ESBL Positivity Research Articles

Prevalence of Extended-Spectrum ß-Lactamases (ESBLs) and AmpC ß-Lactamases in Clinical Isolates of Multiple Drug-Resistant Escherichia coli

The current study aims to investigate the prevalence of extended-spectrum ß-lactamases (ESBLs) and AmpC β-lactamases in multiple-drug-resistant Escherichia coli (e.g., multidrug-resistant (MDR), extensively drug-resistant (XDR), and pan-drug-resistant (PDR)) collected from hospitalized patients in Baghdad. The results showed that the prevalence of ESBLs among E.coli isolates was high. From the total 113 E.coli isolates, 75 (66.37%) were ESBL-producing, while 38 (33.63%) were non-ESBL-producing. Out of 75 ESBL-positive isolates, 39 (52%) were obtained from females and 36 (48%) from males. Additionally, 43 (57.33%) isolates were collected from urine samples, and the highest production of ESBLs was obtained from the age group 41–60 years (29.33%). Moreover, out of 111 MDR E.coli, 64 (57.66%) exhibited a positive ESBL test, while 47 (42.34%) did not. Out of 24 XDR E.coli isolates, 11 (45.83%) demonstrated positive ESBLs, while 13 (54.17%) showed negative ESBLs. The antimicrobial susceptibility test results showed that positive ESBL E.coli isolates were more drug-resistant than negative ESBL isolates. The positive ESBLs of E.coli exhibited a higher resistance rate to the β-lactam antibiotics and showed a co-resistance to non-β-lactam antibiotics. Phenotypic detection of AmpC β-lactamase by the screening of cefoxitin-resistant isolates revealed that 43 (38.05%) isolates were considered positive for AmpC β-lactamase production. However, the PCR technique gives different results. In conclusion, the prevalence of ESBL and AmpC β-lactamase producing E. coli is rapidly increasing among clinical isolates of MDR, XDR, and possibly PDR E.coli.

Causative Microorganisms in Community-Acquired Urinary Tract Infections and Risk Factors for the Development of Infection with Extended-Spectrum β-Lactamase-Producing Species.

This study aimed to determine the microorganisms grown in the urine cultures of patients followed up with the diagnosis of community-acquired urinary tract infection (CA-UTI), their antibiotic susceptibility, and the risk factors that cause extended-spectrum β-lactamase (ESBL) production in microorganisms. Patients diagnosed with CA-UTI in the Yıldırım Beyazıt University City Hospital Infectious Diseases and Clinical Microbiology Clinic between February 2019 and February 2020 were prospectively analyzed. The microorganisms grown in the urine cultures and antibiotic susceptibility rates were examined. The clinical and demographic characteristics of the patients were compared in terms of the isolated agent producing ESBL. Escherichia coli (63.8%) and Klebsiella pneumoniae (22.0%) were the most common microorganisms detected in the urine cultures; the rate of those producing ESBL was 46.6%. Antibiotics with high resistance rates were ampicillin (74.2%), cefuroxime (49.6%), and ceftriaxone (49%). Male gender, complicating factors, immunosuppression, kidney transplantation and history of antibiotic use were determined as significant risk factors for ESBL production. Male gender, immunosuppression, and history of antibiotic use were also independent risk factors. ROC analysis of risk factors showed ESBL-producing bacteria were isolated at a high rate in patients having ≥3 risk factors. The resistance rates in our study are quite high. Male gender, history of antibiotic use and immunosuppression status were found to be independent risk factors for ESBL positivity in patients with CA-UTI, and the more risk factors a patient has, the higher the risk of ESBL positivity.

Characterization of Extended-Spectrum β-Lactamase-Producing Escherichia coli in Animal Farms in Hunan Province, China.

Multi-drug resistance of bacteria producing extended-spectrum β-lactamase (ESBL) is a public health challenge. Thus, this study aimed to investigate the antimicrobial susceptibility of ESBL-producing Escherichia coli (ESBL-EC) in Hunan Province, China. A total of 1366 fecal samples were collected from pig, chicken, and cattle farms over a six-year period, which were assessed using strain isolation, 16S rRNA identification, polymerase chain reaction, drug sensitivity testing, whole-genome sequencing, and bioinformatics analysis. The results showed an overall prevalence of 6.66% for ESBL-EC strains, with ESBL positivity extents for pigs, chickens, and cattle isolates at 6.77%, 6.54%, and 12.5%, respectively. Most ESBL-EC isolates were resistant to cefotaxime, tetracycline, and trimethoprim-sulfamethoxazole; however, all the isolates were susceptible to meropenem, with relatively low resistance to amikacin and tigecycline. Various multi-locus sequence types with different origins and similar affinities were identified, with ST155 (n = 16) being the most common subtype. Several types of resistance genes were identified among the 91 positive strains, with beta-lactamase blaCTX-M-55 being the most common ESBL genotype. IncFIB was the predominant plasmid type. Widespread use of antibiotics in animal farming may increase antibiotic resistance, posing a serious threat to the health of farmed animals and, thus, to human food security and health.

