Prevalence of nontyphoidal Salmonella serogroups and their antimicrobial resistance patterns in a university teaching hospital in Eastern Province of Saudi Arabia

Salmonella in the food chain within the Gulf Cooperation Council countries

Infections caused by bacteria originating from tainted food sources are a widespread concern due to their large economic impact and detrimental effects on public health. We aimed to explore literature focusing on the presence of Salmonella in the food supply chains of Gulf Cooperation Council (GCC) countries and to provide an overview of available information concerning health-related issues and the status of salmonellosis in humans in GCC countries. The reviewed evidence underscored a gap in our comprehensive understanding of the prevalence of Salmonella in the food supply of GCC countries. Molecular characterization efforts to pinpoint the sources of Salmonella in these nations were limited. Surveys targeting Salmonella in the food supply of GCC countries have been infrequent. While qualitative data indicated the presence or absence of Salmonella, there was a noticeable lack of quantitative data detailing the actual quantities of these bacteria in chicken meat supplies across GCC countries. Although reports regarding Salmonella in animal-derived foods were common, the literature highlighted in this review emphasized the persistent challenge that Salmonella pose to food safety and public health in GCC countries. Addressing this issue requires concerted efforts to enhance surveillance, improve control measures, and promote greater awareness among stakeholders in the food supply chain.

Diversity and antimicrobial susceptibility patterns of clinical and environmental Salmonella enterica serovars in Western Saudi Arabia

The diverse environmental distribution of Salmonella makes it a global source of human gastrointestinal infections. This study aimed to detect Salmonella spp. and explore their diversity and antimicrobial susceptibility patterns in clinical and environmental samples. Pre-enrichment, selective enrichment, and selective plating techniques were adopted for the Salmonella detection whereas the API 20E test and Vitek Compact 2 system were used to confirm the identity of isolates. Salmonella serovars were subjected to molecular confirmation by 16S rDNA gene sequencing. Disc diffusion method and Vitek 2 Compact system determined the antibiotic susceptibility of Salmonella serovars. Multiple antibiotic resistance index (MARI) was calculated to explore whether Salmonella serovars originate from areas with heavy antibiotic usage. Results depicted low Salmonella prevalence in clinical and environmental samples (3.5%). The main detected serovars included Salmonella Typhimurium, S. enteritidis, S. Infantis, S. Newlands, S. Heidelberg, S. Indian, S. Reading, and S. paratyphi C. All the detected Salmonella serovars (27) exhibited multidrug resistance to three or more antimicrobial classes. The study concludes that the overall Salmonella serovars prevalence was found to be low in environmental and clinical samples of Western Saudi Arabia (Makkah and Jeddah). However, antimicrobial susceptibility patterns of human and environmental Salmonella serovars revealed that all isolates exhibited multidrug-resistance (MDR) patterns to frequently used antibiotics, which might reflect antibiotic overuse in clinical and veterinary medicine. It would be suitable to apply and enforce rules and regulations from the One Health approach, which aim to prevent antibiotic resistance infections, enhance food safety, and improve human and animal health, given that all Salmonella spp. detected in this investigation were exhibiting MDR patterns.

Serotype Occurrence, Virulence Profiles, Antimicrobial Resistance and Molecular Characterization of Salmonella Isolated from Hospitalized Patients with Gastroenteritis in Great Tunisia between 2010 and 2020

Non-typhoid Salmonella is one of the major causes of food-borne infections worldwide. The aim of the current study is to determine the serotype occurrence, virulence factors and antimicrobial resistance patterns of Salmonella isolated from hospitalized patients. The identification of Salmonella strains was performed according to REMIC, 2018. The susceptibility of Salmonella isolates was assessed against 20 antimicrobials using the disk diffusion method. Some virulence and antimicrobial resistance genes were identified using PCR. Among the 61 isolated Salmonella strains, seven serotypes were identified and all were positive for the virulence genes invA, mgtC and sirA. Critical resistance rates (>40%) were detected for tetracycline, nalidixic acid, amoxicillin and fluoroquinolones. However, resistances to ertapenem, ceftazidim, aztreonam and colistin were null. In addition, 33% of the isolated strains were multidrug-resistant (MDR). Moreover, 80% and 60% of S. Kentucky isolates were identified as fluoroquinolone-resistant and MDR strains, respectively. The qnrB gene was amplified in 63.2% of fluoroquinolone-resistant strains. The dfrA1 gene was identified in 20% (4/20) of the trimethoprim-sulfamethoxazole resistant strains and the integrase Class 2 gene was amplified in only 8.2% (5/61) of the isolates. Our findings highlight the emergence of MDR Salmonella isolates. A rationalization of antimicrobial use is urgently recommended in both human and veterinary medicine.

