Olive oil nanoemulsion containing curcumin: antimicrobial agent against multidrug-resistant bacteria.

The present work aimed to develop, characterize, and evaluate the antibacterial and antibiofilm activity of two nanoemulsions (NEs) containing 500 µg/mL of curcumin from Curcuma longa (CUR). These NEs, produced with heating, contain olive oil (5%) and the surfactants tween 80 (5%) and span 80 (2.5%), water q.s. 100 mL, and were stable for 120 days. NE-2-CUR presented Ø of 165.40 ± 2.56 nm, PDI of 0.254, ζ of - 33.20 ± 1.35 mV, pH of 6.49, and Entrapment Drug Efficiency (EE) of 99%. The NE-4-CUR showed a Ø of 105.70 ± 4.13 nm, PDI of 0.459, ζ of - 32.10 ± 1.45 mV, pH of 6.40 and EE of 99.29%. Structural characterization was performed using DRX and FTIR, thermal characterization using DSC and TG, and morphological characterization using SEM, suggesting that there is no significant change in the CUR present in the NEs and that they remain stable. The MIC was performed by the broth microdilution method for nine gram-positive and gram-negative bacteria, as well as Klebsiella pneumoniae clinical isolates resistant to antibiotics and biofilm and efflux pump producers. The NEs mostly showed a bacteriostatic profile. The MIC varied between 125 and 250 µg/mL. The most sensitive bacteria were Staphylococcus aureus and Enterococcus faecalis, for which NE-2-CUR showed a MIC of 125 µg/mL. The NEs and ceftazidime (CAZ) interaction was also evaluated against the K. pneumoniae resistant clinical isolates using the Checkerboard method. NE-2-CUR and NE-4-CUR showed a synergistic or additive profile; there was a reduction in CAZ MICs between 256 times (K26-A2) and 2 times (K29-A2). Furthermore, the NEs inhibited these isolates biofilms formation. The NEs showed a MBIC ranging from 15.625 to 250 µg/mL. Thus, the NEs showed physicochemical characteristics suitable for future clinical trials, enhancing the CAZ antibacterial and antibiofilm activity, thus becoming a promising strategy for the treatment of bacterial infections caused by multidrug-resistant K. pneumoniae. KEY POINTS: • The NEs showed physicochemical characteristics suitable for future clinical trials. • The NEs showed a synergistic/additive profile, when associated with ceftazidime. • The NEs inhibited biofilm formation of clinical isolates.

In vitro evaluation of mercury (Hg2+) effects on biofilm formation by clinical and environmental isolates of Klebsiella pneumoniae.

The increase in urbanization and industrialization has contributed to the contamination of different environments by means of xenobiotic compounds, such as heavy metals, causing changes in microbial communities. Among these metals, the Mercury (Hg2+) is one the most prevalent toxic metals for the environment The present study aimed to evaluate the effect of mercury on the formation of biofilm by environmental (collected from urban stream water) and clinical isolates of Klebsiella pneumoniae. In addition, antibiotic resistance, virulence factors, and genetic diversity were investigated. Taxonomic identity of eight isolates (one reference, two clinical, and five environmental isolates) was performed by MALDI-TOF-MS, while the antibiotic susceptibility profile was assessed by the disc diffusion method. The ability to form biofilms was evaluated by culture on Congo red agar and by crystal violet staining. Biofilm structure was analyzed by scanning electron microscopy. The hydrophobicity profile and the presence of the virulence genes cps, fimH, and mrkD was investigated. The presence of merA and its relationship with antimicrobial resistance were also assessed. The identity of all isolates was confirmed by MALDI-TOF-MS, and different profiles of resistance to mercury and antibiotics as well as of biofilm formation were identified for the clinical and environmental isolates. All isolates were hydrophilic and positive for the virulence genes cps, fimH, and mrkD; only the clinical isolate K36-A2 was positive for merA. The diversity of the isolates was confirmed by ERIC-PCR, which revealed high heterogeneity among the isolates. In conclusion, the data demonstrate that the investigated isolates present different responses to exposure to Hg2+ and correspond to distinct populations of K. pneumoniae disseminated in the investigated environment. The data obtained in this work will aid in understanding the mechanisms of survival of this pathogen under adverse conditions.

