Incidence and molecular characterization of the extended spectrum beta lactamase-producing Escherichia coli isolated from urinary tract infections in Eastern Saudi Arabia

An Overview of Antimicrobial Resistance in Saudi Arabia (2013-2023) and the Need for National Surveillance

Antimicrobial resistance (AMR) is a well-recognized global threat. The World Health Organization (WHO) issued a report ranking the critical types of bacterial resistance that need to be monitored. Several studies from individual institutions in Saudi Arabia have reported rates of antimicrobial resistance using automated methods. However, no national surveillance study has been conducted to date using gold standard methods for antimicrobial susceptibility testing. This review summarizes AMR rates for major bacterial pathogens in Saudi Arabia and provides a justification for the need for a national surveillance project. In Saudi Arabia, AMR rates for both Gram-positive and Gram-negative bacteria are on the rise. Surveillance studies help identify AMR trends and emergence of outbreaks. The WHO has started a program, the Global Antimicrobial Resistance Surveillance System (GLASS), encouraging its member states, including Saudi Arabia, to conduct antimicrobial surveillance studies to estimate AMR rates worldwide. Of the microbiological methods used to test antimicrobial susceptibility, only broth microdilution (BMD) is considered the "gold standard." As AMR studies in Saudi Arabia are sparse, mostly limited to single centers and were conducted using automated methods, a national AMR surveillance project is needed to evaluate the current status and to inform stewardship decisions.

Dissemination of Class A Cephalosporinases and Class D Carbapenemases in Escherichia coli Isolates From a Tertiary Hospital in Sudan

Introduction The high prevalence of urinary tract infections (UTIs) and rising resistance to beta-lactam antibiotics, which is a global therapeutic concern, are caused by Escherichia coli (E. coli) extended-spectrum beta-lactamases (ESBLs) producers. It is unclear how E. coli that produces ESBLs spreads throughout Gezira state, Sudan. The study aimed to evaluate the dissemination of class A and class D resistance genes among E. coli and to recognize the antibacterial activity of the locally used cephalosporins and carbapenems. Methods One hundred and fifteen isolates of uropathogenic E. coli were collected from patients who attended a tertiary hospital. The isolates were identified using colony morphology, gram staining, and biochemical tests and checked for 16S rRNA using PCR. The multidrug-resistant (MDR) testing was conducted using agar disk diffusion. Finally, the class A and D resistance genes were analyzed by multiplex PCR. Results The study enrolled 200 patients with UTIs. E. coli isolates were found in 115 (57.5%) urine specimens examined, and 60 (52.2%) of them produced resistance to most locally used antibiotics. The antibiotic resistance pattern was higher against cefepime (100%), ceftizoxime (90%), cefuroxime (81.7%), and ceftriaxone (81.7%) and had lower activity against meropenem (13.3%). The genotypic characterization of class A cephalosporinases was 85% for blaCTX-M, 70% for blaSHV, and 33.3% for blaTEM, while for class D carbapenemases, it was 10% for both blaOXA-23 and blaOXA-51. Conclusion The considerable antibiotic resistance to the cephalosporins and meropenem and the increased predominance of the blaCTX-M and blaSHV genes are serious concerns for the health authorities. Meropenem could still be used as the drug of choice for ESBL-producing E. coli.

Antimicrobial Resistance and β-Lactamase Production in Clinically Significant Gram-Negative Bacteria Isolated from Hospital and Municipal Wastewater

