جستجوی مقالات مرتبط با کلیدواژه « Antimicrobial drug resistance » در نشریات گروه « پزشکی »

Over the last decade, hospital-acquired infections, particularly in the critical care setting, have become more common, with Gram-negative bacterial infections having the highest prevalence. This study aims to determine the prevalence and antibiotic susceptibility pattern of Pseudomonas species to WHO’s, aware class of antibiotics, which are commonly prescribed across various ICU’s, medical and surgical wards of our tertiary care teaching hospital.

This prospective study conducted from January 2021 to June 2022 at a tertiary care centre of central India identified Pseudomonas species from clinical samples using standard procedures and antimicrobial susceptibility testing performed as per Clinical Laboratory Standards Institute (CLSI) guidelines (M100; 32th Edition).

A total of 1490 non duplicate Pseudomonas species isolates were grown from 21,019 culture positive clinical samples, of which 1247 were Pseudomonas aeruginosa. Out of these 1247 Pseudomonas aeruginosa 384 were MDR (30.7%). Pseudomonas aeruginosa were most commonly isolated from the pus samples (85%). ICU isolates were significantly more resistant to antibiotics than those from other units. P. aeruginosa strains from ICUs showed the highest rates of resistance to ceftazidime (93.9%). Reserve drug colistin showed good susceptibility (98.2%). All the 18 colistin resistant strains were found to be negative for plasmid mediated mcr-1,2,3 genes.

The study shall help to generate and disseminate the data so that proper antibiotic policy can be made for judicious use of Access, Watch and Reserve antibiotics and antibiotic de-escalation plan can be put forth.

Antimicrobial resistance has emerged as a significant global health threat. Infections caused by Multi Drug-Resistant (MDR) bacteria pose formidable challenges in terms of treatment options and patient outcomes. Pus cultures serve as crucial diagnostic tools in identifying the agents responsible for various infections, and their antimicrobial susceptibility patterns which help in establishment of empirical therapy guidelines. This study was conducted to determine the pathogen and its susceptibility pattern from pus cultures and to generate antibiogram in our tertiary care setting.

It was a cross-sectional study, conducted for a period of six months, from July 2022 to December 2022, in the Pathology Department of Pakistan Institute of Medical Sciences (PIMS).

Out of total 2507 samples received, 1242 (49.5%) showed positive culture. Among the 1242 positive samples, 364 were Gram positive cocci (GPCs) and 878 were Gram negative rods (GNRs). Methicillin resistant Staphylococcus aureus (MRSA) was the most common isolate (23%) followed by Klebsiella pneumoniae (22.6%), Pseudomonas aeruginosa (16.9%), Enterobacter spp. (15.5%) and Escherichia coli (14.2%). Vancomycin was found to be highly effective (100%) against MRSA. GPCs were highly susceptible to linezolid (98%) while GNRs showed high level of sensitivity to colistin (96%) and tigecycline (92%).

The generation of a local antibiogram specific to the hospital setting is essential to effectively manage infections empirically and preserve the efficacy of existing antibiotics. By implementing antimicrobial stewardship practices based on a better understanding of antibiotic susceptibility patterns, we can contribute to the mitigation of antibiotic resistance and improve patient outcomes.

Antibiotic resistance is a significant problem that restricts the options for treating bacterial pneumonia. This research aimed to determine the bacterial causes of pneumonia and antibiotic resistance among hospitalized patients in southwest Ethiopia.

We collected and analyzed 150 sputum samples from individuals with community-acquired pneumonia from April 1st to October 30th, 2019. Standard bacteriological procedures were used to identify the bacteria. Kirby Bauer's disk diffusion method was used to assess the bacteria's susceptibility patterns. Production of carbapenemase and extended-spectrum-lactamase were confirmed phenotypically. Odds ratios and the chi-square test were computed.

On the whole, bacterial pathogens were verified in 50% of the sputum samples. The predominant bacterial isolates were Klebsiella species, followed by Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pneumoniae. About 77.5% of isolates were multidrug resistant. Moreover, 40.5% and 10.8% of the isolates were ESBL and carbapenemase producers, respectively. Aging, tobacco smoking, previous history of pneumonia, heart disease, and chronic respiratory disease had association with sputum culture-positivity.