High plasmid variability, and the presence of IncFIB, IncQ, IncA/C, IncHI1B, and IncL/M in clinical isolates of Klebsiella pneumoniae with bla KPC and bla NDM from patients at a public hospital in Brazil.

INTRODUCTION: Antibiotic resistance in carbapenemase-producing Klebsiella pneumoniae is acquired and disseminated mainly by plasmids. Therefore, we aimed to investigate the occurrence of carbapenemase genes, analyze the genetic diversity by ERIC-PCR, and examine the most common plasmid incompatibility groups (Incs) in clinical isolates of K. pneumoniae from colonization and infection in patients from a hospital in Brazil. METHODS: Twenty-seven isolates of carbapenem-resistant K. pneumoniae were selected and screened for the presence of carbapenemase genes and Incs by PCR, followed by amplicon sequencing. RESULTS: The bla KPC and bla NDM genes were detected in 24 (88.8 %) and 16 (59.2 %) of the isolates, respectively. Thirteen isolates (48.1 %) were positive for both genes. The IncFIB (92.6 %) and IncQ (88.8 %) were the most frequent plasmids, followed by IncA/C, IncHI1B, and IncL/M, indicating that plasmid variability existed in these isolates. To our knowledge, this is the first report of IncHI1B in Brazil. We found eight isolates with clonal relationship distributed in different sectors of the hospital. CONCLUSIONS: The accumulation of resistance determinants, the variability of plasmid Incs, and the clonal dissemination detected in K. pneumoniae isolates demonstrate their potential for infection, colonization, and the dissemination of different resistance genes and plasmids.

Association of blaNDM-1 with blaKPC-2 and aminoglycoside-modifying enzyme genes among Klebsiella pneumoniae, Proteus mirabilis and Serratia marcescens clinical isolates in Brazil.

OBJECTIVES: Carbapenemase-producing Enterobacterales are frequently involved in healthcare-associated infections worldwide. The objectives of this study were to investigate (i) the frequency of the main genes encoding carbapenemases, 16S rRNA methylases and aminoglycoside-modifying enzymes (AMEs) as well as the mcr gene and (ii) the clonal relationship of enterobacteria isolates resistant to carbapenems and aminoglycosides from colonisation and infection in patients from hospitals in northeastern Brazil. METHODS: Antimicrobial susceptibility was determined using an automated VITEK®2 system. Presence of carbapenemase, AME and 16S rRNA methylase genes as well as the mcr gene was determined by PCR and amplicon sequencing. Genetic variability was determined by ERIC-PCR. RESULTS: A total of 35 isolates resistant to carbapenems and aminoglycosides were selected for this study. Klebsiella pneumoniae was most common (45.7%), followed by Proteus mirabilis (28.6%) and Serratia marcescens (25.7%). AME genes were found in 97.1% of isolates, most commonly aph(3')-VI and aac(6')-Ib. The blaNDM-1 and blaKPC-2 genes were detected in 25.7% and 88.6% of isolates, respectively; five isolates harboured these genes concomitantly. According to the literature, this is the first report of the association of blaNDM-1 and blaKPC-2 in P. mirabilis and S. marcescens in Brazil. The isolates showed a multiclonal profile by ERIC-PCR. CONCLUSION: The emergence of blaNDM-1 associated with blaKPC-2 and AME genes in K. pneumoniae, P. mirabilis and S. marcescens isolates with a multiclonal profile is of concern as this limits therapeutic options. These results should alert medical authorities to establish rigorous detection methods to reduce the spread of these antimicrobial resistance genes.

Emergence of aph(3')-VI and accumulation of aminoglycoside modifying enzyme genes in KPC-2-possessing Enterobacter aerogenes isolates from infections and colonization in patients from Recife-PE, Brazil.

