Patrícia R. Neves

High Prevalence of bla(CTX-M) Extended Spectrum Beta-Lactamase Genes in Klebsiella pneumoniae Isolates from a Tertiary Care Hospital: First report of bla(SHV-12), bla(SHV-31), bla(SHV-38), and bla(CTX-M-15) in Brazil

The aim of this study was to investigate the presence and prevalence of bla(TEM), bla(SHV), and bla(CTX-M) and bla(GES)-like genes, responsible for extended spectrum beta-lactamases (ESBLs) production in clinical isolates of Klebsiella pneumoniae collected from a Brazilian tertiary care hospital. Sixty-five ESBL producing K. pneumoniae isolates, collected between 2005 and 2007, were screened by polymerase chain reaction (PCR). Identification of bla genes was achieved by sequencing. Genotyping of ESBL producing K. pneumoniae was performed by the enterobacterial repetitive intergenic consensus-PCR with cluster analysis by the Dice coefficient. The presence of genes encoding ESBLs was confirmed in 59/65 (90.8%) isolates, comprising 20 bla(CTX-M-2), 14 bla(CTX-M-59), 12 bla(CTX-M-15), 9 bla(SHV-12), 1 bla(SHV-2), 1 bla(SHV-2a), 1 bla(SHV-5), and 1 bla(SHV-31) genes. The ESBL genes bla(SHV-12), bla(SHV-31), and bla(CTX-M-15), and the chromosome-encoded SHV-type beta-lactamase capable of hydrolyzing imipenem were detected in Brazil for the first time. The analysis of the enterobacterial repetitive intergenic consensus-PCR band patterns revealed a high rate of multiclonal bla(CTX-M) carrying K. pneumoniae isolates (70.8%), suggesting that dissemination of encoding plasmids is likely to be the major cause of the high prevalence of these genes among the K. pneumoniae isolates considered in this study.

Low Prevalence of blaOXA-143 in Private Hospitals in Brazil

We read with great interest C. S. Antonio et al.s letter describing the high prevalence of Acinetobacter baumannii carrying bla OXA-143 in Brazilian hospitals ([1][1]). Recently, we carried out a similar study, and although the bla OXA-143 gene was identified, its frequency was lower than that

Emergence of carbapenem-resistant Escherichia coli producing CMY-2-type AmpC beta-lactamase in Brazil.

Carbapenem-resistant Escherichia coli isolates have not been described to date in South America. However, the emergence of Shigella flexneri and Klebsiella pneumoniae isolates producing CMY-2type plasmid-mediated AmpC was recently reported in Argentina (Radice et al., 2007; Rapoport et al., 2008). Here, we report the emergence of carbapenemresistant E. coli producing CMY-2-type AmpC b-lactamase in Brazil, confirming that CMY-2-producing strains have already become established in Latin America.

Pseudomonas aeruginosa multirresistente: um problema endêmico no Brasil

Global reports have documented the endemicity of multidrug-resistant (MDR) Pseudomonas aeruginosa associated with high levels of morbidity/mortality. In Brazil, outbreaks of MDR P. aeruginosa have been related to clonal dissemination. Currently, therapeutic options for the treatment of these infections are restricted to carbapenemic antibiotics (i.e., imipenem [IPM]). Thus, carbapenem resistance is a public health issue, since carbapenems are considered the last resort to nosocomial infections caused by MDR Gram-negative bacteria. In Brazil, the main mechanisms associated with MDR P. aeruginosa phenotypes are metallo-betalactamase (MBL) production (SPM-1 enzyme), presence of 16S rRNA methylase RmtD, loss of OprD porin, and overexpression of efflux pumps, which may explain the high level of carbapenem and aminoglycoside resistance. Accordingly, the emergence and dissemination of MDR strains is worrisome. Finally, based on national reports published by different groups of investigators, it is deduced that the convergence of multiple mechanisms of P. aeruginosa resistance has played a major role in the selection of endemic MDR clones widespread in Brazil.

