Multidrug Resistance Related to Biofilm Formation in Acinetobacter baumannii and Klebsiella pneumoniae Clinical Strains from Different Pulsotypes.

The emergence of Acinetobacter baumannii and Klebsiella pneumoniae strains in the hospital environment has been associated with the presence of multiple genetic elements, virulence factors and the ability to form biofilms. This study evaluated the biofilm formation ability of clinical and environmental A. baumannii and K. pneumoniae strains, isolated from various sources and presenting different molecular characteristics, resistance profiles and pulsed-field gel electrophoresis patterns. Fifty-three isolates were recovered from 2009 to 2014 in a Brazilian university hospital. Investigation of biofilm formation was performed for 10 strains of each species assessed by an initial adhesion assay, biofilm cell concentration and biofilm biomass, evaluated by quantitative assays in replicates, in three independent experiments. All strains of A. baumannii were able to attach to polystyrene plates, although two strains adhered to a lesser degree than the control. K. pneumoniae strains showed opposite behaviour, where only three strains adhered significantly when compared to the control. Quantitative evaluation revealed that in five A. baumannii and four K. pneumoniae isolates the biomass production could be characterised as moderate. None of the isolates were strong biofilm producers. Our results demonstrate: (1) biofilm formation is a heterogeneous property amongst A. baumannii and K. pneumoniae clinical strains and it was not associated with certain clonal types; (2) no relationship between multidrug resistance and biofilm production was observed; (3) more virulent K. pneumoniae strains tended to present higher production of biofilm.

Multicentre surveillance of epidemiologically important pathogens causing nosocomial bloodstream infections and pneumonia trials in Brazilian adult intensive care units.

Introduction. Healthcare-associated infections (HAIs) are the most recurrent adverse event in hospitals worldwide and represent an important public health problem.Gap statement. There are a paucity of multicentric data describing severe HAIs such as bloodstream infection (BSI) and pneumonia in Brazil.Aim. To provide an up-to-date picture of the extent and patterns of HAIs in adult intensive care units (ICUs), as well as to identify variables associated with the risk of development of severe infections.Methodology. Point prevalence surveys were conducted using standardized protocols in 35 ICUs from Minas Gerais state, Brazil. Medical records of eligible inpatients at or before 8 am on the survey day were reviewed to identify HAIs present at the time of the survey. A matched-pairs case-control study was performed on a total of 66 pairs for BSI and 115 pairs for pneumonia according to the selection criteria developed.Results. Overall, 171 patients (45.7%) had at least one HAI, with most (78.4%) acquired in the ICU. These patients presented a total of 240 infections; including 123 pneumonia (51.3%) and 66 BSI (27.5%), and 78.9 and 80.3 %, respectively, were acquired in the ICU. Their aetiology showed a predominance of Gram-negative bacteria versus Gram-positive bacteria (48.9 versus 43.3 %), with Acinetobacter baumannii (13.7%) and Pseudomonas aeruginosa (12.8%) being prominent. One striking observation from our data was the higher prevalence of Staphylococcus aureus (14.5%) and coagulase-negative staphylococci (10.2%) observed in the overall HAIs.Conclusion. A high severe ICU-acquired HAI burden was found when compared with findings from other low- and middle-income countries. These data can be utilized for better planning of nosocomial infection surveillance programmes in our hospitals.

An another perspective of face masks in emotion recognition: Comment on Shepherd and Rippon (2022).

In a recent article, Shepherd and Rippon (2022) investigated the impact of widespread face mask use on emotion recognition. They found that mask-wearing led to reduced accuracy in identifying emotions such as fear, sadness, and disgust when participants were exposed to brief facial stimuli. Their study highlights the significance of masks in concealing facial areas crucial for non-verbal communication, potentially affecting emotional well-being. Here in this comment, we have argued that despite concerns about impaired emotional recognition and social interactions, balancing COVID-19 protection and effective communication is essential. We stress the importance of adhering to mask guidelines while enhancing alternative cues and communication strategies. In public health emergencies like COVID-19, such research should acknowledge the whole complexity and prioritize safety aspects in a manner that prevents controversial issues.

