Genomic and clinical case characterisation of Staphylococcus haemolyticus isolated from dogs and cats in the United States, including strains with high-level mupirocin tolerance.

BACKGROUND: Staphylococcus haemolyticus is a coagulase-negative commensal organism of both people and companion animals. It has pathogenic potential and when cultured is often meticillin- and multidrug-resistant. OBJECTIVES: To characterise the clinical features of dogs and cats with clinical skin disease that had positive S. haemolyticus skin cultures, and to employ whole-genome sequencing (WGS) to identify resistance genes and characterise the genetic relatedness of strains. MATERIALS AND METHODS: Isolates were identified by the institutional clinical microbiology laboratory by routine aerobic culture and susceptibility from seven veterinary hospitals across the United States. Then, WGS and analysis of each isolate were performed and clinical data collected via a retrospective clinician questionnaire. RESULTS: S. haemolyticus was identified from superficial (seven of 12) and deep (five of 12) cutaneous infections in our study. Most animals had received antimicrobials (10 of 12) and/or immunomodulatory drugs (nine of 12) within the six months before culture. WGS analysis revealed a variety of genetic lineages and a wide array of antimicrobial resistance genes. Meticillin resistance was identified in nine of 12 isolates and four of 12 isolates demonstrated mupirocin tolerance. CONCLUSIONS AND CLINICAL RELEVANCE: Staphylococcus haemolyticus may be an under-recognised pathogen in companion animals, and its demonstrated potential for multidrug-resistance, meticillin-resistance, and high-level mupirocin tolerance may create a therapeutic challenge. Further studies should evaluate the prior antimicrobial use and immunocompromised status as risk factors for infection with S. haemolyticus.

[Outpatient management of community acquired meticillin resistant Staphylococcus aureus (MRSA) in Belgium]. / Prise en charge ambulatoire du Staphylococcus aureus résistant à la méticilline (MRSA) d'origine communautaire en Belgique.

Meticillin resistance is observed among S.aureus strains since 1961 and is due to the synthesis by S.aureus of a modified penicillin binding proteins named PBP2a with decreased affinity to Meticillin. Meticillin-resistant S.aureus (MRSA) strains are resistant to all betalactam antibiotics except Ceftaroline. Three epidemiological type of MRSA are now described globally in Europe and certainly in Belgium. These different types of MRSA differ by their genetic composition, the presence of virulence factors, their transmissibility, their clinical picture and their sensitivity to ant ibiot ics. The first one are the hospi tal associated MRSA strains (HA-MRSA) that causes pneumonia, urinary tract infection or bacteremia mostly among old patients presenting multiple comorbidities. Multiresistance to antibiotics is frequent in HA-MRSA and treatment of HA-MRSA related infections usually necessitate hospitalization of the patient. The second type of MRSA is a livestock associated MRSA (LA-MRSA). At risk persons are person living in close contact to livestock as farmers and veterinarians). The third type of MRSA is the community associated MRSA (CA-MRSA) described among individuals with little or no exposure to healthcare facilities. CAMRSA has been recognized in Belgium since 2003. In more than 80 % of cases, it is responsible for skin and soft tissue infections such as abscesses, furuncles and purulent cellulitis in otherwise healthy individuals. A great proportion of the CA-MRSA strains carry the Panton- Valentine leukocidin gene, a severity factor of S.aureus infections. In Belgium up to 6 % of acute skin and soft tissue are due to CA-MRSA. Recurrent infections and transmission among household members are frequently described. Incision and drainage is the primary treatment of CA-MRSA associated abscesses. Antibiotic therapy is recommended only in patient with severe infect ions or with underlying comorbidities. CA-MRSA is usually susceptible to non betalactam antibiotics. Recommended antibiotics, if antibiogram shows the strain is suceptible to the drug, are clindamycin, doxycycl in and cotrimoxazole. Prevent ive educational messages on personal hygiene and appropriate wound care will complete the medical treatment. Decolonisation of the patient and the household members can be performed in case of recurrent lesions and/or dissemination among the family. Outbreak of CA-MRSA infections must be reported to the health inspector.

