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Garcez DCP, Ribeiro G, Kominkiewicz M, da Costa MM, Chideroli RT, Rosa DS, Dos Santos IEP, Morante VHP, Silveira S, Girardini LK. Synergy between polypyrrol and benzoic acid against antibiotic-resistant Salmonella spp. J Appl Microbiol 2023; 134:lxad186. [PMID: 37656886 DOI: 10.1093/jambio/lxad186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 06/30/2023] [Accepted: 08/25/2023] [Indexed: 09/03/2023]
Abstract
AIMS The purpose was to characterize Salmonella Heidelberg (SH) and Minnesota (SM) isolates in terms of their resistance and persistence profile and to assess the antimicrobial effect of benzoic acid (BA) and polypyrrole (PPy). METHODS AND RESULTS The 20 isolates from broiler litter drag swabs were submitted to antibiogram and efflux pump expression. The minimum inhibitory/bactericidal concentration (MIC/MBC) of the compounds, synergistic activity, time kill, biofilm production, presence of related genes, and molecular docking between compounds and bacterial target sites were evaluated. All isolates showed multidrug resistance (MDR) and BA and PPy showed mean MIC (1750 and 342 µg ml-1) and MBC (3167 and 1000 µg ml-1), respectively. None of the isolates expressed an efflux pump. The compounds showed synergism against an SH isolate and reduced the count by 3 logs in the presence of the compounds after 4 h. Most isolates (16/20) produced weak to moderate biofilm and 17 showed genes related to biofilm. The compounds interacted with two essential proteins, 3,4-dihydroxy-2-butanone 4-phosphate synthase proteins and ferritin-like domain-containing protein, in bacterial metabolism at different target sites. CONCLUSIONS It can be concluded that BA and PPy showed activity on SH and SM, MDR, and biofilm producers, with a potential synergistic effect.
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Affiliation(s)
| | - Gabrielle Ribeiro
- University of West Santa Catarina (UNOESC), Xanxerê, State of Santa Catarina, 89600-000, Brazil
| | - Marcelo Kominkiewicz
- University of West Santa Catarina (UNOESC), Xanxerê, State of Santa Catarina, 89600-000, Brazil
| | - Mateus Matiuzzi da Costa
- Federal University of the São Francisco Valley (UNIVASF), Petrolina, State of Pernambuco, 56304-205, Brazil
| | - Roberta Torres Chideroli
- Federal University of the São Francisco Valley (UNIVASF), Petrolina, State of Pernambuco, 56304-205, Brazil
| | - Danillo Sales Rosa
- Federal Rural University of Pernambuco (UFRPE), Recife, State of Pernambuco, 52171-030, Brazil
| | | | | | - Simone Silveira
- University of West Santa Catarina (UNOESC), Xanxerê, State of Santa Catarina, 89600-000, Brazil
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Haddaji N, Bahloul B, Bahia W, Bechambi O, Mahdhi A. Development of Nanotechnology-Based Drug Delivery Systems for Controlling Clinical Multidrug-Resistant Staphylococcus aureus and Escherichia coli Associated with Aerobic Vaginitis. Pharmaceutics 2023; 15:2133. [PMID: 37631347 PMCID: PMC10460017 DOI: 10.3390/pharmaceutics15082133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/28/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
The growing prevalence of resistance to antibiotics potentially makes Escherichia coli and Staphylococcus aureus serious pathogens, necessitating the development of new antimicrobial agents. We extracted crude biosurfactants from a potential probiotic Bacillus spp. to control pathogenic bacteria associated with aerobic vaginal infection. Using nanotechnology formulations, we developed nanoemulsions based on biosurfactants at different concentrations (1% and 3.33%). The results showed that these nanoemulsions were stable, with a weighted index of 0.3, and demonstrated broad-spectrum antibacterial activity against Escherichia coli and Staphylococcus aureus, with MICs ranging between 1.25 and 4 mg/mL. Additionally, the nanoemulsions exhibited interesting antibiofilm effects. All strains became more sensitive to the antibiotics to which they were resistant because of various biosurfactant formulations combined with antibiotics. Lower concentrations of BNE1% and 3.33% were still more efficient than the crude biosurfactants. Our findings demonstrated that the biosurfactant had a strong antibiofilm effect against all tested pathogens. This antibacterial effect can be explained by their ability to alter cell physiology such as cell hydrophobicity and membrane disintegration. Thus, we can conclude that the use of nanotechnology formulations has improved this effect, and the nanoemulsions developed in this study can be used as a potential anti-infectious therapy against multidrug-resistant bacterial strains of clinical origin.
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Affiliation(s)
- Najla Haddaji
- Department of Biology, Faculty of Sciences, University of Ha’il, Ha’il 55436, Saudi Arabia;
- Laboratory of Analysis, Treatment and Valorization of the Pollutants of the Environment and the Products, Faculty of Pharmacy of Monastir, Monastir 5000, Tunisia;
| | - Badr Bahloul
- Pharmaceutical, Pharmacological & Chemical Drug Development Laboratory, Faculty of Pharmacy, University of Monastir, Monastir 5000, Tunisia;
| | - Wael Bahia
- Research Unit of Clinical and Molecular Biology (UR17ES29), Department of Biochemistry, Faculty of Pharmacy, University of Monastir, Monastir 5000, Tunisia;
| | - Olfa Bechambi
- Department of Biology, Faculty of Sciences, University of Ha’il, Ha’il 55436, Saudi Arabia;
| | - Abdelkarim Mahdhi
- Laboratory of Analysis, Treatment and Valorization of the Pollutants of the Environment and the Products, Faculty of Pharmacy of Monastir, Monastir 5000, Tunisia;
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3
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Adaptive microbial response to low-level benzalkonium chloride exposure. J Hosp Infect 2018; 100:e1-e22. [DOI: 10.1016/j.jhin.2018.05.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 05/24/2018] [Indexed: 12/12/2022]
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Shazer A, Stewart D, Deng K, Tortorello M. Approaches toward Identification of Surrogates To Validate Antimicrobial Washes as Preventive Controls for Fresh-Cut Leafy Greens. J Food Prot 2017; 80:1600-1604. [PMID: 28853631 DOI: 10.4315/0362-028x.jfp-17-069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In fresh-cut produce production, antimicrobials may be used during washing to control the risk of cross-contamination by microbial hazards. Surrogate microorganisms have long been used to validate processes, but none have been identified for validating the efficacy of antimicrobial washing of fresh-cut produce. The objective of this study was to develop procedures by which surrogates may be identified for use in validating the control of cross-contamination for fresh-cut lettuce operations. Four microbial characteristics, which may be important factors in cross-contamination events, were quantitatively evaluated in potential surrogate microorganisms for comparison to a reasonably foreseeable hazard, Escherichia coli O157:H7: sensitivity to chlorine in solution, sensitivity to chlorine on lettuce leaf surfaces, shedding from contaminated lettuce leaves into the water during washing, and cross-contamination from inoculated to uninoculated lettuce leaves during chorine washing. A procedure of practical quantitative experiments for comparing the characteristics reduced the original pool of 80 potential strains, which consisted of lactic acid bacteria, probiotics, and isolates obtained from lettuce enrichment cultures, to five strains: Lactobacillus plantarum, Pediococcus pentosaceus, probiotic 22C, and two lettuce enrichment isolates. These strains may be evaluated in additional studies involving comparisons to other reasonably foreseeable hazards and including other potential process variables that should be understood and controlled to prevent cross-contamination in fresh-cut lettuce operations.
