Category Archives: Antimicrobials

Research – Bacterial Attachment and Biofilm Formation on Antimicrobial Sealants and Stainless Steel Surfaces

MDPI

Biofilm of antibiotic resistant bacteria

Biofilms are highly resistant to external forces, especially chemicals. Hence, alternative control strategies, like antimicrobial substances, are forced. Antimicrobial surfaces can inhibit and reduce microbial adhesion to surfaces, preventing biofilm formation. Thus, this research aimed to investigate the bacterial attachment and biofilm formation on different sealants and stainless steel (SS) surfaces with or without antimicrobials on two Gram-positive biofilm forming bacterial strains. Antimicrobial surfaces were either incorporated or coated with anti-microbial, -fungal or/and bactericidal agents. Attachment (after 3 h) and early-stage biofilm formation (after 48 h) of Staphylococcus capitis (S. capitis) and Microbacterium lacticum (M. lacticum) onto different surfaces were assessed using the plate count method. In general, bacterial adhesion on sealants was lower compared to adhesion on SS, for surfaces with and without antimicrobials. Antimicrobial coatings on SS surfaces played a role in reducing early-stage biofilm formation for S. capitis, however, no effects were observed for M. lacticum. S. capitis adhesion and biofilm formation were reduced by 8% and 25%, respectively, on SS coated with an antimicrobial substance (SS_4_M), compared to the same surface without the antimicrobial coating (SS_4_control). Incorporation of both antifungicidal and bactericidal agents (S_5_FB) significantly reduced (p ≤ 0.05) early-stage biofilm formation of M. lacticum, compared to the other sealants incoportating either solely antifungal agents (S_2_F) or no active compound (S_control). Furthermore, the thickness of the coating layer correlated weakly with the antimicrobial effect. Hence, equipment manufacturers and food producers should carefully select antimicrobial surfaces as their effects on bacterial adhesion and early-stage biofilm formation depend on the active agent and bacterial species.

UK – AMR in Campylobacter in UK chicken over the last 20 years

FSA

Campylobacter kswfoodworld

The Food Standards Agency (FSA) has published a report analysing 20 years of data on antimicrobial resistance (AMR) in Campylobacter from retail chicken in the UK.

The study aimed to assess any trends during this 20-year period and provides a baseline against which to evaluate future, hoped-for reductions in AMR.

AMR is when bacteria adapt to become resistant to the killing effects of antimicrobials, such as antibiotics. This resistance subsequently makes such infections in humans more difficult to treat using drugs.  AMR can develop in any bacteria, including Campylobacter. Campylobacter is the main cause of bacterial food poisoning in the developed world and it is estimated that there are in excess of half a million cases annually in the UK.

The FSA’s Science lead in Microbiological Risk Assessment, Dr Paul Cook, said:

“While the data shows a marked increase in AMR in Campylobacter to certain antimicrobials, it is encouraging that there has been no significant increase in resistance since 2014.

“Any increase of AMR in Campylobacter is a concern and continued surveillance is essential. We will continue to carry out AMR surveillance in chicken and other meats and to monitor any long-term trends in resistance, while promoting good food hygiene practice to reduce exposure to AMR bacteria and protect consumer safety.”

Since its formation in 2000, the FSA has commissioned several UK-wide retail surveys and sampling studies that involved testing for Campylobacter in chicken. A significant proportion of the Campylobacter isolates detected were further tested to assess resistance to a range of antimicrobials.

Key findings from this report vary between the five main types of antimicrobial drugs included in the study. Resistance to quinolones (ciprofloxacin and nalidixic acid) and tetracycline was common in the most prevalent types of Campylobacter from chicken (Campylobacter jejuni and Campylobacter coli). In comparison, resistance to erythromycin and streptomycin was much rarer in the Campylobacter isolates examined.  Gentamicin resistance was very rare.

