Occurrence of K1 and K2 serotypes and genotypic characteristics of extended spectrumβ-lactamases-producing Klebsiella pneumoniae isolated from selected hospitals in Malaysia

Objective:To determine the distribution,phenotypic and genetic background of extended spectrumβ-lactamases(ESBL)-producing Klebsiella(K.)pneumoniae clinical isolates associated with K1 and K2 serotypes in two selected hospitals in Malaysia.Methods:A total of 192 K.pneumoniae isolates were collected and subjected to antibiotic susceptibility,hypermucoviscosity test and multiplex PCR to detect the presence of K1-and K2-serotype associated genes.Multilocus sequence typing(MLST)was performed on ESBL-producing K.pneumoniae isolates presented with K1 and K2 serotypes,followed by phylogenetic analysis.Results:A total of 87 out of 192(45.3%)of the K.pneumoniae isolates collected were ESBL producers.However,only 8.3%(16/192)and 10.9%(21/192)of the total isolates were detected to carry K1-and K2-serotype associated genes,respectively.Statistical analysis showed that K1 and K2 capsular serotypes were not significantly associated with ESBL phenotype(P=0.196).However,they were significantly associated with hypervirulent,as demonstrated by the positive string test(P<0.001).MLST analysis revealed that ST23 as the predominant sequence type(ST)in the K1 serotype,while the ST in the K2 serotype is more diverse.Conclusions:Although the occurrence of ESBL-producing isolates among the hypervirulent strains was low,their coexistence warrants the need for continuous surveillance.MLST showed that these isolates were genetically heterogeneous.

Evaluation of Disk Potentiation Test (DPT) and Double Disk Synergy Test (DDST) for The Detection of Metallo-β-Lactamases (MBLs) in Clinical Isolates of Bangladesh

Objective: Increasing the emergence of Metallo-β-lactamase (MBL) producing gram-negative bacteria and their dexterous horizontal transmission demands rapid and accurate detection. This study was conducted to determine a suitable method to promptly detect MBL-producing gram-negative bacteria. Methods: A total of 103 gram-negative bacteria were identified from various clinical samples at a tertiary care hospital in Dhaka city. MBL producers were detected by two phenotypic methods, the Disk Potentiation Test (DPT) and the Double Disk Synergy Test (DDST) based on β-lactam chelator combinations where EDTA/SMA has been used as an inhibitor and Imipenem, Ceftazidime as substrates. Results: 103 isolates which were identified as Escherichia coli spp, Klebsiella spp, Pseudomonas spp, Acinetobacter spp, Proteus spp, Providencia spp were found to be multidrug-resistant in antibiogram test. Isolates showed complete resistance (100%) to Imipenem, Meropenem, and Amoxiclav. The highest carbapenem-resistant etiological agents were Acinetobacter spp 40 (38.8%) followed by Pseudomonas spp 27 (26.2%), Klebsiella spp 26 (25.2%), Escherichia coli 8 (7.8%), Proteus spp 1 (1%) and Providencia spp 1 (1%). DPT method detected significantly (p = 0.000009) a higher number of MBL-producers (Imipenem with 0.5 M EDTA n = 61, 59.2% & Ceftazidime with 0.5 M EDTA n = 56, 54.4%) compared to the DDST method (Imipenem -0.5 M EDTA n = 43, 41.7%, Imipenem – SMA n = 38, 36.9% & Ceftazidime -0.5 M EDTA n = 15, 14.6%). Conclusion: Pieces of evidence suggest that DPT is a more sensitive method than DDST and could be recommended for identifying MBL-producing bacteria in Bangladeshi hospitals for the proper management of patients, to reduce time constraints and treatment costs.

Characteristics of β-Lactamase Synthesis in E. coli and K. pneumanie Strains in Nosocomial Infections

Background: Recently micro-organisms that synthesize extended-spectrum β-lactamase (ESBLs) were increased. The peculiarities of ESBL synthesis of Escherichia coli and Klebsiella pneumoniae strains that cause nosocomial urinary tract infections, surgical site infections and pneumonia in surgical clinic were studied. ESBL synthesis were observed 38.9% of E. coli strains obtained from urine, 92.3% of strains obtained from surgical site infections, and 50% of strains obtained from sputum. ESBL synthesis were observed 37.5% of K. pneumoniae strains obtained from urine, 85.7% of strains obtained from surgical site infections, and 60% of strains obtained from sputum. Different levels of ESBL synthesize of E. coli and K. pneumoniae strains isolated from different pattern is discussed. Conclusion. ESBL synthesis is common in E. coli and K. pneumoniae strains, which cause nosocomial infections. The frequency of occurrence of ESBL s synthesis among of these strains depends on clinical forms of nosocomial infections.

