Emerging threat: Antimicrobial resistance proliferation during epidemics - A case study of the SARS-CoV-2 pandemic in South Brazil.

The escalating global concern of antimicrobial resistance poses a significant challenge to public health. This study delved into the occurrence of resistant bacteria and antimicrobial resistance genes in the waters and sediments of urban rivers and correlated this emergence and the heightened use of antimicrobials during the COVID-19 pandemic. Isolating 45 antimicrobial-resistant bacteria across 11 different species, the study identifies prevalent resistance patterns, with ceftriaxone resistance observed in 18 isolates and ciprofloxacin resistance observed in 13 isolates. The detection of extended-spectrum ß-lactamases, carbapenemases, and acquired quinolone resistance genes in all samples underscores the gravity of the situation. Comparison with a pre-pandemic study conducted in the same rivers in 2019 reveals the emergence of previously undetected new resistant species, and the noteworthy presence of new resistant species and alterations in resistance profiles among existing species. Notably, antimicrobial concentrations in rivers increased during the pandemic, contributing significantly to the scenario of antimicrobial resistance observed in these rivers. We underscore the substantial impact of heightened antimicrobial usage during epidemics, such as COVID-19, on resistance in urban rivers. It provides valuable insights into the complex dynamics of antimicrobial resistance in environmental settings and calls for comprehensive approaches to combat this pressing global health issue, safeguarding both public and environmental health.

Clinical and microbiological profile of health care-associated infections in a tertiary hospital: Comparison between a cohort of hospitalized patients during prepandemic and COVID-19 pandemic periods.

BACKGROUND: During the COVID-19 pandemic, health service practices underwent significant changes, impacting the occurrence of health care-associated infections (HAIs). This study presents the epidemiology of bacterial infections and compares clinical data on nosocomial infections in hospitalized patients before and during the pandemic. METHODS: A unicentric, observational, retrospective cohort study was conducted with descriptive analyses on the microorganism identification and resistance profile. Patient's clinical data who had hospital-acquired infection (HAI), during their hospitalization in a tertiary hospital before and during the COVID-19 pandemic was compared by descriptive and inferential analyses. RESULTS: A total of 1,581 bacteria were isolated from 1,183 hospitalized patients. Among patients coinfected with COVID-19, there was a statistically significant increase in HAI-related deaths (P < .001) and HAI caused by multidrug-resistant organisms (P < .001), mainly by Acinetobacter baumannii and Staphylococcus aureus. A higher odds ratio of HAI-related deaths compared to the prepandemic period was observed (odds ratio 6.98 [95% confidence interval 3.97-12.64]). CONCLUSIONS: The higher incidence of multidrug-resistant bacteria and increased deaths due to HAI, especially in patients with COVID-19 coinfection, might be related to various factors such as increased workload, broad-spectrum antibiotic use, and limited resources. The pandemic has changed the profile of circulating bacteria and antimicrobial resistance. Prevention strategies should be considered to reduce the impact of these infections.

Predictive factors, outcomes, and molecular epidemiology of Clostridioides difficile diarrhea in Brazilian hospitals.

Little is known about the role of lineage of strains of Clostridioides difficile (CD) on the clinical presentation of CD infection (CDI) in Latin America, especially regarding the treatment response. We conducted a multicenter, prospective study to investigate the predictive factors and treatment outcomes of CDI in hospitalized patients and to performed phenotypical and molecular characterization of CD strains. A total of 361 diarrheic patients at 5 hospitals from different regions of the country were enrolled. All stool samples were tested for glutamate dehydrogenase (GDH), toxins A and B, and toxin genes using a nucleic acid amplification test (NAAT). Specimens were cultured and susceptibility profile and whole-genome sequencing (WGS) were performed. CDI positivity was 15% (56/377). Predictive factors for CDI were prior use of meropenem (OR 4.09, 95% CI 2.097-7.095; p<0.001), mucus in stools (OR 3.29; 95% CI 1.406-7.722; p=0.006) and neutrophil left-shift with >20% of bands (OR 3.77; 95% IC 1.280-11.120; p=0.016). Overall mortality was 19%, with no deaths attributed to CDI. Oral metronidazole was used in 74% of cases, with 85% of cure and 14% of recurrence. A total of 35 CD isolates were recovered, all of them susceptible to metronidazole and vancomycin. The WGS revealed 17 different STs, six of which were novel. ST42 was the most common ST and hypervirulent strains were not found. Severe CDI were caused by ST42, ST5, ST8, ST48, ST33 and a novel ST667. The ermB gene was more frequently found in isolates of ST42 (p=0.004).