INTRODUCTION: The objective of this study was to characterize genes of aminoglycoside modifying enzymes (AMEs) in colonizing and infecting isolates of E. aerogenes harboring bla KPC from patients at a public hospital in Recife-PE, Brazil. METHODS: We analyzed 29 E. aerogenes clinical isolates resistant to aminoglycosides. AMEs genes were investigated by PCR and sequencing. RESULTS: Colonizing and infecting isolates mainly presented the genetic profiles aac(3)-IIa/aph(3')-VI or ant(2")-IIa/aph(3')-VI. This is the first report of aph(3')-VI in E. aerogenes harboring bla KPC in Brazil. CONCLUSIONS: The results highlight the importance in establishing rigorous methods for the surveillance of resistance genes, especially in colonized patients.

Occurrence of qnrB1 and qnrB12 genes, mutation in gyrA and ramR, and expression of efflux pumps in isolates of Klebsiella pneumoniae carriers of blaKPC-2.

PURPOSE: The occurrence of quinolone-resistance genes (qnrA, qnrB and qnrS), the presence of mutations in gyrA, gyrB and parC, as well as the expression of efflux pumps (acrB and acrF) and mutations in the gene ramR. METHODOLOGY: Were investigated in 30 blaKPC-2-positive isolates of Klebsiella pneumoniae taken from infection and colonization in hospital patients from Recife-PE, Brazil. The detection of the qnr, acrB and acrF genes and analysis of the mutations in ramR and the quinolone-resistance-determining regions of gyrA, gyrB and parC were performed by PCR followed by DNA sequencing. RESULTS: Among the isolates analysed, 73.3 % (n=22) presented the qnrB gene. For the DNA sequencing, six isolates (K3-A2, K12-A2, K25-A2, K27-A2, K19-A2 and K3-C2) were selected and the qnrB1 and qnrB12 variants were detected. This is the first ever report, to the best of our knowledge, of the presence of qnrB12 in K. pneumoniae. This is also the first report, to the best of our knowledge, of the presence of qnrB1 or qnrB12 with blaKPC-2 in K. pneumoniae in Brazil. Mutations were observed in gyrA S83 and in ramR. All isolates presented genes for the acrB and acrF efflux pumps and the reverse transcription PCR performed showed that the pumps were being expressed. CONCLUSION: KPC-2-positive isolates colonizing patients, which also showed qnrB, mutation in gyrA and efflux pumps, may be important reservoirs for disseminating these resistance mechanisms in the hospital environment.

Clonal spread and accumulation of ß-lactam resistance determinants in Enterobacter aerogenes and Enterobacter cloacae complex isolates from infection and colonization in patients at a public hospital in Recife, Pernambuco, Brazil.

Enterobacter aerogenes and Enterobacter cloacae complex are the two species of this genus most involved in healthcare-associated infections that are ESBL and carbapenemase producers. This study characterized, phenotypically and genotypically, 51 isolates of E. aerogenes and E. cloacae complex originating from infection or colonization in patients admitted to a public hospital in Recife, Pernambuco, Brazil, by antimicrobial susceptibility profile, analysis of ß-lactamase genes (blaTEM, blaSHV, blaCTX-M, blaKPC, blaVIM, blaIMP and blaSPM), PCR and DNA sequencing, plasmid profile and ERIC-PCR. In both species, the genes blaTEM, blaCTX-M and blaKPC were detected. The DNA sequencing confirmed the variants blaTEM-1, blaCTX-M-15 and blaKPC-2 in isolates. More than one gene conferring resistance in the isolates, including the detection of the three previously cited genes in strains isolated from infection sites, was observed. The detection of blaCTX-M was more frequent in isolates from infection sites than from colonization. The gene blaKPC predominated in E. cloacae complex isolates obtained from infections; however, in E. aerogenes isolates, it predominated in samples obtained from colonization. A clonal relationship among all of E. aerogenes isolates was detected by ERIC-PCR. The majority of E. cloacae complex isolates presented the same ERIC-PCR pattern. Despite the clonal relation presented by the isolates using ERIC-PCR, different plasmid and resistance profiles and several resistance genes were observed. The clonal dissemination and the accumulation of ß-lactam resistance determinants presented by the isolates demonstrated the ability of E. aerogenes and E. cloacae complex, obtained from colonization and infection, to acquire and maintain different resistance genes.

