Preadmission screening of adults highlights previously unrecognized carriage of Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus in London: a cause for concern?
In the first study of its kind in the United Kingdom, we describe the colonization rate of ciprofloxacin-sensitive Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus (PVL-MRSA) in adult patients who were screened systematically at the time of hospital admission. We also describe the molecular characteristics of PVL-MRSA and antibiotic resistance phenotypes. A total of 55,760 specimens were screened for MRSA between April 2008 and December 2010. MRSA was identified in 1,998 specimens, and ciprofloxacin-susceptible (CSMRSA) isolates (385/1,998, or 19.3%) were subjected to PVL testing. Of these, 70 (18.1%) were identified as PVL-CSMRSA. During the study period, the MRSA colonization rate decreased from 4.6% to 2.8%. In contrast, the colonization rate of PVL-CSMRSA increased over time, rising from 0.075% in 2008 and 0.07% in 2009 to 0.22% in 2010. The mean patient age was 52 years (range, 18 to 90 years); over two-thirds were male. Seven different lineages of PVL-CSMRSA were identified. Over the 3 years, the Southwest Pacific clone (CC30) was dominant in our population. The CC5 clone was detected once in 2008 and not at all in 2009 but accounted for a third of all PVL-CSMRSA strains in 2010. This lineage was commonly associated with clindamycin resistance and, less frequently, tetracycline resistance. We conclude that there is hitherto unrecognized low-level carriage of PVL-CSMRSA among patients being admitted to hospitals in northwest London. We observed the emergence of the CC5 clone in 2010 with associated clindamycin and tetracycline resistance.
Department of Microbiology, Northwick Park Hospital, Harrow, Middlesex, UK.
Nicholas M
NM
Pantelides
Guduru
G
Gopal Rao
Andre
A
Charlett
Angela M
AM
Kearns
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001427:Bacterial Toxins / Q000235:genetics*; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D016000:Cluster Analysis; D003955:Diagnostic Tests, Routine; D005098:Exotoxins / Q000235:genetics*; D005260:Female; D006801:Humans; D015994:Incidence; D007956:Leukocidins / Q000235:genetics*; D008131:London / Q000453:epidemiology; D008297:Male; D008403:Mass Screening; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D058889:Molecular Typing; D015995:Prevalence; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D037521:Virulence Factors / Q000235:genetics*; D055815:Young Adult
D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D037521:Virulence Factors