Prevalence and Antibiotic Resistance of Salmonella Isolated from a Poultry Farm and Processing Plant Environment in the State of Kuwait

Prevalence of multi-antimicrobial resistant non-typhoidal Salmonella isolated from filth flies at wet markets in Klang, Malaysia, and their survival in the simulated gastric fluid

Filth flies at wet markets can be a vector harbouring multiple antimicrobial-resistant (MAR) nontyphoidal Salmonella (NTS), and such strains are a significant threat to public health as they may cause severe infections in humans. This study aims to investigate the prevalence of antimicrobial-resistant NTS, especially Salmonella Enteritidis and S. Typhimurium harboured by filth flies at wet markets, and investigate their survival in the simulated gastric fluid (SGF). Filth flies (n = 90) were captured from wet markets in Klang, Malaysia, and processed to isolate Salmonella spp. The isolates (n = 16) were identified using the multiplex-touchdown PCR and assessed their antimicrobial susceptibility against 11 antimicrobial agents. Finally, three isolates with the highest MAR index were subjected to SGF survival tests. It was observed that 17.8 % of flies (n = 16/90) harbouring Salmonella, out of which 10 % (n = 9/90) was S. Enteritidis, 2.2 % (n = 2/90) was S. Typhimurium, and 5.6 % was unidentified serotypes of Salmonella enterica subsp. I. 43.8 % (n = 7/16) were confirmed as MAR, and they were observed to be resistant against ampicillin, chloramphenicol, kanamycin, streptomycin, and nalidixic acid. Three strains, F35, F75, and F85 demonstrated the highest MAR index and were able to survive (>6-log10) in the SGF (180 min), indicating their potential virulence and invasiveness. This study provides significant insights into the prevalence and severity of MAR nontyphoidal Salmonella harboured by filth flies in wet markets, which may help inform strategies for controlling the spread and outbreak of foodborne disease.

Biofilm formation, antimicrobial resistance genes, and genetic diversity of Salmonella enterica subspecies enterica serotype Enteritidis isolated from food and animal sources in Iran

OBJECTIVES

Salmonella enterica serovar Entritidis is an important pathogen in foodborne diseases and causes gastroenteritis. Several studies have investigated the genetic diversity of the strains of this bacterium. However, our knowledge of the discriminatory power of the molecular methods is limited.

METHODS

In total, 34 strains of S. enteritidis were isolated from food related to animals. Antibiotic resistance of the strains, antibiotic resistance genes, and biofilm formation capacity of the strains were evaluated. For the genetic analysis of the strains, PFGE was performed using AvrII restriction enzyme.

RESULTS

Among the tested antibiotics, cefuroxime, nalidixic acid, and ciprofloxacin showed the highest resistance rates (79.4%, 47%, and 44.2%, respectively). Only three antibiotic-resistance genes were identified in these strains (blaTEM: 67.6%, tetA: 9%, and sul2: 3%). In total, 91% of the strains were biofilm producers. Clustering of strains using AvrII for 26 samples with the same XbaI PFGE profile showed that these strains were in one clone and had high homogeneity.

CONCLUSIONS

In conclusion, it is better to use a combination of several typing methods for typing strains that are genetically very close so that the results are reliable.

Microbial Contamination of Bedding Material: One Health in Poultry Production

In poultry farms, the mixture of bedding material, chicken excrement, and feathers seems to play an important role in pathogen development which may contribute to a potential risk of zoonosis, spreading the disease through the food chain. The purpose of this study was to analyze microbial contamination in bedding material and other matrices as well as potential antimicrobial resistances in chicken production facilities, and also to identify the sampling techniques and assays used. This study evidences the available data published, following the PRISMA methodology. Among the environmental samples, surface swabs were frequently used as a passive sampling technique. Morphological identification was performed in all studies. From all the matrices, the bedding material was the most contaminated. Most studies focused on bacterial contamination, with Salmonella sp. and Campylobacter sp. being commonly reported and three studies evidenced fungal contamination, being Penicillium sp.- and Aspergillus sp.-dominant. Mycotoxin assessment was only performed in one study, being identified in all bedding samples. The screening for bacteria resistance evidenced bacteria multidrug resistance; however, fungal susceptibility to azoles was not assessed in any of the analyzed studies. Briefly, this review evidences the microbial contamination in poultry facilities, emphasizing animals' bedding as a potential source of contamination. Additionally, this study contributes to a sampling and analysis protocol proposal to assess the microbial contamination in this setting. Additionally, the knowledge gaps identified highlight the need of further research regarding microbial contamination and toxicological potential on animals' bedding in order to mitigate the exposure in poultry pavilions.

