Presence Of Integrons Research Articles

High Prevalence of Transferable Integron-Associated Drug Resistance in Escherichia coli Strains Isolated from Blood Cultures in a University Hospital in xxxxxxxx, xxxxxxxx

Objective: In this study, we aimed to determine the the presence of transferable integron-associated drug resistance in Escherichia coli strains isolated from the blood cultures of patients with various infections at the Research and Application Center (………Hospital) of …………….., …………….., ……………... Methods: The presence of integrons was determined by integron-specific polymerase chain reactions, and the amplicons were analyzed by DNA sequencing. Plasmid transfer assays were carried out by the broth mating method. The clonal relationship of integron-containing strains was evaluated by pulsed-field gel electrophoresis (PFGE). Results: Resistance rates to the antibiotic groups used were between 0.9% to 63%. Thirty-eight (34,2%) strains contained class 1 integrons carrying dfrA7, dfr17-aadA5, dfrV, dfrA1-aadA1, and dfrA12-aadA2 gene cassette arrays. Seven (6,3%) strains contained class 2 integrons having dfrA1-sat2-aadA1 and dfrA1-sat2-aadA30 gene cassette arrays. Twenty-two conjugative resistance plasmids were harbored in integron-carrying isolates, and three of them were found to be in the IncN group. Four strains carrying class 1 integrons which were isolated from different clinics showed clonally similar patterns in PFGE analysis. Conclusion: We conclude that about 50% E. coli isolates in our hospital carry integron-associated transferable drug resistance, and may play a crucial role in horizontal dissemination. Further molecular epidemiological investigations are required in regard to explaining the relationship between the carriage of integrons in E. coli strains of blood origin in this hospital as well as countrywide.

Prevalence and characterization of quinolone resistance and integrons in clinical Gram-negative isolates from Gaza strip, Palestine.

Gram-negative bacteria with quinolone resistance and extended-spectrum beta-lactamases (ESBLs) present significant treatment challenges. This study evaluated the prevalence and characteristics of quinolone resistance in Gram-negative strains, investigating the relationship between plasmid-mediated quinolone resistance (PMQR), ESBLs, and integrons. We collected 146 Gram-negative isolates from patients in three Palestinian hospitals. For quinolone resistance isolates, the presence and characterization of PMQR, β-lactamase genes and integrons were studied by PCR and sequencing. Out of 146 clinical isolates, 64 (43.8%) were resistant to quinolones, with 62 (97%) being multidrug-resistant (MDR) and 33 (51.5%) ESBL-producers. PMQR-encoding genes were present in 45 (70.3%) isolates, including aac(6')-Ib-cr (26.6%), qnrA (18.8%), qnrS1 (20.8%), and qnrB (6.4%). BlaCTX-M genes were detected in 50% (32/64) of isolates, with blaCTX-M-15 being the most common. BlaTEM-1, blaSHV-1 and blaVIM genes were found in 13, 6, and 4 isolates, respectively. Class I integrons were found in 31/64 (48%) of isolates, with 14 containing gene cassettes conferring resistance to trimethoprim (dhfr17, dfrA12, dfrA1) and aminoglycosides resistance genes (aadA1, aadA2, aadA5, and aadA6). This study found a high rate of quinolone resistance, ESBL and integrons in clinical Gram-negative isolates from our hospitals. Urgent measures are crucial, including implementing an antimicrobial resistance surveillance system, to control and continuously monitor the development of antimicrobial resistance.

Integrons and multidrug resistance across phylogenetic groups of clinical isolates of Escherichia coli.