Clinical characteristics and bacterial culture in complicated appendicitis at Hue University of Medicine and Pharmacy Hospital

Objectives: To evaluate the clinical, laboratory features, bacterial culture outcomes, and antibiotic susceptibilities of these bacteria in intraoperative samples from patients with perforated appendicitis and to establish whether they influence postoperative outcomes. Materials and methods: A descriptive study was conducted on 68 laparoscopic surgery patients from June 2022 to March 2023 at the Digestive Surgery Department, Hue University of Medicine and Pharmacy Hospital. Results: The male/female ratio is 1.2. The mean age was 37.5 ± 25.7. The mean time of the symptom onset was 37.2 ± 29.1 hours; CRP increased in 86.8% of cases. The average postoperative hospital stay was 6.3 ± 2.2 days; Postoperative complications were observed in 20.6%. Peritoneal fluid samples yielded a positive culture in 58 (85.3%); Gram-negative bacteria were isolated in 89.7%; gram-positive bacteria were isolated in 10.3%; polymicrobial growth was observed in 29.4% of the patients. E. coli in 67.6%, P.aeruginosa in 10.3%, Enterobacter spp. in 8.8%, Klebsiella spp. in 4.4%, Citrobacter spp. in 3%; positive ESBL was present in 17 (37%) of the 46 E. coli strains, ESBL was positivity detected in one of Morganerlla morganii strains. In E. coli, ampicillin resistance was 88.6%, amoxicillin-clavulanic acid resistance was 61.5%, and Trimethoprim-sulfamethoxazole resistance was 65%. Conclusion: It is necessary to choose treatment regimens based on local bacteriology and resistance status to optimize empiric empirical postoperative antibiotic regimens. Key words: perforated appendicitis, ESBL, complications, bacteria culture.

Evaluation of three protocols for direct susceptibility testing for gram negative-Enterobacteriaceae from patient samples in Uganda with SMS reporting

In Uganda, the challenge of generating and timely reporting essential antimicrobial resistance (AMR) data has led to overreliance on empirical antibiotic therapy, exacerbating the AMR crisis. To address this issue, this study aimed to adapt a one-step AMR testing protocol alongside an SMS (Short Message Service) result relay system (SRRS), with the potential to reduce the turnaround time for AMR testing and result communication from 4 days or more to 1 day in Ugandan clinical microbiology laboratories. Out of the 377 samples examined, 54 isolates were obtained. Notably, E. coli (61%) and K. pneumoniae (33%) were the most frequently identified, majority testing positive for ESBL. Evaluation of three AMR testing protocols revealed varying sensitivity and specificity, with Protocol A (ChromID ESBL-based) demonstrating high sensitivity (100%) but no calculable specificity, Protocol B (ceftazidime-based) showing high sensitivity (100%) and relatively low specificity (7.1%), and Protocol C (cefotaxime-based) exhibiting high sensitivity (97.8%) but no calculable specificity. ESBL positivity strongly correlated with resistance to specific antibiotics, including cefotaxime, ampicillin, and aztreonam (100%), cefuroxime (96%), ceftriaxone (93%), and trimethoprim sulfamethoxazole (87%). The potential of integrating an SRRS underscored the crucial role this could have in enabling efficient healthcare communication in AMR management. This study underscores the substantial potential of the tested protocols for accurately detecting ESBL production in clinical samples, potentially, providing a critical foundation for predicting and reporting AMR patterns. Although considerations related to specificity warrant careful assessment before widespread clinical adoption.

Efficacy of 1 Versus 3 Days of Intravenous Amikacin as a Prophylaxis for Patients Undergoing Transurethral Resect Prostate: A Prospective Randomized Trail

