Public Health Risk of Foodborne Pathogens in Edible African Land Snails, Cameroon.

In tropical countries, land snails are an important food source; however, foodborne disease risks are poorly quantified. We detected Campylobacter spp., Yersinia spp., Listeria spp., Salmonella spp., or Shiga-toxigenic Escherichia coli in 57%-86% of snails in Cameroon. Snail meat is a likely vector for enteric diseases in sub-Saharan Africa countries.

Delivering the pain: an overview of the type III secretion system with special consideration for aquatic pathogens.

Gram-negative bacteria are known to subvert eukaryotic cell physiological mechanisms using a wide array of virulence factors, among which the type three-secretion system (T3SS) is often one of the most important. The T3SS constitutes a needle-like apparatus that the bacterium uses to inject a diverse set of effector proteins directly into the cytoplasm of the host cells where they can hamper the host cellular machinery for a variety of purposes. While the structure of the T3SS is somewhat conserved and well described, effector proteins are much more diverse and specific for each pathogen. The T3SS can remodel the cytoskeleton integrity to promote intracellular invasion, as well as silence specific eukaryotic cell signals, notably to hinder or elude the immune response and cause apoptosis. This is also the case in aquatic bacterial pathogens where the T3SS can often play a central role in the establishment of disease, although it remains understudied in several species of important fish pathogens, notably in Yersinia ruckeri. In the present review, we summarise what is known of the T3SS, with a special focus on aquatic pathogens and suggest some possible avenues for research including the potential to target the T3SS for the development of new anti-virulence drugs.

A Survey of Antimicrobial Resistance Determinants in Category A Select Agents, Exempt Strains, and Near-Neighbor Species.

A dramatic increase in global antimicrobial resistance (AMR) has been well documented. Of particular concern is the dearth of information regarding the spectrum and prevalence of AMR within Category A Select Agents. Here, we performed a survey of horizontally and vertically transferred AMR determinants among Category A agents and their near neighbors. Microarrays provided broad spectrum screening of 127 Francisella spp., Yersinia spp., and Bacillus spp. strains for the presence/absence of 500+ AMR genes (or families of genes). Detecting a broad variety of AMR genes in each genus, microarray analysis also picked up the presence of an engineered plasmid in a Y. pestis strain. High resolution melt analysis (HRMA) was also used to assess the presence of quinolone resistance-associated mutations in 100 of these strains. Though HRMA was able to detect resistance-causing point mutations in B. anthracis strains, it was not capable of discriminating these point mutations from other nucleotide substitutions (e.g., arising from sequence differences in near neighbors). Though these technologies are well-established, to our knowledge, this is the largest survey of Category A agents and their near-neighbor species for genes covering multiple mechanisms of AMR.

Prevalence, characterization, and antimicrobial resistance of Yersinia species and Yersinia enterocolitica isolated from raw milk in farm bulk tanks.

The aims of this study were to investigate the prevalence and to characterize and determine the antibiotic resistance of Yersinia spp. isolates from raw milk. From September 2008 to August 2010, 446 raw milk samples were obtained from farm bulk milk tanks in Varamin, Iran. Yersinia spp. were detected in 29 (6.5%) samples, out of which 23 (79.3%), 5 (17.2%), and 1 (3.4%) were isolated from cow, sheep, and goat raw milk, respectively. The most common species isolated was Yersinia enterocolitica (65.5%), followed by Yersinia frederiksenii (31%), and Yersinia kristensenii (3.4%). Of the 19 Y. enterocolitica isolates, 14 (73.7%) were grouped into bioserotype 1A/O:9, 4 (21.1%) belonged to bioserotype 1B:O8, 1 (5.3%) belonged to bioserotype 4/O:3, and 1 isolate (biotype 1A) was not typable. All the isolates of biotypes 1B and 4harbored both the ystA and ail genes. However, all the isolates of biotype 1A were only positive for the ystB gene. The tested Yersinia spp. showed the highest percentages of resistance to tetracycline (48.3%), followed by ciprofloxacin and cephalothin (each 17.2%), ampicillin (13.8%), streptomycin (6.9%), and amoxicillin and nalidixic acid (each 3.4%). All of the tested isolates demonstrated significant sensitivity to gentamicin and chloramphenicol. Recovery of potentially pathogenic Y. enterocolitica from raw milk indicates high risks of yersiniosis associated with consumption of raw milk.