Diagnostic yield of stool culture and probable predictive factors

BACKGROUND AND AIM

Stool analysis is commonly performed to diagnose certain gastrointestinal diseases. The diagnostic yield of stool culture,  a method of stool analysis, is variable worldwide and is unclear in the Kingdom of Saudi Arabia. This study was conducted to determine the diagnostic yield of stool culture from the year 2008 to 2020 and to determine the predictors for a positive stool culture. Furthermore, antibiotic susceptibility patterns of the detected copro-pathogens in the same time period were collected and studied.

METHODS

This is a retrospective case-control study in which patients' data was collected from the hospital's electronic health record. The results of all stool analyses performed from 2008 to 2020 and associated patients' characteristics were collected.  Characteristics of cases with a positive stool culture were compared to the characteristics of those without to identify the predictors for positive stool cultures.

RESULTS

Copro-pathogens were detected in 89.4% of cultured stool samples. Salmonella spp (1590/1775, 89.6%) was the most common organism followed by Shigella spp. (84/1775, 4.7%) and Campylobacter spp (45/1775, 2.5%). Male sex, the 1-5 age group, positive fecal occult blood test results, and positive stool leukocyte test results were associated with a positive stool culture result. Cultured copro-pathogens were highly sensitive to Trimethoprim/Sulfamethoxazole and Ampicillin.

CONCLUSIONS

Stool analysis was found to be a test of high diagnostic yield. However, there is still a need for more studies on this subject with a focus on possible predictive factors for specific organisms.

Epidemiology, Serogroups and Resistance of Salmonella During a 15-Year Period (2006-2020) in Kuwait

Purpose

The aim of the study was to investigate the changing pattern in serogroup distribution and antimicrobial resistance of all Salmonella spp. isolated from patients attending the Mubarak Al Kabeer Hospital (MAK), Kuwait from 2006 to 2020.

Patients and Methods

A retrospective study of all enrolled patients attending the MAK with culture-positive Salmonella spp. was undertaken. Data on age, gender, culture sample and serogroup were obtained from the laboratory information system. A prospective antimicrobial susceptibility of all stock isolates was carried out using E test. The trend rates of Salmonella serogroups and antimicrobial resistance were compared among 5 periods: 2006–2008, 2009–2011, 2012–2014, 2015–2017, and 2018–2020.

Results

A total of 700 isolates were identified. The majority of the isolates were from the stool (77.6%), followed by the blood (16.4%). The most common serogroups were serogroup D (37.6%) and B (23.4%). There was a significant rise in ciprofloxacin resistance from 32.2% during 2006–2008 to 54.3% during 2018–2020 and from 32.5% during 2009–2011 to 54.3% during 2018–2020 (P=0.0001, respectively). The resistance trend to cefotaxime was at relatively low levels ranging from 0% to 3.4% through 2006–2008 to 2018–2020. There was a significant drop of the resistance to ampicillin from 23.6% in 2015–2017 to 12.3% in 2006–2008 to 2018–2020 (P=0.03). Trimethoprim/sulfamethoxazole resistance dropped significantly from 14.5 to 3.6% (P=0.002) during 2006–2008 to 2018–2020 and then from 13.5 to 3.6% (P=0.02) during 2015–2017 to 2018–2020. One hundred and seventeen (16.7%) isolates were multidrug-resistant.

Conclusion

Continuous surveillance of Salmonella and its antimicrobial resistance is important for antibiotic policy formulation for invasive Salmonella infections.

