scholarly journals Incidence of Diphtheria among Clinically Probable Cases in a Tertiary Care Centre- A Prospective Study

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.

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.


2021 ◽  
Vol 12 ◽  
Author(s):  
Min Cao ◽  
Lin Huang ◽  
Yanyan Hu ◽  
Yinfei Fang ◽  
Rong Zhang ◽  
...  

Bloodstream infections (BSI) are associated with high morbidity and mortality and remain a leading cause of death. Blood culture (BC) including the identification and the antimicrobial susceptibility testing of the causative microorganisms should be performed as soon as possible. In this study, we developed an in-house rapid antimicrobial susceptibility testing (rAST) protocol for positive BC. First, the rAST was performed in the simulated positive BC of standard strains (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, and Pseudomonas aeruginosa ATCC 27853) at three different times to assess the reproducibility and operability by dispensing four drops of BC broth onto a Mueller–Hinton agar plate after a positive signal. Furthermore, the rAST was performed in clinical positive BCs. The results of rAST at 4, 6, 8, and 18 h of incubation were compared with results of the standard 16- to 20-h disk diffusion method, and the preliminary breakpoints of the rAST method were established according to the inhibition diameter of sensitive strains and resistant strains. Finally, the rAST was performed in the simulated positive BC of clinical strains to evaluate the availability of the preliminary breakpoints. The rAST results of standard strains were distributed evenly at three different times. Among the 202 clinical strains used to establish the preliminary breakpoints, the number of zone diameters that could be read and interpreted (60, 87, 98, and 100%) increased with incubation time (4, 6, 8, and 18 h), and the categorical agreement was acceptable, with total error rates of 3.0, 2.3, 2.1, and 1.3% at 4, 6, 8, and 18 h of incubation, respectively. In conclusion, the in-house rAST protocol for positive BC can be implemented in routine laboratories. It provides reliable antimicrobial susceptibility testing results for BSI pathogens after 4–6 h of incubation.


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


Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3449
Author(s):  
Cristina-Mirabela Gaşpar ◽  
Ludovic Toma Cziszter ◽  
Cristian Florin Lăzărescu ◽  
Ioan Ţibru ◽  
Marius Pentea ◽  
...  

This study aimed to compare the antibiotic resistance levels of the indicator bacteria Escherichia coli in wastewater samples collected from two hospitals and two urban communities. Antimicrobial susceptibility testing was performed on 81 E. coli isolates (47 from hospitals and 34 from communities) using the disc diffusion method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) methodology. Ten antibiotics from nine different classes were chosen. The strains isolated from the community wastewater, compared to those from the hospital wastewater, were not resistant to gentamicin (p = 0.03), but they showed a significantly higher susceptibility—increased exposure to ceftazidime (p = 0.001). Multidrug resistance was observed in 85.11% of the hospital wastewater isolates and 73.53% of the community isolates (p > 0.05). The frequency of the presumed carbapenemase-producing E. coli was higher among the community isolates (76.47% compared to 68.09%) (p > 0.05), whereas the frequency of the presumed extended-spectrum beta-lactamase (ESBL)-producing E. coli was higher among the hospital isolates (21.28% compared to 5.88%) (p > 0.05). The antibiotic resistance rates were high in both the hospital and community wastewaters, with very few significant differences between them, so the community outlet might be a source of resistant bacteria that is at least as important as the well-recognised hospitals.


2010 ◽  
Vol 10 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Maida Šiširak ◽  
Amra Zvizdić ◽  
Mirsada Hukić

Postoperative wound infections represent about 16% of hospital-acquired infections. Staphylococcus aureus is the most common cause of nosocomial wound infections. Increased frequency of Methicillin-re- sistant Staphylococcus aureus (MRSA) in hospitalized patients and possibility of vancomycin resistance requires permanent control of MRSA spread in the hospital.The purpose of this study was to analyse the frequency of Methicillin-resistant Staphylococcus aureus (MRSA) in the swabs taken from the surgical wounds, the presence of MRSA infection in surgical departments and to examine antimicrobial susceptibility of MRSA isolates.Wound swabs were examined from January 2006 to December 2008. The isolates were identified by conventional methods. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc-diffusion method as per NCCLS guidelines.A total of 5755 wound swabs were examined: 938 (16,3%) swabs were sterile and 4817 (83,7%) were positive. Staphylococcus aureus was isolated in 1050 (22,0%) swabs and it was the most common cause of wound infections. MRSA was isolated from 12,4% samples in 2006, from 6,7% samples in 2007 and from 3,7% samples during 2008. Wound infections caused by MRSA dominated in the department of plastic surgery (24,4%) and in the department of orthopaedic surgery (24,1%). Antimicrobial susceptibility testing showed that 73% of MRSA isolates were with the same antibiotic sensitivity pattern (antibiotyp)- sensitive only to vancomycin, tetracycline, fucid acid and trimethoprim/sulfamethoxasole.Our results show decreasing of MRSA infection in the surgical wards. These results appear to be maintained with strategies for preventing nosocomial infection: permanent education, strong application of protocols and urging the implementation of strict infection control policy.