Appraising epidemiology data and antimicrobial resistance of urinary tract infections in critically ill adult patients: a 7-year retrospective study in a referral Brazilian hospital.

BACKGROUND: Urinary tract infections (UTI) are highly preventable and have significant clinical and financial impact on the patient and the health care system. OBJECTIVE: To investigate UTIs in critically ill adult patients and the relationship of antimicrobial consumption and multidrug-resistant isolate. DESIGN AND SETTING: A cohort study performed in a Brazilian tertiary-care university hospital in the city of Uberlandia (MG), located at the Federal University of Uberlandia, southeast region of the country. METHODS: We analyzed a cohort of 363 patients with first episode of UTIs from the adult intensive care unit (ICU), from January 2012 to December 2018. The daily doses of antimicrobial administered were calculated. RESULTS: The incidence rate of UTI was 7.2/1000 patient days, with 3.5/1000 patient-days of bacteriuria, and 2.1/1000 patient-days of candiduria. Of 373 microorganisms identified, 69 (18.4%) were Gram-positive cocci, 190 (50.9%) Gram-negative bacilli, and 114 yeasts (30.7%). Escherichia coli and Candida spp. were the most common. Patients with candiduria had higher comorbidity score (Charlson Comorbidity Index ≥ 3), longer length of stay (P = 0.0066), higher mortality (P = < 0.0001) severe sepsis, septic shock, and were immunocompromised when compared with patients with bacteriuria. We observed correlation between antibiotics consumption and multidrug-resistant (MDR) microorganisms. CONCLUSION: The UTIs incidence was high and was mainly caused by Gram-negative bacteria that were resistant to common antibiotics. We observed increase in the consumption of broad-spectrum antibiotics in ICU correlating with MDR microorganisms. In general, ICU-acquired candiduria may be associated with critical illness and poor prognosis.

Lipid nanoparticles based on natural matrices with activity against multidrug resistant bacterial species.

Lately, the bacterial multidrug resistance has been a reason to public health concerning around world. The development of new pharmacology therapies against infections caused by multidrug-resistant bacteria is urgent. In this work, we developed 10 NLC formulations composed of essential oils (EO), vegetable butter and surfactant. The formulations were evaluated for long-term and thermal cycling stability studies in terms of (particle size, polydispersion index and Zeta potential). In vitro antimicrobial assays were performed using disk diffusion test and by the determination of the minimum inhibitory concentration (MIC) performed with fresh and a year-old NLC. The most promising system and its excipients were structurally characterized through experimental methodologies (FTIR-ATR, DSC and FE-SEM). Finally, this same formulation was studied through nanotoxicity assays on the chicken embryo model, analyzing different parameters, as viability and weight changes of embryos and annexes. All the developed formulations presented long-term physicochemical and thermal stability. The formulation based on cinnamon EO presented in vitro activity against strains of Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa isolated from humans and in vivo biocompatibility. Considering these promising results, such system is able to be further tested on in vivo efficacy assays.

Risk factors for vancomycin-resistant enterococci colonisation in critically ill patients.

Vancomycin-resistant enterococci (VRE) are important hospital pathogens and have become increasingly common in patients admitted to the intensive care unit (ICU). To determine the incidence and the risk factors associated with VRE colonisation among ICU patients, active surveillance cultures for VRE faecal carriages were carried out in patients admitted to the ICU of the University Hospital of Uberlândia, Minas Gerais, Brazil. Risk factors were assessed using a case-control study. Seventy-seven patients (23.1%) were found to be colonised with vanC VRE and only one patient (0.3%) was colonised with vanA VRE. Independent risk factors for VRE colonisation included nephropathy [odds ratio (OR) = 13.6, p < 0.001], prior antibiotic use (OR = 5.5, p < 0.03) and carbapenem use (OR = 17.3, p < 0.001). Our results showed a higher frequency (23.1%) of Enterococcus gallinarum and Enterococcus casseliflavus, species that are intrinsically resistant to low levels of vancomycin (vanC), without an associated infection, associated with prior antibiotic use, carbapenem use and nephropathy as comorbidity. This study is the first to demonstrate the risk factors associated with vanC VRE colonisation in ICU hospitalised patients. Although vanA and vanB enterococci are of great importance, the epidemiology of vanC VRE needs to be better understood. Even though the clinical relevance of vanC VRE is uncertain, these species are opportunistic pathogens and vanC VRE-colonised patients are a potential epidemiologic reservoir of resistance genes.

