Multicenter clinical evaluation of a novel transcription-mediated amplification assay for SARS-CoV-2 molecular testing.

INTRODUCTION: The onset and spread of COVID-19 pandemic has forced clinical laboratories to rapidly expand testing capacity for SARS-CoV-2. This study evaluates the clinical performance of the TMA Procleix SARS-CoV-2 assay in comparison to the RT-PCR assay AllplexTM SARS-CoV-2 for the qualitative detection of SARS-CoV-2 RNA. METHODS: Between November 2020 and February 2021, 610 upper-respiratory specimens received for routine SARS-CoV-2 molecular testing were prospectively collected and selected at the Hospital Universitari Vall d'Hebron and the Hospital Universitari Bellvitge in Barcelona, Spain. All samples were processed in parallel with the TMA and the RT-PCR assays, and results were compared. Discrepancies were retested by an additional RT-PCR method and the clinical history of these patients was reviewed. RESULTS: Overall, the level of concordance between both assays was 92.0% (κ, 0.772). Most discordant results (36/38, 94.7%) corresponded to samples testing positive with the TMA assay and negative with the RT-PCR method. Of these discrepant cases, most (28/36, 77.8%) were finally classified as confirmed or probable SARS-CoV-2 cases according to the discrepant analysis. CONCLUSION: In conclusion, the TMA Procleix SARS-CoV-2 assay performed well for the qualitative detection of SARS-CoV-2 RNA in a multisite clinical setting. This novel TMA assay demonstrated a greater sensitivity in comparison to RT-PCR methods for the molecular detection of SARS-CoV-2. This higher sensitivity but also the qualitative feature of this detection of SARS-CoV-2 should be considered when making testing algorithm decisions.

Clinical and molecular epidemiology of community-acquired, healthcare-associated and nosocomial methicillin-resistant Staphylococus aureus in Spain.

A prospective cohort study including all new cases of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection in 64 Spanish hospitals during June 2003 was performed to investigate the epidemiology of MRSA in Spain. Only patients who yielded clinical MRSA-positive samples were included. Epidemiological and clinical data for a total of 370 cases were collected. Genotyping was performed using pulsed-field gel electrophoresis and multilocus sequence typing. Panton-Valentine leukocidin genes and the staphylococcal chromosomal cassette mec (SCCmec) were identified in representative isolates. MRSA was considered to be nosocomially acquired in 202 cases (55%), healthcare-associated (HCA) in 139 cases (38%), community-acquired (CA) in three cases, and of uncertain mode of acquisition in 26 (7%) cases. The pooled population-based rate was 2.31 cases/100,000 population/month, and the pooled nosocomial rate was 0.21 cases/1000 hospital stays (20.2% of S. aureus). Peripheral vascular disease, respiratory tract infections, catheter infections, bloodstream infections and crude mortality were more frequent among HCA cases, whereas neoplasia and urinary tract infections were more frequent among nosocomially acquired cases. Two clones related to the paediatric clone ST5-IV accounted for 71% of the isolates; EMRSA-16 has emerged in two different geographical areas. Only one isolate belonged to the formerly predominant Iberian clone. The three CA isolates were related to the USA300 clone. SCCmec type IV was the most frequent type in nosocomial and HCA isolates. The epidemiology of MRSA has changed in Spain; outpatients with previous healthcare contact represent a very important reservoir of MRSA, and community isolates are emerging.

In vitro activity of nadifloxacin against several Gram-positive bacteria and analysis of the possible evolution of resistance after 2 years of use in Germany.

Nadifloxacin has good activity against Propionibacterium acnes as well as against both meticillin-susceptible and -resistant Staphylococcus aureus (MSSA and MRSA, respectively) and Staphylococcus epidermidis. The aim of this study was to evaluate the activity of this fluoroquinolone against the abovementioned microorganisms, comparing isolates collected in 2007 in Germany, a country where nadifloxacin has been used for the last 2 years, with isolates collected from 2006-2007 in Spain where nadifloxacin has not been used. A collection of P. acnes from Hungary (strains collected during 2005-2006) and a collection of P. acnes from different countries in Europe (collected during 2002) were also included. The activity of nadifloxacin was compared with ciprofloxacin, erythromycin and clindamycin. Susceptibility testing of P. acnes was performed by agar dilution, whereas the susceptibility of the different staphylococci was determined by microdilution. Although the isolates were collected from three different countries (Spain, Hungary and Germany) where the use of quinolones can produce a different effect, no significant differences in the percentages of resistance to nadifloxacin were observed in P. acnes, MSSA, MRSA and S. epidermidis. Therefore, topical antibiotics such as nadifloxacin do not have an additional effect on resistance. Moreover, nadifloxacin presented much better activity than the comparator drugs used in this study against the studied microorganisms.

Outbreak of Legionnaires' disease in immunosuppressed patients at a cancer centre: usefulness of universal urine antigen testing and early levofloxacin therapy.

This report describes an outbreak of Legionnaires' disease in severely immunosuppressed patients hospitalised at a cancer centre. Universal urine antigen testing and early levofloxacin therapy appeared to lower case fatality rates in comparison with previous reports concerning this high-risk population. This diagnostic and therapeutic strategy should be considered when facing a nosocomial outbreak of Legionnaires' disease in immunosuppressed hosts.