Int J Pharm Pharm Sci, Vol 7, Issue 1, 185-190Original Article


STUDY OF PREVALENCE AND ANTIMICROBIAL SUSCEPTIBILITY PATTERN OF BACTERIAL ISOLATES IN A TERTIARY CARE HOSPITAL

C. M. DIVYASHANTHI*1, S. ADITHIYAKUMAR2, BHARATHI. N3

1*Assistant professor, Department of Pharmacology, Vinayaka Mission’s Medical College and Hospital, Keezhakasakudimedu, Karaikal-609609, Pondicherry (U. T), India, 2&3Pre-Final year MBBS students, Vinayaka Mission’s Medical College and Hospital, Keezhakasakudimedu, Karaikal-609609, Pondicherry (U. T), India.
Email: dishanthii@gmail.com

Received: 22 Oct 2014 Revised and Accepted: 20 Nov 2014

ABSTRACT

Objective: Many human illnesses are bacterial in origin which can be treated with appropriate antibiotics and selection of these is mostly based on culture and sensitivity. The problem of antimicrobial resistance has burgeoned throughout the world both in inpatients and outpatients. We must work together to preserve the power of antimicrobials so as to use these effectively in treating diseases. The aim of the study is to find out the prevalence of infection and sensitivity pattern among bacterial pathogens in a tertiary care hospital.

Methods: This retrospective study was carried out in Vinayaka Missions Medical College and Hospital, Karaikal, Puducherry (U. T) to study the culture and sensitivity pattern of clinical isolates from blood, urine, sputum, wound, ear/throat swab for one year (June 2012- June 2013). The positive cultures and their antibiotic susceptibility testing were performed under the guidelines of Clinical and Laboratory Standard Institute (CLSI). The lab data from Microbiology department were utilized and filled in a proforma and analyzed.

Results: Out of 788 samples, 296 were culture positive. Isolated bacteria were mostly Gram negative organisms (GNO) of which Klebsiella (41.55%) was commonly followed by Pseudomonas (15.20%), Escherichia coli(4.05%) and Proteus (3.71%). Among Gram positive organisms (GPO) Staphylococcus (35.47%) was common. Imipenem (100%), Gentamycin (90.20%), Amikacin (89.14%), were the antimicrobials most sensitive for GNO, while Ceftriaxone (100%), Cefotaxime(100%),Nitrofurantoin(96.15%) and Linezolid(92.13%) were most sensitive for GPO. Widespread resistance to Nalidixic acid (99%),Ampicillin (85.90%), Cefuroxime (75%) is seen in both groups, while Cefazolin(79.25%) and Norfloxacin(83%) was noted for GNO, resistance to Amoxicillin with clavulanic acid (81.66%) and Imipenem(55.55%) was noted for GPO.

Conclusion: The technical abilities to detect novel, resistant mechanisms and to overcome the microbial resistance has to be improved. Antibiotic policies agreed among clinicians, microbiologists and pharmacologists will guide good prescribing, provide maximum coverage for treating infections and ensure antibiotic cycling.

Keywords: Surveillance, Prevention, Drug resistance, Antibiotic cycling.

INTRODUCTION

Antimicrobial resistance is a modern warfare against trillions upon trillions of microorganisms which is constantly evolving [1]. Antimicrobial drugs includes all agents that work against a variety of microorganisms such as bacteria, viruses, fungi and parasites. Antimicrobial resistance is when bacteria or other microbes become resistant to the effects of a drug after being exposed to them [2]. Each antimicrobial agent is injurious only to a certain segment of the microbial world. So, for a given antibacterial agent there are some species of bacteria that are susceptible and others are not. Bacterial species insusceptible to a particular drug are naturally resistant. Species that were once sensitive but eventually become resistant to it are said to have acquired resistance. Acquired resistance affects a subset of strains in the entire species; this explains the different resistance pattern of the same species in different location [1].

