Antibiotic sensitivity pattern of common bacterial pathogens in NICU and neonatal ward in Hamedan province of Iran

doi:10.4236/health.2010.26094

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Vol.2, No.6, 625-629 (2010) Health

doi:10.4236/health.2010.26094

Antibiotic sensitivity pattern of common bacterial

pathogens in NICU and neonatal ward in Hamedan

province of Iran

Alireza Monsef1, Fatemeh Eghbalian2*

1Pathology Department, Hamadan University of Medical Sciences, Hamadan, Iran

2Pediatric Department, Hamadan University of Medical Sciences, Hamadan, Iran; *Corresponding Author: eghbalian_fa@yahoo.com

Received 15 January 2010; revised 5 February 2010; accepted 8 February 2010.

ABSTRACT

Bacterial pathogens and drug resistance are

different in hospitals of each country. In this

study we determined bacterial path- ogens and

drug sensitivity in the neonatal ward and neo-

natal intensive care unit (NICU) in Ekbatan hos-

pital in Hamedan. This cross-sectional descrip-

tive study was done on 1150 hospitalized neo-

nates in neonatal and NICU wards of Ekbatan

hospital of the Hamadan university of medical

sciences from September 2004 to September

2006. Blood, cerebrospinal fluid (CSF), urine,

stool, eye excretion, synovial fluid, umbilical

secretion and ascitic fluid were evaluated. Posi-

tive cultures were evaluated for antibiotic re-

sistance with disk diffusion test methed. All of

the data in questionnaires was analyzed with

SPSS 13. Cultures including blood, urine, CSF ,

stool, eye excretion, synovial fluid, umbilical

secretion and ascitic fluid was done in 417

neonates (833 cultures). These cultures were

including: urine, 323 cases (38.8%) blood 293

cases (35.2%), CSF 180 cases (21.6%) , stool 17

cases (2%), eye secretion 16 cases (1.9%) and

other secretions (synovial, umbilical, etc) 4

cases (0.5%). The cultures were positive in 105

cases (25.2%). 60 male neonates (57.1%) and 45

female neonates (42.9%) were culture positive.

The most common microorganisms were E coli

66.7% (70 cases), Klebsiella 10.5% (11 cases).

Drug resistance was high in these microorgan-

isms. The most common microorganisms were

Ecoli and klebsiella. Drug resistance was high in

the isolated microorganisms.

Keywords: Drug Resistance; Neonate;

Bacterial Infections

1. INTRODUCTION

There has been high incidence of antimicrobial resis-

tance in bacterial infections in different parts of a coun-

try and also in any hospital [1-3]. Different mechanisms

are involved in drug resistance of microorganisms. It

may be genetic or non genetic in origin [4]. Widespread

use of broadspectrum antibiotics is the most important

factor, so antibiotic control policy has great importance

in drug resistance control [5]. The incidence of infec-

tions in hospitalized neonates is very high. After wide-

spread use of antibiotics in agriculture industry and

medicine from 1950, antibiotics resistance in common

pathogenic agents had increasingly emerged [6]. In de-

veloped countries constant investigation in this field had

done for identifying antibiotic resistance pattern. Re-

cently, the spectrum and resistance of the pathogenic

bacteria have constantly changed year after year because

of wide application of antimicrobial drugs [5-9]. It is

necessary to treat neonatal infections by empirical use of

antimicrobial drugs as soon as possible to reduce the

mortality of them. It is based on the knowledge of epi-

demiology of bacterial susceptibility pattern in each area

[6-15]. This study had done for identifying antimicrobial

susceptibility pattern in a western province of Iran in

neonatal ward to help the treatment of infected neonates.

2. MATERIAL AND METHOD

This cross-sectional descriptive study was done on 1150

hospitalized neonates in neonatal and neonatal intensive

care unit (NICU) wards of Ekbatan hospital of the

Hamadan University of Medical Sciences from Septem-

ber 2004 to September 2006. Approval from Hamadan

University of Medical Sciences was obtained prior the

study. All of the samples that had sent for bacteriological

analysis entered the study. They included blood, cere-

bro-spinal fluid (CSF), urine, stool, eye excretion, syno-

A. Monsef et al. / HEALTH 2 (2010) 625-629

626

vial fluid, umbilical excretion and peritoneal fluid.

Urine samples in neonates had obtained by suprapubic

method. In case of bacterial growth, identification of the

bacteria had done and antibiogram by disc diffusion

method had performed (Karbibauer method, Padtan Teb

antibiotic disc Company).

