Enterobacteriaceae Contamination Research Articles

Reduction of Microbial Contamination of Chechin nchabe (Cooked Fermented Cassava) Produced in Noun (West Cameroon) by a Second Fermentation

The Chechim nchabe is a traditional food widely consumed in Foumban, Foumbot, Koutaba, Massangam, Kouoptamo, Malentouen and Magba, 07 Departments of Noun (West region of Cameroon). It is obtained by fermenting cassava sticks cooked on the surface of river or spring water. Unfortunately, the bad hygienic quality of the environment during production promotes its contamination by pathogenic germs. The objective of this study is to carry out a second fermentation in order to reduce contamination of Chechim nchabe by pathogens germs during production. To achieve this objective, a survey on the socio-economic data, profile of the producers, production protocol and characteristics of product have been realized. After microbiological analysis of Chechim nchabe, a second fermentation was performed in the laboratory. From the results, it appears that all the producers are women, aged between 51 and 58 years and 87% of them not attending school. The water used for soaking the cassava revealed that 54% of women use river water and 46% spring water. The Chechim nchabe samples collected after traditional production in the 07 Departments of Noun, show average contamination of Enterobacteriaceae, moulds, staphylococci, Escherichia coli and lactic acid bacteria with respective concentrations of 4.7; 4.1; 4.4; 4.7 and 4.8 Log10ufc/mL. However, Chechim nchabe produced in urban areas such as Foumbot and Foumban recorded low contamination compared to that produced in rural areas like Massangam, which were heavily contaminated with Escherichia coli and Enterobacteriaceae. It was also noted that the Chechim nchabe produced in spring water is more contaminated than that produced in river water. The second fermentation for 10 hours of Chechim nchabe in a basin, after 12 hours of traditional fermentation, eliminated all of pathogenic germs from Chechim nchabe. This second fermentation of 10 hours could be a solution to guarantee the sanitary quality of Chechim nchabe before its consumption.

Modeling of interventions for reducing external Enterobacteriaceae contamination of broiler carcasses during processing.

This article presents a mathematical model for the Enterobacteriaceae count on the surface of broiler chicken during slaughter and how it may be affected by different processing technologies. The model is based on a model originally developed for Campylobacter and has been adapted for Enterobacteriaceae using a Bayesian updating approach and hitherto unpublished data gathered from German abattoirs. The slaughter process in the model consists of five stages: input, scalding, defeathering, evisceration, washing, and chilling. The impact of various processing technologies along the broiler processing line on the Enterobacteriaceae count on the carcasses' surface has been determined from literature data. The model is implemented in the software R and equipped with a graphical user interface which allows interactively to choose among different processing technologies for each stage along the processing line. Based on the choice of processing technologies the model estimates the Enterobacteriaceae count on the surface of each broiler chicken at each stage of processing. This result is then compared to a so-called baseline model which simulates a processing line with a fixed set of processing technologies. The model calculations showed how even very effective removal of bacteria on the exterior of the carcass in a previous step will be undone by the cross-contamination with leaked feces, if feces contain high concentrations of bacteria.

New insights of bacterial communities in fermented vegetables from shotgun metagenomics and identification of antibiotic resistance genes and probiotic bacteria

Consumption of fermented foods has grown worldwide due to the purported health benefits. It is thus critical to understand fermented foods microbiome that mainly influences the quality and safety of these foods. This study identified bacterial communities, including functional profiles of probiotics and antimicrobial resistance genes (ARGs), in pickled vegetables commonly consumed in the Middle Eastern, African, and Asian sub-continent regions. Eighteen samples from six pickled vegetables were collected from local markets in Saudi Arabia and analyzed using shotgun metagenomic sequencing. Statistical analyses revealed significant distance and separate clustering of bacterial communities among the different pickle types. Species of Levilactobacillus namurensis, Lentilactobacillus buchneri, Lentilactobacillus parafarraginis, Lactiplantibacillus pentosus, Pectobacterium carotovorum, Leuconostoc carnosum, Weissella confuse were found in a range of dominance in most of the samples. Binning revealed 33 high-quality, metagenome-assembled genomes (MAGs), including 4 MAGs representing putatively novel species of Lactobacillus, Alcanivorax, and Dichelobacter. Moreover, 285 ARGs and variants produce resistance against 20 classes of antibiotics were retrieved, mostly from Enterobacteriaceae contigs. The metagenomes harbored relatively high abundances of carbohydrate fermentation enzymes, as well as metabolic pathways for amino acid metabolism, cofactors and vitamins biosynthesis. Overall, by providing a comprehensive overview of bacterial communities and probiotic bacteria in pickled vegetables, the results suggest the need for more hygienic processing to avoid Enterobacteriaceae contamination and ARG spread.

