Antimicrobial susceptibility and emerging resistance determinants (blaCTX-M, rmtB, fosA3) in clinical isolates from urinary tract infections in the Bolivian Chaco

Summary Background Bolivia is among the lowest-resourced South American countries, with very few data available on antibiotic resistance in bacterial pathogens. The phenotypic and molecular characterization of bacterial isolates responsible for urinary tract infections (UTIs) in the Bolivian Chaco are reported here. Methods All clinical isolates from UTIs collected in the Hospital Basico Villa Montes between June 2010 and January 2014 were analyzed ( N =213). Characterization included susceptibility testing, extended-spectrum beta-lactamase (ESBL) detection, identification of relevant resistance determinants (e.g., CTX-M-type ESBLs, 16S rRNA methyltransferases, glutathione S-transferases), and genotyping of CTX-M producers. Results Very high resistance rates were observed. Overall, the lowest susceptibility was observed for trimethoprim–sulphamethoxazole, tetracycline, nalidixic acid, amoxicillin–clavulanic acid, ciprofloxacin, and gentamicin. Of E. coli and K. pneumoniae , 11.6% were ESBL producers. Resistance to nitrofurantoin, amikacin, and fosfomycin remained low, and susceptibility to carbapenems was fully preserved. CTX-M-15 was the dominant CTX-M variant. Four E. coli ST131 (two being H30-Rx) were identified. Of note, isolates harbouring rmtB and fosA3 were detected. Conclusions Bolivia is not an exception to the very high resistance burden affecting many South American countries. Optimization of alternative approaches to monitor local antibiotic resistance trends in resource-limited settings is strongly encouraged to support the implementation of effective empiric treatment guidelines

Proposal for a New Score-Based Approach To Improve Efficiency of Diagnostic Laboratory Workflow for Acute Bacterial Meningitis in Adults

Microbiological tests on cerebrospinal fluid (CSF) utilize a common urgent-care procedure that does not take into account the chemical and cytological characteristics of the CSF, resulting sometimes in an unnecessary use of human and diagnostic resources. The aim of this study was to retrospectively validate a simple scoring system (bacterial meningitis-Careggi score [BM-CASCO]) based on blood and CSF sample chemical/cytological parameters for evaluating the probability of acute bacterial meningitis (ABM) in adults. BM-CASCO (range, 0 to 6) was defined by the following parameters: CSF cell count, CSF protein levels, CSF lactate levels, CSF glucose-to-serum glucose ratio, and peripheral neutrophil count. BM-CASCO was retrospectively calculated for 784 cases of suspected ABM in adult subjects observed during a four-and-a-half-year-period (2010 to 2014) at the emergency department (ED) of a large tertiary-care teaching hospital in Italy. Among the 28 confirmed ABM cases (3.5%), Streptococcus pneumoniae was the most frequent cause (16 cases). All ABM cases showed a BM-CASCO value of ≥3. Most negative cases (591/756) exhibited a BM-CASCO value of ≤1, which was adopted in our laboratory as a cutoff to not proceed with urgent microbiological analysis of CSF in cases of suspected ABM in adults. During a subsequent 1-year follow-up, the introduction of the BM-CASCO in the diagnostic workflow of ABM in adults resulted in a significant decrease in unnecessary microbiological analysis, with no false negatives. In conclusion, BM-CASCO appears to be an accurate and simple scoring system for optimization of the microbiological diagnostic workflow of ABM in adults

Methicillin-resistant Staphylococcus aureus in hospitalized patients from the Bolivian Chaco

Summary Objectives Information is lacking on the methicillin-resistant Staphylococcus aureus (MRSA) clonal lineages circulating in Bolivia. We investigated the prevalence and molecular epidemiology of S. aureus colonization in hospitalized patients from the Bolivian Chaco, and compared their features with those of the few clinical isolates available from that setting. Methods S. aureus nasal/inguinal colonization was investigated in 280 inpatients from eight hospitals in two point prevalence surveys (2012, n =90; 2013, n =190). Molecular characterization included genotyping ( spa typing, multilocus sequence typing, and pulsed-field gel electrophoresis), detection of virulence genes, and SCC mec typing. Results Forty-one inpatients (14.6%) were S. aureus nasal/inguinal carriers, of whom five were colonized by MRSA (1.8%). MRSA isolates mostly belonged to spa- type t701, harboured SCC mec IVc, and were negative for Panton–Valentine leukocidin (PVL) genes. However, a USA300-related isolate was also detected, which showed the characteristics of the USA300 Latin American variant (USA300-LV; i.e., ST8, spa- type t008, SCC mec IVc, presence of PVL genes, absence of arc A). Notably, all the available MRSA clinical isolates ( n =5, collected during 2011–2013) were also identified as USA300-LV. Conclusions Overall, MRSA colonization in inpatients from the Bolivian Chaco was low. However, USA300-LV-related isolates were detected in colonization and infections, emphasizing the importance of implementing control measures to limit their further dissemination in this resource-limited area