La résistance à la méticilline est décrite chez S.aureus dès 1961. Cette résistance confère une résistance à tous les antibiotiques de la famille des bêtalactames hormis la Ceftaroline. Trois origines épidémiologiques de staphylocoques résistants à la méticilline (MRSA) sont actuellement décrites globalement en Europe et certainement en Belgique. Ces différents types de MRSA sont distincts par leur composition génétique, la présence de facteurs de virulence, leur transmissibilité, le tableau clinique et leur sensibilité aux antibiotiques non bêtalactames. Il s'agit premièrement du HA-MRSA ou MRSA associé à l'hôpital qui y cause des pneumonies, infections urinaires, bactériémies surtout chez des sujets âgés et présentant des comorbidités. Ce type de MRSA est souvent résistant à de nombreux antibiotiques et son traitement nécessite l'administration d'antibiotiques à l'hôpital. Le deuxième type de MRSA, est un MRSA associé au bétail (LA-MRSA pour livestock associated MRSA). Les personnes à risque sont les personnes en contact avec les porcs et les veaux essentiellement (vétérinaires, éleveurs, personnels d'abattoir). Le troisième type de MRSA est le MRSA associé à la communauté (CAMRSA pour community associated MRSA). Observé en Belgique depuis 2003, il cause dans plus de 80 % des cas des infections des tissus mous telles qu'abcès, furoncles et cellulite suppurée. Le CA-MRSA est décrit surtout chez des individus jeunes en bonne santé. Une proportion importante de CA-MRSA sécrète la leucocidine de Panton Valentine, un facteur de gravité des infections causées par le S.aureus. En Belgique le CA-MRSA cause près de 6 % des infections aiguës des tissus mous. Des infections récurrentes ainsi que des infections multiples ausein de plusieurs membres d'un groupe ou famille sont décrites. Le traitement consiste en une incision/drainage des lésions abcédées. Des ant ibiot iques ne seront nécessaires qu'en présence de facteurs de gravité. Le CA MRSA est généralement sensible aux antibiotiques non bêtalactames actifs sur S.aureus. Les antibiotiques recommandés, si la sensibilité est démontrée à l'antibiogramme, sont le cotrimoxazole, la clindamycine et la doxycycline. Des messages éducationnels concernant l'hygiène personnelle et les soins de plaie compléteront le traitement. Une décolonisation du patient et éventuellement de son entourage peut être proposée en cas de lésions récurrentes. Les épidémies de CA-MRSA doivent être déclarées à l'inspecteur d'hygiène.

Bacterial contamination of mobile phones of healthcare workers at the University Teaching Hospital, Lusaka, Zambia.

BACKGROUND: Mobile telephones (henceforth 'phones') have become an essential part of everyday life in both healthcare and community settings. However, the widespread use of mobile phones in healthcare facilities is of concern because they can act as vehicles for transmitting pathogenic bacteria. This study aimed to investigate the bacterial contamination of mobile phones of healthcare workers (HCWs) at the University Teaching Hospital, Lusaka, Zambia. METHODS: This cross-sectional study, from May to July 2019, involved 117 HCWs. A self-administered questionnaire was used to gather sociodemographic and phone usage data. The mobile phones of HCWs were swabbed for culture and antimicrobial susceptibility testing. RESULTS: The overall prevalence of mobile phone contamination was 79%. The predominant isolates were coagulase-negative staphylococci (50%), Staphylococcus aureus (24.5%) and Bacillus spp. (14.3%). Other isolates were Escherichia coli, Acinetobacter spp., Pseudomonas spp., Klebsiella sp. and Proteus sp. Most isolates were susceptible to tetracycline, gentamicin and cotrimoxazole, while all Gram-positive organisms were resistant to penicillin. Meticillin resistance was detected in 25% and 48% of S. aureus and coagulase-negative staphylococci isolates, respectively. No significant association was found between mobile phone contamination and age group, gender, profession, mobile phone disinfection or work area. CONCLUSION: Mobile phones of HCWs carry potentially pathogenic bacteria and can be a source of healthcare-associated infections in healthcare settings. Hence, regulations regarding the use of mobile phones need to be developed, especially in critical areas, to reduce the dissemination of pathogenic bacteria from hands to phones and, potentially, to patients.

Circulation of a community healthcare-associated multiply-resistant meticillin-resistant Staphylococcus aureus lineage in South Yorkshire identified by whole genome sequencing.

