Presence of bacteria within the blood stream, continuous or transient, is known as bacteremia, while the dissemination of bacteria throughout the body with evidence of systemic responses towards microorganism with variable severity is called septicemia [
The rational use of antibiotics for varying microbiological pattern of septicemia in children warrants the need for an ongoing review of the causative organisms and their antimicrobial susceptibility pattern [
The results of bacteriological cultures and antibiotic susceptibility tests method are time consuming that can take about 2–4 days, necessitating initial empirical treatment of suspected septicemia. Therefore, knowledge of the epidemiological and antimicrobial susceptibility patterns of common pathogens in a given area helps to inform the choice of antibiotics. In accordance with this, the present study was carried out to document the bacterial etiology of septicemia and its antibiotic sensitivity profile.
A cross-sectional type of study was carried out in bacteriology laboratory of Chitwan Medical College Teaching Hospital (a 600 bed hospital) in Narayani zone of central Nepal from January 2012 to December 2013.
A total of 1630 patients during two years of study period between the ages of 1 month and 15 years having clinical features suggestive of septicemia (fever, shortness in breath, weakness, drowsiness, irritability, etc.) were enrolled in this study.
Two milliliter (mL) of blood samples from early age children and 5 mL of blood samples from late age children were collected aseptically (clearing the skin with 70% alcohol followed by 2% tincture of iodine) by clinicians, trained nurses, or laboratory staff using sterile syringe and needle by venipuncture. Immediately the blood samples were carefully transferred into the blood culture bottle containing 18 mL (if 2 mL blood sample) or 45 mL (if 5 mL blood sample) of Brain Heart Infusion broth to maintain a ratio of 1 : 10 of blood to broth. The blood culture bottles were labeled with the patient’s name, age/sex, identification number, date, and time of collection.
The Brain Heart Infusion broth inoculated with blood was transported to the laboratory and incubated at 37°C in aerobic condition. All the bottles were examined for turbidity, hemolysis, and pellicle formation and subcultures were made on to sheep blood agar, chocolate agar, and MacConkey agar after overnight aerobic incubation. Blood agar and MacConkey agar plates were incubated overnight at 37°C in aerobic atmosphere while chocolate agar plates were incubated overnight at 37°C in 5% carbon dioxide (CO2). Culture bottles were observed for turbidity and blind subcultures were performed each day. Final subcultures were done on the 10th day before reporting negative. Growth obtained was examined for colony and Gram-staining characteristics. Conventional biochemical tests were performed and identification of the organism was done by using standard microbiological methods [
All the isolates grown were subjected to antibiotic susceptibility testing by modified Kirby-Bauer disk diffusion method in compliance with Clinical and Laboratory Standards Institute (CLSI) guidelines using Mueller-Hinton agar standard media. The inhibition zone standards for antimicrobial susceptibility were considered from tables for interpretative zone diameters of CLSI [
Antibiotic disks (HiMedia Laboratories, Pvt. Limited, India) used were as follows: oxacillin (1
Identification of methicillin resistant
Verbal consent in local language for this study was taken from the guardians of participating children. This study was approved by the Institutional Review Committee of Chitwan Medical College, Bharatpur, Nepal.
Statistical analysis was performed using SPSS-11.5 version. Association of septicemia with gender and type of causative agents were assessed by using the chi-square test and others.
During two years of study period, 1630 children aged between 1 month and 15 years were enrolled, from whom positive growth of bacteria was obtained in 172 cases (10.6%). Of total enrolled cases, 1016 (62.3%) were males and 614 (37.7%) were females, whereas, out of total positive cases, 94 (54.6%) were males and 78 (45.4%) were females which was found to be statistically significant (
Distribution of total and positive cases.