There are effective ways for consumers to reduce exposure to AMR bacteria. This includes cleaning surfaces properly, cooking food thoroughly, chilling food at the correct temperature and handling food hygienically so it doesn’t cross contaminate other foods or surfaces. For any fruit or vegetables consumed raw, make sure they are washed thoroughly or peeled as this will help to remove any visible dirt or bacterial contamination.

For more information on AMR, including an ‘FSA Explains’ video, visit our dedicated AMR webpage. The research report is available on our research pages.

Research – Fighting Foodborne Pathogens with Natural Antimicrobials

Mirage News

The food industry has now started exploring natural alternatives for preserving food to reduce the dependency on chemical preservatives, some of which are linked to obesity and metabolic syndrome. Specifically, natural antimicrobials produced by plants and microorganisms like bacteria and fungi can kill food-borne pathogens like Salmonella Typhimurium, Escherichia coliListeria monocytogenes and Clostridium botulinum and also food spoilage bacteria like Brochothrix thermosphactaLactobacillus spp., Bacillus spp. and Weissella spp., among others. Foodborne pathogens and spoilage microbes pose a serious health concern for consumers and destroy the appearance, texture and sensory characteristics of the food, affecting the food industry and consumers alike.

Research Paper Sunlight Parameters Influence the Survival and Decline of Salmonella and Escherichia coli in Water

Journal of Food Protection

The effect of variations in temperature, ultraviolet (UV) radiation, and sunlight intensity on generic Escherichia coli , E. coli O157:H7, Salmonella Newport and antibiotic resistant (ABR) variants of E. coli O157:H7 and S . Newport exposed to sunlight was evaluated. Bacterial strains suspended in sterile deionized water at a concentration of 8 log CFU/ml were exposed to sunlight on three different days for 180 min; control treatments were stored in the dark. The mean temperature of 30.08 and 26.57℃ on day 1 and 3 were significantly different (p<0.05). The UV intensity was significantly different on all three days and sunlight intensity significantly differed on day 3 (p<0.05). Bacterial population decline positively correlated with temperature, sunlight and UV intensity. Differences in bacterial population declines differed among specie, antibiotic resistance (ABR) profile and day of exposure. (p<0.05). On days 1 and 2, the populations of generic E. coli dropped below the limit of detection (1 log CFU/ml) while the % of live cells was 67% and 6.6% respectively. The artificial neural network model developed to predict bacterial survival under different environmental conditions suggested that Salmonella cells were more resistant than E. coli . The ABR strains had significantly higher viable cells after sunlight exposure (p<0.05). Sunlight exposed cells resuscitated in TSB varied in maximum population density and maximum growth rate based on bacterial species and presence of antibiotic resistance. Morphological changes such as viable but non-culturable (VBNC) state transition and filament formation was detected in sub-populations of sunlight exposed bacteria. Daily fluctuations in UV and sunlight intensity can result in significant variations in bacterial decline and recovery.

USA – Warning Letter – Swan Brothers Dairy Inc

FDA

Delivery Method:
UPS Overnight
Product:
Food & Beverages

Recipient:
Diane Williamson
President/Owner
Swan Brothers Dairy Inc

938 E 5th StreetClaremoreOK 74017United States

Issuing Office:
Office of Human and Animal Food Operations West Division 3

United States


WARNING LETTER
CMS Case # 61934

January 28, 2022

Dear Ms. Williamson:

The United States Food and Drug Administration (FDA) conducted an inspection of your ready-to-eat (RTE) cheese manufacturing facility located at, 938 E 5th Street, Claremore, Oklahoma, from July 26, 2021 through July 30, 2021. In addition to manufacturing RTE cheese products, you also produce unpasteurized and pasteurized milk. Our inspection was initiated after Oklahoma Department of Agriculture, Food and Forestry (ODAFF) was notified of a report from Missouri Department of Health and Senior Services (MDHSS) which documented that an individual was hospitalized with listeriosis after purchasing and consuming raw cow’s milk from your firm. Subsequently, you conducted a voluntary recall of your unpasteurized milk and cheese products.

