Kakehashi H

Acinetobacter calcoaceticus biovar anitratus septicaemia in a neonatal intensive care unit: epidemiology and control

Nineteen neonates with septicaemia caused by Acinetobacter calcoaceticus biovar anitratus were treated in a neonatal intensive care unit between October, 1983 and March, 1986. The ages of the patients at the onset of septicaemia ranged from 4 to 22 days (mean 9.7 days). Their birth weights ranged from 1000 g to 3350 g (mean 1790 g) and were less than 2000 g in 14 patients. Antibiotics had been administered to 17 of the 19 neonates before the onset of septicaemia, and all mature infants had received prior antibiotic therapy, intubation or had suffered from a convulsion. Acinetobacter anitratus strains were isolated from pharyngeal swabs and/or faeces from 35 (79.5%) out of 44 infants of less than 2000 g. These strains were also isolated from the hands of staff members, and from equipment such as sinks and baths in the unit. It was likely that nosocomial infection via the hands of the staff occurred. Encouraging frequent hand-washing, strict antibiotic use, and cohorting of colonized infants resulted in a reduction of colonization and no further cases of septicaemia were reported.

Acquisition of nonmaternal Enterobacteriaceae by infants delivered in hospitals

To determine whether Escherichia coli strains that colonize the intestinal tract of newborn infants in hospitals are of maternal origin or come from the environment, plasmid profiles of E. coli strains isolated from the stools of infants were compared with those from the stools of their mothers. Twenty-nine mother-infant pairs were studied in three different hospitals. In only 4 of 29 pairs, plasmid profiles of E. coli or other Enterobacteriaceae were shared by infant and mother; vertical transmission seemed to be uncommon, unlike findings in previous reports. In one hospital, 8 of 10 infant fecal E. coli strains shared a single plasmid profile, strongly suggesting nosocomial acquisition. In another, 7 of 9 neonate strains also shared a unique profile, and additionally carried K1 capsular antigen, a known virulence factor. Two other infants from the latter nursery acquired a urinary tract infection with E. coli K1 carrying the same plasmid profile. This study indicates that nosocomial acquisition of hospital strains of E. coli by neonates may be common in some hospitals and that the clinical implications are potentially serious.

Mixed Invasive Aspergillosis and Candidiasis in a Fatal Case of Leukemia

A fatal case of leukemia complicated by mixed invasive aspergillosis and candidiasis is presented. Mixed fungal infections may occur in any immunocompromised patients. We should be careful to look for different morphologies of fungi in diagnostic examinations of lesions in these patients.

Antibiotic Susceptibility of Type b Haemophilus influenzae and Streptococcus pneumoniae, and Antibiotic Concentration in Cerebrospinal Fluid

Antibiotic susceptibilities of 38 type b Haemophilus influenzae and 28 Streptococcus pneumoniae strains isolated from cerebrospinal fluid, blood and other specimens between 1973 and 1988 were studied. Minimal inhibitory concentrations (MICs) of ampicillin against 10 β‐lactamase positive and 28 negative H. influenzae isolates were 32–64 and 0.25 μg/ml, respectively. The MIC of chloramphenicol against one of the β‐lactamase positive H. influenzae strains was 8 but MICs against the rest of the organisms were 0.5–1 μg/ml. MICs of cefotaxime, ceftriaxone and cefuroxime against all H. influenzae strains were 0.016, 0.008 and 0.5 μg/ml, respectively. No S. pneumoniae isolates were resistant to penicillin G and MICs of this drug were 0.016–0.032 μg/ml. MICs of cefotaxime, ceftriaxone and cefuroxime against all S. pneumoniae strains were 0.016–0.032, 0.016–0.032 and 0.032–0.063 μg/ml, respectively. MICs of chloramphenicol against 15, 4 and 9 of S. pneumoniae isolates were 2, 8 and 16 μg/ml, respectively. Antibiotic concentrations in the cerebrospinal fluid of patients with bacterial meningitis after intravenous administration of ampicillin (50–70 mg/kgx4/day), penicillin G (31–63 mg/kgx4/day), cefotaxime (50 mg/kgx4/day) and chloramphenicol (25 mg/kgx4/day) were 4.70±1.83 (n=11), 0.57±0.32 (n=7), 4.97±2.60 (n=9) and 8.52±3.54 μg/ml (n=3), respectively. The initial choice of antibiotics in older children with bacterial meningitis is a combination of ampicillin (75 mg/kgx4/day) and cefotaxime (50 mg/kgx4/day) to cover ampicillin‐resistant H. influenzae, S. pneumoniae, and Listeria monocytogenes in Japan. These antibiotics should be changed according to the causative organisms and their antibiotic susceptibilities.

Effects of aztreonam on fecal flora and on vitamin K metabolism.

The effects of aztreonam on fecal flora and on descarboxy prothrombin (PIVKA-II) in plasma and gamma-carboxyglutamic acid (Gla) in urine as an index of vitamin K metabolism were studied in seven children (age range, 2 months to 2 years) with urinary tract infections. Daily doses of aztreonam were 60 to 80 mg/kg. Stool specimens were obtained before the treatment, on days 3 to 5 of aztreonam use, and from 3 to 5 days after the cessation of treatment. The counts of enterobacteria decreased (P less than 0.01) and those of streptococci increased (P less than 0.05) during aztreonam treatment. The anaerobic organisms, especially bifidobacteria and bacteroides, showed no marked change. PIVKA-II and Gla were investigated before and during the treatment with aztreonam. PIVKA-II was not detected in seven patients before or during aztreonam use. There were no significant differences in the levels of Gla in urine before or during the treatment. Images

Septicemia in Immunocompromised Children and Their Intestinal Flora

Quantitative fecal bacteriology was performed in eight immunocompromised children with septicemia. The most marked change observed was suppression of the anaerobic bacteria. In seven patients, the predominant organisms were aerobic gram‐negative bacilli (GNB), and in six of these were the same as the causative organism of the septicemia. Thus, overgrowth of GNB in the gastrointestinal tract may result in invasion of the blood stream and septicemia in immunocompromised patients. To prevent this complication it is necessary to allow the normal intestinal flora to be maintained in these patients as long as possible. Antibiotics should therefore be prescribed with caution. For the same reason, use of immunosuppressive drugs should be kept to a minimum. Bacteriological examination of the stool and pharynx is useful in the management of immunocompromised patients.