Five-year resistance trends in pathogens causing healthcare-associated infections at a multi-hospital healthcare system in Saudi Arabia, 2015-2019

OBJECTIVES

Awareness of antimicrobial resistance (AMR) patterns in a given healthcare setting is important to inform the selection of appropriate antimicrobial therapy to reduce the further rise and spread of AMR as well as the rate of healthcare-associated infections (HAIs) and multidrug-resistant (MDR) organisms. We aimed to describe resistance patterns to several antimicrobial agents in pathogens causing HAIs isolated from patients using data gathered at three private tertiary-care hospitals in Saudi Arabia.

METHODS

Data on trends in AMR among bacteria causing HAIs and MDR events in children and adults at three private hospitals were collected retrospectively (2015-2019) using surveillance data.

RESULTS

Over the 5-year period, 29 393 pathogens caused 17 539 HAIs in 15 259 patients. Approximately 57.3% of patients were female and the mean age was 38.4 ± 16.8 years (81.4% adults, 18.6% children). Gram-negative pathogens were four times more likely to cause HAIs compared with Gram-positive bacteria (79.3% vs. 20.7%). Ranking of causative pathogens in decreasing order was Escherichia coli (42.2%), Klebsiella spp. (16.8%) and Staphylococcus aureus (13.9%). Acinetobacter spp. were the only pathogens to decrease significantly (7% reduction; P = 0.033). The most common resistant pathogens were extended-spectrum cephalosporin-resistant E. coli (37.1%), extended-spectrum cephalosporin-resistant Klebsiella (27.8%), carbapenem-non-susceptible Acinetobacter spp. (19.5%), carbapenem-non-susceptible Pseudomonas aeruginosa (19.2%) and methicillin-resistant S. aureus (18.6%).

CONCLUSION

National collaboration is required by prompt feedback to local authorities to tackle regional differences in AMR. This can help plan timely containment interventions to stop and contain microbial threats and swiftly assess their impact.

Pattern of increased antimicrobial resistance of Salmonella isolates in the Eastern Province of KSA

OBJECTIVES

The antimicrobial resistance of Salmonella species is increasing worldwide. This study was conducted to determine the pattern of antimicrobial susceptibility of Salmonella species in a tertiary hospital from 2011 to 2018.

METHODS

In this retrospective study, the medical records of all patients with Salmonella infections were reviewed. The clinical, demographic, and microbiological data of the selected patients were analysed.

RESULTS

A total of 752 patients were included. The resistance of Salmonella species to antimicrobial drugs increased from 24.6% in 2011 to 37.8% in 2018 (p = 0.002). By 2018 all Salmonella isolates were completely resistant to cefalotin, cefuroxime, and cefoxitin, while we found some susceptibility to other cephalosporins and ciprofloxacin. The most commonly isolated Salmonella serogroups were groups D (36.5%), C (23.5%), and B (11.7%).

CONCLUSIONS

The incidence of resistance of Salmonella to antibiotics is on the rise. The results of this study highlight the need for an active monitoring system of antibiotic usage in humans and domestic animals.

Identification of Salmonella Bredeney Resistant to Third-Generation Cephalosporins in Saudi Arabia

The rapidly increasing prevalence and spread of antibiotic-resistant Salmonella worldwide have become a thorny problem that poses a serious threat to human health. It is speculated that antibiotic abuse, frequent traveling, and mass gatherings accelerate this threat. To explore this hypothesis, we investigated 13 Salmonella isolates from Medina, Saudi Arabia and 15 from China as the control group using typical methods of serotype identification, antibiotic resistance tests, pulsed-field gel electrophoresis (PFGE), and multi-locus sequence typing (MLST). Our results indicated that the isolates from China showed greater serotype diversity and a higher antimicrobial resistance rate, which was consistent with results from other studies in China. In contrast, the Saudi Arabian isolates were mainly identified as Serovar Bredeney and were resistant to a limited number of antibiotics. Interestingly, two of the Bredeney isolates was resistant to third-generation cephalosporins but sensitive to all other tested antibiotics. To confirm the results and understand the underlying molecular mechanisms of these isolates, whole-genome sequencing (WGS) was performed. We discovered that several cephalosporin resistance-associated genes were shared with other strains, but one gene (LEN-23) was unique. Therefore, to the best of our knowledge, we concluded that this study is the first to report the emergence of Salmonella Bredeney resistant to third-generation cephalosporins in Saudi Arabia.

