Impact of ampicillin and cefuroxime on bacterial colonization and infection in patients on a neonatal intensive care unit.

The impact of ampicillin and cefuroxime on the bacterial flora of neonates was examined in a neonatal intensive care unit (NICU). For the first period of study (January-September 1989), ampicillin plus gentamicin were used as empirical therapy of infection. During this time, 92.6% of all Gram-negative bacilli (GNB) were resistant to ampicillin and 56.6% to cefuroxime. These percentages decreased significantly (P < 0.05) to 60.0% and 16.2% respectively, over the next period of study (October 1989-October 1990) when cefuroxime+gentamicin were used. A decrease in the number of cases of GNB from bacteraemia and meningitis was also significant (from 21.2% to 11.2%), and this correlated with a decline in the occurrence of Klebsiella pneumoniae. However, the number of enterococcal isolates and cases of enterococcal bacteraemia increased. These observations underline the important effect of ampicillin and cefuroxime in modulating the bacterial flora and its antibiotic resistance in patients on a NICU.

[Duration of the Neisseria meningitidis serogroup B serotype 2 carrier state]. / Trajanje kliconostva Neisseria meningitidis serogrupe B serotipa 2.

Of 168 examined secondary school children from Zagreb, Neisseria meningitidis, serogroup B, serotype 2 was isolated from the pharynx smear taken from 14 healthy carriers, aged 15-18. Carriership was observed during the period of 19 months. During that period the pharynx smear was taken four times so that in total there were five samples from each examinee, with the purpose of finding Neisseria. Neisseria meningitidis serogroup B, serotype 2 was isolated and identified by using the standard microbiological methods. Serogroup and serotype were identified by the slide agglutination method, and were used group and type specific antisera. Of 14 identified carriers two persons had continuous duration of carriership of N. meningitidis, serogroup B, serotype 2 during the period of nineteen months. In 6 persons over the period of 9 months, in all five samples of pharynx smear the same meningococcus was identified. This epidemiological study has determined the longest duration of carriership of Neisseria meningitidis serogroup B, serotype 2 described so far in the literature. The role of carriership in the occurrence of the meningococcal disease has not been fully explained.

Endemicity of cholera in Surabaya, Indonesia.

As the seventh pandemic of cholera is caused by V. cholerae biotype El Tor, the former criteria for endemicity of cholera need to be reconsidered as regards their applicability in areas that are infected with cholera. As the mortality rate of cholera nowadays can be reduced to a very low level due to modern methods of treatment, it is suggested that the infection rates of cholera should be taken into consideration as criteria of cholera endemicity, i.e. 1. Five years persistence of cholera cases in a given area. 2. Five percent infection rate among family contacts of cholera cases. 3. Minimum infection rate of 1% in a vicinity where cholera cases occur. It was also found that in such an endemic area it is very difficult to eliminate V. cholerae infection from a locality, even when all family contacts are treated with the full dose of tetracycline.

A controlled field trial of plain and aluminium hydroxide-adsorbed cholera vaccines in Surabaya, Indonesia, during 1973--75.

A controlled field trial comparing the effectiveness of a plain cholera vaccine with that of a vaccine adsorbed to aluminium hydroxide was carried out in a cholera-endemic area of Indonesia during 1973-75. Tetanus toxoid adsorbed to aluminium phosphate was used as the control. In vaccinees aged 1-4 years, the adsorbed cholera vaccine provided about 88% protection for 6 months following vaccination and still provided about 50% protection between 11 and 14 months after vaccination. In the same age group, the plain vaccine provided only 53% protection during the first 6 months and no appreciable protection beyond that period. In those aged 5 years and over, both vaccines provided 50-60% protection throughout the period of observation (14 months). Neither vaccine caused any serious side effects.

Antibody response in the intestinal secretions of volunteers immunized with various cholera vaccines.

The efficacy of various cholera vaccines in eliciting an intestinal antibody response was assessed in human volunteers who received oral live, oral killed, or parenteral cholera vaccines, or placebo. The intestinal immune response in terms of antibacterial and antitoxin antibodies was determined 2 and 4 weeks after immunization. By means of the mouse peritoneum opsonization assay and the infant mouse protection test, antibacterial activity could be detected in the intestinal secretions of volunteers who had been immunized either orally or by the parenteral route. Significant protective activity and duration of immunity were observed with the oral killed vaccine. The bacteriological data indicated the absence of significant intestinal colonization of the live attenuated strain after oral administration, and probably explains the observed lack of effectiveness of the oral vaccine compared with that of the killed vaccine. The predominant immunoglobulin class of intestinal antibody was found to be IgA. None of the vaccines used in the study elicited significant antitoxin activity in the intestinal secretions, as determined by the skin permeability neutralization test.