Research Article - (2018) Volume 9, Issue 1

A Follow up Study of Bacteriology and Antibiotic Sensitivity Pattern of Urinary Tract Infection in a Tertiary Care Hospital in Bangladesh

MI Majumder1*, T Ahmed2, N Sakib3, AR Khan4 and CK Saha5
1Department of Medicine, Professor and Head, Comilla Medical College, Bangladesh
2Department of Medicine, Professor, Comilla Medical College, Bangladesh
3Department of Medicine, Project Coordinator, CIPRB, Dhaka, Bangladesh
4Department of Medicine, Assistant Professor, Comilla Medical College, Bangladesh
5Department of Medicine, Assistant Professor, Comilla Medical College, Bangladesh
*Corresponding Author: Md MI Majumder, Professor and Head, Department of Medicine, Comilla Medical College, Bangladesh Email:

Abstract

Background: Urinary tract infections (UTIs) are a common infection. The aim of this follow up study is to see the changing trends in bacteriology and antibiotic sensitivity pattern among uropathogens in comparison to similar study 5 years back.
Materials and methods: We performed a prospective study in Comilla medical college hospital, Bangladesh during the period of July 2015-June 2016. Urine samples from 658 suspected UTI patients aged above 12 years inoculated for semiquantitative urine culture and sensitivity test. Antibiotic susceptibility pattern was done by Kirby- Bauer disc diffusion method following clinical laboratory science (CLS) program.
Results: Culture passivity were in 198 samples among 658 inoculated samples. E. coli was isolated from 171(86%) samples which was the most predominant bacteria followed by Klebsiella and Enterococcus. UTI with E. coli was significantly increased in the year 2016 in comparison to 2011. Meropenem, imipenem, amikacin, tazobactum, gentamycin nitrofurantoin, and mecillinum, found sensitive against 88% to100% of the uropathogens. Bacteria offered high degree of resistance against commonly used antibiotics-amoxycillin, amoxiclav, cephradine and cefixime ranging 60% to 86%. Comparative study of 2016 vs. 2011 shows significant reduction in sensitivity for imipenum, ceftriaxone, amoxiclav and increased sensitivity for nalidexic acid, ciprofloxacin, mecillinum, colistin, cotrimoxazole.
Conclusion: UTI with E. coli was significantly increased in the year 2016. This study failed to show a steady increase in resistance to all studied antibiotics. Imipenem, meropenem, tazobactum, amikacin and nitrofurantoin still remain more sensitive in this comparative study. Comparative study of 2016 vs. 2011 shows significant increasing resistance for imipenum, ceftriaxone, amoxiclav and increasing sensitivity for nalidexic acid, ciprofloxacin, mecillinum, colistin, cotrimoxazole.

Keywords: Urinary tract infection; Follow up comparative study; Changing trends; Culture; Sensitivity; resistance

Introduction

Urinary tract infection (UTI) is a common bacterial infection in mankind and is a major public health problem in terms of morbidity and financial cost which affecting 150 million people each year worldwide [1,2]. In 2007, in the United States alone, there were an estimated 10.5 million office visits for UTI symptoms [3].

Diagnosis and treatment of UTI are empirical mostly because this is imperative to start antibiotics in almost all cases due to low socio economic status, urinary obstruction, unavailability of urine culture facilities for rural patients in Bangladesh. To initiate empirical treatment with appropriate antibiotic is necessary to have current knowledge regarding causative organisms and their antibiotic sensitivity pattern [4]. But alarming fact is that a large number of patient do not respond to conventional antimicrobial agents [5].

Antimicrobial resistance is a well-known important emerging clinical and public health problem. There are various reports available in last two decades about changing pattern of pathogen and their sensitivity pattern to routinely used antibiotics which makes the situation miserable [5], increasing antibiotic resistance among uropathogens to commonly prescribed drugs has become a global reality. Resistance occurs in intestinal bacteria due to antibiotic therapy for treating infections outside the urinary tract [6]. The irrational use of antibiotics has an influence in the spread of antimicrobial resistance among bacteria [7,8]. Controlling antimicrobial resistance is a major issue confronting organized health care today. Therefore this is warranted to know information about rapidly changing sensitivity pattern of micro-organisms towards antibiotics in UTI. To get update information for proper therapeutic interventions, periodic evaluation and regional surveillance programs is necessary for the development local data about the antimicrobial sensitivity to uropathogens for in UTI.