This study was aimed to investigate the multidrug resistance patterns in clinical isolates of Escherichia coli and their correlation with integrons and phylogenetic groupings. A total of 37 clinical E. coli isolates were evaluated for drug resistance patterns by disk diffusion method. Phylogenetic groupings and the presence of integrons among E. coli were determined by multiplex PCR assays. Multidrug resistance was identified in 84% of the clinical isolates of E. coli with higher resistance found against cephalosporins (94.6%) and fluoroquinolones (83.8%), while lower resistance was observed against polymyxins (24.3%) and carbapenems (29.7%). Metallo-β-lactamases were found in all carbapenem resistant isolates. The phylogenetic group B2 was the most dominant (40.5%), followed by groups A (35.1%), D (13.5%) and B1 (10.8%). Integrons were detected in 25 (67.6%) isolates and intI1, intI2, and intI3 genes were found in 62.2%, 18.9% and 10.8% of isolates respectively. Our results show that phylogenetic classification of E. coli is not relevant with antimicrobial resistance. However, there was strong association between the integron classes and resistance against β-lactam and fluoroquinolones antimicrobials. Additionally, this study highlighted that the presence of integrons plays a crucial role in the development of multidrug resistance in clinical isolates of E. coli. Most significantly, this is the first report of detection of three classes of integron among clinical isolates of E. coli in Pakistan.

Presence of integrons and their correlation with multidrug resistance in Salmonella enterica serovar Typhimurium: Exploratory systematic review

In Salmonella enterica serovar Typhimurium (Typhimurium), multidrug resistance is associated with integrons carrying resistance genes dispersed by mobile genetic elements. This exploratory systematic review sought to identify integron types and their resistance genes in multidrug resistance Typhimurium isolates. We used Medline, PubMed, SciELO, ScienceDirect, Redalyc, and Google Scholar as motor searchers for articles in Spanish or English published between 2012 and 2020, including the keywords “integrons”, “antibiotic resistance”, and “Salmonella Typhimurium”. We included 38 articles reporting multidrug resistance up to five antibiotic families. Class 1 integrons with aadA2 and blaPSE-1 gene cassettes were predominant, some probably related to the Salmonella genomic island 1. We did not find studies detailing class 1 and 2 integrons in the same isolate, nor class 3 integrons reported. The presence of integrons largely explains the resistance profiles found in isolates from different sources in 15 countries.

Evaluation of the presence of integrons, sul and smqnr genes and the prevalence of antibiotic resistance in Stenotrophomonas maltophilia clinical isolates

ObjectivesThe objective of this investigation was to examine the mechanisms associated with antibiotic resistance in Stenotrophomonas maltophilia clinical isolates retrieved from hospitalized patients undergoing open heart surgery in a Heart Center located in Tehran, Iran. Materials and methodsThis investigation encompassed a cross-sectional study of 60 S. maltophilia isolates, which were procured from diverse clinical specimens. Primary identification of the isolates was conducted through conventional microbiologic methods and subsequently verified by means of PCR primers. The E-test was utilized to establish the minimum inhibitory concentrations (MICs). PCR was then employed to ascertain the antibiotic resistance genes (sul1, sul2, Smqnr and intl1 - intl3). ResultsIn this study, a total of sixty clinical isolates of S. maltophilia were collected, with the majority of them being obtained from Intensive Care Units (ICU) (n = 54; 90%). The disk diffusion method yielded results indicating that 55% of the isolates were sensitive to minocycline, whereas 30% were intermediate and 15% were found to be resistant. Additionally, the MIC results revealed that the resistant rates of the isolates towards ceftazidime, cotrimoxazole and levofloxacin were 46.7%, 1.7% and 5%, respectively. The PCR amplification of three classes of integrons genes indicated that fifteen (25%) of the isolates carried int1, while no detection for intl2 and intl3 was reported. Furthermore, the prevalence of antibiotic resistance genes (sul1, sul2, and Smqnr) was identified in 15 (25%), 6 (10%), and 28 (46.7%) isolates, respectively. ConclusionThe reported increasing rate of antibiotic resistance and mobile genetic elements that could extend the resistance genes to other strains in the hospital, finally it could be an alarming issue for healthcare settings that need special attention to this strain and the epidemiological study on this issue.

VIM-type metallo-β-lactamase (MBL)-encoding genomic islands in Pseudomonas spp. in Poland: predominance of clc-like integrative and conjugative elements (ICEs).

