Outbreaks of a Methicillin-Resistant Staphylococcus aureus Clone ST398-t011 in a Hungarian Equine Clinic: Emergence of Rifampicin and Chloramphenicol Resistance After Treatment with These Antibiotics.

Between July 2011 and May 2016, a total of 40 Staphylococcus aureus strains originating from 36 horses were confirmed as methicillin resistant (methicillin-resistant Staphylococcus aureus [MRSA]) in a university equine clinic. An additional 10 MRSA strains from 36 samples of clinic workers were obtained in October 2017. The first equine isolate represented the sequence type ST398, spa-type t011, and SCCmec IV. This isolate was resistant to a wide spectrum of antimicrobial agents. MRSA strains with the same genotype and with very similar resistance profiles were isolated on 21 more occasions from September 2013 to September 2014. A second outbreak occurred from May 2015 until May 2016. The first isolate in this second outbreak shared the same genotype, but was additionally resistant to chloramphenicol. The second isolate from August 2015 also showed resistance to rifampicin. The clone was isolated 18 times. Most of the human isolates shared the same genotype as the isolates from horses and their resistance patterns showed only slight differences. We can conclude that the MRSA-related cases at the Department and Clinic of Equine Medicine were all nosocomial infections caused by the same clonal lineage belonging to the clonal complex 398. The clonal complex 398 of equine origin is reported for the first time in Hungary. In addition, our observation of the emergence of new resistance to antimicrobial agents within the clonal lineage after treatment with antibiotics is of concern. Strict hygiene regulations have been introduced to lower the incidence of MRSA isolation and the related clinical disease.

Re-emergence of bovine haemorrhagic septicaemia in Hungary.

This paper reports an outbreak of haemorrhagic septicaemia caused by Pasteurella multocida B:2 in beef calves, a disease that has not been described in the Hungarian literature since 1943, and has not been reported to the World Organisation For Animal Health (OIE) since 1970. Acute haemorrhagic septicaemia was confirmed in beef calves on one small farm, and was suspected on two further nearby holdings with concomitant unexplained losses. The source of the infection could not be determined. Apart from a short duration of depression and loss of appetite, the affected calves developed characteristic distal limb oedema. Gross findings in two calves submitted for laboratory examinations included subcutaneous oedema and haemorrhages on serous membranes, and in one case severe pharyngeal lymph node enlargement was observed. Histological examinations revealed lesions characteristic of septicaemia. Moderate to large amounts of Pasteurella antigens were detected in all organs tested by immunohistochemistry. Two isolates of P. multocida (Pm240, Pm241) were cultured from these cases and examined in detail. These were identified as P. multocida ssp. multocida biovar 3. Both were toxA negative and belonged to serotype B:2. Multilocus sequence typing was used to assign these to a new sequence type (ST64) that is closely related to other haemorrhagic septicaemia causing strains of P. multocida regardless of the host.

Virulence type and tissue tropism of Staphylococcus strains originating from Hungarian rabbit farms.

Staphylococcosis has a major economic impact on rabbit farming worldwide. Previous studies described a highly virulent variant, which is disseminated across Europe. Such strains are reported to be capable of inducing uncontrollable outbreaks. The authors describe a survey conducted on 374 Staphylococcus strains isolated from rabbit farms, mostly from Hungary, between 2009 and 2014, from a variety of pathological processes. The virulence type of the strains was determined using a multiplex PCR system. 84.2% of the strains belonged to a previously rarely isolated atypical highly virulent type. Only 6.1% belonged to the typical highly virulent genotype. Even low virulent strains were present at a higher percentage (6.4%). For a small group of strains (3.2%) the detection of the femA gene failed, indicating that these strains probably do not belong to the Staphylococcus aureus species. The results reveal the possibility of the asymptomatic presence of highly virulent strains on rabbit farms. "Non-aureus" Staphylococcus sp. can also have a notable role in the etiology of rabbit staphylococcosis. An association with the lesions and the virulence type was demonstrated. Statistical analysis of data on organotropism showed a significant correlation between septicaemia and the highly virulent genotype.