Hospital and municipal wastewater contribute to the spread of antibiotic-resistant bacteria and genes in the environment. This study aimed to examine the antibiotic resistance and β-lactamase production in clinically significant Gram-negative bacteria isolated from hospital and municipal wastewater. The susceptibility of bacteria to antibiotics was tested using the disk diffusion method, and the presence of extended-spectrum β-lactamases (ESBL) and carbapenemases was determined using an enzyme inhibitor and standard multiplex PCR. Analysis of antimicrobial resistance of total bacterial strains (n = 23) revealed that most of them were resistant to cefotaxime (69.56%), imipenem (43.47%), meropenem (47.82%) and amoxicillin-clavulanate (43.47%), gentamicin (39.13%), cefepime and ciprofloxacin (34.78%), trimethoprim-sulfamethoxazole (30.43%). A total of 8 of 11 phenotypically confirmed isolates were found to have ESBL genes. The blaTEM gene was present in 2 of the isolates, while the blaSHV gene was found in 2 of the isolates. Furthermore, the blaCTX-M gene was found in 3 of the isolates. In one isolate, both the blaTEM and blaSHV genes were identified. Furthermore, of the 9 isolates that have been phenotypically confirmed to have carbapenemase, 3 were confirmed by PCR. Specifically, 2 isolates have the blaOXA-48 type gene and 1 have the blaNDM-1 gene. In conclusion, our investigation shows that there is a significant rate of bacteria that produce ESBL and carbapenemase, which can promote the spread of bacterial resistance. Identifying ESBL and carbapenemase production genes in wastewater samples and their resistance patterns can provide valuable data and guide the development of pathogen management strategies that could potentially help reduce the occurrence of multidrug resistance.

Clinical and cost-effectiveness analysis of carbapenems versus ciprofloxacin in the treatment of urinary tract infections due to extended spectrum β-lactamase-producing Enterobacterales

BACKGROUND

Urinary tract infections (UTIs) are the most common infectious diseases in both hospital and community settings. The management of UTIs caused by extended spectrum β-lactamase-producing Enterobacterales (ESBL-PE) has become more complicated given the limited options of effective antibiotic agents besides the amplification of total healthcare costs.

METHODS

This was a retrospective cohort study conducted among hospitalized patients between January 2018 and March 2020. Adults diagnosed with UTI due to ESBL-PE with at least 2 days of admission were included. Excluded were patients with concomitant infection, polymicrobial UTI, and pregnant women. The primary endpoints were clinical cure and incremental cost-effectiveness ratio (ICER). Clinical cure, hospitalization, and antibiotics costs were considered to evaluate ICER. The secondary endpoints included microbiological eradication, length of stay (LOS), and 30-day readmission.

RESULTS

Of 102 patients, 89 received a carbapenem and 13 received ciprofloxacin. The patients had similar baseline characteristics, including history of hospitalization and UTI within 3 months. No difference was observed in clinical cure rates (86.5% vs. 100%, P = 0.159), microbiological eradication (93.1% vs. 100%, P = 0.639), median LOS (6 days in both groups, P = 0.773), and 30-day readmission rates (41.6% vs. 46.2%, P = 0.755). The ICER of carbapenem to ciprofloxacin was - 7,626.05, indicating that ciprofloxacin was more cost-effective compared with carbapenems.

CONCLUSION

Ciprofloxacin had comparable cure rates with carbapenems, lower risk of 30-day readmission, and was more cost-effective for the treatment of UTI due to ESBL-PE. Therefore, it should be considered as a valuable option if ESBL-PE showed susceptibility to it.

Antimicrobial Susceptibility and Genetic Prevalence of Extended-Spectrum β-Lactamases in Gram-Negative Rods Isolated from Clinical Specimens in Pakistan