Ultrastructural changes caused by polymyxin B and meropenem in multiresistant Klebsiella pneumoniae carrying blaKPC-2 gene.

The ultrastructural alterations caused by polymyxin B and meropenem and by the association between polymyxin B and meropenem were investigated in two multiresistant isolates of Klebsiella pneumoniae (K3-A2 and K12-A2) carriers of blaKPC-2, coming from infection and colonization in patients in a public hospital in Recife, Brazil. The ultrastructural changes were detected by transmission electron microscopy and scanning. The susceptibility of the isolates to antimicrobials was tested by the disc diffusion method and microdilution in broth. The analysis by electron microscopy showed that the isolates presented morphological and ultrastructural cellular changes when subjected to a clinically relevant concentration of antimicrobials alone or in combination. When subjected to meropenem, they presented retraction of the cytoplasmic material, rupture of the cell wall and extravasation of the cytoplasmic content. When submitted to polymyxin B, the isolates showed condensation of the ribosomes, DNA clotting, cell wall thickening and the presence of membrane compartment. When subjected to polymyxin B and meropenem in combination, the isolates showed a higher intensity of the ultrastructural changes visualized. This is the first report of the ultrastructural changes caused by polymyxin B and meropenem in multiresistant isolates of K. pneumoniae carriers of the blaKPC-2 gene. It should be noted that even when the K. pneumoniae isolates were multiresistant carriers of the blaKPC-2 gene, they underwent important structural change owing to the action of polymyxin B and meropenem.

KPC-PRODUCING Serratia marcescens IN A HOME-CARE PATIENT FROM RECIFE, BRAZIL.

In this brief communication we describe the occurrence of a KPC-producing Serratia marcescens isolate in a home-care patient from Recife, Brazil. The blaKPC, blaSPM, blaIMP, blaVIM, blaOXA, blaCTX-M, blaSHV, blaTEM and blaGES genes were investigated by Polymerase Chain Reaction (PCR) and DNA sequencing. The isolate was positive for blaKPC-2 and blaTEM-1 and was resistant to aztreonam, cefepime, cefotaxime, imipenem, meropenem, gentamicin, ciprofloxacin and cefazidime, and susceptible only to amikacin, tigecycline and gatifloxacin. This is the first report in Brazil of KPC-producing S. marcescens clinical isolate outside of a hospital environment. Caregivers should be alert for the presence of this isolate in the community setting.

Detection of bla KPC-2 in Proteus mirabilis in Brazil.

INTRODUCTION: Infections caused by Klebsiella pneumoniae carbapenemase (KPC)-producing isolates pose a major worldwide public health problem today. METHODS: A carbapenem-resistant Proteus mirabilis clinical isolate was investigated for plasmid profiles and the occurrence of ß-lactamase genes. RESULTS: The isolate exhibited resistance to ertapenem and imipenem and was susceptible to meropenem, polymyxin, and tigecycline. Five plasmids were identified in this isolate. DNA sequencing analysis revealed the presence of bla KPC-2 and bla TEM-1 genes. An additional PCR using plasmid DNA confirmed that bla KPC-2 was present in one of these plasmids. CONCLUSIONS: We report the detection of bla KPC-2 in P. mirabilis in Brazil for the first time. This finding highlights the continuous transfer of bla KPC between bacterial genera, which presents a serious challenge to the prevention of infection by multidrug-resistant bacteria.

High plasmid variability, and the presence of IncFIB, IncQ, IncA/C, IncHI1B, and IncL/M in clinical isolates of Klebsiella pneumoniae with bla KPC and bla NDM from patients at a public hospital in Brazil