To characterize VIM-type metallo-β-lactamase (MBL)-encoding genomic islands (GIs) in Pseudomonas aeruginosa and P. putida group isolates from Polish hospitals from 2001-2015/16. Twelve P. aeruginosa and 20 P. putida group isolates producing VIM-like MBLs were selected from a large collection of these based on epidemiological and typing data. The organisms represented all major epidemic genotypes of these species spread in Poland with chromosomally located blaVIM gene-carrying integrons. The previously determined short-read sequences were complemented by long-read sequencing in this study. The comparative structural analysis of the GIs used a variety of bioinformatic tools. Thirty different GIs with blaVIM integrons were identified in the 32 isolates, of which 24 GIs from 26 isolates were integrative and conjugative elements (ICEs) of the clc family. These in turn were dominated by 21 variants of the GI2/ICE6441 subfamily with a total of 19 VIM integrons, each inserted in the same position within the ICE's Tn21-like transposon Tn4380. The three other ICEs formed a novel ICE6705 subfamily, lacking Tn4380 and having different VIM integrons located in another site of the elements. The remaining six non-ICE GIs represented miscellaneous structures. The presence of various integrons in the same ICE sublineage, and of the same integron in different GIs, indicated circulation and recombination of the integron-carrying genetic platforms across Pseudomonas species/genotypes. Despite the general diversity of the blaVIM-carrying GIs in Pseudomonas spp. in Poland, a clear predominance of broadly spread and rapidly evolving clc-type ICEs was documented, confirming their significant role in antimicrobial resistance epidemiology.

Integron distribution and relationship to antimicrobial resistance in E. coli isolated from blood culture

PurposeThe aim of this study was to evaluate the distribution of integrons in strains of E. coli isolated from blood culture and the relationship between integrons and antimicrobial resistance. MethodsThe study included 100 E. coli strains sent to the Medical Microbiology Laboratory from different clinics between September 2022 and June 2023. Antibiotic susceptibility was evaluated according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST). The presence of integrons was determined by the inhouse polymerase chain reaction (PCR). ResultsIntegron positivity was detected in 45 (45%) of isolates, and class 1 integrons were found in 41 (41%), class 2 integrons in 2 (2%), and both class 1 integrons and class 2 integrons in 2 (2%). Class 3 integron positivity was not detected. In total, 63 cases of community origin and 37 cases of hospital origin were identified. When antibiotic resistance was evaluated, the highest sensitivity was noted for amikacin (1%), meropenem (5%), imipenem (6%), and the highest resistant antibiotics were ampicillin (82%), cepfuroxime sodium (65%), and amoxicillin/clavulanate (62%), respectively. Of the 16 antimicrobial substances evaluated, 10 had an antibiotic resistance rate of over 45%. In class 1 integron-positive samples, ampicillin resistance and trimethoprim/sulfamethoxazole resistance were higher than in negative samples (p = 0.02, p = 0.0001, respectively). Fifty-one (51%) samples were found to have multiple drug resistance (MDR). In total, 59.5% of hospital-acquired isolates and 46% of community-acquired isolates were considered to be MDR. The class 1 integron positivity in MDR samples was high (p = 0.038). ConclusionThe high MDR rates in both hospital-acquired and community-acquired isolates are alarming. In particular, class 1 integron monitoring is very important to prevent the spread of MDR isolates.

Characterization of integrons, extended spectrum beta lactamases and genetic diversity among uropathogenic Escherichia coli isolates from Kerman, south east of Iran.

The study aimed to investigate the distribution of genes encoding integrons, extended spectrum beta-lactamase (ESBL) in E. coli isolated from UTIs, as well as the genetic diversity among the isolates. E. coli isolates were recovered from the patients with UTI in Kerman Iran. Antibiotic susceptibility was done according to CLSI guidelines. The presence of ESBL genes and integrons was evaluated using PCR. PCR and sequencing were applied for the evaluation of cassette content of integrons. Genotyping of the isolates was performed by multiple-locus variable-number tandem repeat analysis (MLVA). Imipenem was the most effective antibiotic, while the highest resistance was observed to streptomycin. In total 40.2% of isolates were ESBL producers. Of 69 integron-positive isolates, 59 only had class I integrons, 4 only had class II integrons and 6 had both types. The most common gene cassette found within class I integrons was dfrA17-aadA5 (n=27). The E. coli isolates were divided into 16 MLVA clusters. The current study demonstrated the simultaneous presence of class I integrons and ESBLs involved in the resistance of UPEC isolates to antibacterial agents. Our finding also revealed that the E. coli isolates belonged to diverse clones.

