Category Archives: Antibiotic Resistance

Research – Occurrence, Antibiotic Resistance and Biofilm-Forming Ability of Listeria monocytogenes in Chicken Carcasses and Cuts

Posted on December 6, 2024 by | Leave a comment

MDPI

A total of 104 samples of chicken meat acquired on the day of slaughter from two slaughterhouses in northwestern Spain were analyzed. These comprised 26 carcasses and 26 cuts from each of the two establishments. An average load of 5.39 ± 0.61 log10 cfu/g (total aerobic counts) and 4.90 ± 0.40 log10 cfu/g (psychrotrophic microorganisms) were obtained, with differences (p < 0.05) between types of samples and between slaughterhouses. Culturing methods involving isolation based on the UNE-EN-ISO 11290-1:2018 norm and identification of isolates by polymerase chain reaction (PCR) to detect the lmo1030 gene allowed the detection of Listeria monocytogenes in 75 samples (72.1% of the total; 50.0% of the carcasses and 94.2% of the cuts). The 75 isolates, one for each positive sample, were tested for resistance against a panel of 15 antibiotics of clinical interest by the disc diffusion method. All isolates belonged to the serogroup IIa (multiplex PCR assay) and showed resistance to between four and ten antibiotics, with an average value of 5.7 ± 2.0 resistances per isolate, this rising to 7.0 ± 2.1 when strains with resistance and reduced susceptibility were taken together. A high prevalence of resistance was observed for antibiotics belonging to the cephalosporin and quinolone families. However, the level of resistance was low for antibiotics commonly used to treat listeriosis (e.g., ampicillin or gentamicin). Nine different resistance patterns were noted. One isolate with each resistance pattern was tested for its ability to form biofilms on polystyrene during 72 h at 12 °C. The total biovolume of the biofilms registered through confocal laser scanning microscopy (CLSM) in the observation field of 16,078.24 μm2 ranged between 13,967.7 ± 9065.0 μm3 and 33,478.0 ± 23,874.1 μm3, and the biovolume of inactivated bacteria between 0.5 ± 0.4 μm3 and 179.1 ± 327.6 μm3. A direct relationship between the level of resistance to antibiotics and the ability of L. monocytogenes strains to form biofilms is suggested.

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Posted in Antibiotic Resistance, antimicrobial resistance, Biofilm, Food Microbiology Research, Listeria, Listeria monocytogenes, PCR, Research

Research – UK food microbiology lab reports updates on recent work

Posted on November 2, 2024 by | Leave a comment

Food Safety News

The main food microbiology lab in the United Kingdom has shared highlights of its recent activity in an annual report.

The report covers work of the UK’s national reference laboratory (NRL) for food microbiology between April 2023 and March 2024.

The UK Health Security Agency (UKHSA) provides the service for the Food Standards Agency (FSA) and Food Standards Scotland (FSS). It covers Listeria monocytogenes, coagulase-positive staphylococci, E. coli, Campylobacter, Salmonella, and antimicrobial resistance.

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Posted in Antibiotic Resistance, antimicrobial resistance, Antimicrobials, Campylobacter, E.coli, Listeria, Listeria monocytogenes, Salmonella, Staphylococcus aureus, UKHSA, UKSHA

Research – Microbiological Quality and Antibiotic Resistance of Relevant Bacteria from Horsemeat

Posted on August 31, 2024 by | Leave a comment

MDPI

Abstract

The aim of this work was to assess the microbiological safety and quality of horsemeat. A total of 19 fresh horsemeat samples were analysed. Mesophile counts were 4.89 ± 1.08 log CFU/g, and Enterobacteriaceae, Staphylococcus spp., and enterococci were only isolated from 36.84%, 21.05%, and 15.79% of the samples, respectively. Neither Staphylococcus aureus nor Escherichia coli were found in any sample. Listeria spp. and Listeria monocytogenes were detected in 31.58% and 21.05% of the samples, respectively. Campylobacter jejuni was not detected in any sample. The dominant bacteria were lactic acid bacteria. Seven different Staphylococcus spp. were identified, the most common being S. delphini, S. saprophyticus, and S. warneri. S. delphini showed resistance against mupirocin and cefoxitin. All the L. monocytogenes strains showed resistance against ampicillin, cefotaxime, and oxacillin. Multi-resistant Yersinia enterocolitica, Stenotrophomonas maltophilia, and Vagococcus. fluvialis strains were found, with resistance to 11, 7, and 8 antibiotics, respectively, causing significant concern. Therefore, specific actions should be taken to decrease the contamination of horsemeat.

