Reservoirs For Foodborne Pathogens Research Articles

Bacteriophage-mediated approaches for biofilm control.

Biofilms are complex microbial communities in which planktonic and dormant bacteria are enveloped in extracellular polymeric substances (EPS) such as exopolysaccharides, proteins, lipids, and DNA. These multicellular structures present resistance to conventional antimicrobial treatments, including antibiotics. The formation of biofilms raises considerable concern in healthcare settings, biofilms can exacerbate infections in patients and compromise the integrity of medical devices employed during treatment. Similarly, certain bacterial species contribute to bulking, foaming, and biofilm development in water environments such as wastewater treatment plants, water reservoirs, and aquaculture facilities. Additionally, food production facilities provide ideal conditions for establishing bacterial biofilms, which can serve as reservoirs for foodborne pathogens. Efforts to combat antibiotic resistance involve exploring various strategies, including bacteriophage therapy. Research has been conducted on the effects of phages and their individual proteins to assess their potential for biofilm removal. However, challenges persist, prompting the examination of refined approaches such as drug-phage combination therapies, phage cocktails, and genetically modified phages for clinical applications. This review aims to highlight the progress regarding bacteriophage-based approaches for biofilm eradication in different settings.

Evaluation of Thymol-β-d-Glucopyranoside as a Potential Prebiotic Intervention to Reduce Carriage of Zoonotic Pathogens in Weaned and Feeder Pigs.

The gut of food-producing animals is a reservoir for foodborne pathogens. Thymol is bactericidal against foodborne pathogens but rapid absorption of thymol from the proximal gut precludes the delivery of effective concentrations to the lower gut where pathogens mainly colonize. Thymol-β-d-glucopyranoside is reported to be more resistant to absorption than thymol in everted jejunal segments and could potentially function as a prebiotic by resisting degradation and absorption in the proximal gut but being hydrolysable by microbial β-glycosidase in the distal gut. Previous in vitro studies showed bactericidal effects of thymol-β-d-glucopyranoside against Campylobacter, Escherichia coli, and Salmonella enterica serovar Typhimurium in the presence but not absence of intestinal microbes expressing β-glycosidase activity, indicating that hydrolysis was required to obtain antimicrobial activity. Presently, the oral administration of thymol-β-d-glucopyranoside was studied to examine the effects on intestinal carriage of Campylobacter, E. coli, and S. Typhimurium in swine. The effects of thymol-β-d-glucopyranoside or thymol on antimicrobial sensitivity of representative E. coli isolates and characterized Salmonella strains were also explored. Results from two in vivo studies revealed little antimicrobial effects of thymol-β-d-glucopyranoside on Campylobacter, E. coli, or S. Typhimurium in swine gut. These findings add credence to current thinking that hydrolysis and absorption of thymol-β-d-glucopyranoside and thymol may be sufficiently rapid within the proximal gut to preclude delivery to the distal gut. Antibiotic susceptibilities of selected bacterial isolates and strains were mainly unaffected by thymol. Further research is warranted to overcome obstacles, preventing the delivery of efficacious amounts of thymol-β-d-glucopyranoside to the lower gut.

Multidrug resistant Salmonella spp. and Escherichia coli from a popular Ready-to-Eat local food (Fufu) from commercial food vendors in Ghana

Microbial contamination of vended foods are of public health importance due to the potential of becoming a reservoir of foodborne pathogens and resistant strains of bacteria. This study looked at the presence of pathogenic bacteria in a popular Ready-To-Eat (RTE) traditional food, Fufu in Ghana. Sixty (60) Fufu samples were obtained from various food joints categorized as Opened, Semi-closed and Closed or Restaurants. Samples were processed and analyzed using standard bacteriological methods. The susceptibility profiles of the isolates were obtained by using the Kirby-Bauer disk diffusion method with the EUCAST guidelines with the five antibiotics. Prevalence of E. coli was 85% and Salmonella species was 68%. Microbial count of isolated E. coli ranged from 0 to 3×106 cfu/ml. There were no significant differences (p>0.05) among the different modes of operations. Fufu samples from Opened, Semi-closed and Closed joints were respectively contaminated with E. coli and Salmonella species as follows: 92%, 76%; 80%, 60% and 80%, 65%. The Salmonella species showed highest resistance to erythromycin (58.5%) and E. coli species were commonly resistant to Ceftazidime (88.2%) and Ceftriaxone (94.1%). All isolates were susceptible to nitrofurantoin. Multidrug resistance was detected among 27.5% of E. coli strains and 14.6% of Salmonella species. Fufu from the different eating joints in the Tamale Metropolis were substantially contaminated with multidrug resistant pathogens. The study recommends surveillance studies of resistant pathogens in foods, increased education and training of food vendors on sanitation, food handling and safety practices in the region.