2020 ◽  
Vol 7 (1) ◽  
pp. e04-e04
Author(s):  
Shirin Afhami ◽  
Mohammad Ali Borumand ◽  
Negin Esmailpour Bazzaz ◽  
Hiva Saffar ◽  
Azar Hadadi ◽  
...  

Introduction: Acinetobacter species in clinical isolates cause severe infections including meningitis, bloodstream infection, ventilator-associated pneumonia, and surgical site infections. Objectives: In the present study, we evaluated Acinetobacter drug resistance using both European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical and Laboratory Standards Institute (CLSI) antimicrobial susceptibility test methods. Materials and Methods: Clinical specimens of 128 patients who were admitted in three referral tertiary care teaching hospitals were enrolled in 2014. Blood and other sterile fluid samples, endotracheal secretion, ulcer, urine and other clinical specimen cultures were included, and microbial resistance of Acinetobacter isolates was determined and compared with disk diffusion and E-test antimicrobial susceptibility methods, using both the EUCAST and CLSI standards. Cohen’s kappa coefficient was also reported. Results: The highest percentage of resistance (96.9%) was found for meropenem and imipenem antimicrobials, and the lowest resistance (82.8%) was found for amikacin. The highest kappa agreement coefficient was for ciprofloxacin (kappa coefficient = 0.783), and the lowest kappa was for amikacin (kappa coefficient = 0.21). Conclusion: According to the results, it is better to consider amikacin as a choice in combination with another effective antimicrobial for treatment of drug resistant Acinetobacter.


2019 ◽  
Vol 13 (2) ◽  
pp. 3-6
Author(s):  
Mashrura Quraishi ◽  
Ahmed Abu Saleh ◽  
Chandan Kumar Roy ◽  
Fatima Afroz ◽  
GM Mohiuddin

The present study was undertaken to determine the antimicrobial resistance pattern of Enterobacter species to guide the clinician in selecting the best antimicrobial agent for an individual patient. A total of 50 clinical isolates of Enterobacter species were collected from different clinical specimens at the microbiology laboratory of BSMMU between August, 2018 and September, 2019. The two main species of Enterobacter, E.cloacae and E.aerogenes were identified by biochemical tests. Antimicrobial susceptibility testing was performed by Kirby Bauer disc diffusion method and reported according to CLSI guidelines. Majority (56%) of the isolated Enterobacter were E.cloacae, 40% were E.aerogenes and 4% were other species. The Enterobacter isolates showed relatively high resistance rates to the cephalosporins including cefoxitin (82%), cefixime (62%), ceftazidime (46%) and ceftriaxone (46%). Resistance to the carbapenems and aminoglycosides was relatively low. The high resistance rates of Enterobacter species to multiple antibiotics makes it necessary for antimicrobial susceptibility testing to be conducted prior to antibiotic prescription. Bangladesh J Med Microbiol 2019; 13 (2): 3-6


2021 ◽  
Vol 15 (06) ◽  
pp. 833-839
Author(s):  
Mohammad Aadam Bin Najeeb ◽  
Ayush Gupta ◽  
Shashank Purwar ◽  
Vishnu Teja Nallapati ◽  
Jogender Yadav ◽  
...  