Metallo-β-Lactamases:A Major Threat to Human Health

Antibiotic resistance is one of the most significant challenges facing global healthcare. Since the 1940s, antibiotics have been used to fight infections, initially with penicillin and subsequently with various derivatives including cephalosporins, carbapenams and monobactams. A common characteristic of these antibiotics is the four-memberedβ-lactam ring. Alarmingly, in recent years an increasing number of bacteria have become resistant to these antibiotics. A major strategy employed by these pathogens is to use Zn(II)-dependent enzymes, the metallo-β-lactamases (MBLs), which hydrolyse theβ-lactam ring. Clinically useful MBL inhibitors are not yet available. Consequently, MBLs remain a major threat to human health. In this review biochemical properties of MBLs are discussed, focusing in particular on the interactions between the enzymes and the functionally essential metal ions. The precise role(s) of these metal ions is still debated and may differ between different MBLs. However, since they are required for catalysis, their binding site may present an alternative target for inhibitor design.

Microbiologic and Clinical Comparison of Patients Harboring <i>Escherichia coli</i>Blood Isolates with and without Extended-Spectrum <i>β</i>-Lactamases

The clinical and microbiologic characteristics of 34 patients with extended-spectrum β-lactamase (ESBL) positive E. coli isolated from blood were compared to 66 bacteremic patients with ESBL negative E. coli, from January 2007 through December 2009. Of the 21 ESBL positive isolates available for PCR analysis, 13 were positive for CTX-M, 8 for TEM, 4 for SHV β-lactamases, with 6 possessing multiple enzymes. Twenty of 34 (59%) ESBL-positive and 41 of 66 (62%) ESBL-negative blood isolates were considered community-associated. All but one isolate in both groups had MICs of ≤1.0 μg/ml to meropenem. However, when compared to ESBL-negative isolates, ESBL-positive isolates were more frequently resistant to levofloxacin, trimethoprim/sulfamethoxazole and had higher MICs to gentamicin, tobramycin and piperacillin/tazobactam. The use of intravenous and urinary catheters was strongly associated with the isolation of E. coli bloodstream isolates in both groups of patients. Although hospital stay was similar in both groups, appropriate therapy was given in 87% of patients with ESBL positive vs. 98% of patients with ESBL negative isolates and mortality was greater for patients with ESBL positive isolates (26% vs. 17%). Since a large proportion of E. coli blood isolates were ESBL-positive and community-associated, carbapenems should be considered as initial empiric therapy for such infections in our locale.

Computational Calculations of Molecular Properties and Molecular Docking of New and Reference Cephalosporins on Penicillin Binding Proteins and Various β-Lactamases

An approach of using molinspiration calculations and molecular docking on PBPs （penicillin-binding proteins） and certain β-lactamases is employed to predict the molecular properties, bioactivity and resistance of newer and reference cephalosporins. The previously synthesized cephalosporins 1-8 and reference cephalosporins were subjected to extensive evaluations by calculating the molecular properties, drug-likeness scores on the bases of Lipinski＇s rule and bioactivity prediction using the method of molinspiration web-based software. The TPSA （topological polar surface area）, OH-NH interactions, n-violation and the molinspiration Log partition coefficient （miLogP） values were also calculated. The investigated cephalosporins were subjected to molecular docking study on PBPs （lpyy） and on β-lactamases produced by S. aureus, K. pneumonia, E. coil and P. auroginosa using 1-click-docking website. Molecular properties of 1-8 recorded higher ＂FPSA than cephalexin and were lower than the reference cephalosporins and do not fulfill the requirements for Lipinski＇s rule. Bioactivities of 1-8 were predicted to be less and their docking scores on PBPs were comparable to those of the reference cephalosporins, particularly ceftobiprole. The references recorded various docking scores on the above β-lactamases and as expected, cefiobiprole recorded the lowest scores on all β-lactarnases. Cephalosporins 1-8 recorded various docking scores on β-lactamases. Molecular docking studies on PBPs and β-lactamases are considered as very useful, reliable and practical approach for predicting the bioactivity scores and to afford some information about the stability and selectivity of the newly proposed cephalosporins against β-lactamases of certain pathogenic microbes, such as P. auroginosa and MRSA, by recording the relative docking scores in comparison with those of reference cephalosporins.