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Affiliation(s)
- A Shazer
- 1 U.S. Food and Drug Administration, Division of Food Processing Science and Technology, Illinois Institute of Technology, 6502 South Archer Road, Bedford Park, Illinois 60501, USA
| | - D Stewart
- 1 U.S. Food and Drug Administration, Division of Food Processing Science and Technology, Illinois Institute of Technology, 6502 South Archer Road, Bedford Park, Illinois 60501, USA
| | - K Deng
- 2 Institute for Food Safety and Health, Illinois Institute of Technology, 6502 South Archer Road, Bedford Park, Illinois 60501, USA
| | - M Tortorello
- 1 U.S. Food and Drug Administration, Division of Food Processing Science and Technology, Illinois Institute of Technology, 6502 South Archer Road, Bedford Park, Illinois 60501, USA
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Møretrø T, Langsrud S. Residential Bacteria on Surfaces in the Food Industry and Their Implications for Food Safety and Quality. Compr Rev Food Sci Food Saf 2017; 16:1022-1041. [DOI: 10.1111/1541-4337.12283] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 06/03/2017] [Accepted: 06/06/2017] [Indexed: 12/15/2022]
Affiliation(s)
- Trond Møretrø
- Nofima, The Norwegian Inst. of Food; Fishery and Aquaculture Research; N-1430 Ås Norway
| | - Solveig Langsrud
- Nofima, The Norwegian Inst. of Food; Fishery and Aquaculture Research; N-1430 Ås Norway
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Fagerlund A, Langsrud S, Heir E, Mikkelsen MI, Møretrø T. Biofilm Matrix Composition Affects the Susceptibility of Food Associated Staphylococci to Cleaning and Disinfection Agents. Front Microbiol 2016; 7:856. [PMID: 27375578 PMCID: PMC4893552 DOI: 10.3389/fmicb.2016.00856] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 05/23/2016] [Indexed: 01/08/2023] Open
Abstract
Staphylococci are frequently isolated from food processing environments, and it has been speculated whether survival after cleaning and disinfection with benzalkonium chloride (BC)-containing disinfectants is due to biofilm formation, matrix composition, or BC efflux mechanisms. Out of 35 food associated staphylococci, eight produced biofilm in a microtiter plate assay and were identified as Staphylococcus capitis (2), S. cohnii, S. epidermidis, S. lentus (2), and S. saprophyticus (2). The eight biofilm producing strains were characterized using whole genome sequencing. Three of these strains contained the ica operon responsible for production of a polysaccharide matrix, and formed a biofilm which was detached upon exposure to the polysaccharide degrading enzyme Dispersin B, but not Proteinase K or trypsin. These strains were more tolerant to the lethal effect of BC both in suspension and biofilm than the remaining five biofilm producing strains. The five BC susceptible strains were characterized by lack of the ica operon, and their biofilms were detached by Proteinase K or trypsin, but not Dispersin B, indicating that proteins were major structural components of their biofilm matrix. Several novel cell wall anchored repeat domain proteins with domain structures similar to that of MSCRAMM adhesins were identified in the genomes of these strains, potentially representing novel mechanisms of ica-independent biofilm accumulation. Biofilms from all strains showed similar levels of detachment after exposure to alkaline chlorine, which is used for cleaning in the food industry. Strains with qac genes encoding BC efflux pumps could grow at higher concentrations of BC than strains without these genes, but no differences were observed at biocidal concentrations. In conclusion, the biofilm matrix of food associated staphylococci varies with respect to protein or polysaccharide nature, and this may affect the sensitivity toward a commonly used disinfectant.
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Affiliation(s)
- Annette Fagerlund
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research Ås, Norway
| | - Solveig Langsrud
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research Ås, Norway
| | - Even Heir
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research Ås, Norway
| | - Maria I Mikkelsen
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture ResearchÅs, Norway; Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life SciencesÅs, Norway
| | - Trond Møretrø
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research Ås, Norway
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Seier-Petersen MA, Nielsen LN, Ingmer H, Aarestrup FM, Agersø Y. Biocide Susceptibility of Staphylococcus aureus CC398 and CC30 Isolates from Pigs and Identification of the Biocide Resistance Genes, qacG and qacC. Microb Drug Resist 2015; 21:527-36. [PMID: 26430941 DOI: 10.1089/mdr.2014.0215] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Methicillin-resistant Staphylococcus aureus (MRSA), in particular clonal complex (CC) 398, is increasingly found in livestock. Recently, MRSA CC30 was identified in Danish pigs. We determined the susceptibility of porcine S. aureus isolates of CC398 and CC30 to disinfectants used in pig farming (benzalkonium chloride, hydrogen peroxide, formaldehyde, sodium hypochlorite, and caustic soda). Furthermore, efflux pump activity, antimicrobial resistance profiles, hemolysis properties, and the presence of toxic shock syndrome toxin-1 (TSST-1) and Panton-Valentine Leukocidin (PVL)-encoding virulence factors were investigated. METHODS Susceptibilities to biocides and antimicrobial agents of 79 porcine S. aureus isolates were determined by the microdilution method. Isolates comprised 21 methicillin-sensitive S. aureus (MSSA) and 40 MRSA isolates belonging to CC398 and 13 MSSA and 5 MRSA isolates belonging to CC30. The presence of quaternary ammonium compound (QAC) resistance efflux pumps was analyzed using an ethidium bromide accumulation assay. The presence of qac resistance genes in active efflux pump positive isolates was determined by whole-genome sequencing data. All isolates were screened for lukPV and tst genes with PCR, and hemolytic activities were determined using an agar plate assay. RESULTS S. aureus isolates did not show reduced susceptibility to the biocides tested. However, the QAC resistance gene, qacG, was detected in three MRSA CC30 isolates and the qacC in one MRSA CC30 isolate. CC30 isolates were generally more susceptible to non-beta-lactam antibiotics than CC398. Isolates generally had low hemolytic activity and none encoded PVL or TSST-1. CONCLUSION The presence of qac genes in European porcine S. aureus isolates and in livestock-associated MRSA CC30 is for the first time described in this study. This finding is concerning as it ultimately may compromise disinfection with QACs and thereby contribute to the selection and spread of MRSA CC30.
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Affiliation(s)
- Maria Amalie Seier-Petersen
- 1 Division for Epidemiology and Microbial Genomics, National Food Institute, Technical University of Denmark , Lyngby, Denmark
| | - Lene Nørby Nielsen
- 2 Department of Veterinary Disease Biology, Faculty of Health, University of Copenhagen , Copenhagen, Denmark
| | - Hanne Ingmer
- 2 Department of Veterinary Disease Biology, Faculty of Health, University of Copenhagen , Copenhagen, Denmark
| | - Frank Møller Aarestrup
- 1 Division for Epidemiology and Microbial Genomics, National Food Institute, Technical University of Denmark , Lyngby, Denmark
| | - Yvonne Agersø
- 1 Division for Epidemiology and Microbial Genomics, National Food Institute, Technical University of Denmark , Lyngby, Denmark
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Methicillin-resistant Staphylococcus aureus in commercial swine herds is associated with disinfectant and zinc usage. Appl Environ Microbiol 2015; 81:2690-5. [PMID: 25662976 DOI: 10.1128/aem.00036-15] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) originating from swine is concerning for public health, but an understanding of the emergence and persistence of MRSA in nursery herds is lacking. The aim of this study was to determine whether MRSA in nursery pigs is associated with particular herd-level parameters, including the use of antimicrobials, disinfectants, and heavy metals, which may be driving the selection and persistence of antimicrobial resistance. Nasal cultures for MRSA were completed for 390 pigs from 26 farms at the end of the suckling phase and again at 3 weeks postweaning. Herd-level information was collected, and a random subset of MRSA isolates was screened for resistance to zinc and quaternary ammonium compounds (QACs). Multivariate analysis revealed that in-feed concentrations of zinc (P < 0.001) and frequent disinfection of nursery pens (P < 0.001) are associated with MRSA shedding in nursery pigs. Furthermore, 62.5% (25/40) of MRSA isolates carried the zinc resistance gene czrC and demonstrated decreased susceptibility to zinc. All MRSA isolates carried at least 1 QAC resistance gene. The most common genotype was qacG qacH smr, which occurred in 32.5% (13/40) of isolates. Seven isolates (17.5%) demonstrated a significant tolerance to benzalkonium chloride, indicating a potential to survive commercial QAC exposure in the presence of organic matter. Overall, these findings indicate that high levels of in-feed zinc and QAC-based disinfectants are important drivers in the selection and persistence of MRSA in commercial swine herds, and these agents may be coselecting for other antimicrobial resistance genes.