Prevalence and antimicrobial resistance of Listeria, Salmonella, and Yersinia species isolates in ducks and geese.

The aims of this study were to determine the prevalence and antimicrobial resistance of Listeria, Salmonella, and Yersinia spp. isolated from duck and goose intestinal contents. A total of 471 samples, including 291 duck and 180 goose intestinal contents, were purchased from wet markets between November 2008 and July 2010. Listeria, Salmonella, and Yersinia spp. were isolated from 58 (12.3%), 107 (22.7%), and 80 (17%) of the samples, respectively. It was concluded that Listeria ivanovii, Salmonella Thompson, and Yersinia enterocolitica were the predominant serovars among Listeria, Salmonella, and Yersinia spp., respectively. Moreover, resistance to tetracycline was common in Listeria (48.3%) and Salmonella spp. (63.6%), whereas 51.3% of the Yersinia spp. isolates were resistant to cephalothin. Therefore, continued surveillance of the prevalence of the pathogens and also of emerging antibiotic resistance is needed to render possible the recognition of foods that may represent risks and also ensure the effective treatment of listeriosis, salmonellosis, and yersiniosis.

Detection of Yersinia enterocolitica, Shigella spp. and Salmonella spp. in Rattus norvegicus captured from Tehran, Iran.

Background: The present study aims to determine the presence of Yersinia spp., Yersinia pestis, Yersinia enterocolitica pathogen, Listeria monocytogenes, Salmonella spp., Shigella spp., Francisella tularensis and Borrelia spp. in brown rats of Tehran, Iran. Methods: PCR was used to detect various bacteria in 100 brown rats, Also, ELISA was used to detect antibodies against the F. tularensis and Borrelia spp. Results: A total of 16% and 13% of fecal samples were positive for Yersinia spp. and Y. enterocolitica pathogen. ELISA results were negative for F. tularensis and Borrelia. No specific antibodies (IgG) were against these bacteria. Conclusion: According to the results of our analysis, rats are significant transmitters and carriers of a variety of illnesses that can spread to both people and other animals.

Yersinia enterocolitica Bacteremia Associated with a Ruptured Abdominal Aortic Aneurysm: A Case Report with Literature Review.

Yersinia enterocolitica is a foodborne pathogen, mainly associated with disorders involving the gastrointestinal tract, including diarrhea, ileitis, and mesenteric lymphadenitis. Extraintestinal presentation is uncommon in healthy individuals, but bacteremia is reported in immunocompromised hosts. We present a 74-year-old male with Y. enterocolitica serogroup O:3 bacteremia who complicated to rupture of an abdominal aortic aneurysm. With the current case report, we aimed to emphasize the association of Y. enterocolitica bacteremia with abdominal aortic aneurysm rupture. Better surveillance is needed, not only to reduce morbidity and mortality but also to update current epidemiological data on the incidence of such associations.

Antimicrobial Activity and Chemical Composition of Essential Oils against Pathogenic Microorganisms of Freshwater Fish.

Antimicrobials are widely applied in aquaculture for treatment of infectious diseases in fish. The increased antimicrobial resistance of fish pathogens to conventional antimicrobial treatment highlights the need for research on the antibacterial properties of natural products-in this case, essential oils (EOs). The aim of the present study was to detect the antimicrobial activity of the essential oils on pathogenic microorganisms found in freshwater fish. Freshwater fish isolates of Aerococcus spp., Aeromonas spp., Enterococcus spp., Escherichia spp., Pseudomonas spp., Shewanella spp., Yersinia spp., and Vagococcus spp. were tested for antimicrobial resistance and antimicrobial activity against 14 commercially available essential oils. Antimicrobial resistance was identified in Pseudomonas spp. isolates against cefepime and ciprofloxacin; while all Aeromonas, Enterococcus, and Yersinia isolates were fully susceptible. All tested EOs revealed antimicrobial activity against the tested freshwater fish isolates at different extents. Cinnamomum camphora exhibited strong antimicrobial activity against Aeromonas spp. (3.12 µL/mL), Enterococcus spp. (0.78-1.56 µL/mL), and Pseudomonas spp. with the MIC method. EOs of Gaultheria procumbens and Litsea cubeba showed strong antibacterial activity against Yersinia spp. and Vacococcus spp. (6.25 µL/mL). The study shows the antimicrobial activity of EOs against the most relevant freshwater fish pathogens and indicates the application opportunities in aquaculture.