The present study was undertaken to observe the current bacterial uropathogens and their antibiotic sensitivity pattern in a tertiary hospital in Bangladesh to compare previous same pattern of study in 2011 [9]. It will be helpful for awareness and antibiotic use in UTI in this tertiary level hospital and country level.

Materials and Methods

It was a prospective study in department of medicine Comilla medical college hospital during the period of July 2015-June 2016. All the patients included in this study ware above 12 years of age, presented with the suspected UTI (dysuria, frequency, fever and pain in lower abdomen). The patients presented with active menstruation, PID, tubo-ovarian disease, appendicitis, colitis, epididymitis and orchitis diagnosed either clinically or by investigations were excluded from this study. Those patients were on antibiotic advised to stop drug for 48 h and were included in this study.

Freshly voided midstream clean-catch urine samples were collected from each 658 patients of different age and sex groups in a sterile screw capped universal container. The specimen was labeled and transported to the microbiology laboratory for processing and cultured within half an hour of collection. A modified semi-quantitative technique using a standard calibrated bacteriological loop of urine was performed to transfer 0.001 ml of sample on blood agar and MacConkey agar media. After allowing the urine to be absorbed into the agar, the plates were then inverted and incubated aerobically at 37°C for 24 h. The plates were then examined macroscopically for bacterial growth. The colony count was done using semi quantitative method. Number of colonies obtained was multiplied by 1000 to obtain the colony forming units (CFU)/ml [10].

A significant growth is considered if the number of colony is ≥ 105 CFU/ml. Colonial appearance and morphological characters of isolated bacteria was noted and gram staining was done for identification of the isolated organisms. The characteristic bacteria on the culture media were aseptically isolated.

Antimicrobial sensitivity tests were carried out by disc diffusion technique using Muller Hinton Agar. Interpretation of results was expressed in sensitive and resistant depending upon the size of the zone of inhibition. The antibiotics used for susceptibility testing in our study were amoxycillin, amoxyclav, cefotaxime, ceftriaxone, cephalexin, nalidexic acid, nitrofurantoin, mecillinum, amikacin, cefixime, ceftazidime cefuroxime, cephradine ciprofloxacin cotrimoxazole, gentamycin, tazobactum, meropenem, and imipenem.

Results

A total of 658 urine samples were collected from suspected UTI patients.

Base line characteristics in patients in urine culture without growth and with growth had shown in Tables 1 and 2.

  Frequency (Total – 460) Percentage
Residence
Urban 136 30
Rural 334 70
Education
Educated 303 66
Not educated 157 34
Marital status
Married 338 73
Unmarried 122 27
Sexual activity
Active 285 62
Not active 175 38
Economical status
Lower class 49 11
Middle class 393 85
Higher class 18 4
Dysuria
Present 321 68
Absent 139 32
Urgency
Present 359 78
Absent 101 22
Fever
Present 336 73
Absent 124 27
Abdominal pain
Present 354 77
Absent 106 23
Treated with antibiotics
Yes 221 48
No 239 52
Co-morbid condition
DM 55 12
HTN 15 3
ISD 8 2
Others 34 7
Pressure ulcer
Present 40 9
Absent 420 91

Table 1: Base line characteristics in patients without growth in urine culture.

  Frequency (Total- 198) Percentage
Residence
Urban 66 33
Rural 132 67
Education
Educated 134 68
Not educated 64 32
Marital status
Married 163 82
Unmarried 35 18
Sexual activity
Active 143 72
Not active 55 28
Economical status
Lower class 10 5
Middle class 180 91
Higher class 8 4
Dysuria
Present 152 77
Absent 46 23
Urgency
Present 175 88
Absent 23 12
Fever
Present 133 67
Absent 65 23
Abdominal pain
Present 150 76
Absent 48 24
Treated with antibiotics
Yes 94 48
No 104 52
Co-morbid condition 68 34
DM 45 23
HTN 27 14
IHD 4 2
Pressure ulcer
Present 22 11
Absent 176 89

Table 2: Base line characteristics in patients with growth in urine culture.

Among 198 culture positive samples, E. coli was ranked highest 171 (86%). Growth of Klebsiella pneumonia and Enterococcus was found in 17 (9.6%) and 10 (5%) samples respectively. It was also observed from this table that the maximum numbers of isolates were distributed among the females 123 (62%) (Table 3).