Unusual metallo-β-lactamases may constitute a new subgroup in this family of enzymes

Metallo-β-lactamases (MBLs) are a family of Zn2+-dependent enzymes that have contributed strongly to the emergence and spread of antibiotic resistance. Novel members as well as variants of existing members of this family are discovered continuously, compounding their threat to global health care. MBLs are divided into three subgroups, i.e. B1, B2 and B3. The recent discovery of an unusual MBL from Serratia proteamaculans (SPR-1) suggests the presence of an additional subgroup, i.e. B4. A database search reveals that SPR-1 has only one homologue from Cronobacter sakazakii, CSA-1.These two MBLs have a unique active site and may employ a mechanism distinct from other MBLs, but reminiscent of some organophosphate-degrading hydrolases.

Identification and preliminary characterization of novel B3-type metallo-β-lactamases

Antibiotic resistance has emerged as a major global threat to human health. Among the strategies employed by pathogens to acquire resistance the use of metallo-β-lactamases (MBLs), a family of dinuclear metalloenzymes, is among the most potent. MBLs are subdivided into three groups (i.e. B1, B2 and B3) with most of the virulence factors belonging to the B1 group. The recent discovery of AIM-1, a B3-type MBL, however, has illustrated the potential health threat of this group of MBLs. Here, we employed a bioinformatics approach to identify and characterize novel B3-type MBLs from Novosphingobium pentaromativorans and Simiduia agarivorans. These enzymes may not yet pose a direct risk to human health, but their structures and function may provide important insight into the design and synthesis of a still elusive universal MBL inhibitor.

Prevalence and Risk Factors of Penicillinase-Type β-Lactamase Producing Neisseria gonorrhoeae Isolated from Patients Attending Health-Facilities in Yaounde, Cameroon

Background and Objectives: Mitigation of antibiotic resistant Neisseria gonorrhoeae has become a priority due to considerable health and economical disabilities it generates. In order to tackle the emergence of resistant Neisseria gonorrhoeae, this study aimed to determine the prevalence and risk factors of penicillinase type β-lactamase-producing Neisseria gonorrheae among patients consulting for genital infectious disorders in two health-facilities in Yaounde, Cameroon. Materials and Method: A cross-sectional descriptive and analytical study was conducted over a 3-month period, from July 2nd to October 2nd, 2022. Vaginal and urethral secretions were collected. Biochemical identification tests were performed on colonies grown on chocolate agar + polyvitex using the Api NH gallery. The detection of penicillinases was equally performed using the API NH gallery and confirmed using the antimicrobial susceptibility testing. The Minimum Inhibitory Concentrations of some antibiotics were determined using the E-Test. Results: The results showed that out of the 198 patients sampled, 16 (8.08%) were positive for Neisseria gonorrhoeae, among which 13/16 (81.25%) were penicillinase-type β-lactamase producers. Antimicrobial susceptibility testing results showed high co-resistances to antibiotics, mainly ciprofloxacin (100%), nalidixic acid (92.31%) and azithromycin (84.62%). Moreover, high Minimum Inhibitory Concentrations of ceftriaxone (ranging from 6 to 24 mg/L) was observed toward Neisseria gonorrhoeae isolates. The risk factors of the carriage of penicillinase-type β-lactamase producing Neisseria gonorrhoeae identified were: a history of Sexually Transmitted infections (p = 0.01) and unprotected sexual intercourse (p = 0.01). Conclusion: The emergence of penicillinase-type β-lactamase producing Neisseria gonorrhoeae is increasing and the situation is becoming worrisome. The identified risk factors can constitute a basic outlook to tackle resistant Neisseria gonorrhoeae, and therefore sustain antibiotic stewardship.

Dissemination of carbapenem-non-susceptible Acinetobacter baumannii isolates collected from educational hospitals in Qazvin province of Iran

