Resistant Enterobacteriaceae Research Articles

Antibiotic Susceptibility Patterns for Carbapenem-Resistant Enterobacteriaceae.

Carbapenem is a broad-spectrum beta-lactam antibiotic considered the last choice for the treatment of antibiotic-resistant Gram-negative bacteria. Thus, the increasing rate of carbapenem resistance (CR) in Enterobacteriaceae is an urgent public health threat. This study aimed to evaluate the antibiotic susceptibility pattern of carbapenem-resistant Enterobacteriaceae (CRE) to new and old antibiotics. In this study, Klebsiella pneumoniae, E. coli, and Enterobacter spp. were collected from 10 hospitals in Iran for one year. CRE is recognized by resistance to meropenem and/or imipenem disk after identification of the collected bacteria. Antibiotic susceptibility of CRE against fosfomycin, rifampin, metronidazole, tigecycline, and aztreonam was detected by disk diffusion method and colistin by MIC. In this study, 1222 E. coli, 696 K. pneumoniae, and 621 Enterobacter spp. were collected from 10 hospitals in Iran in one year. Fifty-four E. coli (4.4%), 84 K. pneumoniae (12%), and 51 Enterobacter spp. (8.2%) were CRE. All CRE strains were resistant to metronidazole and rifampicin. Tigecycline has the highest sensitivity on CRE and levofloxacin for Enterobacter spp. Tigecycline showed an acceptable effectiveness rate of sensitivity on the CRE strain. Therefore, we suggest that clinicians consider this valuable antibiotic to treat CRE.

Occurrence and characteristics of extended-spectrum-β-lactamase producing Escherichia coli (blaTEM-128) isolated from Mus musculus captured from a veterinary clinic and houses in Tunis, Tunisia

Antimicrobial resistance in Enterobacteriaceae is a public health problem. Rodents, can be a potential vector for transmission of multidrug resistant bacteria between animals, humans, and environment. The aim of our study was to assess the level of Enterobacteriaceae present in the intestines of rats collected from different locations in Tunisia, then to determine their antimicrobial susceptibility profiles, to screen extended spectrum β-lactamases-producing strains and determine the molecular mechanism of β-lactams resistance.Between July 2017 and June 2018, 55 strains of Enterobacteriaceae were isolated from 71 rats captured in various locations in Tunisia. Antibiotic susceptibility testing was performed using the disc diffusion method. Genes encoding ESBL and mcr genes were investigated by RT-PCR, standard PCR and sequencing when these genes were found.Fifty-five strains of Enterobacteriaceae were identified. The overall prevalence of ESBL production found in our study was 12.7 % (7/55) of which two E. coli strains were DDST positive, one isolated from a house-caught rat and one from the veterinary clinic and harbored the blaTEM-128 gene. In addition, the other five strains were DDST negative and harbored the blaTEM gene, including three strains isolated from collective restaurant (n = 2: blaTEM-163; n = 1: blaTEM-1), one strain isolated from the veterinary clinic (blaTEM-82), and one strain isolated from a house (blaTEM-128).The results of our study suggest that rodents may play a role in the spread of antimicrobial resistant E. coli, highlighting the need to protect the environment and monitor antimicrobial resistant bacteria in rodents to prevent their spread to other wildlife and humans.

Evaluation of Polymyxin NP Test as a Rapid Method for Detection of Polymyxins Resistance in Enterobacteriaceae ‎

Evaluation of Polymyxin NP Test as a Rapid Method for Detection of Polymyxins Resistance in Enterobacteriaceae ‎

Network of Interaction among Enterobacter Species and Klebsiella Pneumonia Clinical Isolates and the Antibiotic Resistance Pattern at Cape Coast