BACKGROUND: A cluster of seven cases of skin and wound infections caused by a multiply resistant meticillin-resistant Staphylococcus aureus (MRSA) were detected in a small-town community in South Yorkshire. Initial microbiological investigations showed that all isolates belonged to a spa type observed rarely in England (t1476). AIM: To describe the epidemiology of t1476 MRSA in South Yorkshire. METHODS: Retrospective and prospective case ascertainment was promoted through communication with local microbiology laboratories. Public health investigation included a detailed review of clinical notes for a subset of nine cases. Genomic and phylogenetic analysis was undertaken on t1476 MRSA. FINDINGS: Thirty-two cases of t1476 MRSA infection or colonization were identified between December 2014 and February 2018. Cases were older adults (aged 50-98 years). Healthcare exposures for a subset of nine cases indicated frequent contact with a team of district nurses, with all but one case receiving treatment on the same day as another case prior to their own diagnosis. No cases were admitted to hospital at the time of specimen collection. Despite detailed investigations, no carriers were detected among district nursing staff. A long-term carrier/super-shedder was not found. Phylogenetic analysis indicated that t1476 MRSA cases from South Yorkshire were monophyletic and distant from both MRSA of the same lineage from elsewhere in the UK (N = 15) and from publicly available sequences from Tanzania. CONCLUSION: Genomic and epidemiological analyses indicate community-based transmission of a multiply resistant MRSA clone within South Yorkshire introduced around 2012-2013, prior to the detection of a spatial-temporal cluster associated with a distinct risk group. Surveillance data indicate continued circulation.

Desiccation tolerance is associated with Staphylococcus aureus hypertransmissibility, resistance and infection development in the operating room.

BACKGROUND: Desiccation tolerance increases Staphylococcus aureus survival and risk of transmission. A better understanding of factors driving intraoperative transmission of S. aureus pathogens may lead to innovative improvements in intraoperative infection control. AIMS: To determine whether desiccation tolerance is associated with intraoperative S. aureus transmission, and to examine typical transmission dynamics for desiccation-tolerant isolates in the operating room in order to provide the impetus for development of improved intraoperative infection control strategies. METHODS: S. aureus isolates (N=173) were collected from anaesthesia work area reservoirs in 274 operating room environments. Desiccation tolerance was assessed and the potential association with sequence type (ST) and clonal transmission was evaluated. Whole cell genome analysis and pulsed-field gel electrophoresis analysis were used to compare desiccation-tolerant isolates with causative organisms of infection. FINDINGS: S. aureus ST 5 isolates had greater desiccation tolerance than all other intraoperative STs [ST 5, N=34, median Day 2 colony-forming unit (cfu) survival 0.027% ± 0.029%; other STs, N=139, median Day 2 cfu survival 0.0091% ± 1.41%; corrected P=0.0001]. ST 5 was associated with increased risk of clonal transmission (relative risk 1.82, 95% confidence interval 1.23-2.71, P=0.003). ST 5 transmission was linked by whole cell genome analysis to postoperative infection. CONCLUSIONS: Increased desiccation tolerance is associated with intraoperative transmission of S. aureus ST 5 isolates that are linked to postoperative infection. Future work should determine whether attenuation of desiccation-tolerant, intraoperative ST 5 strains can impact the incidence of healthcare-associated infections.

A whole health economy approach to reducing MRSA bacteraemia incidence in diabetic foot ulcer patients.

INTRODUCTION: Ulceration of the foot is a common problem among diabetic patients. Infection is a major risk in diabetic foot ulcers (DFU) and many of these are caused by Staphylococcus aureus, in particular meticillin-resistant strains (MRSA). The control and management of MRSA remains a significant challenge and all healthcare organisations in England are required to meet Zero Tolerance Objectives for cases of MRSA bacteraemia (MRSAB). This paper describes a collaborative approach across the health economy to investigate factors contributing to the acquisition of MRSA and MRSAB among DFU patients and make improvements to care to reduce the risk of healthcare-associated infections. METHODS: A collaborative approach between acute and community healthcare providers and commissioners was used to conduct Root Cause Analysis and drive improvement to prevent MRSA transmission in DFU patients. RESULTS: Screening of all DFU patients was initiated after 6 MRSAB were found to be associated with in DFU. In total 15 patients with the same MRSA antibiogram were identified. Following the implementation of actions focused on isolation, wound management, screening and cleaning no further cases were identified. CONCLUSION: This outbreak has demonstrated the value of cross-sector collaboration in investigating HCAI in patients with DFU, improving patient care and reducing the risk of MRSA transmission in these vulnerable patents.

