Genetic characterisation of multidrug-resistant Salmonella enterica serotypes isolated from poultry in Cairo, Egypt

Salmonella Prevalence and antibiotic resistance profile in raw poultry meat sold in North Lebanon: Insights from the COVID-19 pandemic and economic crisis

Salmonella-related foodborne illness is a significant public health concern, with the primary source of human infection being animal-based food products, particularly chicken meat. Lebanon is currently experiencing a dual crisis: the COVID-19 pandemic and an unprecedented economic crisis, which has resulted in substantial challenges to the public health system and food safety. This study aims to assess the prevalence and antibiotic resistance profile of Salmonella in raw poultry meat sold in North Lebanon during this dual crisis. A cross-sectional study was carried out between May 2021 and April 2022 across six different districts in North Lebanon. A total of 288 whole, unprocessed chickens were examined. The isolation and identification of Salmonella isolates were done based on cultural and biochemical properties. All isolates were subjected to antimicrobial susceptibility testing and phenotypic assays for Extended-Spectrum Beta-lactamase (ESBL) detection. The prevalence of Salmonella in raw poultry meat purchased in North Lebanon reached 18.05 % (52/288). The dry season and chilled chicken were significantly associated with an increased risk of Salmonella contamination (P < 0.05). Additionally, 34.61 % of the isolates were potential ESBL producers, and 57.69 % exhibited multidrug resistance (MDR). This study highlights the existence of MDR in chicken meat in North Lebanon, posing a potential health risk if undercooked chicken meat is consumed. This emphasizes the importance of the implementation of preventive strategies and hygienic procedures throughout the food chain to reduce the risk of Salmonella spp. contamination in chicken meats and its potential transmission to humans.

Food safety control in poultry industry: prevalence and antimicrobial susceptibility of Escherichia coli isolated from raw chicken and the potential use of Origanum essential oils as alternative to antibiotics

1. The extensive use of antimicrobials in poultry production may contribute to the emergence of resistant bacteria. This study was conducted to determine the prevalence and resistance of different E. coli strains isolated from raw chicken meat and to investigate the possibility to use Lebanese native oregano essential oils as alternatives.2. In total, 250 chickens from Lebanese markets were examined for the presence of E. coli. Isolates were then screened for susceptibility using 19 antibiotics and two essential oils extracted from oregano plants.3. Of the 250 chickens tested, 80% were contaminated with E. coli. Main resistance was seen against amoxycillin, ampicillin, penicillin, tetracycline, tylosin, streptomycin and erythromycin. The highest rate of sensitivity was found in 86.1% of strains to Amoxycillin/Clavulanic acid, 80.09% to Tilmicosin. Both essential oils from Origanum syriacum (98%) and O. ehrenbergii (97.3%) showed promising potential in inhibiting the growth of the tested bacteria. Oil from O. syriacum exhibited superior efficacy against 200 E. coli strains, inhibiting 46.1% at 200 mg/l and all at 400 mg/l, while O. ehrenbergii oil showed slightly lower inhibition, affecting 41.6% at 200 mg/l and all at 400 mg/l.

Synanthropic rodents and shrews are reservoirs of zoonotic bacterial pathogens and act as sentinels for antimicrobial resistance spillover in the environment: A study from Puducherry, India

Antimicrobial resistance (AMR) is a global public health concern and needs to be monitored for control. In this study, synanthropic rodents trapped from humans and animal habitats in Puducherry, India, were screened as sentinels for bacterial pathogens of public health importance and antimicrobial resistance spillover. From the trapped rodents and shrews (n = 100) pathogens viz., Staphylococcus sp, E. coli and Salmonella sp were isolated from oropharyngeal and rectal swabs on Mannitol salt, Mac Conkey and Xylose lysine deoxycholate media respectively. The AMR genes in these isolates were screened by PCR. A total of 76, S. aureus and 19, Staphylococcus non aureus were isolated. E. coli was isolated in 89 samples and among the Salmonella sp (n = 59), 16, were S. enteritidis and 29, were S. typhimurium. A total of 46 MRSA isolates with mec A (n = 40) and mec C (n = 6) were detected. Also, 36.84% and 5.3% Staphylococcus non aureus isolates were tested to have mec A and mec C genes. AMR genes encoding ESBL [blaTEM in 21, blaSHV in 45 and blaCTX-M in 11] was tested positive in 77 E. coli isolates. Among, Salmonella isolates 44/45 were screened to have AMR genes [tet in 13, sul3 & sul4 in 20 and qnrA in 11]. Antibiotic sensitivity test confirmed the antimicrobial resistance. Isolation of pathogens of public health importance and demonstration of genetic elements conferring antimicrobial resistance in the synanthropic rodents confirms that they act as reservoirs and appropriate sentinels to monitor AMR spillover in the environment.