The Investigation of Mycotoxins and Enterobacteriaceae of Cereal-Based Baby Foods Marketed in Turkey.

In this study, a total of 85 cereal-based baby foods with or without milk (four different brands; A, B, C, and D) collected from Ankara local markets, Turkey were analyzed for mycotoxins, total aerobic mesophilic bacteria (TAMB), and Enterobacteriaceae contamination. Baby foods were analyzed for 12 toxicological important mycotoxins such as aflatoxin B1, B2, G1, and G2; fumonisin B1 and B2; ochratoxin A; sterigmatocystin (STE); deoxynivalenol (DON); zearalenone (ZON); and T-2 toxin and HT-2 toxin by LC-MS/MS multi-mycotoxin method. In addition to these mycotoxins, the presence of aflatoxin M1 (AFM1) was investigated in baby foods containing milk. The classical culture method was used for microbiological analysis. Consequently, at least one mycotoxin was detected in 69.41% of the total samples. The most frequently detected mycotoxins were STE (34.12%) and HT-2 (34.12%). However, AFM1 was not detected in any of the baby foods containing milk. Also, TAMB and Enterobacteriaceae were isolated from 30.59% and 10.59% of samples, respectively. As a result, it was determined that the mycotoxin levels in the analyzed samples were in accordance with the mycotoxin levels specified in the Turkish Food Codex.

Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae in Fresh Produce.

Fresh vegetables are an essential part of a healthy diet, but microbial contamination of fruits and vegetables is a serious concern to human health, not only for the presence of foodborne pathogens but because they can be a vehicle for the transmission of antibiotic-resistant bacteria. This work aimed to investigate the importance of fresh produce in the transmission of extended-spectrum β-lactamases (ESBL)-producing Enterobacteriaceae. A total of 174 samples of vegetables (117) and farm environment (57) were analysed to determine enterobacterial contamination and presence of ESBL-producing Enterobacteriaceae. Enterobacterial counts above the detection limit were found in 82.9% vegetable samples and 36.8% environmental samples. The average count was 4.2 log cfu/g or mL, with a maximum value of 6.2 log cfu/g in a parsley sample. Leafy vegetables showed statistically significant higher mean counts than other vegetables. A total of 15 ESBL-producing isolates were obtained from vegetables (14) and water (1) samples and were identified as Serratia fonticola (11) and Rahnella aquatilis (4). Five isolates of S. fonticola were considered multi-drug resistant. Even though their implication in human infections is rare, they can become an environmental reservoir of antibiotic-resistance genes that can be further disseminated along the food chain.

β-Lactam and Fluoroquinolone-Resistant Enterobacteriaceae Recovered from the Environment of Human and Veterinary Tertiary Care Hospitals.

The dissemination of Enterobacteriaceae expressing resistance to clinically important antibiotics such as extended-spectrum cephalosporins (ESC), carbapenems, and fluoroquinolones is of critical concern to both human and veterinary medicine. In healthcare facilities, the movement of patients, personnel, and equipment provides an opportunity for Enterobacteriaceae carrying antibiotic resistance genes to disseminate in the hospital environment where they pose a threat to patients, staff, and hospital visitors. We collected environmental samples using electrostatic cloths to estimate the frequency of resistant Enterobacteriaceae contamination on human and veterinary hospital surfaces. Samples were enriched in nutrient broth modified with antibiotics to provide specific selection pressure to select for bacteria expressing AmpC β-lactamase (blaCMY), extended-spectrum β-lactamase (ESBL, blaCTX-M), carbapenemase, quinolone, and fluoroquinolone-resistant phenotypes. A total of 31 contact surfaces were sampled at each of five visits to two human hospitals. In addition, 34 surfaces were sampled at each of three visits to a veterinary hospital serving both farm animal and companion animal patients. Isolates expressing the blaCMY phenotype were recovered from 0.6%, 100%, and 18.2% of human hospitals, veterinary farm animal, and veterinary companion animal hospital surfaces, respectively. Isolates expressing the blaCTX-M phenotype were recovered from 0.6%, 55%, and 16.7% of human hospitals, farm animal, and companion animal veterinary hospital surfaces, respectively. Carbapenemase-producing Enterobacteriaceae (CPE) were detected from 1.3% of human hospital surfaces, but none were recovered from the veterinary hospital. Fluoroquinolone resistance was detected in 0.6%, 5.0%, and 37.9% of human hospitals, farm animal, and companion animal veterinary hospital surfaces, respectively. Our results indicate that ESC and fluoroquinolone-resistant Enterobacteriaceae can contaminate surfaces in both human and veterinary medical settings, with higher prevalence observed in veterinary hospitals, although the recovery of CPE from human hospital environments is concerning. Hospital medical trolleys or carts may serve as fomites for the dissemination of clinically relevant resistant bacteria.