Abstract INTRODUCTION Antibiotic resistance in carbapenemase-producing Klebsiella pneumoniae is acquired and disseminated mainly by plasmids. Therefore, we aimed to investigate the occurrence of carbapenemase genes, analyze the genetic diversity by ERIC-PCR, and examine the most common plasmid incompatibility groups (Incs) in clinical isolates of K. pneumoniae from colonization and infection in patients from a hospital in Brazil. METHODS Twenty-seven isolates of carbapenem-resistant K. pneumoniae were selected and screened for the presence of carbapenemase genes and Incs by PCR, followed by amplicon sequencing. RESULTS The bla KPC and bla NDM genes were detected in 24 (88.8 %) and 16 (59.2 %) of the isolates, respectively. Thirteen isolates (48.1 %) were positive for both genes. The IncFIB (92.6 %) and IncQ (88.8 %) were the most frequent plasmids, followed by IncA/C, IncHI1B, and IncL/M, indicating that plasmid variability existed in these isolates. To our knowledge, this is the first report of IncHI1B in Brazil. We found eight isolates with clonal relationship distributed in different sectors of the hospital. CONCLUSIONS The accumulation of resistance determinants, the variability of plasmid Incs, and the clonal dissemination detected in K. pneumoniae isolates demonstrate their potential for infection, colonization, and the dissemination of different resistance genes and plasmids.

Emergence of aph(3')-VI and accumulation of aminoglycoside modifying enzyme genes in KPC-2-possessing Enterobacter aerogenes isolates from infections and colonization in patients from Recife-PE, Brazil

Abstract INTRODUCTION: The objective of this study was to characterize genes of aminoglycoside modifying enzymes (AMEs) in colonizing and infecting isolates of E. aerogenes harboring bla KPC from patients at a public hospital in Recife-PE, Brazil. METHODS: We analyzed 29 E. aerogenes clinical isolates resistant to aminoglycosides. AMEs genes were investigated by PCR and sequencing. RESULTS: Colonizing and infecting isolates mainly presented the genetic profiles aac(3)-IIa/aph(3')-VI or ant(2")-IIa/aph(3')-VI. This is the first report of aph(3')-VI in E. aerogenes harboring bla KPC in Brazil. CONCLUSIONS: The results highlight the importance in establishing rigorous methods for the surveillance of resistance genes, especially in colonized patients.

Investigation of class 1 integrons in Klebsiella pneumoniae clinical and microbiota isolates belonging to different phylogenetic groups in Recife, State of Pernambuco.

INTRODUCTION: The high prevalence of Klebsiella pneumoniae infections is related to the ability of K. pneumoniae to acquire and disseminate exogenous genes associated with mobile elements, such as R plasmids, transposons and integrons. This study investigated the presence of class 1 integrons in clinical and microbiota isolates of K. pneumoniae belonging to different phylogenetic groups and correlated these results with the antimicrobial resistance profiles of the studied isolates. METHODS: Of the 51 isolates of K. pneumoniae selected for this study, 29 were from multidrug-resistant clinical isolates, and 22 were from children's microbiota. The susceptibility profile was determined using the disk diffusion method, and class 1 integrons were detected through polymerase chain reaction (PCR). RESULTS: The results showed that none of the 22 microbiota isolates carried class 1 integrons. Among the 29 clinical isolates, 19 (65.5%) contained class 1 integrons, and resistance to sulfamethoxazole/trimethoprim was identified in 18 of these isolates (94.7%). Among the K. pneumoniae isolates with class 1 integrons, 47% belonged to the KpI phylogenetic group, and one isolate (14.3%) carrying these genetic elements belonged to the KpIII group. CONCLUSIONS: The wide variety of detected class 1 integrons supports the presence of high rates of antimicrobial resistance, genetic variability, and rapid dissemination of beta-lactamase genes among K. pneumoniae clinical isolates in recent years in hospitals in Recife-PE, Brazil. The findings of this study indicate that the surveillance of K. pneumoniae integrons in clinical isolates could be useful for monitoring the spread of antibiotic resistance genes in the hospital environment.

Phenotypic and molecular characterization of antimicrobial resistance and virulence factors in Pseudomonas aeruginosa clinical isolates from Recife, State of Pernambuco, Brazil.