SL No. Bacterial Isolates Frequency
    Number (%) Male (%) Female (%)
1 E. coli 171 (86) 69 (35) 102 (51)
2 Klebsiella 17 (9.6) 4 (2) 13 (7)
3 Enterococcus 10 (5) 2 (1) 8 (4)
  Total 198 75 (38) 123 (62)

Table 3: Frequency of Isolation of organism in relation to sex of patient and their overall percentage.

Study shows, meropenem, imipenem, amikacin, tazobactum, gentamycin nitrofurantoin, and mecillinum, were found to be most effective antibiotic against most of the uropathogens. In vitro sensitivity of the isolates to these antibiotics was shown to be varied from 88% to 100%. This table also shows high degree of resistance against commonly used antibiotics-amoxycillin, amoxiclav, cephradine and cefixime Tables 4 and 5. In vitro resistance of the isolates to these antibiotics was varied from 60% to 86%.

Name of organism No (%) 2016 No (%) 2011 Chi-Square Value (x2) P. value
E. coli 171 (86) 98 (75) 3.17 <0.01
Klebsiella 17 (9.6) 14 (10.4) 0.29 >0.1
Enterococcus 10 (5) 8 (6) 0.38 >0.1
Pseudomonas 0 2(1.5) 0.16 >0.1
Proteus 0 2 (1.5) 0.16 >0.1
Staph. aureus 0 4 (3) 0.47 >0.1
E. coli & Klebsiella 0 3 (2.29) 0.35 >0.1

Table 4: Comparative study between the common isolated uropathogenic bacteria in the year 2016 and 2011. UTI with E. coli was found statistically significant increase in the year 2016 with p values <0.01.

Sl. No Name of  antibiotics Total No Sensitive Percentage
1 Meropenem 198 100
2 Imipenem 197 99.5
3 Amikacin 196 99
4 Tazobactum 196 99
5 Gentamycin 178 90
6 Nitrofurantoin 175 88
7 Mecillium 174 88
8 Colistin 167 84
9 Ceftazidime 114 53
10 Cotrimoxazole 105 53
11 Ciprofloxacin 104 52
12 Ceftriaxone 102 45
13 Nalidexic acid 89 45
14 Cephlalexine 86 43
15 Cefuroxime 84 42
16 Cefotaxime 84 42
17 Cefixime 80 40
18 Cephradine 68 34
19 Amoxiclav 49 24
20 Amoxicillin 28 14

Table 5: In vitro antibiotics sensitivity pattern of the bacteria (n=198).

There was statistically significant reduction in sensitivity pattern in year 2016 in comparison to 2011 was detected for imipenum, ceftriaxone, and amoxiclav. On the other hand significant increase in sensitivity pattern was found for nalidexic acid, ciprofloxacin, mecillinum, colistin and cotrimoxazole. No statistically significant change in sensitivity pattern was shown for other antibiotics (Table 6).

Antibiotic 2016 (n=198) 2011 (n=131) Chi-Square Value (x2) P value
Carbapenem  
Imipenem 197 (99.5%) 131 (100.0%)   0.0001
Meropenem 198 (100.0% 128 (98.0%) 0.51 0.4751
Cephalosporins  
1st Generation  
Cephradine 68 (34.0%) 48 (37.0%) 0.09 0.7642
Cephlalexine 86 (43.0%) 46 (34.7%) 1.13 0.2878
2nd Generation  
Cefotaxime 84 (42.0%) 51 (39.0%) 0.08 0.7773
Ceftazidime 114 (53.0%) - - -
Cefuroxime 84 (42.0%) 49 (37.0%) 0.33 0.5657
3rd Generation  
Ceftriaxone 102 (51.5%) 100 (76.0%) 12.08 0.0005
Cefixime 80 (40.0%) 40 (30.0%) 1.78 0.1821
Quinolones  
Nalidexic acid 89 (45.0%) 33 (25.0%) 7.93 0.0049
Ciprofloxacin 104 (52.0%) 45 (34.5%) 5.6 0.018
Aminoglycosides  
Amikacin 196 (99.0%) 128 (98.0%) 0 1.0
Gentamycin 178 (90.0%) 113 (86.0%) 0.43 0.512
Penicillin  
Amoxiclav 49 (24.0%) 100 (76.0%) 52.02 0.0001
Amoxicillin 28 (14.0%) 17 (13.0%) 0 1.0
Mecillinum 174 (88.0%) 92 (70.0%) 8.71 0.0032
Colistin 167 (84.0%) 114 (58.0%) 15.18 0.0001
Nitrofurantoin 175 (88.0%) 119 (91.0%) 0.21 0.6468
Tazobactum 196 (99.0%) - - -
Cotrimoxazole 105 (53.0%) 50 (38.0%) 3.95 0.0469

Table 6: Comparative study between 2016 and 2011 of trend of antibiotic sensitivity pattern of uropathogenic bacteria.

