Suereta; Chauvigné-Hines, Lacie M; Shukla, Anil K; Ansong, Charles; Panisko, Ellen A; Smith, Richard D; Wright, Aaron T
Environmental adaptability is critical for survival of the fungal human pathogen Aspergillus fumigatus in the immunocompromised host lung. We hypothesized that exposure of the fungal pathogen to human serum would lead to significant alterations to the organism's physiology, including metabolic activity and stress response. Shifts in functional pathway and corresponding enzyme reactivity of A. fumigatus upon exposure to the human host may represent much needed prognostic indicators of fungal infection. To address this, we employed a multiplexed activity-based protein profiling (ABPP) approach coupled to quantitative mass spectrometry-based proteomics to measure broad enzyme reactivity of the fungus cultured with and without human serum. ABPP showed a shift from aerobic respiration to ethanol fermentation and utilization over time in the presence of human serum, which was not observed in serum-free culture. Our approach provides direct insight into this pathogen's ability to survive, adapt, and proliferate. Additionally, our multiplexed ABPP approach captured a broad swath of enzyme reactivity and functional pathways and provides a method for rapid assessment of the A. fumigatus response to external stimuli.
Wiedner, Susan D.; Burnum, Kristin E.; Pederson, LeeAnna M.; Anderson, Lindsey N.; Fortuin, Suereta; Chauvigné-Hines, Lacie M.; Shukla, Anil K.; Ansong, Charles; Panisko, Ellen A.; Smith, Richard D.; Wright, Aaron T.
Environmental adaptability is critical for survival of the fungal human pathogen Aspergillus fumigatus in the immunocompromised host lung. We hypothesized that exposure of the fungal pathogen to human serum would lead to significant alterations to the organism's physiology, including metabolic activity and stress response. Shifts in functional pathway and corresponding enzyme reactivity of A. fumigatus upon exposure to the human host may represent much needed prognostic indicators of fungal infection. To address this, we employed a multiplexed activity-based protein profiling (ABPP) approach coupled to quantitative mass spectrometry-based proteomics to measure broad enzyme reactivity of the fungus cultured with and without human serum. ABPP showed a shift from aerobic respiration to ethanol fermentation and utilization over time in the presence of human serum, which was not observed in serum-free culture. Our approach provides direct insight into this pathogen's ability to survive, adapt, and proliferate. Additionally, our multiplexed ABPP approach captured a broad swath of enzyme reactivity and functional pathways and provides a method for rapid assessment of the A. fumigatus response to external stimuli. PMID:22865858
Hoen, Anne Gatewood; Rollend, Lindsay G; Papero, Michele A; Carroll, John F; Daniels, Thomas J; Mather, Thomas N; Schulze, Terry L; Stafford, Kirby C; Fish, Durland
We evaluated the effects of tick control by acaricide self-treatment of white-tailed deer on the infection prevalence and entomologic risk for three Ixodes scapularis-borne bacteria in host-seeking ticks. Ticks were collected from vegetation in areas treated with the "4-Poster" device and from control areas over a 6-year period in five geographically diverse study locations in the Northeastern United States and tested for infection with two known agents of human disease, Borrelia burgdorferi and Anaplasma phagocytophilum, and for a novel relapsing fever-group spirochete related to Borrelia miyamotoi. Overall, 38.2% of adults and 12.5% of nymphs were infected with B. burgdorferi; 8.5% of adults and 4.2% of nymphs were infected with A. phagocytophilum; and 1.9% of adults and 0.8% of nymphs were infected with B. miyamotoi. In most cases, treatment with the 4-Poster device was not associated with changes in the prevalence of infection with any of these three microorganisms among nymphal or adult ticks. However, the density of nymphs infected with B. burgdorferi, and consequently the entomologic risk for Lyme disease, was reduced overall by 68% in treated areas compared to control areas among the five study sites at the end of the study. The frequency of bacterial coinfections in ticks was generally equal to the product of the proportion of ticks infected with a single bacterium, indicating that enzootic maintenance of these pathogens is independent. We conclude that controlling ticks on deer by self-application of acaricide results in an overall decrease in the human risk for exposure to these three bacterial agents, which is due solely to a reduction in tick density.
Lam, J U H; Rebolj, M; Ejegod, D M
The Copenhagen Self-Sampling Initiative (CSi) has shown how human papillomavirus (HPV)-based self-sampling can be used to increase screening participation among 23,632 nonattenders in the Capital Region of Denmark. In this study, we describe HPV prevalence and genotype frequency in 4,824 self...... study, which had been undertaken in the same screening laboratory. Nonattenders had an HPV prevalence of 11.3% as determined by the CLART assay, which was lower than that for women from the Horizon study (18.5%). One-third of the CSi women who tested HPV positive by self-sampling tested HPV negative...
Sobel Leonard, Ashley; Weissman, Daniel B; Greenbaum, Benjamin; Ghedin, Elodie; Koelle, Katia
advances in sequencing technology have enabled bottleneck size estimation from pathogen genetic data, although there is not yet a consistency in the statistical methods used. Here, we introduce a new approach to infer the bottleneck size that accounts for variant identification protocols and noise during pathogen replication. We show that failing to account for these factors leads to an underestimation of bottleneck sizes. We apply this method to an existing data set of human influenza virus infections, showing that transmission is governed by a loose, but highly variable, transmission bottleneck whose size is positively associated with the severity of infection of the donor. Beyond advancing our understanding of influenza virus transmission, we hope that this work will provide a standardized statistical approach for bottleneck size estimation for viral pathogens. Copyright © 2017 Sobel Leonard et al.
Van Damme, Inge; Berkvens, Dirk; De Zutter, Lieven
The objective of this study was to determine the effect of sampling (swab samples compared to destructive samples) on isolation rates of human pathogenic Yersinia enterocolitica from pig tonsils. Moreover, the relative efficiency of different rapid, routinely applicable isolation methods was evaluated. Therefore, swab and destructive samples from tonsils of 120 pigs at slaughter were analyzed in parallel using direct plating and different enrichment methods. Salmonella-Shigella-desoxycholate-calcium chloride (SSDC) agar, cefsulodin-irgasan-novobiocin (CIN) agar, and Yersinia enterocolitica chromogenic medium (YeCM) were used as selective agar media. For enrichment, irgasan-ticarcillin-potassium chlorate (ITC) broth and peptone-sorbitol-bile (PSB) broth were incubated at 25°C for 48 h. Overall, 55 tonsils (45.8%) were positive for Y. enterocolitica bioserotype 4/O:3. Recovery was significantly higher using the destructive method compared to the swabbing method. Direct plating resulted in 47 and 28 Y. enterocolitica-positive destructive and swab samples, respectively. Alkali treatment of PSB and ITC enrichment broths significantly increased recovery of pathogenic Y. enterocolitica from destructive tonsil samples. The performance of YeCM for qualitative and quantitative isolation of pathogenic Y. enterocolitica from pig tonsils was equal to SSDC and CIN. In conclusion, direct plating and ISO 10273: 2003 with minor modifications are suitable and rapid methods for isolation of pathogenic Y. enterocolitica from destructive tonsil samples.
Mallappa Kumara Swamy
Full Text Available A wide range of medicinal and aromatic plants (MAPs have been explored for their essential oils in the past few decades. Essential oils are complex volatile compounds, synthesized naturally in different plant parts during the process of secondary metabolism. Essential oils have great potential in the field of biomedicine as they effectively destroy several bacterial, fungal, and viral pathogens. The presence of different types of aldehydes, phenolics, terpenes, and other antimicrobial compounds means that the essential oils are effective against a diverse range of pathogens. The reactivity of essential oil depends upon the nature, composition, and orientation of its functional groups. The aim of this article is to review the antimicrobial potential of essential oils secreted from MAPs and their possible mechanisms of action against human pathogens. This comprehensive review will benefit researchers who wish to explore the potential of essential oils in the development of novel broad-spectrum key molecules against a broad range of drug-resistant pathogenic microbes.
A wide range of medicinal and aromatic plants (MAPs) have been explored for their essential oils in the past few decades. Essential oils are complex volatile compounds, synthesized naturally in different plant parts during the process of secondary metabolism. Essential oils have great potential in the field of biomedicine as they effectively destroy several bacterial, fungal, and viral pathogens. The presence of different types of aldehydes, phenolics, terpenes, and other antimicrobial compounds means that the essential oils are effective against a diverse range of pathogens. The reactivity of essential oil depends upon the nature, composition, and orientation of its functional groups. The aim of this article is to review the antimicrobial potential of essential oils secreted from MAPs and their possible mechanisms of action against human pathogens. This comprehensive review will benefit researchers who wish to explore the potential of essential oils in the development of novel broad-spectrum key molecules against a broad range of drug-resistant pathogenic microbes. PMID:28090211
Kamyar Mansori; Erfan Ayubi; Fatemeh Khosravi Shadmani; Shiva Mansouri Hanis; Somayeh Khazaei; Mohadeseh Sani; Yousef Moradi; Salman Khazaei; Abolfazl Mohammadbeigi
Background: HIV/AIDS is one of greatest global public health concerns today due to the high incidence, prevalence and mortality rates. The aim of this research was investigate and estimate the global HIV/AIDS mortality, prevalence and incidence rates, and explore their associations with the Human Development Index. Methods: The global age-standardized rates of mortality, prevalence and incidence of HIV/AIDS were obtained from the UNAIDS for different countries in 2015. The human developm...
Full Text Available To assess fecal pollution in coastal waters, current monitoring is reliant on culture-based enumeration of bacterial indicators, which does not account for the presence of viable but non-culturable or sediment-associated micro-organisms, preventing effective quantitative microbial risk assessment (QMRA. Seasonal variability in viable but non-culturable or sediment-associated bacteria challenge the use of fecal indicator organisms (FIOs for water monitoring. We evaluated seasonal changes in FIOs and human enteric pathogen abundance in water and sediments from the Ribble and Conwy estuaries in the UK. Sediments possessed greater bacterial abundance than the overlying water column, however, key pathogenic species (Shigella spp., Campylobacter jejuni, Salmonella spp., hepatitis A virus, hepatitis E virus and norovirus GI and GII were not detected in sediments. Salmonella was detected in low levels in the Conwy water in spring/summer and norovirus GII was detected in the Ribble water in winter. The abundance of E. coli and Enterococcus spp. quantified by culture-based methods, rarely matched the abundance of these species when measured by qPCR. The discrepancy between these methods was greatest in winter at both estuaries, due to low CFU's, coupled with higher gene copies (GC. Temperature accounted for 60% the variability in bacterial abundance in water in autumn, whilst in winter salinity explained 15% of the variance. Relationships between bacterial indicators/pathogens and physicochemical variables were inconsistent in sediments, no single indicator adequately described occurrence of all bacterial indicators/pathogens. However, important variables included grain size, porosity, clay content and concentrations of Zn, K, and Al. Sediments with greater organic matter content and lower porosity harbored a greater proportion of non-culturable bacteria (including dead cells and extracellular DNA in winter. Here, we show the link between physicochemical
Frager, Shalom Z; Chrisman, Cara J; Shakked, Rachel; Casadevall, Arturo
A fundamental question in the field of medical mycology is the origin of virulence in those fungal pathogens acquired directly from the environment. In recent years, it was proposed that the virulence of certain environmental animal-pathogenic microbes, such as Cryptococcus neoformans, originated from selection pressures caused by species-specific predation. In this study, we analyzed the interaction of C. neoformans with three Paramecium spp., all of which are ciliated mobile protists. In contrast to the interaction with amoebae, some Paramecium spp. rapidly ingested C. neoformans and killed the fungus. This study establishes yet another type of protist-fungal interaction supporting the notion that animal-pathogenic fungi in the environment are under constant selection by predation.
