Occurrence of blaKPC gene in clinical isolates of Pseudomonas aeruginosa from Brazil

Pseudomonas aeruginosa is one of the main microorganisms causing healthcarerelated infections. The rise of carbapenem-resistant P. aeruginosa (CRPA) strains has become a serious public health problem. Dissemination of the enzyme Klebsiella pneumoniae carbapenemase (KPC) encoded by the blaKPC gene cause the inactivation of ß-lactam antibiotics being one of the mechanisms involved in this resistance. Given the above, the objective of this review was to evaluate the occurrence of the blaKPC gene in clinical isolates of P. aeruginosa in Brazil. For this, the online databases used were: Lilacs, SciELO and PubMed. The search for articles included articles published from 2012 to 2020, using the following keywords: blaKPC (KPC), Pseudomonas aeruginosa, and Brazil (in Portuguese and English). Initially, 30 publications eligible for inclusion in this review were identified. After the first analysis, two articles were excluded due to duplication. Subsequently, titles and abstracts were evaluated, 15 articles were excluded because they did not fit the theme, and 13 articles that met the inclusion criteria were read in full. In these studies, the presence of the blaKPC gene was investigated in 566 clinical isolates of P. aeruginosa in Brazil, with 86 (15.2%) positive samples found. Pernambuco was the state with the highest number of articles and positive samples, respectively, 38.5% (5/13), and 65.1% (56/86). This study reinforces the need to investigate the occurrence of this gene in all regions of the country in CRPA, aiming to understand how its dissemination occurs and to promote prevention and therapeutic strategies.

First report of the aac(6)-Ib-cr gene in Providencia stuartii isolates in Brazil

Abstract INTRODUCTION: The aac(6')-Ib-cr and bla KPC genes are spreading among Enterobacteriaceae species, including Providencia stuartii, in some countries of world. METHODS: These genes were investigated in 28 P. stuartii isolates from a public hospital in Recife, Pernambuco, Brazil, by PCR and sequencing. RESULTS: The aac(6')-Ib-cr gene was detected in 16 resistant isolates, and the bla KPC gene was seen in 14. CONCLUSIONS: The presence of these genes in P. stuartii multi- and extensively drug-resistant isolates indicates that the resistance arsenal of this species is increasing, thus limiting the therapeutic options.

Phenotypic and genotypic analysis of biofilm production by Pseudomonas aeruginosa isolates from infection and colonization samples

Abstract INTRODUCTION: Pseudomonas aeruginosa is an opportunistic pathogen associated with healthcare-related infections, affecting mainly patients with underlying diseases and immunosuppression. This microorganism has several virulence mechanisms that favour its pathogenesis, including the production of biofilm. This study aimed to analyze the phenotypic production of biofilms, the occurrence of quorum sensing (QS) genes, and the clonal profile of clinical isolates of P. aeruginosa from colonized/infected patients in a tertiary hospital in Recife-PE. METHODS: We obtained 21 isolates that were classified as infection isolates (II), and 10 colonization isolates (CI). The phenotypic analysis for biofilm production was performed quantitatively. The QS genes were detected by specific PCRs, and the clonal profile was assessed using ERIC-PCR. RESULTS: Of the 31 isolates, 58.1 % (18/31) were biofilm producers, of which 70 % (7/10) were CI and classified as weakly adherent; 52.4 % (11/21) of the II produced biofilms, and were classified as weak (38.1 %, (8/21)), moderate (9.5 %, (2/21)), and strongly adherent (4.8 %, (1/21)). All isolates harbored the QS genes analyzed. In the clonal analysis, 26 distinct genetic profiles were identified, highlighting the presence of a clone in four samples, i.e., one infection isolate, and 3 colonization isolates. CONCLUSIONS: The detection of biofilm formation is important in P. aeruginosa in addition to the identification of colonization and infection isolates, especially from complex environments such as ICUs. Further, we define a strategy for monitoring and analyzing P. aeruginosa strains that can potentially cause infections in hospitalized patients.