Background:Acinetobacter baumannii(A.baumannii)is known as an opportunistic pathogen related to health-care-associated infection that has a high antibiotic resistance potential,notably against carbapenems that are widely used to combat A.baumannii infections.This study aimed to detect oxacillin-hydrolyzing(OXA)carbapenemases and metallo-β-lactamases(MBL)among carbapenem-resistant A.baumannii isolated strains and to determine their clonal relationship by repetitive extragenic palindromic PCR(rep-PCR).Methods:In the present study,a total of 211 non-repetitive isolates of A.baumannii were collected from Qazvin educational hospitals(2016–2017).The disk diffusion method was used to investigate the antibiotic susceptibility of studied strains,followed by the detection of MBL and OXA-type genes using polymerase chain reaction(PCR)and sequencing methods.The rep-PCR method assessed the clonal relationship of carbapenem-non-susceptible A.baumannii isolates.Result:The obtained results showed that 87.2%and 86.7%of isolates were non-susceptible to imipenem and meropenem.The blaOXA-24(93.5%)was the most frequent gene,followed by the blaOXA-23(4.34%),blaIMP-1(1.63%),and blaVIM-1(0.54%).Meanwhile,blaOXA-58 and blaOXA-143 genes were not found.81.5%and 66.1%of isolates contained ISAba1 upstream of the blaOXA-23 and blaOXA-58 genes,respectively.Rep-PCR results revealed the carbapenem non-susceptible isolates belonged to three distinct clones:A 171(81%),B 34(16.1%),and C 6(2.8%).Conclusions:The results indicated a high prevalence of carbapenem-non-susceptible A.baumannii,with the emergence of the blaOXA-24 gene as the most common gene and the notable prevalence of MBL genes.These results revealed the need for appropriate therapeutic and infection control strategies and monitoring susceptibility patterns for controlling A.baumannii infections.

L1 β-Lactamase催化反应机理研究

用混合量子力学和分子力学(QM/MM)方法和密度泛函理论讨论了L1β-Lactamase催化Nitrocefin水解的过程,研究结果表明,反应为多步反应:第一步亲核进攻反应为反应的决速步骤,并且伴随着酰胺键的断裂,第二步反应为质子迁移反应.同时讨论了金属锌在反应中的作用.

Prevalence and characteristics of extended spectrum β-lactamase-producing Escherichia coli from bovine mastitis cases in China

The aim of the study was to investigate the prevalence and characterization of extended-spectrum β-lactamase （ESBL）- producing Escherichia coli isolated from bovine mastitis cases in China. ChromID ESBL agar was used to confirm ESBL-producing E. coli. PCR and DNA sequencing were employed to characterize the genotype of ESBL-producers. Antimicrobial susceptibility was measured by disc diffusion. Overall, 73 of 318 E. coli isolates （22.96％） were identified as ESBL-producers. Of these ESBL-producing E. coli, the prevalence of blaCTX-M and blaTEM-1 was 97.26 and 71.23％, respectively. The predominant CTX-M-type ESBL was CTX-M-15 （65.75％）, followed by CTX-M-14 （10.96％）, CTX-M-55 （9.59％）, CTX-M-64 （5.48％）, CTX-M-65 （4.11％） and CTX-M-3 （1.37％）. This study is the first report of CTX-M-64 and CTX-M-65 in E. coli isolated from bovine mastitis. Furthermore, 72 ESBL-producing E. coli isolates （98.63％） were found to be multidrug-resistance. This study noted high prevalence and rates of antimicrobial resistance of ESBL-producing E. coli isolates from bovine mastitis cases in China.

Analysis of AmpC β-lactamase Gene in Pseudomonas aeruginosa

The gene and the amino acid sequence of the structural and regulatory region of the Pseudomonas aeruginosa with different resistance patterns were analyzed. Six strains with different resistance patterns were selected and the AmpC β-lactamase was identified. The objective gene fragment was amplified by colonies PCR. The sequences of the PCR-products were analyzed. The DNA sequence of the structural gene ampC and the regulatory genes ampR, ampD and ampE was detected. The 6 strains and the wild-type Pseudomonas aeruginosa are highly homogeneous in structural and regulatory region. Some new mutant points were found.

Antimicrobial Resistance and Genotype Analysis of Extended-Spectrum-β-Lactamase-Producing Proteus Mirabilis

To analyse the genotypes of clinical isolates of Extended-Spectrum-β-Lactamase-Producing (ESBL-producing) Proteus mirabilis (P. mirabilis) and the mechanisms of antimicrobial resistance, to guide reasonable use of antibiotics and to avoid nosocomial outbreak infections by ESBL-producing P. mirabilis. 125 clinical isolates of P. mirabilis were collected from the Drug-Resistant Bacteria Surveillance Center of Anhui Province (from Jan 2009 to May 2010). Searching for the genotypes of ESBLs was perfomed by PCR amplification and DNA sequencing, and performed conjugation test simultaneously. Among ESBL-producing strains, CTX-M was the major genotype (3 CTX-M-13 and 1 CTX-M-3). TEM-1b spectrum β-lactamase was also prevalence in P. mirabilis. The diversity of β-lactamases in P. mirabilis and the emergency of multi-drug-resistance clinical strains will present serious threat to clinical therapy and even will lead to outbreak of nosocomial infections. Our study emphasizes the need for enhanced supervision of ESBL-producing P. mirabilis. Timely and reasonable drug-resistance data are indispensable to clinical therapy.