Grimbaldeston, Michele A; Skov, Lone; Finlay-Jones, John J
eliminate them. Studies in a range of inbred mouse strains as well as mast cell-depleted mice reconstituted with mast cell precursors support a functional link between histamine-staining dermal mast cells and the extent of susceptibility to UVB-induced systemic immunomodulation. Humans, like mouse strains......, display variations in dermal mast cell prevalence. In a study of Danish and South Australian BCC patients and control subjects, one 4-mm punch biopsy of non-sun-exposed buttock skin was sampled from each participant. This skin site was investigated to avoid any changes in mast cell prevalence caused...... by sun exposure. Two sections (4 microm) per biopsy were immunohistochemically stained for detection of histamine-containing dermal mast cells. Computer-generated image analysis evaluated dermal mast cell prevalence in both sections by quantifying the total number of mast cells according to the total...
Hanabara, Yutaro; Ueda, Yutaka
A rapid, simple method for detecting foodborne pathogenic bacteria in human feces is greatly needed. Here, we examined the efficacy of a method that employs a combination of a commercial PCR master mix, which is insensitive to PCR inhibitors, and a DNA extraction method which used sodium dodecyl benzene sulfonate (SDBS), and Tween 20 to counteract the inhibitory effects of SDBS on the PCR assay. This method could detect the target genes (stx1 and stx2 of enterohemorrhagic Escherichia coli, invA of Salmonella Enteritidis, tdh of Vibrio parahaemolyticus, gyrA of Campylobacter jejuni, ceuE of Campylobacter coli, SEA of Staphylococcus aureus, ces of Bacillus cereus, and cpe of Clostridium perfringens) in a fecal suspension containing 1.0 × 10 1 to 1.0 × 10 3 CFU/ml. Furthermore, the assay was neither inhibited nor influenced by individual differences among the fecal samples of 10 subjects or fecal concentration (40-160 mg/ml in the fecal suspension). When we attempted to detect the genes of pathogenic bacteria in 4 actual clinical cases, we found that this method was more sensitive than standard culture method. These results showed that this assay is a rapid, simple detection method for foodborne pathogenic bacteria in human feces.
Mozhgani, Sayed-Hamidreza; Zarei Ghobadi, Mohadeseh; Moeini, Sina; Pakzad, Reza; Kananizadeh, Pegah; Behzadian, Farida
This systematic review and meta-analysis was conducted to consolidate the information on the prevalence of the human influenza virus, including H1N1 and H3N2 as well as B-type influenza across Iran from 2000 to December 2016. The literature search was based on keywords including "influenza and Iran", "human influenza", "prevalence", "relative frequency", "incidence", and "drug" in MEDLINE (PubMed), Web of Science, Scopus, ScienceDirect, the Iranian Research Institute for Information Science and Technology (IranDoc), the Regional Information Centre for Science & Technology (RICeST), and the Scientific Information Database (SID). The literature search revealed 25 prevalence and seven drug resistance studies. In order to investigate the publication bias among studies, funnel plots and Egger's test were used. Additionally, the statistical tests of I 2 , Chi 2 , and Tau 2 were computed, and the results were visualized with forest plots. A high level of I 2 and Chi 2 were obtained among studies, which are representative of the high variation and remarkable heterogeneity between studies. This may be because of various methodologies applied in the studies such as study design, age groups, and different populations. The prevalence of influenza H1N1, H3N2, and B in Iran have not yet been well evaluated. The heterogeneity among studies reveals that more attention should be paid to considering various factors, including gender, population size, and underlying conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.
Gallegos-Bolaños, Jazbet; Rivera-Domínguez, Jessica Alejandra; Presno-Bernal, José Miguel; Cervantes-Villagrana, Rodolfo Daniel
Human papillomavirus (HPV) is associated with the genesis of cervical carcinoma. The co-infection among HPV genotypes is frequent, but the clinical significance is controversial; in Mexico, the prevalence and pattern of co-infection differ depending on the geographic area of study. We analyzed the mono- and co-infection prevalence of multiple HPV genotypes, as well as preferential interactions among them in a Mexico City sample population. This study was designed as a retrospective cohort study. Cervical cytology samples from 1163 women and 166 urethral scraping samples of men were analyzed between 2010 and 2012. The detection of HPV infection was performed using the hybrid capture and the genotyping was by PCR (HPV 6, 11, 16, 18, 30, 31, 33, 35, 45, 51, and 52). 36% of women were HPV-positive and the most prevalent genotypes were HPV 51, 52, 16, and 33 (42, 38, 37, and 34%, respectively). The prevalence of co-infection was higher (75.37%) than mono-infection in women HPV positives. All genotypes were co-infected with HPV 16, but the co-infection with 51-52 genotypes was the most frequent combination in all cases. The co-infection was very common; each HPV genotype showed different preferences for co-infection with other genotypes, HPV 51-52 co-infection was the most frequent. The HPV 16, 33, 51 and 52 were the most prevalent and are a public health concern to the Mexican population.
Adams, Andrea J; Pessier, Allan P; Briggs, Cheryl J
As extinctions continue across the globe, conservation biologists are turning to species reintroduction programs as one optimistic tool for addressing the biodiversity crisis. For repatriation to become a viable strategy, fundamental prerequisites include determining the causes of declines and assessing whether the causes persist in the environment. Invasive species-especially pathogens-are an increasingly significant factor contributing to biodiversity loss. We hypothesized that Batrachochytrium dendrobatidis (Bd), the causative agent of the deadly amphibian disease chytridiomycosis, was important in the rapid (herpetological experts, analysis of archived field notes and museum specimen collections, and field sampling of the extant amphibian assemblage to examine (1) historical relative abundance of R. boylii ; (2) potential causes of R. boylii declines; and (3) historical and contemporary prevalence of Bd. We found that R. boylii were relatively abundant prior to their rapid extirpation, and an increase in Bd prevalence coincided with R. boylii declines during a time of rapid change in the region, wherein backcountry recreation, urban development, and the amphibian pet trade were all on the rise. In addition, extreme flooding during the winter of 1969 coincided with localized extirpations in R. boylii populations observed by interview respondents. We conclude that Bd likely played an important role in the rapid extirpation of R. boylii from southern California and that multiple natural and anthropogenic factors may have worked in concert to make this possible in a relatively short period of time. This study emphasizes the importance of recognizing historical ecological contexts in making future management and reintroduction decisions.
Forslund, Anita; Plauborg, Finn; Andersen, Mathias Neumann
The risk for contamination of potatoes and groundwater through subsurface drip irrigation with low quality water was explored in 30 large-scale lysimeters containing repacked coarse sand and sandy loam soils. The human pathogens, Salmonella Senftenberg, Campylobacter jejuni and Escherichia coli O......, phage 28B was detected in low concentrations (2 pfu ml1) in leachate from both sandy loam soil and coarse sand lysimeters. After 27 days, phage 28B continued to be present in similar concentrations in leachate from lysimeters containing coarse sand, while no phage were found in lysimeters with sandy....... The findings of bacterial pathogens and phage 28 on all potato samples suggest that the main risk associated with subsurface drip irrigation with low quality water is faecal contamination of root crops, in particular those consumed raw....
Chen, Mei-Feng; Shih, Shin-Ru
Enterovirus 71 (EV71) has caused large-scale epidemics with neurological complications in the Asia-Pacific region. The C4a and B5 strains are the two major genotypes circulating in many countries recently. This study used a new protocol, a motor coordination task, to assess the differential pathogenicity of C4a and B5 strains in human SCARB2 transgenic mice. We found that the pathogenicity of C4a viruses was more severe than that of B5 viruses. Moreover, we discovered that an increased level of monocyte chemoattractant protein-1 was positively correlated with severely deficient motor function. This study provides a new method for evaluating EV71 infection in mice and distinguishing the severity of the symptoms caused by different clinical strains, which would contribute to studies of pathogenesis and development of vaccines and antivirals in EV71 infections.
Oliver, Stephen P; Murinda, Shelton E; Jayarao, Bhushan M
Antibiotics have saved millions of human lives, and their use has contributed significantly to improving human and animal health and well-being. Use of antibiotics in food-producing animals has resulted in healthier, more productive animals; lower disease incidence and reduced morbidity and mortality in humans and animals; and production of abundant quantities of nutritious, high-quality, and low-cost food for human consumption. In spite of these benefits, there is considerable concern from public health, food safety, and regulatory perspectives about the use of antimicrobials in food-producing animals. Over the last two decades, development of antimicrobial resistance resulting from agricultural use of antibiotics that could impact treatment of diseases affecting the human population that require antibiotic intervention has become a significant global public health concern. In the present review, we focus on antibiotic use in lactating and nonlactating cows in U.S. dairy herds, and address four key questions: (1) Are science-based data available to demonstrate antimicrobial resistance in veterinary pathogens that cause disease in dairy cows associated with use of antibiotics in adult dairy cows? (2) Are science-based data available to demonstrate that antimicrobial resistance in veterinary pathogens that cause disease in adult dairy cows impacts pathogens that cause disease in humans? (3) Does antimicrobial resistance impact the outcome of therapy? (4) Are antibiotics used prudently in the dairy industry? On the basis of this review, we conclude that scientific evidence does not support widespread, emerging resistance among pathogens isolated from dairy cows to antibacterial drugs even though many of these antibiotics have been used in the dairy industry for treatment and prevention of disease for several decades. However, it is clear that use of antibiotics in adult dairy cows and other food-producing animals does contribute to increased antimicrobial resistance
Full Text Available Immunity and cellular metabolism are tightly interconnected but it is not clear whether different pathogens elicit specific metabolic responses. To address this issue, we studied differential metabolic regulation in peripheral blood mononuclear cells (PBMCs of healthy volunteers challenged by Candida albicans, Borrelia burgdorferi, lipopolysaccharide, and Mycobacterium tuberculosis in vitro. By integrating gene expression data of stimulated PBMCs of healthy individuals with the KEGG pathways, we identified both common and pathogen-specific regulated pathways depending on the time of incubation. At 4 h of incubation, pathogenic agents inhibited expression of genes involved in both the glycolysis and oxidative phosphorylation pathways. In contrast, at 24 h of incubation, particularly glycolysis was enhanced while genes involved in oxidative phosphorylation remained unaltered in the PBMCs. In general, differential gene expression was less pronounced at 4 h compared to 24 h of incubation. KEGG pathway analysis allowed differentiation between effects induced by Candida and bacterial stimuli. Application of genome-scale metabolic model further generated a Candida-specific set of 103 reporter metabolites (e.g., desmosterol that might serve as biomarkers discriminating Candida-stimulated PBMCs from bacteria-stimuated PBMCs. Our analysis also identified a set of 49 metabolites that allowed discrimination between the effects of Borrelia burgdorferi, lipopolysaccharide and Mycobacterium tuberculosis. We conclude that analysis of pathogen-induced effects on PBMCs by a combination of KEGG pathways and genome-scale metabolic model provides deep insight in the metabolic changes coupled to host defense.
