Identification and characterization of quaternary ammonium compound resistant staphylococci from the food industry

Qac efflux pumps from proteobacterial multidrug-resistant plasmids are integron-encoded and confer resistance to quaternary ammonium compound (QAC) antiseptics, however, many are uncharacterized and misannotated. A survey of >2000 plasmid-encoded qac identified 37 unique qac sequences that correspond to one of five representative motifs: QacE, QacEΔ1, QacF/L, QacH/I, and QacG. Antimicrobial susceptibility testing of each cloned qac member in Escherichia coli , highlighted distinctive antiseptic susceptibility patterns that were most prominent when cells grew as biofilms.

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Genetic Subtyping, Biofilm-Forming Ability and Biocide Susceptibility of Listeria monocytogenes Strains Isolated from a Ready-to-Eat Food Industry

Antibiotics ◽

10.3390/antibiotics9070416 ◽

2020 ◽

Vol 9 (7) ◽

pp. 416

Author(s):

Joana Catarina Andrade ◽

António Lopes João ◽

Carlos de Sousa Alonso ◽

António Salvador Barreto ◽

Ana Rita Henriques

Keyword(s):

Listeria Monocytogenes ◽

Quaternary Ammonium ◽

Benzalkonium Chloride ◽

Food Industry ◽

Raw Materials ◽

Foodborne Pathogen ◽

Positive Association ◽

Quaternary Ammonium Compound ◽

Ammonium Compound ◽

Food Grade

Listeria monocytogenes is a foodborne pathogen of special concern for ready-to-eat food producers. The control of its presence is a critical step in which food-grade sanitizers play an essential role. L. monocytogenes is believed to persist in food processing environments in biofilms, exhibiting less susceptibility to sanitizers than planktonic cells. This study aimed to test the susceptibility of L. monocytogenes in planktonic culture and biofilm to three commercial food-grade sanitizers and to benzalkonium chloride; together with the genetic subtyping of the isolates. L. monocytogenes isolates were collected from raw materials, final products and food-contact surfaces during a 6-year period from a ready-to-eat meat-producing food industry and genetically characterized. Serogrouping and pulsed-field gel electrophoresis (PFGE) revealed genetic variability and differentiated L. monocytogenes isolates in three clusters. The biofilm-forming ability assay revealed that the isolates were weak biofilm producers. L. monocytogenes strains were susceptible both in the planktonic and biofilm form to oxidizing and ethanol-based compounds and to benzalkonium chloride, but not to quaternary ammonium compound. A positive association of biofilm-forming ability and LD90 values for quaternary ammonium compound and benzalkonium chloride was found. This study highlights the need for preventive measures improvement and for a conscious selection and use of sanitizers in food-related environments to control Listeria monocytogenes.

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Tolerance to quaternary ammonium compound disinfectants may enhance growth of Listeria monocytogenes in the food industry

International Journal of Food Microbiology ◽

10.1016/j.ijfoodmicro.2016.10.025 ◽

2017 ◽

Vol 241 ◽

pp. 215-224 ◽

Cited By ~ 66

Author(s):

Trond Møretrø ◽

Bjørn C.T. Schirmer ◽

Even Heir ◽

Annette Fagerlund ◽

Pernille Hjemli ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Quaternary Ammonium ◽

Food Industry ◽

Quaternary Ammonium Compound ◽

Ammonium Compound

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Prevalence and Detection of qac Genes from Disinfectant-Resistant Staphylococcus aureus Isolated from Salon Tools in Ishaka Town, Bushenyi District of Uganda

Canadian Journal of Infectious Diseases and Medical Microbiology ◽

10.1155/2020/1470915 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Solange Gahongayire ◽

Adamu Almustapha Aliero ◽

Charles Drago Kato ◽

Alice Namatovu

Keyword(s):

Sodium Hypochlorite ◽

Quaternary Ammonium ◽

Bacterial Infections ◽

Healthcare Providers ◽

Quaternary Ammonium Compound ◽

Diffusion Method ◽

Ammonium Compound ◽

Bacterial Strains ◽

Microbiological Methods ◽

Phenotypic Methods

Bacterial infections are on a rise with causal-resistant strains increasing the economic burden to both patients and healthcare providers. Salons are recently reported as one of the sources for transmission of such resistant bacterial strains. The current study aimed at the identification of the prevalent bacteria and characterization of quaternary ammonium compound (qac) genes from disinfectant-resistant S. aureus isolated from salon tools in Ishaka town, Bushenyi District of Uganda. A total of 125 swabs were collected from different salon tools (combs, brushes, scissors, clippers, and shaving machines), and prevalent bacteria were isolated using standard microbiological methods. Identification of isolated bacteria was done using standard phenotypic methods including analytical profile index (API). Susceptibility patterns of the isolated bacteria to disinfectant were determined using the agar well diffusion method. Quaternary ammonium compound (qac) genes (qacA/B and qacC) associated with disinfectant resistances were detected from disinfectant-resistant S. aureus using multiplex polymerase chain reaction (PCR) and Sanger sequencing methods. Of the 125 swab samples collected from salons, 78 (62.4%) were contaminated with different bacteria species. Among the salon tools, clippers had the highest contamination of 20 (80.0%), while shaving machines had the lowest contamination of 11 (44.0%). The most prevalent bacteria identified were Staphylococcus epidermidis (28.1%) followed by S. aureus (26.5%). Of all the disinfectants tested, the highest resistance was shown with sodium hypochlorite 1%. Out of the eight (8) disinfectant-resistant S. aureus analysed for qac genes, 2 (25%) isolates (STP6 and STP9) were found to be qacA/B positive, while 2 (25%) isolates (STP8 and STP9) were found to be qacC gene positive. This study has shown that bacterial contamination of salon tools is common, coupled with resistance to disinfectants with sodium hypochlorite resistance being more common. Furthermore, observed resistance was attributed to the presence of qac genes among S. aureus isolates. A search for qac genes for disinfectant resistance from other bacteria species is recommended.

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