Use of Phages to Treat Antimicrobial-Resistant Salmonella Infections in Poultry

Simple Summary

Salmonellosis, an infection in humans and animals caused by Salmonella spp., poses a major concern to public health and food safety worldwide. Antibiotics are mostly prescribed to treat salmonellosis. Unfortunately, indiscriminate use of antibiotics leads to the emergence and transmission of multidrug-resistant Salmonella spp. As antibiotics are becoming increasingly ineffective, infections caused by MDR strains will be difficult to manage. The search for an alternative to antibiotics has led scientists to give renewed attention on phage therapy. Though commercial use of phages for controlling Salmonella in poultry is still in its early stage, the use of lytic phages is considered an environmentally friendly, cost-effective, and sustainable antimicrobial approach. Moreover, it provides advantages over antibiotics in terms of specificity, cost of development, resistance, and genetic amenability. Studies on laboratory and field scale use show promise on the effectiveness of phages against MDR Salmonella spp. However, inadequate data on safety of phage use, phage stability, and lack of regulatory framework remain major obstacles in the commercial application of phages. Our article provides a comprehensive overview on global prevalence and antimicrobial resistance of Salmonella in poultry, the efforts to control Salmonella using phage therapy, and challenges as well as future prospects of phage therapy.

Abstract

Salmonellosis is one of the most common bacterial infections that impacts both human health and poultry production. Although antibiotics are usually recommended for treating Salmonella infections, their misuse results in the evolution and spread of multidrug-resistant (MDR) bacteria. To minimize the health and economic burdens associated with antimicrobial resistance, a novel antibacterial strategy that can obliterate pathogens without any adverse effects on humans and animals is urgently required. Therefore, therapeutic supplementation of phages has gained renewed attention because of their unique ability to lyse specific hosts, cost-effective production, environmentally-friendly properties, and other potential advantages over antibiotics. In addition, the safety and efficacy of phage therapy for controlling poultry-associated Salmonella have already been proven through experimental studies. Phages can be applied at every stage of poultry production, processing, and distribution through different modes of application. Despite having a few limitations, the optimized and regulated use of phage cocktails may prove to be an effective option to combat infections caused by MDR pathogens in the post-antibiotic era. This article mainly focuses on the occurrence of salmonellosis in poultry and its reduction with the aid of bacteriophages. We particularly discuss the prevalence of Salmonella infections in poultry and poultry products; review the trends in antibiotic resistance; and summarize the application, challenges, and prospects of phage therapy in the poultry industry.

Detection of Bacterial Pathogens and Antibiotic Residues in Chicken Meat: A Review

Detection of pathogenic microbes as well as antibiotic residues in food animals, especially in chicken, has become a matter of food security worldwide. The association of various pathogenic bacteria in different diseases and selective pressure induced by accumulated antibiotic residue to develop antibiotic resistance is also emerging as the threat to human health. These challenges have made the containment of pathogenic bacteria and early detection of antibiotic residue highly crucial for robust and precise detection. However, the traditional culture-based approaches are well-comprehended for identifying microbes. Nevertheless, because they are inadequate, time-consuming and laborious, these conventional methods are not predominantly used. Therefore, it has become essential to explore alternatives for the easy and robust detection of pathogenic microbes and antibiotic residue in the food source. Presently, different monitoring, as well as detection techniques like PCR-based, assay (nucleic acid)-based, enzyme-linked immunosorbent assays (ELISA)-based, aptamer-based, biosensor-based, matrix-assisted laser desorption/ionization-time of flight mass spectrometry-based and electronic nose-based methods, have been developed for detecting the presence of bacterial contaminants and antibiotic residues. The current review intends to summarize the different techniques and underline the potential of every method used for the detection of bacterial pathogens and antibiotic residue in chicken meat.

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.