The prevalence of extended-spectrum β-lactamase (ESBL) genes has increased remarkably, resulting in multidrug-resistant gram-negative rods (GNRs) in clinical specimens. This cross-sectional study aimed to determine the antimicrobial susceptibility of ESBL-producing GNRs and its correlation with corresponding genes. Two hundred and seventy-two (n = 272) samples were evaluated for the molecular identification of ESBL genes by polymerase chain reaction after confirmation with the modified double-disc synergy test. E. coli 64.0% (n = 174) was the most prevalent ESBL producer, followed by Klebsiella species 27.2% (n = seventy-four), Acinetobacter species 6.6% (n = eighteen) and others 2.2% (n = six). These ESBL-producing isolates showed resistance to β-lactam antibiotics, i.e., sulbactam/cefoperazone (41.5%), piperacillin/tazobactam (39.3%), meropenem (36.0%), imipenem (34.2%) and non- β-lactam antibiotics, i.e., nalidixic acid (89.0%), co-trimoxazole (84.9%), ciprofloxacin (82.4%), gentamicin (46.3%), nitrofurantoin (24.6%), amikacin (19.9%) and fosfomycin (19.9%). The incidences of the ESBLs-producing genes bla_CTX-M, bla_TEM, bla_OXA and bla_SHV were 91.2%, 61.8%, 39.3% and 17.6%, respectively. Among nine multiple-gene combinations, bla_CTX-M + bla_TEM (30.5%) was the most prevalent combination, followed by bla_CTX-M + bla_OXA + bla_TEM (14.0%), bla_CTX-M + bla_OXA (13.6%), bla_CTX-M + bla_TEM + bla_SHV (7.0%), bla_CTX-M + bla_SHV (2.2%), bla_CTX-M + bla_OXA + bla_SHV (2.2%) and bla_OXA + bla_TEM (1.8%). ESBLs producing GNRs carrying bla_CTX-M, bla_TEM, bla_OXA and bla_SHV showed resistances to β-lactam antibiotics, i.e., ampicillin, amoxillin-clavulanic acid, cefotaxime and ceftazidime but were susceptible to carbapenems (meropenem and imipenem), β-lactam-β-lactamase inhibitor combination (piperacillin/tazobactam) and non-β-lactam antibiotics i.e., aminoglycoside (amikacin and gentamicin), nitrofurantoin and fosfomycin. These antibiotics that demonstrated activity may be used to treat infections in clinical settings.

Antibiotic-resistance genes in E. coli strains in GCC countries: A meta-analysis

Background:

Antimicrobial resistance (AMR) in Escherichia coli is an alarming issue worldwide, including in the Gulf Cooperation Council (GCC) countries, yet the prevailing gene patterns have not recently been reviewed. This study was conducted to determine and report on the dominant E. coli antimicrobial resistant gene patterns in GCC countries.

Method:

A scoping review identified the predominant AMR genes in GCC countries: CTX M, TEM, SHV, NDM, OXA, and VIM genes. For the systematic review, two authors independently searched Scopus, PubMed, Google Scholar, Science Direct, and Web of Science for interventional, clinical, or observational studies on the chosen AMR-conferring genes in E. coli published from GCC countries between January 2013 and June 2019, when the last search was carried out. The search strategy followed the PRISMA guidelines. The risk of bias was assessed using a 6-item standardized checklist. Random-effects modeling was used for all analyses.

Results:

A total 32 studies were included in the final synthesis of evidence. Overall, CTX-M (53.8%) was the most prevalent gene in the region followed TEM (40.6%), NDM-1 (28.4%), OXA (24.3%), VIM (8.5%), and SHV (7.8%). Most included studies were from Saudi Arabia: CTX-M was again most common with a prevalence of 46.8% from 5442 isolates.

Conclusion:

The risk of bias analysis showed a mean quality score of 4.25 ± 0.75, indicating high-quality in studies included in this meta-analysis. This review found that CTX-M gene is the most common AMR-conferring gene in E. coli strains from most GCC countries.

Emergence of bla TEM, bla CTX-M, bla SHV and bla OXA genes in multidrug-resistant Enterobacteriaceae and Acinetobacter baumannii in Saudi Arabia

