Identification and Transferability of Tetracycline Resistance in Streptococcus thermophilus during Milk Fermentation, Storage, and Gastrointestinal Transit

The existence of antibiotic-resistant bacteria in food products, particularly those carrying acquired resistance genes, has increased concerns about the transmission of these genes from beneficial microbes to human pathogens. In this study, we evaluated the antibiotic resistance-susceptibility patterns of 16 antibiotics in eight S. thermophilus strains, whose genome sequence is available, using phenotypic and genomic approaches. The minimal inhibitory concentration values collected revealed intermediate resistance to aminoglycosides, whereas susceptibility was detected for different classes of β-lactams, quinolones, glycopeptide, macrolides, and sulfonamides in all strains. A high tetracycline resistance level has been detected in strain M17PTZA496, whose genome analysis indicated the presence of the tet(S) gene and the multidrug and toxic compound extrusion (MATE) family efflux pump. Moreover, an in-depth genomic analysis revealed genomic islands and an integrative and mobilizable element (IME) in the proximity of the gene tet(S). However, despite the presence of a prophage, genomic islands, and IME, no horizontal gene transfer was detected to Lactobacillus delbrueckii subsp. lactis DSM 20355 and Lactobacillusrhamnosus GG during 24 h of skim milk fermentation, 2 weeks of refrigerated storage, and 4 h of simulated gastrointestinal transit.

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Drug Resistance Determinants in Clinical Isolates of Enterococcus faecalis in Bangladesh: Identification of Oxazolidinone Resistance Gene optrA in ST59 and ST902 Lineages

Microorganisms ◽

10.3390/microorganisms8081240 ◽

2020 ◽

Vol 8 (8) ◽

pp. 1240

Author(s):

Sangjukta Roy ◽

Meiji Soe Aung ◽

Shyamal Kumar Paul ◽

Salma Ahmed ◽

Nazia Haque ◽

...

Keyword(s):

Drug Resistance ◽

Resistance Gene ◽

Enterococcus Faecalis ◽

Acquired Resistance ◽

Tetracycline Resistance ◽

Clinical Isolates ◽

Multiple Drug ◽

Resistance Level ◽

Resistance Determinants ◽

High Level

Enterococcus faecalis is one of the major causes of urinary tract infection, showing acquired resistance to various classes of antimicrobials. The objective of this study was to determine the prevalence of drug resistance and its genetic determinants for E. faecalis clinical isolates in north-central Bangladesh. Among a total of 210 E. faecalis isolates, isolated from urine, the resistance rates to erythromycin, levofloxacin, and gentamicin (high level) were 85.2, 45.7, and 11.4%, respectively, while no isolates were resistant to ampicillin, vancomycin and teicoplanin. The most prevalent resistance gene was erm(B) (97%), and any of the four genes encoding aminoglycoside modifying enzyme (AME) were detected in 99 isolates (47%). The AME gene aac(6′)-Ie-aph(2”)-Ia was detected in 46 isolates (21.9%) and was diverse in terms of IS256-flanking patterns, which were associated with resistance level to gentamicin. Tetracycline resistance was ascribable to tet(M) (61%) and tet(L) (38%), and mutations in the quinolone resistance-determining region of both GyrA and ParC were identified in 44% of isolates. Five isolates (2.4%) exhibited non-susceptibility to linezolide (MIC, 4 μg/mL), and harbored the oxazolidinone resistance gene optrA, which was located in a novel genetic cluster containing the phenicol exporter gene fexA. The optrA-positive isolates belonged to ST59, ST902, and ST917 (CC59), while common lineages of other multiple drug-resistant isolates were ST6, ST28, CC16, and CC116. The present study first revealed the prevalence of drug resistance determinants of E. faecalis and their genetic profiles in Bangladesh.

