In vitroantimicrobial susceptibility testing of rapidly growing mycobacteria using the tablet diffusion method: resistance pattern of NorwegianMycobacterium fortuitumandMycobacterium chelonaeisolates

Apmis ◽  
1993 ◽  
Vol 101 (1-6) ◽  
pp. 27-32 ◽  
Author(s):  
TERJE HOEL ◽  
JOSÉ B. CASALS ◽  
JAN ENG
Author(s):  
Jamsheera Cp ◽  
Ethel Suman

Objective: The present study aimed at finding the resistance pattern of Pseudomonas aeruginosa and other Pseudomonas species isolated from various clinical specimens in the laboratory.Methods: A total of 150 isolates of different species of Pseudomonas obtained from various clinical specimens processed at the Microbiology laboratory of Kasturba Medical College, Manipal Academy of Higher Education, were taken for this study. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion method and interpreted according to the CLSI guidelines. Biofilm assay was performed by modified O’Toole and Kolter method. The results were analyzed using SPSS 17.0 and Student’s unpaired t-test, Kruskal–Wallis, Mann–Whitney, ANOVA, and Chi-square test. p<0.05 was considered statistically significant.Results: Increased resistance was observed by P. aeruginosa to cefotaxime, cotrimoxazole, levofloxacin, ofloxacin, and ticarcillin clavulanate. There was also a good correlation between antibiotic resistance to aztreonam, netilmicin, and ceftazidime and biofilm production. Results of the present study, therefore, demonstrated the occurrence of resistance to various antipseudomonal agents among the biofilm-producing P. aeruginosa isolates.Conclusion: The present study may help in assessing the seriousness of drug resistance caused by biofilm formation in P. aeruginosa and devise strategies through antibiotic policies to minimize such problems.


Author(s):  
Beena Hosdurg Bhaskar ◽  
Shalini Shenoy Mulki ◽  
Sangeeta Joshi ◽  
Ranjeeta Adhikari ◽  
Bhavana Malavalli Venkatesh

Objective: There is an increasing use of colistin consequent to increase in the infections caused by carbapenem-resistant Klebsiella pneumoniae.The present study was conducted to determine the minimum inhibitory concentration (MIC) of colistin and the resistance pattern of colistin in carbapenem-resistant K. pneumoniae (CRKP) strains in our intensive care unit (ICU).Methods: Antibiotic susceptibility testing for other antimicrobial agents was done by Kirby-Bauer disk diffusion method. MIC of colistin was determined by agar dilution method. The results of antibiotic susceptibility testing were interpreted as per Clinical Laboratory Standard Institute guidelines 2016 and MIC of colistin were interpreted as per European Committee on Antimicrobial susceptibility testing. The carbapenem resistance was phenotypically detected by modified hodge test and imipenem/imipenem ethylenediaminetetraacetic acid disk method.Results: Out of 518 K. pneumoniae, 329 were resistant to carbapenems, and 91 isolates showed resistance to colistin. The MIC of colistin ranged between 4 and >512 ug/ml and MIC90 was 16 ug/L and MIC50 was 4 ug/ml. A majority of the colistin-resistant isolates were found in multidisciplinary ICU (85/91).Conclusion: The emergence of colistin-resistant strains is a major problem due to limited treatment options for infections caused by CRKP carbapenemase producing K. pneumoniae. Colistin should not be used alone, combination therapy should be preferred.


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


Author(s):  
Sunita Kabi ◽  
Bichitrananda Swain ◽  
Swati Jain

Introduction: Onychomycosis is a common fungal infection of nail. It may be caused by dermatophytes, non-dermatophytic moulds or yeasts involving nail bed, nail plate or matrix of nail. As the fungi show variable susceptibility to antifungal drugs and treatment requires long duration of antifungal therapy, so it’s prevalence as well as proper laboratory diagnosis and antifungal susceptibility testing is essential for effective therapy. Aim: To find the prevalence of onychomycosis with demography along with various aetiology and the suitable antifungal drugs used for treatment. Materials and Methods: For this prospective study, over a period of two years a total of 300 nail samples were processed in the Department of Microbiology at IMS and SUM Hospital, Bhubaneswar, Odisha, India. The wet mount for microscopic examination was prepared using 20% Potassium Hydroxide (KOH) and examined after overnight incubation. Culture was done in duplicate in Sabouraud’s Dextrose Agar (SDA) tubes; one with actidione and another without it and both were incubated at 25°C in Biological Oxygen Demand (BOD) incubator. Culture tubes growing yeasts were further subjected to speciation by germ tube test, culture on Chromogenic (CHROM) agar and on cornmeal agar. In-vitro antifungal susceptibility testing was performed against Candida species using disc diffusion method on Muller Hinton agar. Chi-square test was used for statistical analysis of the results. Results: Onychomycosis can affect a wide age group though seen commonly at 31-40 years equally in both male and females. Fingernail infection was observed mostly in female cases. It was caused by Candida species (66%), moulds (24%) and dermatophytes (10%) and out of Candida sp. C.albicans was the main culprit. Although all the Candida strains were susceptible to amphotericin B, still some of them showed resistance to the commonly used antifungals like fluconazole and itraconazole. Conclusion:Candida albicans was the most common aetiological agent which contributed for onychomycosis and showed a variable resistance pattern to the commonly used antifungals. Proper laboratory diagnosis and selection of antifungal drug is essential prior to institution of therapy for successful treatment of this disease.