Pressure ulcers colonized by MRSA as a reservoir and risk for MRSA bacteremia in patients at a brazilian university hospital.

UNLABELLED: Pressure ulcers (PU) are a major reservoir of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals. The objectives of this study were to estimate the prevalence of MRSA colonization in PU of hospitalized patients with Stage II or higher PU, to identify risk factors for colonization of these wounds, and to ascertain whether MRSA colonization of PU increases the risk of MRSA bacteremia. METHODS: This study was conducted at the Clinical Hospital of Federal University of Uberlandia, MG, Brazil. A prospective cohort study of 145 patients with Stage II or higher PU, colonized or not with MRSA, was conducted over 21 months. Infected ulcers were defined for clinical signs and for positive evaluation of smears of the wound by the ratio of polymorphonuclears to epithelial cells of ≥ 2:1, after Giemsa staining. RESULTS: Sixty-three (43.5%) MRSA colonized PU patients were identified, but none of the risk factors analyzed were independently associated with MRSA colonization. Among the patients with positive blood cultures and MRSA colonized PU, the odds ratio for MRSA bacteremia (OR = 19.0, 95% CI = 2.4-151.1, P < 0.001) and mortality rate (OR = 21.9, 95% CI = 1.23-391.5, P = 0.002), were high. Independent risk factors for MRSA bacteremia were: ≥ 2 underlying disease (OR = 6.26, 95% CI = 1.01-39.1, P = 0.05) and prior MRSA infected PU (OR = 12.75, 95% CI=1.22-132.9, P = 0.03). CONCLUSION: The present study identifies MRSA colonized PU patients as a potential epidemiologic reservoir for this organism and a high-risk for MRSA bacteremia, which contributes to prolonged hospitalization and poor prognosis. .

Staphylococcus aureus and Enterococcus faecium isolated from pigeon droppings (Columba livia) in the external environment close to hospitals.

BACKGROUND: Domestic pigeons carry pathogens in their droppings, posing a potential public health problem. METHODS: The phenotypic and genotypic antimicrobial resistances of Staphylococcus aureus and Enterococcus faecium in the feces of urban pigeons near hospitals with intensive care units were measured. RESULTS: Twenty-nine samples showed Enterococcus growth, whereas one was positive for S. aureus. The S. aureus isolate was sensitive to the antibiotics tested via antibiogram, however resistance genes were identified. E. faecium isolates showed phenotypic resistance to gentamicin, erythromycin, and ciprofloxacin. CONCLUSIONS: Antimicrobial profiles harmful to health were demonstrated in bacterial pathogens isolated from the external environment of hospitals.

Genetic Alterations Associated with Polymyxin B Resistance in Nosocomial KPC-2-Producing Klebsiella pneumoniae from Brazil.

