scholarly journals Beta-lactam antibiotics and extended spectrum beta-lactamases

2021 ◽  
Vol 9 (2) ◽  
pp. 015-024
Author(s):  
Vitus Silago

Extended spectrum beta-lactamases (ESBLs) are enzymes produced by bacteria, mostly members of the family Enterobacteriaceae commonly Escherichia coli and Klebsiella pneumoniae. ESBLs hydrolyze the beta-lactam ring of beta-lactam antibiotics making these antibiotics ineffective therefore rendering the bacteria resistance against beta-lactam antibiotics. The global upsurge of ESBLs producing bacteria causing both hospital and community acquired infections mostly urinary tract infections, pneumonia and bloodstream infections, threatens the effectiveness of infectious diseases treatment. ESBL families; TEM, SHV and CTX-M are globally disseminated and frequently detected in clinical isolates as well as colonization and contamination isolates. Various laboratory detection methods of ESBLs producing Gram negative bacteria are available. These methods; phenotypic methods, automated methods and molecular-based methods are varying in sensitivity and specificity, need of technical expertise, and rapidness. Therefore, they should be clearly understood before being employed for routine or research use for detection of ESBLs production among Enterobacteriaceae. In addition, understanding the mode of action and mechanisms of resistance to beta-lactam antibiotics, and the epidemiology of ESBLs producing bacteria is of paramount.

2021 ◽  
Author(s):  
Abdikarim Hussein Mohamed ◽  
Hussein Ali Mohamud

Abstract Background: Gram-negative enterobacteria are the most common cause of urinary tract infections. Cedecea is a new separate genus in the family enterobacteriaceae, and it is a very rare pathogen that was primarily found in the respiratory tract. Cedecea lapagei is a very rare pathogen of urinary tract infections. To the best of our knowledge, this is the first case report in the world reported in English literature. Case presentation: A 55 years old man with chronic renal failure, poorly controlled diabetes mellitus, and hypertension presented with acute exacerbations of renal failure and irritative voiding symptoms. After stabilization and empirical antibiotic therapy with Ceftriaxone, the patient’s condition was not improved and deteriorated progressively. After the request of urine culture, the culture was isolated, an extremely rare uropathogen recently recognized by the Centers for Disease Control and Prevention (CDC); the Cedecea lapagei. Cedecea lapagei identification had been done using Eosin methylene blue agar (EMB). Gram-negative lipase positive bacteria with bacillus in shape, motile in nature that is non-spore-forming, and non-encapsulated enterobacteria with the final result of >100,000 colony-forming units per ml of Cedecea lapagei were isolated. Mueller-Hinton agar had been used to perform antimicrobial sensitivity and resistance. The pathogen was extensively resistant to the extended-spectrum beta-lactamases antibiotics and extended-spectrum beta-lactam inhibitors while carbapenems, fluoroquinolones, aminoglycosides, and Trimethoprim-sulfamethoxazole showed a higher sensitivity rate. Conclusion: The treatment of Cedecea lapagei infections represents a challenging issue due to its multi-drug resistant and extensive drug resistance patterns to a variety of antimicrobial classes, such as extended-spectrum beta-lactamases, cephalosporins, and beta-lactam inhibitors. Antimicrobial treatment should be aligned with the culture findings once available.


2014 ◽  
Vol 8 (08) ◽  
pp. 954-960 ◽  
Author(s):  
Diego Borin Nóbrega ◽  
Marcelo Brocchi

Serious human and animal infections caused by bacteria are usually treated with beta-lactams. Extended-spectrum beta-lactamases (ESBLs) constitute the most clinically and economically important enzymes that are able to hydrolyze and inactivate beta-lactam antibiotics in veterinary medicine. The spread of ESBLs represents a serious threat to healthcare systems, drastically undermining therapeutic options. The relationship between drug usage and the emergence of resistance has been extensively reported. Nevertheless, the use of antimicrobials in veterinary medicine and the emergence of ESBLs in animals remains a matter of debate. Moreover, there is still controversy about whether antibiotic usage in farm animals poses a potential public health risk. This review will (i) deal with  aspects related to the presence of ESBLs in veterinary medicine, (ii) its link with human medicine, and (iii) discuss strategies to be implemented to preserve antimicrobial effectiveness. New insights relative to old questions concerning antimicrobial use in domestic animals are also presented.