Age | Total cases ( |
Positive cases ( |
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Male | Female | Male | Female |
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1–11 months | 210 | 136 | 28 | 29 | 0.028 |
1–5 years | 295 | 187 | 26 | 22 | |
6–10 years | 269 | 144 | 18 | 15 | |
11–15 years | 242 | 147 | 22 | 12 | |
|
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Total | 1016 (62.3%) | 614 (37.7%) | 94 (54.6%) | 78 (45.4%) |
Gram-positive as well as Gram-negative organisms were isolated from the blood samples. Gram-positive organisms constituted 47.7% while Gram-negative organisms constituted 52.3% but the difference was not found to be statistically significant (
Distribution of bacterial isolates.
Isolates | 1–11 months | 1–5 years | 6–10 years | 11–15 years | Total (%) |
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Gram-positive |
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|
|
|
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Coagulase negative staphylococcus (CoNS) | 30 | 16 | 14 | 8 | 68 (39.5) | |
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3 | 2 | 1 | 3 | 9 (5.2) | |
|
1 | 1 | 2 | 1 | 5 (3.0) | |
Gram-negative |
|
|
|
|
|
|
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8 | 8 | 6 | 8 | 30 (17.5) | |
|
0 | 3 | 0 | 1 | 4 (2.3) | |
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2 | 8 | 1 | 2 | 13 (7.6) | |
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8 | 4 | 3 | 2 | 17 (9.9) | |
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1 | 2 | 3 | 2 | 8 (4.6) | |
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3 | 2 | 2 | 2 | 9 (5.2) | |
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1 | 2 | 1 | 5 | 9 (5.2) | |
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Total (%) | 57 (33.1) | 48 (27.9) | 33 (19.2) | 34 (19.8) | 172 (100) |
Vancomycin and teicoplanin were found to be hundred percent effective against Gram-positive isolates. Amikacin was found to be very good alternative antibiotic for Gram-positive as well as Gram-negative isolates with very minor resistance to it. Most of the Gram-positive isolates were resistant to erythromycin, cotrimoxazole, and
Antibiotic resistance profile of isolates.
Isolated organisms | Rate of resistance to different antibiotics tested | |||||||||||||||||||
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OX | FOX | VAN | TEI | E | CD | P | CFX | COT | G | AK | OF | CFM | CTX | CAZ | PI | PIT | CAR | AMX | NA | |
Coagulase negative |
29.4 | 35.3 | 0 | 0 | 51.5 | 26.5 | 88.2 | 80.9 | 67.6 | 55.9 | 2.9 | 32.4 | X | X | X | X | X | X | X | X |
|
33.3 | 44.4 | 0 | 0 | 55.6 | 22.2 | 88.9 | 77.8 | 44.4 | 44.4 | 0 | 22.2 | X | X | X | X | X | X | X | X |
|
0 | X | 0 | 0 | 60.0 | 0 | 100 | X | X | 60.0 | 20.0 | 20.0 | X | X | X | X | X | X | X | X |
|
X | X | X | X | X | X | X | X | 56.7 | 26.7 | 10.3 | 20.0 | 76.7 | 66.7 | 77.3 | 60.0 | 43.3 | X | 83.3 | X |
|
X | X | X | X | X | X | X | X | X | 52.9 | 11.7 | 35.3 | 58.8 | 70.6 | 58.8 | 76.5 | 52.9 | 41.2 | 100 | X |
|
X | X | X | X | X | X | X | X | 50.0 | 75.0 | 0 | 25.0 | 0 | 50.0 | 50.0 | 50.0 | 25.0 | X | 100 | X |
|
X | X | X | X | X | X | X | X | 69.2 | 61.5 | 23.0 | 61.5 | 69.2 | 15.4 | 23.0 | 61.5 | 38.5 | X | 77.0 | X |
|
X | X | X | X | X | X | X | X | 62.5 | 50.0 | 0 | 37.5 | 50.0 | 37.5 | 37.5 | 62.5 | 37.5 | X | 100 | X |
|
X | X | X | X | X | X | X | X | 77.8 | 66.7 | 11.1 | 33.3 | 22.2 | 55.5 | 66.7 | 77.8 | 55.5 | X | 77.8 | X |
|
X | X | X | X | X | X | X | X | 44.4 | 22.2 | 0 | 33.3 | 33.3 | 55.5 | 44.4 | 55.5 | 22.2 | X | 88.9 | 33.3 |
Note: OX: oxacillin, FOX: cefoxitin, VAN: vancomycin, TEI: teicoplanin, E: erythromycin, CD: clindamycin, P: penicillin G, CFX: cephalexin, COT: cotrimoxazole, G: gentamicin, AK: amikacin, OF: ofloxacin, CFM: cefixime, CTX: cefotaxime, CAZ: ceftazidime, PI: piperacillin, PIT: piperacillin-tazobactam, CAR: carbenicillin, AMX: amoxycillin, NA: nalidixic acid, X: not tested.
