Antimicrobial resistance and epidemic clustering of late-onset neonatal infections in a Brazilian intensive care unit.

Nosocomial infections in the neonatal intensive care unit (NICU) tend to cluster and multidrug-resistant (MDR) pathogens are rising in developing countries. We did a retrospective cohort study of neonates admitted to a NICU in Brazil with late-onset neonatal sepsis (LOS) confirmed by blood culture from October 2012 to December 2016 and from July 2018 to December 2021. We defined a cluster of infection when at least two cases of LOS occurred within two different time intervals: 15 and 30 days with the same pathogen in different patients. A random amplified polymorphic DNA (RAPD) was performed from samples from one of these clusters. A logistic regression model was applied having death as the outcome and the infection with an MDR pathogen as the exposure of interest. There were 987 blood cultures from 754 neonates, 621 (63%) were gram-positive cocci, 264 (30%) were gram-negative rods and 72 (7%) fungi. A third of Enterobacterales were resistant to cefepime and a third of non-fermenting glucose rods were resistant to carbapenems. There were 100 or 104 clusters of infection in the 15- or 30-day interval, respectively. A RAPD analysis from an outbreak of MDR Acinetobacter baumannii showed that all five samples belonged to a single clone. An infection with an MDR pathogen was associated with death (OR 1.82, 95% CI 1.03-3.21). In conclusion, clusters of infections in a Brazilian NICU are a frequent phenomenon as seen elsewhere. They suggest cross-transmission of pathogens with increasing antimicrobial resistance and should prompt intensified surveillance and infection control measures.

Environmental spreading of clinically relevant carbapenem-resistant gram-negative bacilli: the occurrence of blaKPC-or-NDM strains relates to local hospital activities.

BACKGROUND: Aquatic matrices impacted by sewage may shelter carbapenem-resistant (CR) Gram-negative bacilli (GNB) harboring resistance genes of public health concern. In this study, sewage treatment plants (STPs) servicing well-defined catchment areas were surveyed for the presence of CR-GNB bearing carbapenemase genes (blaKPC or blaNDM). RESULTS: A total of 325 CR-GNB were recovered from raw (RS) and treated (TS) sewage samples as well as from water body spots upstream (UW) and downstream (DW) from STPs. Klebsiella-Enterobacter (KE) group amounted to 116 isolates (35.7%). CR-KE isolates were recovered from TS, DW (35.7%) and RS samples (44.2%) (p = 0.001); but not from UW samples. KE isolates represented 65.8% of all blaKPC or blaNDM positive strains. The frequency of blaKPC-or-NDM strains was positively associated with the occurrence of district hospitals located near STPs, as well as with the number of hospitalizations and of sewer connections serviced by the STPs. blaKPC-or-NDM strains were recovered from ST samples in 7 out of 14 STPs, including four tertiary-level STPs; and from 6 out of 13 DW spots whose RS samples also had blaKPC-or-NDM strains. CONCLUSIONS: Clinically relevant GNB bearing blaKPC-or-NDM resist sewage treatments and spread into environmental aquatic matrices mainly from STPs impacted by hospital activities.

Insertion sequences disrupting mgrB in carbapenem-resistant Klebsiella pneumoniae strains in Brazil.

OBJECTIVES: This study aimed to characterise insertional mutations disturbing themgrB gene in carbapenem-resistant Klebsiella pneumoniae (CRKp). METHODS: A total of 118 clinical CRKp isolates were surveyed for polymyxin resistance and insertion sequence (IS) elements disruptingmgrB. RESULTS: Of the 118 isolates, 78 (66.1%) displayed polymyxin resistance, of which 54% (42/78) hadmgrB::IS inserts. Sequencing analyses showed 13 insertion sites in mgrB. mgrB::ISSen4(IS3) was observed for the first time in CRKp. CONCLUSIONS: Ten different IS elements disruptedmgrB, with a predominance (76%) of IS5 sequences.

Avaliação de soluções antibacterianas na descontaminação de escovas dentais de pré-escolares / Evaluation of bacterial solutions in the decontamination of toothbrushes collected from preschool students

O objetivo deste estudo foi avaliar o efeito antimicrobiano de diferentes soluções desinfetantes na descontaminação de escovas dentais de pré-escolares. Foram selecionados aleatoriamente 30 pré-escolares, com idade entre 6-7 anos, de uma escola municipal de Franca-SP. Cada pré-escolar recebeu uma escova dental, que foi utilizada com dentifrício durante cinco dias consecutivos na escovação realizada após a ingestão da merenda escolar. Após a escovação, as escovas foram enxaguadas com água de torneira e borrifadas com água deionizada esterilizada (1), hipoclorito de sódio a 1% (2) e ácido acético a 0,05% (3), sendo uma solução por semana. Ao final de cada semana, cada estudante recebeu uma nova escova, e as já utilizadas eram recolhidas, introduzidas em um tubo de ensaio contendo meio de cultura e encaminhadas ao Laboratório de Microbiologia da Universidade de Franca. As amostras foram sonificadas, diluídas, aliquotadas e semeadas nos seguintes meios de cultura: ágar sangue, ágar Mitis Salivarius e ágar MacConkey. Após o período de incubação, foi realizada a contagem de UFC.mL–1. Houve crescimento de bactérias aeróbias totais em 96,42; 10,34 e 84,61% das amostras quando do uso das soluções 1, 2 e 3 respectivamente, e de estreptococos em 85,71; 10,34 e 76,72% das amostras respectivamente. Não houve recuperação de bacilos Gram-negativos aeróbios nas amostras. Concluiu-se que, com o uso da solução de hipoclorito de sódio a 1%, houve uma significante redução no crescimento bacteriano (p < 0,01), resultando em uma maior eficácia na descontaminação das escovas dentais quando comparada com as outras soluções.

The objective of this study was to evaluate the antimicrobial effect of different disinfectant solutions on the decontamination of kindergarten students’ toothbrushes. Thirty (30) preschool students between 6 and 7 years of age were randomly selected from a municipal school in Franca (SP). Each student received one toothbrush to be used during five days, with toothpaste, in the brushing process after lunchtime. After brushing, the toothbrushes were washed with running tap water and sprayed with: sterilized water (1); sodium hypochlorite 1% (2), and acetic acid 0.05% (3), which were used during one week each. At the end of each week, each student received a new toothbrush, and the used ones were collected, inserted in a tube containing culture media and sent to the Microbiological Laboratory of the University of Franca. The samples were sonicated, aliquotated and plated in the following culture media: blood agar, Mitis Salivarius agar, and MacConkey agar. After the incubation period the CFU.mL–1 was counted. Growth of total aerobic introspecieswas observed in 96.42, 10.34 and 84.61% of the samples with the use of solutions 1, 2, and 3 respectively; and streptococci grew in 85.71, 10.34 and 76.72% of the samples, respectively. No growth of aerobic Gram-negative bacilli was observed. We concluded that the use of sodium hypochlorite solution at 1% caused a significant (p < 0.01) reduction of bacterial growth, resulting in an effective decontamination of the toothbrushes when compared to the other solutions.