Koning, Nathalie; Kessen, Sabine F M; Van Der Voorn, J Patrick; Appelmelk, Ben J; Jeurink, Prescilla V; Knippels, Leon M J; Garssen, Johan; Van Kooyk, Yvette
Beneficial effects of breastfeeding are well-recognized and include both immediate neonatal protection against pathogens and long-term protection against allergies and autoimmune diseases. Although several proteins have been identified to have anti-viral or anti-bacterial effects like secretory IgA
Carlson, John Andrew; Rady, Peter; Kadam, Pooja; He, Qin; Simonette, Rebecca; Tyring, Stephen
Elephantiasis is considered a cutaneous region of immune deficiency with cobblestone-like surface caused by a wart-like eruption. Verrucosis is a diffuse human papillomavirus (HPV) infection linked to immunodeficiency disorders. The objective of this study was to examine the prevalence of HPV infection in lymphedema and its pathogenic role in elephantiasis. A retrospective case-control study was performed examining lymphedematous skin and controls of peritumoral normal skin. HPV infection was evaluated at the DNA, protein, and histopathologic levels by polymerase chain reaction, immunohistochemistry, and light microscopy, respectively. Overall, 540 HPV DNAs were detected in 120 of 122 cutaneous samples (median 4 HPV DNAs per sample, range 0-9). Compared with controls, no differences existed in type or number of HPVs identified. Instead, a diverse spectrum of HPV-related histopathologies were evident, likely reflecting the multiplicity of HPV genotypes detected. Most notably, increasing histopathologic lymphedema stage significantly correlated with markers of productive HPV infection such as altered keratohyaline granules and HPV L1 capsid expression. Limitations of this study are the absence of normal skin controls not associated with neoplasia or subclinical lymphedema, and lack of assessment of HPV copy number per keratinocyte infected. In conclusion, productive HPV infection, not HPV type or numbers detected, distinguished lymphedematous skin from controls. These findings support the theory that lymphedema creates a region of depressed immunity that permits productive HPV infection, manifested clinically by diffuse papillomatosis, characteristic of elephantiasis.
Full Text Available Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS is an emerging technique for the rapid and high-throughput identification of microorganisms. There remains a dearth of studies in which a large number of pathogenic microorganisms from a particular country or region are utilized for systematic analyses. In this study, peptide mass reference spectra (PMRS were constructed and evaluated from numerous human pathogens (a total of 1019 strains from 94 species, including enteric (46 species, respiratory (21 species, zoonotic (17 species, and nosocomial pathogens (10 species, using a MALDI-TOF MS Biotyper system (MBS. The PMRS for 380 strains of 52 species were new contributions to the original reference database (ORD. Compared with the ORD, the new reference database (NRD allowed for 28.2% (from 71.5% to 99.7% and 42.3% (from 51.3% to 93.6% improvements in identification at the genus and species levels, respectively. Misidentification rates were 91.7% and 57.1% lower with the NRD than with the ORD for genus and species identification, respectively. Eight genera and 25 species were misidentified. For genera and species that are challenging to accurately identify, identification results must be manually determined and adjusted in accordance with the database parameters. Through augmentation, the MBS demonstrated a high identification accuracy and specificity for human pathogenic microorganisms. This study sought to provide theoretical guidance for using PMRS databases in various fields, such as clinical diagnosis and treatment, disease control, quality assurance, and food safety inspection.
Barker, S Fiona; Packer, Michael; Scales, Peter J; Gray, Stephen; Snape, Ian; Hamilton, Andrew J
Small, remote communities often have limited access to energy and water. Direct potable reuse of treated wastewater has recently gained attention as a potential solution for water-stressed regions, but requires further evaluation specific to small communities. The required pathogen reduction needed for safe implementation of direct potable reuse of treated sewage is an important consideration but these are typically quantified for larger communities and cities. A quantitative microbial risk assessment (QMRA) was conducted, using norovirus, giardia and Campylobacter as reference pathogens, to determine the level of treatment required to meet the tolerable annual disease burden of 10(-6) DALYs per person per year, using Davis Station in Antarctica as an example of a small remote community. Two scenarios were compared: published municipal sewage pathogen loads and estimated pathogen loads during a gastroenteritis outbreak. For the municipal sewage scenario, estimated required log10 reductions were 6.9, 8.0 and 7.4 for norovirus, giardia and Campylobacter respectively, while for the outbreak scenario the values were 12.1, 10.4 and 12.3 (95th percentiles). Pathogen concentrations are higher under outbreak conditions as a function of the relatively greater degree of contact between community members in a small population, compared with interactions in a large city, resulting in a higher proportion of the population being at risk of infection and illness. While the estimates of outbreak conditions may overestimate sewage concentration to some degree, the results suggest that additional treatment barriers would be required to achieve regulatory compliance for safe drinking water in small communities. Copyright © 2013 Elsevier B.V. All rights reserved.
Yildirim, Benay; Sengüven, Burcu; Demir, Cem
Objectives: The aim of the present study was to assess the prevalence of Herpes Simplex virus, Epstein Barr virus and Human Papilloma virus -16 in oral lichen planus cases and to evaluate whether any clinical variant, histopathological or demographic feature correlates with these viruses. Study Design: The study was conducted on 65 cases. Viruses were detected immunohistochemically. We evaluated the histopathological and demographic features and statistically analysed correlation of these...
SEIFI, Sharareh; ASVADI KERMANI, Iraj; DOLATKHAH, Roya; ASVADI KERMANI, Atabak; SAKHINIA, Ebrahim; ASGARZADEH, Mohammad; DASTGIRI, Saeed; EBRAHIMI, Ayoub; ASGHARI HAGGI, Arezou; NADRI, Mahsa; ASVADI KERMANI, Touraj
Background: Human papilloma virus causes benign and malignant abnormalities in different part of the body. The link between high risk types of HPV and some anogenital and aerodigestive tract cancer is well established. Oral HPV infection plays a role in developing oropharyngeal squamous cell carcinoma. We studied the prevalence of oral HPV in healthy individuals and its relative risk factors. Methods: Saliva samples of 114 healthy subjects were collected for HPV DNA analysis. Volunteers compl...
Dolores L. Guzmán-Herrador
Full Text Available We explore the potential of bacterial secretion systems as tools for genomic modification of human cells. We previously showed that foreign DNA can be introduced into human cells through the Type IV A secretion system of the human pathogen Bartonella henselae. Moreover, the DNA is delivered covalently attached to the conjugative relaxase TrwC, which promotes its integration into the recipient genome. In this work, we report that this tool can be adapted to other target cells by using different relaxases and secretion systems. The promiscuous relaxase MobA from plasmid RSF1010 can be used to deliver DNA into human cells with higher efficiency than TrwC. MobA also promotes DNA integration, albeit at lower rates than TrwC. Notably, we report that DNA transfer to human cells can also take place through the Type IV secretion system of two intracellular human pathogens, Legionella pneumophila and Coxiella burnetii, which code for a distantly related Dot/Icm Type IV B secretion system. This suggests that DNA transfer could be an intrinsic ability of this family of secretion systems, expanding the range of target human cells. Further analysis of the DNA transfer process showed that recruitment of MobA by Dot/Icm was dependent on the IcmSW chaperone, which may explain the higher DNA transfer rates obtained. Finally, we observed that the presence of MobA negatively affected the intracellular replication of C. burnetii, suggesting an interference with Dot/Icm translocation of virulence factors.
Venter, Marietjie; Treurnicht, Florette K; Buys, Amelia; Tempia, Stefano; Samudzi, Rudo; McAnerney, Johanna; Jacobs, Charlene A; Thomas, Juno; Blumberg, Lucille
Risk factors for human infection with highly pathogenic (HP) and low-pathogenic (LP) avian influenza (AI) H5N2 and H7N1 were investigated during outbreaks in ostriches in the Western Cape province, South Africa. Serum surveys were conducted for veterinarians, farmworkers, and laboratory and abattoir workers involved in 2 AI outbreaks in the Western Cape province: (1) controlling and culling of 42000 ostriches during (HPAI)H5N2 outbreaks in ostriches (2011) (n = 207); (2) movement control during (LPAI)H7N1 outbreaks in 2012 (n = 66). A third serosurvey was conducted on state veterinarians from across the country in 2012 tasked with disease control in general (n = 37). Antibodies to H5 and H7 were measured by means of hemagglutination inhibition and microneutralization assays, with microneutralization assay titers >40 considered positive. Two of 207 (1%) participants were seropositive for H5 and 4 of 207 (2%) for H7 in 2011, compared with 1 of 66 (1.5%) and 8 of 66 (13%) in 2012. Although individuals in all professions tested seropositive, abattoir workers (10 of 97; 10.3%) were significantly more at risk of influenza A(H7N1) infection (P = .001) than those in other professions (2 of 171;1.2%). Among state veterinarians, 4 of 37(11%) were seropositive for H7 and 1 of 37 (2.7%) for H5. Investigations of (LP)H7N1-associated fatalities in wild birds and quarantined exotic birds in Gauteng, AI outbreaks in poultry in KwaZulu-Natal, and ostriches in Western Cape province provide possible exposure events. (LPAI)H7N1 strains pose a greater infection-risk than (HPAI)H5N2 strains to persons involved in control of outbreaks in infected birds, with ostrich abattoir workers at highest risk. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: email@example.com.
Full Text Available This research was conducted as a series of cross-sectional epidemiological studies. It started in the 2003 and ended in 2008, having as sample sites the Sontea-Fortuna, Gorgova-Uzlina, Dunavat-Dranov and Razim-Sinoie lakes. The aim of the research was to assess the distribution and the pathogenicity of the Lernaea copepod among the inhabiting finfish populations, in various seasons of the time period. Lernaea spp was found in ctenopharyngodon idella, cyprinus carpio, liza aurata and liza haematocheila, only in two out of the four sampled complex of lakes, Razim-Sinoie and Dunavat-Dranov. The highest prevalence of the parasite was recorded in the autumns and at the beginning of the springs. The frequency of the parasitism was highest in the C. idella captured in the Dunavat-Dranov complex lakes (86.29%. The lesions caused by the copepod were mainly localized on the eye balls, the tegmentum and on the fins, where hemorrhagic and proliferative processes, as well as an overall increase in tegmentum mucus secretion, were noticed.