Background: The goal of the current study was to investigate the safety of a single dose of IV Amikacin given a period of three days as compared to a single dose of one and two days, when used as a surgical prophylactic antibiotic prior to transurethral prostate resection. Study Design: This was a randomized and prospective study conducted at Urology Department of Niazi Medical & Dental College Sargodha for the duration of six-months from May 2022 to October 2022. Methods: There were 300 men who participated in total and had their prostates transurethral resected (TURP). Three groups, A, B, and C, each with 100 participants, were created randomly from among the participants. The participants will either be assigned at random to receive a single dose of Amikacin that complies with recommendations for groups A, B, and C on days 1, 2, and 3. Follow Up until day 30 following surgery, routinely gathered data from TURP will be the end of the study. Within 60 minutes of the incision, all patients received a single dose of prophylactic antibiotics. Results: The Groups A and B had higher rates of significant bacteriuria than Group C, the intention-to-treat analysis determined that this difference was not statistically significant. The results of a per-protocol analysis were similar. (p=0.88; 0.13). This suggests that postoperative bacteriuria poses a significant risk for the emergence of UTI symptoms (p=o.oo2**). Antibacterial drug resistance has a significant relationship with the progression of infectious complications and was associated with a history of diabetes (95% [CI]]: 0.08-3.11, OR=0.33; p=0.01*) and surgical history and ESBL positivity were indicate infection-related issues (95% [CI]: 1.51-1.86, OR=5.1; p=0.023 and 95% [CI]: 2.55-13.1, OR=4.90; p<0.0001***). Conclusions The Amikacin was safe for surgical prophyaxis in single dose until 3 days as compared to 1 and 2 days because of the incidence of postoperative complication such as UTI reduced. It was greater role to decrease antibiotic resistance. Keyword: Bacterial infection, Urinary tract, Antibiotics.

Development of a prediction model for the Acquisition of Extended Spectrum Beta-Lactam Resistant Organisms in U.S. international travellers.

Extended spectrum beta-lactamase producing Enterobacterales (ESBL-PE) present a risk to public health by limiting the efficacy of multiple classes of beta-lactam antibiotics against infection. International travellers may acquire these organisms and identifying individuals at high risk of acquisition could help inform clinical treatment or prevention strategies. We used data collected from a cohort of 528 international travellers enrolled in a multicenter US-based study to derive a clinical prediction rule (CPR) to identify travellers who developed ESBL-PE colonization, defined as those with new ESBL positivity in stool upon return to the United States. To select candidate features, we used data collected from pre-travel and post-travel questionnaires, alongside destination-specific data from external sources. We utilized LASSO regression for feature selection, followed by random forest or logistic regression modelling, to derive a CPR for ESBL acquisition. A CPR using machine learning and logistic regression on ten features has an internally cross-validated area under the receiver operating characteristic curve (cvAUC) of 0.70 (95% confidence interval 0.69-0.71). We also demonstrate that a four feature model performs similarly to the ten feature model, with a cvAUC of 0.68 (95% confidence interval 0.67-0.69). This model uses traveller's diarrhoea, and antibiotics as treatment, destination country waste management rankings, and destination regional probabilities as predictors. We demonstrate that by integrating traveller characteristics with destination-specific data, we could derive a CPR to identify those at highest risk of acquiring ESBL-PE during international travel.

Trends of Antibiotic Resistance in Multidrug-Resistant Pathogens Isolated from Blood Cultures in a Four-Year Period.

Multidrug-resistant organisms cause serious infections with significant morbidity and mortality in the worldwide. These organisms have been identified as urgent and serious threats by CDC. The aim of this study was to determine the prevalence and changes of antibiotic resistance of multidrug-resistant pathogens isolated from blood cultures over a four-year period in a tertiary-care hospital. Blood cultures were incubated in a blood culture system. Positive signalling blood cultures were subcultured on 5% sheep-blood agar. Identification of isolated bacteria was performed using conventional or automated identification systems. Antibiotic susceptibility tests were performed by disc diffusion and/or gradient test methods, if necessary, by automated systems. The CLSI guidelines were used for interpretation of antibiotic susceptibility testing of bacteria. The most frequently isolated Gram-negative bacteria was Escherichia coli (33.4%) followed by Klebsiella pneumoniae (21.5%). ESBL positivity was 47% for E. coli, 66% for K. pneumoniae. Among E. coli, K. pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii isolates, carbapenem resistance was 4%, 41%, 37%, and 62%, respectively. Carbapenem resistance of K. pneumoniae isolates has increased from 25% to 57% over the years, and the highest rate (57%) occured during the pandemic period. It is noteworthy that the aminoglycoside resistance in E. coli isolates gradually increased from 2017 to 2021. The rate of methicillin-resistant S. aureus (MRSA) was found to be 35.5%. Increased carbapenem resistance in K. pneumoniae and A. baumannii isolates is noteworthy, but carbapenem resistance in P. aeruginosa decreased. It is of great importance for each hospital to monitor the increase in resistance in clinically important bacteria, especially isolated from invasive samples, in order to take the necessary precautions in a timely manner. Future studies involving clinical data of patients and bacterial resistance genes are warranted.

Molecular Characterization of Extended Spectrum β-Lactamase Producing Escherichia coli and Klebsiella pneumoniae Isolates and Their Antibiotic Resistance Profile in Health Care-Associated Urinary Tract Infections in North India.

