An Uncommon ST1224 NDM-1-Producing Klebsiella pneumoniae Isolated from the Bloodstream of a Leukemia Patient in China

Chemotherapy ◽  
2017 ◽  
Vol 62 (4) ◽  
pp. 262-268 ◽  
Author(s):  
Xiaoxiao Zhang ◽  
Jia Du ◽  
Cui Zhou ◽  
Jianming Cao ◽  
Hong Lu ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Southern Blot ◽  
Clinical Data ◽  
Ethylenediaminetetraacetic Acid ◽  
Resistant Bacteria ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Combination Drug ◽  
Leukemia Patient ◽  
Resistant Genes

Aims: This study aimed to analyze the clinical data and characteristics of an NDM-1 (New Delhi metallo-β-lactamase-1)-producing Klebsiella pneumoniae isolated from the bloodstream of a leukemia patient. Materials and Methods: A retrospective analysis was used for the clinical data of the patient. The modified Hodge test (MHT) and ethylenediaminetetraacetic acid (EDTA)-disk synergy test were used for detecting metallo-β-lactamase. Antibiotic resistance was determined using the agar dilution method. PCR was used to identify resistance genes. S1-PFGE (S1 nuclease/pulsed-field gel electrophoresis) and Southern blot hybridization were performed to determine the location of blaNDM-1. A conjugation experiment was used to confirm the transferable characteristics of the resistant genes. Multilocus sequence typing (MLST) was also performed. Results: The patient developed bloodstream infections caused by this NDM-1-producing strain and died due to worsening of the condition. The strain was highly resistant to β-lactam antibiotics and coharbored blaNDM-1, qnrB, and blaCTX-M-9 genes. Southern blot confirmed that blaNDM-1 was located on a plasmid of approximately 55 kb and could be transferred to Escherichia coli J53. MLST analysis showed that this strain belonged to an uncommon sequence type ST1224. Conclusion: The coexistence of various resistant genes is the mechanism for resistance to most antibiotics. Additionally, infections caused by multi-drug resistant bacteria increase the mortality of patients with immunodeficiency, which alerts clinicians to establish a rational and effective combination drug therapy.

scholarly journals Plasmid mediated colistin resistant mcr-1 and co-existence of OXA-48 among Escherichia coli from clinical and poultry isolates: first report from Nepal

Gut Pathogens ◽  
2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Bijaya Muktan ◽  
Upendra Thapa Shrestha ◽  
Binod Dhungel ◽  
Bagish Chandra Mishra ◽  
Nabaraj Shrestha ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Gene ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Colistin Resistance ◽  
Clinical Specimens ◽  
E Coli ◽  
Resistant Genes ◽  
Rectal Swabs

Abstract Background Plasmid-mediated resistance to the last-resort drugs: carbapenems and colistin is an emerging public health threat. The studies on the prevalence and co-expression of resistant genes among livestock and human pathogens are rare in Nepal. This is the first study in Nepal exploring the prevalence and co-existence of colistin resistance gene, mcr-1 along with carbapenemase resistance gene, OXA-48 in Escherichia coli isolated from poultry and clinical specimens. Methods A total of 240 rectal swabs from chickens of five different poultry farms of Kathmandu valley and 705 mid-stream urine samples from human subjects attending Kantipur Hospital, Kathmandu were collected between August, 2018 and March, 2019. Rectal swabs and urine specimens were cultured. E. coli isolated from the specimens were screened for antimicrobial susceptibility testing (AST) using disk diffusion method’. Minimum inhibitory concentration (MIC) of colistin was determined by agar dilution method using 0.5 µg/ml to 32 µg/ml. The E. coli isolates were first screened for mcr-1 followed by screening for OXA-48 genes using conventional Polymerase chain reaction (PCR). Results Of the total samples analyzed, E. coli was isolated from 31.7% (76/240) of poultry and 7.9% (56/705) of clinical specimens. In AST, 80% (61/76) of E. coli from poultry and 79% (44/56) from clinical specimens were MDR. The phenotypic prevalence of colistin resistance in poultry specimens were 31.6% (24/76) and clinical specimens were 21.4% (12/56). In PCR assay, 27.6% (21/76) of poultry and 19.6% (11/56) of clinical isolates had colistin resistant mcr-1 gene. MICs value of E. coli isolates ranged from 4 to 32 (µg/ml) in both clinical and poultry isolates. Prevalence of co-existing carbapenem resistance gene, OXA-48, among colistin resistant mcr-1 positive isolates was 38% (8/21) in poultry specimens and 18.2% (2/11) in clinical specimens. Conclusions The high prevalence of colistin and carbapenem resistant genes, and their co-existence in plasmid DNA of E. coli isolates in this study suggests the possible spread to other animal, human and environmental pathogens. Molecular methods in addition to the conventional diagnostics in laboratories can help in early diagnosis, effective management and control of their potential transmission.

