Sepsis is a life-threatening condition that arises when the body’s response to infection causes injury to its own tissues and organs^[1]. According to the data from National Neonatal Perinatal Database 2002-03, incidence of neonatal sepsis was 30 per 1000 live births. Sepsis is one of the leading causes of neonatal mortality accounting for 18.6% neonatal deaths. Antibiotics should be re-viewed once the results of the cultures and sensitivity are available.

Neonatal sepsis is a clinical syndrome consisting of nonspecific symptoms and signs of infection accompanied by bacteraemia in the first 28 days of life ^[2,3]. Septicaemia has been classified as early onset septicaemia (EOS) and Late Onset Septicaemia (LOS). The microorganisms most common associated with EOS include Group B Streptococcus (GBS), Escherichia coli, coagulase negative Staphylococcus species (CONS), Haemophilus influenza and Listeria monocytogenes and LOS is caused by CONS, S. aureus, E. coli, Klebsiella spp., Pseudomonas spp., Enterobacter. It contributes to nearly 30 % of neonatal deaths in developing countries^[4].

Risk factors of EOS are^{[5, 6]} Low birth weight (< 2500gms) or preterm baby, Febrile illness in the mother within 2 weeks prior to delivery, Foul smelling and/or meconium stained liquor amnii, Prolonged rupture of membrane (>24 hours), Prolonged and difficult delivery with instrumentation. Risk factors for development of LOS include: ^[7,8] Poor hygiene, Low birth weight (LBW), Poor cord care, Prematurity, Bottle feeding, Superficial infection (pyoderma, umbilical sepsis), Pre lacteal feeding.

The organisms most frequently involved in early-onset Neonatal sepsis of term and preterm infants together are GBS and Escherichia coli, which account for approximately 70% of infections combined. Current epidemiological trends are showing a decrease in the frequency of early-onset GBS disease related directly to prenatal screening and treatment with intrapartum antibiotics (IPA)^[9-11]. The use of intrapartum maternal prophylaxis for GBS has reduced the incidence of early-onset GBS disease by at least 80%; however, GBS remains one of the leading causes of EOS^[12]. Complications involves Septic Shock, Acute Respiratory Distress Syndrome (ARDS).

Diagnosis and management of sepsis are a great challenge facing neonatologists in NICUs. Clinical diagnosis of presentation is difficult due to nonspecific signs and symptoms. In addition, laboratory diagnosis is time consuming. This matter necessitates the initiation of empirical antibiotic therapy till the suspected sepsis is ruled out. Many studies suggest that resistance is directly associated with the selection of inappropriate antimicrobials, which leads to increased patients’ mortality^[13].

Antimicrobials used to treat sepsis in neonates usually include beta-lactams such as ampicillin, oxacillin, and cefotaxime; extended-spectrum beta-lactams such as piperacillin-tazobactam; and the carbapenem. Meropenem. These are bactericidal agents that inhibit the synthesis of the peptidoglycan layer of the bacterialcell wall^[14].

Objectives

• To identify most common organism causing sepsis

• To analyse most sensitive antibiotics against specific microorganism

• To compare the different organism with different antibiotic sensitivities

• To analyse the data and draw the conclusion

Materials

The study is based on a prospective analysis of all cases admitted to the neonatal intensive care unit (NICU) of Govt. Head Quarters Hospital Tiruppur, Tamil Nadu. The study was carried out from February to August 2019.

Inclusion Criteria

• Sepsis cases in the department of sick neonatal care unit (SNCU)

• Including both genders

• Patients admitted in the secondary care hospital

Exclusion Criteria

• Complicated cases are avoided

• Those patients who do not consent are excluded

• Patients above 28days are excluded

Materials

The study was conducted in Govt. Headquarters hospital, Tiruppur, a 600 bedded multispecialty tertiary care hospital. The study procedure was conducted in the microbiology lab by taking the blood samples. The positive blood samples were taken for identifying whether the bacteria is gram positive or negative by gram staining method. By using different biochemical tests, the organisms were identified and antibiogram was done using appropriate antibiotics by Kirby-Bauer disc diffusion method.

Total 50 patients with positive blood culture were studied during the study period. Among the culture positive cases, Gram-negative organisms were isolated in 30 cases(60%), Gram-positive in 20 cases(40%) Fig 1, Table 1-6

Antibiotic sensitivity growth of microoganisms and resistant produced by microorganisms

Figure 1: Total of Gram Positive And Gram Negative Cases

Table 1:

Table 2: Distribution of Risk Factors in Early Onset Sepsis And Late Onset Sepsis (50cases)

Table 3: Number of Antibiotic Sensitivity And Resistant Cases

Table 4: Sensitivity Level of Staphylococcus Species

Table 5: Sensitivity Level of Klebsiella Pneumoniae

Discussion

Sepsis in neonates refers to generalised bacterial infection documented by positive blood culture in the early weeks of life and is one of the four leading causes of neonatal mortality and morbidity in India. Neonatal sepsis continues to be a major problem for neonates in neonatal intensive care unit around the world.