The quality control modalities had done on the Na-

tional Reference Laboratory of Health standards. The

antibiotics susceptibility test results had entered the

questionnaires. The data had analyzed by SPSS software

(version 13).

3. RESULTS

A total of 1150 hospitalized neonates entered the study.

There were 417 cultured samples, 239 cases (56.1%)

were male and 183 cases (43.9%) were female.

The mean age of neonates was 11.3 ± 9.3 days, (1 to 30

days).

We found 833 cultures in 417 cases, they included:

urine culture 322 (38.7%), blood culture 293 (35.2%),

CSF culture 180 (21.6%), stool culture 17 (2%), eye

excretion 16 (1.9%), others (synovial fluid, cord excre-

tion …) 5 (0.6%).

In this study 25.5% of the cultures were positive and

74.8% were negative. 57.1% (60 neonates) of positive

cultures were male and remaining 42.9% (45 neonates)

were female.

Eye excretion was the most positive culture (81.2%).

(Table 1) Table 1 shows the results of cultures.

The most frequent isolated microorganisms were

E.coli 66.7% (70 cases) and Klebciella 10.5% (11 cases)

in decreasing order (Figure 1).

Table 2 shows the frequency of isolated bacteria in

the culture.

Table 3 shows the sensitivity and resistance pattern of

bacteria cultured in urine culture. Tables 4 and 5 reveal of

the bacterial susceptibility tests in the neonates.

4. DISCUSSION

Bacterial infection is still prevalent in newborns and it is

a major medical problem [1-3]. According to the euro-

pean countries reports, its prevalence had not changes in

previous half decade, whereas bacterial etiologic agents

had changed. From 1928 to 1932 beta hemolytic strep-

tococci with 38% prevalence and staphylococcus aurous

with 28% were the most frequent causes of septicemia,

although the former is not so prevalent yet [13-14]. In

the present study Escherichia coli (Ecoli) was 66.7% and

Klebciella was 10.5%, they were the more frequent bac-

teria isolated from urine, blood and eye excretion cul

tures. Ecoli was the most frequent isolated bacteria from

urine, eye excretion and blood cultures in an order of

Table 1. Abundance distribution of positive cultures according

to the source of culture in hospitalized neonates.

Culture results

Positive

(%) NO

Negative

(%) NO

Source of culture

70 (21.7) 253 (78.3) Urine (N = 323)

15 (5.1) 278 (94.9) Blood (N = 293)

180 (100) CSF (N = 180)

3 (17.6) 14(82.4) Stool (N = 17)

13(81.2) 3(18.8) Eye secretions (N = 16)

4(80) 1(20) Other body fluid (N = 5)

66.7%

10.5% 6.7% 6.7%

3.8% 2.9% 1.9% 1.0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Ecoli

Clebsielleae

S.epidermidis

S.aurous

S.saprophyticus

Enterobacter

Streptococcus

Pseudomonas

Figure 1. Abundance distribution of isolated microorganisms

in culture positive newborns.

Table 2. Abundance distribution of isolated microorganisms

according to the source of culture in hospitalized neonates.

Source of culture

Isolated

microorganisms Urine

(N = 70)

Blood

(N = 15)

Stool

(N = 3)

Eye

secretions

(N = 13)

Other

body

fluid

(N=4)

E.coli (%77.1)54 (%53.3)8 - (46.2%)6(50%)2

Klebsiella (%12.9)9 (%6.7)1 (33.3)1 - -

S.Saprophyticus (%5.7)4 - - - -

Enterobacter (%1.4)1 (%6.7)1 (33.3)1 -

S.Aurous (%2.9)2 (%6.7)1 - (%23.1)3(%25)1

S.Epidermidis - (%26.7)4 - (%23.1)3-

pseudomonas - - (33.3)1 -

Streptocucus - - - (%7.7)1(%25)1

A. Monsef et al. / HEALTH 2 (2010) 625-629

627

77.1%, 46.2% and 53.6% respectively. These findings

are consistent with the results of Eghbalian et al. study

[15]. Yalaz et al. in Turkey studied 909 newborns, 9.1%

of them had sepsis, the isolated bacteria were: coagulase

negative staphylococcus 31.3%, fungi 19.2%, staphylo-

coccus aurous 13%, Klebsiella Pneumonia 10.5% in

decreasing order [11].