The rapid increased multidrug resistance in Klebsiella pneumoniae has led to a renewed interest in polymyxin antibiotics, such as colistin, as antibiotics of last resort, not least in low/middle income countries. We conducted a genomic survey of clinical polymyxin-resistant K. pneumoniae to investigate the genetic alterations in isolates harboring blaKPC-2. Whole-genome sequencing was performed using an Illumina NextSeq 500 paired-end reads. Mutations and insertion sequence detection were analyzed to seven isolates recovered from clinical specimens of patients hospitalized in Brazil, focusing on key genes associated with polymyxin resistance. Furthermore, the levels of mRNA expression of genes associated with resistance to polymyxin B and other antimicrobials were evaluated by quantitative real-time PCR. Eighty-five percent of the isolates were assigned to clonal complex 258, with a minimum inhibitory concentration range of 4 to >256 mg/L for polymyxin B. It was possible to observe the presence of one important insertion element, ISKpn13, in a strain recovered from the blood that have blaKPC-2. Deleterious mutations reported in PmrB (R256G), YciM (N212T), and AcrB (T598A) were common, and mobile colistin resistance (mcr) genes were absent in all the isolates. RT-qPCR analysis revealed an overexpression of the pmrC (1.160-fold), pmrD (2.258-fold), and kpnE (1.530-fold) genes in the polymyxin B-resistant isolates compared with the expression of the polymyxin B-susceptible K. pneumoniae isolate. Overall, these results demonstrate the diversity of genetic variations in polymyxin-resistant populations derived from the different clonal strains, but the same sequence types, and suggest that there are still unknown mechanisms of polymyxin resistance in K. pneumoniae.

Gram-negative bacilli bacteremia: a 7 year retrospective study in a referral Brazilian tertiary-care teaching hospital.

Introduction. Bloodstream infection is one of the most frequent and challenging hospital-acquired infections and it is associated with high morbidity, mortality and additional use of healthcare resources.Hypothesis/Gap Statement: Bloodstream infections have consequences for the patient, such as the evolution to mortality and inappropriate empirical antibiotic prescription, especially when caused by multidrug-resistant Gram-negative bacilli.Objective. To assess the impact of bloodstream infection and the status of multidrug resistance (MDR) in the evolution of patients who received inappropriate initial antibiotic therapy.Methods. A retrospective surveillance was conducted on nosocomial bloodstream infections caused by Gram-negative bacilli (GNB) from January 2012 to December 2018 in an adult intensive care unit of a Brazilian tertiary teaching hospital.Results. We identified 270 patients with GNB nosocomial bacteremia. Non-survivors were older (with an average age of 58.8 years vs 46.9 years, P=<0.0001), presented more severe illnesses, were immunosuppressed (73.7 vs 37.6%, P=<0.0001), were more likely to have septic shock (55.8 vs 22.4%, P=<0.0001) and had an increased usage of mechanical ventilators (98.6 vs 89.6%, P=0.0013) than survivors. In a logistic regression model, inappropriate empirical antibiotic therapy was not an independent predictor of mortality, different from mechanical ventilator (P=<0.0001; OR=28.0; 95% CI=6.3-123.6), septic shock (P=0.0051; OR=2.5; 95% CI=1.3-4.9) and immunosuppression (P=0.0066; OR=2.6; 95% CI=1.3-5.2). In contrast, in a separate model, MDR was strongly associated with the prescription of inappropriate initial antibiotic therapy (P=0.0030; OR=5.3; 95% CI=1.7-16.1). The main isolated pathogens were Acinetobacter baumannii (23.6 %) and Klebsiella pneumoniae (18.7 %). The frequency of MDR organisms was high (63.7 %), especially among non-fermenting bacilli (60.9 %), highlighting A. baumannii (81.6 %) and Pseudomonas aeruginosa (41.8 %).Conclusion. Illness severity (septic shock and immunosuppression) and mechanical ventilation were identified as predictors of mortality. Additionally, MDR was a major determinant of inappropriate antibiotic empirical therapy, but not associated with mortality, and both characteristics were not statistically associated with death.

High mortality by nosocomial infections caused by carbapenem-resistant P. aeruginosa in a referral hospital in Brazil: facing the perfect storm.

