An intensive care unit outbreak with multi-drug-resistant Pseudomonas aeruginosa - spotlight on sinks.

BACKGROUND: Pseudomonas aeruginosa and other Gram-negative bacteria have the ability to persist in moist environments in healthcare settings, but their spread from these areas can result in outbreaks of healthcare-associated infections. METHODS: This study reports the investigation and containment of a multi-drug-resistant P. aeruginosa outbreak in three intensive care units of a Swiss university hospital. In total, 255 patients and 276 environmental samples were screened for the multi-drug-resistant P. aeruginosa outbreak strain. The environmental sampling and molecular characterization of patient and environmental strains, and control strategies implemented, including waterless patient care, are described. RESULTS: Between March and November 2019, the outbreak affected 29 patients. Environmental sampling detected the outbreak strain in nine samples of sink siphons of three different intensive care units with a common water sewage system, and on one gastroscope. Three weeks after replacement of the sink siphons, the outbreak strain re-grew in siphon-derived samples and newly affected patients were identified. The outbreak ceased after removal of all sinks in the proximity of patients and in medication preparation areas, and minimization of tap water use. Multi-locus sequence typing indicated clonality (sequence type 316) in 28/29 patient isolates and all 10 environmental samples. CONCLUSIONS: Sink removal combined with the introduction of waterless patient care terminated the multi-drug-resistant P. aeruginosa outbreak. Sinks in intensive care units may pose a risk for point source outbreaks with P. aeruginosa and other bacteria persisting in moist environments.

Longitudinal increase in the detection rate of Mycobacterium chimaera in heater-cooler device-derived water samples.

BACKGROUND: Colonization with Mycobacterium chimaera and other non-tuberculous mycobacteria (NTM) has been reported for heater-cooler devices (HCDs) produced by several manufacturers. Up until now, exclusively LivaNova (London, UK) HCDs have been associated with M. chimaera infections after cardiac surgery. The vast majority of studies on HCD colonization were cross-sectional. AIM: We were interested in longitudinal dynamics of mycobacterial growth in HCD water samples and analysed data of a prospective mycobacterial surveillance of five LivaNova 3T HCDs. METHODS: Five LivaNova HCDs were subjected to prospective mycobacterial surveillance. For each HCD and the total of HCDs, results of mycobacterial detection were analyzed. Logistic regression was applied to model the association between growth of any NTM or M. chimaera and duration of HCD use. RESULTS: Non-tuberculous mycobacteria were isolated in 319 (48.0%, 21 water samples grew more than one mycobacterial species) of a total of 665 water samples. The most frequently detected species were M. chimaera (N = 247/319, 77.4%), Mycobacterium gordonae (46/319, 14.4%) and Mycobacterium paragordonae (34/319, 10.7%). Detection rates increased prospectively for any NTM (odds ratio (OR) per year in use: 1.60, 95% confidence interval (CI) 1.17-2.24, P<0.001) and for M. chimaera (OR per year in use: 1.67, 95% CI 1.11-2.57, P<0.01). CONCLUSION: Longer duration of HCD use was associated with higher detection rates for any NTM and M. chimaera, respectively.

Feline relapsing polychondritis: two cases and a review of the literature.

Only 11 reports of cats with relapsing polychondritis (RPC) were found in the literature. We describe two additional cases and provide a review of the literature. Predominantly young to middle aged cats are affected (range 1.5 to 14.5 years, median 3 years). There is no sex predilection for feline RPC. In all cats with feline RPC, the ears were affected. The findings in one of our cases and one case in the literature raise the question if other organs such as the joints, the eyes or the heart may be involved in feline RPC. The histological lesions observed in biopsy samples of the ears were similar in all cats. Glucocorticoids were not effective in the treatment of RPC. Dapsone appeared to result in some clinical improvement but side effects were observed in one of four cats. Some cats improved without treatment.

Pituitary gland changes in canine hypoadrenocorticism: a functional and immunocytochemical study.

Pituitary gland changes were evaluated immunocytochemically in three dogs with primary hypoadrenocorticism (HAC) and one dog with secondary HAC and related to the clinical, endocrinological and pathological findings. In primary HAC, the adrenocorticotrophic hormone (ACTH) immunoreactivity was increased in the pars distalis of the pituitary gland and all cortical layers of the adrenal gland were severely atrophied. This increase would be expected to reflect a high level of ACTH synthesis in the corticotrophs due to a lack of negative cortisol feed-back. In contrast, in the dog with secondary HAC the ACTH immunoreactivity was decreased in the pituitary gland, the basal plasma ACTH concentration was low and the zona fasciculata and reticularis were atrophied, but the zona glomerulosa was well preserved. These findings are consistent with a diminished synthesis of ACTH. Thus, pituitary gland changes differ in primary and secondary HAC and are consistent with the clinical, endocrinological and histopathological findings.

[Haemobartonella detection in cat blood smears]. / Haemobartonellen-Nachweis im Katzenblutausstrich.

Two useful staining methods for the diagnosis of haemobartonellosis on blood smears and distribution of Haemobartonellae on erythrocyte surfaces are shown.