Prevalence of enteric non-typhoidal Salmonella in humans in the Middle East and North Africa: A systematic review and meta-analysis

To enhance efforts related to controlling foodborne pathogens in the Middle East and North Africa (MENA), information on epidemiology of non-typhoidal Salmonella enterica (hereafter termed "Salmonella") is limited. We quantified the overall regional and country-specific Salmonella prevalence in different human populations and identified the most common serotypes. Published literature of Salmonella prevalence was systematically reviewed and reported following the Preferred Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Pooled Salmonella prevalence measures were estimated using a random-effects model. We identified 46 research reports that reported 84 Salmonella prevalence measures in 15 out of 24 countries in MENA. There were 252,831 tested humans with 6,356 Salmonella-positive cases. The pooled Salmonella prevalence in MENA was estimated at 6.6% (95% confidence interval (CI): 5.4%-7.9%). The highest pooled Salmonella prevalence measures were in Morocco (17.9%, 95% CI: 5.7%-34.8%, 1997-2012), Tunisia (10.2%, 95% CI: 4.3%-18.0%, 1988-2009) and Sudan (9.2%, 95% CI: 6.5%-12.2%, 2006-2008), while the lowest were in Jordan (1.1%, 95% CI: 0.1%-3.0%, 1993-2010), Oman (1.2%, 95% CI: 1.2%-1.3%, 1998-2002) and Palestine (1.2%, 95% CI: 0.4%-2.1%, 1999-2011). In MENA, Salmonella pooled prevalence in gastrointestinal symptomatic, gastrointestinal asymptomatic and food handlers population groups was 13.0% (95% CI: 7.6%-19.6%), 11.4% (95% CI: 2.2%-25.7%) and 3.8% (95% CI: 1.0%-8.0%), respectively. Salmonella prevalence was 14.5% (95% CI: 8.7%-26.1%) in studies tested <100 subjects, whereas 4.6% (95% CI: 3.6%-5.8%) in studies tested ≥100 subjects. Salmonella Enteritidis (29.8%) and Typhimurium (23.6%) were the most common serotypes. Salmonella was a common foodborne pathogen in MENA countries, particularly in North African countries. Findings inform the scientific community, the public and the decision-makers with Salmonella prevalence and gaps in evidence in MENA to support control and prevention strategies and could leverage more research studies.

Epidemiology of common resistant bacterial pathogens in the countries of the Arab League

No uniformly organised collection of data regarding antimicrobial resistance has occurred in the countries of the Arab League. 19 countries of the Arab League have published data for antimicrobial susceptibility for the WHO priority organisms, and seven of 14 of these organisms are included in this Review (Escherichia coli, Klebsiella spp, Pseudomonas aeruginosa, Acinetobacter baumannii, Salmonella spp, Staphylococcus aureus, and Streptococcus pneumoniae). Although E coli and Klebsiella spp resistance to third-generation cephalosporins is common in all countries, with prevalence reaching more than 50% in Egypt and Syria, carbapenem resistance is emerging, albeit with a prevalence of less than 10%. Conversely, a large amount of carbapenem resistance has been reported for P aeruginosa and A baumannii across the Arab League, reaching 50% and 88% of isolates in some countries. As for Salmonella spp, the prevalence of fluoroquinolone resistance has exceeded 30% in several areas. With regards to the Gram-positive pathogens, the prevalence of meticillin resistance in S aureus is reported to be between 20% and 30% in most countries, but exceeds 60% in Egypt and Iraq. The prevalence of penicillin non-susceptibility among pneumococci has reached more than 20% in Algeria, Egypt, Morocco, Saudi Arabia, and Tunisia. These findings highlight the need for structured national plans in the region to target infection prevention and antimicrobial stewardship.

Changes in epidemiology and antimicrobial susceptibility of nontyphoid Salmonella in children in southern Taiwan, 1997-2016

BACKGROUND

This study aimed to investigate the changing trends in serogroup distribution and antimicrobial susceptibility of nontyphoid Salmonella (NTS) isolated from children in the past two decades in Taiwan.

