Clinical impact of active screening cultures for carbapenem-resistant Acinetobacter baumannii: A systematic review and meta-analysis.

BACKGROUND: Carbapenem-resistant Acinetobacter baumannii (CRAB) has emerged as a significant health care-associated infection carrying substantial mortality. We assessed the clinical impact of active screening cultures for CRAB. METHODS: A systematic review and meta-analysis, aiming to answer 2 questions: (1) Does screening versus no screening improve clinical outcomes? (2) Does positive screening ("CRAB carrier") predict CRAB infections? We searched the literature until January 2024 for comparative studies reporting clinical outcomes (mortality, invasive CRAB infections). RESULTS: Of 5,407 screened publications, 9 studies (10,865 individuals) were included. Invasive CRAB infection rate was significantly higher among CRAB carriers (OR 11.14, 95% CI 4.95-25.05, with substantial heterogeneity stemming from size rather than direction of the effect). Negative predictive value of noncarriage for invasive infection was 97%. CRAB bloodstream infection rate was significantly higher among carriers (odds ratio 16.23, 95% confidence interval 2.9-110.08). No difference was demonstrated between the groups for CRAB ventilator-associated pneumonia, length of stay, and mortality. Only 1 study reported outcomes for study question #1. CONCLUSIONS: Data to support active CRAB screening are scarce regarding its clinical benefit for patients. Positively screened patients are at significantly higher risk for invasive CRAB infections, with high negative predictive value for noncarriage. This did not translate to reduced mortality.

Wastewater Levels of Respiratory Syncytial Virus Associated with Influenza-like Illness Rates in Children-A Case Study in Larissa, Greece (October 2022-January 2023).

The emergence of the COVID-19 pandemic has led to significant progress in the field of wastewater-based surveillance (WBS) of respiratory pathogens and highlighted its potential for a wider application in public health surveillance. This study aimed to evaluate whether monitoring of respiratory syncytial virus (RSV) in wastewater can provide a comprehensive picture of disease transmission at the community level. The study was conducted in Larissa (Central Greece) between October 2022 and January 2023. Forty-six wastewater samples were collected from the inlet of the wastewater treatment plant of Larissa and analyzed with a real-time reverse transcription polymerase chain reaction (RT-PCR) based method. RSV and SARS-CoV-2 wastewater viral loads (genome copies/100,000 inhabitants) were analyzed against sentinel surveillance data on influenza-like illness (ILI) to identify potential associations. Univariate linear regression analysis revealed that RSV wastewater viral load (lagged by one week) and ILI notification rates in children up to 14 years old were strongly associated (std. Beta: 0.73 (95% CI: 0.31-1.14), p = 0.002, R2 = 0.308). A weaker association was found between SARS-CoV-2 viral load and ILI rates in the 15+ age group (std. Beta: 0.56 (95% CI: 0.06-1.05), p = 0.032, R2 = 0.527). The results support the incorporation of RSV monitoring into existing wastewater-based surveillance systems.

Wastewater monitoring as a supplementary surveillance tool for capturing SARS-COV-2 community spread. A case study in two Greek municipalities.

A pilot study was conducted from late October 2020 until mid-April 2021, aiming to examine the association between SARS-CoV-2 RNA concentrations in untreated wastewater and recorded COVID-19 cases in two Greek municipalities. A population of Random Forest and Linear Regression Machine Learning models was trained and evaluated incorporating the concentrations of SARS-CoV-2 RNA in 111 wastewater samples collected from the inlets of two Wastewater Treatment Plants, along with physicochemical parameters of the wastewater influent. The model's predictions were adequately associated with the 7-day cumulative cases with the correlation coefficients (after 5-fold cross validation) ranging from 0.754 to 0.960 while the mean relative errors ranged from 30.42% to 59.46%. Our results provide indications that wastewater-based predictions can be applied in diverse settings and in prolonged time periods, although the accuracy of these predictions may be mitigated. Wastewater-based epidemiology can support and strengthen epidemiological surveillance.

Preparing dental schools to refunction safely during the COVID-19 pandemic: an infection prevention and control perspective.

