Epidemiology of methicillin-resistant Staphylococcus aureus carrying the novel mecC gene in Denmark corroborates a zoonotic reservoir with transmission to humans.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of healthcare-associated (HA), community-associated (CA) and livestock-associated (LA) infections. Recently, the discovery of human and bovine MRSA isolates carrying a new mecA gene homologue, mecA(LGA251) (now designated mecC), has caused concern because they are not detected by conventional, confirmatory tests for MRSA. Very little is known about their frequency, epidemiology and possible transmission between livestock and humans. In this study, the epidemiology of the mecC isolates in Denmark was investigated by screening the national collections of MRSA cases (from 1988 onwards) and S. aureus bacteraemia cases (from 1958 onwards). Isolates carrying mecC were only recovered infrequently before 2003 (n = 2) but now seem to be increasing, with 110 cases in 2003-2011. Clinical data on mecC-carrying MRSA demonstrated that mecC-MRSA were primarily community-acquired (CA-MRSA) and affected persons typically living in rural areas, being older than other CA-MRSA patients. Among 22 cases in Region Zealand, four reported contact with cattle and sheep. Two of these persons lived on farms with livestock positive for mecC-carrying MRSA, sharing spa type (t843), MLVA (MT429) and PFGE pattern with the human isolates. These observations indicate that mecC-carrying MRSA can be exchanged between humans and ruminants.

[Nosocomial infections with penicillin-resistant Streptococcus pneumoniae. Four clusters with pneumococci serotype 9V]. / Nosokomielle infektioner med penicillinresistent Streptococcus pneumoniae. Fire ophobninger med pneumokokker serotype 9V.

INTRODUCTION: The objective was to alert Danish hospital physicians to the risk of nosocomial spread of penicillin-resistant Streptococcus pneumoniae (PRP). MATERIALS AND METHODS: The study was conducted in the County of Northern Jutland during the 3-year period 1996-1998. Data on isolates of PRP were retrieved retrospectively from a computerised laboratory information system, and additional information was obtained from patients' charts and notes by infection control nurses. RESULTS: Four incidents of likely nosocomial spread of PRP, serotype 9V, were identified in departments of medicine or pulmonary diseases. Clusters included two to four patients. The eleven patients were 53 to 92 years of age, and all but one had severe underlying pulmonary disease or a malignant disorder. During the same period, we found that among pneumococcal bacteraemias of definite origin 8.9% (95% confidence limits 5.9-12.9%) was nosocomial. CONCLUSION: The risk of nosocomial spread of pneumococci, including PRP, should be acknowledged. A policy of isolation should be implemented for patients with PRP; isolation precautions should also be considered for patients with a previous isolate of PRP if readmitted, as such patients may become chronic carriers.