Category Archives: Enterococcus

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 – Efficacy of organic acids, lactic and formic acid, and peracetic acid in decontaminating process water and carcasses in chicken slaughter

Posted on August 23, 2024 by | Leave a comment

Wiley Online

Abstract

Foodborne pathogens pose a persistent threat in broiler chicken production, particularly during the slaughter process, where contamination with zoonotic pathogens remains a concern. This study focuses on the potential of organic acids, such as formic and lactic acid, and the oxidizing agent peracetic acid, to decontaminate scalding water and enhance the hygiene of chicken carcasses. We conducted suspension tests introducing various organic loads to mirror the conditions of practical scalding water. Additionally, the surface tests were performed on chicken skin. Both methods were further tested in an experimental slaughtering facility. In suspension tests, the organic acids achieved impressive decontamination, with a 5-log10 reduction of the test organisms Enterococcus hirae, Salmonella Typhimurium and Campylobacter jejuni at minimal concentrations (between 0.04% and 2% for formic acid; between 0.1% and 4.5% for lactic acid). Peracetic acid also effectively sanitized model water and chicken skin, even when used in low concentrations (between 0.001% and 0.1%), both in the laboratory-based testing and in the experimental slaughtering facility. These results suggest that the tested disinfectants can effectively sanitize process water, even under conditions mimicking practical scalding water with organic matter. Peracetic acid, in particular, proved highly effective in improving chicken skin hygiene even at low concentrations.

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Posted in Bio-Preservative, Campylobacter, Enterococcus, Food Microbiology Research, Food Pathogen, Food Technology, Hurdle Technology, Pathogen, pathogenic, Research, Salmonella, Zoonosis

Research – Fully automated E. coli and Enterococci monitoring

Posted on May 26, 2024 by | Leave a comment

Envirotech

Rather than enduring the tedious procedure associated with the microbiological procedure in which bacteria colonies are left to grow and are then counted, the ColiMinder technology, which is sold and marketed in the UK by QCL (QuadraChem Laboratories Ltd), operates by taking a direct measurement of the sampled target organisms’ specific metabolic activity. ColiMinder provides fully automated, real-time microbiological measurements thereby offering users a continuous overview of water quality, therefore enabling quick and decisive reactions to contamination events. The live measurement data is highlighted on a dedicated website and users receive automatic notifications via SMS and email.

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Posted in E.coli, Enterococcus, Food Microbiology Research, Food Technology, Research, Technology

Research – Diversity of Faecal Indicator Enterococci among Different Hosts: Importance to Water Contamination Source Tracking

Posted on December 23, 2023 by | Leave a comment

MDPI

Abstract

Enterococcus spp. are common bacteria present in the intestinal tracts of animals and are used as fecal indicators in aquatic environments. On the other hand, enterococci are also known as opportunistic pathogens. Elucidating their composition in the intestinal tracts of domestic animals can assist in estimating the sources of fecal contamination in aquatic environments. However, information on the species and composition of enterococci in animal hosts (except humans) is still lacking. In this study, enterococci were isolated from the feces of cattle, pigs, birds, and humans using selective media. Enterococcal species were identified using mass spectrometry technology, and each host was characterized by diversity and cluster analysis. The most dominant species were E. hirae in cattle, E. faecium in birds, and E. faecalis in pigs and humans. Cattle had the highest alpha diversity, with high interindividual and livestock farm diversity. The dominant enterococcal species in pigs and humans were identical, and cluster analysis showed that the majority of the two hosts’ species clustered together.

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Posted in Boil Water Notice, Contaminated water, Enterococcus, Enterococcus faecalis, Enterococcus faecium, Water, water microbiology, Water Safety

Ireland – Kildare café closed due to evidence of E coli in the drinking water

Posted on November 13, 2023 by | Leave a comment

The Independent

A closure order was issued on October 26 as the drinking water supply was found to pose “grave and immediate danger to public health”

A Kildare café was among five businesses around Ireland that were served with closure orders by the Food Safety Authority in October.

Base Coffee, at The Mart, on Newbridge Road in Kilcullen, County Kildare, was served the order on October 26, after the FSAI inspectors had “concerns of grave and immediate danger to public health.”

The reasons for closure as stated in the FSAI food hygiene inspection report was that “a drinking water sample taken on October 24 2023 from the food business indicated that the supply [was] contaminated.”

According to the inspection report: “Coliforms, Enterococci and E coli were detected in the drinking water sample. Given these levels of contamination, the drinking water supply pose a grave and immediate danger to public health.”

Other premises which were closed in October included: Indian Spices (restaurant/café), 138 Parnell Street, Dublin 1; Mizzoni Pizza (takeaway), 12 Railway Street, Navan, Meath; Seasons Chinese, Bridge Street, Strokestown, Roscommon.

Meanwhile, one Prohibition Order was served under the Eurpoean Union (Official Controls in Relation to Food Legislation) Regulations 2020 on: Meghans Café, 8 Cecilia Street, Dublin 2.