Antibiotics were too widely, too cheaply and indiscriminately used worldwide [3]. In India, the main reason for development of antimicrobial resistance could be due to irrational use of antibiotics, over the counter availability of higher / broader antimicrobial agents, higher prevalence of infection and poor monitoring of antibiotic susceptibility surveillance in hospitals [4]. If resistant strains spreads widely, important group of drugs lose their efficacy and would render many infections untreatable [5]. Apart from medical consequences of antibiotic resistance, there is direct cost to society. Newer drugs are costlier and are difficult to manufacture. Hence prevention of resistance outbreaks makes the health care society a spendthrift [3], thus costing the nation a huge sum of money. The problem of resistance is global and need to be tackled on that scale [3]. The intention of the study is to find out the prevalence of common infection and sensitivity / resistance pattern among bacterial pathogens in a tertiary care hospital situated in a coastal area of Karaikal, Puducherry.

MATERIALS AND METHODS

This retrospective study was carried out in the Department of Pharmacology along with Department of microbiology, Vinayaka Missions Medical College and Hospital, Karaikal-09, Puducherry, U. T. The permission to the study was taken from the Principal of the institution. The data comprising a total of 788 samples collected over a period of one year (June 2012 to June 2013) was taken. Isolates from clinical specimen such as urine, pus, blood, sputum, wound, ear / throat swabs, and peritoneal fluid sample were analyzed. The positive cultures and their antibiotic susceptibility testing were performed under the guidelines of Clinical and Laboratory Standard Institute (CLSI).

The isolates were subjected to antibiotic susceptibility testing by disc diffusion technique after positive culture. The lab data from Microbiology department were utilized and filled in a proforma and analyzed. The Antimicrobial agents used and their drug content in disc are shown in the Table1.

RESULTS

Study population

During the study period, total of 788 samples were received for culture and sensitivity test in the Department of Microbiology in Vinayaka Missions Medical College and Hospital, Karaikal. From the total of 788 specimen obtained, 296 (37.56%) were cultured positive and remaining 492(62.4%) were cultured negative. Out of 296 positive samples, 156 (52.7%) are from male patient and 140 (47.29%) are from female patient.

Fig. 1: Represents gender wise distribution of cultural isolates

Stratification based on age indicates more samples are from the age group of 31-40, 41-50 & 51-60.

Prevalence & Characteristics of infection

Out of 296 positive samples, based on microscopy and culture characters 191 were Gram Negative isolates and 105 were Gram positive isolates.

Fig. 2: Represents Gram staining and cultural characteristics of cultural isolates.


Table 1: Antimicrobial agents used and their drug content in the disc

Symbol Anti microbial agent Disc content
AK Amikacin 30 mcg
CF Ceftazidime 30 mcg
AC Amoxycillin/Clavulanic acid 30 mcg
CIP Ciprofloxacin 5 mcg
CPM Cefepime 30 mcg
CN Cephoxitin 30 mcg
CXM Cefuroxime 30 mcg
CZ Cefazolin 30 mcg
IPM Imipenem 10 mcg
MR Meropenem 10 mcg
NX Norfloxacin 10 mcg
NIT Nitrofurantoin 300 mcg
OF Ofloxacin 5 mcg
CTX Cefotaxime 30 mcg
CFM Cefixime 5 mcg
CTR Ceftriaxone 30 mcg
CD Clindamycin 2 mcg
GEN Gentamycin 10 mcg
LZ Linezolid 30 mcg
TEI Teicoplanin 30 mcg
VA Vancomycin 30 mcg
CEP Cephalothin 30 mcg
NA Nalidixic acid 30 mcg
LE Levofloxacin 5 mcg
R Rifampicin 5 mcg
AMX Amoxycillin 20 mcg
AMP Ampicillin 10 mcg
CTR Ceftriaxone 30 mcg

Table 2: Represents Age wise distribution of cultural isolates in this study.

Age Positive cultural samples
0-10 12
11-20 15
21-30 32
31-40 58
41-50 59
51-60 55
61-70 44
71-80 16
81-90 4
90-100 1

The most predominant Genus/Species in Gram Negative isolates are Klebsiella - 121 (41.55%), Pseudomonas – 45 (15.20%), Escherichia coli – 12 (4.05%) & Proteus vulgaris – 11 (3.71%). Similarly the most predominant Genus/Species in Gram Positive isolates is Staphylococcus – 105 (35.47%).

