New reports of community-acquired MRSA
Today's New England Journal of Medicine reports 3 cases of community-acquired Staphylococcus aureus in children; two of the three cases were due to methicillin-resistant staph aureus, or MRSA (NEJM 353:1245-1251, 2005). The children were 15 months, 9 months, and 17 months of age; sadly, all cases were fatal.
Interestingly, the NEJM paper showed that all 3 isolates obtained from the patients were clonal by pulse-field gel electrophoresis (PFGE, in which restriction enzymes are used to cut the DNA, which is then run out on an agarose gel for analysis of band pattern) and multilocus sequence typing (MLST, which compares the sequences of several conserved housekeeping genes). The only difference by PFGE was the presence of the mec gene into the MRSA isolates. Therefore, this may be a commonly found population which has recently acquired methicillin resistance, and may be spreading through the population in Chicago.
Unfortunately, community-acquired MRSA (CA-MRSA) is looking like it's something that won't go away anytime soon. MRSA infections are still most commonly acquired nosocomially (that is, in a hospital setting), but several reports have shown they are occurring in the community at an increasing pace. Al-Shawwa et al. reported 6 cases of otitis media (ear infections) due to CA-MRSA. It's also become a player (pardon the pun) among athletes, with reports of infections in groups ranging from a high school wrestling team in Vermont to members of the St. Louis Rams football team. Don't expect to see this diminsh anytime soon; and be sure to wipe off that gym equipment before and after using it!
Interestingly, the NEJM paper showed that all 3 isolates obtained from the patients were clonal by pulse-field gel electrophoresis (PFGE, in which restriction enzymes are used to cut the DNA, which is then run out on an agarose gel for analysis of band pattern) and multilocus sequence typing (MLST, which compares the sequences of several conserved housekeeping genes). The only difference by PFGE was the presence of the mec gene into the MRSA isolates. Therefore, this may be a commonly found population which has recently acquired methicillin resistance, and may be spreading through the population in Chicago.
Unfortunately, community-acquired MRSA (CA-MRSA) is looking like it's something that won't go away anytime soon. MRSA infections are still most commonly acquired nosocomially (that is, in a hospital setting), but several reports have shown they are occurring in the community at an increasing pace. Al-Shawwa et al. reported 6 cases of otitis media (ear infections) due to CA-MRSA. It's also become a player (pardon the pun) among athletes, with reports of infections in groups ranging from a high school wrestling team in Vermont to members of the St. Louis Rams football team. Don't expect to see this diminsh anytime soon; and be sure to wipe off that gym equipment before and after using it!