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9
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Biofilm formation, attachment, and cell hydrophobicity of foodborne pathogens under varied environmental conditions. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/s13765-012-3253-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Caballero Gómez N, Abriouel H, Grande MJ, Pérez Pulido R, Gálvez A. Combined treatments of enterocin AS-48 with biocides to improve the inactivation of methicillin-sensitive and methicillin-resistant Staphylococcus aureus planktonic and sessile cells. Int J Food Microbiol 2013; 163:96-100. [PMID: 23558192 DOI: 10.1016/j.ijfoodmicro.2013.02.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2012] [Revised: 02/17/2013] [Accepted: 02/18/2013] [Indexed: 01/01/2023]
Abstract
Control of staphylococci during cleaning and disinfection is important to the food industry. Broad-spectrum bacteriocins with proved anti-staphylococcal activity, such as enterocin AS-48, could open new possibilities for disinfection in combination with biocides. In the present study, enterocin AS-48 was tested singly or in combination with biocides against a cocktail of six Staphylococcus aureus strains (including three methicillin-resistant strains) in planktonic state as well as in biofilms formed on polystyrene microtiter plates. Cells were challenged with enterocin, biocides or enterocin/biocide combinations. Inactivation of planktonic cells increased significantly (p<0.05) when enterocin AS-48 (25mg/l) was tested in combination with benzalkonium chloride (BC), cetrimide (CT) and hexadecylpyridinium chloride (HDP), and non-significantly in combination with didecyldimethylammonium bromide (AB), triclosan (TC), hexachlorophene (CF), polyhexamethylen guanidinium chloride (PHMG), chlorhexidine (CH) or P3-oxonia (OX). In the sessile state (24h biofilms), staphylococci required higher biocide concentrations in most cases, except for OX. Inactivation of sessile staphylococci increased remarkably when biocides were applied in combination with enterocin AS-48, especially when the bacteriocin was added at 50mg/l. During storage, the concentrations of sessile as well as planktonic cells in the treated samples decreased remarkably for BC, TC and PHMG, but OX failed to inhibit proliferation of the treated biofilms as well as growth of planktonic cells. The observed inhibitory effects during storage were potentiated when the biocides were combined with 50 mg/l enterocin AS-48. Results from this study suggest that selected combinations of enterocin AS-48 and biocides offer potential use against planktonic and sessile, methicillin-sensitive and methicillin-resistant S. aureus.
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Affiliation(s)
- Natacha Caballero Gómez
- Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071 Jaén, Spain
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11
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Biocide tolerance in bacteria. Int J Food Microbiol 2013; 162:13-25. [PMID: 23340387 DOI: 10.1016/j.ijfoodmicro.2012.12.028] [Citation(s) in RCA: 150] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 10/24/2012] [Accepted: 12/15/2012] [Indexed: 02/07/2023]
Abstract
Biocides have been employed for centuries, so today a wide range of compounds showing different levels of antimicrobial activity have become available. At the present time, understanding the mechanisms of action of biocides has also become an important issue with the emergence of bacterial tolerance to biocides and the suggestion that biocide and antibiotic resistance in bacteria might be linked. While most of the mechanisms providing antibiotic resistance are agent specific, providing resistance to a single antimicrobial or class of antimicrobial, there are currently numerous examples of efflux systems that accommodate and, thus, provide tolerance to a broad range of structurally unrelated antimicrobials, both antibiotics and biocides. If biocide tolerance becomes increasingly common and it is linked to antibiotic resistance, not only resistant (even multi-resistant) bacteria could be passed along the food chain, but also there are resistance determinants that can spread and lead to the emergence of new resistant microorganisms, which can only be detected and monitored when the building blocks of resistance traits are understood on the molecular level. This review summarizes the main advances reached in understanding the mechanism of action of biocides, the mechanisms of bacterial resistance to both biocides and antibiotics, and the incidence of biocide tolerance in bacteria of concern to human health and the food industry.
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Lavilla Lerma L, Benomar N, Gálvez A, Abriouel H. Prevalence of bacteria resistant to antibiotics and/or biocides on meat processing plant surfaces throughout meat chain production. Int J Food Microbiol 2012; 161:97-106. [PMID: 23279818 DOI: 10.1016/j.ijfoodmicro.2012.11.028] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 10/24/2012] [Accepted: 11/21/2012] [Indexed: 12/18/2022]
Abstract
In order to investigate the prevalence of resistant bacteria to biocides and/or antibiotics throughout meat chain production from sacrifice till end of production line, samples from various surfaces of a goat and lamb slaughterhouse representative of the region were analyzed by the culture dependent approach. Resistant Psychrotrophs (n=255 strains), Pseudomonas sp. (n=166 strains), E. coli (n=23 strains), Staphylococcus sp. (n=17 strains) and LAB (n=82 represented mainly by Lactobacillus sp.) were isolated. Resistant psychrotrophs and pseudomonads (47 and 29%, respectively) to different antimicrobials were frequently detected in almost all areas of meat processing plant regardless the antimicrobial used, although there was a clear shift in the spectrum of other bacterial groups and for this aim such resistance was determined according to several parameters: antimicrobial tested, sampling zone and the bacterial group. Correlation of different parameters was done using a statistical tool "Principal component analysis" (PCA) which determined that quaternary ammonium compounds and hexadecylpyridinium were the most relevant biocides for resistance in Pseudomonas sp., while ciprofloxacin and hexachlorophene were more relevant for psychrotrophs, LAB, and in lesser extent Staphylococcus sp. and Escherichia coli. On the other hand, PCA of sampling zones determined that sacrifice room (SR) and cutting room (CR) considered as main source of antibiotic and/or biocide resistant bacteria showed an opposite behaviour concerning relevance of antimicrobials to determine resistance being hexadecylpyridinium, cetrimide and chlorhexidine the most relevant in CR, while hexachlorophene, oxonia 6P and PHMG the most relevant in SR. In conclusion, rotational use of the relevant biocides as disinfectants in CR and SR is recommended in an environment which is frequently disinfected.
