Improved detection of non-tuberculous mycobacteria in hospital water samples.

Non-tuberculous mycobacteria (NTM) are opportunistic pathogens commonly colonizing hospital water systems, and may be responsible for healthcare-associated infections (HAI). Investigation of HAI and outbreaks caused by NTM necessitates water analyses. However, NTM are slow-growing bacteria within the mesophilic community present in water, and are difficult to detect. Prior to culture on specific media, their recovery usually requires decontamination and concentration steps. We assessed the effectiveness of filtration as regards the recovery of 7 NTM species in hospital water samples. We also compared the use of cetylpyridinium chloride (CPC) at different concentrations and Sodium Hydroxide (NaOH) 4% in decontamination of water samples with mesophilic bacteria. Our laboratory protocol showed that membrane filtration was suitable for concentration and recovery of NTM from water. Sample decontamination with CPC was more NTM-preservative than NaOH. A combination of CPC at 0.005% and filtration allowed detection of NTM at low concentrations, ranging from 3 to 98 CFU/100mL according to the NTM species.

Improving tuberculosis management in prisons: Impact of a rapid molecular point-of-care test.

OBJECTIVE: To improve tuberculosis (TB) diagnosis in prison, we evaluate the value of the XpertⓇMTB/RIF Ultra assay (Xpert) as point-of-care (POC) in a French prison hospital. METHODS: We first validated Xpert use on raw sputum at the referent laboratory. Secondly, trained physicians at the prison hospital performed Xpert tests for each patient presenting TB symptoms. The results were compared with Xpert, microscopic examination, culture and drug susceptibility testing on the corresponding decontaminated specimens. RESULTS: 76 inmates were included in 15 months and 21 were diagnosed with TB. The overall sensitivity, specificity, positive and negative predictive values of Xpert were respectively: 92.3%, 100%, 100% and 98.7% on raw sputum. The efficiency of the molecular POC was confirmed by a concordance of 97% between Xpert findings from the prison hospital and culture results. Delay of microbiological diagnosis was reduced by about 18 days for 13 inmates with smear-negative sputum that avoid the mobilization of major means (escort, transport) to perform fibroscopic samples. Repeated Xpert negative results helped to speed the lifting of inmate isolation. CONCLUSIONS: The implementation of Xpert in prison could optimize the management of incarcerated patients and thus limit the spread of TB among inmates, carers and other staff.

An outbreak of Pseudomonas aeruginosa urinary tract infections following outpatient flexible cystoscopy.

The investigation of an outbreak of Pseudomonas aeruginosa urinary tract infections after ambulatory cystoscopies identified a damaged cystoscope contaminated by P aeruginosa and acting as a relay object. This outbreak urges us not to trivialize urinary tract infections occurring after an elective cystoscopy. Patients should be advised to signal the occurrence of urologic symptoms after urologic exploration.