During our inspection of your facility, FDA investigators found serious violations of the Current Good Manufacturing Practice, Hazard Analysis, and Risk-Based Preventive Controls for Human Food regulation (CGMP & PC rule), Title 21, Code of Federal Regulations, Part 117 (21 CFR Part 117). During this inspection, FDA collected environmental samples (i.e., swabs) from various areas in your processing facility. FDA laboratory analysis of the environmental swabs found the presence of L. monocytogenes, a human pathogen, in your facility. At the conclusion of the inspection, the FDA investigators issued your facility a Form FDA 483 (FDA-483), Inspectional Observations.

Based on FDA’s inspectional findings, we have determined that your RTE cheese products manufactured in your facility are adulterated within the meaning of section 402(a)(4) of the Federal Food, Drug, and Cosmetic Act (the Act) [21 U.S.C. § 342(a)(4)], in that they were prepared, packed or held under insanitary conditions whereby they may have been contaminated with filth or rendered injurious to health. You can find the Act and FDA regulations through links on the FDA’s home page at http://www.fda.gov.External Link Disclaimer

On August 6, 2021, you submitted a Qualified Facility Attestation for Human Food Facility. Additionally, we received your written responses on August 20, 2021, August 24, 2021, and September 11, 2021, which describe your completed and planned corrective actions. After reviewing the inspectional findings and responses you provided, we are issuing this letter to advise you of FDA’s concerns and provide detailed information describing the findings at your facility.

Research – Antimicrobial Susceptibility and Molecular Characterization of Escherichia coli Recovered from Milk and Related Samples

MDPI

There is a rising concern about illnesses resulting from milk consumption due to contamination by pathogenic microorganisms including Escherichia coli. This study examined the occurrence and antimicrobial susceptibility of E. coli isolated from cow milk and related samples. Furthermore, partial sequencing was done to ascertain the genetic relatedness and possible cross contamination among the samples. In all, 250 samples, that is, 50 each of raw milk, cow teat, milkers’ hands, milking utensils, and fecal matter of cows, were cultured for the identification of E. coli. E. coli was detected in 101/250 samples (40.4%). Milk and fecal samples recorded the highest percentages of 68.0% and 66.0%, respectively. Forty-two (42) E. coli strains examined for antimicrobial resistance showed an overall 25.5% resistance, 15.0% intermediate resistance, and 59.5% susceptibility. The isolates had a high level of resistance to teicoplanin (100.0%), but were susceptible to chloramphenicol (95.2%) and azithromycin (92.9%). The Multiple Antibiotic Resistance (MAR) index pattern ranged from 0.1 to 0.5, and 40.5% exhibited multiple drug resistance. The E. coli strains formed 11 haplotypes, and a phylogenic tree analysis showed relatedness among the isolates in other African countries. This observation is an indication of cross contamination among the milk and its related samples. View Full-Text

Research – Efficacy of 405 nm Light-Emitting Diode Illumination and Citral Used Alone and in Combination for Inactivation of Vibrio parahaemolyticus on Shrimp

MDPI

Vibrio parahaemolyticus is a widely distributed pathogen, which is frequently the lead cause of infections related to seafood consumption. The objective of the present study was to investigate the antimicrobial effect of the combination of 405 nm light-emitting diode (LED) and citral on V. parahaemolyticus. The antimicrobial effect of LED illumination and citral was evaluated on V. parahaemolyticus not only in phosphate-buffered saline (PBS) but also on shrimp. Quality changes of shrimp were determined by sensory evaluation. Changes in bacteria cell membrane morphology, cell membrane permeability, cell lipid oxidation level, and DNA degradation were examined to provide insights into the antimicrobial mechanism. The combination of LED treatments and citral had better antimicrobial effects than either treatment alone. LED combined with 0.1 mg/mL of citral effectively reduced V. parahaemolyticus from 6.5 log CFU/mL to below the detection limit in PBS. Combined treatment caused a 3.5 log reduction of the pathogen on shrimp within 20 min and a 6 log reduction within 2 h without significant changes in the sensory score. Furthermore, combined LED and citral treatment affected V. parahaemolyticus cellular morphology and outer membrane integrity. The profile of the comet assay and DNA fragmentation analysis revealed that combination treatment did not cause a breakdown of bacterial genomic DNA. In conclusion, LED may act synergistically with citral. They have the potential to be developed as novel microbial intervention strategies. View Full-Text