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Affiliation(s)
- Leyre Lavilla Lerma
- Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071-Jaén, Spain
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Marchand S, De Block J, De Jonghe V, Coorevits A, Heyndrickx M, Herman L. Biofilm Formation in Milk Production and Processing Environments; Influence on Milk Quality and Safety. Compr Rev Food Sci Food Saf 2012. [DOI: 10.1111/j.1541-4337.2011.00183.x] [Citation(s) in RCA: 202] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Møretrø T, Heir E, Mo K, Habimana O, Abdelgani A, Langsrud S. Factors affecting survival of Shigatoxin-producing Escherichia coli on abiotic surfaces. Int J Food Microbiol 2010; 138:71-7. [DOI: 10.1016/j.ijfoodmicro.2010.01.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Revised: 01/01/2010] [Accepted: 01/04/2010] [Indexed: 10/20/2022]
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15
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Cabo M, Herrera J, Crespo M, Pastoriza L. Comparison among the effectiveness of ozone, nisin and benzalkonium chloride for the elimination of planktonic cells and biofilms of Staphylococcus aureus CECT4459 on polypropylene. Food Control 2009. [DOI: 10.1016/j.foodcont.2008.08.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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16
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Kastbjerg VG, Gram L. Model systems allowing quantification of sensitivity to disinfectants and comparison of disinfectant susceptibility of persistent and presumed nonpersistentListeria monocytogenes. J Appl Microbiol 2009; 106:1667-81. [PMID: 19226386 DOI: 10.1111/j.1365-2672.2008.04134.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- V G Kastbjerg
- National Institute of Aquatic Resources, Technical University of Denmark, Kgs. Lyngby, Denmark.
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Bjorland J, Bratlie MS, Steinum T. The smr gene resides on a novel plasmid pSP187 identified in a Staphylococcus pasteuri isolate recovered from unpasteurized milk. Plasmid 2007; 57:145-55. [PMID: 17074390 DOI: 10.1016/j.plasmid.2006.08.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2005] [Revised: 04/25/2006] [Accepted: 08/06/2006] [Indexed: 11/26/2022]
Abstract
UNLABELLED This work describes a novel plasmid pSP187 (5550 bp) carrying the small multidrug resistance determinant smr encoding resistance to quaternary ammonium compounds (QACs). pSP187 was identified in a Staphylococcus pasteuri isolate recovered from bulk milk in a dairy cattle herd in Norway. Sequence analysis revealed 6 putative ORFs in addition to the smr gene within a cassette with identical genetic organization to that found in the pSK41-like Staphylococcus aureus plasmid pTZ22. A protein homology search suggested the gene product of ORF7 to be a putative replication initiation protein, while ORF2 was predicted to encode a protein homologous to members of FtsK/SpoIIIE cell division-DNA segregation protein families. Sequence similarities to some initiator proteins of rolling circle replicons (RCR) indicated that pSP187 uses a RCR mode of replication, supported by the detection of intermediate ssDNA using S1 nuclease treatment and hybridization analysis. Interestingly, a 30-bp sequence found upstream from ORF7 showed high similarity to other dyad symmetry motifs proposed as putative double-strand origins of replication in the plasmids pGI3 (Bacillus thuringiensis), pSTK1 (Bacillus stearothermophilus), and pER1-2 (Streptococcus thermophilus). IN CONCLUSION The novel smr-containing plasmid pSP187 is the first member of RCR group VI to be identified in a Staphylococcus sp.
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Affiliation(s)
- Jostein Bjorland
- Department of Production Animal Clinical Sciences, Norwegian School of Veterinary Science, P.O. Box 8146 Dep, N-0033 Oslo, Norway.
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Takenaka S, Tonoki T, Taira K, Murakami S, Aoki K. Adaptation of Pseudomonas sp. strain 7-6 to quaternary ammonium compounds and their degradation via dual pathways. Appl Environ Microbiol 2007; 73:1797-802. [PMID: 17261523 PMCID: PMC1828831 DOI: 10.1128/aem.02426-06] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas sp. strain 7-6, isolated from active sludge obtained from a wastewater facility, utilized a quaternary ammonium surfactant, n-dodecyltrimethylammonium chloride (DTAC), as its sole carbon, nitrogen, and energy source. When initially grown in the presence of 10 mM DTAC medium, the isolate was unable to degrade DTAC. The strain was cultivated in gradually increasing concentrations of the surfactant until continuous exposure led to high tolerance and biodegradation of the compound. Based on the identification of five metabolites by gas chromatography-mass spectrometry analysis, two possible pathways for DTAC metabolism were proposed. In pathway 1, DTAC is converted to lauric acid via n-dodecanal with the release of trimethylamine; in pathway 2, DTAC is converted to lauric acid via n-dodecyldimethylamine and then n-dodecanal with the release of dimethylamine. Among the identified metabolites, the strain precultivated on DTAC medium could utilize n-dodecanal and lauric acid as sole carbon sources and trimethylamine and dimethylamine as sole nitrogen sources, but it could not efficiently utilize n-dodecyldimethylamine. These results indicated pathway 1 is the main pathway for the degradation of DTAC.
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Affiliation(s)
- Shinji Takenaka
- Department of Biofunctional Chemistry, Faculty of Agriculture, Kobe University, Rokko, Nada-ku, Kobe, Japan
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Romanova NA, Wolffs PFG, Brovko LY, Griffiths MW. Role of efflux pumps in adaptation and resistance of Listeria monocytogenes to benzalkonium chloride. Appl Environ Microbiol 2006; 72:3498-503. [PMID: 16672496 PMCID: PMC1472371 DOI: 10.1128/aem.72.5.3498-3503.2006] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, potential mechanisms underlying resistance and adaptation to benzalkonium chloride (BC) in Listeria monocytogenes were investigated. Two groups of strains were studied. The first group consisted of strains naturally sensitive to BC which could be adapted to BC. The second group consisted of naturally resistant strains. For all adapted isolates, there was a correlation between the resistance to BC and ethidium bromide, but this was not the case for the naturally resistant isolates. To investigate the role of efflux pumps in adaptation or resistance, reserpine, an efflux pump inhibitor, was added to the strains. Addition of reserpine to the sensitive and adapted strains resulted in a decrease in the MIC for BC, whereas no such decrease was observed for the resistant strains, indicating that efflux pumps played no role in the innate resistance of certain strains of L. monocytogenes to this compound. Two efflux pumps (MdrL and Lde) have been described in L. monocytogenes. Studies showed low and intermediate levels of expression of the genes encoding the efflux pumps for two selected resistant strains, H7764 and H7962, respectively. Adaptation to BC of sensitive isolates of L. monocytogenes resulted in significant increases in expression of mdrl (P < 0.05), but no such increase was observed for lde for two adapted strains of L. monocytogenes, LJH 381 (P = 0.91) and C719 (P = 0.11). This indicates that the efflux pump Mdrl is at least partly responsible for the adaptation to BC.
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Affiliation(s)
- N A Romanova
- Canadian Research Institute for Food Safety, University of Guelph, 43 McGilvray Street, Guelph, Ontario, Canada N1G 2W1
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21
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Møretrø T, Sonerud T, Mangelrød E, Langsrud S. Evaluation of the antibacterial effect of a triclosan-containing floor used in the food industry. J Food Prot 2006; 69:627-33. [PMID: 16541695 DOI: 10.4315/0362-028x-69.3.627] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Antibacterial surfaces are increasingly used in the food industry. In the present study, the antibacterial effect of a triclosan-containing industrial floor was assessed. A poultry processing plant, which had a floor that contained triclosan, was visited, and the floor was sampled for bacteria. A high bacterial diversity was found on the floor. Testing showed that bacteria isolated from the floor showed a sensitivity to triclosan that covered a range of MICs from 0.07 to >40 ppm. Staphylococci were the most sensitive, and Pseudomonas fluorescens and Serratia marcescens were the most tolerant. The MICs of triclosan for the strains isolated from the floor were similar to the control strains from the corresponding genera or species of other origin. Thus, the floor seemed not to select for strains that were tolerant to triclosan or that led to the development of resistance to triclosan. Laboratory studies showed that the ability of bacteria to survive under dry conditions on coupons of the floor was similar to that for stainless steel and that the survival of the bacteria on the floor was not linked to their tolerance of triclosan, as determined by the MICs of triclosan. Adherence studies showed that bacteria were able to adhere to coupons of the floor; however, no thick biofilm developed after 3 days of incubation. In an agar plate assay, the floor produced inhibition zones against staphylococci, which are known to be very sensitive to triclosan, whereas no inhibition zones were observed for other bacteria tested. In conclusion, the antibacterial effect of the floor seemed to be very low. Because the concentration of triclosan in the floor was low compared to what has been reported for other triclosan-incorporated surfaces, sufficient amounts of triclosan may not have been available on the surface of the floor to kill the bacteria.