Background Healthcare-associated urinary tract infections (HAUTIs) caused by gram-negative pathogens have emerged as a global concern. So far, little is known about the epidemiology of extended-spectrum β lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae in HAUTIs in India. The study was carried to determine the antibiotic resistance pattern and ESBL-producing genes in E. coli and K. pneumoniae strains isolated from HAUTIs in a tertiary institute in North India. Methods A total of 200 consecutive, nonduplicate clinical isolates of E. coli and 140 isolates of K. pneumoniae from hospitalized patients with UTI were collected during a period of 1 year. Strains were studied for the presence of ESBL genes (blaCTX-M1, blaCTX-M2, blaCTX-M9, blaCTX-M15, blaSHV, blaTEM, blaOXA-1, blaVEB, blaPER-2, and blaGES) by multiplex polymerase chain reaction using gene-specific primers. Results ESBL was detected in 82.5% (165 out of 200) isolates of E. coli and 74.3% (104 out of 140) isolates of K. pneumoniae by phenotypic confirmatory testing. From 269 phenotypically positive ESBL isolates, blaTEM (49.4%) was the most common genotype followed by blaCTX-M1 (31.97%), blaOXA-1 (30.1%), and blaSHV(11.9%) either alone or in combination. In the present study, blaCTX-M-15 (84.89%) was the most common blaCTX-M1-type ESBL. In total, 2.6 and 5.2% of the isolates were positive for PER-2 and VEB genes, respectively. Conclusion To the best of our knowledge, this is the first study on ESBL resistance patterns and ESBL-producing genes in HAUTIs in North India. Our study reports high occurrence with ESBL types CTX-M-1, CTX-M-15, TEM, and SHV. Minor ESBL variants OXA-1, VEB-type, and PER-2-type β-lactamase are also emerging in HAUTIs infections in North India.

The Carrier Rate of Extended Spectrum Beta Lactamase (ESBL) Producing Bacteria in Cockroaches (Periplaneta americana) in Hospital and Community

Highlight :Bacteriologically for colonization of ESBL producing Enterobacteriaceae in cockroaches (Periplaneta americana) were analyzed.The prevalence of ESBL producing bacteria among cockroaches in hospitals is bigger than in households.Abstract: Cockroach (Periplaneta americana) is one of the vectors in the environment that can transmit disease. Cockroaches can act as potential mechanical vectors of antibiotic resistant bacteria. Enterobacteriaceae is a gram-negative bacteria that has natural habitats in the digestive tract of humans and animals. Enterobacteriaceae that produce Extended Spectrum β-lactamases (ESBLs) have emerged as major pathogens in hospitals. The study analyzed the prevalence of ESBL producing bacteria in cockroaches that lived in hospitals and residential homes. In this study, a total of 200 cockroaches consisting of 100 cockroaches from the hospital environment and 100 cockroaches from the residential environment were analyzed bacteriologically for colonization of ESBL producing Enterobacteriaceae. The specimen of the alimentary tract was taken and sub-cultured in MacConkey agar supplemented with cefotaxime 2 ug/ml. Growth colonies were suggested as an ESBL-producing bacteria, then were confirmed as ESBL producers by the Double Disk Synergy Test (DDST). The ESBL gene was detected by Polymerase Chain Reaction (PCR). Among 100 household cockroach samples, 14 (14%) were identified as ESBL producers, while 100 hospital cockroaches were 26 (26%) positive ESBL. The ESBL gene, in hospital cockroach were identified of CTXM 19 (19%), SHV 7 (7%), and not any TEM gene, while among household cockroaches were identified CTXM 2 (2%), SHV 11 (11%), and also not detected TEM ESBL gene. Among ESBL genes, only the CTXM gene was significantly different between household and hospital cockroaches.

Frequency of bla CTX-M and bla TEM Virulence Genes and Antibiotic Resistance Profiles among Klebsiella pneumoniae Isolates in Urinary Tract Infection (UTI) Samples from Hashtgerd, Iran.

Klebsiella pneumoniae (K. pneumoniae) is an opportunistic microorganism and one of the most important causes of urinary tract infection. This study aimed to evaluate the frequency of K. pneumoniae producing broad-spectrum beta-lactamase in urinary tract infection and to determine the pattern of drug resistance. This study was performed on 50 samples of K. pneumoniae isolated from patients with urinary tract infection referred to the Medical Diagnostic Laboratory in Hashtgerd city. The isolates were first evaluated for antibiotic susceptibility by disk diffusion method according to the method proposed by the Clinical and Laboratory Standards Institute (CLSI). Then phenotypic detection of ESBLS was carried out by the DDST method. The frequency of gene bla TEM and bla CTX-M was determined by PCR. The highest resistance was observed to ampicillin (94%) and the highest sensitivity was observed to gentamicin (84%). 22 isolates (44%) were positive for ESBLs production. Of the 50 isolates studied, 34% had bla CTX-M and 28% had bla TEM and 11 (22%) had both genes simultaneously. Also, more than 77% of positive ESBLs isolates had the bla CTX-M gene and approximately 63.64% of positive ESBLs isolates had the bla TEM gene. Given the high prevalence of antibiotic-resistant and ESBL-producing isolates, early identification of these resistant isolates and their follow-up is essential to prevent further outbreaks. It is also important to use appropriate therapeutic strategies and proper and rational administration of antibiotics by physicians.

