Bacteriological profile of neonatal septicemia cases (for the year 1990-91).

M Mathur, H Shah, K Dixit, S Khambadkone, A Chakrapani, S Irani 
 Dept of Microbiology, Seth GS Medical College, Parel, Bombay, Maharashtra.

Correspondence Address:
M Mathur
Dept of Microbiology, Seth GS Medical College, Parel, Bombay, Maharashtra.

Full Text

::   Introduction

Neonatal septicemia constitutes an important cause of morbidity and mortality amongst neonates in India[1]. However, with presently available antimicrobial agents, neonatal septicemia may betreated successfully. Early diagnosis and proper management of neonatal septicemia can bring down the morbidity and mortality substantially. Hence, the present study was undertaken to study the bacteriological profile of neonatal septicemia cases and their antimicrobial sensitivity pattern for planning strategy for the management of these cases.

::   Methods

The study includes 1266 cases of clinically suspected neonatal septicemia, on the basis of antenatal high risk factors and signs and symptoms of sepsis, including maternal fever, prolonged rupture of membranes, foul smelling lochia, temperature instability, feeding difficulties, respiratory distress, jaundice, convulsions and autonomic disturbances, admitted in the 'Neonatal Intensive Care Unit of King Edward Memorial Hospital, during the period January 1990 to August 1991. Blood samples (2-3 ml) were collected with all aseptic precautions for culture and sensitivity studies.

Blood cultures were processed using the standard technique described by Cruickshank et al[2] and the antibiotic sensitivity was performed by Kirby -Bauer's disc diffusion method[3]. The aerobic isolates were studied in detail by Gram's staining, colony characteristics, biochemical properties and antibiotic sensitivity.

::   Result

Blood culture reports of these 1266 clinically suspected neonatal septicemia cases were reviewed and a culture positivity rate of 24.88% was observed. There was no growth in 75.12% of cases. [Table:1] shows the types of organisms isolated.

Gram negative bacilli constituted 87.1% of the total isolates. Klebsiella and Enterobacter species were the predominant pathogens amongst Gram negative organisms. Salmonella species was isolated from 2.4% of cases. Of Gram positive, Staphylococcus aureus was the predominant isolate (79%).

[Table:2] shows the antibiotic sensitivity of the isolates (in percentage) to the commonly used antibiotics.

::   Discussion

For the effective management of neonatal septicemia cases, study of the bacteriological profile with their antibiotic sensitivity pattern plays a significant role. In this study, blood culture positivity rate in neonatal septicemia cases was 24.88%, whereas in 75.12% of cases there was no growth. A high culture positivity rate (56%) has been reported by Sharma et a1[4]. However, a low blood culture positivity rate (32%) has been observed by Mondal et al[5], which is comparable with the present study.

A low blood culture isolation rate in this study might be due to several reasons, e.g. administration of antibiotics before blood collection either to the mother or to the baby or the possibility of infection with anaerobes, which cannot be ruled out. Moreover, negative blood cultures do not exclude sepsis. Cases with negative blood culture have been reported with fatal illness and post-mortem evidence of infection[6]. Chow et al[7] reported that 26% of all neonatal septicemia was caused by anaerobes.

In the present study, Gram negative organisms constituted the major group of isolates (87.1%) from neonatal septicemia cases. Amongst this group Klebsiella species has been found to be predominant pathogen (38.5%) and the rest included Enterobacter species, Pseudomonas, Escherichia coli, Proteus and Salmonella species. The predominance of Gram negative -corroborates with the findings of other workers[8],[9]. Another significant finding of the study is the isolation of Salmonella species in 2.4% of cases. An increasing incidence of Salmonella species has also been reported by Sharma et al4. A close watch needs to be kept on increasing incidence of this organism.

A comparatively low incidence (12.9%) of Gram positive organisms has been observed in our study, which correlates well with the findings (15%) of Sharma, et al4 Amongst the Gram positive organisms, Staphylococcus aureus was the predominant pathogen (79.0%).

The results of antibiotic sensitivity [Table:2] revealed that, minority of Gram negative isolates were sensitive to gentamicin, cefotaxime and ceftazidine; whereas majority of Gram positive isolates showed sensitivity to ampicillin, chloramphenicol, ceftazidine and cefotaxime. Salmonella isolates showed sensitivity to ceftazidine, cefotaxime and gentamicin.

The antimicrobial sensitivity pattern differs in different studies as well as at different times in the same hospital10-12. This is because of emergence of resistant strains as a result of indiscriminate use of antibiotics.

In view of the above facts the strategy of antibiotic usage in the hospital must be reviewed. Since a sizeable number of blood culture specimens were negative by aerobic culture, the possibility of infection by anaerobes must be entertained and therefore, anaerobic culture should be performed routinely in cases of neonatal septicemia.

::   Acknowledgment

We thank Dir (Mrs) PM Pai, the Dean Seth GS Medical College and King Edward Memorial Hospital for allowing us to publish the data.

References