The Role of Peridomestic Rodents as Reservoirs for Zoonotic Foodborne Pathogens.

Although rodents are well-known reservoirs and vectors for a number of zoonoses, the functional role that peridomestic rodents serve in the amplification and transmission of foodborne pathogens is likely underappreciated. Clear links have been identified between commensal rodents and outbreaks of foodborne pathogens throughout Europe and Asia; however, comparatively little research has been devoted to studying this relationship in the United States. In particular, regional studies focused on specific rodent species and their foodborne pathogen reservoir status across the diverse agricultural landscapes of the United States are lacking. We posit that both native and invasive species of rodents associated with food-production pipelines are likely sources of seasonal outbreaks of foodborne pathogens throughout the United States. In this study, we review the evidence that identifies peridomestic rodents as reservoirs for foodborne pathogens, and we call for novel research focused on the metagenomic communities residing at the rodent-agriculture interface. Such data will likely result in the identification of new reservoirs for foodborne pathogens and species-specific demographic traits that might underlie seasonal enteric disease outbreaks. Moreover, we anticipate that a One Health metagenomic research approach will result in the discovery of new strains of zoonotic pathogens circulating in peridomestic rodents. Data resulting from such research efforts would directly inform and improve upon biosecurity efforts, ultimately serving to protect our food supply.

Agricultural intensification heightens food safety risks posed by wild birds

Abstract Agricultural intensification and simplification are key drivers of recent declines in wild bird populations, heightening the need to better balance conservation with food production. This is hindered, however, by perceptions that birds threaten food safety. While birds are known reservoirs of foodborne pathogens, there remains uncertainty about the links between landscape context, farming practices, and actual crop contamination by birds. Here, we examine relationships between landscape context, farming practices, and pathogen contamination by birds using a barrier‐to‐spillover approach. First, we censused bird communities using point count surveys. Second, we collected 2,024 faecal samples from captured birds alongside 1,215 faecal samples from brassica fields and food processing areas across 50 farms spanning the USA West Coast. We then estimated the prevalence of three foodborne pathogens across landscape and livestock intensification gradients. Finally, we quantified the number of plants with faeces. Campylobacter spp. were detected in 10.2% of faeces from captured birds and 13.1% of faeces from production areas. Non‐native birds were 4.1 times more likely to have Campylobacter spp. than native birds. Salmonella spp. were detected in 0.2% of faeces from production areas and were never detected in captured birds. We detected evidence of Shiga toxigenic E. coli in one sample across the >3,200 tested. Campylobacter spp. prevalence in faeces from production areas increased with increasing mammalian livestock densities in the landscape but decreased with increasing amounts of natural habitat. We encountered bird faeces on 3.3% of plants examined. Despite the impact on pathogen prevalence, amount of natural habitat in the landscape did not increase the number of plants with bird faeces, although on‐farm mammalian livestock density slightly did. Synthesis and applications. Food safety and wildlife conservation are often thought to be in conflict. However, our findings suggest that natural habitat around farms may reduce crop contamination rates by birds. This is perhaps because natural habitat can promote native birds that are less likely to harbour foodborne pathogens or because it decreases contact with livestock waste. Our results suggest that preservation of natural habitats around farms could benefit both conservation and food safety, contrary to current standards for ‘best practices’.

Fallow Deer (Dama dama) as a Reservoir of Shiga Toxin-Producing Escherichia coli (STEC).