Our study has been conducted and carried out in SNCU, Govt. Head Quarters Hospital Tiruppur for a 6 month time period. This study was conducted for identifying most common neonatal sepsis causing microorganisms and its antibiotic sensitivity. A similar study was conducted by Samuel EK Acquah et.al.^[15] in Tamale Teaching Hospital also focused on the susceptibility of bacterial etiological agents and commonly used antimicrobial agents in neonatal sepsis.

The present study is an attempt to closely monitor the microorganisms causing neonatal sepsis and to identify the most sensitive antibiotic. A total number of 50 patients were analysed. Based on the type of microorganisms, the cases were categorized into gram positive and gram-negative cases. Out of these cases, gram positive cases were 20(40%) and gram-negative cases were 30(60%).

The gram positive microorganism were classified into Staphylococcus aureus (4), Staphylococcus species (10), Streptococcus species(2), and Enterococcus faecalis (4) and the gram negative microorganism were classified into Proteus mirabilis (5), Klebsiella pneumonia (9), Enterobacter aerogenes (2), Escherichia coli (4), Pseudomonas aerogenes(2), Citrobacter species(3), Klebsiella oxytoca(3), Citrobacter freunde(1), Proteus vulgaris(1). Similar classification were made by Hardik V Vania et al^[16] in a study conducted in north India. From the present study, staphylococcus species is the most predominant followed by Klebsiella pneumoniae. Similar results were made by Indrajit Gupta et. Al^[17], and Ayman El Badawyet. al^[18] which showed Klebsiella pneumoniae (40%) followed by CONS (20%).

Neonatal sepsis is broadly divided into two types according to age of onset: Early onset sepsis and Late onset sepsis. The risk factors that contributed to early onset sepsis include maternal fever (9), maternal UTI (9), prolonged rupture of membrane (12), foul smell liquor (5) and that to late onset sepsis include very low birth weight (11) and preterm babies (4). Most neonates with early onset sepsis was with premature rupture of membrane while in case of late onset sepsis was very low birth weight and preterm infants as like in the study of Jun-Ho Wu et.al. from Taiwan^[19] .

The analysis also showed the sensitivity of antibiotics towards the microorganism causing neonatal sepsis and found out that cefotaxime(19), ciprofloxacin(26), ampicillin(14), gentamycin(25), amikacin(37), doxycycline(19), Vancomycin(13), cotrimoxazole(16), azithromycin(14), erythromycin(12), norfloxacin(21), amoxiclav(7), meropenem(30), piperacillin-tazobactam(30). Among these antibiotics, the most sensitive antibiotic was Amikacin and the least sensitive antibiotic was amoxiclav. When comparing with the study of Chandra Madhur Sharma et al^[20], maximum isolates were sensitive to either cefotaxime or Amikacin and a low susceptibility to commonly used antibiotics like ampicillin and gentamicin is a cause for concern.

Antibiotic resistance is a wide spread problem. In the present study too, a large number of gram positive and gram negative bacteria exhibited variable resistance to ciprofloxacin(24), cotrimoxazole(34), meropenem(20), piperacillin-tazobactam(20), amoxiclav(43), ampicillin(36), Amikacin(13), erythromycin(38), doxycycline(31), Vancomycin(37), azithromycin(36), gentamycin(25). Among these amoxiclav showed more resistance. In contrast to our study, Ashwini D et.al^[21] noticed an increasing resistance of erythromycin against most of the gram-positive isolates.

The most common gram-positive microorganism causing neonatal sepsis is staphylococcus species and its antibiotic sensitivity is given below based on sensitivity level. The sensitivity level (in mm) of antibiotics against staphylococcus species was found to be cefotaxime (26), ciprofloxacin (30.2), ampicillin(28.5), gentamycin(28.2), Amikacin(28.5), doxycycline(31.57), Vancomycin(25.7), cotrimoxazole(29.4), azithromycin(26.6), erythromycin(27), norfloxacin(28), amoxiclav(30).

The most common gram-negative microorganisms causing neonatal sepsis is Klebsiella pneumonia and its antibiotic sensitivity is given below based on sensitivity level. The sensitivity level (in mm) of antibiotics against Klebsiella pneumonia was found to be cefotaxime(21), ciprofloxacin(26.6), ampicillin(28), gentamycin(28.6), amikacin(24), doxycycline(25.6), vancomycin(28), cotrimoxazole(22), piperacillintazobactum(25.7), erythromycin(27), norfloxacin(23), amoxiclav(25), meropenem(30.1).