Prevalence and antimicrobial susceptibility of Salmonella enteritidis and Salmonella typhimurium isolated from hen eggs and quail eggs in Karaj, Iran

BACKGROUND AND AIM

Different Salmonella serotypes are considered one of the most important food pathogens in the world. Poultry meat and eggs are the primary carriers of Salmonella in human populations. This study aimed to estimate the Salmonella enteritidis and Salmonella typhimurium contamination rates of retail hen and quail eggs in Karaj, Iran. Moreover, the antimicrobial resistance patterns of the strains were evaluated, and the efficiency of the standard culture method and multiplex polymerase chain reaction (m-PCR) were compared.

MATERIALS AND METHODS

In this descriptive cross-sectional study over 1 year (Jan-Dec 2022), 150 commercial and 150 backyard hen eggs and 300 commercial quail eggs, without cracks and fractures, were collected randomly from best selling groceries in Karaj city. All samples were examined for Salmonella contamination independently by standard culture and m-PCR approaches. A standard disc diffusion method was employed to assess the antimicrobial susceptibility of the strains against 18 antimicrobial agents.

RESULTS

Out of 300 examined eggs, 2 S. enteritidis strains were isolated from the shell of backyard hen eggs. The same serotype was also detected in the contents of one of these two eggs. One S. typhimurium was isolated from the shell of a commercial hen egg. Overall, the Salmonella contamination of the shell and contents was 1% and 0.3%, respectively. Salmonella was not isolated from the eggshells or the contents of the quail eggs. There was complete agreement between the results of m-PCR and the standard culture methods. Among the 18 tested antibiotics, the highest resistance was recorded for colistin (100%), followed by nalidixic acid (75%).

CONCLUSION

As most Salmonella spp. are associated with human food poisoning, continuous surveillance is required to effectively reduce the risk posed by contaminated poultry eggs. Furthermore, mandatory monitoring of antimicrobial use on Iranian poultry farms is recommended.

Application of a novel lytic Jerseyvirus phage LPSent1 for the biological control of the multidrug-resistant Salmonella Enteritidis in foods

Non-typhoidal Salmonella is the tremendously predominant source of acquired foodborne infection in humans, causing salmonellosis which is a global threat to the healthcare system. This threat is even worse when it is combined with the incidence of multidrug-resistant Salmonella strains. Bacteriophage therapy has been proposed as a promising potential candidate to control a diversity of foodborne infective bacteria. The objective of this study designed to isolate and characterize lytic phages infecting zoonotic multi-drug resistant and strong biofilm producer Salmonella enterica serovar Enteritidis EG.SmE1 and then apply the isolated phage/s as a biocontrol agent against infections in ready-to-eat food articles including milk, water, apple juice, and chicken breasts. One lytic phage (LPSent1) was selected based on its robust and stable lytic activity. Phage LPSent1 belonged to the genus Jerseyvirus within the Jerseyvirinae subfamily. The lysis time of phage LPSent1 was 60 min with a latent period of 30 min and each infected cell burst about 112 plaque-forming units. Phage LPSent1 showed a narrow host range. Furthermore, the LPSent1 genome did not encode any virulence or lysogenic genes. In addition, phage LPSent1 had wide pH tolerance, prolonged thermal stability, and was stable in food articles lacking its susceptible host for 48 h. In vitro applications of phage LPSent1 inhibited free planktonic cells and biofilms of Salmonella Enteritidis EG.SmE1 with a lower occurrence to form phage-resistant bacterial mutants which suggests promising applications on food articles. Application of phage LPSent1 at multiplicities of infections of 100 or 1000 showed significant inhibition in the bacterial count of Salmonella Enteritidis EG.SmE1 by 5 log10/sample in milk, water, apple juice, and chicken breasts at either 4°C or 25°C. Accordingly, taken together these findings establish phage LPSent1 as an effective, promising candidate for the biocontrol of MDR Salmonella Enteritidis in ready-to-eat food.