scholarly journals Potential spread of multidrug-resistant coagulase-negative staphylococci through healthcare waste

2015 ◽  
Vol 9 (01) ◽  
pp. 029-034 ◽  
Author(s):  
Thiago César Nascimento ◽  
Vânia Lúcia Da Silva ◽  
Alessandra Barbosa Ferreira-Machado ◽  
Cláudio Galuppo Diniz
Keyword(s):  
Meca Gene ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Coagulase Negative Staphylococcus ◽  
Coagulase Negative Staphylococci ◽  
Healthcare Waste ◽  
Sanitary Landfills ◽  
Rdna Sequencing

Introduction: Healthcare waste (HCW) might potentially harbor infective viable microorganisms in sanitary landfills. We investigated the antimicrobial susceptibility patterns and the occurrence of the mecA gene in coagulase-negative Staphylococcus strains (CoNS) recovered from the leachate of the HCW in an untreated sanitary landfill. Methodology: Bacterial identification was performed by physiological and molecular approaches, and minimum inhibitory concentrations (MICs) of antimicrobial drugs were determined by the agar dilution method according to CLSI guidelines. All oxacillin-resistant bacteria were screened for the mecA gene. Results: Out of 73 CoNS, seven different species were identified by 16S rDNA sequencing: Staphylococcus felis (64.4%; n = 47), Staphylococcus sciuri (26.0%; n = 19), Staphylococcus epidermidis (2.7%; n = 2), Staphylococcus warneri (2.7%; n = 2), Staphylococcus lentus (1.4%; n = 1), Staphylococcus saprophyticus (1.4%; n = 1), and Staphylococcus haemolyticus (1.4%; n = 1). Penicillin was the least effective antimicrobial (60.3% of resistance; n = 44) followed by erythromycin (39.8%; n = 29), azithromycin (28.8%; n = 21), and oxacillin (16.5%; n = 12). The most effective drug was vancomycin, for which no resistance was observed, followed by gentamicin and levofloxacin, for which only intermediate resistance was observed (22%, n = 16 and 1.4%, n = 1, respectively). Among the oxacillin-resistant strains, the mecA gene was detected in two isolates. Conclusions: Considering the high antimicrobial resistance observed, our results raise concerns about the survival of putative bacterial pathogens carrying important resistance markers in HCW and their environmental spread through untreated residues discharged in sanitary landfills.

scholarly journals Antibacterial Activity of Guyabano, Ulasimang Bato, Sambong, and Tsaang Gubat Leaf Extracts against Common Drug-resistant Bacteria

2020 ◽  
Vol 54 (1) ◽  
Author(s):  
Cecilia C. Maramba-Lazarte ◽  
Lolita L. Cavinta ◽  
Ma. Carmelita L. Sara
Keyword(s):  
Antibacterial Activity ◽  
Leaf Extract ◽  
Resistant Bacteria ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Moderate Activity ◽  
Alcoholic Extract ◽  
Drug Resistant ◽  
Leaf Extracts ◽  
E Coli