Mobile genetic elements profiling, gene flow, and antimicrobial susceptibility profiles, among Pseudomonas aeruginosa isolates, isolated from Al Muthanna hospitals' wound and burn units in Iraq

The prevalence assessment of integrons among multidrug-resistant strains of Pseudomonas aeruginosa receives much-needed attention from this study, as we achieved our desired objective by conducting a thorough analysis on one hundred swabs obtained from burn and clinical cases at the hospitals present in Al Muthanna governorate during November of the year 2021 through to March of the year 2022. By implementing various methodologies encompassing the scrutiny of growth traits and cellular composition as well as executing biochemical assays, a total of 55 isolates were determined to exhibit the existence of P. aeruginosa.When cultured in Hifluoro agar media, Pseudomonas aeruginosa produced diverse hues; particularly noticeable was its blue-green colour. It was discovered through investigation that there were no intI2 and inti3 genes present in those isolated. Findings from this research disclosed that about one-fifth, or precisely twelve out of fifty-five P. aeruginosa strains screened, had an actively expressed Integrase I gene. The association between elevated rates of resistance to multiple antimicrobial agents and the existence of integrons is worth mentioning. Furthermore, the assemblage of isolates that were efficacious in the presence of integrons demonstrated an augmented resistance towards several frequently employed antibiotics like rifampicin and ceftazidime. In conclusion, it can be stated with confidence that a considerable occurrence of integrons can be observed in Pseudomonas aeruginosa strains that display resistance to numerous pharmaceutical agents. Additionally, the discovery of the intI1 gene in a considerable proportion of isolates underscores the effectiveness of integrons in conferring resistance to a variety of antimicrobial agents. These revelations supplement our insight into antibiotic-resistant mechanisms while also underscoring the necessity for viable strategies aimed at halting and preventing bacterial drug resistance.

Comparison of Antimicrobial Susceptibility of Escherichia Coli Isolated from Fecal Poultry and Bovine Housed in Tunisian Farms; Phylogroup Diversity and Detection of Tetracycline and Sulfonamides Resistant Genes With Integron Class1

Little detailed documentation researched the excessive use of antimicrobials such as tetracycline and sulfonamides in veterinary medicine in Tunisia and more studies are needed. A total of 58 of commensal Escherichia coli isolates recovered from fecal samples of healthy poultry (n=31) and bovin (n=27) recovered from farms in Tunisia were examinated for 20 antimicrobial as well as, researched the presence of integron, variable regions (VRs), phylogroupes, tetracycline (tetA, tetB et tetC) and sulfonamides(sul1, sul2, sul3) resistance genes. The most frequently resistance in poultry origin were to tetracycline (94.3%), sulfonamide (70.69%), nalidixic acid (61.29), amoxicillin (58%), to trimthetoprim-sulfamethoxazole and streptomycin with the same rate (64.51%), ticarcilline (58%). Whereas, the bovine isolates were most resistant to streptomycin (55.5%), to amoxicillin (18.5), to tetracycline (37%), and have a moderate same rates to kanamycine, to trimthetoprim-sulfamethoxazole 11.11, to nalidixic acid and to sulfonamide 7.4%, For poultry and bovine class 1 integron were detected in 20, 6 isolates, respectively as well as class 2 integron were found in 2 and 1 isolates, respectively. Class 1 integrons were significantly associated with poultry origin (p=0.001). For poultry sul1, sul2, and sul3 genes were detected in 14 (46.2 %), 7 (23.8 %), and 4 (8.9 %) resistant isolates, respectively. Whereas, for bovine 5 isolates were resistant to sulfonamide and sul1 and sul2 genes were detected in 4 and 1 isolates with absence of sul3 genes. and tetracycline genes tetA, tetB genes were observed in 27 (84.37 %) and 8 (25%) resistant isolates, respectively while, TetC was not detected amongst our isolates. Seven arrangement gene cassette were detected; dfrA1-satA1-aadA1 in one identical DNA fragments with approximate size of 2000 bp and six arrangements of resistance gene cassettes of class 1 integron were detected; dfrA1+aadA1 (5isolates); for dfrA17+aadA1, dfrA12+ orfF+aadA2 each one two 2isolates; one isolate for aadA1 and dfrA5, respectively. In poultry, 16 isolates were found to belong to phylogroup A (sub- groupA1: 12, sub- groupA0: 4); 9 to B1, 1 to B2 and 5 to phylogroup D. However, in bovine 9 isolates have the phylogroups A1, 7 isolates B1, 4 isolates B2, and 3 isolates found to phylogroup D. Our results showed that the prevalence of resistance in E. coli isolates from poultry was much higher than that in bovin.