As a result, it is important to regularly monitor the bacterial etiologies and their patterns of resistance. Additionally, sociodemographic and clinical characteristics should all be taken into account while managing patients with pneumonia empirically in this context.

Carbapenems are considered the last resort to treat several infections, particularly in intensive care units (ICUs). However, increasing carbapenem resistance is problematic because it leads to high morbidity and mortality rates. This study aimed to determine the rate of carbapenem resistance among Gram-negative bacteria collected from patients in ICUs and to identify their resistance mechanisms using phenotypic and genotypic methods.

Antimicrobial susceptibility testing was carried out using the disc diffusion method among 180 Gram-negative bacterial isolates. Productions of carbapenemases, metallo-beta-lactamases (MBLs) and the harboring of carbapenemase-encoding genes, were detected in 40 selected carbapenem-resistant Gram-negative bacteria (CR-GNB).

Of 40 selected CR-GNB isolates, 28 (70%), and 20 (50%) isolates were phenotypically positive for carbapenemase, and MBL production, respectively. Furthermore, 22 (55%) showed amplification of one or more of the carbapenemase-encoding genes, including blaNDM-1, blaVIM-2, and blaOXA-48. This study described the first emergence of NDM-1 producing Klebsiella oxytoca in Egyptian ICUs.

High incidence of CR-GNB detected in the ICUs in our study area may be attributed to the overuse of antibiotics, including carbapenems, and improper application of infection control measures. These findings confirm the need for the application of a strict antibiotic stewardship program.

Antimicrobial resistance in ESKAPEEc (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter species, and Escherichia coli) pathogens causing bloodstream infections is a growing threat to clinicians and public health.

Our purpose was to determine the prevalence and susceptibility of ESKAPEEcs causing bloodstream infection over five years (2016 to 2020) at a large tertiary hospital in Istanbul, Turkey.

Of 2591 unique isolates obtained from blood culture specimens, 1.281 (49.4%) were positive for ESKAPEEc pathogens. The ESKAPEEc rates increased from 2016 to 2019 and decreased during the COVID-19 pandemic.

The most common pathogen was K. pneumoniae (34.3%). Carbapenem resistant K. pneumoniae was 61.8% and A. baumannii was 90.4%. The percentages of methicillin-resistant S. aureus and vancomycin-resistant E. faecium were 38.6% and 29.4%, respectively.

Our findings showed a high incidence of ESKAPEEc and antimicrobial resistance in bloodstream infections. Antibiotic policies and restrictions in health care settings and the community will play an essential role in the solution in the future.

 Despite the critical importance of catheter as an indwelling medical device, its prolonged utilization in hospitalized patients may lead to infection. This study aimed to identify distribution of uropathogenic bacteria isolated from catheterized uro-oncology patients, their biofilm production, and antimicrobial resistance patterns to generally -used antibiotics.

 The urine samples of catheterized urology cancer patients were collected for urinalysis and urine culture. Then capability of biofilm production was detected by Congo red agar method, tube method, and microtiter plate assay. Antimicrobial susceptibility test was also performed using the Kirby–Bauer disc diffusion method on Muller–Hinton agar. Subsequently, polymerase chain reaction (PCR) assays were used to detect the biofilm encoding genes.

 Of the 100 urinary catheter samples, 76 isolates were recovered from urinary catheters of 52 patients. Escherichia coli was established to be the most frequent pathogen isolated from the urine of patients followed by Pseudomonas and Staphylococcus. All of Pseudomonas aeruginosa and Methicillin-resistant Staphylococcus aureus (MRSA) isolates were found to be biofilm producers. All studied isolates were found resistant to ampicillin, amoxicillin, and cephalexin. All biofilm- producer MRSA and Pseudomonas isolates were found to harbor the virulence genes studied. Both imipenem and fosfomycin were the most effective antibiotics against isolated bacteria.