A Public Health Insight into Salmonella in Poultry in Africa: A Review of the Past Decade: 2010-2020

Poultry is a cheap source of animal protein and constituent of diets in Africa. Poultry can serve as a reservoir for Salmonella and cause food-borne infections in humans. This review describes Salmonella contamination of food, poultry, and the farming environment, antimicrobial resistance profiles, and serotypes of Salmonella, as well as the farming systems, antimicrobial use (AMU), hygiene, and husbandry conditions used to rear poultry in Africa. Using the PRISMA (preferred reporting items for systematic reviews and meta-analysis) guidelines, PubMed, Science Direct, and Web of Science databases were searched using a set of predefined keywords. Full-length research articles in English were examined for the period 2010-2020 and relevant information extracted for the narrative synthesis. Of the articles that met the inclusion criteria, 63.1% were conducted on farms and among households, while 36.9% were undertaken at government-controlled laboratories, which quarantine imported birds, processing plants, and retail outlets. The farming systems were intensive, semi-intensive, and extensive. AMU was described in 11.5% of the studies and varied within and across countries. Multidrug-resistant (MDR) Salmonella isolates were detected in 30 studies and the prevalence ranged from 12.1% in Zimbabwe to 100% in Egypt, Ethiopia, Nigeria, Senegal, and South Africa. A total of 226 different Salmonella serotypes were reported. Twenty-four (19.7%) of the studies reported food-borne Salmonella contamination in eggs, poultry, and poultry products at retail outlets and processing plants. The apparent extensive use of antimicrobials and circulation of MDR Salmonella isolates of various serotypes in Africa is a concern. It is important to implement stricter biosecurity measures on farms, regulate the use of antimicrobials and implement surveillance systems, in addition to food safety measures to monitor the quality of poultry and poultry products for human consumption.

Antimicrobial resistance and virulence genes in Salmonella enterica serovars isolated from droppings of layer chicken in two farms in Nigeria

AIM

This study aimed to investigate the isolation rate, antibiotic resistance, and virulence genes of Salmonella enterica serovar from two commercial farms in Nigeria.

METHODS AND RESULTS

Salmonella isolation was performed according to the United States Food and Drug Agency (USFDA) method. Serotyping, antimicrobial susceptibility testing, detection of resistance and virulence genes were done using the Kauffman-White Scheme, disc diffusion, minimum inhibitory concentration, and real-time polymerase chain reaction techniques. Salmonella serovars were isolated from only farm A at 22/50 (44.0%) while none were isolated from farm B. Salmonella Typhi, 9 (40.9%); Salmonella Typhimurium, 2 (9.1%), Salmonella Enteritidis, 2 (9.1%), Salmonella Pullorum, 1 (4.5%), Salmonella Kentucky, 4 (18.2%) were identified while 4 (18.2%) were untypable. Sixteen isolates (72.7%) showed multiple drug resistance and 17 different resistance profile types with AMP-CHL-TRM-SXT as the most prevalent pattern. Resistance genes (blaTEM, 12/22 (54.5%) and virulence genes (InvA, sopB, mgtC, and spi4D, 22/22 (100.0%), ssaQ, 16/22 (72.7%), and spvC, 13/22 (59.1%) were found, while blaSHV, blaCTX-M, floR, tetA, tetB, tetG, and LJSGI-1 genes were absent.

CONCLUSION

Pathogenic Salmonella were isolated from the chicken droppings in this study. Most of these strains were resistant to antibiotics and possessed characteristics of virulence.

SIGNIFICANCE AND IMPACT OF THE STUDY

Chicken droppings from this study area contained pathogenic strains of Salmonella and a rare occurrence of Salmonella Typhi. The study revealed that the environment and the food chain could be at risk of contamination of highly virulent and antimicrobial-resistant strains of Salmonella. These could affect the profitability of the poultry industry and food consumption. There is a need for caution in indiscriminate disposal of poultry waste and the use of uncomposted chicken droppings in soil amendment.