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Contribution of the CmeABC Efflux Pump to Macrolide and Tetracycline Resistance in Campylobacter jejuni

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01592-06 ◽

2007 ◽

Vol 51 (9) ◽

pp. 3212-3216 ◽

Cited By ~ 47

Author(s):

Amera Gibreel ◽

Nicole M. Wetsch ◽

Diane E. Taylor

Keyword(s):

Campylobacter Jejuni ◽

Target Gene ◽

Efflux Pump ◽

Acquired Resistance ◽

Tetracycline Resistance ◽

Macrolide Resistance ◽

23S Rrna

ABSTRACT We investigated the involvement of the CmeABC efflux pump in acquired resistance of Campylobacter jejuni to macrolides and tetracycline. Inactivation of the cmeB gene had no effect on macrolide resistance when all copies of the target gene carried an A2074C mutation. In contrast, the CmeABC pump significantly contributed to macrolide resistance when two or three copies of the 23S rRNA had an A2075G transition. Inactivation of the cmeB gene led to restoration of tetracycline susceptibility in the isolates examined. Complete susceptibility to tetracycline or macrolides, however, was not restored when phenylalanine-arginine β-naphthylamide was used. These data confirm contribution of the CmeABC efflux pump to acquired resistance of Campylobacter jejuni to tetracycline and macrolides.

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Burkholderia ubonensis high-level tetracycline resistance is due to efflux pump synergy involving a novel TetA(64) resistance determinant

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01767-20 ◽

2020 ◽

pp. AAC.01767-20

Author(s):

Nawarat Somprasong ◽

Carina M. Hall ◽

Jessica R. Webb ◽

Jason W. Sahl ◽

David M. Wagner ◽

...

Keyword(s):

Burkholderia Cepacia ◽

Efflux Pump ◽

Tetracycline Resistance ◽

Major Facilitator Superfamily ◽

Resistance Determinant ◽

Chromosome 1 ◽

Human Pathogens ◽

Clinically Significant ◽

Major Facilitator ◽

High Level

Burkholderia ubonensis, a non-pathogenic soil bacterium belonging to the Burkholderia cepacia complex (Bcc), is highly resistant to some clinically significant antibiotics. The concern is that B. ubonensis may serve as a resistance reservoir for Bcc or B. pseudomallei complex (Bpc) organisms that are opportunistic human pathogens. Using a B. ubonensis strain highly resistant to tetracycline (MIC ≥256 μg/ml), we identified and characterized tetA(64) that encodes a novel tetracycline-specific efflux pump of the major facilitator superfamily. TetA(64) and associated TetR(64) regulator expression is induced by tetracyclines. Although TetA(64) is the primary tetracycline and doxycycline resistance determinant, maximum tetracycline and doxycycline resistance requires synergy between TetA(64) and the non-specific AmrAB-OprA resistance nodulation cell division efflux pump. TetA(64) does not efflux minocycline, tigecycline and eravacycline. Comprehensive screening of genome sequences showed that TetA(64) is unequally distributed in the Bcc and absent from the Bpc. It is present in some major cystic fibrosis pathogens, like B. cenocepacia, but absent from others like B. multivorans. The tetR(64)-tetA(64) genes are located in a region of chromosome 1 that is highly conserved in Burkholderia. Because there is no evidence for transposition, the tetR(64)-tetA(64) genes may have been acquired by homologous recombination after horizontal gene transfer. Although Burkholderia species contain a resident multi-component efflux pump that allows them to respond to tetracyclines up to a certain concentration, the acquisition of the single-component TetA(64) by some species likely provides the synergy that these bacteria need to defend against high tetracycline concentrations in niche environments.

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Ready-to-Eat Shrimp as an International Vehicle of Antibiotic-Resistant Bacteria†

Journal of Food Protection ◽

10.4315/0362-028x-68.11.2395 ◽

2005 ◽

Vol 68 (11) ◽

pp. 2395-2401 ◽

Cited By ~ 69

Author(s):

GIANNA M. DURÁN ◽

DOUGLAS L. MARSHALL

Keyword(s):