Introduction. Carbapenem-resistant Pseudomonas aeruginosa is responsible for increased patient mortality.Gap Statement. Five and 30 day in-hospital all-cause mortality in patients with P. aeruginosa infections were assessed, followed by evaluations concerning potential correlations between the type III secretion system (TTSS) genotype and the production of metallo-ß-lactamase (MBL).Methodology. This assessment comprised a retrospective cohort study including consecutive patients with carbapenem-resistant infections hospitalized in Brazil from January 2009 to June 2019. PCR analyses were performed to determine the presence of TTSS-encoding genes and MBL genes.Results. The 30-day and 5-day mortality rates for 262 patients were 36.6 and 17.9 %, respectively. The unadjusted survival probabilities for up to 5 days were 70.55 % for patients presenting exoU-positive isolates and 86 % for those presenting exo-negative isolates. The use of urinary catheters, as well as the presence of comorbidity conditions, secondary bacteremia related to the respiratory tract, were independently associated with death at 5 and 30 days. The exoS gene was detected in 64.8 % of the isolates, the presence of the exoT and exoY genes varied and exoU genes occurred in 19.3 % of the isolates. The exoU genotype was significantly more frequent among multiresistant strains. MBL genes were not detected in 92 % of the isolates.Conclusions. Inappropriate therapy is a crucial factor regarding the worse prognosis among patients with infections caused by multiresistant P. aeruginosa, especially those who died within 5 days of diagnosis, regardless of the genotype associated with TTSS virulence.

Infections and antimicrobial resistance in an adult intensive care unit in a Brazilian hospital and the influence of drug resistance on the thirty-day mortality among patients with bloodstream infections.

INTRODUCTION: The present study aimed to determine the incidence of health care-associated infections (HCAIs) and identify the main resistant microorganisms in intensive care unit (ICU) patients in a Brazilian university hospital. METHODS: A retrospective cohort study was conducted in a Brazilian teaching hospital between 2012 and 2014. RESULTS: Overall, 81.2% of the infections were acquired in the ICU. The most common resistant pathogenic phenotypes in all-site and bloodstream infections were oxacillin-resistant coagulase-negative staphylococci and carbapenem-resistant Acinetobacter spp. (89.9% and 87.4%; 80.6% and 70.0%), respectively. CONCLUSIONS: There is an urgent need to focus on HCAIs in ICUs in Brazil.

Novel small IncX3 plasmid carrying the blaKPC-2 gene in high-risk Klebsiella pneumoniae ST11/CG258.

This study used whole-genome sequencing (WGS) and PFGE to analysis KPC-2-producing Klebsiella pneumoniae strains from clinical specimens collected in Brazilian hospitals. The study identifies the emergence of a novel small IncX3 plasmid (pKPB11), 12,757-bp in length, in a high-risk K. pneumoniae ST11/CG258 lineage, a successful clonal group in Brazil, carrying the blaKPC-2 gene on a non-Tn4401 genetic element (NTEKPC-Ic). Comparative analysis of the pKPB11 showed that this plasmid reduced its size, losing part of its conjugation apparatus. The pKPB11 was also compared to another strain sequenced in this study (KPC89) that had the hybrid IncX3-IncU plasmid (pKP89), of approximately 45 kb in length, similarly carrying the blaKPC-2 gene on NTEKPC-Ic. To the best of our knowledge, pKPB11 is the first example of small IncX3 plasmid found in a high-risk KPC-2-producing K. pneumoniae ST11/CG258.

Incidence of infections caused by carbapenem-resistant Acinetobacter baumannii.

BACKGROUND: Carbapenem-resistant Acinetobacter baumannii (CR-Ab) has become a worrying health care problem, mainly in developing countries, such as Brazil. The objective was to investigate the prevalence and prognostic factors for CR-Ab infections at a Brazilian university hospital and examine the impact of inappropriate antimicrobial therapy on patient outcome. METHODS: A retrospective study on hospitalized patients with CR-Ab infections was carried out from January 2013 to December 2017. An epidemiologic analysis was carried out to determine the frequency of infections, the epidemiologic indicators by year, the risk factors for 30-day mortality, and the impact of inappropriate therapy. RESULTS: A total of 489 patients were included in the study. A rate of 0.7 per 1,000 patient-day CR-Ab infections was observed, mostly in the lungs (54.7%), and predominantly in the adult intensive care unit. The occurrence of infections by CR-Ab per 1,000 patient-days in November 2014 exceeded the established control limit, confirming an outbreak. CONCLUSIONS: The prevalence of CR-Ab increased in the investigated hospital, passing to an endemic pathogen with a direct impact on mortality and the control of these strains.

