scholarly journals Direct susceptibility testing by disk diffusion on positive BacT/ALERT blood cultures: A rapid and definite tool for antibiotic stewardship

Author(s):  
Sandhya Bhat K ◽  
V Lokeshwari

Blood stream infections continue to be the major cause of mortality and morbidity and hence early availability of direct susceptibility reports can be lifesaving. This study aims to ascertain if direct susceptibility testing (DST) can be used as a diagnostic tool in bacteremic patients and to correlate the results of both DST and standard antimicrobial susceptibility reports (AST), thereby serving to benefit both the patients and also to reduce the irrational use of antibiotics. An experimental study was carried out after obtaining waiver of consent, in a tertiary care centre. A total of 37 patients were included in the study after careful consideration of the inclusion and exclusion criteria. Gram staining report, bacteriological profile, direct susceptibility report, antimicrobial susceptibility report of all the isolates were documented. Statistical analysis was done by using IBM SPSS software. Overall prevalence of sepsis was 40.5%. Gram negative bacteria were more commonly isolated (83.8) and Escherichia coli was the commonest isolate (51.4%). The antimicrobial resistance was observed maximum for amoxicillin/clavulanic acid (66.7%), ceftriaxone (60.6%), Cefotaxime (57.6%) and least for meropenem (9.1%), imipenem (6.1%). On comparison of DST with AST among 28 gram-negative Enterobacteriaceae isolates 15 minor errors (4.8%) and three major errors (0.97%) were recorded, with maximum errors being documented for piperacillin/tazobactam with five minor errors (17.9%) and one major error (3.6%). DST is an important tool for early institution of targeted therapy and should be considered as one of the step towards antibiotic stewardship intervention.

2021 ◽  
pp. 004947552097929
Author(s):  
Tarana Sarwat ◽  
Mariyah Yousuf ◽  
Ambreen S Khan ◽  
Dalip K Kakru ◽  
Renu Dutta

Non-fermenting Gram-negative bacilli (NFGNB) are emerging as important cause of blood stream infections. We aimed to determine the prevalence and antibiotic susceptibility pattern of NFGNB isolated from blood of patients with sepsis. We found, in 176 patients, the most common to be Pseudomonas aeruginosa (74) and Acinetobacter baumanii complex (39) followed by Stenotrophomonas maltophilia (16), Sphingomonas paucimobilis (6), Burkholderia cepacia (5) and Ochrobactrum anthropic (1). Generally, organisms showed a good sensitivity towards colistin, carbapenems and fluoroquinolones, whereas cephalosporins were ineffective.


Author(s):  
Kavipriya D. ◽  
Suman Susan Prakash ◽  
Sarumathi Dhandapani ◽  
Deepashree Rajshekar ◽  
Apurba Sankar Sastry

Abstract Background Timely initiation of antimicrobial therapy in patients with blood stream infection is absolutely necessary to reduce mortality and morbidity. Most clinical microbiology laboratories use conventional methods for identification and antimicrobial susceptibility testing (AST) that involve biochemical methods for identification followed by AST by disk diffusion. The aim of the current study is to assess the various errors associated with direct susceptibility testing done from blood culture broth using automated AST system-Vitek-2 compact compared with the reference method of AST done from bacterial colonies. Materials and Methods The study was conducted in a tertiary care public sector 2,200-bedded hospital in South India for a period of 6 months. The study involved positively flagged blood culture bottles that yielded single morphotype of Gram-negative organism by Gram stain. A total of 120 bacterial isolates were collected that consisted of consecutively obtained first 60 isolates of Enterobacteriaceae family (30 Escherichia coli and 30 Klebsiella pneumoniae) and consecutively obtained first 60 nonfermenters (30 Pseudomonas aeruginosa and 30 Acinetobacter baumannii). Vitek-2 AST was done from these 120 blood culture broth, following the protocol by Biomerieux, and results were obtained. Then, Vitek-2 was done from colonies (reference method) using appropriate panel for Enterobacteriaceae and nonfermenters, and results were obtained. Both the results were compared. Results Nonfermenters showed a better categorical agreement of 97.6%, as compared to Enterobacteriaceae, which showed 97%. Among Enterobacteriaceae, both E. coli and K. pneumoniae showed categorical agreement of 97% each. Conclusion The procedure of AST directly from blood culture broth represents a simple and effective technique that can reduce the turnaround time by 24 hours, which in turn benefits the clinician in appropriate utilization of antimicrobials for better patient care.


2021 ◽  
Vol 8 (8) ◽  
pp. 429-434
Author(s):  
Atit Dineshchandra Shah ◽  
Urvashi Natubhai Limbachia ◽  
Bhavin K. Prajapati ◽  
Lata Patel ◽  
Dharati Tusharbhai Shah ◽  
...  