DETERMINATION OF MICROBIAL CONTAMINATION, PH AND TEMPERATURE CHANGES IN SHEEP AND CATTLE CARCASSES DURING THE SLAUGHTER AND PRE-COOLING PROCESSES IN KONYA, TURKEY

This study was conducted to determine microbial contamination, pH and internal temperature changes in sheep and cattle carcasses during slaughter and chilling stages. Samples were analysed for the presence of Salmonella spp. and Enterobacteriaceae and aerobic colony counts (ACC) were performed. Air sampling was performed in slaughtering areas and chilling rooms. Mean values of ACCs were between 2.57 ± 0.61 and 4.71 ± 0.24 log CFU/cm2 and between 3.51 ± 0.48 and 5.19 ± 0.28 log CFU/cm2, whereas Enterobacteriaceae counts were between 0.89 ± 0.46 and 2.61 ± 0.10 log CFU/cm2 and between 0.55 ± 0.37 and 3.63 ± 0.39 log CFU/cm2 in cattle and sheep carcasses, respectively. Enterobacteriaceae contamination in the shoulder region of cattle carcasses after washing, Enterobacteriaceae contamination in all regions in sheep carcasses after chilling and ACC in the shoulder region of sheep carcasses after chilling all exceeded the limits of EC regulation (EC No 2073/2005).

Escherichia coli hyperepidemic clone ST410-A harboring blaCTX-M-15 isolated from fresh vegetables in a municipal market in Quito-Ecuador

Dissemination of Extended spectrum β-lactamases (ESBL) Enterobacteriaceae is a major medical threat. Vegetables and fruits, which are usually consumed raw, are a very suitable pathway for the spread of these bacteria from farm-to-fork. However, limited information exists regarding resistant bacteria and epidemic clones that are disseminated in vegetables and tap water in South America. We processed a total of 90 samples in triplicate of nine typically consumed raw vegetables from a central municipal market, and tap water samples were processed from twenty-one locations in Quito, Ecuador. The samples were analyzed for total coliforms and ESBL Enterobacteriaceae contamination using the dilution filtration method. ESBL Escherichia coli isolates were phenotypically and genotypically characterized. The water was free of Enterobacteriaceae, but all the vegetables and fruits (except for blackberries) presented total coliform counts. Watercress had the highest load of total coliforms (3.3 × 10E4). ESBL E. coli was detected in alfalfa, leaf lettuce and parsley/cilantro samples. Alfalfa had the highest load of ESBL E. coli/total coliforms (1/3.3 × 10E2). We identified E. coli ST44-A and ST410-A harboring blaCTX-M-15 downstream of ISEcp1. Alfalfa and parsley/cilantro were contaminated with hyperepidemic E. coli ST410-A, which was resistant to quinolones and harbored blaCTX-M-15. For the first time, we report ESBL E. coli ST410-A from vegetables and express an alert regarding the health risk this could represent.

