Antimicrobial use, incidence, etiology and resistance patterns in bacteria causing ventilator-associated pneumonia in a clinical-surgical intensive care unit

Characterization of biofilm formation and multi-drug resistance among Pseudomonas aeruginosa isolated from hospital wastewater in Dhaka, Bangladesh

Hospital wastewater has been identified as a hotspot for the emergence and transmission of multidrug-resistant (MDR) pathogens that present a serious threat to public health. Therefore, we investigated the current status of antibiotic resistance as well as the phenotypic and genotypic basis of biofilm formation in Pseudomonas aeruginosa from hospital wastewater in Dhaka, Bangladesh. The disc diffusion method and the crystal violet assay were performed to characterize antimicrobial resistance and biofilm formation, respectively. Biofilm and integron-associated genes were amplified by the polymerase chain reaction. Isolates exhibited varying degrees of resistance to different antibiotics, in which >80% of isolates showed sensitivity to meropenem, amikacin, and gentamicin. The results indicated that 93.82% of isolates were MDR and 71 out of 76 MDR isolates showed biofilm formation activities. We observed the high prevalence of biofilm-related genes, in which algD+pelF+pslD+ (82.7%) was found to be the prevalent biofilm genotypic pattern. Sixteen isolates (19.75%) possessed class 1 integron (int1) genes. However, statistical analysis revealed no significant association between biofilm formation and multidrug resistance (χ2 = 0.35, P = 0.55). Taken together, hospital wastewater in Dhaka city may act as a reservoir for MDR and biofilm-forming P. aeruginosa, and therefore, the adequate treatment of wastewater is recommended to reduce the occurrence of outbreaks.

Impacts of Pharmacy Intervention on Appropriateness of Antibiotics Use in Pneumonia Patients

AIM: This study analyzed the impact of pharmacy intervention on appropriateness of antibiotics use in the treatment of inpatients with pneumonia admitted to Universitas Sumatera Utara (USU) Hospital, Medan, Indonesia. METHODS: This cohort study analyzed appropriateness of antibiotic use in the treatment of in-patients with pneumonia without interventions or baseline group (n = 33) admitted to USU Hospital year 2018 and 3-month period admission with pharmacy intervention (n = 42) year 2019. Characteristics of the patients and antibiotics provided to both groups were descriptively analyzed. The appropriateness of antibiotics use in both groups was analyzed based on their medical conditions, culture and sensitivity tests, and trustable literatures, and then categorized applying Gyssens method regarding dose, intervals, routes, length of provision, effectivity, and costs. The significant difference in inappropriate use of antibiotics between groups with and without interventions was analyzed applying unpaired t-test (p < 0.05 was considered statistically significant). RESULTS: Most of the pneumonia patients in both groups were male. Mean age of the patients (years) in group: without intervention, 60.20 ± 15.48; with intervention, 60.48 ± 14.76. The three most widely provided antibiotics were ceftriaxone, meropenem, and ciprofloxacin. Incidence of inappropriate use of antibiotics per patient in group: without intervention, 0.66; with intervention, 0.33. The inappropriate use of antibiotics reduced significantly in group with intervention, p = 0.049. CONCLUSIONS: Pharmacy intervention is crucial to reduce the inappropriate use of antibiotics in the treatment of pneumonia.

Antibiotic use in Brazilian hospitals in the 21st century: a systematic review

INTRODUCTION

This systematic review aimed to assess antibiotic use in Brazilian hospitals in the 21st century, as well as to understand the different drug utilization metrics adopted to assess the consumption of these drugs.

METHODS

We systematically reviewed five databases (MEDLINE [Medical Literature Analysis and Retrieval System Online], CENTRAL [The Cochrane Central Register of Controlled Trials], EMBASE® [Excerpta Medica Database], Scopus [Elsevier's abstract and citation database], and LILACS [Literatura Latino-Americana e do Caribe em Ciências da Saúde]) for observational or experimental studies that assessed antibiotic utilization in Brazilian hospitals. The main outcomes were the drug utilization metrics and the consumption of antibiotics.

RESULTS

We included 23 studies, of which 43.5% were carried out in adult and pediatric care units, 39.1% in adult units, and 17.4% in pediatric units. Regarding the complexity of healthcare, 26.1% of the studies were performed in intensive care units. Two drug utilization metrics were used in these studies: the defined daily dose (DDD) and the percentage of antibiotic prescriptions. The most commonly used antibiotic classes were third-generation cephalosporins, carbapenems, fluoroquinolones, and combinations of penicillins when the DDD was the adopted drug utilization metric.

