Methicillin-resistant Staphylococcus aureus strains in New York City hospitals: inter-hospital spread of resistant strains of type 88

Abstract

Of 62 hospitals in New York City which sent strains for phage typing, 35 had methicillin-resistant isolates. A significant development was the presence of strains of the same phage type at several hospitals, indicating a possible inter-hospital spread of these strains. Among strains present at several hospitals, the largest group was of experimental phage type 88. Strains of type 88 were received from 23 hospitals, representing 56% of all methicillin-resistant strains received from New York City hospitals. Strains of type 88 were resistant to all antistaphylococcal antibiotics, with the exception of vancomycin, and represented a major source of nosocomial infections at 13 hospitals. As experimental phage 88 is not routinely used for typing in U.S. laboratories, the nationwide distribution of strains of type 88 is difficult to assess.

Antimicrobial resistance and gene transfer in Staphylococcus aureus

“…aureus have shown resistance to as many as 20 antimicrobial agents, including antiseptics and heavy-metal ions (Lyon & Skurray 1987). These new MRSA strains were responsible for outbreaks in many hospitals throughout the world (Schaefler et al 1984;Marple & Cooke 1988). Although these types of strains are generally susceptible to teicoplanin, rifampicin and vancomycin, they have the ability to survive challenges by almost all the antistaphylococcal agents available today.…”

Antimicrobial resistance patterns and plasmid profiles of <i> Staphylococcus Aureus</i> isolated from milk and meat

“…Most of these outbreaks were associated with individual wards or units, with neonatal, intensive care and burns units being particularly susceptible (1,9,10). In some instances however, the persistence and propensity for spread of these organisms posed a much more serious clinical problem involving numerous patients at several different hospitals (11,12). The organisms involved often possessed the capacity to counter almost all the antimicrobial agents available to the clinician for the treatment of severe staphylococcal infections (1).…”

Methicillin-resistant strains of Staphylococcus aureus resistant to quinolones

“…My laboratory routinely screens for the presence of antibiotic-resistant S. aureus strains among isolates received for bacteriophage typing from hospitals in New York City (4,5). Strains received between May 1987 and July 1988 were screened for susceptibility to the quinolones fleroxacin (Hoffmann-La Roche Inc., Nutley, N.J.) and ciprofloxacin (Miles Laboratories, Inc., West Haven, Conn.).…”

“…Among the strains isolated in hospitals, 56 belonged to international phage group III and 45 were experimental phage type 88. Strains of experimental phage type 88 were frequently found among methicillin-resistant S. aureus strains isolated in New York City (4).…”

“…A comparison of strains isolated at hospitals with those isolated at nursing homes (Table 1) showed a higher ratio of methicillin-susceptible strains among strains isolated at nursing homes. While strains of experimental phage type 88 isolated at hospitals are usually resistant to most antistaphylococcal antibiotics (4), the quinolone-resistant strain isolated at a nursing home was resistant only to penicillin. Given the frequent transfer of patients between nursing homes and hospitals, a further study of the relationship between the two groups could be of interest.…”