Another study of Aurangzeb et al. at 2003 revealed

112 hospitalized newborns as sepsis, 67% had positive

blood culture and E.coli was the most frequent cause

with 77.1% frequency [12]. Bacterial meningitis has

various ethologic factors and majority of authors believe

that its agents varies according to age and geographic

distribution [1,3,15,16]. In present study we did not

found any positive cerebrospinal fluid culture in the

newborns. In our study E.coli, the most prevalent iso-

lated microorganism, shows high degree resistance to

cephalosporins. It showed 75.9% resistance in urine cul-

ture to Ceftriaxone, and 60% to Ceftizoxime (Table 3).

When we separated the E.coli from the blood and eye

excretion cultures, most of them were resistant to Cepha-

losporins specially to Ceftriaxone. Also E.coli was resis-

tant to majority of aminoglycozid antibiotics including

Amikacin, Gentamycin and Tobramycin. (Tables 4, 5) In

our study the resistance of E.coli to the Ciprofloxacin,

Nalidixic acid, Nitrofurantoin and Cotrimoxazol were in

a decreasing order (Tables 3, 4, 5) .These findings are

consistent with the results of a similar study [15]. Au-

rangzeb et al. in a similar study showed high degree re-

sistance of gram negative bacteria to conventional anti-

biotics: 79.3% to Ampicillin, 74.6% to Amoxicillin,

71.6% to Ceftazidime, 50.2% to Cefotaxime, 43.2% to

Gentamycin, 34.3 to Tobramycin, 23.6% to Imipenem,

22.3% to Amikacin and 11.9% to Ciprofloxacin [12].

Also staphylococcus aurous showed 75% resistance to

Ampicillin [12]. The present study revealed high per-

centage resistance of staphylococcus aurous to cepha-

losporin and other broad spectrum antibiotics.

Table 3. Percentage of sensitivity and resistance of isolated bacteria from positive urine culture in hospitalized neonates.

Microorganisms

E.coli Clebsiellea S.Saprophyticus Enterobacter S.Aurous Antibiotic

Sensitive Resistance SencetiveResistanceSencetiveResistanceSencetive Resistance Sencetive Resistance

Ceftriaxon

7 (%1/24) 22 (%9/75) 0 6 (%100)--- --- --- --- --- ---

Amikacin

15 (%9/34) 28 (%1/65) 2 (%3/33)4 (%7/66)0 3 (%100)1 (%100) 0 0 1 (%100)

Ciprofloxacin

27 (%8/81) 6 (%2/18) 6 (%100)0 1 (%100)0 1 (%100) 0 --- ---

Jentamycin

11 (%6/25) 32 (%4/74) 2 (%25) 6 (%75) 0 3 (%100)0 1 (%100) 1 (%100) 0

Tobramycin

2 (%3/14) 12 (%7/85) 0 1 (%100)--- --- --- --- --- ---

Nalidixic acid

33 (%75) 11 (%25) 8 (%9/88)1 (%1/11)2 (%7/88)1 (%3/33)1 (%100) 0 --- ---

Trimetoprim

6 (%40) 9 (%60) 0 2 (%100)--- --- --- --- --- ---

Ceftixocim

14 (%40) 21 (%60) 0 6 (%100)0 1 (%100)1 (%100) 0 1 (%100) 0

Nitrofurantoin

26 (%7/66) 13 (%3/33) 2 (%6/28)5 (%4/71)1 (%3/33)2 (%7/66)1 (%100) 0 0 1 (%100)

Cotrimoxazol

16 (%64) 9 (%36) 4 (%7/66)2 (%3/33)2 (%100)

0 --- --- --- ---

Cefotacxim

10 (%40) 15 (%60) 0 4 (%100)1 )50(%1 (%50) 0 1 (%100) --- ---

Vanc omyc ine

--- --- --- --- 0 2 (%100)--- --- --- ---

Cephalexin

5 (%50) 5 (%50) 0 1 (%100)0 2 (%100)--- --- 0 1 (%100)

Cephtazidim

0 4 (%100) --- --- 1 (%100)0 --- --- --- ---

Ampicillin

2 (%40) 3 (%60) --- --- --- --- 0 1 (%100) --- ---

Cephalotin

4 (%100) 0 --- --- --- --- --- --- --- ---

A. Monsef et al. / HEALTH 2 (2010) 625-629

628

Table 4. Percentage of sensitivity and resistance of isolated bacteria from positive blood culture in hospitalized neonates.