Background. Using plants as antimicrobials has long been a practice of traditional healers and validating these customs may lead to the discovery and development of useful herbal medicines. Objective. This study aimed to determine the antibacterial activity of guyabano, tsaang gubat, sambong, and ulasimang bato against common pathogens. Methods. Aqueous or alcoholic leaf extracts of the different medicinal plants were prepared. The solid agar dilution method was used to determine the MIC of guyabano, tsaang gubat, sambong, and ulasimang bato against common pathogens including Staphylococcus aureus, Echerichia coli, Streptococcus pneumoniae, Hemophilus influenzae, Pseudomonas aeruginosa, Salmonella typhi, and Shigella flexneri. Results. The alcoholic leaf extract of guyabano showed moderate activity against oxacillin-sensitive S. aureus with an MIC of 5-6.3 mg/mL. However, tsaang gubat did not exhibit any antibacterial activity for drug-resistant enteric organisms (S. typhi, S. flexneri, and E. coli) and S. aureus at a concentration of 25 mg/mL. Even at a concentration of 100mg/mL, ulasimang bato failed to show any antibacterial activity against drug-resistant S. aureus, S. pneumonia, H. influenzae, E. coli, and P. aeruginosa. Sambong alcoholic extract had some antibacterial activity against penicillin-resistant S. pneumoniae with an MIC of 12.5 mg/mL. Conclusions. Guyabano alcoholic leaf extract showed moderate antibacterial activity against oxacillin-sensitive S. aureus. Sambong alcoholic extract likewise exhibited inhibitory activity against S. pneumoniae. However, tsaang gubat and ulasimang bato aqueous extracts failed to show significant antibacterial activity for the pathogens tested.

scholarly journals COLISTIN RESISTANCE IN CARBAPENEM-RESISTANT KLEBSIELLA PNEUMONIAE STRAINS

2017 ◽  
Vol 10 (9) ◽  
pp. 70
Author(s):  
Beena Hosdurg Bhaskar ◽  
Shalini Shenoy Mulki ◽  
Sangeeta Joshi ◽  
Ranjeeta Adhikari ◽  
Bhavana Malavalli Venkatesh
Keyword(s):  
Antibiotic Susceptibility ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Ethylenediaminetetraacetic Acid ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Antibiotic Susceptibility Testing ◽  
Carbapenem Resistant

Objective: There is an increasing use of colistin consequent to increase in the infections caused by carbapenem-resistant Klebsiella pneumoniae.The present study was conducted to determine the minimum inhibitory concentration (MIC) of colistin and the resistance pattern of colistin in carbapenem-resistant K. pneumoniae (CRKP) strains in our intensive care unit (ICU).Methods: Antibiotic susceptibility testing for other antimicrobial agents was done by Kirby-Bauer disk diffusion method. MIC of colistin was determined by agar dilution method. The results of antibiotic susceptibility testing were interpreted as per Clinical Laboratory Standard Institute guidelines 2016 and MIC of colistin were interpreted as per European Committee on Antimicrobial susceptibility testing. The carbapenem resistance was phenotypically detected by modified hodge test and imipenem/imipenem ethylenediaminetetraacetic acid disk method.Results: Out of 518 K. pneumoniae, 329 were resistant to carbapenems, and 91 isolates showed resistance to colistin. The MIC of colistin ranged between 4 and >512 ug/ml and MIC90 was 16 ug/L and MIC50 was 4 ug/ml. A majority of the colistin-resistant isolates were found in multidisciplinary ICU (85/91).Conclusion: The emergence of colistin-resistant strains is a major problem due to limited treatment options for infections caused by CRKP carbapenemase producing K. pneumoniae. Colistin should not be used alone, combination therapy should be preferred.

scholarly journals Assessment of antibiotic- and disinfectant-resistant bacteria in hospital wastewater, south Ethiopia: a cross-sectional study

2015 ◽  
Vol 9 (02) ◽  
pp. 149-156 ◽  
Author(s):  
Sintayehu Fekadu ◽  
Yared Merid ◽  
Hunachew Beyene ◽  
Wondu Teshome ◽  
Solomon Gebre-Selassie
Keyword(s):  
Pathogenic Bacteria ◽  
Cross Sectional Study ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Hospital Wastewater ◽  
Sectional Study ◽  
Cross Sectional ◽  
Wide Range