Full Text Available BACKGROUND: Infection with high-risk human papillomavirus (HPVtypes has been recognized as a causal factor for the development of cervical cancer and a number of other malignancies. Today, vaccines against HPV, highly effective in the prevention of persistent infection and precancerous lesions, are available for the routine clinical practice. OBJECTIVES: The data on the prevalence and type-specific HPV distribution in the population of each country are crucial for the surveillance of HPV type-specific prevalence at the onset of vaccination against HPV. METHODS: Women attending a preventive gynecological examination who had no history of abnormal cytological finding and/or surgery for cervical lesions were enrolled. All samples were tested for the presence of HPV by High-Risk Hybrid Capture 2 (HR HC2 and by a modified PCR-reverse line blot assay with broad spectrum primers (BS-RLB. RESULTS: Cervical smears of 1393 women were analyzed. In 6.5% of women, atypical cytological findings were detected. Altogether, 28.3% (394/1393 of women were positive for any HPV type by BS-RLB, 18.2% (254/1393 by HR HC2, and 22.3% (310/1393 by BS-RLB for HR HPV types. In women with atypical findings the prevalence for HR and any HPV types were significantly higher than in women with normal cytological findings. Overall, 36 different HPV types were detected, with HPV 16 being the most prevalent (4.8%. HPV positivity decreased with age; the highest prevalence was 31.5% in the age group 21-25 years. CONCLUSIONS: Our study subjects represent the real screening population. HPV prevalence in this population in the Czech Republic is higher than in other countries of Eastern Europe. Also the spectrum of the most prevalent HPV types differs from those reported by others but HPV 16 is, concordantly, the most prevalent type. Country-specific HPV type-specific prevalences provide baseline information which will enable to measure the impact of HPV vaccination in the future.
Citterio, Linda; Franzyk, Henrik; Palarasah, Yaseelan
was affected by conditions mimicking in vivo settings. Their activity was enhanced to an unexpected degree in the presence of human blood plasma for thirteen pathogenic Gram-positive and Gram-negative bacteria. MIC values typically decreased 2- to 16-fold in the presence of a human plasma concentration...... that alone did not damage the cell membrane. Hence, MIC and MBC data collected in these settings appear to represent a more appropriate basis for in vivo experiments preceding clinical trials. In fact, concentrations of peptidomimetics and peptide antibiotics (e.g. polymyxin B) required for in vivo...
Falana, A. A. [National Agency for Food and Drug Administration and Control (NAFDAC) (Nigeria)
It may be concluded from this project that L. monocytogenes and V. cholerae are part of the normal flora of the tropical marine and fishing boat environment, and can be controlled through the implementation of safety assurance schemes such as Good Hygiene Practices (GHP) and Hazard Analysis Critical Control Point (HACCP) systems. It is noteworthy that pathogens were detected in seafood at the inception of the project but after the workshop training for the exporters on safe handling practices, these pathogens have been eliminated in packaged raw seafood products. This improvement was also reflected in the low levels of S. aureus and V. parahaemolyticus obtained in the samples that were analysed. It is expected that with maintenance of, and strict adherence to the GHP and HACCP systems, Nigerian seafood products would be readily acceptable in the EU and the world market. (author)
Full Text Available The ubiquitous fungal pathogen Aspergillus fumigatus is a mediator of allergic sensitization and invasive disease in susceptible individuals. The significant genetic and phenotypic variability between and among clinical and environmental isolates are important considerations in host-pathogen studies of A. fumigatus-mediated disease. We observed decreased radial growth, rate of germination, and ability to establish colony growth in a single environmental isolate of A. fumigatus, Af5517, when compared to other clinical and environmental isolates. Af5517 also exhibited increased hyphal diameter and cell wall β-glucan and chitin content, with chitin most significantly increased. Morbidity, mortality, lung fungal burden, and tissue pathology were decreased in neutropenic Af5517-infected mice when compared to the clinical isolate Af293. Our results support previous findings that suggest a correlation between in vitro growth rates and in vivo virulence, and we propose that changes in cell wall composition may contribute to this phenotype.
Sattar, S. A.; Springthorpe, V. S.; Karim, Y.; Loro, P.
The chemical disinfection of virus-contaminated non-porous inanimate surfaces was investigated using coxsackievirus B3, adenovirus type 5, parainfluenza virus type 3 and coronavirus 229E as representatives of important nosocomial viral pathogens. A 10 microliter amount of the test virus, suspended in either faeces or mucin, was placed onto each stainless steel disk (about 1 cm in diameter) and the inoculum allowed to dry for 1 h under ambient conditions. Sixteen disinfectant formulations were...
Eisenman, H.C.; Nosanchuk, J.D.; Webber, J. Beau W.; Emerson, T.A.; Casadevall, A.
Melanin is a virulence factor for many pathogenic fungal species,including Cryptococcus neoformans. Melanin is deposited in the cell wall, and melanin isolated from this fungus retains the shape of the cells, resulting in hollow spheres called ``ghosts''. In this study, atomic force, scanning electron, and transmission electron microscopy revealed that melanin ghosts are covered with roughly spherical granular particles approximately 40-130 nm in diameter, and that the melanin is arranged in ...
Babič, Monika Novak; Zalar, Polona; Ženko, Bernard; Schroers, Hans-Josef; Džeroski, Sašo; Gunde-Cimerman, Nina
Energy constraints have altered consumer practice regarding the use of household washing machines. Washing machines were developed that use lower washing temperatures, smaller amounts of water and biodegradable detergents. These conditions may favour the enrichment of opportunistic human pathogenic fungi. We focused on the isolation of fungi from two user-accessible parts of washing machines that often contain microbial biofilms: drawers for detergents and rubber door seals. Out of 70 residential washing machines sampled in Slovenia, 79% were positive for fungi. In total, 72 strains belonging to 12 genera and 26 species were isolated. Among these, members of the Fusarium oxysporum and Fusarium solani species complexes, Candida parapsilosis and Exophiala phaeomuriformis represented 44% of fungi detected. These species are known as opportunistic human pathogens and can cause skin, nail or eye infections also in healthy humans. A machine learning analysis revealed that presence of detergents and softeners followed by washing temperature, represent most critical factors for fungal colonization. Three washing machines with persisting malodour that resulted in bad smelling laundry were analysed for the presence of fungi and bacteria. In these cases, fungi were isolated in low numbers (7.5 %), while bacteria Micrococcus luteus, Pseudomonas aeruginosa, and Sphingomonas species prevailed. Copyright © 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.
Lou, Li-Xia; Chen, Yi; Yu, Chao-Hui; Li, You-Ming; Ye, Juan
HIV/AIDS is a worldwide threat to human health with mortality, prevalence, and incidence rates varying widely. We evaluated the association between the global HIV/AIDS epidemic and national socioeconomic development. We obtained global age-standardized HIV/AIDS mortality, prevalence, and incidence rates from World Health Statistics Report of the World Health Organization. The human development indexes (HDIs) of 141 countries were obtained from a Human Development Report. Countries were divided into 4 groups according to the HDI distribution. We explored the association between HIV/AIDS epidemic and HDI information using Spearman correlation analysis, regression analysis, and the Kruskal-Wallis test. HIV/AIDS mortality, prevalence, and incidence rates were inversely correlated with national HDI (r = -0.675, -0.519, and -0.398, respectively; P birth, mean years of schooling, expected years of schooling, and gross national income per capita). Low HDI countries had higher HIV/AIDS mortality, prevalence, and incidence rates than that of medium, high, and very high HDI countries. Quantile regression results indicated that HDI had a greater negative effect on the HIV/AIDS epidemic in countries with more severe HIV/AIDS epidemic. Less-developed countries are likely to have more severe HIV/AIDS epidemic. There is a need to pay more attention to HIV/AIDS control in less-developed countries, where lower socioeconomic status might have accelerated the HIV/AIDS epidemic more rapidly. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
Andrea J Dowling
Full Text Available Burkholderia pseudomallei is an important human pathogen whose infection biology is still poorly understood. The bacterium is endemic to tropical regions, including South East Asia and Northern Australia, where it causes melioidosis, a serious disease associated with both high mortality and antibiotic resistance. B. pseudomallei is a Gram-negative facultative intracellular pathogen that is able to replicate in macrophages. However despite the critical nature of its interaction with macrophages, few anti-macrophage factors have been characterized to date. Here we perform a genome-wide gain of function screen of B. pseudomallei strain K96243 to identify loci encoding factors with anti-macrophage activity. We identify a total of 113 such loci scattered across both chromosomes, with positive gene clusters encoding transporters and secretion systems, enzymes/toxins, secondary metabolite, biofilm, adhesion and signal response related factors. Further phenotypic analysis of four of these regions shows that the encoded factors cause striking cellular phenotypes relevant to infection biology, including apoptosis, formation of actin 'tails' and multi-nucleation within treated macrophages. The detailed analysis of the remaining host of loci will facilitate genetic dissection of the interaction of this important pathogen with host macrophages and thus further elucidate this critical part of its infection cycle.
Maier Christina J
Full Text Available Abstract Background The Gram-negative bacterium Chlamydia pneumoniae (Cpn is the leading intracellular human pathogen responsible for respiratory infections such as pneumonia and bronchitis. Basic and applied research in pathogen biology, especially the elaboration of new mechanism-based anti-pathogen strategies, target discovery and drug development, rely heavily on the availability of the entire set of pathogen open reading frames, the ORFeome. The ORFeome of Cpn will enable genome- and proteome-wide systematic analysis of Cpn, which will improve our understanding of the molecular networks and mechanisms underlying and governing its pathogenesis. Results Here we report the construction of a comprehensive gene collection covering 98.5% of the 1052 predicted and verified ORFs of Cpn (Chlamydia pneumoniae strain CWL029 in Gateway® ‘entry’ vectors. Based on genomic DNA isolated from the vascular chlamydial strain CV-6, we constructed an ORFeome library that contains 869 unique Gateway® entry clones (83% coverage and an additional 168 PCR-verified ‘pooled’ entry clones, reaching an overall coverage of ~98.5% of the predicted CWL029 ORFs. The high quality of the ORFeome library was verified by PCR-gel electrophoresis and DNA sequencing, and its functionality was demonstrated by expressing panels of recombinant proteins in Escherichia coli and by genome-wide protein interaction analysis for a test set of three Cpn virulence factors in a yeast 2-hybrid system. The ORFeome is available in different configurations of resource stocks, PCR-products, purified plasmid DNA, and living cultures of E. coli harboring the desired entry clone or pooled entry clones. All resources are available in 96-well microtiterplates. Conclusion This first ORFeome library for Cpn provides an essential new tool for this important pathogen. The high coverage of entry clones will enable a systems biology approach for Cpn or host–pathogen analysis. The high yield of
Jha, Babita; Rao, Mugdha; Prasad, K.; Jha, Anal K.
The present work encompasses the fabrication of biocompatible silver nanoparticles from the leaves of the medicinal plant Piper betle using green chemistry approach. The synthesized nanoparticles were characterized by different standard techniques like: UV-visible spectroscopy, X-ray diffraction, scanning electron microscopy and Fourier transformed infrared spectroscopy. The antimicrobial efficacy of the silver nanoparticles was assessed against human and plant pathogens namely Ralstonia solanacearum, Burkholderia gladioli, Escherichia coli and Sacchromyces cerevisiae by agar well diffusion method. The obtained results clearly indicate its possible use as an alternative to antibiotics and pesticides in near future.
Nielsen, Jesper Sejrup; Lei Kristensen, Lisbeth; Hanghøj Chrisitansen, Mie
between sRNA and target mRNA rely on the RNA chaperone Hfq. Hfq is a ubiquitous protein found in almost all genres of bacterial life. However, so far its role as an RNA chaperone has only been described in Gram-negative species such as Escherichia coli and Salmonella (Vogel, J. 2009). We previously...... identified several Hfq-binding sRNAs in the Gram-positive human pathogen L. monocytogenes (Christiansen et al 2006). Through bioinformatics, we have identified a number of candidate targets for one of these sRNAs (LhrA). Here, we present the characterization of one of these targets. Our results suggest...