Bacterial infections are major causes of morbidity and mortality in children. The detection, identification, and susceptibility testing of a causative species of bacteremia are essential for the proper management of the patient. In this study, among 1630 children aged between 1 month and 15 years enrolled, positive growth of bacteria was found in 172 cases (10.6%). High culture positivity rates have been reported by investigators from other countries, 44.9% from Nigeria [
In current study, the bacterial sepsis was suspected more in male children (62.3%) than in female children (37.7%) and the higher rate of bacterial isolation in males (54.6%) compared to females (45.4%) seen in this study was found to be statistically significant (
The causative organisms vary from place to place. In this study, Gram-positive as well as Gram-negative organism was isolated from the blood samples. Gram-positive organisms constituted 47.7% while Gram-negative organisms constituted 52.3% but the difference was not found to be statistically significant (
Coagulase negative staphylococci (CoNS) were found to be the most common etiology of septicemia in the present study. Our result is in agreement with other studies that reported CoNS as the most common bacteria isolated from children with sepsis [
Though penicillin is a primary drug against Gram-positive organisms, such isolates in our study exhibited 80% resistance to it. This result concurs with the report of Karki et al. from Nepal, who also noticed that
Despite widespread use of aminoglycosides (gentamicin and amikacin), development of resistance to this class of antibiotics remained low compared to other antimicrobial agents. Amikacin was found to be a very good alternative for Gram-positive as well as Gram-negative isolates with very minor isolates being resistant to it while nearly half of the isolates were resistant to gentamicin. This observation was confirmed by the reports that the majority of Gram-positive as well as Gram-negative blood stream isolates were susceptible to amikacin [
Resistance to macrolide (erythromycin) is also increasing; more than 50% of isolates were resistant to erythromycin and most of the Gram-positive isolates were resistant to cotrimoxazole in this study. Similar result indicating high resistance to erythromycin and cotrimoxazole was also documented by Rathod et al. from India [
Third generation cephalosporins were also less effective against Gram-negative isolates in this study. The resistance of 15.4% was exhibited by
Nowadays, the methicillin resistance in CoNS and
The emergence of quinolone resistance in the most common
There was no attempt to isolate anaerobic bacteria in this study although they might have been the cause of bacteremia and septicemia in some of the cases where no aerobic bacteria were detected in blood cultures. Anaerobic bacteria were reported to constitute 18% of the total number of isolates from blood [
This study has highlighted the burden of bacterial etiology for septicemia among children in a tertiary care center of central Nepal. However, since the spectrum of pathogens, incidence of diseases, and antimicrobial susceptibility change over time and places, the data should be monitored continuously to allow an appropriate clinical response and healthcare planning. This study highlights the variable nature of antibiotic susceptibility patterns. Therefore, it is advisable to continuously evaluate the resistance pattern of isolates so as to make a rational use of antibiotics.
The present study identified the burden of MRSA infection among septicemic children. Regular monitoring of antibiotic susceptibility pattern of MRSA and selection of a definite antimicrobial agent may be helpful for reducing the incidence of MRSA infections in septicemia in children. It is also important for clinicians to be aware of the existence of the bacterial strains showing decreased fluoroquinolone susceptibility.
The authors declare that they have no conflict of interests.
The authors are deeply indebted to the children and their parents for participating in this study. They also thank all the laboratory staff of the Bacteriology Department of Chitwan Medical College Teaching Hospital (CMCTH) for their kind support in the collection of data and performing the necessary laboratory tests during the study.