EXTRACELLULAR RELEASE OF β-LACTAMASE BY OSMOTIC SHOCK IN SYNECHOCOCCUS TRANSFORMANT

A unicellular cyanobacterium Synechococcus sp. strain PCC 7002 was transformedwith plasmid pQL1, on which β-lactamase gene (bla) and β-galactosidase gene (lacZ) were encoded.The transformant cells released β-lactamase into medium by an abrupt drop of osmotic pressure. This re-sult indicates that this cyanobacterium recognizes and processes the signal sequence of β-lactamase, andaccumulates the enzyme in periplasm. Repeated release of β-lactamase was possible by repeated osmoticshocks without impairing cell viability. On the other hand, most of the β-galactosidase remained in cyto-plasm under the osmotic shock.

Metallo-β-lactamase producing nonfermentative gram-negative bacteria:An increasing clinical threat among hospitalized patients

Objective:To detect and evaluate the various methods for metallo-β-lactamases(MBL) production in Pseudomonas aeruginosa(P.aeruginosa) and Acinetobacter species.Methods:A total of 109 P.aeruginosa and 85 Acinetobacter species were screened for imipenem resistance by Kirby- Bauer disc diffusion methods.Detection of MBL production was(lone by imipenem-EDTA combined disc test,double disc synerygy test(DDST) and imipenem-EDTA MBL E test.Results: A total of 63(57.8%) strains of P.aeruginosa and 46(54.1%) strains of Acinetobacter spp.were found to be resistant to imipenem.Of the 63 imipenem resistant P.aeruginosa tested for MBL production.44(69.89;) were found to be positive and among 46 imipenem resistant Acinetobacter. 19(41.3%) were shown to be the MBL producers.Conclusions:Imipenem-EDTA combined disc test and MBL E test are equally effective for MBL detection in both P.aeruginosa and Acinetobacter spp.,but given the cost-constraints,combined disc can be used as a convenient screening method in the clinical microbiology laboratory.

Multidrug resistance extended spectrum β-lactamase and AmpC producing Escherichia coli isolated from the environment of Bogor Slaughterhouse,Indonesia

To determine the multidrug resistance extended spectrum β-lactamase and AmpC (ESBL/AmpC producing) Escherichia coli (E. coli) isolated from the environment of Bogor slaughterhouse, Indonesia.MethodsA total of 35 samples from 7 locations in slaughterhouse i.e., source of water, slaughtering floor, swab of carcass area floor, swab of evisceration area floor, untreated waste water, treated waste water, drinking water for cattle were collected from March to April 2016. Presence of ESBL/AmpC producing E. coli and susceptibility testing against 8 antimicrobial agents (penicillin G, streptomycin, gentamycin, ciprofloxacin, enrofloxacin, tetracycline, trimethoprim-sulfamethoxazole, and polymyxin B) were detected by disk diffusion test according to Clinical and Laboratory Standards Institute.ResultsESBL/AmpC producing E. coli were identified in 14.3% (5/35) of the collected samples from the environment of Bogor slaughterhouse. ESBL/AmpC-producing E. coli isolates were detected in untreated waste water (n = 3), slaughtering floor (n = 1), and carcass area floor (n = 1). Most of ESBL/AmpC-producing E. coli isolates (80%) showed multidrug resistance phenotypes against at least three classes of antibiotics. The highest incidence of antibiotics resistance was against penicillin G (100.0%) and streptomycin (100.0%), followed by gentamicin (60.0%), trimethoprim-sulfamethoxazole (60.0%), tetracycline (40.0%), ciprofloxacin (40.0%), enrofloxacin (20.0%), and polymyxin B (0.0%).ConclusionsThe transmission of antimicrobial resistant bacteria into the environment may be a potential risk for human health.