Occurrence of the vanA gene in Staphylococcus epidermidis from nasopharyngeal secretion of Health-Care Workers, Recife, Brazil

Abstract INTRODUCTION: The increasing reports of vancomycin-resistant Staphylococcus strains (VRS) haves caused concern worldwide, from the laboratory detection to patient management. This study aimed to identify the occurrence of VRS strains among healthcare professionals from a university hospital. METHODS: A total of 102 Staphylococcus sp. isolates from healthcare professionals, obtained in a previous study were evaluated according to standard techniques for VRS detection. RESULTS: After screening inoculation of plates containing 6µg/ml of vancomycin, 19 resistant isolates were identified. The susceptibility profile to other antimicrobials revealed 18 multidrug resistant isolates. The minimum inhibitory concentration (MIC) was determined by E-test and broth microdilution. According to E-tests, of 19 isolates grown in BHI-V6, four isolates presented MIC ≥ 128 µg/ml, seven with MIC ranging from 4 to 8 µg/ml, and eight with MIC ≤ 2µg/ml. By broth microdilution, 14 isolates presented MIC ≤ 2 µg/ml and five with MIC ≥ 16µg/ml. The presence of the gene vanA was determined by PCR in the five resistant isolates, and this gene was detected in one of the strains. Furthermore, among the 19 strains, the gene mecA was found in 13 (39,4%) isolates, including the strain carrying the gene vanA. CONCLUSIONS: Based on these results, we highlight the presence of one strain carrying both vanA and the mecA genes, as well as multidrug-resistant strains colonizing healthcare professionals, and their importance as potential vectors to spread strains carrying resistance genes in the hospital environment.

Biofilm production by clinical isolates of Pseudomonas aeruginosa and structural changes in LasR protein of isolates non biofilm-producing

ABSTRACT Introduction: Biofilm production is an important mechanism for the survival of Pseudomonas aeruginosa and its relationship with antimicrobial resistance represents a challenge for patient therapeutics. P. aeruginosa is an opportunistic pathogen frequently associated to nosocomial infections, especially in imunocompromised hosts. Objectives: Analyze the phenotypic biofilm production in P. aeruginosa isolates, describe clonal profiles, and analyze quorum sensing (QS) genes and the occurrence of mutations in the LasR protein of non-biofilm producing isolates. Methods: Isolates were tested for biofilm production by measuring cells adherence to the microtiter plates. Clonal profile analysis was carried out through ERIC-PCR, QS genes were by specific PCR. Results: The results showed that 77.5% of the isolates were considered biofilm producers. The results of genotyping showed 38 distinct genetic profiles. As for the occurrence of the genes, 100% of the isolates presented the lasR, rhlI and rhlR genes, and 97.5%, presented the lasI gene. In this study nine isolates were not biofilm producers. However, all presented the QS genes. Amplicons related to genes were sequenced in three of the nine non-biofilm-producing isolates (all presenting different genetic similarity profile) and aligned to the sequences of those genes in P. aeruginosa strain PAO1 (standard biofilm-producing strain). Alignment analysis showed an insertion of three nucleotides (T, C and G) causing the addition of an amino acid valine in the sequence of the LasR protein, in position 53. Conclusion: The modeling of the resulting LasR protein showed a conformational change in its structure, suggesting that this might be the reason why these isolates are unable to produce biofilm.

Análise da produção de biofilme por isolados clínicos de Pseudomonas aeruginosa de pacientes com pneumonia associada à ventilação mecânica / Analysis of biofilm production by clinical isolates of Pseudomonas aeruginosa from patients with ventilator-associated pneumonia

RESUMO Objetivo: Avaliar fenotipicamente a produção de biofilme por isolados clínicos de Pseudomonas aeruginosa de pacientes com pneumonia associada à ventilação mecânica. Métodos: Foram analisados 20 isolados clínicos de P. aeruginosa, sendo 19 provenientes de amostras clínicas de aspirado traqueal e uma de lavado broncoalveolar. A avaliação da capacidade de P. aeruginosa em produzir biofilme foi verificada por duas técnicas, sendo uma qualitativa e outra quantitativa. Resultados: A técnica qualitativa mostrou que apenas 15% dos isolados foram considerados produtores de biofilme, enquanto que a quantitativa demonstrou que 75% dos isolados foram produtores de biofilme. Os isolados produtores de biofilme apresentaram o seguinte perfil de suscetibilidade: 53,3% eram multidroga-resistentes e 46,7% eram multidroga-sensíveis. Conclusão: A técnica quantitativa foi mais eficaz para detecção da produção de biofilme em comparação com a qualitativa. Para a população bacteriana analisada, a produção de biofilme independeu do perfil de suscetibilidade das bactérias, demonstrando que a falha terapêutica pode estar relacionada com a produção de biofilme, por impedir a destruição das bactérias presentes nesta estrutura, ocasionando complicações da pneumonia associada à ventilação mecânica, incluindo infecções extrapulmonares, e dificultando o tratamento da infecção.