^organism of least /negligible count was not included in this study as certain infections are uncommon and rare.

The positive isolates are obtained from following samples: Urine (112*), Pus (116*), Sputum (41*), Blood (8*), Ear swab (7*), Throat swab (1*), Peritoneal fluid (1*) & Wound (10*).

*indicates no. of positive samples obtained from each type of sample.

The above fig. 3 indicates that Klebsiella is the most common causative organism of urinary tract infection (UTIs) and Staphylococcus being the most common causative organism of pyogenic infections.

Antibiotic Resistance

Antibiotic resistance pattern revealed that the majority of bacterial isolates were resistant to multiple anti-bacterial agents.

Widespread resistance to nalidixic acid (99%), Ampicillin (85.90%), Cefuroxime (75%) is seen in both Gram negative isolates and Gram positive isolates. Widespread resistance to Cefazolin(79.25%) and Norfloxacin(83%) was noted for Gram negative isolates and widespread resistance to Amoxicillin with clavulanic acid (81.66%) and Imipenem(55.55%) was noted for Gram positive isolates

Fig. 3: Represents distribution of isolates, based on type of sample and organism isolated and cultured


Fig. 4: Resistance pattern of Klebsiella isolates


Fig. 5: Resistance pattern of Pseudomonas isolates


Fig. 6: Resistance pattern of Proteus isolates


Fig. 7: Resistance pattern of E. coli isolates

Antibiotic Sensitivity

Antibiotic sensitivity pattern indicates the effective drugs to manage multidrug resistant bacterial infections in patients.

Imipenem (100%), Gentamycin (90.20%), Amikacin (89.14%), were most sensitive for Gram Negative isolates, while Ceftriaxone(100%), Cefotaxime(100%), Nitrofurantoin (96.15%) and Linezolid (92.13%) were most sensitive for Gram positive isolates.

DISCUSSION

The discovery of antibiotics has revolutionized the management of infectious diseases more efficiently and timely. As by the famous saying “Every invention and discovery has its own downside”, the bacteria are developing resistance to those antibiotics, becoming recalcitrant and troublemaker to treatment.

In this study, appalling results were obtained about the Sensitivity/ Resistance pattern of microbes to antibiotics. The number of positive isolates was 296 out of 788 samples with an infection rate of 37.56%. This is quite higher compared to a other study by Mehta A et al [6]. which showed an infection rate of 20%. The age wise distribution of clinical isolates of positive cultures showed that most of the patients were of the 31-50 years of age. This is similar to Rajat Rakesh M et al [4], Balan K et al [7] and Rashid A et al [8].

The maximum clinical isolates obtained were pus samples followed by urine and sputum samples. This is in line with Balan K et al [7] and Shenoy S et al [9].

On evaluating the common bacterial isolates, Klebsiella was found to be the commonest among urine isolates followed by Staphylococcus aureus, Escherichia coli and Pseudomonas which is comparable to Bajaj JK et al [10]. Klebsiella is most commonly isolated from urine sample which is similar to other studies by Kaushal V Sheth et al [5], Bajaj JK et al [10] and Iffat Javeed et al [11].

Among the wound/swab isolates, Klebsiella was the predominant gram negative bacteria followed by Pseudomonas and E. coli. This is similar to the study done at the same institution, on Surgical Site Infections by Ramesh A et al, 2012 [12]. This result is in contrast to Girish M. B et al [13] where E. coli was the predominant gram negative bacteria.

The isolates from pus samples showed staphylococcus aureus was the commonest organism which is comparable to the studies by Vibha B. Tiwari et al [3] and most other articles. This is in contrast to Sumita Rajeevan et al [14].

Among sputum samples, Klebsiella is more common than Staphylococcus aureus and Pseudomonas. Predominance of Klebsiella over other isolates is similar to Kaushal V Sheth et al [5] and Sriram S et al [15] and is in contrast to Vibha B. Tiwari et al [3].

