Sensitivity Pattern of Micro Organisms of Septicemia in Neonatal Intensive Care Unit of a Tertiary Hospital, Bangladesh

Introduction: Neonatal septicemia is a clinical syndrome of systemic illness accompanied by bacteremia occurring in the first 28 days of life. Micro-organism causing neonatal septicemia varies from country to country and region to region and time to time. In many situations, conventional antibiotics are not sensitive to causative micro-organism. Our aim of the study is to identify causative organism and sensitivity pattern of micro-organism in Neonatal Intensive Care Unit, (NICU). Methods & Subject: Total 300 patients were enrolled in this study with clinically diagnosed septicemia with prior antibiotic treatment or not. This study was done in NICU of tertiary Hospital, Chittagong Medical College, Bangladesh during the period of January 2013 to July 2014. Blood culture was done in Bact/Alerd 3D system. Result: Out of 300 cases, 204 cases were culture negative and 96 cases (32%) were culture positive. Klebsiella is the commonest causative organism 52 (54.17%), followed by Pseudomonas 16 (16.67%), Acinetobacter 14 (14.58%), S. aureus 6 (6.25%), E. coli 6 (6.25%), E. coli with other Coli form 2 (2.08%). In this study, sensitivity of Klebsiella was mostly to Ciprofloxacin, Imipenem, Azithromycin, Co-trimoxazole, Piperaciline and Tazobactam. Sensitivity to Pseudomonas was mostly to Amikacin, Imipenem, Ciprofloxacin, Azithromycin and Cefoperazone with Sulbactum.. Sensitivity to Acinetobactor was mostly to Amikacin, Imipenem, Ciprofloxacin, Netilmicin. Sensitivity to S. aureus was mostly to Vancomycine, Amikacin, Imipenem, Meropenem. Sensitivity of E.coli was mostly to Amikacin, Ciprofloxacin, Ceftazidin. Most of the culture positive organisms not sensitive to conventional Ampicilin, Gentamycin. Conclusion: Microorganisms identified causing neonatal septicemias in our region are Klebsiella, Pseudomonas, Acinetobactor, E. coli and Enterobector. Antibiotic sensitive to identified microorganism were Amikacin, Ciprofloxacin, Levofloxacin, Imipenem, Meropenem, Vancomycin and Ceftazidim..Conventional Ampicillin sensitivity is not detected and Gentamicin sensitivity is also low.


Introduction
Neonatal septicemia is a clinical syndrome of systemic illness accompanied by bacteremia occurring in the first 28 days of life [1]. Micro-organisms causing neonatal septicemia are a bit different from region to region and also country to country depending upon various factors especially socioeconomic conditions and personal hygiene with environment. It may occur through transplacental infection or an ascending infection from mother's genitourinary tract and from the infected caregiver or nosocomial infections. The incidence of neonatal sepsis is 5 to 8 per 1000 birth, the highest rates occur in LBW, prenatal asphyxia, maternal infection and babies with congenital abnormalities [2]. In global perspective anaerobes and non type able H.influnzae. It is important to note that 20-30% of the survivors of neonatal sepsis may exhibit neurological squeal [2]. Sepsis related mortality is however largely preventable with rational antimicrobial therapy and aggressive supportive care. In most developing countries, gram negative bacteria remain the major source of infection and gram positive microorganisms have been implicated in developed countries, as the most common cause of neonatal sepsis.
While culture positive neonatal sepsis in the USA is 0.98% but in very low birth weight infants under prolonged intensive care the culture proven sepsis may be as high as 30% [3]. Neonatal sepsis is one of the commonest causes of prenatal mortality in the developing world. Mortality rate of early onset neonatal sepsis is 2 to 40% and late onset neonatal sepsis is 2 to 20%. Definitive diagnosis of neonatal sepsis is based on positive blood or cerebrospinal fluid (CSF) culture, both of which takes at least 24 to 48 hours and is often falsely negative. Due to irrational use of antibiotic, sensitivity pattern of microbes are also changed. In many situations, conventional antibiotics are not sensitive to causative micro-organisms & developed increased drug resistance making treatment extremely difficult. Thus, local epidemiology of neonatal sepsis should be constantly updated to detect changes in the pattern of infective pathogens and their susceptibility to various antibiotics.
Objectives of the study were to identify the causative organisms causing neonatal septicemia and to detect culture-sensitivity of the microorganisms.

Methodology
This is a hospital based prospective case series study which was performed in Neonatal intensive care unit (NICU), Chittagong Medical College Hospital, Bangladesh. Duration of this study was January 2013 to July 2014.and sample size was 300. Inclusion Criteria were Term and preterm babies irrespective of sex and weight, clinically diagnosed neonatal septicemia patient under antibiotic treatment and also without, prior antibiotic therapy included in this study. Exclusion Criteria were severe prenatal asphyxia, neonate with congenital anomalies, extremely low birth weight neonates and respiratory distress syndrome.
A baby with good primitive reflex, activity and breast fed in initial 48 hours of life, who then became sick were considered as neonatal sepsis. Characteristic findings of neonatal sepsis patients were respiratory distress in the form of tachypnoea and or severe chest in drawing, reluctant to feeding, abdominal distension, lethargy, hypothermia, Sclerema, Convulsion.
On the day of admission, from every case 3 ml of blood was collected from peripheral vein with aseptic condition and introduced into aerobic and anaerobic media. The blood culture specimens were sent and processed accordingly in Bact/ Alert 3D system in Microbiology laboratory. Departmental ethical committee gave consent to carry on this study and consent also taken from parents of this study cases.

Results
All the cases were grouped into three: Normal birth weight babies (NBW) (wt>2500g) was 30%, Low birth weight, LBW(1500-2500g) was 48% main bulk of patient in the study cases and very low birth weight babies, VLBW (<1500-1000g) was 22% ( Figure  1). In NBW group 57.8% were male and 42.2% were female. In LBW group 53% were male whereas 47% were female. In VLBW group 52.8% were male with 47.2% were female. Male female distribution was statistically insignificant. In NBW group early onset sepsis (EONS) was 42.2% but in late onset sepsis (LONS) was 57.8%. In LBW group EONS was 68.2% but late onset Sepsis 31.8%. In VLBW group, EONS was 86.1% but in LONS were 13.9 (Figure 3)*.