Aims: To investigate the bacterial diversity, antimicrobial resistance patterns and types of beta-lactamase genes in Gram-negative bacteria isolated from a hospital sewage treatment plant. Methods and Results: Between July and December 2008, we collected samples from influent, clarifier tank effluent and chlorine contact tank effluent from a sewage treatment plant service of a hospital located in the city of Rio de Janeiro, Brazil. Of the 221 isolates identified, 40% were characterized as extended-spectrum beta-lactamase (ESBL) producers. Nonpathogenic micro-organisms and some pathogenic genera were quantified. The most common ESBL-producing isolates were Klebsiella pneumoniae, Enterobacter cloacae and Escherichia coli. The bla_TEM, bla_SHV and bla_CTX-M genes were detected in 82, 48 and 67% of bacterial isolates, respectively. Conclusions: Results showed that hospital wastewater treatment plant is not suitable systems for the removal of all antibiotic-resistant micro-organisms present in hospital wastewaters. Significance and Impact of the Study: This study provides evidence that bacteria resistant to multiple antibiotics and their resistance genes that are usually present in the hospital can reach the environment, even after the use of hospital wastewater treatment plants.

To perform molecular epidemiology for 113 KPC-producing Klebsiella pneumoniae isolated in 2010 from 12 Brazilian states. The resistance profile was determined by disc diffusion and Etest. Genetic polymorphism was analysed by PFGE and multilocus sequence typing. The genetic environment of the bla_KPC gene was determined by PCR and identification of the carrier plasmid was determined by hybridization. Most of the isolates were multidrug resistant, with 15% and 49% being resistant to polymyxin and tigecycline, respectively. Twenty-two sequence types (STs) were observed, with ST11, ST437 and ST340 [clonal complex 11 (CC11)] being the most prevalent (75% of isolates) observed in 10 states. bla_KPC-2 was associated with transposon Tn4401 ‘b’ and in 36% this gene was found in IncN plasmids of 40 kb. In Brazil, the spread of bla_KPC-2 is occurring due to dispersion of Tn4401 ‘b’, carried by IncN plasmids of 40 kb, and mainly the dissemination of CC11, with ST437 and ST11 playing an important role.

The bacterial community associated with the midgut of three Brazilian Lutzomyia longipalpis (Lutz & Neiva) populations, two from endemic areas for visceral leishmaniasis (Jacobina, Bahia State and São Luís, Maranhão State) and one from a non-endemic area (Lapinha Cave, Minas Gerais State), was identified. Five groups, 35 females each, from each population were separated; a total of 175 females per collecting area were analyzed. The species identification was based on molecular and traditional bacteriological methods. All bacteria were either affiliated to non-Enterobacteriaceae, such as Acinetobacter, Burkholderia, Flavimonas, Pseudomonas and Stenotrophomonas, or and to Enterobacteriaceae, such as Citrobacter, Enterobacter, Escherichia, Klebsiella, Serratia, Pantoea, Morganella and Weeksella. Stenotrophomonas was found to be associated with all three populations studied. In addition, Serratia spp., which are well documented as laboratory contaminant of insects, were detected only in the Jacobina population. We also discuss the impact of the colonization of insect gut by bacteria on the development and transmission of pathogens.

We aimed to investigate polymyxin B (PMB) resistance and its molecular mechanisms in 126 Klebsiella pneumoniae isolates from rectal swabs in Brazil. Ten isolates exhibited PMB resistance with interruption of mgrB gene by insertion sequences or missense mutations. Most of the PMB-resistant isolates harbored bla _KPC-2 ( n = 8) and belonged to clonal complex 258 (CC258) ( n = 7). These results highlight the importance of monitoring the spread of polymyxin-resistant bacteria in hospitals, since few options remain to treat multidrug-resistant isolates.