Shigella Flexneri ◽

Bacterial Species ◽

Acquired Resistance ◽

Animal Origin ◽

Resistant Bacteria ◽

Grocery Stores ◽

Human Pathogens ◽

Antibiotic Resistant Bacteria ◽

Potential Health ◽

Antibiotic Resistant

The occurrence of antibiotic-resistant bacteria in foods of animal origin is a potential health threat because resistance can be transferred among bacteria, and antibiotic-resistant pathogens may not respond to antibiotic treatments. Thirteen brands of ready-to-eat shrimp representing four countries of origin were obtained from local grocery stores. Total heterotrophic plate counts were determined, and antibiotic-resistant bacteria were isolated. Total heterotrophic colony counts ranged from 3.3 to 5.6 log CFU/g, which was within approved quality limits. A total of 1,564 isolates representing 162 bacterial species were recovered during screening of resistance to 10 antibiotics: ampicillin, ceftriaxone, chloramphenicol, clindamycin, erythromycin, nalidixic acid, streptomycin, tetracycline, trimethoprim, and vancomycin. Six hundred fifty-seven (42%) of the isolates and 131 (81%) of the species had acquired resistance to antibiotics. Numerous resistant human pathogens were isolated, including Escherichia coli, Enterococcus spp., Salmonella, Shigella flexneri, Staphylococcus spp., and Vibrio spp. Nonresistant Yersinia spp. also were isolated. Ready-to-eat shrimp is sold with instructions to thaw the product before serving, which may result in consumer exposure to antibiotic-resistant bacteria. Widespread trade of this product provides an avenue for international dissemination of antibiotic-resistant pathogens.

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Two Different Tetracycline Resistance Mechanisms, Plasmid-Carried tet(L) and Chromosomally Located Transposon-Associated tet(M), Coexist in Lactobacillus sakei Rits 9

Applied and Environmental Microbiology ◽

10.1128/aem.01463-07 ◽

2008 ◽

Vol 74 (5) ◽

pp. 1394-1401 ◽

Cited By ~ 49

Author(s):

Mohammed Salim Ammor ◽

Miguel Gueimonde ◽

Morten Danielsen ◽

Monique Zagorec ◽

Angela H. A. M. van Hoek ◽

...

Keyword(s):

Efflux Pump ◽

Expression Patterns ◽

Starter Culture ◽

Meat Products ◽

Tetracycline Resistance ◽

Raw Milk ◽

Lactobacillus Sakei ◽

M Gene ◽

Resistance Level ◽

Gene Coding

ABSTRACT Lactobacillus sakei is extensively used as functional starter culture in fermented meat products. One of the safety criteria of a starter culture is the absence of potentially transferable antibiotic resistance determinants. However, tetracycline-resistant L. sakei strains have already been observed. In this paper, we show that tetracycline resistance in L. sakei Rits 9, a strain isolated from Italian Sola cheese made from raw milk, is mediated by a transposon-associated tet(M) gene coding for a ribosomal protection protein and a plasmid-carried tet(L) gene coding for a tetracycline efflux pump. pLS55, the 5-kb plasmid carrying the tet(L) gene, is highly similar to the pMA67 plasmid recently described for Paenibacillus larvae, a species pathogenic to honeybees. pLS55 could be transferred by electroporation into the laboratory strain L. sakei 23K. While the L. sakei 23K transformant containing pLS55 displayed an intermediate tetracycline resistance level (MIC, <32 μg/ml), L. sakei Rits 9, containing both tetracycline-resistant determinants, had a MIC of <256 μg/ml, suggesting that Tet L and Tet M confer different levels of resistance in L. sakei. Remarkably, in the absence of tetracycline, a basal expression of both genes was detected for L. sakei Rits 9. In addition, subinhibitory concentrations of tetracycline affected the expression patterns of tet(M) and tet(L) in different ways: the expression of tet(M) was induced only at high tetracycline concentrations, whereas the expression of tet(L) was up-regulated at lower concentrations. This is the first time that two different mechanisms conferring resistance to tetracycline are characterized for the same strain of a lactic acid bacterium.

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Resistance Mechanisms of Multiresistant Pseudomonas aeruginosa Strains from Germany and Correlation with Hypermutation

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00148-07 ◽

2007 ◽

Vol 51 (11) ◽

pp. 4062-4070 ◽

Cited By ~ 105

Author(s):

B. Henrichfreise ◽

I. Wiegand ◽

W. Pfister ◽

B. Wiedemann

Keyword(s):