Molecular Detection of Class 1 Integron-Associated Gene Cassettes in KPC-2-Producing Klebsiella pneumoniae Clones by Whole-Genome Sequencing.

The dissemination of antimicrobial resistance genes and the bacterium that harbor them have increasingly become a public concern, especially in low- and middle-income countries. The present study used whole-genome sequencing to analyze 10 KPC-2-producing Klebsiella pneumoniae isolates obtained from clinical specimens originated from Brazilian hospitals. The study documents a relevant "snapshot" of the presence of class 1 integrons in 90% of the strains presenting different gene cassettes (dfrA30, dfrA15, dfrA12, dfrA14, aadA1, aadA2, and aac(6')Iq), associated or not with transposons. Two strains presented nonclassical integron (lacking the normal 3'conserved segment). In general, most strains showed a complex resistome, characterizing them as highly resistant. Integrons, a genetically stable and efficient system, confer to bacteria as highly adaptive and low cost evolution potential to bacteria, even more serious when associated with high-risk clones, indicating an urgent need for control and prevention strategies to avoid the spread of resistance determinants in Brazil. Despite this, although the class 1 integron identified in the KPC-2-producing K. pneumoniae clones is important, our findings suggest that other elements probably have a greater impact on the spread of antimicrobial resistance, since many of these important genes were not related to this cassette.

Appraising epidemiology data and antimicrobial resistance of urinary tract infections in critically ill adult patients: a 7-year retrospective study in a referral Brazilian hospital

ABSTRACT BACKGROUND: Urinary tract infections (UTI) are highly preventable and have significant clinical and financial impact on the patient and the health care system. OBJECTIVE: To investigate UTIs in critically ill adult patients and the relationship of antimicrobial consumption and multidrug-resistant isolate. DESIGN AND SETTING: A cohort study performed in a Brazilian tertiary-care university hospital in the city of Uberlandia (MG), located at the Federal University of Uberlandia, southeast region of the country. METHODS: We analyzed a cohort of 363 patients with first episode of UTIs from the adult intensive care unit (ICU), from January 2012 to December 2018. The daily doses of antimicrobial administered were calculated. RESULTS: The incidence rate of UTI was 7.2/1000 patient days, with 3.5/1000 patient-days of bacteriuria, and 2.1/1000 patient-days of candiduria. Of 373 microorganisms identified, 69 (18.4%) were Gram-positive cocci, 190 (50.9%) Gram-negative bacilli, and 114 yeasts (30.7%). Escherichia coli and Candida spp. were the most common. Patients with candiduria had higher comorbidity score (Charlson Comorbidity Index ≥ 3), longer length of stay (P = 0.0066), higher mortality (P = < 0.0001) severe sepsis, septic shock, and were immunocompromised when compared with patients with bacteriuria. We observed correlation between antibiotics consumption and multidrug-resistant (MDR) microorganisms. CONCLUSION: The UTIs incidence was high and was mainly caused by Gram-negative bacteria that were resistant to common antibiotics. We observed increase in the consumption of broad-spectrum antibiotics in ICU correlating with MDR microorganisms. In general, ICU-acquired candiduria may be associated with critical illness and poor prognosis.

Hypervirulence and biofilm production in KPC-2-producing Klebsiella pneumoniae CG258 isolated in Brazil.