INTRODUCTION: The emergence of carbapenem resistance mechanisms in Pseudomonas aeruginosa has been outstanding due to the wide spectrum of antimicrobial degradation of these bacteria, reducing of therapeutic options. METHODS: Sixty-one clinical strains of P. aeruginosa isolated from five public hospitals in Recife, Pernambuco, Brazil, were examined between 2006 and 2010, aiming of evaluating the profiles of virulence, resistance to antimicrobials, presence of metallo-ß-lactamase (MBL) genes, and clonal relationship among isolates. RESULTS: A high percentage of virulence factors (34.4% mucoid colonies; 70.5% pyocyanin; 93.4% gelatinase positives; and 72.1% hemolysin positive) and a high percentage of antimicrobial resistance rates (4.9% pan-resistant and 54.1% multi-drug resistant isolates) were observed. Among the 29 isolates resistant to imipenem and/or ceftazidime, 44.8% (13/29) were MBL producers by phenotypic evaluation, and of these, 46.2% (6/13) were positive for the blaSPM-1 gene. The blaIMP and blaVIM genes were not detected. The molecular typing revealed 21 molecular profiles of which seven were detected in distinct hospitals and periods. Among the six positive blaSPM-1 isolates, three presented the same clonal profile and were from the same hospital, whereas the other three presented different clonal profiles. CONCLUSIONS: These results revealed that P. aeruginosa is able to accumulate different resistance and virulence factors, making the treatment of infections difficult. The identification of blaSPM-1 genes and the dissemination of clones in different hospitals, indicate the need for stricter application of infection control measures in hospitals in Recife, Brazil, aiming at reducing costs and damages caused by P. aeruginosa infections.

Multidrug resistance genes, including bla(KPC) and bla(CTX)-M-2, among Klebsiella pneumoniae isolated in Recife, Brazil.

INTRODUCTION: The prevalence of cephalosporins and carbapenem-resistant Klebsiella pneumoniae strains is rising in Brazil, with potential serious consequences in terms of patients' outcomes and general care. METHODS: This study characterized 24 clinical isolates of K. pneumoniae from two hospitals in Recife, Brazil, through the antimicrobial susceptibility profile, analyses of ß-lactamase genes (bla(TEM), bla(SHV),bla(CTX-M), bla(KPC), bla(VIM), bla(IMP), and bla(SPM), plasmidial profile and ERIC-PCR (Enterobacterial repetitive intergenic consensus-polymerase chain reaction). RESULTS: ERIC-PCR and plasmidial analysis grouped the isolates in 17 and 19 patterns, respectively. Six isolates from one hospital presented the same pattern by ERIC-PCR, indicating clonal dissemination. All isolates presented bla(SHV), 62.5% presented bla(CTX)-M-2, 29% bla(TEM), and 41.7% bla(KPC). Metallo-ß-lactamase genes bla(VIM), bla(IMP), and bla(SPM) not detected. Eleven isolates were identified carrying at least 3 ß-lactamase studied genes, and 2 isolates carried bla(SHV), bla(TEM), bla (CTX-M-2) and bla(KPC) simultaneously. CONCLUSIONS: The accumulation of resistance genes in some strains, observed in this study, imposes limitations in the therapeutic options available for the treatment of infections caused by K. pneumoniae in Recife, Brazil. These results should alert the Brazilian medical authorities to establish rigorous methods for more efficiently control the dissemination of antimicrobial resistance genes in the hospital environment.

Investigation of class 1 integrons in Klebsiella pneumoniae clinical and microbiota isolates belonging to different phylogenetic groups in Recife, State of Pernambuco

Introduction The high prevalence of Klebsiella pneumoniae infections is related to the ability of K. pneumoniae to acquire and disseminate exogenous genes associated with mobile elements, such as R plasmids, transposons and integrons. This study investigated the presence of class 1 integrons in clinical and microbiota isolates of K. pneumoniae belonging to different phylogenetic groups and correlated these results with the antimicrobial resistance profiles of the studied isolates. Methods Of the 51 isolates of K. pneumoniae selected for this study, 29 were from multidrug-resistant clinical isolates, and 22 were from children's microbiota. The susceptibility profile was determined using the disk diffusion method, and class 1 integrons were detected through polymerase chain reaction (PCR). Results The results showed that none of the 22 microbiota isolates carried class 1 integrons. Among the 29 clinical isolates, 19 (65.5%) contained class 1 integrons, and resistance to sulfamethoxazole/trimethoprim was identified in 18 of these isolates (94.7%). Among the K. pneumoniae isolates with class 1 integrons, 47% belonged to the KpI phylogenetic group, and one isolate (14.3%) carrying these genetic elements belonged to the KpIII group. Conclusions The wide variety of detected class 1 integrons supports the presence of high rates of antimicrobial resistance, genetic variability, and rapid dissemination of beta-lactamase genes among K. pneumoniae clinical isolates in recent years in hospitals in Recife-PE, Brazil. The findings of this study indicate that the surveillance of K. pneumoniae integrons in clinical isolates could be useful for monitoring the spread of antibiotic resistance genes in the hospital environment. .

