Bacteriological Profile of Neonatal Sepsis in a Tertiary Level Hospital of Nepal

Address for correspondence: Ms. Rita Khanal Assistant Professor Department of Microbiology, Universal College of Medical Sciences Bhairahawa Nepal E-mail ritakhanal@gmail.com Telephone No. 009779867188819 1Rita Khanal, M.Sc. Medical Microbiology, Assistant Professor, Universal College of Medical Sciences, Bhairahawa Nepal, 2Sarita Manandhar, M.Sc. Medical Microbiology, Assistant Professor, National College Kathmandu, Nepal. 3Ganesh Prasad Acharya, M. Sc. Medical Lab Techonology, Department of Pathology, Paropkar Maternity and Women’s Hospital Kathmandu, Nepal. Abstract


Introduction
N eonatal Sepsis (sepsis neonatorum) is a clinical syndrome resul ng from the pathophysiologic eff ects of local or systemic infec on in the fi rst month of life.Neonatal sepsis remains as an important cause of morbidity and mortality among infants in developing countries accoun ng for 30-50% of total deaths each year 1 .The incidence of sepsis in neonatal period is 1-10 per 1000 live births with a mortality rate as high as 15-20% 2 .It is roughly three mes more in developing countries like Nepal.This high incidence is mainly due to poor antenatal care and lack of trained staff to conduct deliveries 3 .Classical neonatal infec on has been divided into Early or Late onset infec on, depending on the me of onset of infec on: early, before 48 hours and late, a er 48 hours 4 .
The common organisms responsible are Group B Streptococcus, Gram nega ve enteric organisms par cularly E.coli, other organisms such as Staphylococcus, Streptococcus, Listeria monocytogens, Haemophilus infl uenzae, Gram nega ve rods such as Klebsiella, Pseudomonas, Serra a and Proteus 5 .Since the spectrum of organisms that cause neonatal sepsis changes over me and varies from region to region and hospital to hospital even in the same city/country, it is necessary to conduct periodic surveillance to access the changing pa ern of organisms causing neonatal sepsis.For eff ec ve management of neonatal sep cemia with appropriate an bio cs, study of bacteriological profi le and their an bio c sensi vity pa ern plays a signifi cant role.In our country pre-exis ng data on both early and late onset sepsis has been shown great diversity in the changing pa erns of the organisms and their sensi vity pa erns.
Based on this considera on, a study was carried out to inves gate the causa ve bacterial organisms of Neonatal sepsis and to assess their an bio c suscep bility pa ern in the Neonatal unit of Paropakar Maternity and Women's Hospital, Thapathali, Kathmandu, Nepal.

Materials and Methods
A cross-sec onal prospec ve study was conducted at the Microbiological Laboratory of Paropakar Maternity and Women's Hospital from the period of December 2010 to April 2011.A total of 340 neonates (0 to 28 days of age) admi ed with suspected cases of early onset sepsis (0-2 days of age, n=229) and late onset sepsis (>3-28 days of age, n=71) were inves gated.One ml venous blood was drawn from the antecubital or femoral vein taking asep c precau ons by applying Povidone iodine and 70% alcohol at the site of vein puncture, and was inoculated into Brain Heart Infusion Broth (HiMedia, India) for culture.The specimens were transported within one hour to the Microbiology Laboratory.All posi ve blood cultures were iden fi ed by their characteris c appearance on their respec ve media, Gram staining reac on and biochemical reac ons.An microbial suscep bility tes ng was performed by disk diff usion method according to the Clinical and Laboratory Standards Ins tute (CLSI) 6,7 .

Results
Out of 340 samples 69 were blood culture posi ve.The prevalence rate of Neonatal sep cemia was found to be 20.3%.Among the total neonates 172 were males and 168 were female.Out of which growth posi ve cultures of male neonates were 36(52.17%)and female were 33(47.82%).There was no signifi cant diff erence between the sex of the baby and growth of the organism (p>0.05).Among the posi ve blood culture reports 50 of them were of EOS and 19 were LOS type (Figure 1).
The predominant organism in both Early and Late onset sepsis was S.epidermidis (Table 2).There was no signifi cant diff erence between the organisms isolated and the onset of Neonatal sepsis (p>0.05).
The an bio c sensi vity tes ng was performed for 69 isolates.The organisms isolated showed diff erent sensi vity to the drugs used.Amikacin showed the highest sensi vity to all types of organisms isolated from the posi ve blood culture.Vancomycin sensi vity was highest for Gram posi ve organism and Gentamicin was most eff ec ve for Gram nega ve organisms isolated.Ampicillin was the resistant drug (Table 3).