Among the blood samples isolated Staphylococcus aureus was the predominant followed by Klebsiella and E. coli, comparable to studies by Iffat Javeed et al [11], Sumita Rajeevan et al [14], Vanitha Rani N et al [16], Amita Jain et al [17] and Shreshtha et al [18]. A few positive cultures with Proteus vulgaris were obtained in few pus /urine isolates.

Gram negative isolates and their resistance pattern: The microbes which were positively cultured in our study was Klebsiella, Staphylococcus aureus, Pseudomonas, Escherichia coli, Proteus vulgaris. Similar to Kaushal V Sheth et al [5] and Raval PN et al [19] Gram negative bacteria predominate Gram positive cocci in our study. On observing the resistance pattern-

Table 3: Resistance pattern of cultural isolates

Proteus Pseudomonas Klebsiella E. coli Staphylococci
AK 30 2.57 1.754 9.09 8.602
CF 0 21.43 100 19.04
AC 100 81.66
CIP 10 12.9 38.28 62.25 13.15
CPM 66.66 93.34 62.86 80 50
CN 33.33 100 96.87
CXM 90 75 75 66.66
CZ 75 95.45 72.98 75 39.13
IPM 0 0 0 0 55.55
MR
NX 66.66 69.23 5 100 27.27
NIT 50 47.06 6.451 0 3.85
OF 66.66 33.34 39.62 75 41.67
CTX 50 27.28 47.61 57.14
CFM 54.55 83.33 68.49 100 16.167
CTR 0 50 80
CD 0 20.77
GEN 20 9.375 15.51 0 30
LZ 0 0 7.86
TEI 50 20.89
VA 15.78
CEP 100 91.66 97.36
NA 100 100 64 100
LE 20 14.28 30
R 100 44.45
AMX 54.55
AMP 100 85.72 72.72
CTR 0

Table 4: Sensitivity pattern of cultural isolates

AMA Proteus Pseudomonas Klebsiella E. Coli Staphylococcus
AK 70 97.43 98.24 90.9 91.39
CF 100 78.57 0 80.95
AC 0 18.33
CIP 90 87.09 61.72 37.5 86.84
CPM 33.33 6.66 37.14 20 50
CN 66.66 3.125
CXM 10 25 25 33.33
CZ 25 4.54 27.02 25 60.86
IPM 100 100 100 100 44.44
MR
NX 33.33 30.769 46 0 72.72
NIT 50 52.94 93.54 100 96.15
OF 33.33 66.66 60.37 25 58.33
CTX 50 72.72 52.38 42.85 100
CFM 45.45 16.66 31.5 0 83.33
CTR 100 50 20
CD 100 69.23
GEN 80 90.62 84.48 100 89.33
LZ 100 100 92.13
TEI 50 79.1
VA 84.21
CEP 0 8.33 2.63
NA 0 0 36 0
LE 80 85.71 70
R 0 55.55
AMX 45.45
AMP 0 14.28 27.27
CTR 100

Klebsiella showed a high level of resistance to Cephalothin (97.36%), Cefoxitin (96.87%), Ceftriaxone (80%), Cefuroxime (75%), Cefazolin (72.9%) and Ampicillin (30%). The resistance shown by Klebsiella was also observed in other studies Kaushal V Sheth et al [5], Iffat Javeed et al [11], Li-Yang Hsu et al [20], Amin A et al [21].

Pseudomonas was resistant to Ampicillin (100%), Nalidixic acid (100%), Amoxycillin with Clavulanic acid (100%), Cefoxitin (100%), Cefazolin (95.45%), Cefepime (93.34%) and Cephalothin. This is similar to Iffat Javeed et al [11]. Resistance to Cefepime was also observed by Mohanasundaram KM et al [22] and Basanti Pathi et al [23].