2007 ◽  
Vol 51 (4) ◽  
pp. 1304-1309 ◽  
Author(s):  
Frédéric Robin ◽  
Julien Delmas ◽  
Cédric Schweitzer ◽  
Olivier Tournilhac ◽  
Olivier Lesens ◽  
...  

ABSTRACT Two clinical isolates of Escherichia coli, CF1179 and CF1295, were isolated from a patient hospitalized in the hematology unit of the University Hospital of Clermont-Ferrand, Clermont-Ferrand, France. They were resistant to penicillin-clavulanate combinations and to ceftazidime. The double-disk synergy test was positive only for isolate CF1179. Molecular comparison of the isolates showed that they were clonally related. E. coli recombinant strains exhibiting the resistance phenotype of the clinical strains were obtained by cloning. The clones corresponding to strains CF1179 and CF1295 produced TEM-type beta-lactamases with pI values of 5.7 and 5.3, respectively. Sequencing analysis revealed two novel bla TEM genes encoding closely related complex mutant TEM enzymes, designated TEM-151 (pI 5.3) and TEM-152 (pI 5.7). These two genes also harbored a new promoter region which presented a 9-bp deletion. The two novel β-lactamases differed from the parental enzyme, TEM-1, by the substitution Arg164His, previously observed in extended-spectrum beta-lactamases (ESBLs), and by the substitutions Met69Val and Asn276Asp, previously observed in the inhibitor-resistant penicillinase TEM-36/IRT-7. They differed by two amino acid substitutions: TEM-152 harbored a Glu240Lys ESBL-type substitution and TEM-151 had an Ala284Gly substitution. Functional analysis of TEM-151 and TEM-152 showed that both enzymes had hydrolytic activity against ceftazidime (k cat, 5 and 16 s−1, respectively). TEM-152 was more resistant than TEM-151 to the inhibitor clavulanic acid (50% inhibitory concentrations, 1 versus 0.17 μM). These results confirm the evolution of TEM-type enzymes toward complex enzymes harboring the two kinds of substitutions which confer an extended spectrum of action against beta-lactam antibiotics and resistance to inhibitors.


1997 ◽  
Vol 41 (5) ◽  
pp. 943-949 ◽  
Author(s):  
M T Nüesch-Inderbinen ◽  
F H Kayser ◽  
H Hächler

Sixty isolates of Enterobacteriaceae resistant to beta-lactam antibiotics were collected over a period of 2 years in Switzerland and screened by hybridization for the carriage of SHV genes. Thirty-four positive strains were found, and their SHV genes were amplified and sequenced. SHV extended-spectrum beta-lactamases (ESBLs) were found: 13 strains contained SHV-2a, 12 harbored SHV-2, and SHV-5 was found twice. Four strains were shown to contain SHV-1. In addition, we report two new SHV variants, termed SHV-11 (non-ESBL) and SHV-12 (ESBL). In spite of the carriage of SHV ESBLs, many strains showed only low resistance to one or more third-generation cephalosporins. In addition, 26 did not transfer the blaSHV gene in mating experiments.


2020 ◽  
Vol 13 (3) ◽  
pp. 135-140
Author(s):  
HauwaYakubu ◽  
Mahmud Yerima Iliyasu ◽  
Asma’u Salisu ◽  
Abdulmumin Ibrahim Sulaiman ◽  
Fatima Tahir ◽  
...  