Introduction: Large quantities of antimicrobials are used in hospitals for patient care and disinfection. Antibiotics are partially metabolized and residual quantities reach hospital wastewater, exposing bacteria to a wide range of biocides that could act as selective pressure for the development of resistance. Methodology: A cross-sectional study was conducted between December 2010 and February 2011 on hospital wastewater. A total of 24 composite samples were collected on a weekly basis for bacteriological analysis and susceptibility testing. Indicator organisms and pathogenic and potentially pathogenic bacteria were found and isolated on selective bacteriologic media. Disinfectant activity was evaluated by use-dilution, and minimum inhibitory concentration (MIC) was determined by the agar dilution method. Similarly, antibiotic susceptibility tests were performed using the Kirby-Bauer disk diffusion method. Results: Pathogenic (Salmonella, Shigella, and S. aureus) and potentially pathogenic (E. coli) bacteria were detected from effluents of both hospitals. Dilution demonstrated tincture iodine to be the most effective agent, followed by sodium hypochlorite; the least active was 70% ethanol. MIC for ethanol against S. aureus and Gram-negative rods from Yirgalem Hospital (YAH) showed 4 and 3.5 log reduction, respectively. Salmonella isolates from YAH effluent were resistant to ceftriaxone, tetracycline, and doxycycline. Isolates from Hawassa University Referral Hospital (HURH) effluent were resistant to the above three antibiotics as well as gentamycin. Conclusions: Hospital effluents tested contained antibiotic-resistant bacteria, which are released into receiving water bodies, resulting in a threat to public health.

scholarly journals Evaluation of ceftazidime/avibactam alone and in combination with amikacin, colistin and tigecycline against Klebsiella pneumoniae carbapenemase-producing K. pneumoniae by in vitro time-kill experiment

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258426
Author(s):  
Fangzhou Wang ◽  
Qian Zhou ◽  
Xiuwen Yang ◽  
Yan Bai ◽  
Junchang Cui
Keyword(s):  
Klebsiella Pneumoniae ◽  
Antibacterial Activities ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Klebsiella Pneumoniae Carbapenemase ◽  
Single Drug ◽  
Mueller Hinton ◽  
Mutant Prevention Concentration ◽  
Time Kill

Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) poses a major threat to human health worldwide. Combination therapies of antibiotics with different mechanisms have been recommended in literatures. This study assessed in vitro antibacterial activities and synergistic activities of ceftazidime/avibactam alone and in combinations against KPC-Kp. In total, 70 isolates from 2 hospitals in Beijing were examined in our study. By using the agar dilution method and broth dilution method, we determined the minimum inhibitory concentration (MIC) of candidate antibiotics. Ceftazidime/avibactam demonstrated promising susceptibility against KPC-Kp (97.14%). Synergistic activities testing was achieved by checkerboard method and found ceftazidime/avibactam-amikacin displayed synergism in 90% isolates. Ceftazidime/avibactam-colistin displayed partial synergistic in 43% isolates, and ceftazidime/avibactam-tigecycline displayed indifference in 67% isolates. In time-kill assays, antibiotics at 1-fold MIC were mixed with bacteria at 1 × 105 CFU/ml and Mueller-Hinton broth (MHB). Combinations of ceftazidime/avibactam with amikacin and tigecycline displayed better antibacterial effects than single drug. Ceftazidime/avibactam-colistin combination did not exhibit better effect than single drug. In KPC-Kp infections, susceptibility testing suggested that ceftazidime/avibactam may be considered as first-line choice. However, monotherapy is often inadequate in infection management. Thus, our study revealed that combination therapy including ceftazidime/avibactam colistin and ceftazidime/avibactam tigecycline may benefit than monotherapy in KPC-Kp treatment. Further pharmacokinetic/pharmacodynamic and mutant prevention concentration studies should be performed to optimize multidrug-regimens.

Prevalence of Carbapenemase Genes, qacE, qacEΔ1 and cepA in Multidrug-Resistant Gram-Negative Bacteria with Different Susceptibility to Chlorhexidine

2020 ◽  
Vol 19 (5) ◽  
pp. 49-60
Author(s):  
K. G. Kosyakova ◽  
N. B. Esaulenko ◽  
O. A. Kameneva ◽  
S. P. Kazakov ◽  
A. Y. Dubinina ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Multidrug Resistant ◽  
World Health ◽  
Dynamic Monitoring ◽  
Resistant Bacteria ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Health Organization