Current State of Salmonella, Campylobacter and Listeria in the Food Chain across the Arab Countries: A Descriptive Review

Foodborne infections caused by bacterial pathogens are a common cause of human illness in the Middle East, with a substantial burden of economic loss and public health consequences. This review aims at elucidating recent literature on the prevalence of Non-Typhoidal Salmonella (NTS), Campylobacter and Listeria monocytogens in the food chain in the Arab countries, and to consolidate available evidence on the public health burden and the status of antimicrobial resistance (AMR) among the concerned three pathogens. The reviewed evidence points to a scarcity of understanding of the magnitude of NTS in the food chain in the Arab countries. Additionally, not much work has been done at the molecular characterization level to address the source-attribution of NTS in the Arab World. Very few surveys have been done on Campylobacter in the food chain in the Gulf Cooperation Council (GCC) countries. There is a gap in quantitative (counts/numbers) surveillance efforts for Campylobacter in the chicken meat supply across all Arab countries, despite the availability of some qualitative (presence/absence) surveillance data. While there are several reports on L. monocytogenes in animal-sourced foods, notably in North African Arab countries, fewer are published on L. monocytogenes in plant-sourced foods. Information on the L. monocytogenes serotypes and strain diversity circulating in the Arab region is widely lacking. Antibiotic resistance in the three pathogens is not fully understood across the Arab region, despite some reports indicating varying trends at the human-food interface. The literature evidence presented in this review stresses that Salmonella, Campylobacter and L. monocytogenes continue to challenge food safety and public health in the Arab countries.

Prevalence, virulence factor and antimicrobial resistance analysis of Salmonella Enteritidis from poultry and egg samples in Iran

BACKGROUND

Salmonella enterica serovar Enteritidis (S. Enteritidis) is one of the most common serovars, associated with human salmonellosis. The food-borne outbreak of this bacterium is mainly related to the consumption of contaminated poultry meat and poultry products, including eggs. Therefore, rapid and accurate detection, besides investigation of virulence characteristics and antimicrobial resistance profiles of S. Enteritidis in poultry and poultry egg samples is essential. A total of 3125 samples (2250 poultry and 875 poultry egg samples), sent to the administrative centers of veterinary microbiology laboratories in six provinces of Iran, were examined for Salmonella contamination, according to the ISO 6579 guideline. Next, duplex PCR was conducted on 250 presumptive Salmonella isolates to detect invA gene for identification of the genus Salmonella and sdf gene for identification of S. Enteritidis. Subsequently, the S. Enteritidis isolates were examined for detection of important virulence genes (pagC, cdtB, msgA, spaN, tolC, lpfC, and spvC) and determination of antibiotic resistance patterns against nalidixic acid, trimethoprim-sulfamethoxazole, cephalothin, ceftazidime, colistin sulfate, and kanamycin by the disk diffusion method.

RESULTS

Overall, 8.7 and 2.3% of poultry samples and 6.3 and 1.3% of eggs were contaminated with Salmonella species and S. Enteritidis, respectively. The invA and msgA genes (100%) and cdtB gene (6.3%) had the highest and the lowest prevalence rates in S. Enteritidis isolates. The spvC gene, which is mainly located on the Salmonella virulence plasmid, was detected in 50.8% of S. Enteritidis isolates. The S. Enteritidis isolates showed the highest and the lowest resistance to nalidixic acid (87.3%) and ceftazidime (11.1%), respectively. Unfortunately, 27.0% of S. Enteritidis isolates were multidrug-resistant (MDR).

CONCLUSION

The rate of contamination with Salmonella in the poultry and egg samples, besides the presence of antimicrobial resistant and MDR Salmonella isolates harboring the virulence genes in these samples, could significantly affect food safety and subsequently, human health. Therefore, continuous monitoring of animal-source foods, enhancement of poultry farm control measures, and limiting the use of antibiotics for prophylactic purposes in food producing animals, are essential for reducing the zoonotic risk of this foodborne pathogen for consumers and also choosing effective antibiotics for the treatment of salmonellosis.