Carbapenemases are microbial enzymes that confer resistance to virtually all available beta-lactam antibiotics and the most frequent carbapenemases are the Klebsiella pneumoniae Carbapenamase (KPC). Detection of carbapenemases is a significant infection control strategy as the enzymes are often associated with extensive antimicrobial resistance, therapeutic failures and mortality associated with infectious diseases. A total of 400 clinical samples were collected from different groups of patients in Abubakar Tafawa Balewa University Teaching Hospital, Bauchi, Nigeria and 118 K. pneumoniae were isolated using standard microbiological techniques. The isolates were subjected to antibiotic susceptibility testing by Kirby-Bauer disc diffusion method, then screened for Carbapenamase production using modified Hodge test. The results indicated that the isolates were resistant to Ampicillin (61.9%), Ceftriaxone (50.8%) and Ceftazidime (50.8%), then Ciprofloxacin (54.2%), but predominantly sensitive to Imipenem (66.9%), Eterpenem (60.2%) and Meropenem (65.3%). It was found that 38 (32.2%) of the isolates phenotypically shows the presence of Carbapenamase, with highest frequency of (40.7%) among patients, mainly adult females with cases of Urinary Tract Infections (UTIs) and the least from wound (11.8%).This study revealed that the isolates produced other beta-lactamases than KPC or variants of Carbapenamase that cannot be detected by modified Hodge test, thus shows low resistance to carbapenems. Therefore further studies is needed to genotypically confirm the presence of KPC in these isolates.


2021 ◽  
Vol 37 (2) ◽  
pp. 56-73
Author(s):  
F Iseghohi ◽  
J.C Igwe ◽  
M Galadima ◽  
A.F Kuta ◽  
A.M Abdullahi ◽  
...  

Globally, urinary tract infections are one of the most common infections in need of urgent clinical attention. The prevalence of extended spectrum beta-lactamases (ESBL)- producing Escherichia coli isolated from urine samples of some UTI patients and s of apparently healthy individuals in Minna, Nigeria, is investigated. Standard microbiological techniques were used to conduct this study. A total of 170 catch midstream urine samples submitted to the Medical Microbiology Laboratories of 4 different hospitals (and samples from healthy individuals) were randomly collected for 5 months and examined for microbial growths. Female patients (65.9%) submitted more urine samples for UTI test than their male counterpart (34.1%). The age ranges of 21 -30 (26.5%) and 31 - 40 (25.3%) had the highest percentages of infection rate while those within the ages 1- 10 (3.5%) and ≥ 71 (2.3%) were the least infected. This study observed a prevalence of 23.5% of E. coli in Minna metropolis and a significant number (30%) of healthy individuals (HI) was observed to harbor the E. coli in their urine. The isolates were highly susceptible to Gentamicin (65%), Ofloxacin (65%), Tetracycline (62.5%), Cotrimoxazole (62.5%), and Streptomycin (57.5%). Mildly susceptible to Pefloxacin (37.5%), Chloramphenicol (37.5%), and Ciprofloxacin (35%). There were significant resistance to most of the beta-lactames tested [Cefuroxime (80%), Amoxicillin (42.5%), Augmentin (40), Cefotaxime (20%) and Ceftaxidime (7.5%)]. Two of the isolates were resistant to all the 13 antibiotics tested; 70% (28) of the isolates had multiple antibiotics resistance index (MARI) ≥0.3. Multidrug resistance was expressed in 37.5% of the isolates tested. The study showed a vast resistant pool in the environment. Only 25% of the E. coli isolated from the urine samples produced beta-lactamases phenotypically, most of which expressed resistance to more than 5 of the antibiotics tested and had MARI of ≥ 0.5. Further evaluation showed that 25% (10/40) of the E. coli isolated from the UTI patients in Minna, Nigeria, were ESBL- producers and could harbor one or two of the genes. TEM gene was expressed in 70% (7) of the isolates that produced ESBL phenotypically, 60% 6) harbored CTXM gene, 20% (2) had the OXA gene while none of the bacteria harbored the SHV gene. The study established a 5.9% ESBL prevalence among the E. coli isolated from UTI in the environment studied. This study established that E. coli is one of the prevalent bacteri urea majorly isolated from UTI patients in Minna. The prevalent E. coli are multidrug resistant and could harbor more than one ESBL gene . keywords: Escherichia coli, Minna, UTI, ESBL, Multidrug resistance