Multidrug-resistant (MDR) patterns due to extended-spectrum β-lactamase (ESBL) production in pathogenic bacteria are now becoming prevalent in hospitals worldwide, posing a public health challenge. The aim of the present study was to determine the antibiotic susceptibility patterns and distribution of the bla _TEM, bla _CTX-M, bla _SHV and bla _OXA ESBL resistance genes in MDREnterobacteriaceae and Acinetobacter baumannii (A. baumannii). A cross-sectional study was conducted between September 2017 and August 2018 in the King Abdullah Hospital (Bisha, Saudi Arabia). Bacterial isolates were collected from the clinical samples of patients; these were identified and screened for ESBL production and their antibiotic susceptibility was examined using standard microbiology methods. Multiplex-PCR runs were performed to identify genes encoding ESBL producers. DNA sequencing analysis was used to identify the specific gene variants. Of the 274 isolates, 173 (63.1%) exhibited MDR patterns to different antibiotics. A. baumannii revealed the highest resistance rates for cefuroxime (100%), gentamicin (88%) and amikacin (86%). Klebsiella pneumoniae (K. pneumoniae) isolates had the highest resistance rates for cefuroxime (98%), aztreonam and trimethoprim/sulfamethoxazole (87% for each). Escherichia coli (E. coli) exhibited high resistance rates for trimethoprim/sulfamethoxazole (92%) and cefuroxime (87%). Of the 173 MDR isolates, 78 (45.1%) exhibited ESBL production. Of these, 88.9% (72/78) carried ESBL genes. The most prevalent gene-encoding isolates were bla _TEM (84.7%), followed by bla _CTX-M (33.3%), bla _SHV (2.7%) and bla _OXA-1 (1.4%). A single bla _TEM gene was predominantly produced by K. pneumoniae (60.7%), A. baumannii (78.9%) and Proteus mirabilis (80%), whereas bla _CTX-M was harbored by E. coli (33.3%). The co-existence of two different genes in a single bacterium was revealed in 22.2% of isolates, commonly between bla _TEM and bla _CTX-M (19.4%). Sequencing analysis revealed that bla _CTX-M-15 and bla _TEM-1 were predominant variants of the bla _CTX-M and bla _TEM genes, respectively. The present study revealed a diversity of ESBL genes in Gram-negative bacterial isolates, with bla _TEM being the most prevalent type. The emergence of various ESBL genes with several co-existing genotypes is alarming, rendering extensive surveillance studies necessary to understand the transmission and epidemiology of such resistant gene-carrying isolates.

"Occurrence of bla CTX-MGp1 and bla CTX-MGp26 in third generation cephalosporin-resistant and carbapenem- resistant bacterial isolates from southwest region of Saudi Arabia-a preliminary study"

This study was intended to identify the genes responsible for ESBL- and carbapenemase-producing bacterial isolates obtained from Jizan region. A hospital-based cross-sectional study was conducted over a period of 3 months (15th November 2018–15th February 2019). Fifty non-duplicate, 3rd-generation cephalosporin and carbapenem-resistant isolates were collected from microbiology lab of a tertiary care hospital in Jizan province and were screened for ESBLs and MBLs by phenotypic methods (CDT). The positive isolates (by phenotypic method) were then scanned for the presence of bla_ESBLs and bla_NDM-₁ genes, respectively, by PCR.

As a result, 10% isolates showed imipenem-cephalosporin co-resistance whereas 92% (46/50) of isolates were found to be ESBL producers by CDT. The maximum occurrence was observed for bla_CTX-M (70%), followed by bla_SHV (16%) and least occurrence was noted for bla_TEM (12%). Moreover, 97% isolates (34/35) were of bla_CTX-MGroup1 but one isolate showed the presence of bla_CTX-M Group26. Despite the co-resistance of cephalosporin and carbapenem, 14% (7/50) were found to be MBL producer on phenotypic detection by Combination Disc Test (CDT), whereas all the isolates were found to be negative for bla_NDM-1. Hence bla_CTX-MGroup1 is present in quite high fraction followed by bla_SHV in the bacterial isolates of Jizan region. Moreover, the occurrence of bla_CTX-M Group1 and bla_CTX-M Group26 in clinical isolates from the Jizan region of Saudi Arabia has been reported for the first time.

Antimicrobial resistance among GLASS pathogens in conflict and non-conflict affected settings in the Middle East: a systematic review

BACKGROUND

In spite of the evident general negative effects of armed conflict on countries' health systems and populations' health outcomes, little is known about similar impacts of conflicts on the spread of antimicrobial resistances (AMR). This review was to address this evidence gap and describe: 1. Patterns of AMR in the Middle East (ME) and resistance profiles of pathogens included in the Global AMR Surveillance System (GLASS) supported by the World Health Organization; 2. Differences in proportions of AMR isolates between conflict and non-conflict countries.