Enterobacteriaceae Antibiotic Resistance in Ready-to-Eat Foods Collected from Hospital and Community Canteens: Analysis of Prevalence

Foodborne diseases and antibiotic resistance are serious widespread health problems in the contemporary world. In this study, we compared the microbiological quality of ready-to-eat (RTE) foods found in community canteens versus hospital canteens in Rome, Italy, focusing on detection and quantification of Enterobacteriaceae and the antibiotic resistance of these bacteria. Our findings show a remarkable difference in Enterobacteriaceae contamination between RTE foods distributed in community canteens (33.5% of samples) and those distributed in hospital canteens (5.3% of samples). This result highlights greater attention to good manufacturing practices and good hygiene practices by the food operators in hospitals compared with food operators in community canteens. As expected, a higher percentage of cold food samples (70.9%) than of hot food samples (10.8%) were positive for these bacteria. Excluding the intrinsic resistance of each bacterial strain, 92.3% of the isolated strains were resistant to at least one antibiotic, and about half of the isolated strains were classified as multidrug resistant. The prevalence of multidrug-resistant strains was 50% in the community samples and 33.3% in hospital canteens. Our results indicate that approximately 38% of RTE foods provided in community canteens is not compliant with microbiological food safety criteria and could be a special risk for consumers through spread of antibiotic-resistant strains. Hygienic processing and handling of foods is necessary for both hospital and community canteens.

A Nosocomial Foodborne Outbreak of a VIM Carbapenemase-Expressing Citrobacter freundii.

A foodborne outbreak of VIM carbapenemase-expressing Citrobacter freundii (CPC) occurred between February 2016 and June 2016 at a major university hospital in Germany. An explosive increase in CPC isolated from rectal swabs of patients during weekly routine screening led to the declaration of an outbreak. A hospital-wide prevalence screening was initiated as well as screening of all patients on admission and before transfer to another ward, canteen staff, patient rooms, medical and kitchen inventory, and food. Swabs were streaked out on selective plates. All CPC isolates were analyzed using mass spectrometry, and selected isolates were analyzed using whole-genome sequencing. A total of 76 were identified; most were unrelated cases in different wards. The CPC was isolated from retained samples of prepared vegetable salads and puddings and from a mixing machine used to prepare these foods only after an overnight culture. The immediate ban on serving potential source food resulted in a sharp decline and finally disappearance of novel cases. Repeated testing of presliced vegetables showed a high degree of contamination with C. freundii without a carbapenemase, indicating a possible source. An explosive increase in carbapenemase-expressing Enterobacteriaceae contamination may have been caused by a foodborne source, and presliced vegetables should be taken into account as a putative pathogen repository. These findings underline the importance of appropriate cooling, transport, reheating, and distribution of meals and indicate that probing of nonorganic surfaces is limited by low sensitivity, which may be increased by additional overnight cultivation in appropriate media.

Haemorrhagic bowel syndrome in fattening pigs

BackgroundHaemorrhagic bowel syndrome (HBS) is a sporadically occurring disorder in fattening pigs, characterized by sudden death in combination with severe abdominal distension and intense red colouration of the intestine. Deep understanding of aetiology and pathogenesis of HBS are still lacking, although several risk factors are known.Case presentationIn a continuously stocked fattening farm with 1500 pigs and liquid feeding based on whey, the mortality rate increased from 1.7% to 3.5% during summer time. Sporadic sudden death of growing pigs occurred along with severe abdominal distension as the main sign in these animals. All batches arriving at the farm received in-feed medication with Tiamulin hydrogen fumarate (2 mg/kg body weight/day; according to the license for use in Switzerland) due to detection of Brachyspira hyodysenteriae in the past, although a partial sanitation had been conducted thereafter. No changes of the origins, housing and the feeding procedure were reported. A herd examination was conducted revealing a hygiene problem in the feeding system. For further diagnostics a necropsy was performed, showing a pale carcass with a bloated abdomen due to a haemorrhagic infarction of part of the small intestine caused by a mesenteric torsion. Furthermore, a feed analysis was conducted, revealing a pH-value of 5 in the liquid feed, and a severe contamination with Enterobacteriaceae was detected. Based on these examinations, HBS was diagnosed. Subsequently, the farmer controlled the pH-value of the liquid feed with formic acid, improved the cleaning procedure of the liquid feeding system and stopped the in-feed medication. Following the implementation of these measures, key performance indicators improved significantly, but 4 months later the same clinical manifestation occurred again. This time huge variations in the pH-value of the liquid feed between different feeding times were recorded and were attributed to improper mixing of the formic acid in the whey tank. After implementation of a technical solution to control the pH-value, the health status improved again.ConclusionIn the present case, it is likely that the cause of the clinical manifestation of HBS was a contamination of Enterobacteriaceae in the liquid feed facilitated by a hygiene problem in the feeding system, and a chronic dysbacteriosis of the intestinal tract due to the non-justified routine use of antimicrobials. Speculatively, the prophylactic antimicrobial treatment was unnecessary and might even have exacerbated the clinical problem.