Studies of β-lactamase production in ampicillin resistant Haemophilus influenzae

Objective:To study the molecular mechanisms of β-lactamase production in ampicillin resistant(AmP ) Hae- mophilus influenzae(HI). Methods: Identified the β-lactamases production strain from AmP HI was isolated from clinical cases with K-B method. β-lactamase encoding gene in enzyme production strains were detected by PCR with lactamase gene specific primers, and both plasmid and chromosomal DNA samples. Results: Thirty-two out of 36 (88 .9% ) were found to be β-lactamase production. Twenty-nine out of 32 enzyme production stain were PCR positive (the ratio of PCR positives 90.6% ). There were 25 stains amplified with plasmid DNA positively, and 4 with chromosomal DNA. Conclusion: (l ) Most of the AmPr HI strain produce lactamase is mediated by plasmid. (2) Detection of lactamase encoding gene in HI is a simple and efficient approach to study the molecular basis of ampicillin resistance.

Intestinal carriage of methicillin resistant Staphylococcus aureus and extended-spectrum β-Lactamase-producing Enterobacteriacae in hospitalized and nonhospitalized patients and their clinical implications

Objective:To determine the clinical implication of and intestinal carriage with methicillin resistant Staphylococcus aureus(MRSA) and extended spectrumβ-lactamase(ESBL)-producing Enterobacteriacae.Methods: A total of 180 stool specimens were screened for MRSA and ESBL-producing enterobacteria.Identification of ESBL- producing Enterobacteriacae was done by MicroScan Walk Away 96 system(Dade Behring Inc.,West Sacramento,CA 95691,USA ) and confirmation by double-disc synergy test.MRSA was identified by disc diffusion using 30μg cefoxitin disc and the MicroScan.Results:The rate of fecal MRSA carriage was 7.8% (14/180),35.7%(5 /14) were recovered from surgical wards.Three patients(21,4%) had MRSA recovered from other body sites,and 2(14.2%) had in addition ESBL -producing Escherichia coli(E.coli) and Klebsiella pneumoniae(K.pneumoniae) respectively.Four(28.5%) patients with MRSA fical carriage died. MRSA fecal carriage was recovered from both inpatients and outpatients.Four(2.2%) cases carried ESBL-producing Enterobacteriacae in feces.Three(75%) were from intensive care unit(ICU).One patient had both ESBL-producing E.coli and K.pneumoniae from stool as well as E.coli from tracheal aspirate.Two ICU patients with fecal ESBL died.Conclusion:Fecal screening for MRSA and ESBL of all patients at high risk admitted to different hospital wards and ICUs and implementing infection control measures were recommended.

Prevalence and Potential Risk Factors of Hospital Acquired Extended-Spectrum Beta-Lactamase—Producing <i>Proteus</i>Species

Background: Multidrug resistance and production of extended spectrum β-lactamases (ESBLs) by a large group of bacterial agents in hospitals are to be a matter of scientific concern. Objective: This cross-sectional study was aimed to investigate the prevalence of ESBL producing Proteus species and risk factors associated with hospital acquired infection in addition to study the antibiotics susceptibility patterns of all bacterial isolates from inpatients of four Yemeni general hospitals. Methods: A total of 740 consecutive non-repeat culture isolates were obtained from admitted patients of Al-Kuwait University Hospital, Al-Thowra General Hospital, Al-Jumhori Teaching Hospital, and Military General Hospitals Sana’a city. We used Kirby-Bauer disk diffusion method to detect antimicrobial susceptibility and establish the presence of ESBLs-producing bacteria according to the Clinical and Laboratory Standards Institute guidelines. Results: Out of 740 isolate, 233 (31.5%) were Escherichia coli followed by Staphylococcus aureus 188 (25.4%), Pseudomonas aeruginosa 149 (20.1%), Klebsiella sp. 107 (14.5%), Enterococcus faecalis 25 (3.4%) and Proteus spp. 38 (5.1%). The highest frequencies of ESBLs producing among Proteus sp. were Proteus mirabilis 26 out 38 (68.4%) and Proteus vulgaris 12 out 38 (31.6%). The most effective of antimicrobial susceptibility pattern among Proteus spp. were Imipenem (100%) followed by Pipracillin-Tazobactam (92.3%) for P. mirabilis and (83.3%) for P. vulgaris, while the Amikacin (80.8%) for P. mirabilis and P. vulgaris with (91.7%). Amoxicillin and Cefotaxime were the highest for both species (100%). Conclusion: The prevalence of ESBL-producing Proteus spp. detected in this study is of great concern for public health authorities and a strict adherence of infection control policies and procedures with continuous antibiotics resistance surveillance including antimicrobial management and routine detection of ESBL-producing isolates are very important to prevent nosocomial infections.