A novel rapid bioluminescence-based antimicrobial susceptibility testing method based on adenosine triphosphate consumption.

Introduction: Standard, phenotypic antimicrobial susceptibility testing (AST) methods require 16-20 h of incubation and are considered as the bottleneck in providing timely input for appropriate antimicrobial treatment. In this study, a novel adenosine triphosphate (ATP)-bioluminescence-based method which allows rapid AST within 3 h was described. Methods: Standard AST was performed for 56 Enterobacterales isolates using EUCAST disk diffusion (DD) methodology. For the bioluminescence-based rapid AST, suspensions of bacteria were prepared using Mueller-Hinton broth to obtain a turbidity of 0.5 McFarland. The suspensions were distributed into 96-well microtiter plates. ATP (20 mM) and fixed concentrations of different antibiotics were added. Following incubation at 37°C for 1 h, a luminescent reaction mixture, including the substrate luciferin and luciferase enzyme solutions, was added. The chemiluminescence was monitored using an imaging system. Light production demonstrated the presence of ATP, indicating that the isolate was susceptible to the antibiotic in the well. Absence or decrease of light intensity, compared with the growth control well, indicated the use of ATP as an indirect measure of bacterial growth, and therefore resistance to the antibiotic in the well. Results: The novel AST method was tested using a total of 348 test wells. Concordance was achieved for 290 (83.3%) of the tests, whereas 52 (14.9%) and 6 (1.7%) tests caused minor and major errors, respectively. Discussion: In this study, a bioluminescence-based rapid AST was developed based on the consumption of ATP by bacteria. Our method's uniqueness relies on determining ATP consumption by microorganisms in the presence or absence of an antibiotic. The novel AST method described in this study lays the groundwork for obtaining rapid results, which should be considered as a proof of concept. With further optimization studies, this novel method can provide higher accuracy and be introduced into clinical practice as a routine AST method.

Surveillance of respiratory viruses by aerosol screening in indoor air as an early warning system for epidemics.

The development of effective methods for the surveillance of seasonal respiratory viruses is required for the timely management of outbreaks. We aimed to survey Influenza-A, Influenza-B, RSV-A, Rhinovirus and SARS-CoV-2 surveillance in a tertiary hospital and a campus over 5 months. The effectiveness of air screening as an early warning system for respiratory viruses was evaluated in correlation with respiratory tract panel test results. The overall viral positivity was higher on the campus than in the hospital (55.0% vs. 38.0%). Influenza A was the most prevalent pathogen in both locations. There were two influenza peaks (42nd and 49th weeks) in the hospital air, and a delayed peak was detected on campus in the 1st-week of January. Panel tests indicated a high rate of Influenza A in late December. RSV-A-positivity was higher on the campus than the hospital (21.6% vs. 7.4%). Moreover, we detected two RSV-A peaks in the campus air (48th and 51st weeks) but only one peak in the hospital and panel tests (week 49). Although rhinovirus was the most common pathogen in panel tests, rhinovirus positivity was low in air samples. The air screening for Influenza-B and SARS-Cov-2 revealed comparable positivity rates with panel tests. Air screening can be integrated into surveillance programs to support infection control programs for potential epidemics of respiratory virus infections except for rhinoviruses.

Pseudomonasaeruginosa antimicrobial susceptibility profiles, resistance mechanisms and international clonal lineages: update from ESGARS-ESCMID/ISARPAE Group.

SCOPE: Pseudomonas aeruginosa, a ubiquitous opportunistic pathogen considered one of the paradigms of antimicrobial resistance, is among the main causes of hospital-acquired and chronic infections associated with significant morbidity and mortality. This growing threat results from the extraordinary capacity of P. aeruginosa to develop antimicrobial resistance through chromosomal mutations, the increasing prevalence of transferable resistance determinants (such as the carbapenemases and the extended-spectrum ß-lactamases), and the global expansion of epidemic lineages. The general objective of this initiative is to provide a comprehensive update of P. aeruginosa resistance mechanisms, especially for the extensively drug-resistant (XDR)/difficult-to-treat resistance (DTR) international high-risk epidemic lineages, and how the recently approved ß-lactams and ß-lactam/ß-lactamase inhibitor combinations may affect resistance mechanisms and the definition of susceptibility profiles. METHODS: To address this challenge, the European Study Group for Antimicrobial Resistance Surveillance (ESGARS) from the European Society of Clinical Microbiology and Infectious Diseases launched the 'Improving Surveillance of Antibiotic-Resistant Pseudomonas aeruginosa in Europe (ISARPAE)' initiative in 2022, supported by the Joint programming initiative on antimicrobial resistance network call and included a panel of over 40 researchers from 18 European Countries. Thus, a ESGARS-ISARPAE position paper was designed and the final version agreed after four rounds of revision and discussion by all panel members. QUESTIONS ADDRESSED IN THE POSITION PAPER: To provide an update on (a) the emerging resistance mechanisms to classical and novel anti-pseudomonal agents, with a particular focus on ß-lactams, (b) the susceptibility profiles associated with the most relevant ß-lactam resistance mechanisms, (c) the impact of the novel agents and resistance mechanisms on the definitions of resistance profiles, and (d) the globally expanding XDR/DTR high-risk lineages and their association with transferable resistance mechanisms. IMPLICATION: The evidence presented herein can be used for coordinated epidemiological surveillance and decision making at the European and global level.

Gardnerella vaginalis: Is it an Underestimated Cause of Urinary Symptoms in Males?

Objective: This study aimed to investigate the detection rate of Gardnerella vaginalis by multiplex PCR test in the genitourinary samples of male patients with suspected urethritis and related symptoms. Materials and Methods: A total of 144 male patients who presented to our department between February 2021 and October 2021, either with urinary symptoms or concerns following unprotected sex, were included in the study.A total of 128 (88.9%) first-void urine samples, 15 (10.4%) urethral swabs, and one (0.7%) semen sample were obtained. NeoPlex STI-14 Detection Multiplex PCR Kit (GeneMatrix Inc. Seongnam, South Korea) was used to investigate any of the following pathogens: Candida albicans, Chlamydia trachomatis, G. vaginalis, Mycoplasma genitalium, Mycoplasma hominis, Neisseria gonorrhoeae, Trichomonas vaginalis, Ureaplasma parvum, Ureaplasma urealyticum,herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), Treponema pallidum , Streptococcus agalactiae, and Haemophilus ducreyi. The patients with positive results for G. vaginalis were retrospectively analyzed. Results: The patients' median age was 37 (range: 21 to 71 years old). G. vaginalis was the most frequently detected microorganism (n=23; 15.9%). Other microorganisms found in order of frequency were U. urealyticum (n=19; 13.2%), U. parvum (n=15; 10.4%), C. trachomatis (n=11; 7.6%), M. genitalium (n=8; 5.6%), HSV-2 (n= 7; 4.9%), N. gonorrhoeae (n=6; 4.2), HSV-1 (n=2; 1.4%), M. hominis (n=1, 0.7%), and C. albicans (n=1, 0.7%). Fifteen patients (65%) were positive for one or two microbial agents together with G. vaginalis, while in eight patients (35%), G. vaginalis was the only isolated agent. Six of these eight patients and 14 of the remaining 15 were symptomatic. Conclusion: With the introduction of multiplex PCR tests, including those for G. vaginalis, we can expect a higher detection rate of these species of bacteria in male genitourinary samples, which could be the cause of unexplained urinary/urethral symptoms.