Introduction: We prospectively evaluated EUCAST rapid antimicrobial susceptibility testing methodology for susceptibility testing directly from blood culture bottles in comparison to CLSI disk-diffusion method. Methodology: During May-November 2019, positively flagged blood culture bottles showing Gram-negative micro-organisms were simultaneously processed by rapid antimicrobial susceptibility testing and CLSI methodology. Antibiotics tested were cefotaxime, ceftazidime, piperacillin-tazobactam, imipenem, meropenem, gentamicin, tobramycin and trimethoprim-sulphamethoxazole. Results: Overall, 80 isolates identified as Escherichia coli (n = 24, 30%), Klebsiella pneumoniae (n = 15, 18.7%), Pseudomonas aeruginosa (n = 16, 20%) and Acinetobacter baumannii (n = 25, 31.2%) were included. Categorical agreements  of rapid antimicrobial susceptibility testing at 4-, 6- and 8-hour reading times were 88.1% (304/345), 90.8% (425/468) and 92.3% (467/506), respectively. Major Error rates were 14% (21/150), 4.9% (10/206) and 4/236 (1.7%), whereas Very Major Error rates were 1.1% (2/177), 1.3% (3/232) and 3.3% (8/243), respectively. Results categorized as “Area of Technical Uncertainty” were significantly lower at 8-hour {10.2% (39/384) vs 5.2% (28/534), 4- vs 8-hour, p = 0.003, Fischer’s exact test}. Conclusions: Except for a slightly higher Very major error rate, rapid antimicrobial susceptibility testing at 8-hour is equivalent to Disk-diffusion method (CLSI-M100) using CLSI-M52 criteria for equivalence: (Categorical agreement ≥ 90%, Very major error ≤ 1.5% and Major error ≤ 3%). Poor Categorical agreements at all reading times were noted for piperacillin-tazobactam, ciprofloxacin and E. coli. Performance of rapid antimicrobial susceptibility testing methodology in resource limited settings brings unique challenge of identifying micro-organisms within 8 hours. We suggest reading and reporting of results at a single time point using rapid antimicrobial susceptibility testing method i.e. at 8-hour.


2021 ◽  
Vol 8 ◽  
Author(s):  
Jingjia Zhang ◽  
Peiyao Jia ◽  
Ying Zhu ◽  
Ge Zhang ◽  
Yingchun Xu ◽  
...  

Purpose: The infection of carbapenem-resistant Enterobacterales (CRE) has become a major clinical and healthcare problem worldwide. The screening methods of CRE have been extensively developed but still need improving [e.g., tests with accurate and simple minimum inhibitory (MICs)]. In this study, the performance of the BD Phoenix NMIC-413 AST panel was evaluated against clinical CRE and carbapenem-susceptible Enterobacterales (CSE) in China. The panel was first evaluated in the Chinese clinical lab.Methods: Antimicrobial susceptibility testing of 303 clinical Enterobacterales isolates were conducted by broth microdilution (BMD), Phoenix NMIC-413 AST panel, and disk diffusion method for imipenem, ertapenem, and meropenem. Considering BMD is a gold standard, essential agreement (EA), categorical agreement (CA), minor error (MIE), major error (ME), and very major error (VME) were determined according to CLSI guidelines. CA and EA > 90%, ME <3%, and VME <1.5% were considered as acceptable criteria. Polymerase chain reaction and sanger sequencing were performed to determine the β-lactamase genotypes of CRE isolates.Results: Three hundred and three isolates included 195 CREs and 108 CSEs were enrolled according to the BMD-MIC values of three carbapenems. Tested CREs showing 100 blaKPC−2-positive organisms, 31 blaIMP-positive organisms, 28 blaNDM-positive organisms, 5 blaVIM-positive organisms, 2 both blaIMP and blaVIM-positive organisms, 2 blaOXA−48-positive organisms, and 27 isolates without carbapenemase genes. For the Phoenix NMIC-413 method, CA and EA rates >93%, MIE rates <5%, ME rates <1.75%, and VME rates were 0%, across the three drugs. For the disk diffusion method, the CA rates for three drugs were all >93%, while the MIE and ME rates were all <5 and <3%, respectively. VME rate was 3.28% for imipenem, exceeded the cut-off value specified by CLSI M52, 0 and 0.56% for ertapenem and meropenem, separately.Conclusion: Based on the genomic data, the detection of CRE and CSE was more reliable using the BD Phoenix NMIC-413 panel compared to the BMD and disk approaches. Therefore, our study supports the use of BD Phoenix NMIC-413 panel as a suitable alternative to BMD for the detection of carbapenem resistant isolates in a clinical setting.


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