Author(s):  
Kinjal P. Patel ◽  
Summaiya Mulla

Background: Enterococcus species are well known for its intrinsic resistance pattern to several antibiotics. Hence, appropriate management and prevention is essential in any healthcare facility. Present study was conducted to establish an accessible biochemical tests to differentiate Enterococcus species at resource limited settings.Methods: Enterococci isolated from various clinical specimens were speciated using an array of biochemical reactions and antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion method. Results were interpreted as per Clinical and Laboratory Standards Institute (CLSI) guidelines.Results: Out of 107 enterococcal isolates, 63(59%) were E. faecium, 40(37%) were E. fecalis, 2(2%) were E. hirae, 1(0.9%) was E. raffinosus and 1(0.9%) was E. gallinarum. E. faecium and E. fecalis showed 23% and 7% vancomycin resistance respectively, while E. gallinarum showed low level vancomycin resistance.Conclusions: Enterococcus speciation can be done using simple biochemical reactions and its susceptibility pattern enables to distinguish Van phenotypes too. Hence, it is helpful for management of infections in resource limited settings to a greater extent.


Author(s):  
Archana Bhimrao Wankhade ◽  
Sanjibkumar Panda ◽  
Riddhi Hathiwala ◽  
Yogendra Keche

Background: Staphylococcus aureus is a pathogen causing wide spectrum of infections. It has tendency for the development of multidrug resistance thereby exposing the selection of appropriate treatment. Therefore, the present study was undertaken to find out the antibiotic susceptibility pattern of Staphylococcus aureus isolated from various clinical samples in teaching tertiary hospital.Methods: Total 85 Staphylococcus aureus was isolated from clinical samples (pus, urine, sputum and blood) tested. Identification of Staphylococcus aureus was done by standard conventional microbiological methods. Antibiotic susceptibility testing was done by using disk diffusion method as per CLSI guidelines.Results: Staphylococcus aureus was isolated maximum from pus samples followed by urine samples. Antibiotic susceptibility testing showed highest resistance against Penicillin (69%) and Erythromycin (51%) followed by Cotrimoxazole (50%) & Nitrofurantoin (50%). All the strains were sensitive to Vancomycin. Amongst the urine isolates all were sensitive to Norfloxacin. These percentages of sensitivities are characteristically higher in our study than the previous studies in the literature. In addition, out of 85 Staphylococcus aureus isolates, 26 isolates showed sensitivity   to all antibiotics.Conclusions: From the present study we conclude that though the Staphylococcus aureus is usually having multidrug resistance pattern. So regular antimicrobial susceptibility surveillance is essential for area‐wise monitoring of the resistance patterns. This will be beneficial to preserve the effectiveness of antibiotics and for better patient management.


2020 ◽  
Vol 70 (12) ◽  
pp. 4287-4294

Cancer is the second leading cause of death in Romania and worldwide. Cancer patients are at increasing risk of acquiring bacterial infection with multi-resistant germs, including multidrug-resistant (MDR) strains of Gram-negative bacteria involved in nosocomial infection. Romania is one of the South-Eastern European countries with one of the highest prevalence rates of MDR pathogens. To determine the resistance pattern of bacterial profile and antibiotic resistance pattern in cancer patients admitted at the County Emergency Clinical Hospital Craiova, Romania. A retrospective study of bacterial pathogens was carried out on 90 adult cancer patients admitted from January to December 2018. The analysis of the resistance patterns for the action of the appropriate antibiotics was performed using Vitek 2 Compact system and diffusion method. In this study there were analysed 92 samples from 90 oncological patients (37-86 years). A total of 157 bacterial isolates were obtained, of which 37 strains of Staphylococcus aureus (23.56%), followed by Streptococcus pneumoniae (23- 14.64%), Klebsiella spp. and Escherichia coli (22 - 14,01%). The most common isolates were from respiratory tract (86 isolates - 54.77%). High rates of MDR were found for E. coli (63.63%), MRSA (61,11%) and Klebsiella spp. (54,54%), while one third of the isolated strains of Pseudomonas aeruginosa, Acinetobacter spp. and Proteus spp. were MDR. The findings of this study may be the basis for further more extensive studies highlighting the germs involved in the infectious pathology of cancer patients, in order to determine the antimicrobial resistance and to improve the methods of prophylaxis and treatment. Keywords: multidrug resistance (MDR), cancer patients, bacterial pathogen


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helal F. Hetta ◽  
Israa M. S. Al-Kadmy ◽  
Saba Saadoon Khazaal ◽  
Suhad Abbas ◽  
Ahmed Suhail ◽  
...  