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Affiliation(s)
- Trond Møretrø
- Matforsk AS, Norwegian Food Research Institute, Osloveien 1, N-1430 Aas, Norway.
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22
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Bjorland J, Steinum T, Kvitle B, Waage S, Sunde M, Heir E. Widespread distribution of disinfectant resistance genes among staphylococci of bovine and caprine origin in Norway. J Clin Microbiol 2005; 43:4363-8. [PMID: 16145078 PMCID: PMC1234083 DOI: 10.1128/jcm.43.9.4363-4368.2005] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We demonstrate here a widespread distribution of genes mediating efflux-based resistance to quaternary ammonium compounds (QACs) in staphylococci from unpasteurized milk from 127 dairy cattle herds and 70 dairy goat herds. QAC resistance genes were identified in 21% of the cattle herds (qacA/B, smr, qacG, and qacJ) and in 10% of the goat herds (qacA/B and smr). Further examination of 42 QAC-resistant bovine and caprine isolates revealed the following genes: qacA/B (12 isolates) was present in four different species of coagulase-negative staphylococci (CoNS), smr (27 isolates) was detected in eight different CoNS species and in Staphylococcus aureus on a previously reported plasmid (pNVH99), qacG (two isolates) was detected on two plasmids (pST94-like) in Staphylococcus cohnii and Staphylococcus warneri, and qacJ (two isolates) was found in Staphylococcus hominis and Staphylococcus delphini on a plasmid (pNVH01) previously found in equine staphylococci. Isolation of indistinguishable pulsed-field gel electrophoresis (PFGE) CoNS types from tank milk and mammary quarter milk samples in a dairy cattle herd suggested that these QAC-resistant staphylococci were of intramammary origin. Indistinguishable or closely related PFGE types of bovine QAC-resistant CoNS were observed in different herds. One particular bovine S. warneri PFGE type was isolated repeatedly from samples collected during a 30-month period in a herd, showing long-term persistence. In conclusion, it seems that the widespread distribution of staphylococci carrying QAC resistance genes in Norwegian dairy cattle and goat herds is the result of both the intra- and interspecies spread of QAC resistance plasmids and the clonal spread of QAC-resistant strains.
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Affiliation(s)
- Jostein Bjorland
- Department of Production Animal Clinical Sciences, Norwegian School of Veterinary Science, Oslo.
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23
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Heir E, Lindstedt BA, Røtterud OJ, Vardund T, Kapperud G, Nesbakken T. Molecular epidemiology and disinfectant susceptibility of Listeria monocytogenes from meat processing plants and human infections. Int J Food Microbiol 2004; 96:85-96. [PMID: 15358509 DOI: 10.1016/j.ijfoodmicro.2004.03.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2003] [Revised: 02/13/2004] [Accepted: 03/11/2004] [Indexed: 10/26/2022]
Abstract
We have investigated the molecular epidemiology of Listeria monocytogenes from the meat processing industry producing cold cuts and from cases of human listeriosis by discriminative pulsed-field gel electrophoresis (PFGE). A subset of the isolates was also investigated for susceptibility to a disinfectant based on quaternary ammonium compounds (QAC) frequently used in the meat processing industry. The purpose of this investigation was to obtain knowledge of sources, routes of contamination and genetic types of L. monocytogenes present along the production line in the meat processing industry, and to compare meat industry isolates and human isolates. Of the 222 isolates from four meat-processing plants, 200 were from two plants responsible for nearly 50% of the production of cold cuts in the Norwegian market. The strain collection included historical routinely sampled isolates (1989-2002) and isolates systematically sampled through a one year period (November 2001 to November 2002) from fresh meat and production environments in three plants. No isolates were obtained in samples from employees (throat, faeces). Human strains included all available reported isolates from Norwegian patients in selected time periods. The L. monocytogenes PFGE data showed a large genetic heterogeneity, with isolates separated into two genetic lineages and further subdivided into 56 different PFGE profiles. Certain profiles were observed on both sides of production (before and after heat treatment) indicating contamination of end products by fresh meat or fresh meat environments. While fresh meat isolates almost exclusively grouped within lineage I, isolates from end products showed a more balanced distribution between lineages I and II. Ten profiles were common among isolates from human and meat industry. Typing of human isolates identified a previously unrecognised outbreak. Generally, a higher QAC resistance incidence was observed among isolates from the meat processing industry than among human isolates although large plant to plant differences were indicated. No correlation between resistance and PFGE profile or resistance and persistence was observed.
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Affiliation(s)
- Even Heir
- Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo, Norway.
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24
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Bjorland J, Steinum T, Sunde M, Waage S, Heir E. Novel plasmid-borne gene qacJ mediates resistance to quaternary ammonium compounds in equine Staphylococcus aureus, Staphylococcus simulans, and Staphylococcus intermedius. Antimicrob Agents Chemother 2004; 47:3046-52. [PMID: 14506007 PMCID: PMC201118 DOI: 10.1128/aac.47.10.3046-3052.2003] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We identified a novel plasmid-borne gene (designated qacJ) encoding resistance to quaternary ammonium compounds (QACs) in three staphylococcal species associated with chronic infections in four horses. qacJ was located on a 2,650-bp plasmid (designated pNVH01), a new member of the pC194 family of rolling-circle replication plasmids. The 107-amino-acid protein, QacJ, showed similarities to known proteins of the small multidrug resistance family: Smr/QacC (72.5%), QacG (82.6%), and QacH (73.4%). The benzalkonium chloride MIC for a qacJ-containing recombinant was higher than those for otherwise isogenic recombinants expressing Smr, QacG, or QacH. Molecular epidemiological analyses by pulsed-field gel electrophoresis suggested both the clonal spread of a qacJ-harboring Staphylococcus aureus strain and the horizontal transfer of pNVH01 within and between different equine staphylococcal species. The presence of pNVH01 of identical nucleotide sequence in different staphylococcal species suggests that recent transfer has occurred. In three of the horses, a skin preparation containing cetyltrimethylammonium bromide had been used extensively for several years; this might explain the selection of staphylococci harboring the novel QAC resistance gene.
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Affiliation(s)
- Jostein Bjorland
- Department of Reproduction and Forensic Medicine, The Norwegian School of Veterinary Science, Oslo, Norway.