 In our study virulent pathogens with highly- resistant profile and potential to form biofilm were isolated from uro-oncology patients. Therefore, the current study highlights the significance of antibiotic resistance which can lead to treatment failure.

 Today, one of the problems of health systems is the presence of cockroaches in hospitals as insects that move freely in and out of the hospitals and are infected with pathogenic bacteria. The aim of this study was to identify carbapenem resistance genes in Escherichia coli isolated from Blattella germanica by dot blot assay in Hamadan hospitals in the west of Iran.

 A total of 109 B. germanica from April to September 2018 were collected from ICUs of different hospitals in the Hamadan province, located in western Iran. The B. germanica were identified using reliable taxonomic keys by an expert in the Department of Entomology, insectarium Hamadan University of Medical Sciences, Iran. The antimicrobial susceptibility test was determined by disk diffusion. The dot blot assay was used to identify resistance genes in E. coli isolated from B. germanica.

Out of 109 B. germanica samples collected from ICUs of different hospitals in Hamadan, 31 samples (28.44%) were positive for E. coli. The highest frequency of antibiotic resistance against ampicillin (100%) and the lowest resistance to imipenem was observed in two isolates (6.45%). The frequency of genes among E. coli isolates in B. germanica was as follows: bla NDM (4 isolates: 3.66%), bla OXA-48 (one isolate: 0.92%), and other studied genes were not observed in any of the strains.

 Cockroaches are an important factor in transmitting Enterobacterales and multidrug-resistant (MDR) strains. Therefore, effective preventive and control measures are needed to reduce vector-borne diseases.

Globally, Acinetobacter spp., most commonly, Acinetobacter baumannii, are one of the most common Gram-negative nosocomial infections, especially in Intensive Care Units (ICUs) and burn wards. Because of the pathogens’ ability to survive for a long time, the eradication of the pathogen from these wards remains a great concern. Simultaneously, the remarkable increase in antibacterial resistance among A. baumannii strains in recent years has raised a great deal of concern.

The study assessed the prevalence and antibacterial resistance pattern of A. baumannii in the only academic-affiliated burn center in northeastern Iran in 2012-2014.

In this cross-sectional study, 5,080 samples from patients admitted to two burnt wards and one burn ICU were included. The samples were from different sources including wound tissue, blood, bronchial secretion, and urine. The antibacterial resistance pattern was determined using relevant antibiotics based on the Clinical and Laboratory Standards Institut (CLSI) instructions.

Acinetobacter spp. were found in 39% of the acquired cultures (1,985 out of 5,080) and 51.9% of bacterial positive cultures (1985 out of 3823). The resistance rate of Acinetobacter spp. against antibiotics varied from 0.9% for colistin to 100% for piperacillin-tazobactam. All Acinetobacter spp. were multidrug-resistant (MDR) due to considerable resistance to fluoroquinolones (95%), cephalosporins (93% - 98%), penicillins (97%), carbapenems (94% - 95%), and beta-lactamase inhibitors (87% - 100%).

Given that infections are a major cause of mortality in burn wards, the high prevalence of MDR isolates of Acinetobacter spp. in this burn center suggests that local antibiotic prescription policies should be revised and infection control strategies should be improved. Also, antibiotic cycling and restrict infection control strategies should be implemented in high-risk wards such as burn units.

About 73% of death cases in the first 5 days after burning are due to infection complications. The aim of this study was to identify the causing agents of infections in burn patients and the sensitivity pattern of them to the commonly used antimicrobials in an Iranian Burn center University Hospital.

In this cross-sectional study, patients who were admitted to one of the Iranian Burn center University hospitals in 2009 and had nosocomial infection due to burn wound, whom received antimicrobial agents for therapeutic reasons, with a hospitalization period of more than 48 hours were enrolled. Gram stain analyses were performed to help identifying growing colonies. Differential tests for identification of pathogenic bacteria species were performed following primary tests. E-test strips of each antimicrobial were placed on the culture medium plate in order to determine the minimum inhibitory concentration Studied antimicrobials for isolated Gram-negative bacteria were meropenem, piperacillin/tazobactam, ceftriaxone, cotrimoxazole, and for Staphylococcus aureus, vancomycin, piperacillin/ tazobactam, cotrimoxazole, and cephalothin.