Characterization and application of antimicrobials produced by Enterococcus faecium S6 isolated from raw camel milk

The emergence of antimicrobial resistance in the food chain and the consumer's demand for safe food without chemical preservatives have generated much interest in natural antimicrobials. Thus, our main goal was to study the mode of action of the crude extract, the enterocins, and the organic acid produced by a bacteriocinogenic Enterococcus faecium strain S6 previously isolated from raw camel milk. Then, we aimed to evaluate their potential application in a food system. These antimicrobials exhibited antimicrobial activity against Listeria monocytogenes, Salmonella enterica, and Escherichia coli. The enterocins were synthesized as primary metabolites beginning at the lag phase, with optimal production at the exponential and stationary phases. The antimicrobials had a direct effect in extending the lag phase of L. monocytogenes, along with a significant inhibitory activity. The organic acid, in particular, inhibited both L. monocytogenes and S. enterica by inducing a total lysis and damage of the cell wall. The enterocins acted on disrupting the cell wall with pore formation, leading to cell death. Moreover, the crude extract revealed a combined inhibitory activity between enterocins and organic acid. Furthermore, the antimicrobials showed promising results through inhibiting L. monocytogenes cells in milk samples up to 1 wk at 4°C.

Childhood Diarrhoea in the Eastern Mediterranean Region with Special Emphasis on Non-Typhoidal Salmonella at the Human⁻Food Interface

Diarrhoeal disease is still one of the most challenging issues for health in many countries across the Eastern Mediterranean region (EMR), with infectious diarrhoea being an important cause of morbidity and mortality, especially in children under five years of age. However, the understanding of the aetiological spectrum and the burden of enteric pathogens involved in diarrhoeal disease in the EMR is incomplete. Non-typhoidal Salmonella (NTS), the focus of this review, is one of the most frequently reported bacterial aetiologies in diarrhoeal disease in the EMR. Strains of NTS with resistance to antimicrobial drugs are increasingly reported in both developed and developing countries. In the EMR, it is now widely accepted that many such resistant strains are zoonotic in origin and acquire their resistance in the food-animal host before onward transmission to humans through the food chain. Here, we review epidemiological and microbiological aspects of diarrhoeal diseases among children in the EMR, with emphasis on the implication and burden of NTS. We collate evidence from studies across the EMR on the zoonotic exposure and antimicrobial resistance in NTS at the interface between human and foods of animal origin. This review adds to our understanding of the global epidemiology of Salmonella with emphasis on the current situation in the EMR.

Distribution and antimicrobial activity of lactic acid bacteria from raw camel milk

Consumer demand for natural pathogen-control agents for substitution of synthetic food preservatives and traditional antibiotics is increasing. This study aimed to reveal the distribution of lactic acid bacteria (LAB) in raw camel milk and to characterize their antimicrobial traits. The genetic identification by 16S rRNA sequencing of 58 LAB isolates showed the predominance of Enterococcus (24.2%), Lactococcus (22.4%) and Pediococcus (20.7%) genera in raw camel milk. These genera exhibited inhibitory activity against a broad spectrum of Gram-positive and Gram-negative bacteria including multidrug-resistant Salmonella. Among these LAB, two isolates-identified as Pediococcus pentosaceus CM16 and Lactobacillus brevis CM22-were selected for their strong bacteriocinogenic anti-listerial activity estimated at 1600 and 800 AU/mL, respectively. The bacteriocins produced were partially purified by ammonium sulphate precipitation and gel filtration and then biochemically characterized. The proteinaceous nature of bacteriocins was confirmed by the susceptibility to enzymes. These bacteriocins showed significant technological characteristics such as heat-resistance, and stability over a wide range of pH (2.0-10.0). In conclusion, these results indicated that Pediococcus pentosaceus CM16 and Lactobacillus brevis CM22 could be useful as potential probiotics. Moreover, their partially purified bacteriocins may play an important role as food preservatives and feed additives. To our knowledge, this is the first report describing the distribution of LAB population in raw camel milk and the characterization of their bacteriocins from the Arabian Peninsula of western Asia.