METHODS

A systematic literature review was conducted following PRISMA guidelines and searching five electronic databases. Subject heading and free text were searched for "antimicrobial resistances" and "Middle East", to identify observational studies on AMR published from January 2011 to June 2018. Data were extracted from included articles on a predefined set of variables. Percentages of AMR were analysed as median and interquartile ranges. Risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

A total of 132 articles met the inclusion criteria. Included studies showed heterogeneity in study design, laboratory methods and standards for interpretation of results, and an overall high risk of bias. Main findings were the following: 1. High proportions of carbapenem resistance in Acinetobacter spp. (median 74.2%), and both carbapenem resistance (median 8.1 and 15.4% for E. coli and K. pneumoniae respectively) and ESBL-production (median 32.3 and 27.9% for E. coli and K. pneumoniae respectively) amongst Enterobacteriaceae. S. aureus isolates showed a median methicillin resistance percentage of 45.1%, while vancomycin resistance was almost absent. A median of 50% of the strains of S. pneumoniae showed non-susceptibility to penicillin. 2. Similar trends were observed in conflict and non-conflict affected countries.

CONCLUSIONS

There is a lack of standardization in the methodological approach to AMR research in the Middle East. The proportion of antibiotic resistances among specific GLASS pathogens is high, particularly among Acinetobacter spp.

Emphysematous pyelonephritis and septic shock in an elderly male patient caused by extended-spectrum beta-lactamase producing Klebsiella pneumoniae

Emphysematous Pyelonephritis is a rare necrotizing infection with gas production and a high overall mortality rate.

An elderly diabetic male patient presented to our Emergency Department with septic shock and was found to have left perinephric emphysematous pyelonephritis with a large collection. He was managed with the proper antibiotic therapy, and two trials of percutaneous drainage of the collection with no significant reduction in the size of the abscess. After operative drainage and debridement of multiple pockets, he improved and was discharged home. Extender spectrum beta-lactamase producing organism was an additional challenge in our patient's management.

Retrospective Analysis on Antimicrobial Resistance Trends and Prevalence of β-lactamases in Escherichia coli and ESKAPE Pathogens Isolated from Arabian Patients during 2000-2020

The production of diverse and extended spectrum β-lactamases among Escherichia coli and ESKAPE pathogens is a growing threat to clinicians and public health. We aim to provide a comprehensive analysis of evolving trends of antimicrobial resistance and β-lactamases among E. coli and ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acine to bacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) in the Arabian region. A systematic review was conducted in Medline PubMed on papers published between January 2000 and February 2020 on countries in the Arab region showing different antibiotic resistance among E. coli and ESKAPE pathogens. A total of n = 119,144 clinical isolates were evaluated for antimicrobial resistance in 19 Arab countries. Among these clinical isolates, 74,039 belonged to E. coli and ESKAPE pathogen. Distribution of antibiotic resistance among E. coli and ESKAPE pathogens indicated that E. coli (n = 32,038) was the predominant pathogen followed by K. pneumoniae (n = 17,128), P. aeruginosa (n = 11,074), methicillin-resistant S. aureus (MRSA, n = 4370), A. baumannii (n = 3485) and Enterobacter spp. (n = 1574). There were no reports demonstrating Enterococcus faecium producing β-lactamase. Analyses revealed 19 out of 22 countries reported occurrence of ESBL (Extended-Spectrum β-Lactamase) producing E. coli and ESKAPE pathogens. The present study showed significantly increased resistance rates to various antimicrobial agents over the last 20 years; for instance, cephalosporin resistance increased from 37 to 89.5%, fluoroquinolones from 46.8 to 70.3%, aminoglycosides from 40.2 to 64.4%, mono-bactams from 30.6 to 73.6% and carbapenems from 30.5 to 64.4%. An average of 36.9% of the total isolates were reported to have ESBL phenotype during 2000 to 2020. Molecular analyses showed that among ESBLs and Class A and Class D β-lactamases, bla_CTX-M and bla_OXA have higher prevalence rates of 57% and 52.7%, respectively. Among Class B β-lactamases, few incidences of bla_VIM 27.7% and bla_NDM 26.3% were encountered in the Arab region. Conclusion: This review highlights a significant increase in resistance to various classes of antibiotics, including cephalosporins, β-lactam and β-lactamase inhibitor combinations, carbapenems, aminoglycosides and quinolones among E. coli and ESKAPE pathogens in the Arab region.

Occurrence and Characteristics of the Extended-spectrum Beta-lactamase-producing Enterobacterale in a Hospital Setting

Objectives:

Infectious diseases caused by ESBL-producing Enterobacterale are an emerging problem worldwide, which increase hospital costs, empirical treatment failure, together with rates of morbidity and mortality. The aims of this study were to determine the antibiotic-resistant patterns and the frequency of blaTEM, blaCTX-M and blaSHV genes among Enterobacterale.