High prevalence of extended-spectrum beta-lactamase organisms and the COVID-19 pandemic impact on donor recruitment for fecal microbiota transplantation in HongKong.

BackgroundWith increasing number of clinical trials relating to fecal microbiota transplantation (FMT), it is crucial to identify and recruit long‐term, healthy, and regular fecal donors.ObjectiveWe aimed to report the outcomes of screening and recruitment of fecal donors for FMT.MethodsPotential donors were recruited via advertisement through internal mass emails at a university. They were required to undergo a pre‐screening telephone interview, a detailed questionnaire, followed by blood and stool investigations.ResultsFrom January 2017 to December 2020, 119 potential donors were assessed with 75 failed pre‐screening. Reasons for failure included: inability to come back for regular and long‐term donation (n = 19), high body mass index (n = 17), underlying chronic illness or on long‐term medications (n = 11), being healthcare professionals (n = 10), use of antibiotics within 3 months (n = 5) and others (n = 13). Forty‐four donors completed questionnaires and 11 did not fulfill the clinical criteria. Of the remaining 33 potential donors who had stool and blood tests, 21 failed stool investigations (19 extended‐spectrum beta‐lactamase [ESBL] organisms, one Clostridioides difficile, one C. difficile plus Methicillin Resistant Staphylococcus aureus), one failed blood tests (high serum alkaline phosphatase level), one required long‐term medication and nine withdrew consent and/or lost to follow‐up. In total, only one out of 119 (0.8%) potential donors was successfully recruited as a regular donor.ConclusionThere was a high failure rate in donor screening for FMT. Main reasons for screening failure included high prevalence of positive ESBL organisms in stool and failed commitment to regular stool donation.

Plasmid Carriage and ESBL Production among Salmonella Enterica Serovar Typhi from Some Parts of Adamawa State, Nigeria

Effective treatment of typhoid fever caused by Salmonella enterica serovar Typhi has been hampered by the emergence of multidrug resistant and extended spectrum beta lactamase producing strains thus making the organism an important public health pathogen especially in developing countries. This study was aimed at screening Salmonella ser. Typhi isolates from suspected enteric fever patients for the presence of plasmids as well as ESBL production. Eightyfour (84) Salmonella ser. Typhi isolates were obtained from blood and stool culture giving a prevalence of 17.5%. Results of susceptibility screening revealed that 37.5% of the isolates demonstrated ability to produce extended spectrum beta lactamase in vitro out which 37.5% were isolates from Yola while 40% were isolates recovered from Gombi. Furthermore, 41(48.8 %) of the isolates from this study bore plasmids out of which 25(47.1 %) were from Yola metropolis while 13 (41.9 %) were from Gombi Local Government Area. The most common antibiotic resistant marker borne on the plasmids carried by S. ser. Typhi in the study area was resistance to AmpC Co (20) followed by resistance gene for ceftriaxone 10. Screening of the isolates for extended spectrum beta lactamase activity using the double disk synergy test revealed that 9 isolates namely; Salmonella ser. Typhi isolates GMB1, 6, 13, 26 and Salmonella ser. Typhi YLA 4, 11, 22, 31 and 42 showed positive ESBL activity. The PCR analysis revealed the presence of Blactx gene cluster in 4/25 (16%) of S. Typhi isolates. The detection of some strains with resistance to ceftriaxone as well as ability to produce the ESBL is an early warning sign indicating the need for more controlled use of this drug in the country especially in the study area. Keywords: Plasmid, Resistance, ESBL

Impact of ESBL‑producing bacteria on patients with acute pyelonephritis: A study based on patient data from a single hospital