In this study, we describe the frequency of virulence genes in Klebsiella pneumoniae carbapenemase-2-producing Klebsiella pneumoniae (KPC-KP), including hypervirulent (hv) and hypermucoviscous (hm) strains by whole-genome sequencing. We also evaluate the capacity for biofilm formation by using phenotypic techniques. The occurrence of several virulence genes (fimABCDEFGHIK, mrkABCDFHJ, ecpA, wabG, entB, ugE, irp1, irp2, traT, iutA and ureADE) and a high frequency of hvhmKPC-KP isolates was found. Most hospital-associated lineages of KPC-KP belong to the international clonal group 258 (CG258). Biofilm formation was a constant feature among 90.9 % of KPC-KP strains. This report suggests a close relationship between ST437 and weak biofilm production, given that all weakly biofilm-producing strains belonged to this sequence type. This also supports the dissemination of KPC-KP containing numerous virulence determinants belonging to the biofilm-producing CG258 type in Brazil, including hv and hm strains. These factors allow this pathogen to cause infections, leading to its rapid expansion and persistence in hospital settings.

Association of Colistin-Resistant KPC Clonal Strains with Subsequent Infections and Colonization and Biofilm Production.

Carbapenemase-producing organisms are pandemic and a significant threat to public health. We investigated the clonal relatedness of colistin-resistant Klebsiella pneumoniae strains producing KPC-type carbapenemase (KPC-KP) causing subsequent infections or colonization. Moreover, we aimed to gain insight into the ability of biofilm production in K. pneumoniae strains producing carbapenemase. Twenty-two consecutive KPC-KP and one KPC-negative strain was identified from an adult intensive care unit in Brazil. Seventy-five percent of isolates that harbored the blaKPC gene exhibited genetic relatedness by pulsed-field gel electrophoresis, and none presented the plasmid-mediated mcr-1 and blaNDM genes. This study showed that the majority of repeated KPC infections in adults were caused by a clone that caused the previous infections/colonizations even after a long period of time and illustrates the capacity of multiple clones producing biofilms to coexist in the same patient at the same time, becoming a reservoir of KPC-KP in the hospital environment.

Molecular characterization and clonal dynamics of nosocomial blaOXA-23 producing XDR Acinetobacter baumannii.

The emergence of infections associated to new antimicrobial resistance in Acinetobacter baumannii (Ab) genotypes represents a major challenge. In this context, this study aimed to determine the diversity of resistance mechanisms and investigate clonal dissemination and predominant sequence types (STs) in multidrug-resistant Ab strains of clinical (tracheal aspirate, n = 17) and environmental (surface, n = 6) origins. Additionally, the major clones found in clinical (A) and environmental (H) strains had their complete genomes sequenced. All strains were submitted to polymerase chain reactions (PCR) for the detection of the ISAba1/blaOXA-51-like and ISAba1/blaOXA-23-like genes, while the expression of genes encoding the carO porin, AdeABC (adeB), AdeFGH (adeG), and AdeIJK (adeJ) efflux pumps was determined by real time PCR (qPCR). Most of the strains were characterized as extensively drug-resistant (XDR) with high minimal inhibitory concentrations (MICs) detected for tigecycline and carbapenems. Associations between ISAba1/OXA-51 and ISAba1/OXA-23 were observed in 91.3% and 52.2% of the strains, respectively. Only the adeB gene was considered hyper-expressed. Furthermore, most of the strains analyzed by the MuLtilocus Sequence-Typing (MLST) were found to belong to the clonal complex 113 (CC113). In addition, a new ST, ST1399, belonging to CC229, was also discovered herein. Strains analyzed by whole genome sequencing presented resistance genes linked to multidrug-resistance phenotypes and confirmed the presence of Tn2008, which provides high levels carbapenem-resistance.

Vancomycin-resistant VanA phenotype Enterococcus faecalis: first case in Minas Gerais state and epidemiological considerations.

We report the first case of vancomycin-resistant Enterococcus faecalis with VanA phenotype and vanA genotype isolated from a surgical patient in a general Hospital in Uberlândia, state of Minas Gerais, Brazil.