METHODS

This retrospective study enrolled patients aged younger than 18 years with culture-proven NTS infection in a tertiary medical center from 1997 to 2016. Data on age, Salmonella serogroup, culture sample, and antimicrobial susceptibility were obtained from medical records. The rates of Salmonella serogroups and antimicrobial resistance were compared between period 1 (1997-2006) and period 2 (2007-2016).

RESULTS

A total of 2075 NTS isolates were identified from 1997 to 2016 (1036 in period 1, 1039 in period 2). The major isolates were from feces (89.1%) and blood (10.4%). The most common serogroup was serogroup B (54.8%), followed by serogroup D (18.8%). There was a significant decline in the proportion of serogroup B with a concomitant rise in serogroup D in the past two decades. In period 2, resistance to cefotaxime and cefixime increased remarkably among serogroup B, whereas resistance to ampicillin increased notably among serogroup D. Furthermore, the incidence of multidrug-resistant (≥3 antibiotics) NTS significantly decreased in both serogroup B and serogroup D in period 2.

CONCLUSION

This study revealed a significant rise in serogroup D with a concomitant decline in serogroup B NTS infection in Taiwanese children. Moreover, antimicrobial resistance to third-generation cephalosporins increased in serogroup B. Continuous surveillance of NTS serogroup distribution and antimicrobial susceptibility is mandatory to formulate therapeutic strategies for NTS infections.

Foodborne disease and food control in the Gulf States

Gulf States in the Middle East have had to change rapidly from subsidence herding, farming and fishing communities to modern states through the exploitation of revenue-generating petroleum products. Fresh water is an even more precious commodity than oil today as this is seen as a rapidly diminishing resource through over use of aquifers with scarce and unpredictable rainfall not replenishing the needs of these countries which increasing rely on reverse-osmosis (RO) desalination of seawater but at a cost in terms of energy. Recycling of waste water and sewage is carried out and used to water urban landscaping and some crops, but there are risks of the presence of pathogens. Much food today is imported to satisfy the requirements of expanding populations, especially foreign workers on temporary visas who make up more than half the residents in many of these Gulf States. Despite limited published data on Gulf States regarding enteric and foodborne diseases and their prevention and control, profiles emerge that can describe the current situation and some future directions. Gastrointestinal diseases, such as typhoid, cholera, and amebic dysentery can be brought into these countries through workers returning from endemic regions, and also through refugees from conflict-torn neighboring countries. However, some diseases are endemic like brucellosis and fatal illnesses from the newly identified Middle East Respiratory Corona Virus (MERS-CoV) associated with camels. In the 1990s, coalition troops stationed during the Gulf War brought in external suppliers and caterers, but using local products like chickens with troops occasionally suffering from infections. The hot climate, particularly in summer, can allow rapid growth of pathogens in foods, especially where refrigeration is not available as in home-prepared lunches by workers and during transportation of foods across traffic-congested cities. One of the biggest concerns for Saudi Arabia is the health oversight of millions during the annual Hajj, and despite much care over restriction of infected pilgrims and care of food, occasional outbreaks have been reported. Government agencies are particularly concerned about restaurant food and try and follow up on complaints of customers but rarely are agents identified; those that have include Salmonella, Bacillus cereus and Staphylococcus aureus. Implicated foods include ethnic products such as Turkish menu items and shawarma. Local culture may play a role in allowing growth of pathogens such as serving women after men at weddings. However, deaths that have been attributed to microbial sources may have been caused by illegal use of pesticides such as aluminum phosphide. Severe penalties have been applied to owners and staff implicated in outbreaks including fines, jail sentences and deportations, which are not typical of Western nations. However, some agencies have initiatives to help educate and train foreign workers in several languages. Foodborne disease surveillance systems are generally not adequate though some countries have initiated modernization of inspection approaches and laboratories. Consumer surveys show that residents have some knowledge of foodborne disease but this could be improved especially for women who do most of the shopping and food preparation in homes. Agencies are increasing directing campaigns for general food safety in their populations, and as long as resources are available, food control is likely to improve over time in Gulf States which is good news for visitors, expatriate workers and citizens alike.

Occurrence and antimicrobial resistance of pathogenic Escherichia coli and Salmonella spp. in retail raw table eggs sold for human consumption in Enugu state, Nigeria

AIM

This study was conducted to investigate the occurrence of pathogenic Escherichia coli and Salmonella species in retail raw table eggs sold for human consumption in Enugu State and to determine the resistance of these pathogens to antimicrobials commonly used in human and veterinary practices in Nigeria.

