Showing 25 results for Microbial
Abolfazl Shirdel Abdolmaleki, Abolfazl Rafati Zomorodi, Mohammad Motamedifar, Yalda Malekzadegan,
Volume 18, Issue 1 (1-2024)
Abstract
Background: Urinary tract infection (UTI) is one of the most common bacterial infections of all ages and sexes. Escherichia coli is reported as the most common predominant pathogen. Urinary tract infection treatment leads to abundant antibiotic application in hospitals and communities, continuously developing multidrug resistance (MDR). This study aimed to determine the sensitivity and resistance pattern to common antibiotics among E. coli isolates from patients with UTIs at Nemazee Hospital in Shiraz.
Methods: This retrospective cross-sectional survey studied 1910 positive urine samples with E. coli bacteria from patients referred to Nemazee Hospital from 2018 to 2019. Antimicrobial susceptibility testing was performed on 12 commonly used antibiotics for UTIs.
Results: A total of 1910 E. coli isolates were gathered during these 2 years. The most highlighted resistance was observed against quinolones and cephalosporins at 86.9% and 89.7%, respectively. Cephalexin (87.9%) and nalidixic acid (86.1%) have shown the lowest activity against E. coli isolates. Also, the highest susceptibility was determined for amikacin (88.3%), nitrofurantoin (76.8%), and gentamicin (70.6%). In addition, 1624 (85%) isolates were MDR.
Conclusion: In conclusion, resistance to antibiotics (such as ciprofloxacin, norfloxacin, tetracycline, cefotaxime, and nitrofurantoin) is increasing. Therefore, it is vital to follow an appropriate antimicrobial stewardship program.
Hina Rahangdale, Tejaswini Olambe, Priyanka Klabhor, Sangita Bhalavi, Varsha Wanjare, Sunanda Shrikhande,
Volume 18, Issue 2 (3-2024)
Abstract
Background: Urinary tract infections (UTIs) are among the most common types of infections affecting people in community and hospital settings. Bacteria are the leading cause of UTIs, followed by fungi. 39% of all healthcare-associated infections (HAIs) affecting all age groups are UTIs, causing high morbidity and mortality rates. The antibiotic susceptibility pattern of causative organisms is changing due to improper antibiotic use. The study was conducted to determine the microbiological profile of both community and HAIs and their antimicrobial susceptibility pattern.
Methods: Clean-catch, mid-stream urine samples collected in the universal wide-mouthed sterile containers were transported to the laboratory. Samples were processed by standard conventional microbiological procedures. Antimicrobial susceptibility was done using the Kirby-Bauer disc diffusion method on Mueller-Hinton agar plates.
Results: The most common causative organisms among gram-negative bacteria were E coli (26.05%), followed by Klebsiella spp (20.37%), and Enterococcus spp (12.81%) was more common among the gram-positive bacteria. Non-albicans Candida (64.10%) were more commonly isolated than Candida albicans (35.90%). E coli was highly susceptible to nitrofurantoin and fosfomycin, and Klebsiella spp and Enterococcus spp were similarly highly susceptible. Antibiotic resistance was more common among bacteria isolated in HAIs.
Conclusion: In both settings, E coli was the most common causative organism. The incidence of non-albicans Candida species has increased in comparison to Candida albicans. Antimicrobial susceptibility to empirical 3rd-generation cephalosporins and fluoroquinolones has drastically decreased. Hospital-acquired UTIs are a rising threat to the healthcare system and community. Based on hospitals’ antimicrobial policy formulated by studying antimicrobial susceptibility patterns, empirical treatment should be chosen.
Kirandeep Kaur,
Volume 18, Issue 3 (5-2024)
Abstract
Escherichia coli is a Gram-negative, rod-shaped bacterium, responsible for 90% of all community-acquired infections and 50% of hospital-acquired infections, with opportunistic infections found in intensive care unit (ICU) patients. The β-lactam antibiotics, which inhibit cell wall synthesis, are known for their high efficacy and broad-spectrum activity. They also have low toxicity and provide long-term effects, making them widely used drugs against Gram-negative bacteria. Bacteria develop resistance to β-lactams primarily through the expression of hydrolytic enzymes, called β-lactamases, which are divided into serine β-lactamases (Classes A, C, and D) and metallo-β-lactamases (Class B), based on their molecular mechanism. This study aimed to clarify the mechanism of action of β-lactams against Gram-negative bacilli and to emphasize the multidrug resistance of cephalosporins and carbapenems to E. coli.