The Xpert® MTB/RIF diagnostic test for pulmonary and extrapulmonary tuberculosis in immunocompetent and immunocompromised patients: Benefits and experiences over 2 years in different clinical contexts.

Xpert® MTB/RIF has been widely used for tuberculosis (TB) diagnosis in Brazil, since 2014. This prospective observational study aimed to evaluate the performance of Xpert in different contexts during a two-year period: (i) laboratory and clinical/epidemiological diagnosis; (ii) HIV-positive and -negative populations; (iii) type of specimens: pulmonary and extrapulmonary. Overall, 924 specimens from 743 patients were evaluated. The performance of the assays was evaluated considering culture (Lowenstein Jensen or LJ medium) results and composite reference standard (CRS) classification as gold standard. According to CRS evaluation, 219 cases (29.5%) were classified as positive cases, 157 (21.1%) as 'possible TB', and 367 (49.3%) as 'not TB'. Based on culture, Xpert and AFB smear achieved a sensitivity of 96% and 62%, respectively, while based on CRS, the sensitivities of Xpert, AFB smear, and culture were 40.7%, 20%, and 25%, respectively. The pooled sensitivity and specificity of Xpert were 96% and 94%, respectively. Metric evaluations were similar between pulmonary and extrapulmonary samples against culture, whereas compared to CRS, the sensitivities were 44.6% and 29.3% for the pulmonary and extrapulmonary cases, respectively. The Xpert detected 42/69 (60.9%) patients with confirmed TB and negative culture on LJ medium, and 52/69 (75.4%) patients with negative AFB smear results. There was no significant difference in the diagnostic accuracy based on the types of specimens and population (positive- and negative-HIV). Molecular testing detected 13 cases of TB in culture-negative patients with severe immunosuppression. Resistance to rifampicin was detected in seven samples. Herein, Xpert showed improved detection of pulmonary and extrapulmonary TB cases, both among HIV-positive and -negative patients, even in cases with advanced immunosuppression, thereby performing better than multiple other diagnostic parameters.

Prevalence of Clostridioides difficile associated diarrhea in hospitalized patients in five Brazilian centers: A multicenter, prospective study.

Epidemiological data on CD infection (CDI) in Latin American are scarce. CDI prevalence and strains characterization were prospectively evaluated in 5 Brazilian hospitals from different regions. Prevalence rates of CDI were 15%, ranging from 0 to 37%. ST42 was the most common Sequence Type and hypervirulent strains were not identified.

Brucella Laboratory Exposures in Brazil: Rare or Unnoticed?

Laboratory exposures to Brucella spp. are preventable. After an outbreak in Brazil, human brucellosis was made statutorily reportable as well as laboratory accidents. After the implementation of this law, three laboratorial accidents with Brucella abortus were reported in a Brazilian city, and 58 workers were exposed from January 2019 to April 2020. We describe the exposure level, prophylaxis, and serosurvey after 6 months, and we highlight the importance of disease report.

Antimicrobial activity of plazomicin against Enterobacteriaceae-producing carbapenemases from 50 Brazilian medical centers.

Plazomicin is a next-generation aminoglycoside with activity against Enterobacteriaceae, including carbapenemase-producing Enterobacteriaceae (CPE). The aim of this study was to evaluate the activity of plazomicin against CPE (Klebsiella spp., Escherichia coli, Serratia spp., Enterobacter spp., Citrobacter spp., Morganella spp., Proteus spp., Providencia spp.) from different Brazilian hospitals. A total of 4000 carbapenem-resistant Enterobacteriaceae isolates were collected from clinical samples in 50 Brazilian hospitals during 2013-2015. Of these, 499 carbapenem-resistant isolates (CLSI criteria) were selected for further evaluation via broth microdilution to assess for the activity of plazomicin, colistin, tigecycline, meropenem, amikacin, and gentamicin. Additionally, the isolates were assessed for the presence of carbapenemase genes (blaKPC, blaNDM, blaOXA-48-like, blaIMP, blaBKC, blaGES, and blaVIM) by polymerase chain reaction (PCR). When PCR was positive to blaOXA-48-like, blaIMP, blaGES, and blaVIM, the carbapenemase genes were sequenced. blaKPC was the most prevalent carbapenemase gene found (n=397), followed by blaNDM (n=81), blaOXA-48 (n=12), and blaIMP-1 (n=3). Other genes were identified in only 1 isolate each: blaBKC-1, blaGES-16, blaGES-1, blaOXA-370, and blaVIM-1. One isolate had 2 carbapenemase genes (blaKPC and blaNDM). Thirty-three percent of the isolates were nonsusceptible to colistin, 24% to tigecycline, 97% to meropenem, 51% to amikacin, and 81% to gentamicin (via EUCAST criteria). The plazomicin MIC50/90 was 0.5/64mg/L, with 85% of MICs ≤2mg/L and 87% of MICs ≤4mg/L. Elevated MICs to plazomicin were not associated with a specific carbapenemase or bacterial species. The MICs of plazomicin against CPE were lower than those of other aminoglycosides. Plazomicin is a promising drug for the treatment of CPE infections.