Isolation and Characterization of Two Lytic Bacteriophages Infecting a Multi-Drug Resistant Salmonella Typhimurium and Their Efficacy to Combat Salmonellosis in Ready-to-Use Foods

Foodborne salmonellosis is a global threat to public health. In the current study, we describe the isolation and characterization of two broad-spectrum, lytic Salmonella phages: SPHG1 and SPHG3 infecting a multidrug-resistant Salmonella Typhimurium EG.SmT3. Electron microscopy and whole genome analysis identified SPHG1 as a Myovirus, while SPHG3 as a new member of the genus "Kuttervirus" within the family Ackermannviridae. SPHG1 and SPHG3 had a lysis time of 60 min. with burst sizes of 104 and 138 PFU/cell, respectively. The two phages were robust at variable temperatures and pH ranges that match the corresponding values of most of the food storage and processing conditions. A phage cocktail containing the two phages was stable in the tested food articles for up to 48 h. The application of the phage cocktail at MOIs of 1000 or 100 resulted in a significant reduction in the viable count of S. Typhimurium by 4.2 log10/sample in milk, water, and on chicken breast. Additionally, the phage cocktail showed a prospective ability to eradicate and reduce the biofilm that formed by S. Typhimurium EG.SmT3. A phage cocktail of SPHG1 and SPHG3 is considered as a promising candidate as a biocontrol agent against foodborne salmonellosis due to its broad host ranges, highly lytic activities, and the absence of any virulence or lysogeny-related genes in their genomes.

Shared Extended-Spectrum β-Lactamase-Producing Salmonella Serovars between Agricultural and Aquatic Environments Revealed through invA Amplicon Sequencing

The presence of antibiotic-resistant Salmonella spp. in the environment is of great public health interest, worldwide. Furthermore, its extended-spectrum β-lactamase (ESBL)-producing strains constitute an emerging global health concern due to their limited treatment options in hospital. Therefore, this study aimed at characterising and tracking nonresistant and ESBL-producing Salmonella spp. from agricultural settings to nearby water sources highlighting their antibiotic resistance genes (ARG) and virulence factor (VF) distribution using a combination of both culture-dependent and independent methods. Furthermore, this study investigated the diversity and shared serovars among sampled matrices using amplicon sequencing of the invasion gene A (invA) of Salmonella spp. The results showed that soil had the highest prevalence of Salmonella spp. (62.5%, 65/104) and ESBL-producing Salmonella (34.6%, 36/104). For typed ARG, the most commonly detected gene was blaOXA with 75% (30/40), followed by blaCTX-M 67.5% (27/40),blaTEM 40% (16/40) and sul1 30% (12/40) gene; blaSHV gene was not detected in isolated ESBL-producing Salmonella spp. For VF, the most detected gene was invA (96.9%, 38/40), followed by spaM (17.5%, 7/40), spiC (40%, 16/40), orfL (32.5%, 13/40), misL 32.5% (13/40) and pipD 32.5 (13/40). For diversity analysis, soil, manure, irrigation water and nearby freshwater revealed 81, 68, 12 and 9 serovars, respectively. Soil, manure, irrigation water and freshwater stream samples shared five serovars, which indicated circulation of ESBL-producing Salmonella spp. within the agricultural environment and nearby water sources. Soil is therefore identified as one of the major reservoirs of ESBL-producing Salmonella spp. It is concluded that agricultural environment contamination may have a direct relationship with the presence of antibiotic-producing Salmonella in freshwater streams.

Antibiogram Profiles and Risk Factors for Multidrug Resistance of Salmonella enterica Recovered from Village Chickens (Gallus gallus domesticus Linnaeus) and Other Environmental Sources in the Central and Southern Peninsular Malaysia

The emergence of multidrug resistance (MDR), including colistin resistance, among Enterobacteriaceae recovered from food animals poses a serious public health threat because of the potential transmission of these resistant variants to humans along the food chain. Village chickens or Ayam Kampung are free-range birds and are preferred by a growing number of consumers who consider these chickens to be organic and more wholesome. The current study investigates the antibiogram profiles of Salmonella isolates recovered from village chicken flocks in South-central Peninsular Malaysia. A total of 34 isolates belonging to eight serotypes isolated from village chickens were screened for resistance towards antimicrobials including colistin according to the WHO and OIE recommendations of critical antibiotics. S. Weltevreden accounted for 20.6% of total isolates, followed by serovars Typhimurium and Agona (17.6%). The majority of isolates (73.5%) demonstrated resistance to one or more antimicrobials. Eight isolates (23.5%) were resistant to ≥3 antimicrobial classes. Colistin resistance (minimum inhibitory concentrations: 4-16 mg/L) was detected among five isolates (14.7%), including S. Weltevreden, S. Albany, S. Typhimurium, and Salmonella spp. Univariable analysis of risk factors likely to influence the occurrence of MDR Salmonella revealed that the flock size, poultry production system, and use of antibiotics in the farm were not significantly (p > 0.05) associated with MDR Salmonella. The current study highlights that MDR Salmonella occur at a lower level in village chickens compared to that found in live commercial chickens. However, MDR remains a problem even among free-range chickens with minimal exposure to antibiotics.