Discussion

This study demonstrates the distribution and antibiotic susceptibility pattern of bacteria isolated from patients with suspected UTI from a tertiary care center. The patients attending in our center with symptoms suggestive of UTI, 31% had culture positive, which was nearer to our previous study in 2011 where growth was 24% [9]. Studies by BHN Yasmeen et al. [11] on 2014 in Bangladesh shows 21% urine sample were positive for pathogenic organisms. Our study showed a high prevalence of UTI in females (73.57%) than in males (35.14%) which is similar to other reports where it was shown that the frequency of UTI is greater in females as compared to males [12-14]. It has been extensively reported that adult women have a higher prevalence of UTI than men, principally owing to anatomical and physical factors [15-17].

In this study, the most predominant isolated organism was E. coli (86%) which was significantly higher (p value was <0.01) than our previous studies in 2011 where E. coli was 75% [9].

In this study the most powerful antibiotic was meropenem, imipenem, tazobactum and amikacin. These antibiotics show their efficacy against 99-100% of the uropathogens which was similar to our previous study on 2011 [9]. Uropathogens shows higher degree of resistance against most of the antibiotics used for sensitivity. This increasing resistance is due to irrational consumption of most of the antibiotics during the past decade in our region [8,18,19]. As meropenem imipenem and tazobactum are highly expensive medicine which makes it very difficult to purchase by most of the peoples of our community. So like our previous study still our recommendation is in favor of using amikacin regarding empirical antibiotics in UTI. The most sensitive oral antibiotics were nitrofurantoin. It shoes its effectiveness against 88% of the isolates. This drug exhibited low resistance rate in the major part of the world (0–5.4%), despite of its use for many years which was because of localized action of this drug only on the urinary tract [20]. So, nitrofurantoin can be considered as first line, cost saving and effective oral therapy in UTI. There was significant reduction in sensitivity pattern in year 2016 was detected for imipenum, ceftriaxone, and amoxiclav, possibly because random use of these antibiotics in past few years with inadequate dose and duration. Uropathogens resistance to antibiotic has now become a public health concern in Bangladesh [21]. There was significant increase in sensitivity pattern in year 2016 was detected for Nalidexic acid, Mecillinum and Colistin because these antibiotics are not commonly used in our community in last few years. According to guideline by Infectious Diseases Society of America (IDSA) in the year 2011, an antibiotic is no longer recommended for empirical treatment of acute UTI if there is >20% resistance prevalence to that particular antibiotic [22]. According to this guideline of IDSA, most of the antibiotics used in our study should not be used for empirical treatment of acute UTI and our standard treatment guidelines for UTI is not sufficient which requires a large scale study.

There is urgent need of constant monitoring with culture and sensitivity pattern of specific pathogens in different health care centre’s in our country. Community awareness program should be undertaken for adherence to treatment protocol considering bacterial resistance and emerging multidrug resistant strains. It is necessary to conduct a regional research on the culture and sensitivity patterns of the bacteria. All the authors contributed equally in this study.

Conclusion

UTI with E. coli was significantly increased in the year 2016. This study failed to show a steady increase in resistance to all studied antibiotics. Imipenem, meropenem, tazobactum, amikacin and nitrofurantoin still remain more sensitive in this comparative study. Comparative study of 2016 vs. 2011 shows significant increasing resistance for imipenum, ceftriaxone, amoxiclav and increasing sensitivity for nalidexic acid, ciprofloxacin, mecillinum, colistin, cotrimoxazole.

References

Citation: Majumder MI, Ahmed T, Sakib N, Khan AR, Saha CK (2018) A Follow up Study of Bacteriology and Antibiotic Sensitivity Pattern of Urinary Tract Infection in a Tertiary Care Hospital in Bangladesh. J Bacteriol Parasitol 9: 334.

Copyright: © 2018 Majumder MI, et al. This is an open-access article distributed under the terms of the creative commons attribution license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.