Introduction: Urgent surveillance is required to provide the needed information for the containment of multidrug-resistant (MDR) Enterobacteriaceae. The objective was to examine the antibiotic-resistant patterns among the clinically isolated Enterobacter species and Klebsiella pneumonia from the outpatient department of the University of Cape Coast from 2014 to 2020. Methodology: The cultured isolates were Gram-stained for morphological and biochemical tests. Antibiotic susceptibility tests for the K. pneumonia and Enterobacter spp were done using the modified Kirby-Bauer diffusion technique. A double-disk synergy antibiotic test using cefotaxime, amoxicillin/clavulanic acid and ceftazidime antibiotic test was used to identify extended-spectrum beta-lactase (ESBL) and MDR among the isolates. The network of interactions between bacteria isolates and resistant types and the pattern of interaction of K. pneumonia (in the resistant-10 group) and Enterobacter spp (resistant-12) and the various antibiotics tested was performed using Cytoscape version 3.8.2 software. The data are presented in percentage and statistical significance between MDR and extensively drug-resistant (XDR) compared with Chi-square test. Results: K. pneumonia formed a clustering network with other bacteria isolates around resistant type 10 (resistant-10) and Enterobacter spp around resistant type 12 (resistant-12). The interactions (edges) of bacteria isolates and resistant types (nodes) were unique for Staphylococcus saprophyticus with Proteus mirabilis which exhibited two patterns of interactions (resistant-10 and resistant-12), connecting the two resistant types among the bacteria isolates. The interactive network patterns of Enterobacter spp and the various antibiotics were different from the interaction patterns for K. pneumonia. The K. pneumonia isolates were highly resistant to cefuroxime 2/3 (66.67%) and ampicillin 2/3 (66.67%) in the year 2020. Enterobacter spp on the other hand were highly resistant to tetracycline 16/20 (80.00%) in 2014 and ceftriaxone 5/9 (55.56%), levofloxacin 5/9 (55.56%), ceftazidime 5/9 (55.56%) and gentamycin 5/9 (55.56%) in 2020. Chi-square analysis showed a highly significant difference of χ2 = 11.87, p=0.0006 and χ2 = 7.789, p=0.0053 between MDR and XDR Enterobacter spp isolates in 2014 and 2020, respectively. Conclusion: Early detection, constant monitoring and control practices and policies that prevent the misuse or overuse of these antibiotics are required to slow down the rapid development of resistance to Enterobacter spp and K. pneumonia in Cape Coast.

Risk factors and molecular epidemiology of fecal carriage of carbapenem resistant Enterobacteriaceae in patients with liver disease

BackgroundCarbapenem resistant Enterobacteriaceae (CRE) colonization is a risk factor for CRE infection. CRE infection results in an increase in mortality in patients with cirrhosis. However, minimal data regarding the prevalence and the risk factors of CRE colonization in patients with liver disease yet without liver transplantation are available. The present study aimed to investigate the prevalence, risk factors and molecular epidemiology characteristics of CRE fecal carriage among patients with liver disease.MethodsStool specimens from 574 adult inpatients with liver disease were collected from December 2020 to April 2021. CRE were screened using selective chromogenic agar medium and identified by the Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS). Antimicrobial susceptibility was determined using the broth microdilution method. Carbapenemase genes were characterized by polymerase chain reaction (PCR) and DNA sequencing. Multilocus sequence typing (MLST) was performed for Carbapenem Resistant Klebsiella pneumoniae (CR-KPN) isolates and Carbapenem Resistant Escherichia Coli (CR-ECO) isolates.ResultsThe total number of stool specimens (732) were collected from 574 patients with liver disease. 43 non-duplicated CRE strains were isolated from 39 patients with a carriage rate of 6.79% (39/574). The carriage rate was 15.60% (17/109) in patients with acute-on-chronic liver failure (ACLF). Multivariate analysis indicated that ACLF (P = 0.018), the history of pulmonary infection within past 3 months (P = 0.001) and the use of third generation cephalosporin/β-lactamases inhibitor within past 3 months (P = 0.000) were independent risk factors of CRE colonization in patients with liver disease. Klebsiella Pnuemoniae (KPN) (51.28%) and Escherichia coli (ECO) (30.77%) were main strains in these patients. All CRE strains showed high resistance to most antimicrobials except for polymyxin B and tigecycline. Most (83.72%, 36/43) of the CRE carried carbapenemase genes. blaKPC-2 was the major carbapenemase gene. The molecular epidemiology of KPN were dominated by ST11, while the STs of ECO were scattered.ConclusionsThe present study revealed that CRE fecal carriage rates were higher in patients with ACLF than in patients without liver failure. ACLF, the history of pulmonary infection within past 3 months and the use of third generation cephalosporin/β-lactamases inhibitor within past 3 months were independent risk factors of CRE colonization in patients with liver disease. Regular CRE screening for hospitalized patients with liver disease should be conducted to limit the spread of CRE strain.

Rising Resistance In Uropathogens With An Indication Of Nitrofurantoin Mic Creep.