Methods:

A total of 239 non-repeated clinical isolates of the Enterobacterale family, including 202 (84.5%) Escherichia coli and Klebsiella pneumoniae 25 (12.3%) were collected. Identification and susceptibility tests were carried out on 60 (25.9%) ESBL phenotypes using biomérieux VITEK® 2 compact system. Isolates showing ESBL positivity by the phenotypic method were all screened for blaTEM, blaCTX-M and blaSHV genes by PCR.

Results:

The prevalence of ESBL-producing Enterobacterale isolates was found to be 25.9%. These ESBL-producing isolates displayed an increasing rate of resistance for aminopenicillins (ampicillin) (96.3%), followed by piperacillin-tazobactam (54.2%), amoxicillin/clavulanic acid (45.8), the cephalosporin groups, ceftriaxone (52.4%), ceftazidime (46.7%), and fluoroquinolone (ciprofloxacin) (42.7%). Both the organisms showed a higher susceptibility to the carbapenems (Imipenem) and aminoglycosides (Amikacin). Out of the 62 ESBL positive isolates, 11 (17.7%) carried the TEM gene, 22 (35.5%) carried the CTX-M gene alone, 8 (12.9%) carried both TEM and CTX-M genes, 1(1.6%) carried both SHV and CTX-M genes, and 20 (32.3%) carried the TEM, SHV, and CTX-M genes. SHV gene alone was not reported in any of the isolates.

Conclusion:

The study indicated a moderate occurrence of ESBL-producing Enterobacterale with CTX-M being the most dominant gene. The co-existence of all three genes on many occasions suggested the carriage of multiple plasmids with three resistance genes that might pose a serious epidemiological, clinical and public health threat.

Multi-Antibiotic Resistance and Factors Affecting Carriage of Extended Spectrum β-Lactamase-Producing Enterobacteriaceae in Pediatric Population of Enugu Metropolis, Nigeria

Extended-spectrum β-lactamase (ESBL)-producing organisms have become a serious challenge in healthcare delivery globally. The prevalence of ESBL carriage in healthy and sick children in Enugu, Nigeria, was bacteriologically investigated in this study. Four hundred and twenty-two biological samples (mid-stream urine and feces) were bacteriologically analyzed. The isolates were screened for ESBL production using Clinical and Laboratory Standards Institute (CLSI) breakpoints. The suspected ESBL producers were confirmed using double disc synergy test method. Out of the 162 isolates screened, 32 (19.8%) were confirmed as ESBL positive, with a prevalence of 25.32% among sick children in Enugu State University Teaching Hospital (ESUTH), Parklane, Enugu and 13.89% in apparently healthy children in a community setting. Klebsiella spp. and Escherichia coli had the highest prevalence of 34.6% and 28.6%, respectively; Citrobacter spp. and Enterobacter spp. were 18.2% and 16.7%, respectively. The ESBL positive isolates were resistant to sulfamethoxazole/trimethoprim (100%), tetracycline (100%), kanamycin (96.9%), nitrofurantoin (84.4%), ciprofloxacin (68.6%), and chloramphenicol (62.5%) but susceptible to meropenem (100%), colistin (56.3%), and gentamicin (50%). Klebsiella spp. had the highest ESBL occurrence among sick children while E. coli had the highest ESBL occurrence among healthy children in Enugu. All ESBL-positive isolates were multiply resistant to conventional antibiotics. The emergence and spread of β-lactamase-producing Enterobacteriaceae in hospital and community environments highlight the possibility for an infection outbreak if not checked.

Risk factors and molecular features of extended-spectrum beta-lactamase producing bacteria at southwest of Saudi Arabia

Objectives:

To explore the risk factors, the prevalence rate, and gene types of extended-spectrum beta-lactamase (ESBL)-producing bacteria as the causative agents of infection at King Abdulaziz Specialist Hospital (KAASH), Taif, Kingdom of Saudi Arabia.