CONCLUSIONS

Although few studies have been conducted, existing data indicate a high use of broad-spectrum antibiotics. We found that the lack of standardized antibiotic utilization metrics impaired the mapping of drug consumption at the national level.

Survival rate in patients with ICU-acquired infections and its related factors in Iran's hospitals

BACKGROUND

Hospital-acquired infections (HAIs) are a well-known cause of morbidity and mortality in hospitalized patients. This study aimed at investigating the survival rate in patients with ICU-acquired infections (ICU-AIs) and its related factors in Iran's hospitals.

METHODS

Data were obtained from the Iranian Nosocomial Infections Surveillance (INIS), which registers all necessary information on the main types of infection from different units of each included hospital. One thousand one hundred thirty-four duplicate cases were removed from the analysis using the variables of name, father's name, age, hospital code, infection code, and bedridden date. From 2016 to 2019, 32,998 patients diagnosed with ICU-AI from about 547 hospitals. All patients were followed up to February 29, 2020.

RESULTS

The median age of patients with ICU-AIs was 61 (IQR = 46) years. 45.5, 20.69, 17.63, 12.08, and 4.09% of infections were observed in general, surgical, internal, neonatal and pediatric ICUs, respectively. Acinetobacter (16.52%), E.coli (12.01%), and Klebsiella (9.93%) were the major types of microorganisms. From total, 40.76% of infected patients (13,449 patients) died. The 1, 3, 6-months and overall survival rate was 70, 25.72, 8.21 1.48% in ICU-AI patients, respectively. The overall survival rate was 5.12, 1.34, 0.0, 51.65, and 31.08% for surgical, general, internal, neonatal and pediatric ICU, respectively. Hazard ratio shows a significant relationship between age, hospitalization-infection length, infection type, and microorganism and risk of death in patients with ICU-AI.

CONCLUSIONS

Based on the results, it seems that the nosocomial infections surveillance system should be more intelligent. This intelligence should act differently based on related factors such as the age of patients, hospitalization-infection length, infection type, microorganism and type of ward. In other words, this system should be able to dynamically provide the necessary and timely warnings based on the factors affecting the survival rate of infection due to the identification, intervention and measures to prevent the spread of HAIs based on a risk severity system.

Microbiology of Ventilator-associated Pneumonia in a Tertiary Care Cancer Hospital

Background

Ventilator-associated pneumonia (VAP) is an important cause of healthcare-associated infections, resulting in prolonged hospitalization with increased morbidity and mortality. Knowledge of predominant local pathogens and their antimicrobial susceptibility patterns helps in selection of appropriate initial antibiotic therapy in these critical cases.

Aim and objective

The aim and objective of this study is to characterize the microbiology and antimicrobial susceptibility patterns of VAP isolates in a tertiary cancer center.

Materials and methods

This is a 4-year qualitative observational study carried out at a tertiary care cancer hospital in Mumbai. All nondirect bronchoalveolar lavage specimens from patients with a clinical suspicion of VAP sent from the critical care unit to the department of microbiology were processed as per standard laboratory procedures. All isolates were identified to species level and an antimicrobial susceptibility testing was performed by the Kirby–Bauer disk diffusion method and/or the VITEK 2 automated identification and susceptibility system, according to Clinical and Laboratory Standards Institute guidelines.

Results

The study comprised 1,074 patients: 710 (66.10%) men and 364 (33.90%) women. A total of 827 bacterial isolates were obtained with 780 (94.32%) gram-negative organisms and 47 (5.68%) gram-positive organisms; of which Acinetobacter baumannii (38.7%), Pseudomonas aeruginosa (17.5%), and Klebsiella pneumoniae (16.6%) were the commonest. Of gram-negative bacilli, multidrug-resistant organisms constituted 87.50% and were susceptible to colistin.

Conclusions

VAP is associated with pathogens, such as A. baumannii, P. aeruginosa, and K. pneumoniae in our setting. High rates of resistance to aminoglycosides, β-lactam-β-lactamase inhibitor combinations, and carbapenems were noted.

