Carbapenemase-producing Enterobacterales in hospital drains in Southern Ontario, Canada.

BACKGROUND: Hospital drains may be an important reservoir for carbapenemase-producing Enterobacterales (CPE). AIM: To determine prevalence of CPE in hospital drains exposed to inpatients with CPE, relatedness of drain and patient CPE, and risk factors for drain contamination. METHODS: Sink and shower drains in patient rooms and communal shower rooms exposed to 310 inpatients with CPE colonization/infection were cultured at 10 hospitals. Using short- and long-read whole-genome sequencing, inpatient and corresponding drain CPE were compared. Risk factors for drain contamination were assessed using multi-level modelling. FINDINGS: Of 1209 exposed patient room and communal shower room drains, 53 (4%) yielded 62 CPE isolates in seven (70%) hospitals. Of 49 CPE isolates in patient room drains, four (8%) were linked to prior room occupants. Linked drain/room occupant pairs included Citrobacter freundii ST18 isolates separated by eight single nucleotide variants (SNVs), related blaKPC-containing IncN3-type plasmids (different species), related blaKPC-3-containing IncN-type plasmids (different species), and related blaOXA-48-containing IncL/M-type plasmids (different species). In one hospital, drain isolates from eight rooms on two units were Enterobacter hormaechei separated by 0-6 SNVs. Shower drains were more likely to be CPE-contaminated than hand hygiene (odds ratio: 3.45; 95% confidence interval: 1.66-7.16) or patient-use (13.0; 4.29-39.1) sink drains. Hand hygiene sink drains were more likely to be CPE-contaminated than patient-use sink drains (3.75; 1.17-12.0). CONCLUSION: Drain contamination was uncommon but widely dispersed. Drain CPE unrelated to patient exposure suggests contamination by undetected colonized patients or retrograde (drain-to-drain) contamination. Drain types had different contamination risks.

[Agglutinins in the diagnosis of pertussis]. / Aglutinini u dijagnostici pertussisa.

The performed investigation showed that the results of agglutination test in diagnostics must be explained with reserve as a supplement to the clinical picture and the other laboratory findings. Titre must be followed at least for 20 days on many blood samples. The more reliable diagnosis according to agglutination test can be given only if we know in question is a nonimmunized child and titre is > or = 1:80. The negative and lower titres cannot exclude or confirm the disease.