Methods:

This was a retrospective study conducted during the period between February 2017 and January 2018. All samples obtained from the KAASH were analyzed. The MicroScan Walkaway System, bacteriological examination and double disk synergy tests were used to detect ESBL-producing bacteria. To identify ESBL genes, the polymerase chain reaction (PCR) technique was used.

Results:

The ESBL phenotype was detected in 351 of 1151 isolates (30.5%); Escherichia coli (E. coli) (62.7%) and Klebsiella pneumoniae (K. pneumoniae) (23.6%) were the most prevalent. The highest proportion of ESBL specimens was found in urine (62%.5), and these organisms were mainly isolated from the female medical ward (20.2%). Based on the statistical analysis, lung diseases, renal diseases, diabetes and heart diseases contributed to the spread of ESBL infections. Amikacin, imipenem, meropenem and tigecycline were found to be effective in overcoming ESBL infections; however, these antibiotics may be inappropriate for new strains of K.pneumoniae. The distribution of the blaCTX-M gene was high (87%), compared with blaTEM (74.9%) and blaSHV (29.4%).

Conclusion:

These data provide new epidemiological information about the prevalence of ESBL-producing organisms among patients in KAASH, Taif, Saudi Arabia. In addition, this study identified the clonal nature of isolated E.coli and K.pneumoniae.

The genetic background of antibiotic resistance among clinical uropathogenic Escherichia coli strains

The spreading mechanisms of antibiotic resistance are related to many bacterial and environment factors. The overuse of antibiotics is leading to an unceasing emergence of new multidrug resistant strains. This problem also concerns uropathogenic Escherichia coli strains, which is the most common pathogen causing urinary tract infections. The aim of this study was the genetic analysis of antibiotic resistance in comparison to the phenotypic background of E. coli strains. The characterized collection of E. coli strains isolated 10 years ago from the urine samples of patients with urinary tract infections was used for antimicrobial susceptibility testing (the disc diffusion method) and analysis of antibiotic resistance genes (PCR reaction, sequencing). Additionally, the presence of ESBL strains was analyzed. Fourteen genes were associated with resistance to beta-lactams, aminoglycosides, sulfonamides and quinolones. The genetic analysis revealed that bla_TEM-1 and sul2 were present in almost all of the studied strains. Other drug-resistance genes were very rare or non-existent. Otherwise, the phenotypic resistance to fluoroquinolones was well correlated with the genotypic background of the studied bacteria. The presence of particular genes and specific mutations indicate a high bacterial potential to multidrug resistance. On the other hand, it needs to be emphasized that the standard disk diffusion test for the routine antimicrobial susceptibility analysis is still the best way to estimate the current situation of bacterial drug-resistance.

Prevalence and Antibiotic Susceptibility Pattern of Extended Spectrum Beta Lactamases Producing Escherichia Coli Isolated from Outpatients with Urinary Tract Infections in Babol, Northern of Iran

Received 08 November 2017 Accepted 15 February 2018 The incidence of community-acquired UTIs due to extended-spectrum beta-lactamase (ESBL) producing E. coli isolates, has increased worldwide and is considered a great problem in the treatment of infections. The aim of this study was to determine the prevalence of ESBL producing E. coli isolates in urine samples of outpatients in Babol, North of Iran. A total of 3 699 urine samples from outpatients referred to Yahyanejad Hospital, Babol, Iran, were collected during 15 months, from March 2016 to June 2017. The samples were processed for bacterial culture using conventional methods, while antimicrobial susceptibility testing for E. coli isolates was performed by the disc diffusion method. The prevalence of ESBL producing E. coli isolates were assessed by Double-Disc tests. Of 3699 tested sample, 201 samples showed the growth of pathogens and among them, 106 isolates (52/7%) were E. coli. The rate of ESBL producing E. coli isolates was 25/4%.The majority (81/5%) of the isolates were from females. High percent resistance was found against ceftazidime, cefotaxime, ceftriaxone, cefixime and ciprofloxacin, ranging from 61-100%, while the highest percent susceptibility was seen to meropenem, piperacillin- tazobactam (100%), followed by nitrofurantoin and amikacin (91%). The high prevalence of ESBL producing E. coli isolates from outpatients calls for the need to aware of this increasing resistance between uropathogens and update bacterial susceptibility data and to set up our empirical therapy accordingly.