Identification of fluoroquinolone-resistant extended-spectrum β-lactamase (CTX-M-8)-producing Escherichia coli ST224, ST2179 and ST2308 in buffalo (Bubalus bubalis)

D2 differed from one another by fewer than five single nucleotide differences, but only the WM98 sequence was not interrupted by large insertions or deletions (positions of insertions/deletions are indicated in Figure 1). AB307-0294 (GenBank accession number CP001172) was also identical over most of this span, but contained patches that differed and lacked a large span. The AB0057 sequence (GenBank accession number CP001182), for which the ampC gene was previously corrected, differed at 33 more positions (single base substitutions or additions or deletions; mainly the absence of an A or a T in a run of As or Ts) and many of these differences may be errors caused by the sequencing technology used. Contigs containing ampC and its surrounds were retrieved from the whole genome sequence of G7 reported previously 6 and joined using the manually determined sequence described above. Comparison with the WM98 sequence revealed a segment of 31.8 kb, defined as between the first and last base differences surrounding the ISAba1-ampC in G7, which differed from the corresponding region in WM98 by 2.2% (Figure 1). This indicates that this segment has been replaced by a segment imported from another A. baumannii strain that included an ISAba1 upstream of the ampC gene. Hence, it appears that a DNA segment that included an ISAba1-activated ampC gene was introduced into an isolate belonging to the GC1 clonal complex, possibly by conjugation , and that homologous recombination incorporated it into the chromosome displacing the resident copy. Examination of the regions on either side of the 31.8 kb diverged segment revealed the presence of two smaller replaced patches of 4.7 and 2.8 kb in G7, which differed from the corresponding regions in WM98 by 4.5% and 2.1%, respectively (Figure 1). Outside these patches, WM98 and G7 differed by only 3 bp. This is the first study providing evidence for horizontal transfer of a DNA segment that contains an ISAba1-activated ampC gene between two A. baumannii strains. The findings highlight the significance of the horizontal transfer of chromosomal DNA segments in the generation of cephalosporin resistance in A. baumannii. 3 Hamidian M, Hall RM. Tn6168, a transposon carrying an ISAba1-activated ampC gene and conferring cephalosporin resistance in Acinetobacter baumannii. 4 Hamidian M, Hall RM. ISAba1 targets a specific position upstream of the intrinsic ampC gene of Acinetobacter baumannii leading to cephalosporin resistance. ISAba125-activated ampC gene between Acinetobacter baumannii strains leading to cephalosporin resistance. A …

Balanoposthitis caused by Pseudomonas aeruginosa co-producing metallo-β-lactamase and 16s rRNA methylase in children with hematological malignancies.

Balanoposthitis is defined as the inflammation of the glans penis and its foreskin. In the presence of other underlying medical conditions, this localized infection may spread systemically, serving as a source of fever and bacteremia in neutropenic males. Two rare cases of balanoposthitis caused by a clonally related Pseudomonas aeruginosa isolate co-producing the SPM-1 metallo-beta-lactamase and the novel 16S rRNA methylase RmtD are described. Four multidrug-resistant (MDR) P. aeruginosa isolates were successively recovered from glans/foreskin swabs and urine cultures from two uncircumcised pediatric patients, one with Burkitts non-Hodgkins lymphoma and one with acute lymphoblastic leukemia. Clinically, preputial colonization by MDR P. aeruginosa evolved to severe balanoposthitis with glans/foreskin lesions as a source of fever. Combination therapy of ciprofloxacin and/or aztreonam (systemic) plus polymyxin B (topical) was effective once reversion of the neutropenic condition was achieved. Although P. aeruginosa remains an unusual cause of balanoposthitis, these cases should alert the physician to the potential pathogenicity of this bacterium. Furthermore, co-production of metallo-beta-lactamase and 16S rRNA methylase has a potential impact on the empirical management of complicated infections caused by P. aeruginosa.

Low-virulence phylogenetic background of CTX-M-producing Escherichia coli isolated from extraintestinal infections.