Pseudomonas Aeruginosa ◽

Efflux Pump ◽

Acquired Resistance ◽

Resistance Mechanisms ◽

Type Ii ◽

Mechanisms Of Resistance ◽

Resistance Determinants ◽

Class 1 ◽

Mutator Strains ◽

Multiresistant Strains

ABSTRACT In this study, we analyzed the mechanisms of multiresistance for 22 clinical multiresistant and clonally different Pseudomonas aeruginosa strains from Germany. Twelve and 10 strains originated from cystic fibrosis (CF) and non-CF patients, respectively. Overproduction of the efflux systems MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY-OprM was studied. Furthermore, loss of OprD, alterations in type II topoisomerases, AmpC overproduction, and the presence of 25 acquired resistance determinants were investigated. The presence of a hypermutation phenotype was also taken into account. Besides modifications in GyrA (91%), the most frequent mechanisms of resistance were MexXY-OprM overproduction (82%), OprD loss (82%), and AmpC overproduction (73%). Clear differences between strains from CF and non-CF patients were found: numerous genes coding for aminoglycoside-modifying enzymes and located, partially in combination with β-lactamase genes, in class 1 integrons were found only in strains from non-CF patients. Furthermore, multiple modifications in type II topoisomerases conferring high quinolone resistance levels and overexpression of MexAB-OprM were exclusively detected in multiresistant strains from non-CF patients. Correlations of the detected phenotypes and resistance mechanisms revealed a great impact of efflux pump overproduction on multiresistance in P. aeruginosa. Confirming previous studies, we found that additional, unknown chromosomally mediated resistance mechanisms remain to be determined. In our study, 11 out of 12 strains and 3 out of 10 strains from CF patients and non-CF patients, respectively, were hypermutable. This extremely high proportion of mutator strains should be taken into consideration for the treatment of multiresistant P. aeruginosa.

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Genetic but No Phenotypic Associations between Biocide Tolerance and Antibiotic Resistance in Escherichia coli from German Broiler Fattening Farms

Microorganisms ◽

10.3390/microorganisms9030651 ◽

2021 ◽

Vol 9 (3) ◽

pp. 651

Author(s):

Alice Roedel ◽

Szilvia Vincze ◽

Michaela Projahn ◽

Uwe Roesler ◽

Caroline Robé ◽

...

Keyword(s):

Escherichia Coli ◽

Antibiotic Resistance ◽

Acquired Resistance ◽

Antibiotic Resistance Genes ◽

Animal Husbandry ◽

Metal Resistance ◽

Resistant Bacteria ◽

Virulence Determinants ◽

Phylogenetic Distribution ◽

Resistance Determinants

Biocides are frequently applied as disinfectants in animal husbandry to prevent the transmission of drug-resistant bacteria and to control zoonotic diseases. Concerns have been raised, that their use may contribute to the selection and persistence of antimicrobial-resistant bacteria. Especially, extended-spectrum β-lactamase- and AmpC β-lactamase-producing Escherichia coli have become a global health threat. In our study, 29 ESBL-/AmpC-producing and 64 NON-ESBL-/AmpC-producing E.coli isolates from three German broiler fattening farms collected in 2016 following regular cleaning and disinfection were phylogenetically characterized by whole genome sequencing, analyzed for phylogenetic distribution of virulence-associated genes, and screened for determinants of and associations between biocide tolerance and antibiotic resistance. Of the 30 known and two unknown sequence types detected, ST117 and ST297 were the most common genotypes. These STs are recognized worldwide as pandemic lineages causing disease in humans and poultry. Virulence determinants associated with extraintestinal pathogenic E.coli showed variable phylogenetic distribution patterns. Isolates with reduced biocide susceptibility were rarely found on the tested farms. Nine isolates displayed elevated MICs and/or MBCs of formaldehyde, chlorocresol, peroxyacetic acid, or benzalkonium chloride. Antibiotic resistance to ampicillin, trimethoprim, and sulfamethoxazole was most prevalent. The majority of ESBL-/AmpC-producing isolates carried blaCTX-M (55%) or blaCMY-2 (24%) genes. Phenotypic biocide tolerance and antibiotic resistance were not interlinked. However, biocide and metal resistance determinants were found on mobile genetic elements together with antibiotic resistance genes raising concerns that biocides used in the food industry may lead to selection pressure for strains carrying acquired resistance determinants to different antimicrobials.