BACKGROUND Non fermenting gram-negative bacilli (NFGNB) are a group of heterogenous, aerobic and non-sporing saprophytic bacteria, found as commensals in humans and other animals primarily causing opportunistic healthcare-associated infections. They are innately resistant to many antibiotics and are known to acquire resistance by various mechanisms. They pose a particular difficulty for the healthcare community because multidrug resistance is common and increasing among them and a number of strains have now been identified that exhibit pan drug resistance. This study was conducted to isolate and identify various non-fermenter gram negative bacilli (NFGNB), to study their antibiotic sensitivity pattern and their clinical significance from various clinical samples. METHODS A study was undertaken from March 2019 to February 2020 to isolate NFGNB from various clinical samples received for culture and sensitivity in the department of microbiology in a tertiary care hospital, Ahmedabad. Non lactose fermenting colonies on MacConkey agar plates were further processed by Vitek 2 to identify them and to study their antimicrobial susceptibility testing (AST). RESULTS A total of 2010 NFGNB were isolated from various clinical samples and their AST was evaluated by Vitek 2. Pseudomonas aeruginosa (52.7 %) and Acinetobacter baumannii (36.5 %) were the most common NFGNB isolated. Carbapenem resistance was 93 % for Acinetobacter species and 61 % for Pseudomonas species. CONCLUSIONS Accurate and rapid identification and antimicrobial susceptibility testing of NFGNB help in early initiation of appropriate antimicrobial therapy and proper management of patients thereby help in reducing emergence of MDR strains of NFGNB, mortality and overall hospital stay. KEYWORDS NFGNB – Non-Fermenting Gram-Negative Bacilli, Multidrug Resistance, Pan Drug Resistance, Carbapenem Resistance


Author(s):  
Gunturu Sowjanya ◽  
Pennagaram Sarguna

Introduction: Diphtheria is a vaccine preventable communicable acute infectious disease of upper respiratory tract caused by Corynebacterium diphtheriae (C. diphtheria) which is endemic in India. Delayed diagnosis of the disease leads to spread of infection in the community and causes increased morbidity and mortality in the affected individuals. To reduce the delay, an early attempt for microbiological diagnosis of diphtheria should be done as it is crucial and complimentary to clinical diagnosis. Aim: To know the prevalent toxin producing biotypes of Corynebacterium among the clinically probable cases of diphtheria. Materials and Methods: Throat swab samples from 300 clinical cases of diphtheria were processed by direct microscopy and culture. Microscopic examination was done by direct throat swab and samples were inoculated in Loeffler’s Serum Slope (LSS). Antimicrobial susceptibility testing was done by Kirby-Bauer disc diffusion method. Results were analysed using MS Excel. Results: Out of 300 samples, presumptive diagnosis of diphtheria by microscopic examination of direct throat swab was 3% and swab inoculated in LSS was 10%. Confirmed cases of diphtheria by culture were 48 (16%). A 100% sensitivity was seen for all antibiotics tested for all 48 isolates in antimicrobial susceptibility testing. Conclusion: A shift in the age wise incidence of the disease from pre-school to school age has been observed with more cases reported. C. diphtheriae gravis was the highly prevalent strain isolated. Culture should be considered as confirmatory method for diagnosis.


2019 ◽  
Vol 2 (3) ◽  
pp. 72-75 ◽  
Author(s):  
M Gajdács

Purpose Pantoea species are pigmented, Gram-negative rods belonging to the Enterobacterales order. They are considered rare, opportunistic pathogens and are mostly implicated in nosocomial outbreaks affecting neonates and immunocompromised patients. The aim of this study was to describe the prevalence and antibiotic susceptibility of Pantoea species during a 12-year period. Materials and methods This retrospective study was carried out using microbiological data collected between January 1, 2006 and December 31, 2017. Patients’ data such as age, sex, inpatient/outpatient status, and empiric antibiotic therapy were also collected. Antimicrobial susceptibility testing was performed using E-tests; the interpretation was based on European Committee on Antimicrobial Susceptibility Testing breakpoints for Enterobacterales. Results Seventy individual Pantoea spp. isolates were identified; the most frequently isolated species was Pantoea agglomerans. Most isolates were susceptible to relevant antibiotics. In 61 out of 68 patients, ampicillin was the empirically administered antibiotic. The highest levels of resistance were to amoxicillin–clavulanic acid and ampicillin. No extended spectrum beta-lactamase-positive isolate was detected. Conclusions There is a scarcity of data available on the susceptibility patterns of Pantoea species, but our results correspond to what we could find in the literature. The development of multidrug-resistant (MDR) Gram-negative bacteria is a grave concern, and the development of MDR Pantoea spp. may be expected in the future.


