High levels of gut carriage of antimicrobial-resistant Escherichia coli in community settings in Rio de Janeiro, Brazil.

The prevalence and risk factors for gut carriage of antimicrobial-resistant Escherichia coli among individuals living in the community in Rio de Janeiro, Brazil, are unknown. The aim of this study was to determine the prevalence of colonization with antimicrobial-resistant E. coli, including isolates producing ESBL and harboring plasmid-mediated quinolone resistant (PMQR) genes in this community. We performed a cross-sectional study and analyzed fecal specimens of individuals attending outpatient clinics in the city from January 2015 to July 2019. We investigated susceptibility to antimicrobial agents by disc diffusion tests and used PCR to determine ESBL types, PMQR, and the virulence genes that characterize an isolate as extraintestinal pathogenic E. coli (ExPEC). Among the 623 subjects, 212 (34%) carried an isolate resistant to at least one of the tested antimicrobial agents, with the highest frequencies of resistance to ampicillin (26%), trimethoprim-sulfamethoxazole (19%), cefazolin (14%), and ciprofloxacin (CIP, 9%). In addition, 13% (81) of subjects carried a multidrug-resistant-E. coli (MDR-E), including 47 (8% of all isolates) ESBL-producing E. coli (ESBL-E), mainly of CTX-M-8 (15, 32%) and CTX-M-15 (9, 20%) types. PMQR genes were present in 7% (42) of all isolates, including 60% (32) of the 53 resistant to CIP. Previous use of antimicrobial agents, particularly fluoroquinolones, was a risk factor for colonization with MDR-E (25%, 20/81 vs 13%, 70/542, p = 0.01), ESBL-E (28%, 13/47, vs 13%, 77/576, p = 0.01), and resistance to CIP (26%, 14/53, vs 12%, 70/570, p = 0.01). The most pathogenic phylogroups B2, C, and D were 37% of the MDR-E, 30% of the ESBL-E, 38% of the CIP-resistant, and 31% of PMQR gene carrying E. coli isolates. We show that carriage of MDR-E (mostly ESBL-E) reached high levels in the community in Rio de Janeiro, increased by the selection of antimicrobial agents. Much of the resistant E. coli isolates are potential pathogenic strains. The widespread use of antimicrobial agents during the COVID-19 pandemic in Brazil may have worsened this picture.

OXA-181 carbapenemase carried on an IncX3 plasmid in high-risk Escherichia coli ST167 isolated from a traveler returning from Sub-Saharan Africa to Brazil.

This is the first detection and genomic analysis of an OXA-181-carbapenemase-producing E. coli in Brazil, from a traveler returning from Sub-Saharan Africa. The ST167 isolate carries blaOXA-181 inserted in an IncX3 plasmid. This report illustrates the potential role of travelers as silent vectors for dissemination of high-risk resistant clones.

Emergence of mgrB locus deletion mediating polymyxin resistance in pandemic KPC-producing Klebsiella pneumoniae ST15 lineage.

Klebsiella pneumoniae causes a diversity of infections in both healthcare and community settings. This pathogen is showing an increased ability to accumulate antimicrobial resistance and virulence genes, making it a public health concern. Here we describe the whole-genome sequence characteristics of an ST15 colistin-resistant K. pneumoniae isolate obtained from a blood culture of a 79-year-old female patient admitted to a university hospital in Brazil. Kp14U04 was resistant to most clinically useful antimicrobial agents, remaining susceptible only to aminoglycosides and fosfomycin. The colistin resistance in this isolate was due to a ~1.3 kb deletion containing four genes, namely mgrB, yebO, yobH and the transcriptional regulator kdgR. The study isolate presented a variety of antimicrobial resistance genes, including the carbapenemase-encoding gene bla KPC-2, the extended-spectrum beta-lactamase (ESBL)-encoding gene bla SHV-28 and the beta-lactamase-encoding gene bla OXA-1. Additionally, Kp14U04 harboured a multiple stress resistance protein, efflux systems and regulators, heavy metal resistance and virulence genes, plasmids, prophage-related sequences and genomic islands. These features revealed the high potential of this isolate to resist antimicrobial therapy, survive in adverse environments, cause infections and overcome host defence mechanisms.

Prevalence of fluoroquinolone-resistant and broad-spectrum cephalosporin-resistant community-acquired urinary tract infections in Rio de Janeiro: Impact of Escherichia coli genotypes ST69 and ST131.

Uropathogenic Escherichia coli (UPEC) is the leading cause of community-acquired urinary tract infection (CA-UTI). The increasing prevalence of CA-UTI caused by UPEC strains resistant to broad-spectrum drugs complicates clinical management of these infections. Here we assessed the prevalence of antimicrobial drug resistance, genotypes and beta-lactamase genes among UPEC isolated from cases of CA-UTI in Rio de Janeiro, Brazil during November 2015 to determine if the prevalence of drug-resistant CA-UTI is determined by multiple genotypes of resistant UPEC or dissemination of key lineages of UPEC. Among 499 UPEC isolates, 98 (20%) were ciprofloxacin (CIP) resistant and 41 (8%) produced extended-spectrum beta-lactamase (ESBL). Sequence types (ST) 69 and 131 were the most common genotypes, representing 77 (15%) and 42 (8%) of all UPEC isolates, respectively. Of fluoroquinolone-resistant isolates, ST69 and ST131 together accounted for 57%, while of ESBL-producers, ST131 represented 21%. Only 5 (2%) of 255 susceptible isolates belonged to these STs (p < .001). blaCTX-M-15 was detected in 17 (42%) of the 41 ESBL-producing isolates. Comparison with a collection of UPEC isolates obtained a decade earlier from the same community showed that a large proportion (60% and 25%, respectively) of the increase in CA-UTI caused by fluoroquinolone-resistant and ESBL-producing UPEC appears to be due to just two pandemic lineages ST131 and ST69. These findings indicate that much of the prevalence of broad-spectrum drug-resistant CA-UTI in Rio de Janeiro is due to a limited set of pandemic lineages of UPEC circulating in the community instead of multiple genotypes selected by antimicrobial agents.