The irrational use of antibiotics has led to the emergence of multi drug resistant pathogens. The phenomenon of MIC creeps occurs when organisms start showing raised MIC but within susceptible range giving an indication of the prevalence of rise in resistant pathogens in an area. A cross sectional study in a large tertiary care hospital in North India to observe the susceptibility pattern among uropathogens and the possibility of MIC creeps. The Antimicrobial Susceptibility Testing (AST) and Minimum Inhibitory Concentration (MIC) were conducted by Vitek Compact 2. The identification of Extended Spectrum Beta Lactamase (ESBL) producers and Carbapenem Resistant Enterobacteriaceae (CRE) among Escherichia coli were noted. The MIC 50 and MIC 90 for Nitrofurantoin, the most widely used antibiotic for lower UTI, was calculated to investigate the phenomenon of MIC creep. In our study, a total of 2522 urine samples were analyzed: 1538 (61%) were positive with the commonest isolate being E. coli (n=736, 47.8%) followed by Klebsiella spp. (n=178, 11%). Less than 10% of resistance was observed for Fosfomycin, Amikacin, Nitrofurantoin, Imipenem, Meropenem and Colistin. ESBL producers and CRE E. coli were 528 (72% of 736) and 79 (11% of 736) respectively. Overall, 119/736 samples had an MIC ≥128. Amongst the ESBL producers, 96/528 had MIC ≥128 and amongst the CRE, 13/79 had MIC ≥128. E. coli can be used to reflect the trends in development of resistance. In the current study, it was observed that E. coli showed a reduced susceptibility for Nitrofurantoin indicated by a creeping increase in MIC albeit within normal range. Trends in rising MIC should alert prescribers to use drugs such as Nitrofurantoin judiciously. Antimicrobial stewardship practices should be strongly implemented in hospitals to curb rising resistance and obtain better treatment outcomes for patients with infectious diseases.

Detection and correlation of antimicrobial resistance pattern in Enterobacteriaceae from UTI patients in GMERS Medical College, Gujarat

Background: Bacterial resistance to antibiotics is a growing public health threat worldwide. The increasing rate of antimicrobial resistance among bacterial pathogens causing both hospital- and community-acquired infections is a serious threat to public health world-wide. This inappropriate and non-judicious usage of antibiotics has resulted in the development of worldwide antibiotic resistance in bacteria, leading to the emergence of multi-resistant strains of bacterial pathogens. This study focuses on the prevalence of antibiotic resistance in the Enterobacteriaceae group of organisms in urine samples and also detects various methods of antibiotic resistance. Antibiotic resistance detection may be useful for epidemiological and research purposes, as well as for preventing the spread of drug-resistant organisms within hospitals through good infection control practices. Aims and Objectives: The aim of the study was to detect occurrence of β-lactamases, extended-spectrum beta-lactamases (ESBL) and Carbapenemase by phenotypic methods in Enterobacteriaceae from urine samples along with pattern of antibiotic resistance for various antibiotics in them. Materials and Methods: A descriptive study was conducted at a tertiary-care hospital. Testing of ESBL and carbapenemase production detection done according to CLSI (M100) guideline by the Kirby-Bauer disk diffusion method, combination disc diffusion test, and modified Carbapenem inactivation method. Results: A total of 220 Enterobacteriaceae organisms were isolated from processed urine samples of tertiary care Hospitals. Rate of cephalosporin resistance in ESBL and carbapenem-resistant Enterobacteriaceae (CRE) is more than 90% while in non-ESBL more than 70% and in non-CRE 75–80%. Carbapenem resistance in ESBL and non-ESBL is the same. Resistance to fluoroquinolone group, Aminoglycoside group, and Cotrimoxazole and Tetracycline group of antibiotics were more noticed in ESBL and carbapenemase producing organisms. In our study, fosfomycin and Nitrofurantoin are effective treatment in case of ESBL and CRE producing organism. Conclusion: The ESBL and Carbapenemase producing isolates were multi-drug resistant making therapeutic choices limited. Fosfomycin and Nitrofurantoin are effective treatment in multidrug resistance urinary tract infection.

Risk factors for extended-spectrum beta-lactamase- and carbapenem- resistant Enterobacteriaceae in patients with urinary tract infection from a tertiary care hospital

Background: Urinary tract infection (UTI) is a common health problem in both community and nosocomial settings. However, the predisposing factors which are responsible for production of extended spectrum beta-lactamase (ESBL) and carbapenem-resistant Enterobacteriaceae makes the treatment option narrow and cause multidrug resistance. Aim and Objectives: This study demonstrate various risk factors associated with multidrug resistance in Enterobacteriaceae from UTI at tertiary care center in Gujarat. Material and Methods: A retrospective observational study was conducted at a tertiary-care hospital. Urine samples were received from various departments and outpatient department (OPD). Organisms from Enterobacteriaceae group were isolated and identified by various biochemical methods. ESBL and Carbapenemase producing organisms were then processed for Antibiotic susceptibility test as per CLSI guideline. Results: A total of 196 Enterobacteriaceae organisms were isolated from processed urine samples of tertiary care Hospitals. The most prevalent in people aged 45–65 years (36%) followed by those aged 17–30 (22%) years. UTI due to ESBL and Carbapenemase producer are more isolated in female (28%, 11%) as compare to male (16%, 6%). Indoor patients had higher prevalence of ESBL (29%) and carbapenemases (10%) isolation compare to OPD patient (ESBL-15%, Carbapenemases-7%) and among them most common ward was medicine department. The most common predisposing factor was catheterization followed by diabetes mellitus and obstructive uropathy. Discussion: High prevalence of ESBL and Carbapenemase producing Enterobacteriaceae is found in Indoor patients than OPD patients. Most of these patients are from Medicine department. Catheterization is the most common risk factor associated with ESBL and carbapenemase producing organism.