Two copies of the ail gene found in Yersinia enterocolitica and Yersinia kristensenii.

Yersinia enterocolitica is the most common Yersinia species causing foodborne infections in humans. Pathogenic strains carry the chromosomal ail gene, which is essential for bacterial attachment to and invasion into host cells and for serum resistance. This gene is commonly amplified in several PCR assays detecting pathogenic Y. enterocolitica in food samples and discriminating pathogenic isolates from non-pathogenic ones. We have isolated several non-pathogenic ail-positive Yersinia strains from various sources in Finland. For this study, we selected 16 ail-positive Yersinia strains, which were phenotypically and genotypically characterised. Eleven strains were confirmed to belong to Y. enterocolitica and five strains to Yersinia kristensenii using whole-genome alignment, Parsnp and the SNP phylogenetic tree. All Y. enterocolitica strains belonged to non-pathogenic biotype 1A. We found two copies of the ail gene (ail1 and ail2) in all five Y. kristensenii strains and in one Y. enterocolitica biotype 1A strain. All 16 Yersinia strains carried the ail1 gene consisting of three different sequence patterns (A6-A8), which were highly similar with the ail gene found in high-pathogenic Y. enterocolitica biotype 1B strains (A2). The Ail protein encoded by the ail1 gene was highly conserved compared to the Ail protein encoded by the ail2 gene. Multiple sequence alignment of the ail gene and Ail protein were conducted with MAFF. In total, 10 ail sequence variations have been identified, of which 8 conserved ones belonged to the ail1 gene. According to our results, the detection of ail alone is not sufficient to predict the pathogenicity of Yersinia isolates.

European Brown hare (Lepus europaeus) as a source of emerging and re-emerging pathogens of Public Health importance: A review.

European brown hare (Lepus europaeus, EBH) is probably the most important game animal in Europe throughout its historical distribution. The decline in its populations across its geographic range in Europe have been attributed to factors such as reproductive rate and the ability for adaptation, climate, feed availability, predators, anthropogenic factors and diseases. Apart from common diseases of hares with a high impact on their mortality such as European Brown hare Syndrome, EBH has been involved in the epidemiology of pathogens with zoonotic potential. In this work, the role of EBH as a source of Crimean-Congo haemorrhagic fever virus (CCHFV), Hepatitis E virus (HEV), Yersinia spp., Brucella spp., Francisella tularensis, Toxoplasma gondii and Leishmania infantum is discussed. Hares may significantly contribute to the epidemiology of important emerging zoonotic pathogens through maintenance of high endemicity levels as in the case of CCHFV, as a reservoir of important pathogens such as Yersinia spp., B. suis, F. tularensis and L. infantum and as a potential source of T. gondii for other animals, especially for carnivores but also for humans. However, EBH may also be a host of minor importance as in the case of HEV. The continuous surveillance of hare populations will enable the collection of information on the population health status and the pathogens currently circulating in the area posing risk for wildlife, domestic animals and humans. The possible live animal translocations of infected hares, the fact that this species acts as a host of vectors (fleas, ticks, mosquitoes and sandflies) and the prey of carnivores and omnivores that travel in great distances getting into contact with domestic animals and humans, further highlights the need to be included in surveillance studies. Besides, the hunter-harvested EBH population is an excellent indicator for recent pathogen transmission due to its short lifespan.