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Posted in Antibiotic Resistance, Campylobacter, Campylobacter jejuni, E.coli, Enterobacteriaceae, Enterococcus, Food Microbiology Research, Research, Staphylococcus aureus

Research – Survival of Salmonella spp., Escherichia coli O157:H7, and Listeria monocytogenes in Ready-to-Eat “Guacamole”: Role of Added Antimicrobials

Posted on July 20, 2024 by | Leave a comment

MDPI

Abstract

Ensuring the microbiological safety of food products is majorly important to regulatory agencies, producers, and consumers. This study aimed to examine the effects of three different antimicrobial agents, including chitosan (CH), mastic oil (M), and citric acid (CA), individually or as a combination, against Salmonella spp., Escherichia coli O157:H7, and Listeria monocytogenes (artificially inoculated) in Guacamole, a ready-to-eat (RTE) avocado-based salad. The Guacamole samples included untreated samples, designated as CNL, and samples treated as follows: CA 0.15% and CA 0.30% with citric acid added at 0.15% and 0.30% v/w; CH 0.5% and CH 1% with chitosan at 0.5 and 1% v/w; M 0.2% and M 0.4% with mastic essential oil (EO) at 0.2% and 0.4% v/w; CACH with CA 0.30% and CH 1% v/w; CAM with CA 0.30% and M 0.4% v/w; CHM with CH 1% and M 0.4% v/w; and CACHM with CA 0.30%, CH 1%, and M 0.4% v/w. Microbiological evaluation, monitoring of the pH values, and proximate analyses (moisture, fat, protein, ash, and water activity) were performed at different time intervals (days 0, 1, 3, 5, and 7) at two storage temperatures (4 and 10 °C). Antimicrobial treatments, particularly CH 1% and CACHM, effectively (p < 0.05) reduced Salmonella spp. and E. coli O157:H7 populations at 4 °C, while CACHM showed the most efficacy against L. monocytogenes. However, at 10 °C, antimicrobials had limited impact, and the bacterial counts exhibited an increasing trend during storage. The pH values in the avocado-based salad samples showed, in general, higher decreases at 10 compared to 4 °C, with the CHM combination showing the highest antimicrobial effect.

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Posted in Antibiotic Resistance, E.coli O157, E.coli O157:H7, Food Microbiology Research, Food Safety Alert, Food Safety Management, Food Safety Regulations, Listeria, Listeria monocytogenes, Research, Salmonella

Research – Antibiotic Resistant Escherichia coli in Uncooked Meat Purchased from Large Chain Grocery Stores and in Raw Dog Food Purchased From Pet Stores in the Same City

Posted on May 6, 2024 by | Leave a comment

BIORXIV

Abstract

Although previous studies have associated feeding dogs uncooked meat with their carriage and excretion of antibiotic resistant (ABR) Escherichia coli, this practice remains popular amongst dog owners in some countries, including the UK. Uncooked meat fed to dogs is purchased from stores selling meat primarily for human consumption, or it is a brand of commercial raw dog food (RDF), which is commonly sold frozen and thawed prior to feeding. We tested 58 packets of uncooked meat (beef, chicken, lamb and pork) purchased from large chain grocery stores (15 stores) and 15 packets of thawed, chicken-based RDF (11 brands) for the presence of ABR E. coli. All samples were purchased from the city of Bristol, UK. Among grocery store-purchased meat, chicken samples were significantly more likely to be positive for E. coli resistant to amoxicillin, spectinomycin, streptomycin, and the critically important antibiotics cefotaxime and ciprofloxacin, than other types of meat. When comparing grocery store chicken to chicken-based RDF we found no significant difference in sample-level positivity for resistant E. coli, which, for RDF was 80% (amoxicillin), 80% (spectinomycin), 87% (streptomycin), 27% (amoxicillin-clavulanate), 27% (cefotaxime) and 47% (ciprofloxacin). We conclude that despite it having been purchased frozen and thawed prior to testing according to the manufacturer’s instructions, contamination of RDF with ABR E. coli is similar to that of uncooked meat primarily intended for human consumption after cooking, and so the same strict hygiene practices are advised when handling RDF as uncooked meat. Our findings provide a rationale to explain why feeding uncooked meat or RDF to dogs in the city of Bristol is associated with them excreting E. coli resistant to critically important antibiotics.