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Langsrud S, Møretrø T, Sundheim G. Characterization of Serratia marcescens surviving in disinfecting footbaths. J Appl Microbiol 2003; 95:186-95. [PMID: 12807470 DOI: 10.1046/j.1365-2672.2003.01968.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIM To determine if disinfecting footbaths in the food industry were contaminated with bacteria and to characterize some of the bacteria present. METHODS AND RESULTS Bacterial strains were isolated from disinfecting footbaths containing TEGO 103G (amphoteric disinfectant) or TP-99 (alkyl amino acetate-based disinfectant) in five of six dairy factories. Fourteen strains identified as Cedecea spp. by their fatty acid composition were further characterized. Results from Rapid ID 32 E API analysis and 16S-rDNA-sequencing showed that all strains were Serratia marcescens. Unlike S. marcescens ATCC 13880, the isolates from disinfecting footbaths were not killed (<5 log10 reduction) by the recommended in-use concentration of TEGO 103G, TEGO 51 or benzalkonium chloride. Survival and multiplication in tap water with an in-use concentration of TEGO 103G was demonstrated for one of the strains. All strains were killed by the in-use concentrations of commercial disinfectants based on peracetic acid, hypochlorite, quaternary ammonium compounds and alkyl amino acetate (TP-99). There were no indications of cross-resistance between disinfectants and antibiotics. CONCLUSION Serratia marcescens may survive and multiply in disinfecting footbaths containing TEGO 103G or alkyl amino acetate because of disinfectant resistance. SIGNIFICANCE AND IMPACT OF THE STUDY Disinfecting footbaths may act as contamination sources in food factories and should not be used without regular hygienic monitoring.
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Affiliation(s)
- S Langsrud
- MATFORSK, Norwegian Food Research Institute, As, Norway.
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26
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Møretrø T, Hermansen L, Holck AL, Sidhu MS, Rudi K, Langsrud S. Biofilm formation and the presence of the intercellular adhesion locus ica among staphylococci from food and food processing environments. Appl Environ Microbiol 2003; 69:5648-55. [PMID: 12957956 PMCID: PMC194930 DOI: 10.1128/aem.69.9.5648-5655.2003] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In clinical staphylococci, the presence of the ica genes and biofilm formation are considered important for virulence. Biofilm formation may also be of importance for survival and virulence in food-related staphylococci. In the present work, staphylococci from the food industry were found to differ greatly in their abilities to form biofilms on polystyrene. A total of 7 and 21 of 144 food-related strains were found to be strong and weak biofilm formers, respectively. Glucose and sodium chloride stimulated biofilm formation. The biofilm-forming strains belonged to nine different coagulase-negative species of Staphylococcus. The icaA gene of the intercellular adhesion locus was detected by Southern blotting and hybridization in 38 of 67 food-related strains tested. The presence of icaA was positively correlated with strong biofilm formation. The icaA gene was partly sequenced for 22 food-related strains from nine different species of Staphylococcus, and their icaA genes were found to have DNA similarities to previously sequenced icaA genes of 69 to 100%. Northern blot analysis indicated that the expression of the ica genes was higher in strong biofilm formers than that seen with strains not forming biofilms. Biofilm formation on polystyrene was positively correlated with biofilm formation on stainless steel and with resistance to quaternary ammonium compounds, a group of disinfectants.
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Affiliation(s)
- Trond Møretrø
- MATFORSK, Norwegian Food Research Institute, N-1430 As, Norway.
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27
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Romanova N, Favrin S, Griffiths MW. Sensitivity of Listeria monocytogenes to sanitizers used in the meat processing industry. Appl Environ Microbiol 2002; 68:6405-9. [PMID: 12450868 PMCID: PMC134375 DOI: 10.1128/aem.68.12.6405-6409.2002] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Nineteen Listeria monocytogenes strains were characterized by automated ribotyping, pulsed-field gel electrophoresis, and plasmid profiling to determine the relationship between genotype and sanitizer resistance. Isolates within a ribogroup had a consistent sensitivity or resistance phenotype except for ribogroup C isolates. All isolates with resistance phenotypes harbored two plasmids. The sensitivity of L. monocytogenes strains to quaternary ammonium compounds (QACs) was correlated with sensitivity to sanitizers and antibiotics with other modes of action. All isolates tested contained the mdrL gene, which encodes an efflux pump that confers resistance to QACs and is both chromosome and plasmid borne.
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Affiliation(s)
- Nadya Romanova
- Canadian Research Institute for Food Safety, University of Guelph, Ontario, Canada N1G 2W1
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28
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To MS, Favrin S, Romanova N, Griffiths MW. Postadaptational resistance to benzalkonium chloride and subsequent physicochemical modifications of Listeria monocytogenes. Appl Environ Microbiol 2002; 68:5258-64. [PMID: 12406712 PMCID: PMC129876 DOI: 10.1128/aem.68.11.5258-5264.2002] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2002] [Accepted: 08/05/2002] [Indexed: 11/20/2022] Open
Abstract
Many studies have demonstrated that bacteria, including Listeria monocytogenes, are capable of adapting to disinfectants used in industrial settings after prolonged exposure to sublethal concentrations. However, the consequent alterations of the cell surface due to sanitizer adaptation of this pathogen are not fully understood. Two resistant and four sensitive L. monocytogenes strains from different sources were progressively subcultured with increasing sublethal concentrations of a surfactant, benzalkonium chloride (BC). To evaluate the effects of acquired tolerance to BC, parent and adapted strains were compared by using several morphological and physiological tests. Sensitive strains showed at least a fivefold increase in the MIC, while the MIC doubled for resistant strains after the adaptation period. The hydrophobicities of cells of parent and adapted strains were similar. Serological testing indicated that antigen types 1 and 4 were both present on the cell surface of adapted cells. The data suggest that efflux pumps are the major mechanism of adaptation in sensitive strains and are less important in originally resistant isolates. A different, unknown mechanism was responsible for the original tolerance of resistant isolates. In an originally resistant strain, there was a slight shift in the fatty acid profile after adaptation, whereas sensitive strains had similar profiles. Electron micrographs revealed morphological differences after adaptation. The changes in cell surface antigens, efflux pump utilization, and fatty acid profiles suggest that different mechanisms are used by resistant and sensitive strains for adaptation to BC.
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Affiliation(s)
- Monica S To
- Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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29
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Anthonisen IL, Sunde M, Steinum TM, Sidhu MS, Sørum H. Organization of the antiseptic resistance gene qacA and Tn552-related beta-lactamase genes in multidrug- resistant Staphylococcus haemolyticus strains of animal and human origins. Antimicrob Agents Chemother 2002; 46:3606-12. [PMID: 12384372 PMCID: PMC128698 DOI: 10.1128/aac.46.11.3606-3612.2002] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A part (12 kb) of a plasmid containing the beta-lactamase genes of Tn552, the disinfectant resistance gene qacA, and flanking DNA has been cloned from a Staphylococcus haemolyticus isolate and sequenced. This region was used to map the corresponding regions in six other multiresistant S. haemolyticus isolates of human and animal origin. The organizations of the genetic structures were almost identical in all isolates studied. The beta-lactamase and qacA genes from S. haemolyticus have >99.9% identities at the nucleotide level with the same genes from S. aureus, demonstrating that various staphylococcal species able to colonize animal and human hosts can exchange the genetic elements involved in resistance to antibiotics and disinfectants. The use of antibiotics and disinfectants in veterinary practice and animal husbandry may also contribute to the selection and maintenance of resistance factors among the staphylococcal species. Different parts of the 12-kb section analyzed had high degrees of nucleotide identity with regions from several other different Staphylococcus aureus plasmids. This suggests the contribution of interplasmid recombination in the evolutionary makeup of this 12-kb section involving plasmids that can intermingle between various staphylococcal species. The lateral spread of resistance genes between various staphylococcal species is probably facilitated by the generation of large multiresistance plasmids and the subsequent interspecies exchange of them.