Antibiotic-Resistant Salmonella in the Food Supply and the Potential Role of Antibiotic Alternatives for Control

Salmonella enterica is one of the most ubiquitous enteropathogenic bacterial species on earth, and comprises more than 2500 serovars. Widely known for causing non-typhoidal foodborne infections (95%), and enteric (typhoid) fever in humans, Salmonella colonizes almost all warm- and cold-blooded animals, in addition to its extra-animal environmental strongholds. The last few decades have witnessed the emergence of highly virulent and antibiotic-resistant Salmonella, causing greater morbidity and mortality in humans. The emergence of several Salmonella serotypes resistant to multiple antibiotics in food animals underscores a significant food safety hazard. In this review, we discuss the various antibiotic-resistant Salmonella serotypes in food animals and the food supply, factors that contributed to their emergence, their antibiotic resistance mechanisms, the public health implications of their spread through the food supply, and the potential antibiotic alternatives for controlling them.

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.

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Water availability, geographic and political overview of each of the Gulf States.

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Gastrointestinal and foodborne diseases affecting citizens and expatriate workers.

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Relevant research and government policies and actions to reduce foodborne disease.

Prevalence and antimicrobial resistance ofSalmonellaserovars isolated from poultry in Ghana

Poultry are possible sources of non-typhoidalSalmonellaserovars which may cause foodborne human disease. We conducted a cross-sectional study to determine the prevalence ofSalmonellaserovars in egg-laying hens and broilers at the farm level and their susceptibility to antimicrobials commonly used in the poultry industry in Ghana. Sampling of faeces by a sock method (n= 75), dust (n= 75), feed (n= 10) and drinking water (n= 10) was performed at 75 commercial egg-laying and broiler farms in two regions of Ghana and skin neck (n= 30) at a local slaughterhouse from broilers representing different flocks.Salmonellawas detected in 94/200 (47%) samples with an overall flock prevalence of 44·0%. Sixteen different serovars were identified withS. Kentucky (18·1%),S. Nima (12·8%),S. Muenster (10·6%),S. Enteritidis (10·6%) andS. Virchow (9·6 %) the most prevalent types. The predominant phage type ofS. Enteritidis was PT1. All strains were susceptible to cefotaxime, ceftazidime and cefoxitin. Fifty-seven (60·6%) strains were resistant to one or more of the remaining nine antimicrobials tested by disk diffusion, of which 23 (40·4%) showed multi-resistance (resistance to ⩾3 classes of antimicrobials). Of the resistant strains (n= 57), the most significant were to nalidixic acid (89·5%), tetracycline (80·7%), ciprofloxacin (64·9%), sulfamethazole (42·1%), trimethoprim (29·8%) and ampicillin (26·3%). AllS.Kentucky strains were resistant to more than two antimicrobials and shared common resistance to nalidixic acid or ciprofloxacin and tetracycline, often in combinations with other antimicrobials. PFGE analysis usingXbaI ofS. Kentucky demonstrated one dominant clone in the country. In conclusion, poultry produced in Ghana has a high prevalence of multi-resistantSalmonellaand the common finding of clonalS.Kentucky in the Kumasi area warrants further investigations into the epidemiology of this serovar. There is an urgent need for surveillance and control programmes onSalmonellaand use of antimicrobials in the Ghanaian poultry industry to protect the health of consumers.

β-Lactamase production in key gram-negative pathogen isolates from the Arabian Peninsula

SUMMARY Infections due to Gram-negative bacilli (GNB) are a leading cause of morbidity and mortality worldwide. The extent of antibiotic resistance in GNB in countries of the Gulf Cooperation Council (GCC), namely, Saudi Arabia, United Arab Emirates, Kuwait, Qatar, Oman, and Bahrain, has not been previously reviewed. These countries share a high prevalence of extended-spectrum-β-lactamase (ESBL)- and carbapenemase-producing GNB, most of which are associated with nosocomial infections. Well-known and widespread β-lactamases genes (such as those for CTX-M-15, OXA-48, and NDM-1) have found their way into isolates from the GCC states. However, less common and unique enzymes have also been identified. These include PER-7, GES-11, and PME-1. Several potential risk factors unique to the GCC states may have contributed to the emergence and spread of β-lactamases, including the unnecessary use of antibiotics and the large population of migrant workers, particularly from the Indian subcontinent. It is clear that active surveillance of antimicrobial resistance in the GCC states is urgently needed to address regional interventions that can contain the antimicrobial resistance issue.