Low prevalence of methicillin-resistant Staphylococcus aureus nasal carriage in urban and rural community settings in Bolivia and Peru☆

Summary Objective To investigate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage in rural and urban community settings of Bolivia and Peru. Methods MRSA nasal carriage was investigated in 585 individuals living in rural and urban areas of Bolivia and Peru (one urban area, one small rural village, and two native communities, one of which was highly isolated). MRSA isolates were subjected to molecular analysis for the detection of virulence genes, characterization of the staphylococcal cassette chromosome mec (SCC mec ), and genotyping (multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE)). Results An overall very low prevalence of MRSA nasal carriage was observed (0.5%), with MRSA carriers being detected only in a small rural village of the Bolivian Chaco. The three MRSA isolates showed the characteristics of community-associated MRSA (being susceptible to all non-beta-lactam antibiotics and harboring the SCC mec type IV), were clonally related, and belonged to ST1649. Conclusions This study provides an insight into the epidemiology of MRSA in community settings of Bolivia and Peru. Reliable, time-saving, and low-cost methods should be implemented to encourage continued surveillance of MRSA dissemination in resource-limited countries

Pathogenic mosaic variants in congenital hypogonadotropic hypogonadism

PURPOSE Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder resulting in absent puberty and infertility. The genetic architecture is complex with multiple loci involved, variable expressivity, and incomplete penetrance. The majority of cases are sporadic, consistent with a disease affecting fertility. The current study aims to investigate mosaicism as a genetic mechanism for CHH, focusing on de novo rare variants in CHH genes. METHODS We evaluated 60 trios for de novo rare sequencing variants (RSV) in known CHH genes using exome sequencing. Potential mosaicism was suspected among RSVs with altered allelic ratios and confirmed using customized ultradeep sequencing (UDS) in multiple tissues. RESULTS Among the 60 trios, 10 probands harbored de novo pathogenic variants in CHH genes. Custom UDS demonstrated that three of these de novo variants were in fact postzygotic mosaicism-two in FGFR1 (p.Leu630Pro and p.Gly348Arg), and one in CHD7 (p.Arg2428*). Statistically significant variation across multiple tissues (DNA from blood, buccal, hair follicle, urine) confirmed their mosaic nature. CONCLUSIONS We identified a significant number of de novo pathogenic variants in CHH of which a notable number (3/10) exhibited mosaicism. This report of postzygotic mosaicism in CHH patients provides valuable information for accurate genetic counseling

Intravenous methylprednisolone pulses in hospitalised patients with severe COVID-19 pneumonia, A double-blind, randomised, placebo-controlled trial

Rationale: Pulse glucocorticoid therapy is used in hyperinflammation related to coronavirus 2019 (COVID-19). We evaluated the efficacy and safety of pulse intravenous methylprednisolone in addition to standard treatment in COVID-19 pneumonia. Methods: In this multicenter, randomised, double-blind, placebo-controlled trial, 304 hospitalised patients with Covid-19 pneumonia were randomised to receive 1 g of methylprednisolone intravenously for 3 consecutive days or placebo in addition to standard dexamethasone. The primary outcome was the duration of the patient hospitalisation, calculated as the time interval between randomisation and hospital discharge without the need of supplementary oxygen. The key secondary outcomes were survival free from invasive ventilation with orotracheal intubation and overall survival. Results: Overall, 112 of 151 (75.4%) patients in the pulse methylprednisolone arm and 111 of 150 (75.2%) in the placebo arm were discharged from hospital without oxygen within 30 days from randomisation. Median time to discharge was similar in both groups [15 days (95% confidence interval (CI), 13.0 to 17.0) and 16 days (95%CI, 13.8 to 18.2); hazard ratio (HR), 0.92; 95% CI 0.71-1.20; p=0.528]. No significant differences between pulse methylprednisolone and placebo arms were observed in terms of admission to Intensive Care Unit with orotracheal intubation or death (20.0% versus 16.1%; HR, 1.26; 95%CI, 0.74-2.16; p=0.176), or overall mortality (10.0% versus 12.2%; HR, 0.83; 95%CI, 0.42-1.64; p=0.584). Serious adverse events occurred with similar frequency in the two groups. Conclusions: Methylprenisolone pulse therapy added to dexamethasone was not of benefit in patients with COVID-19 pneumonia. Message of the study: Pulse glucocorticoid therapy is used for severe and/or life threatening immuno-inflammatory diseases. The addition of pulse glucocorticoid therapy to the standard low dose of dexamethasone scheme was not of benefit in patients with COVID-19 pneumonia