Only 16% of Pseudomonas aeruginosa species were sensitive to meropenem, and 13% were sensitive to piperacillin/tazobactam. Ten out of 29 Klebsiella species (34%) were sensitive to meropenem and piperacillin/tazobactam. All isolated strains of Staphylococcus aureus were sensitive to vancomycine while they were all resistant to cotrimoxazole.

Pseudomona, Klebsiella and Staphylococcoci are the most common species causing burn infection in this medical center. Results showed the importance of limiting irrational use of wide-spectrum antimicrobials and recommends strict management of infections in burn injury centers.

Resistance to ciprofloxacin as the most common antibiotic for the treatment of urinary tract infections (UTIs) is increasing. In this study, the role of gyrA and qnrA genes among ciprofloxacin resistant Escherichia coli (E. coli) isolates from UTIs was evaluated.

During September to March 2014, urine samples were collected from patients with UTIs of Imam Khomaini hospital of Tehran. Bacterial identification was done based on standard tests. The antibiotic sensitivity test was performed based on the clinical and laboratory standards institute (CLSI) 2014 protocol and minimal inhibitory concentration (MIC) of ciprofloxacin was determined by E-test strips. DNA was extracted by the boiling method and assessment of gyrA (DNA gyrase (type II topoisomerase)) and qnrA genes was done by the polymerase chain reaction (PCR). Further sequencing was done for PCR confirmation and blasting.

All isolates were susceptible to carbapenems (100%) and 98.7% were susceptible to nitrofrontain. The highest resistance was towards piperacillin 85%, ampicillin 83.8%, sulfamethoxazole trimethoprim (SXT) 78.7%, ciprofloxacin 77.5%, and 75% tetracycline. Around 80% of the E. coli isolates were identified as multi drug resistant (MDR). All isolates with MIC of ≥ 4 μg/mL for ciprofloxacin were the candidates for DNA extraction, PCR, and sequencing. The gyrA and qnrA genes were detected in 100% and 39% of isolates, respectively. Mutations were found in the sequence analysis, yet the mean full change was related to change of serine to leucine at position 83 (S 83 L).

Finally, contribution of both mutated chromosomal gyrA genes and plasmidic qnrA resistance genes in some of the high ciprofloxacin resistant bacterial strains was found in this study, besides the overuse of antibiotics, which can increase the emergence of resistant strains

Urinary tract infection is the second most common cause of infection in the human body. Among bacteria of the urinary tract, Escherichia coli is the most common bacteria causing urinary tract infection.
The purpose of this study was to investigate the antimicrobial susceptibility of antibiotics used in the treatment of urinary tract infections through the microdilution method and comparing it with disk diffusion.
E. coli strains were collected from urinary tract infections from patients of Zabol hospital. Antimicrobial resistance pattern was investigated by diffusion and microdilution methods on E. coli strains. DNA extraction was performed using the phenol chloroform method and finally, the polymerase chain reaction (PCR) was carried out for the OXa gene.
The results of this study showed that E. coli was resistant to antibiotics, including amikacin (AN; 42.85%), cefazolin (CZ; 35.71), amoxicillin-clavulanic acid (AMC; 35.71%), ampicillin (AM; 35.71%). The results of PCR to detect the OXa gene showed that five strains (35.71%) were carriers of the OXa gene.
Antibiotic resistance pattern was different in different regions and also, relative resistance to newer antibiotics is increasing. For this reason, antibiotic resistance patterns are used in experimental and specific treatment of urinary tract infections.