Worldwide Prevalence of Colistin Resistance among Enterobacteriaceae: a Systematic Review and Meta-Analysis.

The aim of the present meta-analysis is to estimate the prevalence of colistin resistance among the Enterobacteriaceae family. Articles from various databases (Medline, Scopus, Web of Science, and Embase) examining colistin resistance among Enterobacteriaceae in human, animal, and environmental specimens were searched from 2016 to 2021 using related keywords. The Cochran's Q-test and I2 were applied to evaluate heterogeneity and a random-effects model was used to assess the pooled prevalence. The meta-regression method was applied to determine heterogeneity among the studies. Of 5,145 articles, 60 articles with a sample size of 404,856 was included. The pooled estimate for prevalence of bacterial resistance were 9.13% (95% CI: 6.96 to 11.56; I-squared = 99.4%) in total, 8.34% (95% CI: 5.87 to 11.16; I-squared = 99.3%) for Klebsiella spp. subgroup and 3.44% (95% CI: 2.46 to 4.57; I-squared = 98.4%) for E. coli subgroup. The pooled prevalence for human and animal settings were 9.07% (95% CI: 6.77 to 11.67; I-squared = 99.3%) and 9.73% (95% CI: 484 to 16.02; I-squared = 99.4%), respectively. The continent (coefficient: 3.51; 95% CI: 0.08 to 6.94, p: 0.045) and bacterial type (coefficient: 0.03; 95% CI: 0.01 to 0.05 p: 0.042) had significant effects on heterogeneity among studies. The results of this study showed that the prevalence of colistin resistance in Enterobacteriaceae was similar between animals and humans, with the highest colistin resistance found in Klebsiella strains.

Reduced susceptibility to carbapenems in Enterobacteriaceae and antimicrobial resistance profile of Escherichia coli strains isolated from clinical and zoonotic sources in the Bamenda Municipality, Cameroon.

food-producing animals harbour pathogenic and antibiotic resistant bacteria which can be transmitted to humans. Resistance to carbapenems may complicate treatment resulting to debilitating consequences. This study aimed at determining the susceptibility of Enterobacteriaceae to carbapenems and to compare the resistant patterns of E. coli strains isolated from clinical and zoonotic sources. this was a cross-sectional study involving patients presenting at the Bamenda Regional Hospital and abattoir samples. Clinical samples (faeces and urine) and zoonotic samples (cattle faeces) were cultured and isolates identified using API-20E. Enterobacteriaceae isolates were tested for their susceptibility to Carbapenems. The susceptibility of E. coli was tested against eight antibiotics on Mueller Hinton agar. Data was analysed using SPSS version 20. Enterobacteriaceae isolates from clinical specimen showed susceptibility of 93.3% to carbapenems. Out of 208 isolates 14 (6.7%) were Carbapenem-resistant Enterobacteriaceae (CRE) while 30 (14.4%) showed intermediate resistance and 164 (78.9%) were susceptible. The predominant CRE were Proteus (7/16, 43.8%), Providencia (3/15, 20.0%) and E. coli (4/60, 6.7%) with E. coli being the most clinically significant CRE. Multiple drug resistance (MDR) was observed in 83% of E. coli isolates, with the highest resistance being against vancomycin (90, 81.8%), azithromycin (69, 62.7%) and doxycycline (68, 61.8%). Clinical isolates were significantly (P<0.05) more resistant to azithromycin, trimethoprim-suphamethoxazole and gentamicin than zoonotic isolates. CRE were detected among isolates and a high rate of multiple drug resistance was observed among E. coli isolates. Proper antibiotic policies and good hygiene/sanitation measures may curb the development/spread of CRE and MDR E. coli.

