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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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Studies show that Healthcare-associated infections (HAIs) represent a crucial issue in healthcare and can lead to substantial economic impacts in intensive care units (ICUs).Aim: To estimate direct costs associated with the most significant HAIs in 50 teaching hospitals in Brazil, affiliated to the Unified Health System (SUS).Methods: A Monte Carlo simulation model was designed to estimate the direct costs of HAIs; first, we established epidemiologic and economic parameters for each HAI based on a cohort of 949 critical patients (800 without HAI and 139 with); second, we used simulation based on three Brazilian prevalence scenarios of HAIs in ICU patients (29.1%, 51.2% and 61.6%) and third, we simulated the annual direct costs of HAIs in 50 university hospitals.Findings: Patients with HAIs had 16 additional days in the ICU, along with an extra direct cost of US $ 13.892, compared to those without HAIs. In one hypothetical scenario without HAI, the direct annual cost of hospital care for 26,649 inpatients in adult ICUs of 50 hospitals is US$ 112,924,421. There was an increase of approximately US$ 56M in a scenario with 29.1%, and an increase of US$147M in a scenario with 61.6%. The impact on the direct cost became significant starting at a 10% prevalence of HAIs, where US $ 2,824,817 is added for each 1% increase in prevalence.Conclusion: This analysis provides robust and updated estimates that HAI places a significant financial burden on the Brazilian healthcare system and contributes to a longer stay for inpatients. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction. Efforts to understand the burden of antibiotic use in low- and middle-income countries such as Brazil are essential for developing strategies that are effective and appropriate in the context of endemic multidrug-resistant organisms. Aim. This study aims to determine antimicrobial-prescribing practices among patients hospitalized in intensive care units (ICUs) for adults in Brazil. Methodology. A 1-day point prevalence multicentre survey was conducted in 58 adult ICUs across the five regions of Brazil. The institutions were categorized according to their type and size. Detailed antimicrobial prescription data were prospectively provided to all patients hospitalized on the day of data collection. Results. A total of 620 patients were included in the study, of whom 63.9% were receiving at least one antimicrobial. Of these, 34.6% were treated for an infection, but only 39.9% of the cases were based on microbiological criteria. Empirical treatment was applied to 72.3% of the patients. Significant differences in antibiotic usage were observed across the different hospitals included in the study. Overall, treatment was most commonly directed towards pneumonia (51.8%) and bloodstream infections (29.6%). Glycopeptides (19.4%) and carbapenems (18.5%) were the most prescribed in teaching hospitals, while in non-teaching hospitals, carbapenems (17.8%) and broad-spectrum cephalosporins (16.8%) were most frequently used. Conclusion. Our study reveals alarming data on antibiotic use in adult ICUs in Brazil, with high frequencies of severe healthcare-associated infections acquired in these units, where patients are frequently subjected to empirical treatment.

P21 is a protein secreted by all forms of Trypanosoma cruzi ( T. cruzi ) with recognized biological activities determined in studies using the recombinant form of the protein. In our recent study, we found that the ablation of P21 gene decreased Y strain axenic epimastigotes multiplication and increased intracellular replication of amastigotes in HeLa cells infected with metacyclic trypomastigotes. In the present study, we investigated the effect of P21 in vitro using C2C12 cell lines infected with tissue culture-derived trypomastigotes (TCT) of wild-type and P21 knockout (TcP21 -/- ) Y strain, and in vivo using an experimental model of T. cruzi infection in BALB/c mice. Our in-vitro results showed a significant decrease in the host cell invasion rate by TcP21 -/- parasites as measured by Giemsa staining and cell count in bright light microscope. Quantitative polymerase chain reaction (qPCR) analysis showed that TcP21 -/- parasites multiplied intracellularly to a higher extent than the scrambled parasites at 72h post-infection. In addition, we observed a higher egress of TcP21 -/- trypomastigotes from C2C12 cells at 144h and 168h post-infection. Mice infected with Y strain TcP21 -/- trypomastigotes displayed higher systemic parasitemia, heart tissue parasite burden, and several histopathological alterations in heart tissues compared to control animals infected with scrambled parasites. Therewith, we propose that P21 is important in the host-pathogen interaction during invasion, cell multiplication, and egress, and may be part of the mechanism that controls parasitism and promotes chronic infection without patent systemic parasitemia., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Silveira, Uombe, Velikkakam, Borges, Teixeira, de Almeida, Torres, Pereira, de Souza, Teixeira, Servato, Silva, Mineo, Ribas, Mortara, da Silveira and da Silva.)

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.

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.

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.

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.

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-β-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.

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.

Competing Interests: There are no conflicts of interest.

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., Competing Interests: The authors have declared that no competing interests exist.

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.

Plasmid-mediated quinolone resistance (PMQR) determinants combined with mutations in quinolone resistance-determining regions (QRDRs) and clonal dissemination were investigated in 40 fluoroquinolone-resistant Klebsiella pneumoniae and Escherichia coli isolates from nosocomial and community-acquired infections. We observed nucleotide substitutions in gyrA (Ser83Ile, Val37Leu, Lys154Arg, Ser171Ala, Ser19Asn, Ile198Val, Ser83Tyr, Ser83Leu, Asp87Asn and Asp87Gly) and parC genes (Ser80Ile, Glu84Lys, Ala129Ser, Val141Ala and Glu84Gly). Two novel substitutions were detected in the gyrA gene (Val37Leu and Ile198Val). The presence of PMQR genes predominated in community isolates (55.5 %). In addition to the frequent presence of the class 1 integron in isolates from community-acquired infections, the genetic similarity results obtained by PFGE showed high genomic diversity. This study suggests that management of multidrug-resistant Enterobacteriaceae isolates from the community are a possible source of genetic mobile elements that carry genes that confer resistance to fluoroquinolones. More attention should be paid to the surveillance of community-acquired infections.

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., (Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.)

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.