Escherichia coli was resistant to Cefixime (100%), Nalidixic acid (100%), Ceftazidime (100%), Cefipime (80%), Cefuroxime (75%), Cefazolin (75%) and Ofloxacin (75%). This was also identical to Li-Yang Hsu et al [20], Mangaiarkkarasi. A et al [24] and Oteo J et al [25].

Proteus was resistant to Cephalothin (100%), Nalidixic acid (100%), Cefaolin (75%), Cefipime (66%), Norfloxacin (66%), Ofloxacin (66%).

Most gram negative were resistant to first and second generation Cephalosporins and resistance to third generation Cephalosporins is now emerging which is due to Beta lactamase activity by the bacteria. This was similar to the study of Maksum Radji et al [26] and Vera Vlahović-Palčevski, [Croatia] et al [27]. Vera Vlahović-Palčevski et al [27] quotes that third or fourth generation Cephalosporins and Amoxiclav were most misused antibiotics.

Gram negative isolates and their sensitivity pattern

Antibiotics which retained their usefulness and showed less resistance to these gram negative isolates in our study were Imipenem (0% /0% /0%), Amikacin (1.754% /2.57% /9.09%) and Gentamicin (15.51% /9.37% /0%) against Klebsiella, Pseudomonas and E. coli respectively. This is similar to Kaushal V Sheth et al [5], Balan K et al [7], Iffat Javeed et al [11], Girish M. B et al [13], Amin A et al [21], R. Shyamala et al [28], Nathisuwan S et al [29] and Muhammad Naeem et al [30].According to a study conducted by Hasan AS et al [31], Amikacin and cefotaxime is still effective against Gram negative bacterial infections. In another study conducted by Saghir H et al [32], Imipenem was the most effective drug against Gram negative strains. This is also in line with Kaushal V Sheth et al [5], Mehta A et al [6], Sumita Rajeevan et al [14], Sriram S et al [15] and Gaurav Dalela et al [33].

Specifically, Pseudomonas aeruginosa was sensitive to Aminoglycosides, Fluoroquinolones. This effectiveness is also reported by Kaushal V Sheth et al [5], Basanti Pathi et al [23].

Similarly E. coli was sensitive to Gentamicin (100%), Imipenem (100%), Nitrofurantoin (100%) and Amikacin (100%). Sensitivity of E. coli to Imipenem was also reported by Mangaiarkkarasi. A et al [24], Syed Mustaq Ahmed et al [34]. Similarly Sensitivity to Nitrofurantoin was also reported by Mangaiarkkarasi. A et al [24], Gaurav Dalela et al [33], Bonten M et al [35], and to Amikacin was also reported Mangaiarkkarasi. A et al [24], Mutate AJ [36].

Gram positive isolate and its resistance pattern

Staphylococcus aureus shows resistance to Amoxicillin with Clavulanic acid (81.66%) and Ampicillin (72.72%) and Imipenem(55.55%). Resistance to Ampicillin was also noted by Shrestha S et al [18]. Few of Staphylococcus aureus isolates about 15.78% of total 19, shows a low resistance to Vancomycin similar to Vanitha Rani N et al [16], Li-Yang Hsu et al [20] and M. Mehdinejad et al [37].

Gram positive isolate and its sensitivity pattern

Regarding effectiveness of antibiotics for Staphylococcus aureus Linezolid, Amikacin, Nitrofurantoin and Vancomycin were much effective. This sensitivity of Staphylococcus aureus to Linezolid was observed similarly by Sriram S et al [15] and Raval PN et al [19]. Sensitivity of Staphylococcus aureus to Vancomycin was observed similarly by Vanitha Rani N et al [16] and Raval PN et al [19]. Sensitivity to Amikacin was noted by Sriram S et al [15].

CONCLUSION

The results of the present study highlights the alarming development of resistance to almost all the drugs with a very few exception of drugs used in this study. Non empirical /inappropriate antibiotic use contributes to the emergence of antimicrobial resistance in bacteria both Gram negative and Gram positive organisms. In developing countries, antibiotics are prescribed for 44-97% of patients in hospital, often inappropriately. This was reported earlier by Raval PN et al [19], Vera Vlahović-Palčevski et al [27], Hu S et al [China] [38], Ansari F et al [Iran] [39], Maksum Radji et al [40] and Baktygul Kambaralieva et al [Kyrgyz Republic ] [41].