Characterization of CTX-M enzymes, quinolone resistance determinants, and antimicrobial residues from hospital sewage, wastewater treatment plant, and river water.

Multidrug-resistant (MDR) bacteria are widespread in hospitals and have been increasingly isolated from aquatic environments. The aim of the present study was to characterize extended-spectrum ß-lactamase (ESBL) and quinolone-resistant Enterobacteriaceae from a hospital effluent, sanitary effluent, inflow sewage, aeration tank, and outflow sewage within a wastewater treatment plant (WWTP), as well as river water upstream and downstream (URW and DRW, respectively), of the point where the WWTP treated effluent was discharged. ß-lactamase (bla) genes, plasmid-mediated quinolone resistance (PMQR), and quinolone resistance-determining regions (QRDRs) were assessed by amplification and sequencing in 55 ESBL-positive and/or quinolone-resistant isolates. Ciprofloxacin residue was evaluated by high performance liquid chromatography. ESBL-producing isolates were identified in both raw (n=29) and treated (n=26) water; they included Escherichia coli (32), Klebsiella pneumoniae (22) and Klebsiella oxytoca (1). Resistance to both cephalosporins and quinolone was observed in 34.4% of E. coli and 27.3% of K. pneumoniae. Resistance to carbapenems was found in 5.4% of K. pneumoniae and in K. oxytoca. Results indicate the presence of blaCTX-M (51/55, 92.7%) and blaSHV (8/55, 14.5%) ESBLs, and blaGES (2/55, 3.6%) carbapenemase-encoding resistance determinants. Genes conferring quinolone resistance were detected at all sites, except in the inflow sewage and aeration tanks. Quinolone resistance was primarily attributed to amino acid substitutions in the QRDR of GyrA (47%) or to the presence of PMQR (aac-(6')-Ib-cr, oqxAB, qnrS, and/or qnrB; 52.9%) determinants. Ciprofloxacin residue was absent only from URW. Our results have shown strains carrying ESBL genes, PMQR determinants, and mutations in the gyrA QRDR genes mainly in hospital effluent, URW, and DRW samples. Antimicrobial use, and the inefficient removal of MDR bacteria and antibiotic residue during sewage treatment, may contribute to the emergence and spreading of resistance in the environment, making this a natural reservoir.

Phenotypic and genotypic characterization of group B streptococcal isolates in southern Brazil.

One-hundred sixty-eight group B streptococcal (GBS) isolates from a Brazilian hospital were phenotypically and genotypically characterized. Isolates were recovered from human sources from April 2006 to May 2008 and classified as either invasive, noninvasive, or colonizing isolates. Classical methods for serotyping and antibiotic resistance profiling were employed. Clonal groups were also defined by pulsed-field gel electrophoresis (PFGE). Results showed that susceptibility to beta-lactam antimicrobials was predominant among the isolates. Only 4.7% were resistant to erythromycin and clindamycin. The erm(B) gene was widely detected in our GBS isolates, according to our phenotypic results (constitutive macrolide-lincosamide-streptogramin B [cMLSB] resistance phenotype), and the erm(A) gene was also detected in some isolates. MLSB resistance was restricted to strains isolated from patients with noninvasive infections and carriers. Serotype Ia was predominant (38.1%), serotype IV isolates were found at a high frequency (13.1%), and few isolates of serotype III were identified (3%). Pulsed-field gel electrophoresis results revealed a variety of types, reflecting the substantial genetic diversity among GBS strains, although a great number of isolates could be clustered into two major groups with a high degree of genetic relatedness. Three main PFGE clonal groups were found, and isolates sharing the same PFGE type were grouped into different serotypes. Furthermore, in a few cases, isolates from the same patients and possessing the same PFGE type were of different serotypes. These findings could be related to the occurrence of capsular switching by horizontal transfer of capsular genes.