Antibiotic resistance in Salmonella spp. isolated from poultry: A global overview

Salmonella enterica is the most important foodborne pathogen, and it is often associated with the contamination of poultry products. Annually, Salmonella causes around 93 million cases of gastroenteritis and 155,000 deaths worldwide. Antimicrobial therapy is the first choice of treatment for this bacterial infection; however, antimicrobial resistance has become a problem due to the misuse of antibiotics both in human medicine and animal production. It has been predicted that by 2050, antibiotic-resistant pathogens will cause around 10 million deaths worldwide, and the WHO has suggested the need to usher in the post-antibiotic era. The purpose of this review is to discuss and update the status of Salmonella antibiotic resistance, in particular, its prevalence, serotypes, and antibiotic resistance patterns in response to critical antimicrobials used in human medicine and the poultry industry. Based on our review, the median prevalence values of Salmonella in broiler chickens, raw chicken meat, and in eggs and egg-laying hens were 40.5% ( interquartile range [IQR] 11.5-58.2%), 30% (IQR 20-43.5%), and 40% (IQR 14.2-51.5%), respectively. The most common serotype was Salmonella Enteritidis, followed by Salmonella Typhimurium. The highest antibiotic resistance levels within the poultry production chain were found for nalidixic acid and ampicillin. These findings highlight the need for government entities, poultry researchers, and producers to find ways to reduce the impact of antibiotic use in poultry, focusing especially on active surveillance and finding alternatives to antibiotics.

Phenotypes, antibacterial-resistant profile, and virulence-associated genes of Salmonella serovars isolated from retail chicken meat in Egypt

AIM

The present study was designed to investigate the occurrence and distribution of Salmonella serotypes in chicken meat samples, and to explore the susceptibility of the strains to antimicrobials, as well as their virulence-associated genes.

MATERIALS AND METHODS

Two-hundred retail chicken meat samples from different shops, as well as 25 stool specimens from retail shop workers, were included in the study. The collected samples were examined bacteriologically for the presence of salmonellae. Salmonella isolates were serotyped using a slide agglutination test for O and H antigens and were screened for the presence of five virulence genes (stn, pef, inv A , sop B , and avrA) using a uniplex polymerase chain reaction assay and for their susceptibility to 18 antimicrobial agents using the disk diffusion method.

RESULTS

Thirty-one Salmonella isolates belonging to 12 different serovars were identified. Salmonella Enteritidis and Salmonella Kentucky were the dominant serovars (22.6% each). Salmonella isolates displayed a high antibiotic resistance against erythromycin, sulfamethoxazole/trimethoprim, doxycycline, cephalexin, cefaclor, tetracycline, polymyxin B, cefuroxime, vancomycin, and streptomycin. All Salmonella isolates exhibited multidrug resistance (MDR) and demonstrated different virulence genes. The majority of Salmonella serovars (87.1%) harbored sopB gene, 54.8% carried avrA and pef genes, while all isolates carried invA and stn genes.

CONCLUSION

The presence of virulent MDR Salmonellae in raw chicken meat could allow the possibility of transmission of these resistant serovars to humans. Therefore, strict hygienic measures should be followed on the whole poultry production chain to decrease the potential transmission of Salmonella infection from poultry meat to humans.

Prevalence of Campylobacter and Salmonella in African food animals and meat: A systematic review and meta-analysis

BACKGROUND

Campylobacter and Salmonella, particularly non-typhoidal Salmonella, are important bacterial enteric pathogens of humans which are often carried asymptomatically in animal reservoirs. Bacterial foodborne infections, including those derived from meat, are associated with illness and death globally but the burden is disproportionately high in Africa. Commercial meat production is increasing and intensifying in many African countries, creating opportunities and threats for food safety.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, we searched six databases for English language studies published through June 2016, that reported Campylobacter or Salmonella carriage or infection prevalence in food animals and contamination prevalence in food animal products from African countries. A random effects meta-analysis and multivariable logistic regression were used to estimate the species-specific prevalence of Salmonella and Campylobacter and assess relationships between sample type and region and the detection or isolation of either pathogen.