Shockingly, India has one of the highest rates of Gram negative bacillary resistance in the world according to Vibha B. Tiwari et al [3], Mathai D et al [42]. This is due to over reliance on broad spectrum antibiotics, which is because of diagnostic uncertainty among physicians and non-empirical or inappropriate use of antimicrobial agents. Optimal selection of antibacterial agents would decrease the emergence of resistance and would reduce the pharmacy expenditure. Existing and future medical community, health care professionals, Government should address this emerging problem and curb this at its root or else a scenario of pre antibiotic era in near future is inevitable.

Limitation of the study

Antibiotic disc sensitivity test may vary with hospital settings, where infection rate depends on environment and locality, type of infection, its control practices and antibiotic use. Thus, these factors would limit the applicability of this finding to other locality/hospital settings.

CONFLICT OF INTERESTS

We have no conflict of interests.

ACKNOWLEDGEMENT

We would like to express our sincere thanks and gratitude to Dr. Samuel Gnanadoss (Medical director), Dr. R. Thirunavukkarasu (Principal) and Dr. Syed Maroof Saheb (Medical superintendent) and Dr. Vijayakumar Nair (Vice Principal) for permitting us to conduct this study.

REFERENCES

  1. American Academy of Microbiology. Antibiotic resistance: an ecological perspective on an old problem. Based on a colloquium held in the Fondation Mérieux Conference Center in Annecy, France, 12 to 14 October 2008. ASM Press, Washington, DC; 2009.
  2. http://www.fda.gov/animalveterinary/guidance compliance enforcement/ guidance for industry/ucm216939. htm
  3. Vibha B Tiwari, BM Kuril, MK Doibale. Study of microbiological surveillance data and antibiotic sensitivity patterns for isolates collected at a single tertiary hospital. Int J Recent Trends Sci Technol 2013;7(3):91-9.
  4. Rajat Rakesh M, Ninama Govi nd L2, Mistry Kalpesh, Parmar Rosy, Patel Kanu, Vegad MM. Antibiotic resistance pattern in Pseudomonas aeruginosa species isolated at a tertiary care hospital. Ahmadabad 2012;2(2):156-9.
  5. Kaushal V Sheth, Tejas K Patel. Antibiotic sensitivity pattern of bacterial isolates from the icu of a tertiary care hospital in India. Trop J Pharm Res 2012:11(6):991 nosa in a tertiary care hospital. J Microbio Immunol infect 2007;40;45-9.
  6. Mehta A, Rosenthal VD, Mehta Y, Chakravarthy M, Todi SK, Sen N, Sahu S, et al. Device-associated nosocomial infection rates in intensive care units of seven Indian cities. Findings of the Int Nosocomial Inf Control Consortium (INICC)-J Hosp Infect 2007;67(2):168-74.
  7. Balan K, Sujitha K, Vijayalakshmi TS. Antibiotic susceptibility pattern of gram negative clinical isolates in a teaching tertiary care hospital. Sch J App Med Sci 2013;1(2):76-9.
  8. Rashid A, Chowdhury A, Rahman Sufi HZ, Begum SA, Muazzam N. Infections by Pseudomonas and antibiotic resistance pattern of the isolates from Dhaka Medical college Hospital. Bangladesh J Med Microbio 2007;1:48-51.
  9. Shenoy S, Baliga R, Saldanha DR, Prashanth HV. Antibiotic sensitivity pattern of Pseudomonas aeruginosa strains isolated from various clinical specimen. Indian J Med Sci 2002;56:27–30.
  10. Bajaj JK, Karyakarte RP, Kulkarni JD, Deshmukh AB, Aurangabad. Changing aetiology of urinary tract infections and emergence of drug resistance as a major problem. J Commun Dis 1999;31(3):181-4.