Salmonella can reach tomato fruits on plants exposed to aerosols formed by rain

Outbreaks of Salmonella enterica have been associated with tomatoes and traced back to production areas but the spread of Salmonella in agricultural fields is still poorly understood. Post-rain Salmonella transfer from a point source to the air and then to tomato plants was evaluated. GFP-labeled kanamycin-resistant S. enterica serovar Typhimurium (10(8)CFU/mL) with and without expression of the rdar morphotype (rough colonies; cells with fimbriae and cellulose) was used as the point source in the center of a rain simulator. Rain intensities of 60 and 110 mm/h were applied for 5, 10, 20, and 30 min. Petri dishes with lactose broth and tomato plants with fruit (50-80 cm high) were placed in the simulator after the rain had ceased. Salmonella recovery from air was maximum (300 CFU/plate) after a rain episode of 60 mm/h for 10 min at distances of at least 85.5 cm above the source and when the rdar morphotype strain was used. Small scale experiments showed that the smooth-colony strain without fimbriae precipitated from the air in significantly higher numbers than the rdar strain. Transfer of aerial Salmonella with the rdar morphotype to tomato fruits on plants followed a beta distribution (2.5950, 4.7393) within the generalized range from 0 to 30 min of rain. Results show for the first time that Salmonella may transfer from rain to the air and contaminate tomato fruits at levels that could possibly be infectious to humans.

Prevalence and antimicrobial resistance of Salmonella serotypes in chickens from retail markets in Yaounde (Cameroon)

From February 2006 to January 2007, 150 chickens were collected from eight retail markets in Yaounde, and 90 (60%) tested positive for Salmonella. Seventy-nine chickens were contaminated with only one Salmonella serotype, 10 with two different serotypes, and 1 with four serotypes. The most prevalent serotypes were Enteritidis (47 strains) and Hadar (29 strains). The isolates were tested for their susceptibilities to amoxicillin, amoxicillin/clavulanic acid, cefoxitin, cefotaxime, gentamicin, streptomycin, tetracycline, chloramphenicol, sulfonamides, nalidixic acid, ciprofloxacin, and trimethoprim/sulfamethazole by disk diffusion assay. Minimum inhibitory concentrations of ampicillin, streptomycin, tetracycline, sulfonamides, and nalidixic acid were determined for the resistant strains by agar dilution method. Eleven isolates (10.7%) of the 103 tested were susceptible to all antimicrobials. Resistance was most observed to tetracycline (84.5%), streptomycin (44.7%), and nalidixic acid (34%). Forty-one isolates (39.8%) were multidrug resistant (resistant to three or more antimicrobials from different classes), of which 68.3% were Hadar and 21.9% Enteritidis. The most frequent resistant pattern in Hadar was streptomycin-tetracycline-nalidixic acid. These results highlight once more the need for surveillance of Salmonella contamination in poultry.

Antimicrobial resistance in selected bacteria from poultry

This paper reviews the present state of antimicrobial resistance (AMR) in the zoonotic bacteria Salmonella, Campylobacter jejuni and Campylobacter coli, and in Escherichia coli from chickens and turkeys. For Salmonella, the frequencies and patterns of AMR vary depending on time, region, serovar, the particular farm, layers versus broilers, and the antimicrobial agent. There is usually a higher frequency of AMR in Salmonella from turkeys compared with Salmonella from chickens. Clonal and horizontal transmission of AMR occur and there is concern about the spread of transmissible plasmids that encode extended spectrum cephalosporinases. Resistance to fluoroquinolones is generally low. For Campylobacter, resistance to tetracycline is usually at moderate to high frequency, resistance to quinolones/fluoroquinolones varies from low to high, and resistance to macrolides is usually low. There are high levels of fluoroquinolone resistance in some countries. Avian pathogenic E. coli are often highly resistant, especially to tetracycline, streptomycin, and sulfonamides. Plasmid-mediated resistance is common. High levels of resistance to ciprofloxacin have been reported from China. Commensal E. coli from poultry have similar patterns of resistance but at lower frequencies. Integron associated resistance occurs commonly in Salmonella and E. coli but has not been detected in Campylobacter.