Maier, R J
Molecular hydrogen is produced as a fermentation by-product in the large intestine of animals and its production can be correlated with the digestibility of the carbohydrates consumed. Pathogenic Helicobacter species (Helicobacter pylori and H. hepaticus) have the ability to use H(2) through a respiratory hydrogenase, and it was demonstrated that the gas is present in the tissues colonized by these pathogens (the stomach and the liver respectively of live animals). Mutant strains of H. pylori unable to use H(2) are deficient in colonizing mice compared with the parent strain. On the basis of available annotated gene sequence information, the enteric pathogen Salmonella, like other enteric bacteria, contains three putative membrane-associated H(2)-using hydrogenase enzymes. From the analysis of gene-targeted mutants it is concluded that each of the three membrane-bound hydrogenases of Salmonella enterica serovar Typhimurium are coupled with an H(2)-oxidizing respiratory pathway. From microelectrode probe measurements on live mice, H(2) could be detected at approx. 50 muM levels within the tissues (liver and spleen), which are colonized by Salmonella. The half-saturation affinity of whole cells of these pathogens for H(2) is much less than this, so it is expected that the (H(2)-utilizing) hydrogenase enzymes be saturated with the reducing substrate in vivo. All three enteric NiFe hydrogenase enzymes contribute to virulence of the bacterium in a typhoid fever-mouse model, and the combined removal of all three hydrogenases resulted in a strain that is avirulent and (in contrast with the parent strain) one that is not able to pass the intestinal tract to invade liver or spleen tissue. It is proposed that H(2) utilization and specifically its oxidation, coupled with a respiratory pathway, is required for energy production to permit growth and maintain efficient virulence of a number of pathogenic bacteria during infection of animals. These would be expected to include
Hernandez Gonzalez, Gertrudis de los Angeles; Alvarez Sanchez, Marilet; Jordan Gonzalez, Jose
To determine the prevalence of incidental findings in healthy subjects of the Cuban Human Brain Mapping Project sample, it was performed a retrospective descriptive study of the magnetic resonance imaging (MRI) obtained from 394 healthy subjects that make up the sample of the project, between 2006-2007, with an age range of 18 to 68 years (mean 33,12), of which 269 (68,27 %) are male and 125 (31,73 %) are women. It was shown that 40,36 % had one or more anomaly in the magnetic resonance imaging (MRI). In total, the number of incidental findings was 188, 23,6 % of which were brain findings and 24,11 % were non-brain findings, among the latter, were the sinusopathy with 20,81 % and maxillary polyps with 3,30 %. The most prevalent brain findings were: intrasellar arachnoidocele, 11,93 %, followed by the prominence of the pituitary gland, 5,84 %, ventricular asymmetry, 1,77 % and bone defects, 1,02 %. Other brain abnormalities found with very low prevalence had no pathological significance, except for two cases with brain tumor, which were immediately sent to a specialist. Incidental findings in MRI are common in the general population (40,36 %), being the sinusopathy, and intrasellar arachnoidocele the most common findings. Asymptomatic individuals who have any type of structural abnormality provide invaluable information on the prevalence of these abnormalities in a presumably healthy population, which may be used as references for epidemiological studies
Kaur, Parminder; Aggarwal, Aruna; Nagpal, Madhu; Oberoi, Loveena; Sharma, Swati
Cervical cancer is the commonest cancer among Indian women. High-risk human papilloma virus (HPV) detection holds the potential to be used as a tool to identify women, at risk of subsequent development of cervical cancer. There is a pressing need to identify prevalence of asymptomatic cervical HPV infection in local population. In our study, we explored the prevalence of HPV genotypes and their distribution in women with cervical lesions. Scrape specimens were obtained from 100 women (study group) with cervical abnormalities. HPV was detected with amplicor HPV tests, and the individual genotypes in these specimens were identified by Hybribio Genoarray test kit. Fifty specimens were also collected from females with healthy cervix (control group). The present study also aimed to determine the status of HPV prevalence and its association with different sociodemographic factors. Out of the total number of 100 samples, 10 (10 %) women tested positive for HPV DNA. Among them, HPV 18 was observed in 6, HPV 16 in 2, HPV 52 and HPV 39 in one each. Fifty specimens collected from patients with healthy cervix were not infected with any of the HPV genotype. Our study generates data of HPV prevalence in patients with cervical lesions visiting tertiary care institute. The data generated will be useful for laying guidelines for mass screening of HPV detection, treatment, and prophylaxis.
Wöllert, Torsten; Langford, George M
Long-term live cell imaging was used in this study to determine the responses of human epithelial cells to pathogenic biofilms formed by Candida albicans. Epithelial cells of the skin represent the front line of defense against invasive pathogens such as C. albicans but under certain circumstances, especially when the host's immune system is compromised, the skin barrier is breached. The mechanisms by which the fungal pathogen penetrates the skin and invade the deeper layers are not fully understood. In this study we used keratinocytes grown in culture as an in vitro model system to determine changes in host cell migration and the actin cytoskeleton in response to virulence factors produced by biofilms of pathogenic C. albicans. It is clear that changes in epithelial cell migration are part of the response to virulence factors secreted by biofilms of C. albicans and the actin cytoskeleton is the downstream effector that mediates cell migration. Our goal is to understand the mechanism by which virulence factors hijack the signaling pathways of the actin cytoskeleton to alter cell migration and thereby invade host tissues. To understand the dynamic changes of the actin cytoskeleton during infection, we used long-term live cell imaging to obtain spatial and temporal information of actin filament dynamics and to identify signal transduction pathways that regulate the actin cytoskeleton and its associated proteins. Long-term live cell imaging was achieved using a high resolution, multi-mode epifluorescence microscope equipped with specialized light sources, high-speed cameras with high sensitivity detectors, and specific biocompatible fluorescent markers. In addition to the multi-mode epifluorescence microscope, a spinning disk confocal long-term live cell imaging system (Olympus CV1000) equipped with a stage incubator to create a stable in vitro environment for long-term real-time and time-lapse microscopy was used. Detailed descriptions of these two long-term live
Shanaka, K A S N; Wilathgamuwa, S; Gunawardene, Y I N S; Dassanayake, R S
Human papilloma virus (HPV) causes cervical cancer in women and approximately 700 deaths have been reported annually in Sri Lanka due to this cancer. Despite, attempts have not been made to investigate the prevalence of HPV amongst Sri Lankan women with normal cytology. In this study, a polymerase chain reaction based assay was set up to detect HPV in both normal and abnormal cytology and the positive samples were then tested for the genotypes, HPV 16 and HPV 18 as they have been identified as the high-risk types associating with cervical cancer. Eighty-four (number = 84) clinical samples (age range 27-69) analyzed in this study indicated that the prevalence of HPV, regardless of cytological abnormalities was 15.5%, (n = 13, 95% class interval ± 7.7) while it was 100% (n = 3) for those with abnormal cytology. Association of HPV 16 and HPV 18 among the abnormal cytology was 0 and 50% (n = 1), respectively and further, the prevalence of HPV 16 and HPV 18 in women was found to be 3.6% (n = 3, 95% CI ± 4.0) and 2.4% (n = 2, 95% CI ± 3.3), respectively. Moreover, age wise prevalence analysis revealed women of the age of 35-years or more to have higher HPV prevalence. The prevalence of HPV among normal cytology is 12.3% (n = 10, 95% CI ± 7.2) which is similar to the rates in other regions of Asia (China 15.4%; India 10.43%). Finally, higher prevalence of HPV in women of the age of 35-years or more in Sri Lanka, especially with malignant types call for such age group to be screened for proper clinical intervention to be made in reducing the incident of cervical cancers. This is the first report of prevalence of HPV among women with normal cytology in Sri Lanka.
Segel-Karpas, Dikla; Bamberger, Peter A; Bacharach, Samuel B
The aging of the workforce in the developed world has prompted organizations to implement human resource (HR) policies and practices encouraging older workers to defer retirement. However, little is known about the prevalence of such practices, and the organizational factors associated with their adoption. In this study, we used data collected from 2008 to 2009 from a national probability sample of retirement eligible workers in the United States (N = 407) to assess the prevalence of aging-friendly human resource practices (AFHRP), and their organizational predictors. Results indicate that employee wellness programs, unpaid leave, and reassignment based on physical needs are among the most prevalent AFHRP. However, in the vast majority of enterprises, AFHRP are limited. Results also indicate that projected organizational growth and a focus on internal labor market practices are positively associated with the adoption of AFHRP. Organizational size and the degree of unionization, while positively associated with aging-friendly benefits, were inversely associated with flexibility practices. © The Author(s) 2015.
Gołyńska, Magdalena; Polkowska, Izabela; Bartoszcze-Tomaszewska, Małgorzata; Sobczyńska-Rak, Aleksandra; Matuszewski, Łukasz
Dogs commonly serve as a model for various human conditions, including periodontal diseases. The aim of this study was to identify the anaerobic bacteria that colonize the subgingival areas in dogs and humans by using rapid real-time polymerase chain reaction (RT-PCR)-based tests and to compare the results obtained in each species. Bacterial microflora evaluations, both quantitative and qualitative, were performed by applying ready-made tests on twelve dogs and twelve humans. Five samples were collected from each subject's deepest gingival pockets and joined to form a collective sample. The results of the study revealed interspecies similarities in the prevalences of Porphyromonas ( P .) gingivalis, Treponema denticola, Tannerella forsythia , and Fusobacterium nucleatum . Red complex bacteria comprised the largest portion of the studied bacterial complexes in all study groups, with P. gingivalis being the most commonly isolated bacterium. The results show similarities in the prevalence of bacterial microflora in dogs and humans. Microbiological analysis of gingival pockets by using rapid real-time PCR-based tests in clinical practice, both veterinary and human, can facilitate the choice of appropriate pharmacological treatment and can provide a basis for subsequent verification of the treatment's effectiveness.
Full Text Available The nares represent an important bacterial reservoir for endogenous infections. This study aimed to assess the prevalence of nasal colonization by different important pathogens, the associated antimicrobial susceptibility and risk factors. We performed a prospective cohort study among 1878 nonhospitalized volunteers recruited from the general population in Germany. Participants provided nasal swabs at three time points (each separated by 4–6 months. Staphylococcus aureus, Enterobacteriaceae and important nonfermenters were cultured and subjected to susceptibility testing. Factors potentially influencing bacterial colonization patterns were assessed. The overall prevalence of S. aureus, Enterobacteriaceae and nonfermenters was 41.0, 33.4 and 3.7%, respectively. Thirteen participants (0.7% were colonized with methicillin-resistant S. aureus. Enterobacteriaceae were mostly (>99% susceptible against ciprofloxacin and carbapenems (100%. Extended-spectrum β-lactamase–producing isolates were not detected among Klebsiella oxytoca, Klebsiella pneumoniae and Escherichia coli. Several lifestyle- and health-related factors (e.g. household size, travel, livestock density of the residential area or occupational livestock contact, atopic dermatitis, antidepressant or anti-infective drugs were associated with colonization by different microorganisms. This study unexpectedly demonstrated high nasal colonization rates with Enterobacteriaceae in the German general population, but rates of antibiotic resistance were low. Methicillin-resistant S. aureus carriage was rare but highly associated with occupational livestock contact.