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Affiliation(s)
- I-L Anthonisen
- Department of Pharmacology, Microbiology, and Food Hygiene, The Norwegian School of Veterinary Science, 0033 Oslo. MATFORSK, Norwegian Food Research Institute, N-1430 As, Norway
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Sidhu MS, Heir E, Sørum H, Holck A. Genetic linkage between resistance to quaternary ammonium compounds and beta-lactam antibiotics in food-related Staphylococcus spp. Microb Drug Resist 2002; 7:363-71. [PMID: 11822776 DOI: 10.1089/10766290152773374] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Little is known about the occurrence of antimicrobial resistance determinants in staphylococci isolated from food and food processing industries. Quaternary ammonium compound (QAC)-resistant coagulase-negative staphylococci (CNS) isolated from food and food-processing industries were investigated for the presence of genetic determinants (qacA/B and qacC/smr) encoding resistance to the QAC benzalkonium chloride (BC), several antibiotic resistance genes, and staphylococcal insertion sequences IS257 and IS256. Six qacA/B-harboring strains were resistant to penicillin and hybridized to a blaZ probe. The qacA/B and blaZ probes hybridized to plasmids of similar size in three isolates. Molecular and genetic characterization of the 23-kb plasmid (pST6) of Staphylococcus epidermidis St.6 revealed the presence of qacB adjacent to an incomplete beta-lactamase transposon Tn552 encoding the gene cluster blaZ, blaR, and blaI. Sequence analysis of flanking regions and the intergenic region between blaZ and qacB revealed the presence of IS257 downstream of blaZ as well as sin and binR between blaZ and qacB. In the three other BC and penicillin-resistant strains, the qacA/B and blaZ genes were located on separate plasmids. A qacC harboring S. epidermidis strain (St.17) also hybridized to tetK (tetracycline resistance) and ermB (erythromycin resistance) genes. The individual genes were located on separate plasmids, suggesting no linkage between QAC and antibiotic resistance determinants. Plasmid-free Staphylococcus aureus RN4220 allowed uptake of the pST6 plasmid DNA, indicating that the resistance genes could potentially be transferred to pathogens under selective stress. In conclusion, presence of both resistance determinants could lead to co-selection during antimicrobial therapy or disinfection in hospitals or in food industries.
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Affiliation(s)
- M S Sidhu
- MATFORSK, Norwegian Food Research Institute, As.
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31
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Bjorland J, Sunde M, Waage S. Plasmid-borne smr gene causes resistance to quaternary ammonium compounds in bovine Staphylococcus aureus. J Clin Microbiol 2001; 39:3999-4004. [PMID: 11682521 PMCID: PMC88478 DOI: 10.1128/jcm.39.11.3999-4004.2001] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Resistance to quaternary ammonium compounds (QAC) in staphylococci is common in hospital environments and has been described in the food industry. Little is known about staphylococcal QAC resistance associated with animal disease, although such disinfectants are widely used in veterinary medicine. In order to investigate the occurrence of QAC resistance in staphylococci isolated from QAC-exposed animals, 32 penicillin- and tetracycline-resistant and 23 penicillin- and tetracycline-susceptible Staphylococcus aureus isolates collected from milk from cows with mastitis during a 4-year period were selected for QAC susceptibility studies and genetic characterization. The isolates originated from four different herds that used a common pasture with a joint milking parlor in the summer. During the pasture season, a teat cream containing the QAC cetyltrimethylammonium bromide had been used daily for more than 10 years for mastitis control. Three of the penicillin- and tetracycline-resistant isolates, which were recovered from three different cows during a 20-month period, were resistant to QAC. Plasmid analysis, PCR, and DNA sequencing revealed a novel plasmid of 2,239 bp containing the smr gene. The plasmid, designated pNVH99, has similarities to small, smr-containing staphylococcal plasmids previously found in human and food isolates. pNVH99 is a new member of the pC194 family of rolling-circle replication plasmids. The three QAC-resistant isolates, as well as 28 of the 29 remaining penicillin- and tetracycline-resistant isolates, were indistinguishable by pulsed-field gel electrophoresis. The study indicates that the occurrence and spread of QAC-resistant S. aureus among dairy cows may be a problem that needs further investigation.
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Affiliation(s)
- J Bjorland
- Department of Reproduction and Forensic Medicine, National Veterinary Institute, Oslo, Norway.
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32
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Sidhu MS, Langsrud S, Holck A. Disinfectant and antibiotic resistance of lactic acid bacteria isolated from the food industry. Microb Drug Resist 2001; 7:73-83. [PMID: 11310806 DOI: 10.1089/107662901750152846] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Quaternary ammonium compounds (QACs) are widely used as disinfectant in medical and food environments. There is a growing concern about the increasing incidence of disinfectant-resistant microorganisms from food. Disinfectant-resistant lactic acid bacteria (LAB) may survive disinfection and cause spoilage problems. Moreover, resistant LAB may potentially act as a reservoir for resistance genes. A total number of 320 LAB from food industry and meat were screened for resistance to the QAC benzalkonium chloride (BC). Out of 320 strains, five strains (1.5%) were considered to be resistant and 56 (17.5%) were tolerant to BC. The resistant strains were isolated from food processing equipment after disinfection. The resistant, tolerant, and some sensitive control bacteria were examined for susceptibility to 18 different antibiotics, disinfectants, and dyes using disc agar diffusion test and microdilution method. Little systematic cross-resistance between BC and any of the antimicrobial agents tested were detected except for gentamycin and chlorhexidine. A BC-tolerant strain was much easier to adapt to higher levels of BC as compared to a BC-sensitive strain. No known gram-positive QAC resistance genes (qacA/B, qacC, qacG, and qacH) were detected in the BC-resistant strains. Identification to species level of the BC-resistant isolates was carried out by comparative analysis of 16S-rDNA sequencing. In conclusion, resistance to BC is not frequent in LAB isolated from food and food environments. Resistance may occur after exposure to BC. The BC resistant isolates showed no cross-resistance with other antimicrobial compounds, except for gentamycin and chlorhexidine. Nevertheless, BC-resistant LAB may be isolated after disinfection and may contribute to the dissemination of resistance.
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Affiliation(s)
- M S Sidhu
- MATFORSK, Norwegian Food Research Institute, As.
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33
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Aase B, Sundheim G, Langsrud S, Rørvik LM. Occurrence of and a possible mechanism for resistance to a quaternary ammonium compound in Listeria monocytogenes. Int J Food Microbiol 2000; 62:57-63. [PMID: 11139022 DOI: 10.1016/s0168-1605(00)00357-3] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In a study of 200 Listeria monocytogenes isolates, 10% were determined to be resistant to benzalkonium chloride (BC). Serial subcultivation of initially BC sensitive (BC(S)) and BC resistant (BC(R)) isolates in sublethal concentrations of BC resulted in enhanced and approximately equal resistance of all strains to the compound. Fifty per cent of the BC(R) isolates showed resistance to ethidium bromide (EB) as well. A proton motive force (pmf)-dependent efflux of EB was demonstrated in BC(R) isolates, and in originally sensitive strains adapted to grow in BC. This efflux was not found in BC(S) strains. The result indicate that BC can induce a broad resistance mechanism based on a pmf-driven efflux pump. There was no indication that this type of resistance was related to resistance to antibiotics.