MATERIALS AND METHODS

A total of 340 raw table eggs comprising 68 composite samples (5 eggs per composite sample) were collected from five selected farms (13 composite samples from the farms) and 10 retail outlets (55 composite samples from the retail outlets) in the study area over a period of 4-month (March-June, 2014). The eggs were screened for pathogenic E. coli and Salmonella species following standard procedures within 24 h of sample collection. Isolates obtained were subjected to in-vitro antimicrobial susceptibility test with 15 commonly used antimicrobials using the disk diffusion method.

RESULTS

About 37 (54.4%) and 7 (10.3%) of the 68 composite samples were positive for pathogenic E. coli and Salmonella species, respectively. The shells showed significantly higher (p<0.05) contaminations than the contents for both microorganisms. The eggs from the farms showed higher contamination with pathogenic E. coli than eggs from the retail outlets while the reverse was the case for Salmonella species even though they were not significant (p>0.05). The organisms obtained showed a multiple drug resistance. They were completely resistant to nitrofurantoin, sulfamethoxazole/trimethoprim, penicillin G and oxacillin. In addition to these, Salmonella spp. also showed 100% resistance to tetracycline. The pathogenic E. coli isolates obtained were 100% susceptible to gentamicin, neomycin, ciprofloxacin, and amoxicillin-clavulanic acid while Salmonella spp. showed 100% susceptibility to erythromycin, neomycin, and rifampicin. Both organisms showed varying degrees of resistance to streptomycin, amoxicillin, vancomycin, and doxycycline.

CONCLUSION

From the results of the study, it can be concluded that the raw table eggs marketed for human consumption in Enugu State, Nigeria is contaminated with pathogenic E. coli and Salmonella species that showed multiple drug resistance to antimicrobial agents commonly used in veterinary and human practice.

Multiplex Polymerase Chain Reaction for Detection of Gastrointestinal Pathogens in Migrant Workers in Qatar

The causes of infectious diarrhea among the migrant worker population in Qatar are not well understood. We conducted a prospective observational study to understand the demographic and clinical characteristics and infectious causes of diarrhea among migrant workers in Doha, Qatar. A total of 126 male workers presenting to the Qatar Red Crescent Worker's Health Center outpatient clinic or emergency department were studied over a 5-month period in 2015–2016. Epidemiologic surveys were administered to all subjects and the prevalence of 22 different stool pathogens was determined using multiplex polymerase chain reaction (PCR) (FilmArray^® Gastrointestinal PCR). A target pathogen was identified in 62.7% of subjects. Enteropathogenic Escherichia coli was the most prevalent pathogen and was detected in 24.6% of subjects, followed by Salmonella (22.2%), enteroaggregative E. coli (15.1%), Giardia lamblia (9.5%), and enterotoxigenic E. coli (8.7%). Multiple pathogens were identified in 49.3% of positive stool samples. In a multivariable analysis, the presence of a heart rate ≥ 90 (adjusted odds ratio [OR] = 3.7, 95% confidence interval [CI] = 1.4–10.0) and > 5 fecal leukocytes/high-power field (adjusted OR = 2.8, 95% CI = 1.2–7.0) were significant predictors of detecting an acute inflammatory pathogen by PCR. Use of multiplex PCR enabled the detection of gastrointestinal pathogens in a high proportion of cases, illustrating the utility of this diagnostic tool in epidemiologic studies of infectious diarrhea.