Relevance The World Health Organization has provided a list of resistant bacteria that pose the greatest threat to society. Among them, the most important (critically high priority level) are Pseudomonas aeruginosa and Acinetobacter baumannii strains resistant to carbapenems, as well as enterobacteriaceae producing extended spectrum beta-lactamases and carbapenemases.Aim. To conduct a comparative analysis of the sensitivity to chlorhexidine of multiply-resistant gram-negative bacteria, the causative agents of infectious conditions in patients of various medical organizations, and to study the relationship between the presence of resistance genes and the minimum inhibitory concentration of chlorhexidine.Materials & methods. The study included 138 Gram-negative multidrug-resistant strains isolated during 2018–2019 from various clinical specimens. Susceptibility of the isolates to antibiotics were determined using Vitek-2 compact and Phoenix М50, susceptibility to chlorhexidine were determined by agar dilution method. The resistance genes were detected by the real-time PCR method.Results. The lowest level of resistance to chlorhexidine was determined in E. coli strains (MIC90 16 mg/l), other strains were highly resistant: MIC90 of P. aeruginosa and A. baumannii – 128 mg/l, K. pneumoniae, E. cloacae и P. mirabilis – 256 mg/l. The highest frequency of detection of carbapenemase genes observed in K. pneumoniae strains – 56.0% and P. aeruginosa – 48.1%. High prevalence of cepA gene was found out (the strains of enterobacteria – 47.8%, A. baumannii – 42.9%), genes qacE, qacEΔ1 were more often detected in non-fermenting Gram-negative bacteria then in enterobacteria. Conclusion. According to the results of our study, we did not reveal a significant correlation between the presence or absence of resistance genes and MIC of chlorhexidine in Gram-negative bacteria. However, taking into account complex mechanism of the adaptive response of bacteria to the effects of chlorhexidine, and to implement the concept of preventing health care-associated infections, it is proposed to continue dynamic monitoring of the resistance of microorganisms to antiseptics, disinfectants and antibiotics.

scholarly journals Reduced ceftazidime and ertapenem susceptibility due to production of OXA-2 in Klebsiella pneumoniae ST258

2019 ◽  
Vol 74 (8) ◽  
pp. 2203-2208
Author(s):  
Alina Iovleva ◽  
Roberta T Mettus ◽  
Christi L McElheny ◽  
Mustapha M Mustapha ◽  
Daria Van Tyne ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Kinetic Studies ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Class 1 Integron ◽  
E Coli ◽  
Relative Contribution ◽  
Class D ◽  
Class 1 ◽  
Agar Dilution

Abstract Background OXA-2 is a class D β-lactamase that confers resistance to penicillins, as well as narrow-spectrum cephalosporins. OXA-2 was recently reported to also possess carbapenem-hydrolysing activity. Here, we describe a KPC-2-encoding Klebsiella pneumoniae isolate that demonstrated reduced susceptibility to ceftazidime and ertapenem due to production of OXA-2. Objectives To elucidate the role of OXA-2 production in reduced ceftazidime and ertapenem susceptibility in a K. pneumoniae ST258 clinical isolate. Methods MICs were determined by the agar dilution method. WGS was conducted to identify and compare resistance genes between isolates. Expression of KPC-2 was quantified by quantitative RT–PCR and immunoblotting. OXA-2 was expressed in Escherichia coli TOP10, as well as in K. pneumoniae ATCC 13883, to define the relative contribution of OXA-2 in β-lactam resistance. Kinetic studies were conducted using purified OXA-2 enzyme. Results K. pneumoniae 1761 belonged to ST258 and carried both blaKPC-2 and blaOXA-2. However, expression of blaKPC-2 was substantially reduced due to an IS1294 insertion in the promoter region. K. pneumoniae 1761, K. pneumoniae ATCC 13883 and E. coli TOP10 carrying blaOXA-2-harbouring plasmids showed reduced susceptibility to ertapenem and ceftazidime, but meropenem, imipenem and cefepime were unaffected. blaOXA-2 was carried on a 2910 bp partial class 1 integron containing aacA4-blaOXA-2-qacEΔ1-sul1 on an IncA/C2 plasmid, which was not present in the earlier ST258 isolates possessing blaKPC-2 with intact promoters. Hydrolysis of ertapenem by OXA-2 was confirmed using purified enzyme. Conclusions Production of OXA-2 was associated with reduced ceftazidime and ertapenem susceptibility in a K. pneumoniae ST258 isolate.

