|Year : 2012 | Volume
| Issue : 2 | Page : 79-82
Bacteriological profile of cholectystitis and their implication in causing post-operative wound infections
H Pushpalatha1, Rudresh M Shoorashetty2
1 Department of Microbiology, Vijayanagar Institute of Medical Sciences, Cantonment, Bellary, Karnataka, India
2 Bidar Institute of Medical Sciences, Bidar, Karnataka, India
|Date of Web Publication||3-Apr-2013|
Rudresh M Shoorashetty
Department of Microbiology, Bidar Institute of Medical Sciences, Bidar - 585 401, Karnataka
Source of Support: None, Conflict of Interest: None
Background: Cholecystitis is a common indication for major abdominal surgeries. It may occur with or without obstruction of common bile duct. Obstruction leads to secondary bacterial infection of bile. Bactibilia is an important predisposing factor for post-operative complications. Hence, this study was designed to determine the prevalence of bacteria in bile samples of cholecystitis patients and to correlate bactibilia and post-operative wound infection.
Materials and Methods: Bile samples collected intra-operatively were subjected to gram stain, culture, and antibiotic sensitivity testing. The patients were followed-up for post-operative complications. If post-operative wound infection was found, cultures were done and correlated with bacteria isolated from bile samples.
Results: Bactibilia was found in 27/50 (52%) of patients. Polymicrobial flora was found in 10% of bile samples. Escherichia coli, Klebsiella pneumoniae and Enterococcus faecalis were the predominant organisms isolated. None of the anaerobes were isolated. Extended spectrum β-lactamase and AmpC β-lactamase (AmpC) production was seen in 47% and 31.5% of Enterobacteriaceae isolates respectively. Post-operative wound infection was found in six (12%) patients who had bactibilia. Combination of piperacillin-tazobactam and amikacin was most effective in prophylactic regimen.
Conclusion: The organisms responsible for bactibilia were found to cause post-operative infections in the same patient warranting the use of prophylactic antibiotics in every patient undergoing cholecystectomy. All patients undergoing open cholecystectomy should receive prophylactic antibiotics to prevent post-operative wound infections.
Keywords: Antibiotic prophylaxis, bactibilia, cholecystectomy, cholelithiasis
|How to cite this article:|
Pushpalatha H, Shoorashetty RM. Bacteriological profile of cholectystitis and their implication in causing post-operative wound infections. Arch Int Surg 2012;2:79-82
|How to cite this URL:|
Pushpalatha H, Shoorashetty RM. Bacteriological profile of cholectystitis and their implication in causing post-operative wound infections. Arch Int Surg [serial online] 2012 [cited 2020 Feb 20];2:79-82. Available from: http://www.archintsurg.org/text.asp?2012/2/2/79/110028
| Introduction|| |
Cholecystitis is the inflammation of the gallbladder, which may be acute, chronic, calculous, or acalculous. It is usually secondary to stone, neoplasm or benign strictures in the cystic duct or in the common bile duct. It has become the most common indication for major abdominal surgeries like cholecystectomy, choledochotomy and explorative surgeries of common bile duct.  Open cholecystectomy has a mortality and morbidity rates of 0.2-1.5% and 5.0-15% respectively.  Emergency cholecystectomy for acute cholecystitis has mortality of 0.8-2%. 
Presence of bacteria in gallbladder bile is called bactibilia. , Etiologic role of aerobic and anaerobic bacteria in gallbladder disease has been proposed but their pathogenic role is not well established. Most common aerobic organisms associated with cholecystitis are Escherichia More Details coli, Klebsiella species and Enterococcus faecalis, which constitute the normal intestinal flora. Bacteroides and Clostridium are the predominant anaerobic organisms seen, especially in elderly patients. 
Bactibilia is an important predisposing factor in post-operative septic complications like gram negative septicemia, post-operative wound infections, post-operative cholangitis, respiratory and urinary tract infections.  Studies have found post-operative wound infections following open cholecystectomy to be 2.3%. 
Hence present study was undertaken to look for bacteriological profile of bile samples from cases of cholecystitis and to know about their antibiotic susceptibility pattern. The study also correlated the presence of bacteria in the biliary tract and their implication in causing post-operative wound infection.
| Materials and Methods|| |
This prospective study was conducted in 50 cholecystitis patients undergoing elective open cholecystectomy, choledocholithotomy or explorative common bile duct surgeries. Patients of all age groups were included in the study. The study was conducted for a period of 13 months. Data on microbial profile, therapy, and post-operative outcomes were analyzed.
During surgery gallbladder contents were aseptically aspirated using sterile syringe. The needle tip of syringe was sealed with sterile rubber cork and was sent to Microbiology laboratory within 30 min.
Immediately samples were inoculated into brain heart infusion (BHI) broth and Robertson's cooked meat (RCM) medium. Sterile paraffin oil was overlaid on RCM medium. Bile was subjected to gram stain and was examined for pus cells and microorganisms. BHI broth and RCM were incubated at 37°C. If there is any turbidity in BHI broth it was sub-cultured on to 5% sheep blood agar and MacConkey agar medium, incubated at 37°C for 18-24 h in ambient air. Any growth was identified by standard laboratory methods. Antibiotic susceptibility testing was done according to Clinical Laboratory Standards Institute (CLSI) recommended Kirby-Bauer disk diffusion testing. BHI broths which remained clear till 7 th day of incubation were sub-cultured and if no growth was observed then they were considered sterile. Extended spectrum beta-lactamase (ESBL) detection was done according to CLSI recommended disk potentiation test.  AmpC β-lactamase detection was done by modified three dimensional test. Quality control was performed by testing E. coli American Type Culture Collection (ATCC) 25922.