Comparative study on genotypic properties of Pseudomonas aeruginosa isolated from subclinical mastitis in Türkiye

The results of antibacterial therapy in mastitis may be related to not only the antibiotic sensitivity of the etiological factors, but also to their abilities carrying integron and virulence genes. Integrons are mobile DNA element that can capture and carry genes, particularly those responsible for antibiotic resistance. Pseudomonas aeroginosa has numberless virulence factors which are contributed to bacterial invasion and toxicity. The aim of this study is to investigate antibiotic resistance, integron and virulence gene profiles of P. aeruginosa isolates obtained from cow milk with subclinical mastitis; further, was to evaluate the relationship between the antimicrobial resistance of bacteria with the of integron and virulence gene carrying. Material of the study is consisted with 32 (9.8%) of P. aeruginosa isolates obtained from 326 subclinical mastitic milk samples. After the bacterial identification was done by classical conventional methods, polymerase chain reaction (PCR) was used to verify the genus and species identifications of the isolates and to determine the integron and virulence gene profiles. Using disk diffusion method, antimicrobial resistance was determined to fifteen antibiotics against belonging to eleven antimicrobial families. The relationship the presence of integron and virulence genes associated with antibiotic resistance, further the relationship the presence of virulence genes and antimicrobial resistance was calculated with the Chi-Square (χ2) test. Ten of virulence genes (lasl, lasR, lasB, rhll, rhlR, rhlAB, plcH, plcN, ppyR, exoT) were found in all isolates whilst a virulence gene (aprA) was not present in any isolate. It was found that 34.4% of the isolates carried any integron gene. The results showed that the relationship is important between the presence of int genes and gentamicin, amikacin, tetracycline, cefoperazone, imipenem, aztreonam, ciprofloxacin, enrofloxacin resistance and exoU virulence gene presence. Also; there were also important associations between resistance to certain antibiotics and the presence of P. aeroginosa virulence genes: ciprofloxacin with lasA; netilmicin, cefoperazone and ciprofloxacin with pilB; netilmicin and ciprofloxacin with pelA; amikacin with algD, algU, algL; aztreonam with toxA; enrofloxacin with pvdA. All isolates obtained in this study showed multiple antibiotic resistance (MDR). In these cases, the presence of integron and some virulence genes could play a prominent role in the resistance of P. aeroginosa isolates to antimicrobial drugs. This study could be important in that it is the first study to show the presence of integrons and virulence genes in P. aeroginosa isolates originating from mastitic cow milk in Turkey. The presence of antibiotic-resistant P. aeroginosa strains in cattle farms may also pose a public health risk, as these bacteria can transmit their resistance genes to humans through food consumption.

Prevalence and resistance to antibacterial agents in Salmonella enterica strains isolated from poultry products in Northern Kazakhstan.