Mogensen, Klaus Bo; Machado, Ana Manuel; Dufva, Martin
-situ hybridization assay is used (PNA-FISH) for diagnosis of hospital acquired bacteria, such as staphylococcus aureus, enterococcus faecalis, E. coli, candida albicans etc. The test covers 90-95 % of the species by prevalence. It is based on a microscope slide format with inspection of the fluorescing bacteria...
Roager, Henrik Munch; Laursen, Martin Frederik; Lildballe, Dorte L.
commensal and pathogenic bacteria to which infants are likely to be exposed. Well-diffusion assays addressing antibacterial effects were performed with human milk, haptocorrin-free human milk, porcine holo-haptocorrin (saturated with B-12) and human apo-haptocorrin (unsaturated). Human milk inhibited...... properties of this protein may exert a general defense against pathogens and/or affect the composition of the developing microbiota in the gastrointestinal tracts of breastfed infants. Findings: The present work was the first systematic study of the effect of haptocorrin on bacterial growth, and included 34...... the growth of S. thermophilus and the pathogenic strains L. monocytogenes LO28, L. monocytogenes 4446 and L. monocytogenes 7291, but the inhibition could not be ascribed to haptocorrin. Human apo-haptocorrin inhibited the growth of only a single bacterial strain (Bifidobacterium breve), while porcine holo...
Full Text Available Abstract Background Comparative genomics has greatly improved our understanding of the evolution of pathogenic mycobacteria such as Mycobacterium tuberculosis. Here we have used data from a genome microarray analysis to explore insertion-deletion (InDel polymorphism among a diverse strain collection of Mycobacterium ulcerans, the causative agent of the devastating skin disease, Buruli ulcer. Detailed analysis of large sequence polymorphisms in twelve regions of difference (RDs, comprising irreversible genetic markers, enabled us to refine the phylogenetic succession within M. ulcerans, to define features of a hypothetical M. ulcerans most recent common ancestor and to confirm its origin from Mycobacterium marinum. Results M. ulcerans has evolved into five InDel haplotypes that separate into two distinct lineages: (i the "classical" lineage including the most pathogenic genotypes – those that come from Africa, Australia and South East Asia; and (ii an "ancestral" M. ulcerans lineage comprising strains from Asia (China/Japan, South America and Mexico. The ancestral lineage is genetically closer to the progenitor M. marinum in both RD composition and DNA sequence identity, whereas the classical lineage has undergone major genomic rearrangements. Conclusion Results of the InDel analysis are in complete accord with recent multi-locus sequence analysis and indicate that M. ulcerans has passed through at least two major evolutionary bottlenecks since divergence from M. marinum. The classical lineage shows more pronounced reductive evolution than the ancestral lineage, suggesting that there may be differences in the ecology between the two lineages. These findings improve the understanding of the adaptive evolution and virulence of M. ulcerans and pathogenic mycobacteria in general and will facilitate the development of new tools for improved diagnostics and molecular epidemiology.
Beaussart, Audrey; Péchoux, Christine; Trieu-Cuot, Patrick; Hols, Pascal; Mistou, Michel-Yves; Dufrêne, Yves F.
The surface of many bacterial pathogens is covered with polysaccharides that play important roles in mediating pathogen-host interactions. In Streptococcus agalactiae, the capsular polysaccharide (CPS) is recognized as a major virulence factor while the group B carbohydrate (GBC) is crucial for peptidoglycan biosynthesis and cell division. Despite the important roles of CPS and GBC, there is little information available on the molecular organization of these glycopolymers on the cell surface. Here, we use atomic force microscopy (AFM) and transmission electron microscopy (TEM) to analyze the nanoscale distribution of CPS and GBC in wild-type (WT) and mutant strains of S. agalactiae. TEM analyses reveal that in WT bacteria, peptidoglycan is covered with a very thin (few nm) layer of GBC (the ``pellicle'') overlaid by a 15-45 nm thick layer of CPS (the ``capsule''). AFM-based single-molecule mapping with specific antibody probes shows that CPS is exposed on WT cells, while it is hardly detected on mutant cells impaired in CPS production (ΔcpsE mutant). By contrast, both TEM and AFM show that CPS is over-expressed in mutant cells altered in GBC expression (ΔgbcO mutant), indicating that the production of the two surface glycopolymers is coordinated in WT cells. In addition, AFM topographic imaging and molecular mapping with specific lectin probes demonstrate that removal of CPS (ΔcpsE), but not of GBC (ΔgbcO), leads to the exposure of peptidoglycan, organized into 25 nm wide bands running parallel to the septum. These results indicate that CPS forms a homogeneous barrier protecting the underlying peptidoglycan from environmental exposure, while the presence of GBC does not prevent peptidoglycan detection. This work shows that single-molecule AFM, combined with high-resolution TEM, represents a powerful platform for analysing the molecular arrangement of the cell wall polymers of bacterial pathogens.
Holl, Katsiaryna; Nowakowski, Andrzej M; Powell, Ned
Cervical glandular neoplasias (CGN) present a challenge for cervical cancer prevention due to their complex histopathology and difficulties in detecting preinvasive stages with current screening practices. Reports of human papillomavirus (HPV) prevalence and type-distribution in CGN vary, providing...... uncertain evidence to support prophylactic vaccination and HPV screening. This study [108288/108290] assessed HPV prevalence and type-distribution in women diagnosed with cervical adenocarcinoma in situ (AIS, N = 49), adenosquamous carcinoma (ASC, N = 104), and various adenocarcinoma subtypes (ADC, N = 461...... of CGN are HPV16/18/45-positive, the incorporation of prophylactic vaccination and HPV testing in cervical cancer screening are important prevention strategies. Our results suggest that special attention should be given to certain rarer ADC subtypes as most appear to be unrelated to HPV....
BACKGROUND: Human intestinal epithelial cells (IECs) secrete the chemokine CCL20 in response to infection by various enteropathogenic bacteria or exposure to bacterial flagellin. CCL20 recruits immature dendritic cells and lymphocytes to target sites. Here we investigated IEC responses to various pathogenic and commensal bacteria as well as the modulatory effects of commensal bacteria on pathogen-induced CCL20 secretion. HT-29 human IECs were incubated with commensal bacteria (Bifidobacterium infantis or Lactobacillus salivarius), or with Salmonella typhimurium, its flagellin, Clostridium difficile, Mycobacterium paratuberculosis, or Mycobacterium smegmatis for varying times. In some studies, HT-29 cells were pre-treated with a commensal strain for 2 hr prior to infection or flagellin stimulation. CCL20 and interleukin (IL)-8 secretion and nuclear factor (NF)-kappaB activation were measured using enzyme-linked immunosorbent assays. RESULTS: Compared to untreated cells, S. typhimurium, C. difficile, M. paratuberculosis, and flagellin activated NF-kappaB and stimulated significant secretion of CCL20 and IL-8 by HT-29 cells. Conversely, B. infantis, L. salivarius or M. smegmatis did not activate NF-kappaB or augment CCL20 or IL-8 production. Treatment with B. infantis, but not L. salivarius, dose-dependently inhibited the baseline secretion of CCL20. In cells pre-treated with B. infantis, C. difficile-, S. typhimurium-, and flagellin-induced CCL20 were significantly attenuated. B. infantis did not limit M. Paratuberculosis-induced CCL20 secretion. CONCLUSION: This study is the first to demonstrate that a commensal strain can attenuate CCL20 secretion in HT-29 IECs. Collectively, the data indicate that M. paratuberculosis may mediate mucosal damage and that B. infantis can exert immunomodulatory effects on IECs that mediate host responses to flagellin and flagellated enteric pathogens.
Full Text Available Abstract Background Helicobacter pylori (Hp, a human pathogen that is associated with gastritis, peptic ulcer, and gastric cancer, has been considered a microaerophile, but there is no general consensus about its specific O2 requirements. A clear understanding of Hp physiology is needed to elucidate the pathogenic mechanism(s of Hp infection. Results We cultured Hp under a range of O2 levels with or without 10% CO2 and evaluated growth profiles, morphology, intracellular pH, and energy metabolism. We found that, in the presence of 10% CO2, the normal atmospheric level of O2 inhibited Hp growth at low density but stimulated growth at a higher density. Field emission scanning electron microscopy and fluorescence microscopy of Hp cells cultured under 20% O2 tension revealed live spiral-shaped bacteria with outer membrane vesicles on a rugged cell surface, which became smooth during the stationary phase. Fermentation products including acetate, lactate, and succinate were detected in cell culture media grown under microaerobic conditions, but not under the aerobic condition. CO2 deprivation for less than 24 h did not markedly change cytoplasmic or periplasmic pH, suggesting that cellular pH homeostasis alone cannot account for the capnophilic nature of Hp. Further, CO2 deprivation significantly increased intracellular levels of ppGpp and ATP but significantly decreased cellular mRNA levels, suggesting induction of the stringent response. Conclusions We conclude, unlike previous reports, that H. pylori may be a capnophilic aerobe whose growth is promoted by atmospheric oxygen levels in the presence of 10% CO2. Our data also suggest that buffering of intracellular pH alone cannot account for the CO2 requirement of H. pylori and that CO2 deprivation initiates the stringent response in H. pylori. Our findings may provide new insight into the physiology of this fastidious human pathogen.
Julia M. Michelotti
Full Text Available The World Health Organization (WHO estimates that zoonotic diseases transmitted from animals to humans account for 75 percent of new and emerging infectious diseases. Globally, high-consequence pathogens that impact livestock and have the potential for human transmission create research paradoxes and operational challenges for the high-containment laboratories that conduct work with them. These specialized facilities are required for conducting all phases of research on high-consequence pathogens (basic, applied, and translational with an emphasis on both the generation of fundamental knowledge and product development. To achieve this research mission, a highly-trained workforce is required and flexible operational methods are needed. In addition, working with certain pathogens requires compliance with regulations such as the Centers for Disease Control (CDC and the U.S. Department of Agriculture (USDA Select Agent regulations, which adds to the operational burden. The vast experience from the existing studies at Plum Island Animal Disease Center, other U.S. laboratories, and those in Europe and Australia with biosafety level 4 (BSL-4 facilities designed for large animals, clearly demonstrates the valuable contribution this capability brings to the efforts to detect, prepare, prevent and respond to livestock and potential zoonotic threats. To raise awareness of these challenges, which include biosafety and biosecurity issues, we held a workshop at the 2018 American Society for Microbiology (ASM Biothreats conference to further discuss the topic with invited experts and audience participants. The workshop covered the subjects of research funding and metrics, economic sustainment of drug and vaccine development pipelines, workforce turnover, and the challenges of maintaining operational readiness of high containment laboratories.