AbstractWe aimed to isolate Acinetobacter baumannii (A. baumannii) from wound infections, determine their resistance and virulence profile, and assess the impact of Silver nanoparticles (AgNPs) on the bacterial growth, virulence and biofilm-related gene expression. AgNPs were synthesized and characterized using TEM, XRD and FTIR spectroscopy. A. baumannii (n = 200) were isolated and identified. Resistance pattern was determined and virulence genes (afa/draBC, cnf1, cnf2, csgA, cvaC, fimH, fyuA, ibeA, iutA, kpsMT II, PAI, papC, PapG II, III, sfa/focDE and traT) were screened using PCR. Biofilm formation was evaluated using Microtiter plate method. Then, the antimicrobial activity of AgNPs was evaluated by the well-diffusion method, growth kinetics and MIC determination. Inhibition of biofilm formation and the ability to disperse biofilms in exposure to AgNPs were evaluated. The effect of AgNPs on the expression of virulence and biofilm-related genes (bap, OmpA, abaI, csuA/B, A1S_2091, A1S_1510, A1S_0690, A1S_0114) were estimated using QRT-PCR. In vitro infection model for analyzing the antibacterial activity of AgNPs was done using a co-culture infection model of A. baumannii with human fibroblast skin cell line HFF-1 or Vero cell lines. A. baumannii had high level of resistance to antibiotics. Most of the isolates harbored the fimH, afa/draBC, cnf1, csgA and cnf2, and the majority of A. baumannii produced strong biofilms. AgNPs inhibited the growth of A. baumannii efficiently with MIC ranging from 4 to 25 µg/ml. A. baumannii showed a reduced growth rate in the presence of AgNPs. The inhibitory activity and the anti-biofilm activity of AgNPs were more pronounced against the weak biofilm producers. Moreover, AgNPs decreased the expression of kpsMII , afa/draBC,bap, OmpA, and csuA/B genes. The in vitro infection model revealed a significant antibacterial activity of AgNPs against extracellular and intracellular A. baumannii. AgNPs highly interrupted bacterial multiplication and biofilm formation. AgNPs downregulated the transcription level of important virulence and biofilm-related genes. Our findings provide an additional step towards understanding the mechanisms by which sliver nanoparticles interfere with the microbial spread and persistence.


Author(s):  
Rustini Rustini ◽  
Jamsari Jamsari ◽  
Marlina Marlina ◽  
Nasrul Zubir ◽  
Yori Yuliandra

Objectives: Pseudomonas aeruginosa is an opportunistic pathogen that has an innate resistance to some antibiotics. This bacterium is one of the mostcommon causes of nosocomial infections that include surgical wound infections, burns, and urinary tract infections. The bacteria have been reportedlyresistant to many antibiotics and have developed multidrug resistance (MDR). The objective of the study was to determine the resistance pattern ofP. aeruginosa isolated from clinical samples of patients against some major antibiotics.Methods: Isolates of P. aeruginosa were obtained from clinical sample of urine, sputum, swabs, pus, feces, and blood and cultured in cetrimide agar. P.aeruginosa ATCC 27853 was used as a positive control. The antibacterial susceptibility testing was conducted against 13 antibiotics: Ceftazidime, cefotaxime,ceftriaxone, cefoperazone, ciprofloxacin, levofloxacin, ofloxacin, gentamicin, amikacin, piperacillin, ticarcillin, meropenem, and imipenem. The examinationwas carried out using agar diffusion method of Kirby-Bauer and following the standards from Clinical and Laboratory Standards Institute (CLSI).Results: The results showed that bacterial resistance was established against all tested antibiotics. The highest number of resistance was shownagainst ceftriaxone (44.21%), whereas the most susceptibility was exhibited against amikacin (only 9.47% of resistance). MDR P. aeruginosa (MDRPA)was detected on almost all clinical samples tested, except the feces. The sample with the highest percentage of MDRPA was the pus.Conclusion: The study concludes that the most effective antibiotic against P. aeruginosa is amikacin (91.51%), whereas the most resistance is exhibited to ceftriaxone (43.16%).


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