Any turbidity in RCM was sub-cultured onto neomycin blood agar with metronidazole and gentamicin disks and incubated in anaerobic jar with gas pack for 48 h at 37°C. Plates showing no growth were re-incubated for an additional period of 5 days. Isolates were identified by standard laboratory methods.
Patients who develop post-operative wound infections were further investigated by doing appropriate cultures and other investigations.
Ethical clearance for the study was obtained from Institutional Ethical Committee.
Data was analyzed using SPSS version 17.0 software. Descriptive frequencies were calculated and Chi-square was used to find P value. P value < 0.05 was considered as statistically significant.
| Results|| |
A total of 50 patients with cholecystitis undergoing surgery were studied. Among the 50 patients, 31 (62%) were females and 19 (38%) were males (ratio 1.6:1). The mean age was 45 years ± 15 years. Common bile duct stone was detected in 28 patients, gallstones in 12, neoplasm in six and common bile duct stricture in four.
Aerobic culture of bile samples yielded growth in 27/50 (52%) cases. None of the anaerobes were isolated. Bactibilia was found in 10/28 patients of common bile duct obstruction, 8/12 gallstones, 5/6 neoplasms and 4/4 cases of common bile duct stricture. Polymicrobial flora was seen in five (10%) samples and E. coli (n = 13), Klebsiella pneumoniae (n = 6) and E. faecalis (n = 5) were the predominant organisms isolated. Two samples grew Candida albicans [Table 1].
E. coli and K. pneumoniae showed high level of resistance to third and fourth generation cephalosporins [Table 2]. Both the organisms were sensitive to chloramphinicol, piperacillin-tazobactam and Amikacin. ESBL and AmpC production was seen in 47% and 31.5% of Enterobacteriaceae isolates respectively. Imipenem and meropenem were effective against these organisms. An isolate of K. pneumoniae which was imipenem resistant, was found to be carbapenemase producer in modified Hodge test. Pseudomonas aeruginosa showed 100% sensitivity to amikacin and cefepime, but was resistant to all other antibiotic including, carbapenems.
|Table 2: Antibiotic sensitivity pattern of organisms isolated from bactibilia|
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Among the gram positive organisms Staphylococcus aureus and E. faecalis were 100% sensitive to vancomycin and linezolid. Methicillin resistance (25%), inducible clindamycin resistance (25%) and constitutive clindamycin resistance (25%) was found among S. aureus isolates.
Post-operative wound infection was found in six (12%) patients who had bactibilia. Pus samples from all the six cases grew organisms which were similar to the organisms in the bile cultures from the same patients (from bile samples of the same patients). Four cases had post-operative infection with E. coli and Klebsiella species in mixture. One case was infected by Methicillin Resistant Staphylococcus aureus (MRSA) and another with P. aeruginosa. The other post-operative infections noted in patients with bactibilia were two cases of urinary tract infection and one case of respiratory infections. All the patients with sterile bile cultures did not suffer from post-operative wound infection.
| Discussion|| |
Bile in individuals with normal biliary tract is sterile. Presence of biliary obstruction leads to bacterial colonization of bile. Ascending infection from duodenum or bacterial translocation from portal vein are the likely sources of infection. In the present study, the most common organisms isolated from bile samples were E. coli, K. pneumoniae and E. faecalis. The prevalence of bactibilia was found to be 52% and this is similar to that published elsewhere. ,
Post-operative wound infection was found in 12% of patients who had bactibilia (P < 0.005). Patients with sterile bile cultures did not develop any post-operative infections. Isolates obtained from post-operative wound samples were identical (biochemical reactions and anti-biogram) to those obtained from bile samples suggesting endogenous origin of infection. Hence the study recommends bile cultures in all patients undergoing cholecystectomy. In contrary, Velαzquez-Mendoza et al. in their study did not find any significant differences in post-operative complications between groups with positive and negative bile cultures. The reasons for such findings may be due to the small sample size.
The present study shows that piperacillin-tazobactam and amikacin are highly effective against aerobic organisms. When these antibiotics are used in combination they can cover both gram positive and gram negative organisms. Many studies recommend, if gram positive bacilli are seen in gram stain of bile sample, then penicillin should be added to the regime.  Prophylactic antibiotics should be continued 5-7 days post-operatively. Choudhary, et al. in their study, showed that the use of prophylactic antibiotics neither prevented infection nor decreased length of hospital stay. However, Chandrashekhar, et al. in a prospective study found a lower rate (3%) of post-operative wound infections among the patients who received prophylactic antibiotics when compared to those who did not receive (23%).
The increased incidence of post-operative infection among patients having bactibilia warrants the use of prophylactic antibiotics. The empirical antibiotics should cover both gram positive and gram negative organisms. Although, cephalosporins are considered to be effective for prophylaxis in biliary disease, raising incidence of ESBL and AmpC warrants use of alternative antibiotics.
| Conclusion|| |
Aerobic organisms are most commonly isolated from bile samples. The organisms responsible for bactibilia were found to cause post-operative infections in the same patient warranting the use of prophylactic antibiotics in every patient undergoing cholecystectomy. Increased incidence of ESBL and AmpC among the isolates of bactibilia demands appropriate use of antibiotics in clinical practice.
| References|| |
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[Table 1], [Table 2]