A Survey of Enterobacteriaceae and Resistance of Greater Rhea (Rhea Americana) Eggs to Experimental Contamination by Salmonella Enteritidis

Eggs have protective structures against possible contamination by bacteria and fungi. Pathogenic bacteria such as Salmonella spp. are therefore rarely found in adequate sanitary conditions. Few studies about the contamination of ratite eggs have been reported, and although some studies have focused on ostrich eggs, there is no information about Greater Rhea ( Rhea americana) eggs. The microorganisms that contaminate ratite eggs do not differ from those that affect other bird species. The purpose of this study was to characterise contamination in 16 eggs, supplied by a commercial breeding facility, by Enterobacteriaceae contamination and to assess the in vitro resistance to experimental contamination by Salmonella Enteritidis using analytical tests following the guidelines of the Georgia Poultry Laboratory. These elements are critical to the storage period, quality and physicochemical parameters. The results revealed the presence of the genera Proteus, Klebsiella, Citrobacter and Enterobacter related to the location of nests. Greater Rhea eggs were also found to be highly resistant to experimental infection by Salmonella Enteritidis.

Extended-spectrum β-lactamase–producing Enterobacteriaceae in cell phones of health care workers from Peruvian pediatric and neonatal intensive care units

Health care workers (HCWs) use their mobile phones during working hours or medical care. There is evidence that the instruments are colonized with pathogenic microorganisms. Here, we describe levels of Enterobacteriaceae contamination (EC) in cell phones and the risk factors associated with EC in Peruvian intensive care units (ICUs). This was a 5-month cohort study among 114 HCWs of 3 pediatric and 2 neonatology ICUs from 3 Peruvian hospitals. A baseline survey collected data on risk factors associated with EC. Swabs were collected from HCWs' phones every other week. Three-quarters of HCWs never decontaminated their phones, and 47% reported using the phones in the ICU >5 times while working. EC was frequent across samplings and sites and was substantially higher in subjects with longer follow-up. Potential risk factors identified did not have strong associations with positive samples (relative risk, 0.7-1.5), regardless of significance. Half of the phones were colonized with an Enterobacteriaceae at least once during the 4 samplings attained on average during the study period. Half of the isolates were multidrug resistant (MDR), and 33% were extended-spectrum β-lactamase producers. EC on HCWs' phones was frequent and apparently randomly distributed through the hospitals without clear clustering or strongly associated risk factors for having a positive sample. Based on the level of EC, phones may be considered as potential bacterial reservoirs of MDR and ESBL bacteria.

Prevalence and characterization of extended-spectrum beta-lactamase-producing Enterobacteriaceae in spring waters.

The purpose of this study was to investigate the prevalence and characterization of extended-spectrum beta-lactamases (ESBL)-producing Enterobacteriaceae from spring waters in Mountain Tai of China. ESBL-producing Enterobacteriaceae were found in four out of 50 sampled spring waters (4/50, 8·0%) and a total of 16 non-duplicate ESBL-producing Enterobacteriaceae were obtained, including 13 Escherichia coli (E. coli) and three Klebsiella pneumoniae (Kl. pneumoniae). All 16 nonduplicate ESBL-producing Enterobacteriaceae isolates harboured genes encoding CTX-M ESBLs, among which six expressed CTX-M-15, five produced CTX-M-14, three produced CTX-M-55 and two expressed CTX-M-27. Four multilocus sequence types (ST) were found and ST131 was the dominant type (8/16, 50·0%). Taken together, the contamination of ESBL-producing Enterobacteriaceae were present in spring waters of Mountain Tai. The results indicated that spring waters could become a reservoir of antibiotic resistant bacteria and contribute to the spread of antimicrobial-resistant bacteria via drinking water or food chain. In addition, wastewater discharge of restaurants or hotels may be an important contribution source of antibiotic resistant bacteria in spring waters.

