Change in antibiotic resistance of group B streptococcus: impact on intrapartum management.
OBJECTIVE
Intrapartum chemoprophylaxis has resulted in a significant reduction of group B Streptococcus neonatal infection. For penicillin-allergic patients, clindamycin or erythromycin is the recommended antibiotic. The purpose of this study was to establish any pattern of antibiotic resistance of group B streptococcal clinical isolates over the past 15 years.


METHODS
Group B streptococcal isolates obtained from the lower genital tract were tested for sensitivity to ampicillin, penicillin, clindamycin, and erythromycin. The sensitivity of 100 group B streptococcal isolates retrieved in the period 1997-1998 was compared with that of 85 group B streptococcal isolates from 1980-1993.


RESULTS
From 1980-1993 group B streptococcal isolates were available for testing for antibiotic resistance along with 100 isolates from a second study period 1997-1998. Of the 100 group B streptococcal isolates from 1997-1998, 18 were resistant to erythromycin, of which 5 were also resistant to clindamycin, as compared with 1 of the 85 isolates from 1980-1993 that was resistant to erythromycin (P <.001). All the isolates were sensitive to ampicillin and penicillin. All 18 resistant strains from 1997-1998 were found to be sensitive to cephalothin.


CONCLUSIONS
Over the past 18 years there has been increased in vitro resistance of group B streptococci to both clindamycin and erythromycin. If other studies confirm these findings, modifications to the current Centers for Disease Control and Prevention recommendations may be necessary.
Morales
W J
WJ
Florida Perinatal Associates, Department of Biology, University of South Florida, Tampa, 33613, USA.
Dickey
S S
SS
Bornick
P
P
Lim
D V
DV
D000667:Ampicillin / Q000494:pharmacology; D002981:Clindamycin / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D004917:Erythromycin / Q000494:pharmacology; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D010406:Penicillins / Q000494:pharmacology; D011247:Pregnancy; D012007:Rectum / Q000382:microbiology; D018805:Sepsis / Q000382:microbiology / Q000517:prevention & control; D013290:Streptococcal Infections / Q000517:prevention & control / Q000635:transmission; D013292:Streptococcus agalactiae / Q000187:drug effects* / Q000302:isolation & purification; D014621:Vagina / Q000382:microbiology
D010406:Penicillins; D002981:Clindamycin; D004917:Erythromycin; D000667:Ampicillin