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Posted in Animal Feed Recall, Animal Feed Salmonella, Animal Feed Testing, Antibiotic Resistance, E.coli, Pet Food, Pet Food Illness, Pet Food Recall, Pet Food Salmonella, Pet Food Testing, raw pet food

Research – Multistate nontyphoidal Salmonella and Shiga toxin-producing Escherichia coli outbreaks linked to international travel—United States, 2017–2020

Posted on February 9, 2024 by | Leave a comment

Cambridge.org

Abstract

Enteric bacterial infections are common among people who travel internationally. During 2017–2020, the Centers for Disease Control and Prevention investigated 41 multistate outbreaks of nontyphoidal Salmonella and Shiga toxin-producing Escherichia coli linked to international travel. Resistance to one or more antimicrobial agents was detected in at least 10% of isolates in 16 of 30 (53%) nontyphoidal Salmonella outbreaks and 8 of 11 (73%) Shiga toxin-producing E. coli outbreaks evaluated by the National Antimicrobial Resistance Monitoring System. At least 10% of the isolates in 14 nontyphoidal Salmonella outbreaks conferred resistance to one or more of the clinically significant antimicrobials used in human medicine. This report describes the epidemiology and antimicrobial resistance patterns of these travel-associated multistate outbreaks. Investigating illnesses among returned travellers and collaboration with international partners could result in the implementation of public health interventions to improve hygiene practices and food safety standards and to prevent illness and spread of multidrug-resistant organisms domestically and internationally.

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Posted in Antibiotic Resistance, antimicrobial resistance, Antimicrobials, CDC, food bourne outbreak, Food Microbiology Research, foodborne outbreak, foodbourne outbreak, outbreak, Research, Salmonella

EU – Zoonoses, foodborne outbreaks and antimicrobial resistance guidance for reporting 2023 data

Posted on January 29, 2024 by | Leave a comment

EFSA

This technical report provides guidance for reporting countries on how to submit their isolate-based quantitative antimicrobial resistance data, and data on the prevalence of zoonoses and microbiological agents and contaminants in food, food-borne outbreaks, animal populations and disease status. To collect these data, EFSA has created the Data Collection Framework (DCF) application. This report includes data dictionaries to guide the reporting of information derived from 2023 under Directive 2003/99/EC, Regulation (EU) 2017/625, Commission Implementing Regulation (EU) 2019/627 and Commission Implementing Decision (EU) 2020/1729. The objective is to explain in detail the individual data elements of the EFSA data models that are to be used for XML data submission through the DCF. In particular, it explains the data elements to be reported, including information about the data type, a reference to the list of permitted terms and any additional business rules or requirements that may apply.

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Posted in AMR, Antibiotic Resistance, antimicrobial resistance, food bourne outbreak, Food Microbiology Research, foodborne outbreak, foodbourne outbreak, outbreak, Research, Zoonosis

Research – Salmonella in horses at slaughter and public health effects in Italy

Posted on January 14, 2024 by | Leave a comment

Science Direct

Abstract

The study assessed the role of equids at slaughter as faecal carriers of Salmonella enterica and the occurrence of contaminated equid carcasses during the slaughter process in Northern Italy (Emilia-Romagna Region). From June to November 2021, 152 equids (146 horses, 5 donkeys and 1 mule) were tested for Salmonella both in caecal contents and through carcass swabs. Antimicrobial resistance (AMR) of recovered strains was tested against 15 antimicrobials. Salmonella was detected in 3/152 of the caecal contents (2.0 %), while all carcass samples were negative. S. enterica serovars Enteriditis, Typhimurium and Stanleyville were identified. The only AMR isolate was S. Typhimurium with AMR profile AmCStxT.