How to cite this article

Sangale A, Bhat V, Kelkar R, Biswas S. Microbiology of Ventilator-associated Pneumonia in a Tertiary Care Cancer Hospital. Indian J Crit Care Med 2021;25(4):421–428.

The epidemiology of carbapenem-non-susceptible Acinetobacter species in Europe: analysis of EARS-Net data from 2013 to 2017

BACKGROUND

Due to limited therapeutic options and their association with high mortality and morbidity, carbapenem-non-susceptible Acinetobacter spp. (CNA) are of significant public health importance. This study aimed to describe current epidemiological trends of CNA proportions in Europe and to identify factors that are associated with carbapenem non-susceptibility of isolates from patients with invasive Acinetobacter spp. infections.

METHODS

Data from routine carbapenem susceptibility testing of 18,412 invasive clinical Acinetobacter spp. isolates from 30 European countries in 2013-2017 were analysed using descriptive statistical analyses and uni- and multivariable regression analyses. These data were obtained from the European Antimicrobial Resistance Surveillance Network (EARS-Net).

RESULTS

The population-weighted mean proportion of carbapenem-non-susceptible Acinetobacter spp. in Europe is 35.6% (95% confidence interval [CI] 29.7-42.0%). With CNA proportions of 75.5% (95% CI 71.2-79.4%) and 71.5% (95% CI 66.7-75.9%) the burden of CNA is particularly high in Southern and Eastern European regions. In contrast, Northern and Western European regions recorded CNA proportions of 2.8% (95% CI 1.2-6.0%) and 6.3% (95% CI 4.5-8.9%), respectively. Population-weighted mean CNA proportions are especially high in Acinetobacter spp. isolates from intensive care units (54.0% [95% CI 47.6-60.3%]). Male gender, age above 20 years and ICU admission were identified as independent factors associated with an increased likelihood of CNA.

CONCLUSION

The burden of carbapenem-non-susceptible Acinetobacter spp. is particularly high in Southern and Eastern Europe. There is a risk that resistance could spread to other parts of Europe. Therefore, increased efforts in infection control and antibiotic stewardship, particularly in Intensive Care Units, are necessary to combat the spread of CNA in Europe.

Evaluation of antimicrobial resistance, biofilm forming potential, and the presence of biofilm-related genes among clinical isolates of Pseudomonas aeruginosa

OBJECTIVES

Pseudomonas aeruginosa is known as a leading cause of nosocomial infections worldwide. Antimicrobial resistance and biofilm production, as two main virulence factors of P. aeruginosa, are responsible for the persistence of prolonged infections. In this study, antimicrobial susceptibility pattern and phenotypic and genotypic characteristics of biofilm of P. aeruginosa were investigated.

RESULTS

A total of 80 clinical P. aeruginosa isolates were obtained. Isolates showed resistance to all antibiotics with a rate from 12.5% (n = 10) against amikacin and piperacillin/tazobactam to 23.75% (n = 19) to levofloxacin. Multidrug-resistant P. aeruginosa accounted for 20% (n = 16). 83.75% (n = 67) of isolates showed biofilm phenotype. All three biofilm-related genes were found simultaneously in 87.5% (n = 70) of P. aeruginosa and 13.5% (n = 10) of the isolates had none of the genes tested. From the results of the present study, combination therapy including an anti-pseudomonal beta-lactam (piperacillin/tazobactam or ceftazidime) and an aminoglycoside or carbapenems (imipenem, meropenem) with fluoroquinolones in conjunction with an aminoglycoside can be used against Pseudomonas infections. However, reasonable antimicrobial use and high standards of infection prevention and control are essential to prevent further development of antimicrobial resistance. Combination strategies based on the proper anti-pseudomonal antibiotics along with anti-biofilm agents can also be selected to eradicate biofilm-associated infections.