The present study investigated the microbial etiologies and clinical impact of extended‑spectrum β‑lactamase (ESBL)‑producing bacteria according to urine and blood cultures from patients with acute pyelonephritis (APN). Data of all patients (age >15 years) who had been hospitalized at a single hospital with APN were collected between January, 2010 and December, 2018. Overall, 882 patients with APN were included. Patients were divided into an ESBL‑producing and non‑ESBL‑producing group. In addition, each group was further stratified in accordance with positive ESBL cultures from a urine sample (U‑ESBL group and U‑non‑ESBL group) or from either blood or urine samples (UB‑ESBL group and UB‑non‑ESBL group). In 651 (74%) of these cases, bacteria were isolated from either urine or blood samples. The prevalence of ESBL‑producing bacteria from either urine or blood samples (UB‑ESBL) was found to steadily increase over the 9‑year study period from 6.3 to 37.8%. The male sex [odds ratio (OR), 2.572; 95% confidence interval (CI), 1.295‑5.108] and previous antibiotic exposure (OR, 2.275; 95% CI, 1.105‑4.680) were significant risk factors for UB‑ESBL in the multivariable analysis. The patients in the UB‑ESBL group exhibited a significantly higher mortality rate (OR, 1.654; 95% CI, 1.106‑2.474) and a higher continuous renal replacement therapy (CRRT) rate. By multivariable analysis, UB‑ESBL and not U‑ESBL was an independent prognostic indicator for mortality and recurrence. Consequently, the use of carbapenems as a first‑line therapy for APN is expected to rapidly increase, and there is concern regarding the emergence of new antibiotic‑resistance bacteria. Global efforts to reduce resistance bacteria and the development of novel treatment methods other than the use of antibiotics to treat bacteria are urgently required. In addition, the results of the present study emphasize the importance of blood culture tests, as well as urine culture tests for the successful treatment of APN.

Evaluation of clinical, etiological and antimicrobial resistance profile of pediatric urinary tract infections in a secondary health care centre.

Urinary tract infections are common during childhood. The etiologic agents and empirical antibiotics may vary due to age and geographic area. This study was designed to investigate the urinary tract infection pathogens, their antibiotic resistance profile and risk factors in a sample of well-child population. This retrospective study was conducted in the pediatric clinics of a secondary health-care centre in a one-year period. The source of data was hospital and laboratory records. Toilet trained children and adolescents aged between 5-17 years old with positive urine culture were enrolled into the study. Microbiological studies were conducted according to international guidelines. During the study 3640 urine samples were analyzed and 342(9.4%) had significant growth. Gram negative enterobacteria were the most common infectious agents. Antibiotic susceptibility tests showed low cephalosporine resistance unless ESBL was positive. Multi drug resistance was remarkable. Extended beta lactamase resistance rate was 17%. Previous history of antibiotic use before the present administration was the only significant risk factor for ESBL positivity. Treating urinary tract infections may become an emerging problem soon. Unless there are risk factors, cephalosporines are good options, but if so nitrofurantoin or carbapanems should be preferred for treatment in this population.

Klebsiella pneumoniae Suşlarında OXA-48 ve Alt Türevlerinin Araştırılması ve Fenotipik Yansıma

The number of infections caused by carbapenem-resistant Gram negative bacteria is increasing among nosocomial infections. These bacteria are a serious threat to health because they are usually resistant to other antibiotics. This study was aimed to determine the carbapenemase resistance of OXA-48 and its subderivatives in Klebsiella pneumoniae isolates isolated from various clinical samples by phenotypic and genotypic methods and to investigate the presence of OXA-48 gene region genotypically in isolates without resistance. A total of 127 K.pneumoniae strains isolated from patients treated in various clinics and intensive care units were included in this study from March 2015 to March 2016. The isolates were identified and susceptibilities were tested using BD Phoenix automated system and also with Kirby-Bauer disk diffusion method. The presence of resistance was examined phenotypically with the disk of temosillin, which is considered to indicate the presence of OXA-48 type enzymes. The presence of OXA-48 type enzyme was investigated by “in-house” polymerase chain reaction (PCR) in all isolates and the presence of OXA-48 variant was investigated by DNA sequencing analysis on positive isolates. Carbapenem resistance rate was 35 % and ESBL positivity was determined as 46 %. The sensitivity of temocillin disk method in the identification of OXA-48 gene presence in K. pneumoniae strains was found to be 88 %, and specificity 89 %. Ertapenem was the best carbapenem with sensitivity and specificity balance to detect carbapenem resistance caused by OXA-48. The presence of blaOXA-48 gene region was 80 % in K. pneumoniae isolates detected as resistant to carbapenems by an automated system. All sequences obtained by DNA sequence analysis of 42 OXA-48 positive isolates were OXA-48 and there was no variant OXA-48 gene among the sequences. It was observed that the phenotypic reflection of resistance did not occur immediately in three isolates genotypically having OXA-48 gene region. The presence of blaOXA-48 gene region in carbapenems-resistant K.pneumoniae isolates is common. In addition, in some isolates having OXA-48 gene region, should be kept in mind in patients who do not recover despite treatment, due to phenotypic reflection of resistance does not occur immediately