Considering the consumption of raw horse meat (i.e., minced raw meat named “pesto di cavallo” and dried and smoked strips named “sfilacci di cavallo”) in different areas of Northern Italy, we also investigated the possible link between horse meat eating and salmonellosis cases in the human population in the same area. Specifically, we compared the Salmonella strains collected during the study with those routinely processed in the laboratory surveillance system for human salmonellosis in Emilia-Romagna (a region with about 4.5 million inhabitants). The comparison was based on whole genome sequencing data through core genome multi-locus sequence typing (cgMLST) used in routine surveillance. A genomic match in cgMLST was found between the strain of S. enterica serovar Enteritidis isolated from a horse caecal content and an enduring outbreak of 17 human cases in Emilia-Romagna during the study period. The consequent epidemiological investigation highlighted that a number of cases with known food history reported the consumption of horse meat and traced different batches of the consumed meat, released weeks apart from each other, to the slaughter investigated in the study. The results of the epidemiological investigation suggested the role of horses in the S. enterica serovar Enteritidis outbreak affecting raw horse meat consumers.

This study shows that, despite the low prevalence on equid carcasses, S. enterica in horse meat can represent a risk to consumers. From the perspective of the slaughter activities, this highlights the need to maintain a high level of hygiene during the entire process, starting from the hygiene at lairage up to the slaughtering phase and dressing of carcasses.

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Posted in Antibacterial, Antibiotic Resistance, antimicrobial resistance, food bourne outbreak, foodborne outbreak, foodbourne outbreak, MLST, outbreak, Salmonella, WGS, Whole Genomic Sequencing

Research – Predictive Mapping of Antimicrobial Resistance for Escherichia coli, Salmonella, and Campylobacter in Food-Producing Animals, Europe, 2000–2021

Posted on December 30, 2023 by | Leave a comment

cdc

Abstract

In Europe, systematic national surveillance of antimicrobial resistance (AMR) in food-producing animals has been conducted for decades; however, geographic distribution within countries remains unknown. To determine distribution within Europe, we combined 33,802 country-level AMR prevalence estimates with 2,849 local AMR prevalence estimates from 209 point prevalence surveys across 31 countries. We produced geospatial models of AMR prevalence in Escherichia coli, nontyphoidal Salmonella, and Campylobacter for cattle, pigs, and poultry. We summarized AMR trends by using the proportion of tested antimicrobial compounds with resistance >50% and generated predictive maps at 10 × 10 km resolution that disaggregated AMR prevalence. For E. coli, predicted prevalence rates were highest in southern Romania and southern/eastern Italy; for Salmonella, southern Hungary and central Poland; and for Campylobacter, throughout Spain. Our findings suggest that AMR distribution is heterogeneous within countries and that surveillance data from below the country level could help with prioritizing resources to reduce AMR.

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Posted in Antibacterial, Antibiotic Resistance, antifungal, antimicrobial resistance, Antimicrobials, Campylobacter, E.coli, Food Microbiology Research, Multi Drug Resistant, Research, Salmonella

Research – Sweet and sour synergy: exploring the antibacterial and antibiofilm activity of acetic acid and vinegar combined with medical-grade honeys

Posted on December 5, 2023 by | Leave a comment

Microbiology Society

ABSTRACT

, a combination of honey and vinegar, has been used as a remedy for wounds and infections in historical and traditional medical settings. While honey is now clinically used to treat infected wounds, this use of a complex, raw natural product (NP) mixture is unusual in modern western medicine. Research into the antimicrobial activity of NPs more usually focuses on finding a single active compound. The acetic acid in vinegar is known to have antibacterial activity at low concentrations and is in clinical use to treat burn wound infections. Here, we investigated the potential for synergistic activity of different compounds present in a complex ingredient used in historical medicine (vinegar) and in an ingredient mixture (). We conducted a systematic review to investigate published evidence for antimicrobial effects of vinegars against human pathogenic bacteria and fungi. No published studies have explicitly compared the activity of vinegar with that of a comparable concentration of acetic acid. We then characterized selected vinegars by HPLC and assessed the antibacterial and antibiofilm activity of the vinegars and acetic acid, alone and in combination with medical-grade honeys, against and . We found that some vinegars have antibacterial activity that exceeds that predicted by their acetic acid content alone, but that this depends on the bacterial species being investigated and the growth conditions (media type, planktonic vs. biofilm). Pomegranate vinegars may be particularly interesting candidates for further study. We also conclude that there is potential for acetic acid, and some vinegars, to show synergistic antibiofilm activity with manuka honey.

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Posted in Antibiotic Resistance, antimicrobial resistance, Antimicrobials, Biofilm, Food Microbiology Research, Pseudomonas aeruginosa, Research, Staphylococcal Toxin