Consistent with other studies, Amikacin showed maximum sensitivity against gram positive microorganisms when considering the following data obtained from the present study,

1. In Staphylococcus aureus: cefotaxime (3), norfloxacin (2), ciprofloxacin (4), ampicillin (2), co-trimoxazole (2), meropenem (1), piperacillin-tazobactam (2), Amikacin (2), doxycycline (3), Vancomycin (3), azithromycin (3), gentamycin (2)

2. In Staphylococcus species, ampicillin (7), gentamycin (5), cefotaxime (7), Amikacin (9), doxycycline (7), Vancomycin (7), cotrimoxazole (5), azithromycin (5), ciprofloxacin (5), erythromycin (2), norfloxacin (5), amoxiclav (1)

3. In Streptococcus species, erythromycin (1), Amikacin (2), Vancomycin (1), ampicillin (1), doxycycline (1), gentamycin (1), azithromycin (1)

4. In Enterococcus faecalis, ciprofloxacin (4), cefotaxime (1), norfloxacin (3), azithromycin (3), Amikacin (4), gentamycin (4), Vancomycin (1), doxycycline (2), amoxiclav (2), cotrimoxazole (1), meropenem (1), piperacillin-tazobactam (1)

Highest sensitivity was recorded with meropenem and Piperacillin-tazobactam in case of gram-negative microorganisms. Recent study of Preeti Mallikarjunappa et al^[22] and Shwetha Nayak et al^[23], Meropenem 18 (94.7%) and Imipenem 12 (63.15%) were highly sensitive for gram negative organisms

I. In Proteus mirabilis, meropenem (5), piperacillin-tazobactam (5), ciprofloxacin (3), Amikacin (4), norfloxacin(3), gentamycin(4), erythromycin(2), cefotaxime(2), cotrimoxazole(1), ampicillin(1), doxycycline(2), amoxiclav(1)

II. In Klebsiella pneumonia, ciprofloxacin(3), norfloxacin(4), gentamycin(3), meropenem(8), piperacillin-tazobactam(8), Amikacin(7), cefotaxime(2). doxycycline(3), ampicillin(1), cotrimoxazole(1), amoxiclav(1)

III. In Enterobacter aerogenes, piperacillin-tazobactam (2), meropenem(2), cotrimoxazole(1), ciprofloxacin(1), norfloxacin(1), Amikacin(1), gentamycin(1)

IV. In Escherichia coli, meropenem(4), gentamycin(2), piperacillin-tazobactam(4), cotrimoxazole(2), ciprofloxacin(1), Amikacin(1), cefotaxime(1), doxycycline(1), norfloxacin(1)

V. In Pseudomonas aerogenes, cefotaxime(1), meropenem(2), amoxiclav(1), piperacillin-tazobactam(2), ciprofloxacin(1), ampicillin(1), Vancomycin(1), azithromycin(1), Amikacin(1), erythromycin(1)

VI. In Citrobacter species, meropenem(3), piperacillin-tazobactam(3), Amikacin(2), erythromycin(1)

VII. In Klebsiella oxytoca, ciprofloxacin(3), meropenem(3), Amikacin(2), piperacillin-tazobactam(2), cefotaxime(2), norfloxacin(1), gentamycin(1), doxycycline(1), cotrimoxazole(1), ampicillin(1)

VIII. In Citrobacter freundi, amoxiclav(1), meropenem(1), cotrimoxazole(1), norfloxacin(1), Amikacin(1), piperacillin-tazobactam(1)

IX. In Proteus vulgaris, Amikacin(1), piperacillin-tazobactam(1), gentamycin(1), cotrimoxazole(1), meropenem(1)

Conclusion

It is evident from the study that gram positive organism, Staphylococcus species is the leading cause of neonatal sepsis followed by Klebsiella pneumoniae, a gram negative microorganism. Most of them are resistant to multidrug antibiotics. Moreover , majority of neonates with early onset sepsis were term babies. In contrast, late onset sepsis affected mainly preterm and very low birth weight babies.

Amikacin, doxycycline and ciprofloxacin are the most sensitive antibiotics for gram positive organisms where as meropenem and piperacillin-tazobactam are for the gram negative organisms causing neonatal sepsis.

Most of the organisms have developed resistance to the commonly used antibiotics such as amoxiclav and erythromycin.

Moreover, an antibiotic policy should be formulated in the hospital. Antibiotic should be used depending on the antibiotic sensitivity pattern of the isolates.

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