Antimicrobial resistance trends in methicillin-resistant and methicillin-susceptible Staphylococcus aureus and Staphylococcus epidermidisisolates obtained from patients admitted to intensive care units. 2010-2015

Introducción. La aparición y la diseminación de cepas resistentes en hospitales, principalmente en unidades de cuidado intensivo (UCI), se han convertido en un serio problema de salud pública.Objetivo. Analizar la tendencia de los fenotipos de resistencia de Staphylococcus aureus y Staphylococcus epidermidis resistentes y susceptibles a meticilina aislados en pacientes atendidos en UCI de un hospital de alta complejidad de Cartagena, Colombia, del 2010 al 2015.Materiales y métodos. Estudio analítico transversal realizado entre enero de 2010 y diciembre de 2015. Se utilizaron aislamientos de S. aureus y S. epidermidis meticilino-susceptibles y meticilino-resistentes (SARM, SASR, SERM y SESM). La técnica de susceptibilidad empleada fue el método microdilución en caldo para la detección de la concentración mínima inhibitoria.Resultados. Se identificaron 313 aislamientos de Staphylococcus spp., la mayoría resistentes a meticilina (63.6%). Las cepas SARM y SERM correspondieron al 13.7% y al 27.8% del total de aislamientos, respectivamente. Los mayores porcentajes de resistencia en SARM y SERM correspondieron a eritromicina (57.6% y 81.2%, respectivamente), clindamicina (54.6% y 71.0%), ciprofloxacina (48.4% y 36.4%) y trimetoprima-sulfametoxazol (36.4% y 51.4%).Conclusión. Los resultados encontrados sugieren el replanteamiento de las estrategias de control de la resistencia antimicrobiana en el hospital objeto de estudio.

The Top-100 Highly Cited Original Articles on Drug Therapy for Ventilator-Associated Pneumonia

Background: In recent decades, research on drug therapy for ventilator-associated pneumonia (VAP) remains one of the major hot-spots in the field of critical care medicine, but relevant data are not satisfactory. Our aim was to assess the status and trends of the most cited articles on drug therapy for VAP through bibliometric approaches. Methods: The Institute for Scientific Information (ISI) Web of Science core collection database was searched for the VAP-related articles. The time period for retrieval was from the beginning of the database to September 30, 2018. The top 100 most cited articles were selected to obtain their information on the authors, title, publication, number of citations, author's affiliations, country, etc. These general information and bibliometric data were collected for analysis. VOSviewer software was used to generate a term co-occurrence graph that visualized a reference pattern for different terms in the 100 articles. Results: The number of citations for the 100 selected articles ranged from 142 to 3,218. These articles were published in 31 different journals. The top three journals in terms of the number of our selected articles they published were "Critical Care Medicine" (17 articles), "American Journal of Respiratory and Critical Care Medicine" (11 articles) and "Clinical Infectious Diseases" (10 articles). The most frequently nominated author was Marin H. Kollef from the University of Washington, and of the top 100 articles, 16 listed his name. These top 100 articles were published after the year of 2000. The most common type of article in the top 100 was an original article (53%). The United States and France were the countries that contributed the most articles to the top 100. Gram-negative bacilli, pseudomonas aeruginosa, antibiotics, risk factors and other terms appeared more frequently, suggesting that attentions on this issue currently focused on the rational application and management of antibiotics. Conclusion: This study analyzed the 100 most cited articles on drug-treated VAP, and provided insights into the historical developments and characteristics of the most cited articles in the field of VAP.

High antimicrobial resistant rates among Gram-negative pathogens in intensive care units. A retrospective study at a tertiary care hospital in Southwest Saudi Arabia

OBJECTIVES

To determine the distribution and resistance profiles of Gram-negative bacteria (GNB) in intensive care units (ICUs) at King Abdullah Hospital in Bisha, Saudi Arabia. Methods: A record based retrospective study was conducted from December 2016 to January 2018. In total, 3736 non-duplicate clinical specimens from the general intensive care unit (ICU), neonatal ICU (NICU), and coronary CU (CCU) were analyzed for pathogens. Results: Of 3736 specimens, 9.6% (358) were positive for pathogens, and GNB constituted the majority (290/358; 81%). Acinetobacter is predominant in the general ICU, whereas Klebsiella pneumoniae is common in the NICU and CCU. Overall, GNB revealed a high resistance rate for cefuroxime (75.8%) trimethoprim/sulfamethoxazole (73.4%), cefotaxime (72.9%), aztreonam (64.6%), piperacillin (62.1%), and ciprofloxacin (61.5%). Acinetobacter revealed a high resistance (93.4% to 97.5%) to all antimicrobials except colistin (4%). Klebsiella pneumoniae showed a high resistance to trimethoprim/sulfamethoxazole (71.8%), cefotaxime (71.4%) and aztreonam (65.2%). Pseudomonas aeruginosa showed good activity for aminoglycosides but increasing resistance for cephalosporins and meropenem. GNB exhibited a high rate of multi-drug-resistant (MDR) phenotypes (67.9%) with a higher level among Acinetobacter spp. (97.5%). There were no significant differences in the resistance rates of GNB from different ICUs except for imipenem (p=0.002) and ciprofloxacin (p=0.003).  Conclusions: Increased antimicrobial resistance with high proportions of MDR patterns were found among GNB from ICUs. Comprehensive surveillance programs are needed to track the origins and emergence pathways of resistant pathogens.