Sujata Lall , Vivek Bhat, Sanjay Biswas, Navin Khattry ,
Volume 18, Issue 4 (7-2024)
Abstract
Background: Tigecycline susceptibility testing and reporting remain enigmatic due to the lack of established guidelines. Disc diffusion, as a method of performing susceptibility testing, is more widely accepted worldwide due to its ease of use. Limited published literature is available from India on the utility of this method, especially in a cancer care setting. Hence, this study was conducted to evaluate the performance characteristics of disc diffusion by comparing its results with those of the VITEK-2 COMPACT, considering the latter as the standard.
Methods: Disc diffusion was performed using Kirby-Bauer’s method on Mueller-Hinton agar with a HiMedia 15 mcg TGC disc, following FDA and EUCAST breakpoints. According to CLSI criteria, disc diffusion breakpoints can be considered acceptable when categorical agreement is ≥ 90%, the very major error is ≤ 1.5%, and the major error is ≤ 3%.
Results: Using Cohen’s kappa coefficient, the kappa value was 0.328, with a p-value of <0.05. The agreement percentage observed was 60.84%. Two strains reported as resistant by VITEK-2 COMPACT were misclassified as sensitive by disc diffusion, resulting in a very major error rate of 0.76%. A major error rate of 9.5% and a minor error rate of 27.7% were noted, as 25 strains reported as susceptible were identified as resistant.
Conclusion: Since poor agreement was observed, exceeding the acceptable performance rate, the disc diffusion method was unacceptable according to CLSI criteria. There is a gap in uniformity and a lack of streamlined, harmonized TST, which might become an alarming cause for concern.
Zahra Askari, Zeynab Mirzapour, Tooba Shafighi, Reyhaneh Ghorbanpour,
Volume 19, Issue 1 (1-2025)
Abstract
Background: Urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) represent a significant global health concern. Virulence factors (VFs) expressed by UPEC strains play a crucial role in promoting bacterial pathogenicity within the urinary tract. Effective treatment of these infections is frequently complicated by the high prevalence of antimicrobial resistance exhibited by Escherichia coli. The objective of this study was to investigate the VFs and antibiotic susceptibility profiles of UPEC strains isolated in the northern region of Iran.
Methods: One hundred and five urine specimens were collected from female patients diagnosed with UTIs in Rasht, located in the north of Iran. These samples underwent culturing on both Eosin Methylene Blue (EMB) agar and MacConkey agar. Following a 24-hour incubation period at 37°C, pure bacterial isolates were identified through Gram staining and a battery of standard biochemical assays. The prevalence of six VF genes - papC, sfa/foc, fimH, afa, ibeA, and neuC - within UPEC strains was determined utilizing polymerase chain reaction (PCR) and subsequently confirmed via direct sequencing. Antibiotic susceptibility testing (AST) was conducted using the disk diffusion method, adhering to the guidelines established by the Clinical and Laboratory Standards Institute (CLSI M02).
Results: The study identified 65.71% of the isolates as Escherichia coli. Among the virulence genes examined, fimH exhibited the highest prevalence (100%), while afa was the least frequent (1.44%). Antibiotic resistance analysis revealed the highest rate against Cefazolin (66.66%) and the lowest against Gentamicin (24.63%). Notably, the prevalence of multi-drug resistance (MDR) was determined to be 73.91%.
Conclusion: This study underscored the significance of localized surveillance of UPEC isolates. This emphasis stems from the pathogen's considerable capacity for genetic mutation, coupled with the influence of environmental variables and individual patient characteristics. Understanding these dynamic factors at a local level is crucial for formulating the most effective strategies to combat UTIs.