838. Drivers of empiric carbapenem use: How important is history of extended-spectrum beta-lactamase (ESBL) infection?

BackgroundCARs are first line agents for serious infections caused by ESBL producers. Likelihood of developing subsequent ESBL infection is unknown. In patients (pts) with a history (hx) of ESBL positive (ESBLP) culture, empiric therapy with a CAR has become common in hospitals. The purpose of this study was to evaluate the microbiology of subsequent infections (SI) among pts with hx of ESBLP culture and determine risk factors associated with ESBLP SI that may justify an empiric CAR.MethodsThis retrospective observational study was conducted at a multicenter health system. The electronic medical record (EMR) was used to generate a report of all E. coli (EC) or K. pneumoniae (KP) ESBLP cultures during 2017, an analogous report was generated for ESBL-negative (ESBLN) EC or KP. These were termed index cultures (IC). Pts were randomly selected from each report until 200 total pts were enrolled. Inpatients, outpatients, and all culture specimens were included. Pts with an ESBLP culture prior to 2017 were excluded. The EMR was reviewed up to 1 year after the IC. Pt and culture characteristics were recorded. The primary outcome was proportion of pts who developed an ESBLP SI. Risk factors associated with ESBLP SI were determined. Relapsed infection (same site, same bacteria) that occurred within 2 weeks of the IC was excluded.Results200 pts were included, 100 with ESBLP IC and 100 with ESBLN IC. The mean age was 58 years, 84% were female, and 69% were outpatients. 86% of IC were EC and 86% were urine specimens. Within 1 year of IC, 100 pts (50%) developed a SI. 22 of these were ESBLP, 43 were ESBLN, and 35 had no or negative culture. The mean time since IC for ESBLP SI and ESBLN SI was 85 (26-226) days and 140 (15-363) days, respectively (p=0.014). When comparing time to SI, 21 (96%) ESBLP and 26 (61%) ESBLN occurred < 6 months after IC (p=0.003). Among SI with culture data (n= 65), the number of ESBLP SI was higher if the IC was ESBLP (22 vs 0, p< 0.001). Incidence of ESBLP or ESBLN SI in all pts with an ESBLP IC was similar (22 vs 18, p=0.428). Factors associated with ESBLP SI were hx of ESBLP IC, male gender, and time between IC and SI.Table 1. Index Culture Characteristics of Culture Positive Subsequent Infections Figure 1. Cumulative rate of ESBL-positive SI in 180 days (6 months) following IC Table 2. Univariate Analysis of Patient Characteristics Comparing ESBL-positive and ESBL-negative Culture Positive Subsequent Infections ConclusionHx of positive culture for ESBL-producing EC or KP is associated with SI caused by ESBLP EC or KP. Pts presenting < 6 months after ESBLP IC are at increased risk for ESBLP SI, justifying empiric CAR therapy.Disclosures Tyler J. Stone, PharmD, Paratek (Research Grant or Support) Elizabeth Palavecino, MD, Paratek (Grant/Research Support)Paratek (Grant/Research Support) John Williamson, PharmD, Paratek (Research Grant or Support)

Phenotypic and genotypic characterization of multidrug-resistant Acinetobacter baumannii isolated in Algerian hospitals.

The aim of this study was to investigate the drug-resistance and the molecular characterization of carbapenemases, ESBL, and aminoglycoside-modifying enzymes among Acinetobacter baumannii clinical isolates in Algerian hospitals. A total of 92 A. baumannii isolates were collected between 2012 and 2016. Antimicrobial susceptibility testings were performed for β-lactams, aminoglycosides, fluoroquinolones, trimethoprim-sulfamethoxazole, rifampicin and colistin. The phenotypic characterization of β-lactamases was investigated. For 30 randomly targeted strains, the carriage of the carbapenemases, ESBL and aminoglycoside-modifying enzymes -encoding genes was determined by PCR. Sequencing was carried out for carbapenemases and ESBL genes. Most of the 92 isolates studied were recovered from hospitalized patients (93.5%) and were mainly from intensive care units (51.1%) and orthopedics (19.6%). The strains were collected primarily from low respiratory tract (33.7%), wounds (23.9%) and urine (16.3%). Multidrug-resistant A. baumannii strains were prevalent (96.7%). High rates of resistance were observed for almost all antibiotics tested (>70%) excluding rifampicin (7.6%) and colistin (5.4%). For the five colistin-resistant strains, MICs ranged between 4 and 128 µg/mL. Positive MBL (83.7%) and ESBL (23.9%) strains were identified. Regarding β-lactams, the blaNDM and both blaSHV and blaCTX-M1 genes were detected in five and two strains respectively. Sequencing of the genes revealed the presence of blaNDM-1, blaCTX-M-15, and blaSHV-33. For aminoglycosides, aac(6')-Ib, ant(2'')-I and aph(3')-VI genes were detected in three, seven and six strains respectively. Here, we report the first co-occurrence of extended-spectrum β-lactamases SHV-33 and CTX-M-15, the carbapenemase NDM-1 and the emergence of colistin-resistant A. baumannii in Algerian hospitals.