1 Department of Microbiology, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo, Brazil 2 Department of Clinical Analysis, School of Pharmacy, Universidade de São Paulo, São Paulo, Brazil 3 Department of Preventive Medicine and Animal Health, College of Veterinary Medicine, Universidade de São Paulo, São Paulo, Brazil 4 Faculty of Biotechnology, Institute of Biological Sciences, Universidade Federal do Pará, Belém-PA, Brazil 5 Department of Pathology, College of Veterinary Medicine, Universidade de São Paulo, São Paulo, Brazil

Complete Genome Sequence of an F8-Like Lytic Myovirus (φSPM-1) That Infects Metallo-β-Lactamase-Producing Pseudomonas aeruginosa

ABSTRACT Pseudomonas aeruginosa is an important cause of infection, especially in immunocompromised patients. In this regard, strains producing carbapenemases, mainly metallo-β-lactamases (MBLs), have become a significant public health concern. Here, we present the complete annotated genome sequence (65.7 kb) of an F8-related lytic myovirus (Pbunalikevirus genus) that infects MBL-producing P. aeruginosa strains.

High mortality of bloodstream infection outbreak caused by carbapenem-resistant P. aeruginosa producing SPM-1 in a bone marrow transplant unit

PURPOSE Carbapenem resistance in P. aeruginosa is increasing worldwide. In Brazil, SPM-1 is the main P. aeruginosa carbapenemase identified. Little is known about the virulence factor in SPM-1 clones.Methodolgy. We describe a carbapenem-resistant P. aeruginosa bloodstream infection (CRPa-BSI) outbreak in a bone marrow transplant Unit (BMT). Twenty-nine CRPa-BSI cases were compared to 58 controls. Microbiological characteristics of isolates, such as sensitivity, carbapenemase gene PCR for P. aeruginosa, and PFGE are described, as well as the whole-genome sequence (WGS) of three strains.Results/Key findings. The cultures from environmental and healthcare workers were negative. Some isolates harboured KPC and SPM. The WGS showed that the 03 strains belonged to ST277, presented the same mutations in outer membrane protein, efflux pump, and virulence genes such as those involved in adhesion, biofilm, quorum-sensing and the type III secretion system, but differ regarding the carbapenemase profile. A predominant clone-producing SPM harbouring Tn 4371 was identified and showed cross-transmission; no common source was found. Overall mortality rate among cases was 79 %. The first multivariate analysis model showed that neutropenia (P=0.018), GVHD prophylaxis (P=0.016) and prior use of carbapenems (P=0.0089) were associated with CRPa-BSI. However, when MASCC>21 points and platelets were added in the final multivariate analysis, only prior use of carbapenems remained as an independent risk factor for CRPa-BSI (P=0.043). CONCLUSIONS The predominant clone belonging to ST277 showed high mortality. Carbapenem use was the only risk factor associated with CRPa-BSI. This finding is a wake-up call for the need to improve management in BMT units.

Clinical and microbiological characteristics of OXA-23- and OXA-143-producing Acinetobacter baumannii in ICU patients at a teaching hospital, Brazil

BACKGROUND Carbapenem-resistant Acinetobacter baumannii (CRAb) is an important cause of nosocomial infections especially in intensive care units. This study aimed to assess clinical aspects and the genetic background of CRAb among ICU patients at a Brazilian teaching hospital. METHODS 56 critically ill patients colonized or infected by CRAb, during ICU stay, were prospectively assessed. Based on imipenem MIC≥4μg/mL, 28 CRAB strains were screened for the presence of genes encoding metallo-β-lactamases and OXA-type β-lactamases. The blaOXA-type genes were characterized by PCR using primers targeting ISAba-1 or -3. Genetic diversity of blaOXA-positive strains was determined by ERIC-PCR analysis. RESULTS Patients mean age (±SD) was 61 (±15.1), and 58.9% were male. Eighty-percent of the patients presented risk factors for CRAb colonization, mainly invasive devices (87.5%) and previous antibiotic therapy (77.6%). Thirty-three patients died during hospital stay (59.0%). Resistance to carbapenems was associated with a high prevalence of blaOXA-23 (51.2%) and/or blaOXA-143 (18.6%) genes. ERIC-PCR genotyping identified 10 clusters among OXA-producing CRAb. Three CRAb strains exhibited additional resistance to polymyxin B (MIC≥4μg/mL), whereas 10 CRAb strains showed tigecycline MICs>2μg/mL. CONCLUSIONS In this study, clonally unrelated OXA-123- and OXA-143-producing A. baumannii strains in ICU patients were strongly correlated to colonization with infected patients being associated with a poor outcome.