Discussion
The spectrum of organisms that cause neonatal sepsis changes over me and varies from region to region 8 .These organisms have also developed increasing mul -drug resistance over the last two decades 9 .Therefore knowledge of the pa ern of bacterial isolates and their an microbial suscep bility pa ern is useful for prompt treatment of pa ents.Among 340 samples, 69 (20.3%) showed posi ve blood culture.The growth posi vity rate diff ers depending on the sample size and the me period of the study.Similar previous studies from home and abroad have reported the growth posi vity varying from 5% to 70% 10,11,12 .In our study growth posi vity rate was high among male neonates (52.17%) than female neonates (47.82%) (p>0.05).Similar fi nding were reported from various places 12,13,14 .Male preponderance this could be because of the priority given to male babies for medical care in our society.
Gram Posi ve Cocci (88.40%) were predominant isolate followed by Gram nega ve bacilli (11.60%).In various other hospitals the organisms isolated diff er from me to me.Similar fi ndings were reported in Gaza hospital 18 .Coagulase-nega ve Staphylococcus was predominant in Taipei hospital 19 .In Johannesburg hospital Gram nega ve bacilli were isolated more in EOS and Coagulase nega ve Staphylococcus in LOS 20 .In New Delhi ter ary Hospital, Klebsiella (33.8%),Enterobacter (7.5%), Alcaligenes faecalis (4.9%), and Escherichia coli (4.6%) being the common microbes.Staphylococcus aureus (24.4%), followed by Coagulasenega ve staphylococci (7.9%), were the major Gramposi ve isolates 21 .Comparing the neonatal blood culture results in diff erent studies, the common isolates may vary from place to place and ins tu on to ins tu on.
In early onset sepsis, gram posi ve and gram nega ve bacteria accounted for 86% and 14% respec vely (p>0.05).In late onset sepsis, only one isolate was Gram nega ve and remaining were gram posi ve bacteria.Comparable fi ndings have been reported in other studies 22,23,24 .
In the present study the predominant organism from EOS and LOS are Coagulase nega ve staphylococci (CoNS).Studies from diff erent countries report CoNS as the predominant organisms in LOS and among infants with indwelling central venous catheters from intensive care units 25 .Recovery of CoNS from blood of sep cemic neonates needs to be reviewed with cau on since most of them are regarded as contaminants.CoNS especially Staphylococcus epidermidis are the major normal fl ora of the skin and they can contaminate blood at the venipuncture site during collec on of blood 26,27 .
Classical ini al (empiric) treatment of neonatal sepsis consists of a combina on of penicillin (Benzylpenicillin, Ampicillin or Cloxacillin) and Aminoglycoside (most commonly Gentamicin) 28,29 .In this study, Amikacin was found most effi cient for all the isolates.Vancomycin sensi vity was highest for Gram posi ve organism and Gentamicin was most eff ec ve for Gram nega ve organisms isolated.Gram-nega ve bacteria showed high-level resistance to ampicillin.This observa on is comparable to that of other researchers 7,30,31 .
An microbial sensi vity pa erns diff er in studies and at diff erent mes.This is due to emergence of resistant strains as a result of indiscriminate use of an bio c 16,31 .The high resistance rates in this study may be associated with frequent use of an bio cs for both prophylaxis and treatments of neonates in hospital.Mul ple drug resistance (resistance to two or more drugs) was observed.In gram nega ve group, MDR was 8 (100%) and Gram posi ve were 40 (65.57%).Among the Gram posi ves, MDR was observed among Staphylococcus aureus, Coagulase nega ve staphylococci and while among the Gram nega ves, MDR was observed in Klebsiella spp and Escherichia coli.Emerging mul ple drug resistance has also reported in other parts of the world 32,33 .

Conclusion
The study showed the predominance of Gram posi ve cocci par cularly coagulase nega ve Staphylococci as the causa ve agent of Neonatal sepsis.This may be a probable indica on of nosocomial infec on.The an microbial suscep bility pa ern showed high occurrence of MDR strains.This suggests that empirical an bio c therapy should be reviewed based on con nuous an bio c resistance surveillance.

Fig 1 :
Fig 1: Pie chart showing the distribu on of neonatal sep cemia based on the onset of disease

Table 1 :
Bacteriological profi le of the posi ve blood culture

Table 2 :
Bacteriological Profi le of the EOS and LOS.

Table 3 :
An bio c Sensi vity Pa ern of the Isolated Organisms

Table 4 :
Mul Drug Resistance Rate