Multidrug resistance genes, including blaKPC and blaCTX-M-2, among Klebsiella pneumoniae isolated in Recife, Brazil / Genes de multirresistência, incluindo blaKPC e blaCTX-M-2, em Klebsiella pneumoniae isoladas em Recife, Brasil

INTRODUCTION: The prevalence of cephalosporins and carbapenem-resistant Klebsiella pneumoniae strains is rising in Brazil, with potential serious consequences in terms of patients' outcomes and general care. METHODS: This study characterized 24 clinical isolates of K. pneumoniae from two hospitals in Recife, Brazil, through the antimicrobial susceptibility profile, analyses of β-lactamase genes (blaTEM, blaSHV,blaCTX-MblaKPC, blaVIM, blaIMP, and blaSPM), plasmidial profile and ERIC-PCR (Enterobacterial repetitive intergenic consensus-polymerase chain reaction). RESULTS: ERIC-PCR and plasmidial analysis grouped the isolates in 17 and 19 patterns, respectively. Six isolates from one hospital presented the same pattern by ERIC-PCR, indicating clonal dissemination. All isolates presented blaSHV, 62.5% presented blaCTX-M-2, 29% blaTEM, and 41.7% blaKPC. Metallo-β-lactamase genes blaand blawere not detected. Eleven isolates were identified carrying at least 3 β-lactamase studied genes, and 2 isolates carried blaSHVblaTEM, blaCTX-M-2 and blaKPC simultaneously. CONCLUSIONS: The accumulation of resistance genes in some strains, observed in this study, imposes limitations in the therapeutic options available for the treatment of infections caused by K. pneumoniae in Recife, Brazil. These results should alert the Brazilian medical authorities to establish rigorous methods for more efficiently control the dissemination of antimicrobial resistance genes in the hospital environment.

INTRODUÇÃO: A prevalência de cepas de Klebsiella pneumoniae resistentes a cefalosporinas e carbapenêmicos está aumentando no Brasil, com sérias consequências em termos de desfechos dos pacientes e cuidados gerais. MÉTODOS: Este estudo caracterizou 24 isolados clínicos de K. pneumoniae provenientes de dois hospitais de Recife, Brasil, através do perfil de susceptibilidade a antimicrobianos, análise de genes de β-lactamase (blaTEM,blaSHV,blaCTX-MblaKPC,blaVIM, blaIMP,and blaSPM), perfil plasmidial e ERIC-PCR (Enterobacterial repetitive intergenic consensus-polymerase chain reaction). RESULTADOS: A análise da ERIC-PCR e do perfil plasmidial agrupou os isolados em 17 e 19 perfis, respectivamente. Seis isolados de um hospital apresentaram o mesmo padrão de ERIC-PCR, indicando disseminação clonal. Todos os isolados apresentaram blaSHV, 62,5% apresentaram blaCTX-M-2, 29% blaTEM e 41,7% blaKPC. Genes de metalo-β-lactamase blaVIM, blaIMP e blaSPM não foram detectados. Onze isolados foram identificados carreando, pelo menos, três dos genes de β-lactamase estudados, dentre estes, dois isolados continham blaSHV,blaTEM, blaCTX-M-2 e blaKPC simultaneamente. CONCLUSÕES: O acúmulo de genes de resistência em algumas cepas, observado nesse estudo, impõem limitações nas opções terapêuticas disponíveis para o tratamento de infecções causadas por K. pneumoniae em Recife, Brasil. Estes resultados devem alertar as autoridades médicas brasileiras para estabelecer rigorosos métodos para controlar eficientemente a disseminação de genes de resistência a antimicrobianos no ambiente hospitalar.