Screening for carriers of carbapenemase producing Enterobacteriaceae in critical care units

Background: The increasing cases of carbapenemase resistant Enterobacteriaceae (CRE) across the world is a cause of concern. Asymptomatic carriage of CRE in critical care units is a menace to infection control. Aims: This study determines the carriage rate of CRE in patients admitted to the intensive care units (ICU's) and evaluates the potential risk factors, leading to colonization in patients with CRE. Materials and Methods: Sixty rectal swabs from patients in the ICU's were screened for carriage of CRE. The samples were inoculated onto ChromID CARBA SMART bi-plate. The organisms showing color appearances as per the manufacturer's instructions were considered as CRE. Routine disk diffusion technique was also employed and CRE was defined as an organism belonging to the Enterobacteriaceae family which was resistant to either imipenem or meropenem. Results: The organisms isolated were identified and the percentage of carriage of carbapenem-resistant organisms was 12 (20%), of which Klebsiella pneumoniae was 4 (33.3%), Escherichia coli 6 (50%), Citrobacter freundii 1 (8.3%), and Enterobacter spp. 1 (8.3%). Out of these, 2 (3.3%) showed OXA 48 type resistance seen with K. pneumoniae and E. coli. Prior hospitalization, the use of high-end antibiotics and patients who have undergone surgeries were the most common potential risk factors for colonization with CRE. Conclusion: The prompt detection of CRE by routine screening using cost-effective methods and reduction of potential risk factors for gut colonization reduce the transmission of drug resistance in any hospital setting and pave the way for better antibiotic stewardship and appropriate contact isolation precautions.

Detection of β-lactamases among Multi-drug Resistant Enterobacteriaceae Colonising Gut of Normal Adults and Patient Population

Background and aims Antibiotic resistance is a growing threat in the medical field and the Enterobacteriaceae leading commensals in the gut are more likely to develop resistance. In this study we aimed to compare the anti-microbial resistance pattern with a special reference to beta-lactamase producers in Escherichia coli and Klebsiella pneumoniae as normal flora and pathogens.Methods A total of 120 bacterial strains of E. coli and Klebsiella were tested for antibiotic sensitivity by Kirby Bauer Disk diffusion method. Multi-drug resistant MDR bacteria were identified and phenotypically classified based on beta lactamase production into ESBL Extended Spectrum beta Lactamase AmpC beta Lactamase and MBL Metallo beta Lactamase respectively.Results Ampicillin resistance was the highest in both categories showing rates of 34 56 and 50 83.3 in normal and pathogenic strains respectively. Cefotaxime was a close second with resistance rates of 25 41.6 and 37 61.6. Imipenem showed the lowest resistance rates of 7 11.6 and 4 6.60 in normal and pathogenic strains. Pathogenic and normal strains showed an MDR rate of 51.6 and 40.5 respectively. ESBL production was observed in 1.6 P 41.6 N AmpC was 31.6 P 20 N and MBL was detected in 25 P 16.6 N.Conclusion The study revealed an alarming rate of beta lactamase-producing MDR commensals in the region. The narrow gap between the hospitalized and healthy individuals in resistance rates was a proof of rapid transmission of resistance genes signifying the need for screening even the normal population for antibiotic resistance patterns.

Evaluation of in-vitro colistin susceptibility and clinical profile of carbapenem resistant Enterobacteriaceae related invasive infections

PurposeTo determine the colistin susceptibility. To compare E-test vs broth-microdilution (BMD) method for invasive carbapenem resistant Enterobacteriaceae (CRE) infections. To study treatment options for the CRE. To analyze the clinical profile and outcome of CRE infections. MethodsAntimicrobial susceptibility testing was performed for 100 invasive CRE isolates. Gradient diffusion and BMD methods were performed to determine colistin MICs. Essential agreement (EA), categorical agreement (CA), very major error (VME), and major error (ME) were worked out between BMD method and E-test. The clinical profile of patients was analyzed. ResultsThe majority of the patients suffered from bacteremia [47(47%)]. Klebsiella pneumoniae was the most common organism isolated overall as well as among bacteremic isolates. 9(9%) CRE isolates were colistin resistant by BMD of which six were Klebsiella pneumoniae. There was 97% CA between E-test and BMD. EA was 68%. VME was found in three out of nine colistin resistant isolates. No ME was found. Among the other antibiotics tested for CRE isolates, the highest susceptibility was seen to tigecycline [43(43%)] followed by amikacin [19 (19%)]. The most common underlying condition was post solid organ transplantation [36(36%)]. A higher survival rate was seen among non-bacteremic CRE infections (58.49%) than bacteremic CRE infections (42.6%). Four out of nine patients with colistin resistant CRE infections survived and had a satisfactory outcome. ConclusionKlebsiella pneumoniae was the most common organism causing invasive infection. Survival rates were higher in non-bacteremic CRE infections than bacteremic infections. Good CA was seen between E-test and BMD for colistin susceptibility, but the EA was poor. VME was more common than ME when E-tests were used for colistin susceptibility testing resulting in false susceptibility. Tigecycline and aminoglycosides are possible adjunct drugs for the treatment of invasive CRE infections.