scholarly journals Antibacterial Activity of Fresh Red and White Onion (Allium cepa) Extract against Some Drug Resistant Bacteria

2019 ◽  
pp. 1-8
Author(s):  
K. Zikora Anyaegbunam ◽  
L. Ogara Amaechi ◽  
C. AnyaegbunamTito ◽  
O. Oniwon Wisdom ◽  
C. Ogechukwu Henrietta ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Allium Cepa ◽  
Antimicrobial Agents ◽  
Resistant Bacteria ◽  
Antibiotics Resistance ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Onion Extract

Antibiotics resistance is currently one of the major challenges in the health care system. The antimicrobial properties of some herbs have been used in the treatment of infectious diseases as well as disinfection of surfaces. This in a way helps overcome microbial resistance arising from indiscriminate use of synthetic antimicrobial agents for similar purpose. Some antibiotic resistant bacteria- Pseudomonas aeruginosa, Staphylococus aureus and Escherichia coli isolated from cooking wares in homes were investigated using agar well diffusion and agar dilution method to test for the antibacterial activity of fresh Allium cepa (onion) extract. All were susceptible to the fresh white and red onion extract except Staphylococus aureus which was susceptible to only the white onion extract. The diameter of zones of inhibition ranged from 2 mm-35 mm. The Minimum Inhibitory Concentration (M. I. C.) and the Minimum Bacterial Concentration (M. B. C.) values of the fresh onion juices against the test bacteria were low ranging from 3.125% v/v – 25.0% v/v. This study indicates that the fresh raw extracts of Allium cepa possess significant antibacterial potency against these antibiotic resistant bacteria.

scholarly journals Characteristics of ciprofloxacin-resistant Enterobacteriaceae isolates recovered from wastewater of an Algerian hospital

2016 ◽  
Vol 10 (07) ◽  
pp. 728-734 ◽  
Author(s):  
Lynda Anssour ◽  
Yamina Messai ◽  
Vanesa Estepa ◽  
Carmen Torres ◽  
Rabah Bakour
Keyword(s):  
Resistance Genes ◽  
Klebsiella Oxytoca ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Phylogenetic Groups ◽  
Disk Diffusion Method ◽  
Hospital Effluents ◽  
Sequence Types

Introduction: Hospital effluents are a source of environmental pollution by drugs, antibiotic-resistant bacteria, and resistance genes. Quinolones, particularly ciprofloxacin, are commonly detected in these effluents, contributing to the emergence of antimicrobial resistance. The objective of this study was to characterize ciprofloxacin-resistant Enterobacteriaceae in hospital effluents. Methodology: Isolates were selected on Tergitol-7 agar supplemented with ciprofloxacin and genotyped by ERIC-PCR. Antibiotic susceptibility testing was done using the disk diffusion method, and minimum inhibitory concentrations were determined using the agar dilution method. Resistance genes, integrons, phylogenetic groups, and sequence types were identified by PCR and sequencing. Results: A total of 17 ciprofloxacin-resistant isolates were characterized: Escherichia coli, Escherichia vulneris, Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter freundii, and Citrobacter koseri/farmeri. Isolates presented concomitant resistance to nalidixic acid, ciprofloxacin, ofloxacin, and pefloxacin. A diversity in mutation patterns in gyrA and parC genes and new amino-acid substitutions in GyrA subunit were observed. Quinolone plasmidic resistance genes qnrB1, qnrB2, qnrB5/19, qnrS1, and aac(6’)-Ib-cr were detected. Resistance to other antibiotic classes was observed. Class 1 integrons and resistance genes blaCTX-M-15, blaOXA-1, sul1, sul2, sul3, tetA, tetB, aadA1/2, aadA5, aph(3’)-Ia, aac(3)II, dfrA1, dfrA5, dfrA7, and dfrA12 were detected. Bacterial tolerance to cadmium, zinc, and mercury was observed with the presence of the merA gene. E. coli isolates belonged to phylogenetic groups A, B1, and D and to sequence types ST405, ST443, ST101, ST10, and ST347. Conclusions: This study highlighted bacterial multidrug resistance linked to ciprofloxacin and, consequently, the risk of bacterial exposure to this antibiotic.

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