Genetic and phenotypic characterization of Haemophilus influenzae type b isolated from children with meningitis and their family members in Vietnam.
To investigate Haemophilus influenzae type b (Hib) infection in Vietnamese children under the age of 5 years, cerebrospinal fluid (CSF) samples from patients with meningitis were screened for Hib, and isolates were subjected to evaluation of susceptibility to 12 antibiotics, biotyping, and genotyping with pulsed-field gel electrophoresis (PFGE). The major biotype was type II (68.3%), followed by type I (22.8%). Among 79 Hib isolates, 45 (57%) were beta-lactamase-producing and ampicillin-resistant (44 and 1 isolates produced TEM-1- and ROB-1-type beta-lactamases, respectively), and 34 isolates (43%) were beta-lactamase-nonproducing and ampicillin-sensitive. No beta-lactamase-nonproducing and ampicillin-resistant isolates were found. The PFGE patterns of Hib isolates were highly divergent, but most could be classified into three clusters. We also investigated Hib colonization in household contacts of patients, and found that Hib isolates from the CSF of patients and from nasopharyngeal cavities of household contacts showed the same PFGE patterns. This observation suggested that household contacts of patients are a possible reservoir of Hib.
Phan
L T Huong
LT
Department of Bacteriology, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam. thanhhuong@hn.vnn.vn
Ngo
T Thi
TT
Dang
D Anh
DA
Vu
T T Huong
TT
Le
N Ming
NM
Tran
Q Canh
QC
Matsuoka
Mayumi
M
Kamachi
Kazunari
K
Yamazaki
Tsutomu
T
Arakawa
Yoshichika
Y
Sasaki
Tsuguo
T
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002555:Cerebrospinal Fluid / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D004197:Disease Reservoirs / Q000382:microbiology; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D019741:Haemophilus influenzae type b / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D008297:Male; D008583:Meningitis, Haemophilus / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D010641:Phenotype; D010802:Phylogeny; D016896:Treatment Outcome; D014744:Vietnam
D000900:Anti-Bacterial Agents