Park, Eun-Ah; Kim, You-Tae; Cho, Jae-Hyun; Ryu, Sangryeol; Lee, Ju-Hoon
Klebsiella is a genus of well-known opportunistic human pathogens that are associated with diabetes mellitus and chronic pulmonary obstruction; however, this pathogen is often resistant to multiple drugs. To control this pathogen, two Klebsiella-infecting phages, K. oxytoca phage PKO111 and K. pneumoniae phage PKP126, were isolated from a sewage sample. Analysis of their host range revealed that they infect K. pneumoniae and K. oxytoca, suggesting host specificity for members of the genus Klebsiella. Stability tests confirmed that the phages are stable under various temperature (4 to 60 °C) and pH (3 to 11) conditions. A challenge assay showed that PKO111 and PKP126 inhibit growth of their host strains by 2 log and 4 log, respectively. Complete genome sequencing of the phages revealed that their genome sizes are quite different (168,758 bp for PKO111 and 50,934 bp for PKP126). Their genome annotation results showed that they have no human virulence-related genes, an important safety consideration. In addition, no lysogen-formation gene cluster was detected in either phage genome, suggesting that they are both virulent phages in their bacterial hosts. Based on these results, PKO111 and PKP126 may be good candidates for development of biocontrol agents against members of the genus Klebsiella for therapeutic purposes. A comparative analysis of tail-associated gene clusters of PKO111 and PKP126 revealed relatively low homology, suggesting that they might differ in the way they recognize and infect their specific hosts.
Vödisch, Martin; Albrecht, Daniela; Lessing, Franziska; Schmidt, André D; Winkler, Robert; Guthke, Reinhard; Brakhage, Axel A; Kniemeyer, Olaf
The filamentous fungus Aspergillus fumigatus has become the most important airborne fungal pathogen causing life-threatening infections in immunosuppressed patients. We established a 2-D reference map for A. fumigatus. Using MALDI-TOF-MS/MS, we identified 381 spots representing 334 proteins. Proteins involved in cellular metabolism, protein synthesis, transport processes and cell cycle were most abundant. Furthermore, we established a protocol for the isolation of mitochondria of A. fumigatus and developed a mitochondrial proteome reference map. 147 proteins represented by 234 spots were identified.
Yasinzai, M. I.; Kakarsulemankhel, J. K.
Objective: To study the prevalence of malarial infections in human population of district Panjgur in south-western Pakistan. Methods: The cross-sectional study identified malarial parasites in the blood slides of 6119 suspected malaria patients from July 2006 to June 2008 through passive and active case detection methods. SPSS 11 was used for statistical analysis. Results: Out of 6119 suspected cases of malaria, 2346 (38.3%) were found to be positive for malarial parasite on blood smear slides. Of these, 1868 (79.6%) cases were due to Plasmodium vivax infection, and 478 (20.3%) had P. falciparum. However, seasonal variation was also noted: P. vivax infection was the highest (n=131/144, 90.9%) in November and the lowest (n=83/176, 47.1%) in October. The prevalence was higher (n=1831, 78%) in males. Age-wise, the prevalence of the disease was 81.2% (n=334) and 80% (n=860) for age groups 1-10 years and 11-20 years. No case of P. malaria and P. ovale was detected in the study period. No association was found between types of infection and age groups. Conclusion: Human malaria infection was quite frequent in the study region, which is one of the hottest areas of Balochistan, Pakistan. In clinically-suspected cases of malaria, there was a high slide positivity rate. The high prevalence rate of P. vivax poses a significant health hazard but P. falciparum also may lead to serious complications, including cerebral malaria. (author)
Combes, Jean-Damien; Chen, Alyce A; Franceschi, Silvia
Oropharyngeal cancer (OPC) is more frequent in men than women mainly due to the heavier and longer duration of smoking in men. Human papillomavirus (HPV) has a role in the rising incidence of OPC in the United States and other high-income countries. To determine whether there is a difference in the proportion of HPV-attributable OPC between men and women, we systematically retrieved HPV prevalence data from 63 studies reporting separately on OPC by gender. The male/female (M/F) ratios of HPV prevalence in OPC across different countries and the corresponding M/F ratios of cumulative lung cancer risk (a proxy for smoking) were compared. The United States had the highest M/F ratios of HPV prevalence in OPC (1.5). The lowest M/F ratios (≤0.7) were found in Asia and some European countries (e.g., France). The countries in which the M/F ratio of HPV prevalence in OPC was ≥1.0 had the most similar lung cancer risks for men and women. When HPV prevalence data were applied to age-standardized OPC incidence rates in the United States, Australia, the United Kingdom, and France, the M/F ratio for the HPV-positive OPC incidence rates was rather stable (around 4) in all countries. In contrast, the M/F ratio for the HPV-negative OPC incidence rates reached 10.2 in France versus gender and country mainly as a consequence of the vast international variation in male smoking habits. Nevertheless, HPV-positive OPC may affect men more heavily than women in different populations for reasons that are unclear. ©2014 American Association for Cancer Research.
Guo, L W; Zhang, S K; Liu, S Z; Chen, Q; Zhang, M; Quan, P L; Lu, J B; Sun, X B
Globally, the prevalence of oesophageal cancer cases is particularly high in China. Since 1982, oncogenic human papillomavirus (HPV) has been hypothesized as a risk factor for oesophageal cancer, but no firm evidence of HPV infection in oesophageal cancer has been established to date. We aimed to conduct a meta-analysis to estimate the high-risk HPV-18 prevalence of oesophageal cancer in the Chinese population. Eligible studies published from 1 January 2005 to 12 July 2014 were retrieved via computer searches of English and Chinese literature databases (including Medline, EMBASE, Chinese National Knowledge Infrastructure and Wanfang Data Knowledge Service Platform). A random-effects model was used to calculate pooled prevalence and corresponding 95% confidence intervals (CIs). A total of 2556 oesophageal cancer cases from 19 studies were included in this meta-analysis. Overall, the pooled HPV-18 prevalence in oesophageal cancer cases was 4·1% (95% CI 2·7-5·5) in China, 6·1% (95% CI 2·9-9·3) in fresh or frozen biopsies and 4·0% (95% CI 2·3-5·8) in paraffin-embedded fixed biopsies, 8·2% (95% CI 4·6-11·7) by the E6/E7 region and 2·2% (95% CI 0·9-3·6) by the L1 region of the HPV gene. This meta-analysis indicated that China has a moderate HPV-18 prevalence of oesophageal cancer compared to cervical cancer, although there is variation between different variables. Further studies are needed to elucidate the role of HPV in oesophagus carcinogenesis with careful consideration of study design and laboratory detection method, providing more accurate assessment of HPV status in oesophageal cancer.
Osborne, Christina; Cryan, Paul M.; O'Shea, Thomas J.; Oko, Lauren M.; Ndaluka, Christina; Calisher, Charles H.; Berglund, Andrew D.; Klavetter, Mead L.; Holmes, Kathryn V.; Dominguez, Samuel R.; Montgomery, Joel Mark
Bats are reservoirs for many different coronaviruses (CoVs) as well as many other important zoonotic viruses. We sampled feces and/or anal swabs of 1,044 insectivorous bats of 2 families and 17 species from 21 different locations within Colorado from 2007 to 2009. We detected alphacoronavirus RNA in bats of 4 species: big brown bats (Eptesicus fuscus), 10% prevalence; long-legged bats (Myotis volans), 8% prevalence; little brown bats (Myotis lucifugus), 3% prevalence; and western long-eared bats (Myotis evotis), 2% prevalence. Overall, juvenile bats were twice as likely to be positive for CoV RNA as adult bats. At two of the rural sampling sites, CoV RNAs were detected in big brown and long-legged bats during the three sequential summers of this study. CoV RNA was detected in big brown bats in all five of the urban maternity roosts sampled throughout each of the periods tested. Individually tagged big brown bats that were positive for CoV RNA and later sampled again all became CoV RNA negative. Nucleotide sequences in the RdRp gene fell into 3 main clusters, all distinct from those of Old World bats. Similar nucleotide sequences were found in amplicons from gene 1b and the spike gene in both a big-brown and a long-legged bat, indicating that a CoV may be capable of infecting bats of different genera. These data suggest that ongoing evolution of CoVs in bats creates the possibility of a continued threat for emergence into hosts of other species. Alphacoronavirus RNA was detected at a high prevalence in big brown bats in roosts in close proximity to human habitations (10%) and known to have direct contact with people (19%), suggesting that significant potential opportunities exist for cross-species transmission of these viruses. Further CoV surveillance studies in bats throughout the Americas are warranted.
Rosen, Brian J; Walter, Leora; Gilman, Robert H; Cabrerra, Lilia; Gravitt, Patti E; Marks, Morgan A
The incidence of human papillomavirus (HPV) associated head and neck cancers (HNCs) have been increasing in Peru. However, the burden of oral HPV infection in Peru has not been assessed. The objective of this cross-sectional study was to estimate the prevalence and correlates of oral HPV infection in a population-based sample from males and females from Lima, Peru. Between January 2010 and June 2011, a population-based sample of 1099 individuals between the ages of 10 and 85 from a low-income neighbourhood in Lima, Peru was identified through random household sampling. Information on demographic, sexual behaviours, reproductive factors and oral hygiene were collected using interviewer-administered questionnaires. Oral rinse specimens were collected from each participant, and these specimens were genotyped using the Roche Linear Array assay. ORs were used to assess differences in the prevalence of any oral HPV and any high-risk oral HPV infection by demographic factors, sexual practices and oral hygiene among individuals 15+ years of age. The prevalence of any HPV and any high-risk HPV (HR-HPV) was 6.8% and 2.0%, respectively. The three most common types were HPV 55 (3.4%), HPV 6 (1.5%) and HPV 16 (1.1%). Male sex (aOR, 2.21; 95% CI 1.22 to 4.03) was associated with any HPV infection after adjustment. The prevalence of oral HPV in this study was similar to estimates observed in the USA. Higher prevalence of oral infections in males was consistent with a male predominance of HPV-associated HNCs and may signal a sex-specific aetiology in the natural history of infection. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Rachel L. Winer
Full Text Available Cutaneous human papillomaviruses (HPVs have not been evaluated in fingernails from healthy individuals. To determine prevalence and correlates of β-HPVs in fingernails from healthy mid-adult women, we tested archived samples collected from 2011 to 2012 using a multiplex PCR combined with Luminex technology for 46 β-HPV genotypes. One hundred thirteen (61.1% of 185 fingernail samples were positive for β-HPV, and the median number of types detected in positive samples was 2 (interquartile range: 1–4. The most common genotypes detected were HPV-23 (β−2 (13.5%, HPV-38 (β−2 (13.0%, HPV-5 (β−1 (9.2%, HPV-107 (β−2 (8.7%, and HPV-120 (β−2 (8.7%. In multivariate analysis, β-HPV detection was associated with age (prevalence ratio [PR] for women 40–51 years versus 30–39 years = 1.30, 95% CI: 1.05–1.62 and race (PR for non-white versus white race = 0.65, 95% CI: 0.45–0.94. The prevalence of β-HPV in fingernail samples from healthy mid-adult women was similar to the prevalence of β-HPV reported at other cutaneous sites in prior studies. We did not identify any significant health or sexual behavior predictors of β-HPV detection in fingernails. Our results support the hypothesis that fingers may serve as a source of transmission or autoinoculation of cutaneous HPVs to other anatomic sites. Keywords: Fingernails, Women, Beta-HPV, Prevalence, Mid-adult, Risk factor
Full Text Available Bats are reservoirs for many different coronaviruses (CoVs as well as many other important zoonotic viruses. We sampled feces and/or anal swabs of 1,044 insectivorous bats of 2 families and 17 species from 21 different locations within Colorado from 2007 to 2009. We detected alphacoronavirus RNA in bats of 4 species: big brown bats (Eptesicus fuscus, 10% prevalence; long-legged bats (Myotis volans, 8% prevalence; little brown bats (Myotis lucifugus, 3% prevalence; and western long-eared bats (Myotis evotis, 2% prevalence. Overall, juvenile bats were twice as likely to be positive for CoV RNA as adult bats. At two of the rural sampling sites, CoV RNAs were detected in big brown and long-legged bats during the three sequential summers of this study. CoV RNA was detected in big brown bats in all five of the urban maternity roosts sampled throughout each of the periods tested. Individually tagged big brown bats that were positive for CoV RNA and later sampled again all became CoV RNA negative. Nucleotide sequences in the RdRp gene fell into 3 main clusters, all distinct from those of Old World bats. Similar nucleotide sequences were found in amplicons from gene 1b and the spike gene in both a big-brown and a long-legged bat, indicating that a CoV may be capable of infecting bats of different genera. These data suggest that ongoing evolution of CoVs in bats creates the possibility of a continued threat for emergence into hosts of other species. Alphacoronavirus RNA was detected at a high prevalence in big brown bats in roosts in close proximity to human habitations (10% and known to have direct contact with people (19%, suggesting that significant potential opportunities exist for cross-species transmission of these viruses. Further CoV surveillance studies in bats throughout the Americas are warranted.