RESULTS

Seventy-three studies reporting Campylobacter and 187 studies reporting Salmonella across 27 African countries were represented. Adjusted prevalence calculations estimate Campylobacter detection in 37.7% (95% CI 31.6-44.3) of 11,828 poultry samples; 24.6% (95% CI 18.0-32.7) of 1975 pig samples; 17.8% (95% CI 12.6-24.5) of 2907 goat samples; 12.6% (95% CI 8.4-18.5) of 2382 sheep samples; and 12.3% (95% CI 9.5-15.8) of 6545 cattle samples. Salmonella were detected in 13.9% (95% CI 11.7-16.4) of 25,430 poultry samples; 13.1% (95% CI 9.3-18.3) of 5467 pig samples; 9.3% (95% CI 7.2-12.1) of 2988 camel samples; 5.3% (95% CI 4.0-6.8) of 72,292 cattle samples; 4.8% (95% CI 3.6-6.3) of 11,335 sheep samples; and 3.4% (95% CI 2.2-5.2) of 4904 goat samples. 'External' samples (e.g. hide, feathers) were significantly more likely to be contaminated by both pathogens than 'gut' (e.g. faeces, cloaca) while meat and organs were significantly less likely to be contaminated than gut samples.

CONCLUSIONS

This study demonstrated widespread prevalence of Campylobacter species and Salmonella serovars in African food animals and meat, particularly in samples of poultry and pig origin. Source attribution studies could help ascertain which food animals are contributing to human campylobacteriosis and salmonellosis and direct potential food safety interventions.

Diversity and Antimicrobial Resistance Genotypes in Non-Typhoidal Salmonella Isolates from Poultry Farms in Uganda

Non-typhoidal Salmonella (NTS) are foodborne pathogens of global public health significance. The aim of this study was to subtype a collection of 85 NTS originating from poultry farms in Uganda, and to evaluate a subgroup of phenotypically resistant isolates for common antimicrobial resistance genes and associated integrons. All isolates were subtyped by pulsed-field gel electrophoresis (PFGE). Phenotypically resistant isolates (n = 54) were screened by PCR for the most relevant AMR genes corresponding to their phenotypic resistance pattern, and all 54 isolates were screened by PCR for the presence of integron class 1 and 2 encoding genes. These genes are known to commonly encode resistance to ampicillin, tetracycline, ciprofloxacin, trimethoprim, sulfonamide and chloramphenicol. PFGE revealed 15 pulsotypes representing 11 serotypes from 75 isolates, as 10 were non-typable. Thirty one (57.4%) of the 54 resistant isolates carried at least one of the seven genes (blaTEM-1,cmlA, tetA, qnrS,sul1,dhfrI,dhfrVII) identified by PCR and six (11%) carried class 1 integrons. This study has shown that a diversity of NTS-clones are present in Ugandan poultry farm settings, while at the same time similar NTS-clones occur in different farms and areas. The presence of resistance genes to important antimicrobials used in human and veterinary medicine has been demonstrated, hence the need to strengthen strategies to combat antimicrobial resistance at all levels.

Prevalence, antimicrobial susceptibility and risk factors associated with non-typhoidal Salmonella on Ugandan layer hen farms

BACKGROUND

Non-typhoidal Salmonella (NTS) are among the leading global foodborne pathogens and a significant public health threat. Their occurrence in animal reservoirs and their susceptibilities to commonly used antimicrobials are poorly understood in developing countries. The aim of this study was to estimate the prevalence, determine antimicrobial susceptibility and identify risk factors associated with NTS presence in laying hen farms in Uganda through a cross-sectional study.