Wound infections caused by inducible meticillin-resistant Staphylococcus aureus strains.

Detection of meticillin resistance in Staphylococcus aureus isolates continues to be a challenge. Clinical specimens obtained from abscesses from two epidemiologically unrelated outpatients were positive for meticillin-resistant S. aureus (MRSA) by a commercial PCR assay, but colonies obtained by culture were susceptible to oxacillin by an automated testing method. The colonies were also negative using a penicillin-binding protein 2a (PBP2a) latex agglutination test. Because of the discrepancy between the genotypic and phenotypic results, both isolates were re-tested by PCR, disc diffusion, VITEK® 2 and MicroScan® and were plated on chromogenic agar. Both isolates also underwent cefoxitin induction for additional susceptibility testing studies. Following overnight induction with cefoxitin, both isolates demonstrated resistance to oxacillin and cefoxitin by the two automated methods and by disc diffusion, and were positive using PBP2a latex agglutination tests. Population analysis failed to identify heteroresistant subpopulations in uninduced isolates. Identifying the presence of MRSA by PCR directly in the specimens was critical for determining the appropriate course of antimicrobial therapy for the patients. Both infections resolved with non-ß-lactam therapy.

Elementos de interés clínico en la microbiología molecular de Staphylococcus aureus / Elements of clinical interest in the molecular microbiology of Staphylococcus aureus

El Staphylococcus aureus es uno de los microorganismos de mayor importancia en la asistencia médica, emergente en la comunidad y en el medio hospitalario. El objetivo de este trabajo es presentar una actualización sobre los elementos de interés clínico de la microbiología molecular del Staphylococcus aureus. Para confeccionar esta revisión se utilizaron las bases de datos de Scielo, HINARI, Pubmed-Medline y bibliografías disponibles sobre el tema y los descriptores empleados fueron: Staphylococcus aureus, resistencia a la meticilina, genes, epidemiología molecular, virulencia y la combinación entre ellos. Se revisaron los elementos que determinan sus factores de virulencia, la resistencia antimicrobiana, la versatilidad de estrategias patogénicas, la capacidad de sobrevivir en diferentes condiciones, la evolución y virulencia de los procesos que produce. Igualmente se abordó el diagnóstico de la resistencia, las técnicas de diagnóstico molecular, con sus utilidades, limitaciones, ventajas y desventajas y los estudios de estos temas en los últimos años en Cuba, pues circulan cepas de Staphylococcus aureus resistentes a la meticilina, pero no se conoce la situación real. Se recomienda la conveniencia y necesidad de organizar y armonizar estudios clínicos, epidemiológicos y microbiológicos, que puedan mostrar cuál es la situación actual de este microorganismo y sus infecciones, que aporten datos de su evolución molecular, para evaluar la tendencia de la situación encontrada, que permitan decisiones para el desarrollo de programas de vigilancia y control y revitalicen los medios y métodos de diagnóstico. Resulta importante el conocimiento actualizado del tema, la interpretación de nuevos resultados y el intercambio científico(AU)

Staphylococcus aureus is one of the most important microorganisms in medical care, emerging in the community and in the hospital environment. The objective of this work is to present an update on the elements of clinical interest of the molecular microbiology of Staphylococcus aureus. To make this review, the databases of Scielo, HINARI, Pubmed-Medline and bibliographies available on the subject were used and the descriptors used were: Staphylococcus aureus, methicillin resistance, genes, molecular epidemiology, virulence and the combination between them. We reviewed the elements that determine its virulence factors, antimicrobial resistance, the versatility of pathogenic strategies, the ability to survive in different conditions, the evolution and virulence of the processes it produces. Likewise, the diagnosis of resistance, molecular diagnostic techniques, with their utilities, limitations, advantages and disadvantages, and the studies of these subjects in recent years in Cuba were addressed, since methicillin-resistant strains of Staphylococcus aureus circulate, but not the real situation is known. It is recommended the convenience and need to organize and harmonize clinical, epidemiological and microbiological studies, which can show what is the current situation of this microorganism and its infections, that provide data of its molecular evolution, to evaluate the tendency of the situation found, that allow decisions for the development of surveillance and control programs and revitalize the means and methods of diagnosis. Current knowledge of the subject, interpretation of new results and scientific exchange is important(AU)