Salmonella Serogroup C: Current Status of Vaccines and Why They Are Needed

Nontyphoidal Salmonella (NTS; i.e., Salmonella enterica organisms that do not cause typhoid or paratyphoid) are responsible for 94 million infections and 155,000 deaths worldwide annually, 86% of which are estimated to be foodborne. Although more than 50 serogroups and 2,600 serovars have been described, not all Salmonella serovars cause disease in humans and animals. Efforts are being made to develop NTS vaccines, with most approaches eliciting protection against serovars Typhimurium and Enteritidis (serogroups B [O:4] and D [O:9], respectively), as they are widely considered the most prevalent. Here, we show that serogroup C (O:6,7, O:6,8, or O:8 epitopes) is the most common serogroup in the United States, and the prevalence of serovars from this serogroup has been increasing in Europe and the United States over the last decade. They are also the most commonly isolated serovars from healthy cattle and poultry, indicating the underlying importance of surveillance in animals. Four out of the 10 most lethal serovars in the United States are serogroup C, and reports from African countries suggest that strains within this serogroup are highly antibiotic resistant. Serogroup C consists of highly diverse organisms among which 37 serovars account for the majority of human cases, compared to 17 and 11 serovars for serogroups B and D, respectively. Despite these concerning data, no human vaccines targeting serogroup C NTS are available, and animal vaccines are in limited use. Here, we describe the underestimated burden represented by serogroup C NTS, as well as a discussion of vaccines that target these pathogens.

Foodborne Bacterial Pathogens Associated with the Risk of Gastroenteritis in the State of Qatar

OBJECTIVE

To assess the risk of gastroenteritis associated with bacterial foodborne pathogens and identify associated factors in a highly diverse population.

MATERIAL AND METHODS

A series of case-control studies were carried out to address the stated objective. The study population consisted of individuals who were admitted to the Hamad Medical Corporation hospitals and stool analysis indicated positive findings to Campylobacter spp., Escherichia coli, or Salmonella spp. between the period of August 2009 and December 2012. Cases were defined based on positive stool analysis to any of the previously mentioned organisms. Control group was similar to case group but negative in stool analysis to the particular pathogen under study. Association between demographic characteristics and likelihood of pathogen infection were investigated using logistic regression analysis.

RESULTS

A total of 423 individuals diagnosed with these bacterial pathogens were randomly enrolled in the study. The majority of cases were infected by E.coli. Age was significantly associated with E.coli and Salmonella spp.

CONCLUSION

E.coli infection is common among young children. The risk of Salmonella increases with age. Campylobacter may affect any age. Further investigation of interaction between foodborne pathogen infection and environmental factors is necessary.

Retinoic acid decreases the severity of Salmonella enterica serovar Typhimurium mediated gastroenteritis in a mouse model

Gastroenteritis is a global burden; it's the major cause of morbidity and mortality both in adults and children of developing countries. Salmonella is one of the leading causes of bacteria-mediated gastroenteritis and due to its increasing multidrug antibiotic resistance; Salmonella-mediated gastroenteritis is difficult to control. Retinoic acid, the biologically active agent of vitamin A has an anti-inflammatory effect on experimental colitis. In this study we have shown All trans retinoic acid (ATRA) treatment down regulates Salmonella-mediated colitis in a murine model. Macroscopic signs of inflammation such as decrease in body weight and cecum weight, shorter length of proximal colon and pathological score of colitis were observed less in ATRA treated mice than in a vehicle control group. ATRA treatment not only reduced pro-inflammatory cytokine responses, such as TNF-α, IL-6, IL-1β, IFN-γ and IL-17 production but also increased IL-10 response in the supernatant of intestinal tissue. Results also suggested that ATRA treatment enhances the number of FoxP3-expressing T regulatory cells in MLN and also decreases bacterial load in systemic organs. We concluded that ATRA treatment indeed reduces Salmonella Typhimurium-mediated gastroenteritis in mice, suggesting it could be an important part of an alternative therapeutic approach to combat the disease.

Sequence and phylogenetic analysis of H2N7 avian influenza viruses isolated from domestic ducks in Zhejiang Province, Eastern China, 2013

Two H2N7 avian influenza viruses (AIVs) were isolated from domestic ducks in live poultry markets in Zhejiang Province, Eastern China, 2013. All viruses were characterized by whole-genome sequencing with subsequent phylogenetic analysis and genetic comparison. Phylogenetic analysis of all eight viral genes showed that the viruses clustered in the Eurasian lineage of AIVs and originated from genes reassortment among different viruses co-circulating in domestic ducks in Eastern China. The hemagglutinin cleavage site of all viruses indicated that the two strains were low-pathogenic avian influenza viruses. Considering the important role of the domestic ducks in the dissemination and reassortment of AIVs, continued surveillance of circulating H2 subtype AIVs in domestic ducks in live poultry markets is needed.