2009 ◽  
Vol 4 (01) ◽  
pp. 055-057 ◽  
Author(s):  
Neelam Kaistha ◽  
Manjula Mehta ◽  
Nidhi Singla ◽  
Ritu Garg ◽  
Jagdish Chander

Background: Septicemia continues to be a major cause of neonatal mortality and morbidity worldwide. Methodology: To know the rate of neonatal septicemia in our tertiary care centre, a retrospective analysis of 2,247 blood samples was done over a period of four years and three months (July 2003 to October 2007). Results: During that period, a total of 296 (13.17%) blood samples were found to be positive for bacterial isolates. Gram-negative septicemia (80.40%) was identified in more cases than Gram-positive septicemia (20.60%) with Klebsiella species 84 (28.3%) being the most common isolate. Maximum resistance among Gram-negative organisms was seen in amoxycillin/ampicillin and third-generation cephalosporins. Amikacin, cefoperazone/sulbactam and imipenem were found to be good alternative drugs.  Among Gram-positive organisms, all strains were sensitive to Vancomycin. Conclusion: Continued surveillance for various pathogens and their susceptibility profile should be done to effectively and timely treat the patients of neonatal septicaemia.


Author(s):  
Ashish Jitendranath ◽  
Radhika Rajan ◽  
lvy Viswamohanan ◽  
Ramla Beevi ◽  
Ramani Bai J T

have long been recognised as low virulence bacteria occurring as commensals in the human intestine. However in the last two decades they emerged as one of the leading causes of nosocomial infections with the development of resistance to antibiotics. So appropriate identification and characterization and antimicrobial susceptibility testing of Enterococcal species is necessary for management and prevention of these infections.150 isolates of Enterococcal species were obtained from various clinical samples. Characterisation was done by standard Microbiological methods and antibiotic susceptibility testing was done by Kirby- Bauer disc diffusion method and Vancomycin MIC tested by E- test.Out of 150 isolates from various clinical samples like urine 93(62%), pus 45(30%), blood 7(4.6%) and other body fluids 5(3%), 131(87.3%) was the predominant isolate followed by 14(9.3%), 2(1.3%), 2(1.3%) and 1(0.6%). All isolates were sensitive to Vancomycin, Teicoplanin and Linezolid. Sensitivity to High level Gentamicin was 92%. Rate of resistance to Penicillin 150(100%), Tetracycline 95(63.3%), Ciprofloxacin 103(68.6%) and Ampicillin 67(44.6%).Even though no Vancomycin resistant strains were isolated from our study, there is incidence of Vancomycin resistant are emerging as potent pathogen. So methods for characterization, antimicrobial susceptibility testing and MIC of Vancomycin should be done routinely for Enterococcal species.


KYAMC Journal ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 153-160
Author(s):  
Tanjida Shilpi ◽  
Md Arifur Rahman ◽  
Sabera Sultana ◽  
Shafinaz Khan ◽  
Sunil Krishna Baul

Introduction: Nosocomial infections have been described as an important issue among intubated patients which leads to significant morbidity and mortality. The pattern of microbiological colonization and antibiotic resistance are much valuable in this regard. Objectives: The aim of present study was to determine the pattern of aerobic bacteria isolated from endotracheal tubes in adult patients and determination of their antimicrobial susceptibility patterns. Materials and Methods: Specimens were collected from tracheal tubes of patients with endotracheal aspiration and microbiological investigations were done. The isolated bacteria were identified by using standard cultural and biochemical tests. Then antibiotic susceptibility testing was performed on the isolates by disc diffusion method according to clinical and laboratory Standards Institute (CLSI) guideline. Results: Among 104 participants 68 (65.4%) were female and 36 (34.6%) were male. Most of the patients were in the age group of 71-80 years (48.0%). From 104 positive growths, both Gram positive and Gram negative organisms were found. Maximum samples showed growth of gram negative organism. Antimicrobial susceptibility testing revealed that the most resistant Gram negative isolate was Klebsiella with highest resistance against Vancomycin (40.4%) and which showed highest sensitive against Cefotetan, Cefoxitin and Norfloxain (39.4%). Conclusions: It may be concluded that this study indicates the emergence of antibiotic resistant infections in the studied hospital. So, there is a need to improve the effectiveness of integrated infection control programs to control and manage nosocomial infections caused by highly resistant organisms. KYAMC Journal. 2021;12(3): 153-160


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