Salmonella is one of the main causative agents of foodborne infections. The source of the pathogen, in most cases, is poultry products. The intensification of poultry farming and the constant and uncontrolled use of antimicrobials has led to an increase in the level of antibiotic resistance, especially in developing countries. This study aimed to determine the level of sensitivity to antimicrobial agents in Salmonella enterica strains isolated from poultry products in Northern Kazakhstan, as well as to determine the genetic mechanisms of resistance and the presence of integrons. In total, 398 samples of poultry products sold in Northern Kazakhstan were selected. Salmonella strains were isolated from product samples using microbiological methods. Salmonella was identified based on morphological, biochemical, and serological methods, as well as polymerase chain reaction (PCR). Sensitivity testing for antimicrobial agents was performed using the disk diffusion method. The detection of resistance genes was performed using PCR and gel electrophoresis. Out of 398 samples of poultry products, a total of 46 Salmonella isolates were obtained. Most of the isolates belong to the serovar Salmonella Enteritidis (80.4%). The assessment of sensitivity to antibacterial agents showed that Salmonella was mainly resistant to nalidixic acid (63%), furadonin (60.9%), ofloxacin (45.6%), and tetracycline (39.1%). In 64.3% of cases, Salmonella was resistant to three or more groups of antibacterial agents. Resistance genes such as tetA, tetB, blaTEM, aadA, sul3, and catII, as well as integrons of two classes (teg1 and teg2), were identified. Poultry products contain antimicrobial-resistant strains of Salmonella, as well as genes encoding resistance mechanisms. The results emphasize the need for constant monitoring of not only pathogenic microorganisms but also their sensitivity to antimicrobial agents. The potential threat to human health requires a unified approach to the problem of antibiotic resistance from representatives of both public health and the agroindustrial complex.

The linkage between prevalence of integron I and reduced susceptibility to biocides in MDR Klebsiella pneumoniae isolated from neonates.

Klebsiella pneumoniae causes challenging nosocomial fatal infections including neonatal sepsis. Our study aims at clarifying the contribution of integrons in the observed reduced susceptibility of multidrug-resistant (MDR) K. pneumoniae isolated from septicemic neonates to the clinically used antimicrobial agents and biocides. Eighty-six K. pneumoniae isolates were collected from Mansoura University Children's Hospital from septicemic neonates. Isolates were subjected to antibiotic and biocide susceptibility using disk diffusion and the agar dilution method, respectively. The distribution of different classes of integrons was screened in the isolates by PCR. Detected inegron I was sequenced in selected isolates. Fifty-seven isolates (66.27%) were MDR. In the MDR isolates, class I integron was detected in 23 (40.3%), integron III was detected in 20 (35%), whereas integron II could not be detected. Sequencing results of integron I from MDR K. pneumoniae isolates revealed that only aminoglycoside and folate synthesis inhibitors gene cassettes were detected, while the rest of the resistance genes were not associated with integron I. The presence of integron I in MDR K. pneumoniae tested isolates may contribute only to some biocide resistance, however, it does not seem to be the only contributor in multiple drug resistance.

Carbapenem and Colistin Resistance, Integrons and Plasmid Replicon Types in Multi-Drug Resistant Klebsiella Strains Isolated in Turkey.

Multidrug-resistant (MDR) Klebsiella is a globally important nosocomial pathogen. In the present study, 101 multidrug-resistant Klebsiella strains isolated from various clinical specimens obtained from two different Medical Faculties' hospitals were involved. We aimed to find out the prevalence of carbapenemase, mobile colistin resistance genes, and integrons in MDR Klebsiella strains. The antibiotic susceptibilities of strains were determined by Kirby Bauer disc-diffusion method and resistance to colistin was confirmed by detection of minimum inhibitory concentrations. The prevalence of carba-penemase genes (blaOXA-48, blaNDM, blaIMP, blaVIM, blaKPC), mobile colistin-resistance genes (mcr-1 and mcr-2), and integrons (class I, II and III) were examined in Klebsiella strains by polymerase chain reaction. All strains were resistant to β-lactam antibiotics, carbapenems, and quinolones. On the other hand, only nine (8.9%) strains were resistant to colistin. The most common carbapenemase genes were blaNDM (64.3%) and blaOXA-48 (53.5%). Besides, 28 (27.7%) strains were found to harbor both blaNDM and blaOXA-48. These 28 strains be-longed to the IncA/C (18.7%), IncL/M (7.7%), and IncFIIs (1.1%) plasmid replicon types. No strain was positive for blaIMP, mcr-1, and mcr-2. Class I and Class II integrons were shown to be harbored in 83.2% and 63.3% of strains, respectively. In total, 63 (63.6%) of strains harbored both classes I and II integrons. Class III integron was not detected. There was a statistically significant relationship between the presence of integrons and antibiotic resistance for cefotaxime (p = 0.024), ciprofloxacin (p < 0.001) trimethoprim/sulfamethoxazole (p < 0.001) and levofloxacin (p = 0.002). To our knowledge, this study represents the first report of a human isolate for the co-presence of blaNDM, blaOXA-48 and both Class I and Class II integrons, from Turkey. Our findings also highlight the dissemination of integrons and carbapenemases and the importance of surveillance on emerging antibiotic resistance.

