[Clinical effects of piperacillin and tazobactam/piperacillin on Haemophilus influenzae lower respiratory tract infection in pediatric patients].
OBJECTIVE
The prevalence of beta-lactamase-nonproducing ampicillin-resistant (BLNAR) Haemophilus influenzae (H. influenzae) has been increasing in recent years. Piperacillin (PIPC) is one of a few beta-lactams possessing good activity against BLNAR H. influenzae. We studied clinical efficacy of piperacillin and its beta-lactamase inhibitor, tazobactam/piperacillin (TAZ/PIPC) in children with lower respiratory tract infection caused by H. influenzae including resistance strains.


METHODS
Subjects were 20 children with lower respiratory tract infection caused by H. influenzae treated with PIPC 100mg/kg/day (7 cases) or TAZ/PIPC 125mg/kg/day (13 cases). We selected cases from which resistant H. influenzae strains might be detected. Patients received prior antimicrobial therapy within two weeks before admission, or with underlying diseases. We examined patient profiles, clinical efficacy, susceptibilities for 6 beta-lactam antibiotics [PIPC, TAZ/PIPC, ampicillin (ABPC), cefotaxime (CTX), ceftriaxone (CTRX), and meropenem (MEPM)] and analyzed 6 genotype patterns of beta-lactam resistant genes by PCR.


RESULTS
Efficacy was 7/7 in patients in PIPC group and 12/13 in patients in TAZ/PIPC group. Diminished efficacy was seen in only one case complicated with severe RSV infection. The susceptibility of all strains but one beta-lactamase producing, ABPC resistant (BLP) strain to PIPC and of all to TAZ/ PIPC was below 0.25 microg/mL. The genotype of the 15 strains isolated from the sputum on administration was as follows; beta-lactamase nonproducing, ABPC-susceptible (gBLNAS) strains were 4, gBLP strain was 1, beta-lactamase nonproducing, and ABPC-resistant (gLow-BLNAR) strains were 2, beta-lactamase nonproducing, ABPC resistant (gBLNAR) strains were 8.


CONCLUSIONS
PIPC and TAZ/PIPC were useful against lower respiratory tract infection caused by H. influenzae including BLNAR in children.
Sudo
Fusayo
F
Chiba Children's Hospital, Division of Infectious Diseases.
Ishiwada
Naruhiko
N
Hoshino
Tadashi
T
Fukasawa
Chie
C
Inami
Yukiko
Y
Hishiki
Haruka
H
Takeda
Nobue
N
Kurosaki
Tomomichi
T
Kohno
Yoichi
Y
D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D006192:Haemophilus Infections / Q000188:drug therapy*; D006193:Haemophilus influenzae; D006801:Humans; D007223:Infant; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000627:therapeutic use; D010878:Piperacillin / Q000627:therapeutic use*; D000077725:Piperacillin, Tazobactam Drug Combination; D012141:Respiratory Tract Infections / Q000188:drug therapy*
D000900:Anti-Bacterial Agents; D000077725:Piperacillin, Tazobactam Drug Combination; D010397:Penicillanic Acid; D010878:Piperacillin