Osborne, C.; Cryan, P.M.; O'Shea, T.J.; Oko, L.M.; Ndaluka, C.; Calisher, C.H.; Berglund, A.D.; Klavetter, M.L.; Bowen, R.A.; Holmes, K.V.; Dominguez, S.R.
Bats are reservoirs for many different coronaviruses (CoVs) as well as many other important zoonotic viruses. We sampled feces and/or anal swabs of 1,044 insectivorous bats of 2 families and 17 species from 21 different locations within Colorado from 2007 to 2009. We detected alphacoronavirus RNA in bats of 4 species: big brown bats (Eptesicus fuscus), 10% prevalence; long-legged bats (Myotis volans), 8% prevalence; little brown bats (Myotis lucifugus), 3% prevalence; and western long-eared bats (Myotis evotis), 2% prevalence. Overall, juvenile bats were twice as likely to be positive for CoV RNA as adult bats. At two of the rural sampling sites, CoV RNAs were detected in big brown and long-legged bats during the three sequential summers of this study. CoV RNA was detected in big brown bats in all five of the urban maternity roosts sampled throughout each of the periods tested. Individually tagged big brown bats that were positive for CoV RNA and later sampled again all became CoV RNA negative. Nucleotide sequences in the RdRp gene fell into 3 main clusters, all distinct from those of Old World bats. Similar nucleotide sequences were found in amplicons from gene 1b and the spike gene in both a big-brown and a long-legged bat, indicating that a CoV may be capable of infecting bats of different genera. These data suggest that ongoing evolution of CoVs in bats creates the possibility of a continued threat for emergence into hosts of other species. Alphacoronavirus RNA was detected at a high prevalence in big brown bats in roosts in close proximity to human habitations (10%) and known to have direct contact with people (19%), suggesting that significant potential opportunities exist for cross-species transmission of these viruses. Further CoV surveillance studies in bats throughout the Americas are warranted.
Maria D Van Kerkhove
Full Text Available BACKGROUND: The threat posed by highly pathogenic avian influenza A H5N1 viruses to humans remains significant, given the continued occurrence of sporadic human cases (499 human cases in 15 countries with a high case fatality rate (approximately 60%, the endemicity in poultry populations in several countries, and the potential for reassortment with the newly emerging 2009 H1N1 pandemic strain. Therefore, we review risk factors for H5N1 infection in humans. METHODS AND FINDINGS: Several epidemiologic studies have evaluated the risk factors associated with increased risk of H5N1 infection among humans who were exposed to H5N1 viruses. Our review shows that most H5N1 cases are attributed to exposure to sick poultry. Most cases are sporadic, while occasional limited human-to-human transmission occurs. The most commonly identified factors associated with H5N1 virus infection included exposure through contact with infected blood or bodily fluids of infected poultry via food preparation practices; touching and caring for infected poultry; [corrected] exposure to H5N1 via swimming or bathing in potentially virus laden ponds; and exposure to H5N1 at live bird markets. CONCLUSIONS: Research has demonstrated that despite frequent and widespread contact with poultry, transmission of the H5N1 virus from poultry to humans is rare. Available research has identified several risk factors that may be associated with infection including close direct contact with poultry and transmission via the environment. However, several important data gaps remain that limit our understanding of the epidemiology of H5N1 in humans. Although infection in humans with H5N1 remains rare, human cases continue to be reported and H5N1 is now considered endemic among poultry in parts of Asia and in Egypt, providing opportunities for additional human infections and for the acquisition of virus mutations that may lead to more efficient spread among humans and other mammalian species
Full Text Available The antifungal activity of Nepeta rtanjensis Diklić & Milojević essential oil was tested against the human pathogenic fungus Bipolaris spicifera (Bainier Subramanian via mycelial growth assay and conidia germination assay. The minimally inhibitory concentration (MIC of the oil was determined at 1.0 μg ml-1, while the MIC for the antifungal drug Bifonazole in a positive control was determined at 10.0 μg ml-1. The maximum of conidia germination inhibition was accomplished at 0.6 μg ml-1. In addition, at 0.6 μg ml-1 and 0.8 μg ml-1 the oil was able to cause morphophysiological changes in B. spicifera. The most significant result is the bleaching effect of the melanized conidial apparatus of the test fungi, since the melanin is the virulence factor in human pathogenic fungi. These results showed the strong antifungal properties of N. rtanjensis essential oil, supporting its possible rational use as an alternative source of new antifungal compounds.
Novickij, Vitalij; Grainys, Audrius; Svediene, Jurgita; Markovskaja, Svetlana; Paskevicius, Algimantas; Novickij, Jurij
Pathogenic fungi cause many life-threatening infections, especially among individuals with immune system dysfunction. The antifungal drugs commonly used to suppress fungal pathogens can result in long-lasting and toxic therapy. In this work, irreversible electropermeabilization was used to investigate the dynamics of the decrease in Candida albicans colony vitality after application of a pulsed electric field (PEF) and use of antifungal drugs. The fungi were subjected to single 250-µs to 2-ms (0.5-2.5 kV/cm) pulses or repeated short 5-µs pulses, and efficacy was compared. It was shown that electropermeabilization combined with antifungal agents results in rapid and more effective treatment, eliminating more than 90% of C. albicans colony-forming units in a single procedure, which is advantageous in biomedicine. It was also observed that, because of application of PEF and use of the antifungal agents, the Candida cells form cell aggregates and average live cell size is reduced by as much as 53%.
Caballero, Benjamin; Wang, Yipeng; Diaz, Antonio; Tasset, Inmaculada; Juste, Yves Robert; Stiller, Barbara; Mandelkow, Eva-Maria; Mandelkow, Eckhard; Cuervo, Ana Maria
Loss of neuronal proteostasis, a common feature of the aging brain, is accelerated in neurodegenerative disorders, including different types of tauopathies. Aberrant turnover of tau, a microtubule-stabilizing protein, contributes to its accumulation and subsequent toxicity in tauopathy patients' brains. A direct toxic effect of pathogenic forms of tau on the proteolytic systems that normally contribute to their turnover has been proposed. In this study, we analyzed the contribution of three different types of autophagy, macroautophagy, chaperone-mediated autophagy, and endosomal microautophagy to the degradation of tau protein variants and tau mutations associated with this age-related disease. We have found that the pathogenic P301L mutation inhibits degradation of tau by any of the three autophagic pathways, whereas the risk-associated tau mutation A152T reroutes tau for degradation through a different autophagy pathway. We also found defective autophagic degradation of tau when using mutations that mimic common posttranslational modifications in tau or known to promote its aggregation. Interestingly, although most mutations markedly reduced degradation of tau through autophagy, the step of this process preferentially affected varies depending on the type of tau mutation. Overall, our studies unveil a complex interplay between the multiple modifications of tau and selective forms of autophagy that may determine its physiological degradation and its faulty clearance in the disease context. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.
Biagini, Massimiliano; Garibaldi, Manuela; Aprea, Susanna; Pezzicoli, Alfredo; Doro, Francesco; Becherelli, Marco; Taddei, Anna Rita; Tani, Chiara; Tavarini, Simona; Mora, Marirosa; Teti, Giuseppe; D'Oro, Ugo; Nuti, Sandra; Soriani, Marco; Margarit, Immaculada; Rappuoli, Rino; Grandi, Guido; Norais, Nathalie
Bacterial lipoproteins are attractive vaccine candidates because they represent a major class of cell surface-exposed proteins in many bacteria and are considered as potential pathogen-associated molecular patterns sensed by Toll-like receptors with built-in adjuvanticity. Although Gram-negative lipoproteins have been extensively characterized, little is known about Gram-positive lipoproteins. We isolated from Streptococcus pyogenes a large amount of lipoproteins organized in vesicles. These vesicles were obtained by weakening the bacterial cell wall with a sublethal concentration of penicillin. Lipid and proteomic analysis of the vesicles revealed that they were enriched in phosphatidylglycerol and almost exclusively composed of lipoproteins. In association with lipoproteins, a few hypothetical proteins, penicillin-binding proteins, and several members of the ExPortal, a membrane microdomain responsible for the maturation of secreted proteins, were identified. The typical lipidic moiety was apparently not necessary for lipoprotein insertion in the vesicle bilayer because they were also recovered from the isogenic diacylglyceryl transferase deletion mutant. The vesicles were not able to activate specific Toll-like receptor 2, indicating that lipoproteins organized in these vesicular structures do not act as pathogen-associated molecular patterns. In light of these findings, we propose to name these new structures Lipoprotein-rich Membrane Vesicles. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.
Al-Jarbou, Ahmed Nasser
Bacterial pathogenesis presents an astounding arsenal of virulence factors that allow them to conquer many different niches throughout the course of infection. Principally fascinating is the fact that some bacterial species are able to induce different diseases by expression of different combinations of virulence factors. Nevertheless, studies aiming at screening for the presence of bacteriophages in humans have been limited. Such screening procedures would eventually lead to identification of phage-encoded properties that impart increased bacterial fitness and/or virulence in a particular niche, and hence, would potentially be used to reverse the course of bacterial infections. As the human oral cavity represents a rich and dynamic ecosystem for several upper respiratory tract pathogens. However, little is known about virus diversity in human dental plaque which is an important reservoir. We applied the culture-independent approach to characterize virus diversity in human dental plaque making a library from a virus DNA fraction amplified using a multiple displacement method and sequenced 80 clones. The resulting sequence showed 44% significant identities to GenBank databases by TBLASTX analysis. TBLAST homology comparisons showed that 66% was viral; 18% eukarya; 10% bacterial; 6% mobile elements. These sequences were sorted into 6 contigs and 45 single sequences in which 4 contigs and a single sequence showed significant identity to a small region of a putative prophage in the Corynebacterium diphtheria genome. These findings interestingly highlight the uniqueness of over half of the sequences, whilst the dominance of a pathogen-specific prophage sequences imply their role in virulence.