Multidrug resistance found in extended-spectrum beta-lactamase-producing Enterobacteriaceae from rural water reservoirs in Guantao, China.

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae have been isolated from humans and animals across the world. However, data on prevalence of ESBL-producing Enterobacteriaceae from rural water reservoirs is limited. This study aimed to isolate and characterize ESBL-producing Enterobacteriaceae in rural water reservoirs in Guantao, China. ESBL-producing Enterobacteriaceae were found in 5 (16.7%) of 30 sampled rural water reservoirs. Sixty-six individual isolates expressing an ESBL phenotype were obtained in the present study. Species identification showed that 42 representatives of Escherichia coli, 17 Klebsiella pneumoniae, 4 Raoultella planticola, and 3 Enterobacter cloacae. Twenty isolates contained a single bla gene, including CTX-M (17 strains), TEM (2 strains), and SHV (1 strain). Forty-six isolates contained more than one type of beta-lactamase genes. ESBL-producing Enterobacteriaceae isolated in this study were all multidrug resistant. These findings indicated that the serious contamination of ESBL-producing Enterobacteriaceae in rural water reservoirs existed in Guantao, China.

Selection of Informative Spectral Wavelength for Evaluating and Visualising Enterobacteriaceae Contamination of Salmon Flesh

Enterobacteriaceae is one kind of harmful microorganisms commonly presented in raw fish products, and detection of Enterobacteriaceae plays a very important role in evaluating microbial contamination. This work was carried out to exploit the potential of emerging hyperspectral imaging technique to determine the Enterobacteriaceae contamination of salmon flesh during cold storage. The spectral information ranging from 900 to 1700 nm (239 wavelengths) was extracted to relate to the Enterobacteriaceae loads (recorded as log 10 CFU/g) using partial least square (PLS) regression, developing a PLS model with correlation coefficient of prediction (rP) of 0.94 and root mean square error of prediction (RMSEP) of 0.53 as well as residual predictive deviation (RPD) of 2.97. By applying successive projection algorithm (SPA), eight wavelengths at 924, 931, 964, 1068, 1262, 1373, 1628 and 1668 nm among the 239 wavelengths were selected as informative wavelengths to reduce the information redundancy and optimise the PLS model. With the eight informative wavelengths, a simplified PLS model defined as SPA-PLS was established with rP of 0.95, RMSEP of 0.47 and RPD of 3.23. To visualise the contamination degree of salmon flesh caused by Enterobacteriaceae, the SPA-PLS model was transferred to each pixel of images, and colourful distribution maps were produced with different colour represented different numbers of Enterobacteriaceae colonies. The results showed that hyperspectral imaging operating in 900–1700 nm is promising in evaluating Enterobacteriaceae contamination of salmon products. More studies are still required to further refine the multispectral imaging system to achieve online application.

Enterobacteriaceae contamination in chocolate processing

A survey was conducted on two Brazilian chocolate manufacturing companies (A and B) to investigate/determine Enterobacteriaceae, coliforms and Salmonella contamination. Samples of different chocolate types, processed cocoa-based ingredients, manufacturing environment, and workers' hand surfaces were analyzed. Salmonella and Escherichia coli were not detected. However, in 25.8% of the chocolate samples, Enterobacteriaceae were isolated while total coliforms were detected in 13.3%. Among the processed cocoa-based ingredients, two samples of cocoa liquor showed contamination by Enterobacteriaceae and total coliforms, and in one sample thermotolerant coliforms were also recovered. For equipment and utensils, Enterobacteriaceae were isolated in around 25.4% of the samples, whereas total coliforms were detected in 10.2%. Moreover, in company A 14.3% of manufacturing environment samples were contaminated by thermotolerant coliforms. The food handlers from both companies showed a high percentage of Enterobacteriaceae contamination on their hands. The results showed that the manufacturing environment including food handlers was considered the most likely Enterobacteriaceae contamination source of the finished product. These data also highlight Enterobacteriaceae as a good hygiene indicator for the chocolate industry.