Research – Growth inhibition of Listeria monocytogenes in fresh white cheese by mustard oil microemulsion

Journal of Food Protection

Although essential oils (EOs) exhibit antimicrobial properties, its application is limited owing to their strong volatility and poor water solubility. Emulsification is a valid strategy for improving chemical stability. In this study, we prepared a mustard essential oil (MO) emulsion with egg yolk lecithin and evaluated its antimicrobial activity against Listeria monocytogenes in vitro and in cheese curd. The particle size of the MO emulsion was approximately 0.19 µmand remained stable for 30 days of storage. The MO emulsion showed strong antimicrobial activity against L. monocytogenes in vitro. Moreover, 40 ppm of MO was sufficient to inhibit the growth of L. monocytogenes in culture, and the addition of 160 ppm MO decreased the population of L. monocytogenes. Meanwhile, when 50 ppm of emulsified MO was added to milk during cheese curd production and it was stored at 10°C for 10 days, the growth of L. monocytogenes was suppressed. When the cheese curd with MO emulsion was stored at 4 °C, the bacterial count was significantly decreased (p<0.05), and no bacterial growth was observed after 14 days of storage. Furthermore, the sensory characteristics of cheese curd with the MO emulsion were acceptable. These results indicate that MO emulsions may be a possible way of controlling the growth of L. monocytogenes in fresh cheese.

Research – Sink survey to investigate multidrug resistance pattern of common foodborne bacteria from wholesale chicken markets in Dhaka city of Bangladesh

Nature.com

Antimicrobial resistance (AMR) among foodborne bacteria is a well-known public health problem. A sink survey was conducted to determine the AMR pattern of common foodborne bacteria in cloacal swab of broiler chickens and sewage samples from five wholesale chicken markets of Dhaka city in Bangladesh. Bacteria were identified by culture-based and molecular methods, and subjected to antimicrobial susceptibility testing. Resistance genes were identified by multiplex PCR and sequencing. Multidrug resistance (MDR) was observed in 93.2% of E. coli, 100% of Salmonella spp., and 97.2% of S. aureus from cloacal swab samples. For sewage samples, 80% of E. coli, and 100% of Salmonella and S. aureus showed MDR. Noteworthy, 8.3% of S. aureus from cloacal swab samples showed possible extensively drug resistance. Antimicrobial resistance genes (beta-lactamase—blaTEM, blaSHV; quinolone resistance gene—qnrS) were detected in a number of E. coli and Salmonella isolates from cloacal swab and sewage samples. The methicillin resistance gene (mecA) was detected in 47.2% and 25% S. aureus from cloacal swab and sewage samples, respectively. The findings envisage the potential public health risk and environmental health hazard through spillover of common foodborne MDR bacteria.

Research – New NARMS report shows rising resistance in Salmonella, Campylobacter

CIDRAP

The findings come from the National Antimicrobial Resistance Monitoring Systems (NARMS) 2019 Integrated Summary, which combines data from the Centers for Disease Control and Prevention (CDC), the Food and Drug Administration (FDA), and the US Department of Agriculture (USDA). The report provides a snapshot of resistance patterns found in bacteria isolated from humans, animals, raw meats from retail outlets (chicken, ground turkey, ground beef, and pork chops), and meat and poultry product samples collected at slaughtering facilities.

In addition to Salmonella, which causes an estimated 1.35 million illnesses and 26,500 hospitalizations each year, the NARMS report also includes resistance data on Campylobacter (1.5 million illnesses and 19,500 hospitalizations), Escherichia coli, and Enterococcus. NARMS monitors these bacteria to detect emerging resistance patterns to the antibiotics that are most important to human medicine, multidrug resistance, and specific resistance genes.