Multidrug-resistant VAP before and during the COVID-19 pandemic among hospitalized patients in a tertiary private hospital.

There is limited data on ventilator-associated pneumonia (VAP) and multidrug-resistant VAP (MDR VAP) among COVID-19 patients. A retrospective study in a single, tertiary, private hospital in the Philippines was conducted comparing the incidence, profile, and patient outcomes of MDR VAP during the pre-COVID-19 (2018-2019) and COVID-19 (2020-2021) periods. In total, 80/362 (22%) patients developed VAP, 27/204 (33.75%) from pre-COVID-19 and 53/158 (66.25%) from the COVID-19 period, respectively. The majority were male [20/27 (74%) vs 34/53 (64%)], with a median age of 66 (range 35-90) and 67 (range 32-92) years in each period, respectively. Comorbidities were similar, except cardiovascular disease (14/27 vs 11/53 patients, p-value 0.005) and chronic lung disease (14/27 vs 9/53 patients, p-value 0.0012). VAP incidence density was 19.3/1000 and 27.8/1000 ventilator days (p-value 0.9819)]; median length of stay before VAP for pre- and COVID-19 periods was 17 and 10 days, respectively (p-value <0.0001). Extended-spectrum β lactamase (ESBL)-producing resistance increased significantly [1/27 (3.7%) pre-COVID-19 vs 15/53 (28.3%)]during COVID-19, while Carbapenem-resistant Enterobacteriaceae resistance was higher in the pre-COVID-19 period(15/27 [56%] vs 10/53 [19%]). Mortality was high in both periods at 93% and 83%, respectively. On multivariate analysis, only female gender was associated with MDR VAP in the COVID-19 period (OR =3.47, [CI 1.019, 11.824], p-value < 0.047). The frequency of VAP and MDR VAP increased during the COVID-19 period, despite a shorter duration of hospital stay. The mortality of VAP was extremely high. Factors associated with increased risk of VAP and COVID-19 need to be studied further, and preventive measures should be prioritized.

Horizontal Transfer of Plasmid Mediated Carbapenem Resistant Genes from Klebsiella pneumoniae to Escherichia coli

Carbapenem resistance among Enterobacteriaceae is an emerging problem worldwide. Klebsiella pneumonia carbapenemase (blaKPC) enzymes are amongst the most common beta-lactamases that have been studied. This broad group of organisms with various resistance mechanisms is associated with increased lengths of hospitalization, costs of medical care, morbidity, and mortality. The global spread of Carbapenem Resistance Enterobacteriaceae (CRE) has largely been attributed to disseminating a dominant strain of Klebsiella pneumoniae producing a serine beta-lactamase, termed as Klebsiella pneumonia carbapenemase (KPC). This study was designed to determine in vitro efficacy of horizontal transfer of plasmid-mediated carbapenem-resistant genes from Klebsiella pneumoniae to Escherichia coli. A total of 30 gram-negative rods from different clinical samples were taken. After preliminary antimicrobial susceptibility screening, isolates that showed a resistance zone were included in the study. These isolates were then subjected to the Modified Hodge test for confirmation of carbapenemase production. Out of 10 isolates, four were positive for carbapenemase production. The plasmid from these resistant strains was transformed into DH5α. RFLP analysis was carried to evaluate these transgenic cells resulted in horizontal gene transfer of resistant plasmid DNA from Klebsiella pneumoniae to Escherichia coli.

ANTIBIOTIC SUSCEPTIBILITY PATTERN OF CARBAPENEM RESISTANT ENTEROBACTERIACEAE AMONG UROPATHOGENS ISOLATED IN A REFERRAL LABORATORY OF KARACHI

Objective: To determine the antibiotic susceptibility pattern of Carbapenem resistant Enterobacteriaceae among uropathogens isolated in a referral laboratory in Karachi. Methodology: It is a retrospective cross-sectional study, carried out at the Department of Microbiology of Dow Diagnostic Research and Reference Laboratory. All urine samples collected during the study period of 6 months from October 2020 to March 2021 were tested for culture and sensitivity patterns by the disc diffusion method. Data of urine culture and sensitivity test reports were taken from the medical record. and analyzed by using SPSS version 16. Results: Out of the total 10925 uropathogens isolated, 67% belonged to Enterobacteriaceae family. The most frequent isolate among them was Escherichia coli 84% followed by Klebsiella species at 10%. The overall frequency of Carbapenem resistance was 6%. The frequency of Carbapenem resistance was higher in Klebsiella species 27% than Escherichia coli 8%. Multi-drug resistance was observed in both Escherichia coli and Klebsiella species especially against Ampicillin, followed by Cefixime, Cefuroxime, Ceftriaxone, Cotrimoxazole and Ciprofloxacin. Conclusion: The study showed a significant rate of Carbapenem resistance among Enterobacteriaceae which emphasizes the need for formulating an antimicrobial policy with its strict implementation and regular surveillance to control the spread of Carbapenem resistant Enterobacteriaceae at the hospital and community level.