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Affiliation(s)
- B Aase
- The Norwegian School of Veterinary Science, Oslo
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Heir E, Sundheim G, Holck AL. Identification and characterization of quaternary ammonium compound resistant staphylococci from the food industry. Int J Food Microbiol 1999; 48:211-9. [PMID: 10443540 DOI: 10.1016/s0168-1605(99)00044-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The distribution of known genes conferring resistance to quaternary ammonium compounds (QACs) among different species of staphylococci isolated from the food industry was investigated. Twenty-four isolates hosting one of the genes qacA/qacB, smr, qacG or qacH, were subjected to species identification. Species determination was performed by biochemical analyses (API STAPH), comparative 16S rDNA sequence analysis and tDNA intergenic spacer length polymorphism analysis. Good correlation was obtained between the different methods. The isolates belonged to six different species of coagulase-negative Staphylococcus. The most commonly found species were Staphylococcus epidermidis and Staphylococcus saprophyticus. The results also indicated the possible spread of specific isolates of staphylococci which may reflect the dominance of certain strains in environments were QACs are used on a regular basis. The isolates were further characterized by the resistance phenotype to antimicrobial agents including antibiotics and disinfectants. Resistance to ampicillin, penicillin G and dyes was prevalent in strains harbouring the qacA or qacB genes, features also common among clinical staphylococci containing qacA/qacB. One QAC resistant strain harbouring the smr gene showed resistance to ampicillin, penicillin, tetracycline, erythromycin and trimethoprim. No enterotoxin production was detected among the QAC resistant strains.
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Affiliation(s)
- E Heir
- MATFORSK, Norwegian Food Research Institute, As, Norway.
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Heir E, Sundheim G, Holck AL. The qacG gene on plasmid pST94 confers resistance to quaternary ammonium compounds in staphylococci isolated from the food industry. J Appl Microbiol 1999; 86:378-88. [PMID: 10196743 DOI: 10.1046/j.1365-2672.1999.00672.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The 2.3 kb resistance plasmid pST94 revealed a new gene (qacG) encoding resistance to benzalkonium chloride (BC), a commonly used quaternary ammonium disinfectant, and the intercalating dye ethidium bromide (Eb) in staphylococci isolated from the food industry. The 107 amino acid QacG protein showing 69.2% identity to the staphylococcal multi-drug resistance protein Smr is a new member of the small multi-drug resistance (SMR) protein family. QacG conferred resistance via proton dependent efflux. An additional ORF on pST94 encoded a protein with extensive similarity to replication proteins of other Gram-positive bacteria. Gene constructs containing the qacG and smr gene region combined with the smr or qacG promoter, respectively, indicated that QacG is more efficient than Smr and that qacG has a weaker promoter. Resistant qacG-containing cells could be adapted to withstand higher concentrations of BC. Adapted qacG-containing cells showed increased resistance mainly to BC. In contrast, adaptation of sensitive cells showed cross-resistance development to a range of compounds. Induction of proton-dependent efflux was observed for BC-adapted staphylococci cells not containing qacG. The ability of sublethal concentrations of BC to develop cross-resistance and induce efflux mechanisms could be of practical significance; it should be considered before use of any new disinfectant and in the design of better disinfection procedures.
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Affiliation(s)
- E Heir
- MATFORSK, Norwegian Food Research Institute, As, Norway.
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Heir E, Sundheim G, Holck AL. The Staphylococcus qacH gene product: a new member of the SMR family encoding multidrug resistance. FEMS Microbiol Lett 1998; 163:49-56. [PMID: 9631545 DOI: 10.1111/j.1574-6968.1998.tb13025.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The prevalence of disinfectant-resistant food-related microorganisms is of concern to the food industry. The Staphylococcus saprophyticus strain ST2H6 isolated from a poultry processing plant contained a 2.4-kb plasmid (p2H6) harbouring qacH, which encodes resistance to disinfectants based on quaternary ammonium compounds. The complete p2H6 nucleotide sequence revealed an open reading frame encoding a putative protein of 107 amino acid residues with strong similarity to members of the small multidrug resistance protein family. QacH also conferred high-level ethidium bromide resistance and low-level proflavine resistance and thus differed phenotypically from the similar proteins Smr and QacG. Fluorimetry indicated that the high-level ethidium bromide resistance was due to improved efflux energised by the proton motive force. Site-directed mutagenesis substituting the Asp-24 residue with Glu-24 had no effect on resistance characteristics. An additional open reading frame on p2H6 encoded a putative protein with similarity to rolling circle replication proteins.
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Affiliation(s)
- E Heir
- MATFORSK, Norwegian Food Research Institute, As, Norway.
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Langsrud S, Sundheim G. Flow cytometry for rapid assessment of viability after exposure to a quaternary ammonium compound. J Appl Microbiol 1996. [DOI: 10.1111/j.1365-2672.1996.tb01934.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Langsrud S, Sundheim G. Flow cytometry for rapid assessment of viability after exposure to a quaternary ammonium compound. THE JOURNAL OF APPLIED BACTERIOLOGY 1996; 81:411-8. [PMID: 8896352 DOI: 10.1111/j.1365-2672.1996.tb03527.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The use of flow cytometry to rapidly assess the viability of Pseudomonas spp. and Staphylococcus spp. after exposure to a quaternary ammonium compound (QAC) was investigated using rhodamine 123 (Rh 123), Stain A (LIVE Stain) accumulating in viable but not in dead cells (Live/Dead Baclight bacterial viability kit, Molecular Probes Inc., Eugene, OR, USA), and Sytox green (Molecular Probes) accumulating in dead but not viable cells. Staining conditions were optimized for each stain. The fraction of viable cells after exposure to benzalkonium chloride was determined by using the three staining techniques and colony counts on agar medium. For all Staphylococcus spp. tested there was a high correlation the methods based on flow cytometry and colony counts irrespective of which stain was used. Although viable, all Pseudomonas spp. tested accumulated Rh 123 poorly and about 30% failed to accumulate LIVE stain as well. However, the correlation between colony counts and Sytox green labelling of Pseudomonas spp. was high. Our results indicate that flow cytometry together with live or dead cell labelling can be used to study the bactericidal effect of QACs. The methods based on LIVE stain and Sytox green were simpler and less time consuming than Rh 123 labelling. Only Sytox green could be used with all strains of Staphylococcus and Pseudomonas tested.
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Affiliation(s)
- S Langsrud
- MATFORSK, Norwegian Food Research Institute, As, Norway
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Heir E, Sundheim G, Holck AL. Resistance to quaternary ammonium compounds in Staphylococcus spp. isolated from the food industry and nucleotide sequence of the resistance plasmid pST827. THE JOURNAL OF APPLIED BACTERIOLOGY 1995; 79:149-56. [PMID: 7592110 DOI: 10.1111/j.1365-2672.1995.tb00928.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The complete nucleotide sequence of the 2.8 kb plasmid pST827 involved in resistance to the quaternary ammonium compound (QAC) benzalkonium chloride in meat-associated staphylococci was determined. An open reading frame (ORF) similar to the QAC resistance genes qacC, ebr and smr previously reported from clinical staphylococcal strains was identified (qacC'). In addition an ORF coding for a protein (Rep827) showing extensive homology to reported replication proteins of Gram-positive organisms was found. The occurrence of known QAC resistance gene (qacA-C) among staphylococcal strains isolated from food processing plants was studied by hybridization analysis. Of 191 isolates, 25 were resistant to benzalkonium chloride. Five of these gave no hybridization signals to probes specific for qacA-C. Further hybridization analysis indicated that pST827 or closely related plasmids are widespread among QAC-resistant staphylococcal strains. The finding of resistant staphylococci in different areas of the food processing industry indicates that QAC resistance is a potential problem in the food processing industry.
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Affiliation(s)
- E Heir
- MATFORSK, Norwegian Food Research Institute, As
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