Simple SummaryInfections caused by Shiga toxin-producing Escherichia (E.) coli (STEC) are the third most typically reported zoonosis within the European Union after campylobacteriosis and salmonellosis. STEC pathogens are responsible for the outbreaks of serious diseases in humans, including haemolytic uraemic syndrome (HUS), haemorrhagic colitis (HC) and diarrhoea (D). Red deer, roe deer and wild boars are important environmental reservoirs of foodborne pathogens that may cause serious diseases in humans and contaminate fresh food products. The occurrence of STEC and attaching and effacing (AE)-STEC in the Polish population of wild fallow deer was analysed in this study. The presence of potentially pathogenic STEC/AE-STEC in fallow deer poses a risk of carcass contamination, which could have serious consequences because venison can also be consumed raw as carpaccio or steak tartare. Only a few reports on wild animals as a reservoir of foodborne pathogens in European countries have been published to date, and the present study attempts to fill in this knowledge gap by assessing the possible epidemiological risk related to STEC/AE-STEC in fallow deer. Three isolates had the virulence profile that is associated with HUS/D/HC according to the FAO/WHO report. The results of this study suggest that fallow deer are carriers of STEC/AE-STEC that are potentially pathogenic to humans.Shiga toxin-producing Escherichia (E.) coli (STEC) are responsible for the outbreaks of serious diseases in humans. Only a few reports on fallow deer as a reservoir of foodborne pathogens have been published to date. The purpose of this study was to determine the occurrence of STEC strains in the fallow deer population in Poland. In all, 94 fallow deer swabs were tested. Polymerase chain reaction (PCR) was performed to detect the virulence profile of stx1, stx2 and eae or aggR genes, to identify the subtypes of stx1 and stx2 genes and to perform O and H serotyping. STEC and attaching and effacing (AE)-STEC were identified in 13 isolates (13.83%). The most hazardous virulence profile was detected in three strains, namely stx2d serotype O103:HNM, eae/stx1a serotype O26:HNM and eae/stx1a serotype O157:H7. The predominant stx gene was stx2, which was identified in 76.92% of isolates. E. coli O157 was detected in 4/94 (4.26%). Other E. coli serogroups, O26, O103, O111 and O145, were identified in 14/94 fallow deer (14.89%). The present findings suggest that fallow deer are carriers of STEC/AE-STEC that are potentially pathogenic to humans.

Efficacy of household washing pre-treatments and cooking methods for reduction of Listeria monocytogenes in artificially contaminated chicken offal

Consumption of chicken offal is common and famous among Malaysians as it is often served as one of the side dishes with rice. Chicken offal can be a potential source of Listeria monocytogenes because slaughtered animals are recognized as a reservoir for foodborne pathogens. L. monocytogenes is a dangerous foodborne pathogen which can cause severe foodborne listeriosis with high fatality rate. This study aimed to determine the efficacy of different washing pre-treatment and cooking methods to reduce L. monocytogenes in artificially contaminated chicken offal. All the washing pre-treatments (dip treatment in different water sources and wash treatment with different water flow rates) showed significant reduction of the pathogen (p<0.05) when the inoculated samples were treated from 2 mins onwards. Washing the inoculated samples under the water flow rate of 2 L/min was the most effective way to reduce the number of L. monocytogenes (approximately 1.97 log reduction after washing for 10 mins). For heat treatment study, deep-frying was the most effective cooking method followed by boiling and pan-frying to reduce L. monocytogenes where all L. monocytogenes cells (7.91 log10 CFU/g) were killed within 45 s under deep-frying treatment. Overall, the study indicated that washing under running tap water (2 L/min) and deep-frying was effective in reducing and controlling the microbial populations during food preparation. The findings from this study can serve as a safe preparation step and cooking guideline. It is necessary to implement safe steps in food handling practices among food handlers to minimize the risk of foodborne infection.

Food-to-Humans Bacterial Transmission.

Microorganisms vehiculated by food might benefit health, cause minimal change within the equilibrium of the host microbial community or be associated with foodborne diseases. In this chapter we will focus on human pathogenic bacteria for which food is conclusively demonstrated as their transmission mode to human. We will describe the impact of foodborne diseases in public health, the reservoirs of foodborne pathogens (the environment, human and animals), the main bacterial pathogens and food vehicles causing human diseases, and the drivers for the transmission of foodborne diseases related to the food-chain, host or bacteria features. The implication of food-chain (foodborne pathogens and commensals) in the transmission of resistance to antibiotics relevant to the treatment of human infections is also evidenced. The multiplicity and interplay of drivers related to intensification, diversification and globalization of food production, consumer health status, preferences, lifestyles or behaviors, and bacteria adaptation to different challenges (stress tolerance and antimicrobial resistance) from farm to human, make the prevention of bacteria-food-human transmission a modern and continuous challenge. A global One Health approach is mandatory to better understand and minimize the transmission pathways of human pathogens, including multidrug-resistant pathogens and commensals, through food-chain.