RESULTS

Pooled faecal samples were collected from 237 laying hen farms and these were analysed for NTS following standard laboratory procedures. In total, 49 farms (20.7%; 95% Confidence interval (CI): 15.6-25.6%) were positive for NTS presence. Altogether, ten Salmonella serotypes were identified among the confirmed 78 isolates, and the predominant serotypes were Salmonella Newport (30.8%), S. Hadar (14.1%), S. Aberdeen (12.8%), S. Heidelberg (12.8%), and S. Bolton (12.8%). Phenotypic antimicrobial resistance was detected in 45(57.7%) of the isolates and the highest resistance was against ciprofloxacin (50.0%) followed by sulphonamides (26.9%) and sulphamethoxazole/trimethoprim (7.7%). Resistance was significantly associated with sampled districts (p = 0.034). Resistance to three or more drugs, multi-drug resistance (MDR) was detected in 12 (15.4%) of the isolates, 9 (75%) of these were from Wakiso district. A multivariable logistic model identified large farm size (OR = 7.0; 95% CI: 2.5-19.8) and the presence of other animal species on the farm (OR = 5.9; 95% CI: 2.1-16.1) as risk factors for NTS prevalence on farms. Having a separate house for birds newly brought to the farms was found to be protective (OR = 0,4; 95% CI: 0.2-0.8).

CONCLUSION

This study has highlighted a high prevalence and diversity of NTS species in laying hen farms in Uganda and identified associated risk factors. In addition, it has demonstrated high levels of antimicrobial resistance in isolates of NTS. This could be because of overuse or misuse of antimicrobials in poultry production. Also importantly, the insights provided in this study justifies a strong case for strengthening One Health practices and this will contribute to the development of NTS control strategies at local, national and international levels.

Characterization of Salmonella Gallinarum from an outbreak in Raigarh, Chhattisgarh

AIM

The present investigation was conducted to isolate and characterize Salmonella Gallinarum from an outbreak of fowl typhoid in layer birds.

MATERIALS AND METHODS

Clinically ill and dead layer birds from an outbreak were investigated. History, clinical signs, and postmortem lesions were suggestive of fowl typhoid. Postmortem samples including heart blood, intestinal contents, pieces of ovary, and liver were collected and processed immediately for bacterial culture, serotyping and antibiotic sensitivity tests. Isolates were further screened for the presence of extended spectrum beta lactamase (ESBL) (blaTEM) gene by polymerase chain reaction.

RESULTS

On the basis of cultural, staining and biochemical characteristics; three bacterial isolates were confirmed as S. Gallinarum. On serotyping, somatic antigen O: 9 and 12 with nonflagellated antigen were detected in all three isolates. Isolates were intermediate sensitive to amoxycillin, amoxyclav, gentamicin and ciprofloxacin and resistant to most of the antibiotics including chloramphenicol, ampicillin, ceftazidime, cefexime, cefepime, azithromycin, nalidixin, tetracycline, oxytetracycline, and streptomycin. Two isolates were found to harbor ESBL (blaTEM) gene.

CONCLUSION

Beta lactamase producer S. Gallinarum was confirmed as cause of increased mortality in layer birds during present investigation. Existence of multi drug resistant Salmonella poses serious threat to poultry industry in Chhattisgarh.

Abusive use of antibiotics in poultry farming in Cameroon and the public health implications

The types and methods of use of antibiotics in poultry farms in Cameroon, residual levels and potential microbial resistance were determined. A questionnaire-based survey identified the different antibiotics used and high-performance liquid chromatography (HPLC) was used to determine residual levels of antibiotics. Pathogens were isolated, identified by use of commercial API kits and minimum inhibition concentration (MIC) was determined. Oxytetracyclin, tylocip and TCN (oxytetracycline, chloramphenicol and neomycin) were the most frequently used antibiotics. Antibiotics screened by HPLC were chloramphenicol, tetracycline and vancomycin. All of them except vancomycin were detected, and the concentration of these antibiotics was higher than the maximum residual limits (MRL) set by regulatory authorities. No residues of various antibiotics were found in egg albumen or yolk. The concentration of tetracycline was significantly higher in liver (150 ± 30 µg/g) than in other tissues. Foodborne pathogens, including Salmonella spp., Staphylococcus spp., Listeria spp., Clostridium spp. and Escherichia spp., were identified. Most of the pathogens were resistant to these various antibiotics tested. These findings imply the need for better management of antibiotic use to control sources of food contamination and reduce health risks associated with the presence of residues and the development of resistant pathogens by further legislation and enforcement of regulations on food hygiene and use of antibiotics.