Antimicrobial resistance patterns and virulence gene profiles of Salmonella enteritidis and Salmonella typhimurium recovered from patients with gastroenteritis in three cities of Iran.

This study evaluated distribution of virulence factors and antibiotic resistance in clinical isolates of Salmonella enteritidis and Salmonella typhimurium in three cities of Iran. Altogether 48 S. enteritidis and S. typhimurium isolates were collected from patients at certain Iranian hospitals between May 2018 and September 2021. Antimicrobial susceptibility testing was performed by disk diffusion and broth microdilution methods. The presence of antibiotic-resistance genes (blaTEM,blaSHV,blaCTX-M,blaNDM,strA, strB, aadA1, tetA, tetB, floR, sul1, sul2, dfrA), integrons (classe 1 and 2), and virulence-associated genes (invA, stn, sopB, spvC, rck, phoPQ) was investigated by PCR and sequencing. Antimicrobial agents like trimethoprim-sulfamethoxazole and imipenem represent highly efficient agents with 97% susceptibility. S. enteritidis and S. typhimurium exhibited high resistance to ciprofloxacin (n = 20, 71.43%) and ceftazidime (n = 9, 45%), respectively. Overall, 3 (6.25%), 13 (27.08%), and 6 (12.5%) isolates were divided into strong, moderate, and weak biofilm producers, respectively. Moreover, blaCTX-M,blaTEM, blaSHV, sul1, sul2, tetA, tetB, floR, strA, and strB resistant genes were detected in 10 (20.8%), 5 (10.4%), 1(2.08%), 7 (14.58%), 1 (2.08%), 3 (6.25%), 2 (4.1%), 1 (2.08%), 2 (4.1%), 2 (4.1%), respectively. Furthermore, 7 (14.58%) strains had classe 1 integron. All tested S. enteritidis strains had invA and sopB, and all S. typhimurium strains had invA and phoPQ. However, spvC remained undetected in all isolates. Extensive surveillance and efficient control measures against infection help to stop the upsurge of various antibiotic-resistant isolates.

Antibiotic resistance and carriage class I integron in clinical isolates of Acinetobacter baumannii from Al Muthanna, Iraq.

The goal of this work was to systematically characterize and detect class 1, 2, and 3 integrons with many antibiotic resistance A. baumannii strains collected from a clinical environment in Iraq's Al-Muthanna hospitals. In this investigation, 24 non-replicated clinical strains of A. baumannii were evaluated using Chrome agar as a selective medium and PCR of the rplB gene. The clonal relatedness of the isolates to class 1 integron was evaluated using a PCR technique. The prevalence of class 1 integron was detected by PCR in only 12 clones of A. baumannii followed by HinfI digestion analysis showing three identical bands at 160 bp, 1350 bp, and 870 bp. In addition, PCR sequencing confirmed the presence of gene cassette arrays consisting of aacA4-catB8-aadA1 (100%) in class 1 integron. The sequence analysis of the integron shows 97.87 identity with A. baumannii isolates from Australia (GenBank accession number CP054302) among A. baumannii isolates. The blast analysis of this class I integron showed that the presence of the intI1, aacA4-catB8-aadA1 genes can considerably boost the acquisition of MDR phenotypes in A. baumannii isolates. We concluded that antibiotics of many types are widely used. The presence of integrons in A. baumannii is concerning for public health. In the clinical setting, it appears that the class 1 integron can be used as a predictive biomarker for the presence of MDR phenotypes. In these bacteria, however, the integron does not possess carbapenemases genes.

First study on virulence genes, antimicrobial resistance, and integrons in Escherichia coli isolated from cage, free-range, and organic commercial eggs in Phayao Province, Thailand.