  11. Iffat Javeed, Rubeena Hafeez amd M, Saeed Anwar. Antibiotic susceptibility pattern of bacterial islolates from patients admitted to a tertiary care hospital in Lahore. Biomed 2011;27(18):19–23.
  12. Ramesh A, Dharini R. Surgical site infections in a teaching hospital. Clinico, Microbiological and Epidemiological profile. Intern J Biol Med Res 2014;3:2050-3.
  13. Girish M Bengalorkar, TN Kumar. Culture and sensitivity pattern of micro-organism isolated from diabetic foot infections in a tertiary care hospital (Original Article). Int J Curr Biomed Pharm Res 2011;1(2):34-40.
  14. Sumita Rajeevan, Syed Mustaq Ahmad, PT Jasmin. Study of prevalence and antimicrobial susceptibility pattern in blood isolates from a tertiary care hospital in North Kerala. India Int J Curr Microbiol App Sci ISSN 2014;3:655-62.
  15. Sriram S, Vidhya D, Gisha mary George, Manjula Devi AS, Rajalingam BR, Shivashankar V, et al. Study on bacterial spectrum and antibiotic resistance of pathogens at a private corporate hospital. Univeral J Pharm ISSN 2013;2(3):63-8.
  16. Vanitha Rani N, Kannan Gopal, Venkata Narendra M, Vishwakanth D, VRD Nagesh, Yogita M, et al. A retrospective study on blood stream infections and antibiotic susceptibility patterns in a tertiary care teaching hospital. Int J Pharm Pharm Sci 2012;4(1):543-48.
  17. Amita Jain, Astha Agarwal, Raj Kumar Verma, Shally Awasthi, KP Sing. Intravenous device associated blood stream staphylococcal infection in paediatric patients. Indian J Med Res 2011;134:193-9.
  18. Shrestha S, Shrestha NC, Dongol Singh S, Shrestha RPB, Kayestha S, Shrestha M, et al. Bacterial isolates and its antibiotic susceptibility pattern in NICU. Kathmandu Univ Med J 2013;41(1):66-70.
  19. Raval PN, Patel PG, Patel BV, Soni ST, Bhatt SK, Vegad MM, et al. Microbiological Surveillance of Intensive care units in a tertiary care teaching hospital –western India. Int J Microbiol Res 2012;4(7):270-4.
  20. Li-Yang Hsu, Thean-Yen Tan, Roland Jureen, Tse-Hsien Koh, Prabha Krishnan, Raymond Tzer-Pin Lin, et al. Antimicrobial drug resistance in singapore Hospitals. Emerg Infect Dis 2007;13(12):1944–7.
  21. Amin A, Ghumro PB, Hussain S, Hameed. A Prevalence of antibiotic resistance among clinical isolates of Klebsiella pneumoniae isolated from a tertiary care hospital in pakistan. Malaysian J Microbiol 2009;5(2):81-6.
  22. Mohanasundaram KM. The antimicrobial resistance pattern in the clinical isolates of Pseudomonas aeruginosa in a tertiary care hospital. J Clin Diagn Res 2011;5(3):491–4.
  23. Basanti Pathi, Surya N Mishra, Kumudini Panigrahi, Nirmala Poddar, Priya R Lenka, Bandana Mallick, et al. Prevalence and antibiogram pattern of Pseudomonas aeruginosa in a tertiary care hospital from Odisha, India. Trans World Med J ISSN 20141;(3):77­80.
  24. Mangaiarkkarasi A, Meher Ali R, Gopal R. Bacteriological profile of gram negative organisms and drug sensitivity pattern of escherichia coli in hospital specimens. Int J Recent Sci Res 2013;4,(5):572-5.
  25. Oteo J, J Campos, F Baquero. Antibiotic resistant in 1962 invasive isolates of Escherichia coli in 27 Spanish hospitals participating in the participating in the european antimicrobial resistance surveillance system. J Antimicrob Chemother 2002;50:945-52.