Distribution of Extremely Heat-Resistant Escherichia coli in the Beef Production and Processing Continuum

Understanding the dynamics of stress-resistant Escherichia coli (E. coli) across the meat production and processing continuum is important for tracking sources of such microbes and devising effective modes of control. The Locus of Heat Resistance (LHR) is a ∼14–19 Kb genetic element imparting extreme heat resistance (XHR) in Enterobacteriaceae. It has been hypothesized that thermal and antimicrobial interventions applied during meat processing may select for LHR+E. coli. Thus, our goal was to study the prevalence and molecular biology of LHR+E. coli among lots of beef cattle (n = 3) from production through processing. Two hundred thirty-two generic E. coli isolated from the same animals through seven stages of the beef processing continuum (cattle in feedyards to packaged strip loins) were examined. LHR+E. coli were rare (0.6%; 1 of 180) among the early stages of the beef continuum (feces and hides at feedlot, feces and hides at harvest, and preevisceration carcasses), whereas the prevalence of LHR+E. coli on final carcasses and strip loins was remarkably higher. Half (14 of 28) of the final carcass E. coli possessed the LHR, while 79.2% (19 of 24) of the strip loin E. coli did. Eighty-five percent (29 of 34) of the LHR+E. coli presented with the XHR phenotype. The selection or enrichment of LHR+E. coli from harvest steps to the final products appeared unlikely as the LHR+E. coli isolates were effectively controlled by antimicrobial interventions typically used during beef processing. Further, whole-genome sequencing of the isolates suggested LHR+E. coli are persisting in the chilled processing environment and that horizontal LHR transfer among E. coli isolates may take place.

Long-term adaptation of ParA, RelE/ParE partition system, replication protein and phage proteins encoding low-cost plasmids ofEscherichiaspecies isolated from diarrheic children of North East India

The prevalent distribution of plasmid-mediated β-lactam resistance is the most pressing global problem in enteric diseases. The current work aims to characterize plasmid-carrying β-lactam resistant Enterobacteriaceae isolates from North East India for horizontal gene transfer (HGT) and plasmid adaptation study. In vitro transconjugation and transformation showed overall high conjugation frequency (4.11×10-1-9.2×10-1) and moderate transformation efficiency/µg DNA (1.02×102 -1×103), and the highest conjugation frequency (9.2×10-1) and transformation efficiency (1×103) for Escherichia species S-10. Intra/intergenus plasmid transformation efficiency was highest for the transformation of Klebsiella pneumoniae S-2 to Shigellaflexneri S-42 (1.3×103) and lowest for Escherichia species S-10 to Escherichia fergusonii S-30 (2×102). In the plasmid stability test, S-10 was detected with the highest plasmid carrying frequency (83.44%) and insignificant segregational loss rate (0.0004) until the 60th day with low plasmid cost on the host. The above findings were also validated by whole-plasmid sequencing of Escherichia species S-10. The genome was identified with two plasmids constituting multiple phage proteins, relaxosomal protein NikA, replication protein RepA, and the plasmid maintenance proteins (ParA, RelE/ParE), thus assisting stable plasmid maintenance. The results thus indicate that the high conjugation ability and low plasmid fitness cost might lead to horizontal gene transfer of the plasmid to the environment due to their prolonged adaptation in nonselective conditions, intensifying the infection's severity.

669. Real World Use of Ceftazidime/Avibactam for the Treatment of Multidrug Resistant Gram Negative Bacilli Infections: A Real World Experience from Two Centers in Mexico