Molecular epidemiological survey of bacteremia by multidrug resistant Pseudomonas aeruginosa: the relevance of intrinsic resistance mechanisms

The bacterial factors associated with bacteremia by multidrug-resistant and extensively drug-resistant P. aeruginosa, including overexpression of efflux pumps, AmpC overproduction, and loss/alteration of the OprD porin in isolates that are non-Metallo-β-Lactamase producing were analyzed in a retrospective study. Molecular analyses included strain typing by Pulsed Field Gel Electrophoresis and identification of key genes via qualitative and quantitative PCR-based assays. Previous use of carbapenems and tracheostomy was independently associated with the development of bacteremia by extensively drug-resistant and multidrug-resistant strains of P. aeruginosa. A high consumption of antimicrobials was observed, and 75.0% of the isolates contained amplicons with the blaSPM-1 and blaVIM genes. Of the 47 non-Metallo-β-Lactamase isolates, none had another type of carbapenemase. However, the isolates exhibited high rates of hyperproduction of AmpC, loss of the OprD porin (71.4%) and the presence of MexABOprM (57.1%) and MexXY (64.3%). This study suggests that in non-Metallo-β-Lactamase isolates, the association of intrinsic resistance mechanisms could contributes to the expression of multidrug-resistant/extensively drug-resistant phenotypes.

Drug-resistance dynamics of Staphylococcus aureus between 2008 and 2014 at a tertiary teaching hospital, Jiangxi Province, China

Background

To understand the relationship between the Staphylococcus aureus infection rate and the reasonable usage of antibiotics, which will help in the effective control of MRSA infection.

Methods

All data were obtained by the application of the nosocomial infection surveillance network. Drug resistance, departmental sources, and isolated sites as well as infection rate variations of S. aureus were analyzed in the 7-year period in key departments.

Results

Between 2008 and 2014, 2525 strains of S. aureus isolates, mainly from sputum, skin/soft tissue, bloodstreams were collected from several hospital departments including respiratory, burn, brain surgery, orthopedics, ICU, and emergency. During these periods, the resistance rate of S. aureus to most drugs, including oxacillin, tetracycline, erythromycin, clindamycin, gentamicin, and ciprofloxacin, showed a tendency to decrease. The resistance to sulphamethoxazole/trimethoprim showed the opposite trend (P = 0.075) and there were no S. aureus strains resistant to linezolid and vancomycin. The MRSA infection rate was different across crucial hospital departments, with the burns department and ICU maintaining a high infection level. Over the 7-year period, both the brain surgery and the emergency departments had an expected upward trend (P < 0.05), while the orthopedic department showed a clear downward trend (P < 0.05) in MRSA infection rate.

Conclusion

Hospitals should continue to maintain the current pattern of antibiotic administration, while more effective measures should be taken to reduce the high MRSA infection rate in some important hospital departments.

Carbapenem-resistant Pseudomonas aeruginosa: association with virulence genes and biofilm formation

Pseudomonas aeruginosa is an opportunistic pathogen that causes frequently nosocomial infections, currently becoming more difficult to treat due to the various resistance mechanisms and different virulence factors. The purpose of this study was to determine the risk factors independently associated with the development of bacteremia by carbapenem-resistant P. aeruginosa, the frequency of virulence genes in metallo-β-lactamases producers and to evaluate their ability to produce biofilm. We conducted a case–control study in the Uberlândia Federal University – Hospital Clinic, Brazil. Polymerase Chain Reaction was performed for metallo-β-lactamases and virulence genes. Adhesion and biofilm assays were done by quantitative tests. Among the 157 strains analyzed, 73.9% were multidrug-resistant, 43.9% were resistant to carbapenems, 16.1% were phenotypically positive for metallo-β-lactamases, and of these, 10.7% were positive for bla_SPM gene and 5.3% positive for bla_VIM. The multivariable analysis showed that mechanical ventilation, enteral/nasogastric tubes, primary bacteremia with unknown focus, and inappropriate therapy were independent risk factors associated with bacteremia. All tested strains were characterized as strongly biofilm producers. A higher mortality was found among patients with bacteremia by carbapenem-resistant P. aeruginosa strains, associated independently with extrinsic risk factors, however it was not evident the association with the presence of virulence and metallo-β-lactamases genes.

Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.These guidelines are intended for use by healthcare professionals who care for patients at risk for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), including specialists in infectious diseases, pulmonary diseases, critical care, and surgeons, anesthesiologists, hospitalists, and any clinicians and healthcare providers caring for hospitalized patients with nosocomial pneumonia. The panel's recommendations for the diagnosis and treatment of HAP and VAP are based upon evidence derived from topic-specific systematic literature reviews.

Clinical and Molecular Epidemiology of Multidrug-Resistant P. aeruginosa Carrying aac(6')-Ib-cr, qnrS1 and blaSPM Genes in Brazil

We described a comprehensive analysis of the molecular epidemiology of multidrug-resistant (MDR) P. aeruginosa. Molecular analysis included typing by Pulsed Field Gel Electrophoresis, identification of genes of interest through PCR-based assays and sequencing of target genes. Case-control study was conducted to better understand the prognostic of patients and the impact of inappropriate therapy in patients with bacteremia, as well as the risk factors of MDR infections. We observed a high rate of MDR isolates (40.7%), and 51.0% of them was independently associated with inappropriate antibiotic therapy. Bacteremia was detected in 66.9% of patients, and prolonged hospital stay was expressive in those resistant to fluoroquinolone. Plasmid-mediated quinolone resistance genes (PMQR), qnrS1 and aac(6')Ib-cr, were detected in two different nosocomial isolates (5.3%), and the aac(6')-Ib7 variant was detected at a high frequency (87.5%) in those negative to PMQR. The presence of mutations in gyrA and parC genes was observed in 100% and 85% of selected isolates, respectively. Isolates harboring PMQR genes or mutations in gyrA and parC were not closely related, except in those containing SPM (São Paulo metallo-β-lactamase) clone. In addition, there is no study published in Brazil to date reporting the presence of Pseudomonas aeruginosa isolates harboring both qnrS1 and aac(6')Ib-cr genes, with alarming frequency of patients with inappropriate therapy.

Molecular epidemiological survey of the quinolone- and carbapenem-resistant genotype and its association with the type III secretion system in Pseudomonas aeruginosa

This study evaluated the predictors of mortality and the impact of inappropriate therapy on the outcomes of patients with bacteraemia and ventilator-associated pneumonia (VAP). Additionally, we evaluated the correlation of the type III secretion system (TTSS) effector genotype with resistance to carbapenems and fluoroquinolones, mutations in the quinolone resistance-determining regions (QRDRs), metallo-β-lactamase and virulence factors. A retrospective cohort was conducted at a tertiary hospital in patients with multidrug-resistant (MDR) P. aeruginosa bacteraemia (157 patients) and VAP (60 patients). The genes for blaIMP, blaVIM, blaSIM, blaGIM and blaSPM and virulence genes (exoT, exoS, exoY, exoU, lasB, algD and toxA) were detected; sequencing was conducted for QRDR genes on fluoroquinolone-resistant strains. The multivariate analyses showed that the predictors independently associated with death in patients with bacteraemia were cancer and inappropriate therapy. Carbapenem resistance was more frequent among strains causing VAP (53.3 %), and in blood we observed the blaSPM genotype (66.6 %) and blaVIM genotype (33.3 %). The exoS gene was found in all isolates, whilst the frequency was low for exoU (9.4 %). Substitution of threonine to isoleucine at position 83 in gyrA was the most frequent mutation among fluoroquinolone-resistant strains. Our study showed a mutation at position 91 in the parC gene (Glu91Lys) associated with a mutation in gyrA (Thre83Ile) in a strain of extensively drug-resistant P. aeruginosa, with the exoT(+)exoS(+)exoU(+) genotype, that has not yet been described in Brazil to the best of our knowledge. This comprehensive analysis of resistance mechanisms to carbapenem and fluoroquinolones and their association with TTSS virulence genes, covering MDR P. aeruginosa in Brazil, is the largest reported to date.