Septicemia is a life-threatening condition particularly among pediatric population. Early initiating a proper empiric antimicrobial treatment prior to definite isolation of the pathogen through blood culture has pivotal role in reducing further mortality and morbidity. The aim of this study was to evaluate the epidemiological properties of a distinct Iranian population by patients’ age and gender throughout the year.
As a retrospective study between March 2013 and March 2017, all consecutive patients referred to the Hazrat Masumeh hospital of Qom-Iran with suspicious of septicemia were reviewed. Patients with prior history of antibiotic consumption as well as patients over 6 years of age were excluded; incomplete hospital records were also excluded from further evaluations. Prespecified data-extraction forms were used to collect data including characteristics of patients and the results of antibiogram.
Total of 378 patients were enrolled in this study and 200 of them were boys (52.91%). Escherichia coli (11.6%) and Klebsiella (9.5%) were the most common isolated pathogens (Gram-negative) after coagulase-negatives. Escherichia coli, Citrobacter (Gram-negative), and Staph. Aureus (Gram-positive) were the most common pathogens among age group of 0-1 year. Winter had the greatest outbreak of bacteremia (29.1%) and the autumn had the least incidence (21.4%). The least and the most antimicrobial resistance were associated with Imipenem (1.8%) and Ampicillin (78.78%), respectively.
Escherichia coliand Klebsiella were the most common isolated bacteria in patients suspected to bacteremia in our region. Imipenem and Ampicillin had the least and the most antimicrobial resistance in our population, respectively.

In recent years, three new aminoglycoside resistance genes such as aph (3ʹ)-IIIa and ant (4ʹ)-Ia, that encode for the APH (3ʹ) and ANT (4ʹ) have also been identified. The aim of this study was to come up with a multiplex-PCR procedure for detection of aac(6ʹ)-Ie–aph(2ʹʹ)-Ia, aph(3ʹ)-IIIa, ant(4ʹ)-Ia genes in the Enterococcus spp. clinical isolates.

100 samples were isolated from various specimens, from various hospitals in Tehran, Iran. The grown colonies were identified by standard biochemical and disc diffusion tests. Multiplex-PCR for aac (6’)-Ie -aph(2’’)-Ia , aph(3ʹ)-IIIa, ant(4ʹ)-Ia genes amplification were performed in order to confirm bacterial colonies as Enterococcus spp.

Eighty four (84%) Enterococcus spp. isolates were collected from the 100 specimens. The highest and lowest isolates were related to urine (48%) and sputum (2%). Antibiotic susceptibility test results showed that the highest and lowest resistance was related to tetracycline and nitrofurantoin, respectively. Multiplex PCR results revealed that aac (6ʹ)-Ie-aph (2ʹʹ)-Ia, ant (4ʹ)-Ia and aph (3ʹ)-IIIa genes were present in 6% of the isolated bacteria from the urine, 2% from the wound and 1% from the pleural samples. the aac (6ʹ)-Ie-aph (2ʹʹ)-Ia and aph (3ʹ)-IIIa genes were present in 25% of the isolated strains from the urine, 3% from the wound and 2% from the plural specimens. Nine percent of the strains were isolated from the urine, 3% from the wound and 1% from the plural were positive for aac (6ʹ)-Ie-aph (2ʹʹ)-Ia and ant (4ʹ)-Ia genes.

we had observed enterococci isolates with phenotypic resistance to HLAR and demonstrated aac(6′)-Ie-aph(2′′)-Ia and aph(3′)-IIIa genes more frequently occurring than other genes. A collection of AMEs are accountable for HLAR status among Enterococcus species. The aac (6ʹ)-Ie-aph (2ʹʹ)-Ia gene was detected more frequently than the other genes.