Microorganisms

E.coli klebsiellea S.Epidermidis Enterobacter S.Aurous Antibiotic

Sensitive Resistance SencetiveResistanceSencetiveResistanceSencetive Resistance Sencetive Resistance

Ceftriaxon

0 4 (%100) --- --- 1 (%100)0 --- --- --- ---

Amikacin

3 (%50) 3 (%50) 0 1 (%100)1 (%100)0 1 (%100) 0 --- ---

Ciprofloxacin

5 (%100) 0 --- --- 1 (%100)0 1 (%100) 0 --- ---

Gentamycin

2 (%40) 3 (%60) 0 1 (%100)1 (%100)0 1 (%100) 0 0 1 (%100)

Nalidixic acid

3 (%75) 1 (%25) 1 (%100)0 --- --- 1 (%100) 0 --- ---

Ceftizoxime

2 (%50) 2 (%50) 1 (%100)0 1 (%50) 1 (%50) --- --- --- ---

Tetracyclin

5 (%71/4) 2 (%28/6) 0 1 (%100)--- --- 1 (%100) 0 --- ---

Nitrofurantoin

4 (%57/1) 3 (%42/9) 0 1 (%100)1 (%100)0 0 1 (%100) --- ---

Cotrimoxazol

2 (%50) 2 (%50) 1 (%100)0 --- --- 0 1 (%100) --- ---

Cloxacillin

--- --- --- --- 0 3 (%100)

--- --- --- ---

Cefotacxim

2 (%40) 3 (%6) 0 1 (%100)1 (%100)0 --- --- 0 1 (%100)

Vanc omyc ine

--- --- --- --- 4 (%100)0 --- --- --- ---

Table 5. Percentage of sensitivity and resistance of isolated bacteria from positive eye excretions culture in hospitalized neonates.

Microorganisms

E.coli S.Aurous S.Epidermidis Streptocucus Antibiotic

Sencetive Resistance Sencetive Resistance Sencetive Resistance Sencetive Resistance

Ceftriaxon

0 (%100) 4 0 (%100) 1 --- --- --- ---

Amikacin

(%60) 3 (%40) 2 (%50) 1 (%50) 1 0 (%100) 1 0 (%100) 1

Ciprofloxacin

(%33/3) 1 (%66/7) 2 --- --- 0 (%100) 1 --- ---

Gentamycin

(%33/3) 1 (%66/7) 2 (%100) 1 0 0 (%100) 1 0 (%100) 1

Ceftixocim

(%25) 1 (%75) 3 0 (%100) 1 (%50) 1 (%50) 1 --- ---

Tetracyclin

(%100) 3 0 --- --- --- --- --- ---

Amoxicillin

--- --- 0 (%100) 1 (%100) 1 0 --- ---

Cloxacillin

(%100) 1 0 0 (%100) 1 0 (%100) 2 --- ---

Erythromycin

--- --- 0 (%100) 2 (%50) 1 (%50) 1 --- ---

Cefotacxim

(%25) 1 (%75) 3 (%50) 1 (%50) 1 0 (%100) 1 (%100) 1 0

vancomycin

--- --- (%100) 1 0 (%100) 3 0 (%100) 1 0

Cephalexin

0 (%100) 1

(%50) 1 (%50) 1 (%100) 1 0 --- ---

Ampicillin

0 (%100) 2 0 (%100) 1 (%50) 1 --- ---

Chloramphenicol

--- --- (%100) 1 0 --- --- --- ---

A. Monsef et al. / HEALTH 2 (2010) 625-629

629

5. CONCLUSIONS

Our experience showed that gram-negative bacteria were

the most prevalent cause of infections in neonates in our

hospital. E.coli and Klebsiella were the most frequent

bacteria and majority of them were resistant to broad

spectrum antibiotics. Drug resistance to conventional

antibiotics is a common problem and it grows readily.

Antimicrobials must be administered conservatively

according to epidemiologic studies in the region, with

confirmed indications, and based on the results of sus-

ceptibility tests.

6. ACKNOWLEDGEMENTS

The authors would like to acknowledge the office of Vice chancellor

for research of Hamadan University of Medical Sciences for financial

support of this study. Also we would like to thank Mr. Mani Kashani K

for his assistance in statistical analysis, Dr Lak-Zadeh M and staff of

neonatal ward for their contribution and collaboration.

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