Phenotypic and molecular characterization of antimicrobial resistance and virulence factors in Pseudomonas aeruginosa clinical isolates from Recife, State of Pernambuco, Brazil / Caracterização fenotípica e molecular de fatores de resistência a antimicrobianos e virulência de isolados clínicos de Pseudomonas aeruginosa de Recife, Estado de Pernambuco, Brasil

INTRODUCTION: The emergence of carbapenem resistance mechanisms in Pseudomonas aeruginosa has been outstanding due to the wide spectrum of antimicrobial degradation of these bacteria, reducing of therapeutic options. METHODS: Sixty-one clinical strains of P. aeruginosa isolated from five public hospitals in Recife, Pernambuco, Brazil, were examined between 2006 and 2010, aiming of evaluating the profiles of virulence, resistance to antimicrobials, presence of metallo-β-lactamase (MBL) genes, and clonal relationship among isolates. RESULTS: A high percentage of virulence factors (34.4% mucoid colonies; 70.5% pyocyanin; 93.4% gelatinase positives; and 72.1% hemolysin positive) and a high percentage of antimicrobial resistance rates (4.9% pan-resistant and 54.1% multi-drug resistant isolates) were observed. Among the 29 isolates resistant to imipenem and/or ceftazidime, 44.8% (13/29) were MBL producers by phenotypic evaluation, and of these, 46.2% (6/13) were positive for the blaSPM-1 gene. The blaIMP and blaVIM genes were not detected. The molecular typing revealed 21 molecular profiles of which seven were detected in distinct hospitals and periods. Among the six positive blaSPM-1 isolates, three presented the same clonal profile and were from the same hospital, whereas the other three presented different clonal profiles. CONCLUSIONS: These results revealed that P. aeruginosa is able to accumulate different resistance and virulence factors, making the treatment of infections difficult. The identification of blaSPM-1 genes and the dissemination of clones in different hospitals, indicate the need for stricter application of infection control measures in hospitals in Recife, Brazil, aiming at reducing costs and damages caused by P. aeruginosa infections.

INTRODUÇÃO: A emergência de mecanismos de resistência aos carbapenêmicos em Pseudomonas aeruginosa tem se destacado devido ao amplo espectro de degradação de antimicrobianos, reduzindo as opções terapêuticas. MÉTODOS: Sessenta e um isolados de P. aeruginosa procedentes de cinco hospitais públicos de Recife, Pernambuco, Brasil, entre 2006 e 2010, foram analisadas, com o objetivo de avaliar o perfil de virulência, resistência aos antimicrobianos, a presença de genes metalo-β-lactamase (MBL) e a relação clonal entre os isolados. RESULTADOS: Foi observada uma elevada produção de fatores de virulência na amostra (34,4% colônias mucoides; 70,5% piocianina; 93,4% gelatinase e 72,1% hemolisina), bem como um elevado percentual de resistência (4,9% isolados panresistentes e 54,1% multirresistentes). Dentre os 29 isolados resistentes ao imipenem e/ou ceftazidima, 44,8% (13/29) apresentaram MBL por meio da pesquisa fenotípica, e destes, 46,2% (6/13) foram positivos para o gene blaSPM-1, não havendo detecção dos genes blaIMP e blaVIM. A tipagem molecular revelou 21 perfis genéticos dos quais sete foram detectados em hospitais e períodos distintos, e dos isolados blaSPM-1 positivos, três apresentaram o mesmo perfil clonal e foram procedentes do mesmo hospital, enquanto que os outros três isolados blaSPM-1 positivos apresentaram perfis clonais distintos. CONCLUSÕES: Estes resultados revelam que a P. aeruginosa é capaz de acumular diferentes fatores de virulência e resistência, dificultando o tratamento das infecções. A identificação de genes blaSPM-1 e disseminação de clones sugere a necessidade de aplicação mais rigorosa de medidas de controle de infecção nos hospitais de Recife, visando reduzir custos e danos provocados por este tipo de infecção.