In late 2019 a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in China and spread throughout the world over a short period of time causing a pandemic of a respiratory disease named coronavirus disease 2019 (COVID-19). SARS-CoV-2 is easily transmitted from person to person through respiratory droplets and direct contact. The scarce available data indicate that dental healthcare personnel are at increased risk for acquisition of infection. Following the lockdown lifting, dental schools should be prepared to refunction safely and provide essential educational and healthcare services while protecting their students, patients, and personnel. The generation of aerosols in dental practice, in association with the high-transmissibility of SARS-CoV-2 through aerosol-generation procedures, the simultaneous provision of dental services to patients in the same areas, and the fact that asymptomatic and pre-symptomatic infected persons may transmit the virus, render the implementation of specific infection prevention and control measures imperative for dental schools. Herein we review the few evidence-based data available to guide infection prevention and control measures for COVID-19 in dental schools.

Evolution of macrolide resistance in Streptococcus pneumoniae clinical isolates in the prevaccine era.

Six hundred twelve invasive and noninvasive Streptococcus pneumoniae isolates were examined. Serogrouping was performed by the latex agglutination test and serotyping by the quellung reaction. Susceptibilities to macrolides were determined by Etest. The presence of mef(A), mef(E), and erm(B) genes were detected by polymerase chain reaction. Outpatient macrolide and lincosamide consumption was expressed in defined daily doses per 1000 inhabitants daily (DID). A significant increase in macrolide resistance rate was noted from 7.4% (14/190) in the period 1985 to 1996 to 53.7% (144/268) in 2001 to 2004 (P = 0.003). An increase in macrolide and lincosamide consumption was also observed from 4.31 +/- 0.72 in 1990 to 1996 to 6.97 +/- 1.02 DID in 2001 to 2004 (P = 0.002). Macrolide resistance was mediated by mef(E) gene in 44.5% of isolates, mef(A) in 25.6%, erm(B) in 19.8%, both erm(B) and mef(E) genes in 4.8%, and none of the examined genes in 5.3%. In the setting of increasing macrolide use, there has been a parallel increase in macrolide resistance among pneumococci in our region. The predominant resistance determinants were the mef(A) and mef(E) genes.

Constitutive soxR mutations contribute to multiple-antibiotic resistance in clinical Escherichia coli isolates.

The soxRS regulon of Escherichia coli and Salmonella enterica is induced by redox-cycling compounds or nitric oxide and provides resistance to superoxide-generating agents, macrophage-generated nitric oxide, antibiotics, and organic solvents. We have previously shown that constitutive expression of soxRS can contribute to quinolone resistance in clinically relevant S. enterica. In this work, we have carried out an analysis of the mechanism of constitutive soxS expression and its role in antibiotic resistance in E. coli clinical isolates. We show that constitutive soxS expression in three out of six strains was caused by single point mutations in the soxR gene. The mutant SoxR proteins contributed to the multiple-antibiotic resistance phenotypes of the clinical strains and were sufficient to confer multiple-antibiotic resistance in a fresh genetic background. In the other three clinical isolates, we observed, for the first time, that elevated soxS expression was not due to mutations in soxR. The mechanism of such increased soxS expression remains unclear. The same E. coli clinical isolates harbored polymorphic soxR and soxS DNA sequences, also seen for the first time.

SoxRS-regulated expression and genetic analysis of the yggX gene of Escherichia coli.

Genomic studies with bacteria have identified redox-responsive genes without known roles in counteracting oxidative damage. Previous transcriptional profiling showed that expression of one such gene, yggX, was activated by superoxide stress in Escherichia coli. Here we show that this activation could be mimicked by artificial expression of the regulatory protein SoxS. Northern analysis confirmed the transcriptional activation of yggX by oxidative stress or SoxS expression but not in response to the related MarA or Rob proteins. Northern analysis showed that mltC, which codes for a peptidoglycan hydrolase and is positioned immediately downstream of yggX, was also regulated by oxidative stress or ectopic expression of SoxS. Purified SoxS protein bound to the predicted yggX promoter region, between positions 223 and 163 upstream from the yggX translational start site. Within this region, a 20-bp sequence was found to be necessary for oxidative stress-mediated activation of yggX transcription. A yggX deletion strain was hypersensitive to the redox-cycling agent paraquat, and a plasmid expressing YggX complemented the sensitivity of the deletion strain. Under exposure to paraquat, the yggX deletion strain showed a deficiency in aconitase activity compared to the isogenic wild-type strain, while expression of YggX from a multicopy plasmid increased the aconitase levels above those of the wild-type strain. These results demonstrate the direct regulation of the yggX gene by the redox-sensing SoxRS system and provide further evidence for the involvement of yggX in protection of iron-sulfur proteins against oxidative damage.