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Posted in Coliforms, Contaminated water, E.coli, Enterococcus, Water, water microbiology, Water Safety

Research – Killing of a Multispecies Biofilm Using Gram-Negative and Gram-Positive Targeted Antibiotic Released from High Purity Calcium Sulfate Beads

Posted on September 17, 2023 by | Leave a comment

MDPI

Abstract

Background: Multispecies biofilm orthopedic infections are more challenging to treat than mono-species infections. In this in-vitro study, we aimed to determine if a multispecies biofilm, consisting of Gram positive and negative species with different antibiotic susceptibilities could be treated more effectively using high purity antibiotic-loaded calcium sulfate beads (HP-ALCSB) containing vancomycin (VAN) and tobramycin (TOB) in combination than alone. Methods: Three sets of species pairs from bioluminescent strains of Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA) and clinical isolates, Enterococcus faecalis (EF) and Enterobacter cloacae were screened for compatibility. PA + EF developed intermixed biofilms with similar cell concentrations and so were grown on 316L stainless steel coupons for 72 h or as 24 h agar lawn biofilms and then treated with HP-ALCSBs with single or combination antibiotics and assessed by viable count or bioluminescence and light imaging to distinguish each species. Replica plating was used to assess viability. Results: The VAN + TOB bead significantly reduced the PA + EF biofilm CFU and reduced the concentration of surviving antibiotic tolerant variants by 50% compared to single antibiotics. Conclusions: The combination of Gram-negative and positive targeted antibiotics released from HP-ALCSBs may be more effective in treating multispecies biofilms than monotherapy alone.

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Posted in Biofilm, Decontamination Microbial, Enterococcus, Enterococcus faecalis, Enterococcus faecium, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Pseudomonas, Pseudomonas aeruginosa, Staphylococcus aureus

Research – Microbial Spoilage of Traditional Goose Sausages Produced in a Northern Region of Italy

Posted on August 5, 2023 by | Leave a comment

MDPI

Abstract

Recently, during the ripening of goose sausage, a defect consisting of ammonia and vinegar smell was noticed. The producer of the craft facility, located in Lombardia, a Northern region of Italy, asked us to identify the cause of that defect. Therefore, this study aimed to identify the potential responsible agents for the spoilage of this lot of goose sausages. Spoilage was first detected by sensory analysis using the “needle probing” technique; however, the spoiled sausages were not marketable due to the high ammonia and vinegar smell. The added starter culture did not limit or inhibit the spoilage microorganisms, which were represented by Levilactobacillus brevis, the predominant species, and by Enterococcus faecalis and E. faecium. These microorganisms grew during ripening and produced a large amount of biogenic amines, which could represent a risk for consumers. Furthermore, Lev. brevis, being a heterofermentative lactic acid bacteria (LAB), also produced ethanol, acetic acid, and a variation in the sausage colour. The production of biogenic amines was confirmed in vitro. Furthermore, as observed in a previous study, the second cause of spoilage can be attributed to moulds which grew during ripening; both the isolated strains, Penicillium nalgiovense, added as a starter culture, and P. lanosocoeruleum, present as an environmental contaminant, grew between the meat and casing, producing a large amount of total volatile nitrogen, responsible for the ammonia smell perceived in the ripening area and in the sausages. This is the first description of Levilactobacillus brevis predominance in spoiled goose sausage.

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Posted in Enterococcus, Enterococcus faecalis, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Testing, Food Spoilage, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Pseudomonas

Research – Microbiological Quality and Safety of Fresh Turkey Meat at Retail Level, Including the Presence of ESBL-Producing Enterobacteriaceae and Methicillin-Resistant S. aureus

Posted on March 19, 2023 by | Leave a comment

MDPI

Abstract

The aim of this work was to study the microbiological safety and quality of marketed fresh turkey meat, with special emphasis on methicillin-resistant S. aureus, ESBL-producing E. coli, and K. pneumoniae. A total of 51 fresh turkey meat samples were collected at retail level in Spain. Mesophile, Pseudomonas spp., enterococci, Enterobacteriaceae, and staphylococci counts were 5.10 ± 1.36, 3.17 ± 0.87, 2.03 ± 0.58, 3.18 ± 1.00, and 2.52 ± 0.96 log CFU/g, respectively. Neither Campylobacter spp. nor Clostridium perfringens was detected in any sample. ESBL-producing K. pneumoniae and E. coli were detected in 22 (43.14%), and three (5.88%) samples, respectively, all of which were multi-resistant. Resistance to antimicrobials of category A (monobactams, and glycilcyclines) and category B (cephalosporins of third or fourth generation, polymixins, and quinolones), according to the European Medicine Agency classification, was found among the Enterobacteriaceae isolates. S. aureus and methicillin-resistant S. aureus were detected in nine (17.65%) and four samples (7.84%), respectively. Resistance to antimicrobials of category A (mupirocin, linezolid, rifampicin, and vancomycin) and category B (cephalosporins of third- or fourth generation) was found among S. aureus, coagulase-negative staphylococci, and M. caseolyticus isolates.

