The COVID-19 pandemic has generated an overuse of antimicrobials in critically ill patients. Acinetobacter baumannii frequently causes nosocomial infections, particularly in intensive care units (ICUs), where the incidence has increased over time. Since the WHO declared the COVID-19 pandemic on 12 March 2020, the disease has spread rapidly, and many of the patients infected with SARS-CoV-2 needed to be admitted to the ICU. Bacterial co-pathogens are commonly identified in viral respiratory infections and are important causes of morbidity and mortality. However, we cannot neglect the increased incidence of antimicrobial resistance, which may be attributed to the excess use of antimicrobial agents during the COVID-19 pandemic. Patients with COVID-19 could be vulnerable to other infections owing to multiple comorbidities with severe COVID-19, prolonged hospitalization, and SARS-CoV-2-associated immune dysfunction. These patients have acquired secondary bacterial infections or superinfections, mainly bacteremia and urinary tract infections. This review will summarize the prevalence of A. baumannii coinfection and secondary infection in patients with COVID-19.

Objective: The present study was undertaken to characterize CTX-M ESBL-producing Klebsiella pneumoniae collected from hospitals in different cities of Brazil. Material and Methods: Eighty-five K. pneumoniae strains isolated from hospitalized patients in six different hospitals of three cities of Brazil were analyzed. ESBL production was confirmed by the standard double-disk synergy test and the Etest®. The MIC 50 and MIC 90 for ESBL-producing isolates were determined by the Etest® method. The antimicrobial susceptibilities of bacterial isolates were determined using the agar diffusion method according to the CLSI. Screening for bla TEM, bla SHV, bla CTX-M genes and class 1 integron was performed by PCR amplification. To determine the genomic diversity of CTX-M-producers, isolates were analyzed by macrorestriction profile analysis following PFGE. Results and Discussion: Seventy-one K. pneumoniae isolates were ESBL-producing. PCR and sequencing experiments detected 38 CTX-M-producing K. pneumoniae belonged to groups CTX-M 1, CTX-M 2, CTX-M 8 and CTX-M 9. The association of different types ESBL (CTX-M, SHV and TEM) was frequent. All K. pneumoniae isolates carried class 1 integron. PFGE analysis revealed thirty-one clonal types among CTX-M-producing isolates. The data presented herein illustrate the diversity of genotypes of CTX-M producing K. pneumoniae among Brazilians hospitals.

Introduction: In recent decades, the prevalence of carbapenem-resistant Acinetobacter isolates has increased, and the production of oxacillinase (OXA)-type carbapenemases is the main mechanism underlying resistance. We evaluated OXA production from 114 Acinetobacter isolates collected between March and December 2013 from different clinical specimens of patients in two hospitals (Hospital 1 [n = 61] and Hospital 2 [n = 53]) located in Niterói, Rio de Janeiro, Brazil. We also evaluated the genetic diversity of OXA-producing isolates. Methods: All the isolates were identified through the automated system Vitek II and matrix-assisted laser desorption ionization-time of flight mass spectrometry MALDI-TOF MS as belonging to the A. baumannii-A. calcoaceticus complex. Antimicrobial susceptibility profiles were verified through agar diffusion tests. The presence of OXA-encoding genes was confirmed by PCR. The genetic diversity of isolates positive for carbapenemase production was analyzed through pulsed-field gel electrophoresis. Results: There was a high rate of resistance to carbapenems in the isolates (imipenem: 96%; meropenem: 92%) from both hospitals. Moreover, a high percentage (95.6%) of OXA-23-positive isolates was observed for both hospitals, indicating that this was the main mechanism of carbapenem-resistance among the studied population. In addition, most isolates (96.5%) were positive for bla OXA-51 . A high genetic diversity and a few major genotypes were found among the OXA-23-positive isolates analyzed. Only intra-hospital dissemination was observed. Conclusions: The elevated dissemination of bla OXA-23-like observed among Acinetobacter isolates from both the studied hospitals highlights the need for continuous epidemiological surveillance in these institutions.

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Infections due to multidrug resistant Gram-negative pathogens are of great concern worldwide, as they are frequently associated with high mortality and morbidity rates. The occurrence of Pseudomonas spp. producing Klebsiella pneumoniae carbapenemases (KPCs) imposes a great challenge through treatment course of bloodstream infections (BSIs). Pseudomonas putida has been recognized as an emerging pathogen of healthcare associated infections (HAIs). Therefore, we aimed to report a case of a non-fatal case of peripheral line associated BSI (PLA-BSI) in an immunocompromised host due to P. putida harboring blaKPC-2 gene in Brazil. A P. putida isolate was recovered from a blood culture of a 72-year-old man admitted at a University Hospital, identified by BD Phoenix™ 100 (Becton, Dickinson and Company), causing PLA-BSI. The species identification was confirmed by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) and resistance to carbapenems were confirmed by Epsilometer test (E-test®). Additionally, the presence of important carbapenemases genes (blaKPC, blaNDM, blaOXA-48-like, blaSPM, blaIMP, blaVIM) was investigated by Polymerase Chain Reaction. The bacterial isolate was confirmed as meropenem resistant P. putida harboring blaKPC-2 gene.Thereofre, these fidings suggest that P. putida can work as a reservoir for resistance genes as this bacterium has the ability to disseminate through water-fluids inside hospital and community settings. Moreover, this paper highlights that a frequent and worldwide disseminated mechanism of resistance (blaKPC-2) is currently occurring among uncommon agents of BSI.

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Among its innumerous applications in Bacteriology, the Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) technique is evolving as a powerful tool for bacterial identification and antimicrobial resistance investigation. Publications have evaluated the MALDI-TOF MS performance in the identification of a series of bacterial pathogens, including the most common severe infectious agents, emergent pathogens involved with outbreaks of healthcare-associated infections, rare pathogens, and those whose isolation in culture media is difficult. As compared to conventional methods of bacterial identification, MALDI-TOF MS has proven to be a fast, accurate and cost-effective technique. Currently, MALDI-TOF MS has been used in antimicrobial resistance studies, since it has shown to be an efficient tool in detecting specific resistance mechanisms in bacteria, such as beta-lactamases production, for example. Here, we describe the advances in this growing field of mass spectrometry applied to Bacteriology, including Brazilian contributions.

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