Spina bifida increases the risk for urinary tract infections (UTI). Antimicrobial prophylaxis (AP) reduces symptomatic UTI’s but selects resistant organisms. Measures to ensure regular and complete emptying of the bladder combined with treatment of constipation reduce the risk for UTI..
Demonstrate that close adherence to a catheterization regimen in children with spina bifida (Selective Treatment - ST) reduces the need for antimicrobial prophylaxis..
Case series analysis of pediatric spina bifida clinic patients where routine antimicrobial prophylaxis was replaced by clean-catch catheterization and daily bowel regimen (ST). Retrospective chart review of 67 children (mean entry age: 24 months, median age: 4 months; 32 Males, 35 Females) enrolled between 1986 - 2004. Mean follow-up was 128.6 months (range 3 - 257 months). Asymptomatic and symptomatic UTI incidences were noted on AP and ST protocols. Creatinine clearance at study entry and follow-up was calculated by the age appropriate method. A multivariable regression model with delta Glomerular Filtration Rate (GFR) as the dependent variable, independent sample t-test and Wilcoxon rank sum were performed with SAS v. 9.2..
The mean number of infections while on AP was 8.7 (95% CI 5.72, 11.68) and was 1.0 on ST (95% CI 0.48, 1.43). 5 infections on the AP protocol required intravenous (IV) antibiotics due to resistance to oral therapy, but none on ST. Comparing change in GFR between both protocols (AP vs. ST) found a significant difference in the change of GFR by treatment protocol..
AP did not prevent UTIs and resulted in more resistant organisms requiring IV antibiotics. Discontinuing AP allowed the return of susceptibility to oral antimicrobials and significantly improved GFR in those children who had previously been on AP. Adherence to a catheterization regimen with prompt treatment of symptomatic UTI conserved renal function and prevented selection of resistant organisms..

Pseudomonas aeruginosa is considered as a major cause of hospital-acquired infections due to its high antibacterial resistance. Biofilm formation is a well-known pathogenic mechanism in P. aeruginosa infections, since sessile bacteria are protected in an extracellular matrix of exopolysaccharide. The expression of polysaccharide synthesis locus (pslA gene) can be important for biofilm formation by P. aeruginosa. The purpose of this research was to evaluate the antibiotic resistance pattern and distribution of the pslA gene among biofilm-producing P. aeruginosa isolates obtained from waste water of Burn Centre in Guilan, Iran. Fifty isolates of P. aeruginosa were obtained from waste water of a burn center. The P. aeruginosa isolates were identified using standard bacteriological procedures. Drug susceptibility test was performed by disk diffusion method for all the isolates against nine antimicrobial agents. Biofilm formation was measured by microtiter plate assay. Polymerase chain reaction (PCR) was used to identify the presence of the pslA gene among the isolates. Biofilm formation was observed in 70% of the P. aeruginosa isolates. The potential formation of biofilm was significantly associated with resistance to gentamicin, imipenem, tobramycin and piperacillin. In addition, the pslA gene only existed in biofilm-producing isolates with a frequency of 42.9% (n = 15). The findings of the present study well demonstrated that the P. aeruginosa biofilm-producing isolates were more resistant to the tested antibiotics. Furthermore, because of wide distribution, it seems that the pslA gene is associated with biofilm formation.

Lower respiratory tract infections (LTRIs) are among the most common infectious diseases with potential life-threatening complications. The study consisted of 426 patients with suspected LTRIs from mid and far western region of Nepal between September 2011 and July 2014. The specimens were collected and processed according to the standard microbiological methods at the Central Laboratory of Microbiology of Nepalgunj Medical College, Nepal. Among the isolated Gram-positive organisms, Streptococcus pneumonia (n = 30, 51.7%) was the most predominant pathogen, followed by Staphylococcus aureus (n = 28, 48.3%). Among the isolated Gram-negative organisms, Pseudomonas aeruginosa (n = 71, 35.32%) was the most predominant pathogen, followed by Haemophilus influenzae (n = 68, 33.83%), Klebsiella pneumonia (n = 36, 17.19%), and Escherichia coli (n = 26, 12.94%). The pattern of resistance varied regarding the bacteria species, and there were multi-resistant isolates. Also, a significant difference (P < 0.05) was observed between males and females for each type of bacterial species. Among 259 isolates, 86 (33.20%) were from children aged 1-10 years, which were statistically significant (P < 0.05) compared to the other age groups. P. aeruginosa and H. influenzae (Gram-negative) and S. pnemoniae (Gram-positive) were the most common bacterial isolates recovered from LTRIs. Age group of 1-10 years old was at a higher risk. Many isolates showed appreciable levels of antibiotic resistance due to antibiotic abuse. There is a need to increase surveillance and develop better strategies to curb the increasing prevalence of LRTI in this region of Nepal.