1612. Evaluation of the Use of Ceftolozane/Tazobactam for the Treatment of ESBL-producing Enterobacterales Infections Using International Data from SPECTRA (Study of Prescribing Patterns and Effectiveness of Ceftolozane/Tazobactam Real World Analysis)

BackgroundThere is a paucity of data on outcomes of patients with severe ESBL-producing Enterobacterales infections treated with empiric or directed ceftolozane/tazobactam (C/T). This study looked at the treatment patterns and outcomes associated with C/T use in the treatment of ESBL-producing Enterobacterales.MethodsData were collected from an international cohort of 32 hospitals in 6 countries as part of SPECTRA, a retrospective multicenter database of C/T use globally, from 2016 – 2019. All adult patients with an ESBL positive Enterobacterales sterile site culture and treated with ≥ 48 hours of C/T were eligible. Outcomes assessed were clinical success, 30-day mortality from index event and readmission.ResultsThere were 59 patients with 121 ESBL positive isolates. Blood and urine were the most common sites of infection at 19.8% each, followed by respiratory (18.2%). E. coli (50%) and K. pneumoniae (30%) were the most common pathogens. On average patients had 2 positive ESBL isolates; median 1; range 1-15. Most patients had the same infection site and ESBL pathogen, however 13 had multi-site ESBL pathogens identified and only 2 had polymicrobial ESBL pathogens. Septic shock was observed in 14 (24%) patients; 29 (49%) were in the ICU at the onset of infection. The most common comorbid conditions were immunocompromised hosts (37%) and cardiac disease (32%). 29% of patients were transplant recipients, and 28% had a CrCl < 50 ml/min. In most patients (71%), C/T was given as directed therapy (i.e., once culture results were available). C/T was given prior to culture results (i.e., as empiric therapy) in 17 (29%) patients, of which 77% had clinical success. C/T dose was 1.5 g in 49%. Only 2 of 10 patients with a respiratory source received the currently licensed 3 g dose. Overall, clinical success was observed in 36 (61%) patients. 30-day mortality was 12%. Readmissions occurred in 5%, of which 2 were infection related.ConclusionThe role of newer non-carbapenem antibiotics in the treatment of severe ESBL infections is currently undefined. In a multinational patient database, C/T was found to be effective in severe infections caused by ESBL-producing Enterobacterales. Prospective studies are needed to further define the role of C/T in the setting of frequent drug-resistant Gram-negative pathogens.DisclosuresLaura A. Puzniak, PhD, Merck (Employee) Matteo Bassetti, MD, Shionogi Inc. (Advisor or Review Panel member) Pamela Moise, PharmD, Merck & Co., Inc. (Employee, Shareholder) David Paterson, Accelerate (Speaker’s Bureau)BioMerieux (Speaker’s Bureau)BioMerieux (Advisor or Review Panel member)Entasis (Advisor or Review Panel member)Merck (Advisor or Review Panel member)Merck (Grant/Research Support)Merck (Speaker’s Bureau)Pfizer (Speaker’s Bureau)Shionogi & Co., Ltd. (Grant/Research Support)VenatoRx (Advisor or Review Panel member)

Phenotypic detection of ESBL among E.coli and Klebiella pneumoniae by modified CLSI guidelines

Introduction: Escherichia coli and Klebsiella pneumoniae cause a wide range of infections. Multidrug-resistance strains carrying resistance genes have become a growing problem worldwide. The ESBLs have emerged distinctly, especially in Escherichia coli and Klebsiella pneumoniae. Material and Methods: 250 non repetitive isolates of E. coli and K. pneumoniae were isolated from different clinical samples (pus, urine, sputum, blood) for the study. Each isolate was tested for production of ESBL by CLSI recommended PCT and compared with Modified CLSI Method for ESBL detection. Results: 133 E. coli and 117 K. pneumoniae were isolated where 65.2% of ESBL were detected. With modified CLSI method, overall rate of ESBL positivity increased from 65.2% to 74.4%.of E. coli and 74.3% of K. pneumoniae isolates were ESBL producers by modified CSLI Method. Conclusion: All the clinical samples growing gram negative bacteria should be tested for ESBL, production. Considering the grave scenario of antibiotic resistance in our country, it is high time that all clinical laboratories start detecting these enzymes routinely and accurately. Keywords: Escherichia coli, Klebsiella pneumoniae, ESBL, Modified CLSI guidelines.