Extended-Spectrum β-Lactamase–Producing Enterobacteriaceae in Hospital Food: A Risk Assessment

Determine the prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-PE) contamination of food and colonization of food handlers in a hospital kitchen and compare retrieved ESBL-PE strains with patient isolates. Cross-sectional study. A 2,200-bed tertiary care university hospital in Switzerland. Food handlers. Raw and prepared food samples were obtained from the hospital kitchen, with a comparator group from local supermarkets. Fecal samples collected from food handlers and selectively pre-enriched homogenized food samples were inoculated onto selective chromogenic media. Phenotypic confirmation of ESBL production was performed using the double disk method. Representative ESBL-PE were characterized using polymerase chain reaction (PCR) and sequencing for blaCTX-M, blaSHV, and blaTEM genes, and Escherichia coli strains were typed using phylotyping, repetitive element palindromic PCR, and multilocus sequence typing. Meat samples were screened for antibiotic residues using liquid chromatography time-of-flight mass spectrometry. Sixty (92%) of the raw chicken samples were ESBL-PE positive, including 30 (86%) of the hospital samples and all supermarket samples. No egg, beef, rabbit, or cooked chicken samples were ESBL-PE positive. No antibiotic residues were detected. Six (6.5%) of 93 food handlers were ESBL-PE carriers. ESBL-PE strains from chicken meat more commonly possessed blaCTX-M-1 and blaCTX-M-2, whereas blaCTX-M-14 and blaCTX-M-15 were predominant among strains of human origin. There was partial overlap in the sequence type of E. coli strains of chicken and human origin. No E. coli ST131 strains or blaCTX-M-15 genes were isolated from meat. Although there is significant ESBL-PE contamination of delivered chicken meat, current preventive strategies minimize risks to food handlers, hospital staff, and patients.

Hygienic and sensory quality factors affecting the shelf-life of Fruhe (Casu axedu) traditional Sardinian fresh cheese

A study was conducted to evaluate the dura- bility of the traditional fresh soft cheese Fruhe manufactured in Sardinia either from goats’ or sheep’s milk. Four farmstead cheese-making plants were visited three times during the Fruhe cheese-making season. During each visit environmental samples were collected from food contact and non-food contact sur- faces in order to evaluate the presence of Enterobacteriaceae , Escherichia coli , Pseudomonas spp. and Listeria spp. In a total of 60 environmental samples, Escherichia coli and Listeria spp. were never detected, while contamination with Enterobacteriaceae and Pseudomonas spp. was observed respectively in 48% and 43% of samples. The microbiological profile of 48 Fruhe cheese samples was assessed at different time points during the product shelf-life. Aerobic mesophilic bacteria, Enterobacteriaceae , E. coli , Pseudomonas spp., Bacillus cereus and Listeria monocytogenes were investigated at 0, 7, 14 and 21 days after production. E. coli , L. monocytogenes and B. cereus were never detected in the product. Enterobacteriaceae contamination was observed, showing decreasing levels over time. Pseudomonas spp. was recovered in only two Fruhe samples (3.3%) at day 0. Sensory analysis was also conducted using a triangle test to determine whether a difference between Fruhe samples at 14 and 21 days of shelf-life exists. Based on the evolution of the microbiological profile and the sensory attributes observed in the present study, it is reasonable to assume that the product shelf-life can be feasibly extended up to 21 days.

Bacteriological investigation of microorganisms (Salmonella sp. and other Enterobacteriaceae) in common quails (Coturnix coturnix) submitted to different forced-molting procedures

The aim of this study was to investigate the presence of Salmonella in common quails submitted to forced molting. A total of 240 quails were divided at 40 weeks of age into four groups: CG (control, quails not submitted to molting); FM (fasting method); WM (fed wheat midds ad libitum); and ZM (zinc oxide method). From each group, 10 cloacal swabs, 10 fecal samples, and 20 egg samples were collected before molting (two weeks) and after molting (two weeks). The microbiological procedures for Salmonella spp. identification were performed in four steps. The agglutination test, using somatic and flagellar antigens, was used to confirm Salmonella-suspected colonies. According to the methodology applied, none of the samples was positive for Salmonella spp. The results showed that 20.0% of the egg samples from birds submitted to forced molting were contaminated with enterobacteria. It was concluded that, under the conditions of the present experiment, the stress caused by forced molting did not induce infection by Salmonella spp. or increased Enterobacteriaceae contamination levels in the eggs.