  26. Maksum Radji, Rafika Fathni, Siti Fauziyah. Evaluation of surgical antibiotic prophylaxis in tertiary care hospital in jakarta indonesia. Experi J 2014;18(4):1292-6.
  27. Vera Vlahović-Palčevski, Igor Francetić, Goran Palčevski, Srđan Novak, Maja Abram, Ulf Bergman. Antimicrobial use at a university hospital: appropriate or misused? A qualitative study. Int J Clin Pharmacol Ther 2007;45(3):169-74.
  28. R Shyamala, Janardhan Rao. The Incidence of uropathogens and their resistance pattern in a tertiary care hospital. Scholars Res Library-Der Pharm Let 2013;5(1):316-7.
  29. Nathisuwan S, Burgess DS, Lewis JS 2nd. Extended spectrum β-lactamases: epidemiology, detection and treatment. Pharmacother 2001;21:920–8.
  30. Muhammad Naeem, Mussharaf A Khan, Sajid M Qazi. Antibiotic susceptibility pattern of bacterial pathogens causing urinary tract infection in a tertiary care hospital. Ann Pak Inst Med Sci 2010;6(4):214-8.
  31. Hasan AS, Nair D, Kaur J, Baweja G, Deb M, Aggarwal P. Resistance patterns of urinary isolates in a tertiary Indian hospital. J Ayub Med Coll Abbottabad 2007;19:39-41.
  32. Saghir S, Faiz M, Saleem M, Younus A, Aziz H. Characterization and anti-microbial susceptibility of gram-negative bacteria isolated from bloodstream infections of cancer patients on chemotherapy in Pakistan. Indian J Med Microbiol 2009;27:341-7.
  33. Gaurav Dalela, Sweta Gupta, Dinesh Kumar Jain, Pushpa Mehta. Antibiotic resistance patterns in uropathogens at a tertiary care hospital at Jhalawar with special reference to ESBL, AmpC b-lactamase and MRSA production. J Clin Diagn Res 2012;6(4):645–51.
  34. Syed Mustaq Ahmed, Ramakrishna Pai Jakribettu, Shaniya koyakutty, Arya B, Shakir VPA. An overview on the prevalence and the anti-biogram of gram negative uropathogens in a tertiary care centre in north kerala. India J Clin Diagn Res 2012;4602:2355.
  35. Bonten M, Stobberiug E, Phillips J, Houben A. High prevalence of antibiotic reisistnt Escherichia coli in fecal samples of students in Southeast of The Netherlands. J Antimicrob Chemother 1990;26(4):585–92.
  36. Mutate AJ, Hak E, Schurink CA. Resistance of uropathogens in symptomatic urinary tract infections in Leon, Nicaragua. Int J Antimicrob Agents 2004;23(5):506-9.
  37. M Mehdinejad, AD Khosravi, A Morvaridi. Study of prevalence and antimicrobial susceptibility pattern of bacteria isolated from blood cultures. J Biol Sci 2009;9(3):249-53.
  38. Hu S, Liu X, Peng Y. Assessment of antibiotic prescription in hospitalised patients at a Chinese university hospital. J Infect 2003;46(3):161-3.
  39. Ansari F. Use of systemic anti-infective agents in Iran during 1997-8. Eur J Clin Pharmacol 2001;57:547–51. 
  40. Maksum Radji, Siti Fauziah, Nurgani Aribinuko. Antibiotic sensitivity pattern of bacterial pathogens in the intensive care unit of Fatmawati Hospital, Indonesia. Asian Pac J Trop Biomed 2011;39-42.
  41. Baktygul Kambaralieva, Marat B, Ashirali Z, Harun-Or-rashid M, Sakamoto J. An assessment of antibiotics prescribed at the secondary health-care level in the Kyrgyz Republic. Nagoya J Med Sci 2011;73(3-4):157-68.
  42. Mathai D, Rhomberg PR, Biedenbach DJ, Jones RN. India Antimicrobial Resistance Study Group. Evaluation of the in vitro activity of six broad-spectrum beta-lactam antimicrobial agents tested against recent clinical isolates from India: a survey of ten medical center laboratories. Diagn Microbiol Infect Dis 2002;44(4):367-77.