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Posted in Enterococcus, ESBL, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, MRSA, Pathogen, Staphylococcal Toxin, Staphylococcus aureus

Research – Microbiological safety of aged meat

Posted on January 19, 2023 by | Leave a comment

EFSA

Abstract

The impact of dry-ageing of beef and wet-ageing of beef, pork and lamb on microbiological hazards and spoilage bacteria was examined and current practices are described. As ‘standard fresh’ and wet-aged meat use similar processes these were differentiated based on duration. In addition to a description of the different stages, data were collated on key parameters (time, temperature, pH and aw) using a literature survey and questionnaires.

The microbiological hazards that may be present in all aged meats included Shiga toxin-producing Escherichia coli(STEC),Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, enterotoxigenic Yersinia spp., Campylobacter spp. and Clostridium spp. Moulds, such as Aspergillus spp. and Penicillium spp., may produce mycotoxins when conditions are favourable but may be prevented by ensuring a meat surface temperature of−0.5 to 3.0°C, with a relative humidity (RH) of 75–85% and an airflow of 0.2–0.5 m/s for up to 35 days.

The main meat spoilage bacteria include Pseudomonas spp., Lactobacillus spp. Enterococcus spp., Weissella spp., Brochothrix spp., Leuconostoc spp. Lactobacillus spp., Shewanella spp. and Clostridium spp. Undercurrent practices, the ageing of meat may have an impact on the load of microbiological hazards and spoilage bacteria as compared to standard fresh meat preparation. Ageing under defined and controlled conditions can achieve the same or lower loads of microbiological hazards and spoilage bacteria than the variable log10increases predicted during standard fresh meat preparation. An approach was used to establish the conditions of time and temperature that would achieve similar or lower levels of L. monocytogenes and Yersinia enterocolitica (pork only) and lactic acid bacteria(representing spoilage bacteria) as compared to standard fresh meat. Finally, additional control activities were identified that would further assure the microbial safety of dry-aged beef, based on recommended best practice and the outputs of the equivalence assessment.

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Posted in Brochothrix thermosphacta, Clostridium, Decontamination Microbial, Enterococcus, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Leuconostoc mesenteroides, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Shigatoxin, Shigella, Staphylococcus aureus, STEC, STEC E.coli

Resaerch- Evaluation of Various Lactic Acid Bacteria and Generic E. coli as Potential Non-pathogenic Surrogates for In-Plant Validation of Biltong Dried Beef Processing

Posted on August 20, 2022 by | Leave a comment

MDPI

Validation studies conducted within a food processing facility using surrogate organisms could better represent the manufacturing process than controlled laboratory studies with pathogenic bacteria on precision equipment in a BSL-2 lab. The objectives of this project were to examine potential surrogate bacteria during biltong processing, conduct biltong surrogate validation lethality studies, and measure critical factors and intrinsic parameters during processing. Beef pieces (1.9 cm × 5.1 cm × 7.6 cm) were inoculated with four-strain mixtures of Carnobacterium divergens/C. gallinarum, Pediococcus acidilactici/P. pentosaceous, and Biotype 1 E. coli ATCC BAA (-1427, -1428, -1429, and -1430), as well as a two-strain mixture of Latilactobacillus sakei and other commercially available individual bacterial cultures (P. acidilactici Saga200/Kerry Foods; Enterococcus faecium 201224-016/Vivolac Cultures). Inoculated beef was vacuum-tumbled in marinade and dried in a humidity-controlled oven for 8–10 days (24.9 °C; 55% relative humidity). Microbial enumeration of surviving surrogate bacteria and evaluation of intrinsic factors (water activity, pH, and salt concentration) were performed post inoculation, post marination, and after 2, 4, 6, 8, and 10 days of drying. Trials were performed in duplicate replication with triplicate samples per sampling time and analyzed by one-way RM-ANOVA. Trials conducted with E. faecium, Pediococcus spp., and L. sakei never demonstrated more than 2 log reduction during the biltong process. However, Carnobacterium achieved a >5 log (5.85 log) reduction over a drying period of 8 days and aligned with the reductions observed in previous trials with pathogenic bacteria (Salmonella, E. coli O157:H7, L. monocytogenes, and S. aureus) in biltong validation studies. Studies comparing resuspended freeze-dried or frozen cells vs. freshly grown cells for beef inoculation showed no significant differences during biltong processing. Carnobacterium spp. would be an effective nonpathogenic in-plant surrogate to monitor microbial safety that mimics the response of pathogenic bacteria to validate biltong processing within a manufacturer’s own facility. View Full-Text

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Posted in Decontamination Microbial, E.coli, E.coli O157, E.coli O157:H7, Enterococcus, Enterococcus faecium, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, lactic acid bacteria, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Research, Salmonella, Staphylococcus aureus