Abstract Background Ceftazidime-avibactam (C-A) is effective against many carbapenem resistant Enterobacteriaceae (CRE) and some carbapenem resistant Pseudomonas aeruginosa (CRPsa), indicated in complicated urinary tract infections (cUTI), complicated intra-abdominal infections (cIAI), and hospital-acquired pneumonia. To our knowledge, in Mexico, there is no data regarding the clinical efficacy (clinical cure) of its use in the treatment of cIAI, cUTI, hospital-acquired pneumonia, and the treatment of CRE and CRPsa. Methods this is a descriptive, observational, retrospective study, including infections in which ceftazidime avibactam was the definitive therapy for CRE and CRPsa, and empiric treatment of cUTI, cIAI, Hospital-acquired pneumonia. The study includes patients from 2 centers, between April 2019 and february 2020. Demographic, clinical and microbiological data were obtained. Clinical cure was defined as the absence of fever, leukocytosis, tachycardia, systolic pressure &amp;lt; 90mmHg or use of vasopressors, and lowering of C-reactive protein by at least 60% after 5 days of treatment. Results Seventy patients in which C-A was the definitive antimicrobial treatment were evaluated. UTI accounts for 24 cases (34.2%), followed by primary and secondary peritonitis (28.5%), soft tissue infection (12.8%), bacteremia (12.8%) and hospital-acquired pneumonia (11.4%). Of all infections 39.9% were secondary to CRPsa, and 60.1% were due to CRE (30.3% Klebsiella pneumoniae, 21.2% Escherichia coli and 6% for Klebsiella oxytoca, Enterobacter cloacae and Proteus mirabilis). Clinical cure was achieved in 64 patients (91.4%). Six patients died, but only one was associated to CRPsa infection. Conclusion To the best of our knowledge, this is the first study of Mexican experience with C-A. Our study brings relevant information on the treatment of carbapenem resistant GNB infections with C-A in our population. More studies, specifically RCTs are needed to prove the antibiotic efficacy in our media. Disclosures All Authors: No reported disclosures.

2111. Impact of Colonization by Multi Drug Resistant Bacteria on Graft Survival, Risk of Infection, and Mortality in Recipients of Solid Organ Transplant: Systematic Review and Meta-analysis

Abstract Background Colonization with multi-drug resistant bacteria (MDR) in solid organ transplant (SOT) recipients increases the risk of post-transplant bacterial infection. MDR colonization impact on graft survival and mortality is not well established. Methods A search was executed by an expert librarian on PROSPERO, OVID Medline, Ovid EMBASE, Wiley Cochrane Library, ProQuest dissertations and Theses Global and SCOPUS, from inception until October 26, 2021. Adult SOT colonized with Methicillin resistant Staphylococcus aureus (MRSA), Vancomycin-resistant Enterococci (VRE), Extended-spectrum beta-lactamase (ESBL) or AmpC producing bacteria, carbapenem resistant Enterobacteriaceae (CRE), or MDR Pseudomonas were included and compared to non-colonized SOT. Pairs of reviewers screened abstracts and full studies for inclusion, and extracted data independently. We used RevMan to conduct a meta-analysis using random effects models to calculate the pooled risk ratio (RR) with 95% confidence interval (CI) for the incidence of infection, mortality, and graft failure. Statistical heterogeneity was determined using the I2 statistic. Figure-1 PRISMA chart, systemic review and metanalysis on Impact Of Colonization By Multi Drug Resistant Bacteria on Graft Survival, Risk of Infection, and Mortality in Recipients of Solid Organ Transplant. Results 59 articles spanning from 1989 to 2021 were included (Figure-1). Liver transplant (43 studies) and VRE colonization (17 studies) were the most common organ and MDR pathogen. MDR surveillance was performed by culture (71%) and PCR (6.7%). In liver transplant recipients, VRE and MRSA colonization were associated with increased infection risk, but not mortality (VRE infection: RR= 2.40 (95%CI 1.54-3.73; p&amp;lt; 0.001), I2= 66%; VRE mortality: RR= 1.64 (95%CI 0.88-3.05; p=0.12), I2= 44%; MRSA infection: RR= 4.07 (95%CI 2.66-6.24; p&amp;lt; 0.001), I2= 59%; MRSA mortality RR=1.47 (95%CI 0.79-2.76; p=0.23), I2= 35%). ESBL and CRE colonization were associated with increased risk of infection (ESBL: RR=9.87 (6.12-15.93); p&amp;lt; 0.001), I2=13%; CRE: RR= 13.64 (95%CI 5.73-32.47); p&amp;lt; 0.001), I2= 66%). CRE colonization was associated with increased mortality, RR=5.79 (95% CI 1.80-18.63; p=0.003), I2=0%. Conclusion While colonization with MRSA and VRE in liver transplant was not associated with increase mortality, CRE colonization was associated with almost 6-fold increased risk of death. These data should be taken into account when stratifying the risk of transplant. Disclosures Carlos Cervera, Associate Professor, Astra-Zeneca: Advisor/Consultant|AVIR Pharma: Grant/Research Support|AVIR Pharma: Honoraria|Lilly: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Merck: Honoraria|Sunovion: Advisor/Consultant|Takeda: Advisor/Consultant|Takeda: Honoraria|VerityPharma: Advisor/Consultant Dima Kabbani, MD, MSc, AVIR Pharma: Grant/Research Support|AVIR Pharma: Honoraria|GSK: Honoraria|Merck: Grant/Research Support.