2021 ◽  
Vol 25 (2) ◽  
pp. 234-245
Author(s):  
A. V. Bardasheva ◽  
N. V. Fomenko ◽  
T. V. Kalymbetova ◽  
I. V. Babkin ◽  
S. O. Chretien ◽  
...  

72 clinical strains of Klebsiella spp. isolated from samples obtained from humans in Novosibirsk, Russia, were analyzed. Species identification of strains was performed using 16S rRNA and rpoB gene sequences. It was revealed that Klebsiella pneumoniae strains were dominant in the population (57 strains), while the remaining 15 strains were K. grimontii, K. aerogenes, K. oxytoca and K. quasipneumoniae. By molecular serotyping using the wzi gene sequence, K. pneumoniae strains were assigned to twenty-one K-serotypes with a high proportion of virulent K1- and K2-serotypes. It was found that K. pneumoniae strains isolated from the hospitalized patients had a higher resistance to antibiotics compared to the other Klebsiella species. Real-time PCR revealed that the population contained genes of the blaSHV, blaTEM, blaCTX families and the blaOXA-48 gene, which are the genetic determinants of beta-lactam resistance. It has been shown that the presence of the blaCTX sequence correlated with the production of extended-spectrum beta-lactamases, and phenotypic resistance to car-bapenems is due to the presence of the blaOXA-48 gene. At the same time, the carbapenemase genes vim, ndm, kpc, imp were not detected. Among the aminoglycoside resistance genes studied, the aph(6)-Id and aadA genes were found, but their presence did not always coincide with phenotypic resistance. Resistance to fluoroquinolones in the vast majority of strains was accompanied by the presence of the aac(6’)-IB-cr, oqxA, oqxB, qnrB, and qnrS genes in various combinations, while the presence of the oqxA and/or oqxB genes alone did not correlate with resistance to fluoroquinolones. Thus, the detection of blaCTX and blaOXA-48 can be used to quickly predict the production of extended-spectrum beta-lactamases and to determine the resistance of Klebsiella to carbapenems. The detection of the aac(6’)-Ib-cr and/or qnrB/qnrS genes can be used to quickly determine resistance to fluoroquinolones.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammad Sadegh Rezai ◽  
Ebrahim Salehifar ◽  
Alireza Rafiei ◽  
Taimour Langaee ◽  
Mohammadreza Rafati ◽  
...  

Escherichia coliremains as one of the most important bacteria causing infections in pediatrics and producing extended-spectrum beta-lactamases (ESBLs) making them resistant to beta-lactam antibiotics. In this study we aimed to genotype ESBL-producingE. coliisolates from pediatric patients for ESBL genes and determine their association with antimicrobial resistance. One hundred of theE. coliisolates were initially considered ESBL producing based on their MIC results. These isolates were then tested by polymerase chain reaction (PCR) for the presence or absence ofCTX,TEM,SHV,GES, andVEBbeta-lactamase genes. About 30.5% of isolatedE. coliwas ESBL-producing strain. TheTEMgene was the most prevalent (49%) followed bySHV(44%),CTX(28%),VEB(8%), andGES(0%) genes. The ESBL-producingE. coliisolates were susceptible to carbapenems (66%) and amikacin (58%) and showed high resistance to cefixime (99%), colistin (82%), and ciprofloxacin (76%). In conclusion, carbapenems were the most effective antibiotics against ESBl-producingE. coliin urinary tract infection in North of Iran. The most prevalent gene is the TEM-type, but the other resistant genes and their antimicrobial resistance are on the rise.


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