A study of microbial analysis of fresh fruits and vegetables, in Sagamu markets South-West, Nigeria

Raw and minimally processed fruits and vegetables are essential parts of diets of people around the world. However, these food items have consistently served as vehicles for human diseases worldwide. This study was aimed at determining the microbiological quality of fresh fruits and vegetables sold at Sagamu markets, Ogun state, Nigeria. Twenty different samples of fruits and vegetables were randomly purchased from ten various vendors in Shagamu market, Ogun State, Nigeria. Aerobic plate counts, total coliform counts, yeast, mold counts and antimicrobial susceptibility study using were determined using standard microbiological methods. In Fruits, the isolation rate of Bacillus specie was predominant (44.1%), followed by Klebsiella species (44.0%) while in vegetables, the prevalent rates of 38.3% and 14.4% were respectively recorded by Staphylococcus aureus and Pseudomonas species. Malassezia species and Aspergillus species were the only fungal isolates obtained from the fruits and vegetables. Aspergillus species were predominant in vegetables, with a frequency of 13.3% while both Malassezia and Aspergillus species were observed almost at the same frequently of 24.1% and 24.4% in fruits respectively. This study showed that fruits and vegetable were contaminated with potential food borne pathogens with varying degree of antibiotic resistance thus suggesting that they could act as a vehicle for the dissemination of antibiotic resistant organisms as well as serve as a reservoir of food borne pathogens of public health significance.Keywords: Micro flora, fresh fruits and vegetables, antibiotics resistance

A STUDY OF CROSS-CONTAMINATION OF FOODBORNE PATHOGENS ON THE KITCHEN SURFACES

Cross-contamination provides the opportunity for various of bacteria to be deposited on each of the surface contact during meal preparation. Raw poultry especially raw chicken was the main reservoir of foodborne pathogens that can cause foodborne diseases. Therefore, a study on the potential of cross-contamination contribute to spread E. coli, Salmonella spp. and S. aureus on the kitchen surfaces during chicken preparation was conducted. A total of 36 isolates were collected from six sampling sites before and after the chicken preparation. The enumeration of the bacteria from the sampling sites showed a significant change in the mean total plate counts (TPC) of the isolates before and after the chicken preparation. These results emphasized that cross-contamination occurred around the sampling sites during the preparation of the chicken. Isolation and identification of the three foodborne pathogens, E. coli, Salmonella spp. and S. aureus were carried out on its respectively selective and differential media. The presumptive identified foodborne pathogens were confirmed as E. coli, Salmonella spp. and S. aureus according to their microscopic and biochemical characteristics.

Dietary effects on the microbiological safety of food.

The high mortality rate associated with human infections caused by Escherichia coli strains of the serotype O157:H7 has brought to public attention the importance of ruminants as reservoirs of food-borne pathogens. In addition to established examples such as salmonella, campylobacter and listeria, recent evidence is emerging of the role of food in the transmission of Helicobacter pylori and Mycobacterium paratuberculosis. Food-borne pathogens harboured by ruminants are spread through shedding in the faeces and subsequent faecal contamination of raw food. Ruminant shedding appears to be affected by diet and, of particular concern, may be increased during fasting regimens imposed during transport to the slaughterhouse. The survival of food-borne pathogens in the ruminant gut is affected by many factors including microbe-microbe interactions, interactions involving plant metabolites and the presence of inhibitory end-product metabolites such as short-chain fatty acids. The potential importance of digesta flow and bacterial detachment in shedding of food-borne pathogens is discussed. Experimental procedures with dangerous pathogens have constraints, particularly in animal experimentation. This situation may be overcome by the use of rumen-simulating fermentors. One such system which, like the natural rumen, has a different turnover rate for solid and liquid digesta, was found to maintain rumen-like variables over an 11 d period. This system may prove useful for the study of dietary effects on food-borne pathogens.