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Resistance to nitrofurantoin is an indicator of extensive drug-resistant (XDR) Enterobacteriaceae

Journal of Medical Microbiology ◽

10.1099/jmm.0.001347 ◽

2021 ◽

Vol 70 (4) ◽

Author(s):

Balaram Khamari ◽

Prakash Kumar ◽

Bulagonda Eswarappa Pradeep

Keyword(s):

Antimicrobial Agents ◽

Efflux Pump ◽

Treatment Options ◽

Strong Association ◽

Multidrug Resistant ◽

Resistance Mechanisms ◽

Resistant Bacteria ◽

Drug Resistant ◽

Content Type ◽

Link Type

Introduction. Nitrofurantoin is one of the preferred antibiotics in the treatment of uropathogenic multidrug-resistant (MDR) infections. However, resistance to nitrofurantoin in extensively drug-resistant (XDR) bacteria has severely limited the treatment options. Gap statement. Information related to co-resistance or collateral sensitivity (CS) with reference to nitrofurantoin resistant bacteria is limited. Aim. To study the potential of nitrofurantoin resistance as an indicator of the XDR phenotype in Enterobacteriaceae . Methods. One hundred (45 nitrofurantoin-resistant, 21 intermediately resistant and 34 nitrofurantoin-susceptible) Enterobacteriaceae were analysed in this study. Antibiotic susceptibility testing (AST) against nitrofurantoin and 17 other antimicrobial agents across eight different classes was performed by using the Vitek 2.0 system. The isolates were screened for the prevalence of acquired antimicrobial resistance (AMR) and efflux pump genes by PCR. Results. In total, 51 % of nitrofurantoin-resistant and 28 % of intermediately nitrofurantoin resistant isolates exhibited XDR characteristics, while only 3 % of nitrofurantoin-sensitive isolates were XDR (P=0.0001). Significant co-resistance was observed between nitrofurantoin and other tested antibiotics (β-lactam, cephalosporin, carbapenem, aminoglycoside and tetracycline). Further, the prevalence of AMR and efflux pump genes was higher in the nitrofurantoin-resistant strains compared to the susceptible isolates. A strong association was observed between nitrofurantoin resistance and the presence of bla PER-1, bla NDM-1, bla OXA-48, ant(2) and oqxA-oqxB genes. Tigecycline (84 %) and colistin (95 %) were the only antibiotics to which the majority of the isolates were susceptible. Conclusion. Nitrofurantoin resistance could be an indicator of the XDR phenotype among Enterobacteriaceae , harbouring multiple AMR and efflux pump genes. Tigecycline and colistin are the only antibiotics that could be used in the treatment of such XDR infections. A deeper understanding of the co-resistance mechanisms in XDR pathogens and prescription of AST-based appropriate combination therapy may help mitigate this problem.

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Antimicrobial resistance of fecal indicators in disinfected wastewater

Water Science & Technology ◽

10.2166/wst.2011.769 ◽

2011 ◽

Vol 64 (12) ◽

pp. 2352-2361 ◽

Cited By ~ 18

Author(s):

A. Luczkiewicz ◽

K. Jankowska ◽

R. Bray ◽

E. Kulbat ◽

B. Quant ◽

...

Keyword(s):

Antimicrobial Agents ◽

Treatment Plant ◽

Tetracycline Resistance ◽

Pilot Scale ◽

Resistant Bacteria ◽

Secondary Effluent ◽

Fecal Indicators ◽

Extended Spectrum Beta Lactamase ◽

E Coli ◽

Operation Conditions

The main objective of the study was to assess the potential of three systems (UV irradiation, ozonation, and micro/ultrafiltration) operated in a pilot scale in removal of antimicrobial-resistant fecal bacteria from secondary effluent of the local wastewater treatment plant (700,000 population equivalent). The effectiveness of the processes was analysed using the removal ratio of fecal indicators (Escherichia coli and Enterococcus spp.). The susceptibility of fecal indicators to antimicrobial agents important in human therapy was examined. Resistance to nitrofurantoin and erythromycin was common among enterococci and followed by resistance to fluoroquinolones and tetracycline. Resistance to high-level aminoglycosides and glycopeptides was also observed. E. coli isolates were most frequently resistant to penicillins and tetracycline. The extended-spectrum beta-lactamase-producing E. coli was detected once, after ozonation. Substantial attention should be paid to the E. coli and enterococci resistant to three or more chemical classes of antimicrobials (MAR), which in general constituted up to 15 and 49% of the tested isolates, respectively. Although the applied methods were effective in elimination of fecal indicators (removal efficiency up to 99.99%), special attention has to be paid to the application of sufficient disinfection and operation conditions to avoid selection of antimicrobial resistant bacteria.

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