ABSTRACT Objective: To phenotypically evaluate biofilm production by Pseudomonas aeruginosa clinically isolated from patients with ventilator-associated pneumonia. Methods: Twenty clinical isolates of P. aeruginosa were analyzed, 19 of which were from clinical samples of tracheal aspirate, and one was from a bronchoalveolar lavage sample. The evaluation of the capacity of P. aeruginosa to produce biofilm was verified using two techniques, one qualitative and the other quantitative. Results: The qualitative technique showed that only 15% of the isolates were considered biofilm producers, while the quantitative technique showed that 75% of the isolates were biofilm producers. The biofilm isolates presented the following susceptibility profile: 53.3% were multidrug-resistant, and 46.7% were multidrug-sensitive. Conclusion: The quantitative technique was more effective than the qualitative technique for the detection of biofilm production. For the bacterial population analyzed, biofilm production was independent of the susceptibility profile of the bacteria, demonstrating that the therapeutic failure could be related to biofilm production, as it prevented the destruction of the bacteria present in this structure, causing complications of pneumonia associated with mechanical ventilation, including extrapulmonary infections, and making it difficult to treat the infection.

Phenotypic and molecular characterization of resistance to macrolides, lincosamides and type B streptogramin of clinical isolates of Staphylococcus spp. of a university hospital in Recife, Pernambuco, Brazil

Abstract Introduction There is a mechanism of macrolide resistance in Staphylococcus spp. which also affects the lincosamides and type B streptogramins characterizing the so-called MLSB resistance, whose expression can be constitutive (cMLSB) or inducible (iMLSB) and is encoded mainly by ermA and ermC genes. The cMLSB resistance is easily detected by susceptibility testing used in the laboratory routine, but iMLSB resistance is not. Therapy with clindamycin in cases of infection with isolated iMLSB resistance may fail. Objective To characterize the phenotypic (occurrence of cMLSB and iMLSB phenotypes) and molecular (occurrence of ermA and ermC genes) profiles of MLSB resistance of clinical isolates of susceptible and methicillin-resistant Staphylococcus aureus and CNS (coagulase-negative Staphylococcus) from patients of a university hospital, in Pernambuco. Methods The antimicrobial susceptibility of 103 isolates was determined by the disk diffusion technique in Mueller–Hinton agar followed by oxacillin screening. The iMLSB phenotype was detected by D test. Isolates with cMLSB and iMLSB phenotypes were subjected to polymerase chain reaction (PCR) for the detection of ermA and ermC genes. Results The cMLSB and iMLSB phenotypes were respectively identified in 39 (37.9%) and five (4.9%) isolates. The iMLSB phenotype was found only in four (10.8%) methicillin-susceptible S. aureus and one (4.5%) methicillin-resistant S. aureus. In the 44 isolates subjected to PCR, four (9.1%) only ermA gene was detected, a lower frequency when compared to only ermC 17 (38.6%) gene and to one (2.3%) isolate presenting both genes. Conclusion In the Staphylococcus spp. analyzed, the ermC gene was found more often than the ermA, although the iMLSB phenotype had been less frequent than the cMLSB. It was important to perform the D test for its detection to guide therapeutic approaches.

Infection by multidrug-resistant Elizabethkingia meningoseptica: case reports / Infecção por Elizabethkingia meningoseptica multirresistente: relato de casos

We report two cases of sepsis in critically ill patients in two tertiary care hospitals in Recife-PE, Brazil. The first case is an 87-year-old patient with chronic myeloid leukemia and sepsis; and the second case is a 93-year-old patient with prostate cancer and septic shock caused by multidrug-resistant (MDR) Elizabethkingia meningoseptica.

Reportamos dois casos de sepse em pacientes criticamente debilitados em dois hospitais com nível de complexidade terciária em Recife-PE, Brasil. O primeiro caso, paciente de 87 anos com leucemia mieloide crônica e sepse; o segundo, paciente com 93 anos de idade com câncer de próstata apresentava choque séptico causado por Elizabethkingia meningoseptica multirresistente.