Antimicrobial resistance (AMR) is a global problem that affects human and animal health, and eggs can act as a vehicle for pathogenic and non-pathogenic resistant bacteria in the food chain. Escherichia coli is an indicator of food contamination with fecal materials as well as the occurrence and levels of AMR. This study aimed to investigate the presence of AMR, integrons, and virulence genes in E. coli isolated from eggshell samples of three egg production systems, from supermarkets in Thailand. A total of 750 hen's egg samples were purchased from supermarkets in Phayao Province: Cage eggs (250), free-range eggs (250), and organic eggs (250). Each sample was soaked in buffered peptone water (BPW), and the BPW samples were incubated at 37°C for 18-24 h. All samples were tested for E. coli by the standard conventional culture method. Then, all identified E. coli were tested for antimicrobial susceptibility to 15 antimicrobial agents by the agar disk diffusion method. All E. coli strains were subsequently found to have virulence genes and Classes 1 and 2 integrons by polymerase chain reaction. Among the eggshell samples, 91 samples were identified as having E. coli (cage eggs, 24 strains; free-range eggs, 27 strains; and organic eggs, 40 strains). Then, among the E. coli strains, 47 (51.6%) were positive for at least one virulence gene. The proportion of AMR in the eggshell samples was 91.2% (83/91), and streptomycin (STR), ampicillin (AMP), and tetracycline (TET) had a high degree of resistance. Among the E. coli strains, 27 (29.7%) strains were positive for class 1 or 2 integrons, and integron-positive strains were commonly found in STR-, AMP-, and TET-resistant strains. Multidrug resistance (MDR) was detected in 57.1% (52/91) of the E. coli strains, with STR-AMP-TET (5.5%) as the most frequent pattern. The proportion of MDR in cage eggs was 75.0% (18/24), which was higher than in both free-range and organic eggs. On the other hand, 53.2% (25/47) of E. coli carrying virulence genes had MDR, distributed across the production systems as follows: Cage eggs, 76.9% (10/13); free-range eggs, 63.6% (7/11); and organic eggs, 34.8% (8/23). Escherichia coli was detected in eggshell samples from all three egg production systems. The high level of virulence genes, AMR, and integrons indicated the possibility of dissemination of AMR among pathogenic and commensal E. coli through eggshells. These findings could be a major concern to farmers, food handlers, and consumers, especially regarding raw egg consumption.

Antimicrobial resistance in fish pathogens and alternative risk mitigation strategies

AbstractThe discovery of antimicrobial agents, particularly antibiotics, is one of the most important milestones in the history of therapeutics. Since their discovery, antibiotics have been widely used in human medicine, veterinary, agriculture and aquaculture sectors. Many of the antibiotics used in human and veterinary medicine are also being used in the aquaculture sector either for therapy or as prophylactic agents. However, there is increasing awareness and concern for the indiscriminate use of antibiotics and the consequent emergence of antimicrobial resistance in the aquaculture settings. An aquatic environment, especially if it is eutrophic, provides a suitable niche for many bacterial pathogens to survive and multiply. Although there are limited reports of large‐scale outbreaks in the aquaculture sector directly caused by antibiotic resistant fish pathogens, the presence of transferable plasmids, transposons and integrons in fish pathogens such as Aeromonas spp., Edwardsiella spp. and Vibrio spp. is a cause of concern. Thus, the need to study the resistance determinants found in these transmissible elements to different classes of antibiotics carried by fish pathogens and, their dissemination is highly relevant.

Characterization of class 1, 2, 3 integrons, ESBL genes and antibiotic susceptibility of Salmonella serotypes from broiler and cattles in Turkey.

Antimicrobial resistance in Salmonella has been associated with the presence of integrons and many other resistance mechanisms contributing to the spread of antimicrobial-resistant genes within and between livestock and human populations. In this study, the presence of Salmonella serovars from broiler and cattle samples and their antimicrobial resistance, integrons, tet resistance, ESBL and resistance genes carriage were investigated. Total of 209 litter (broiler farms) and fecal samples (cattle farms) were examined by bacteriological procedures, susceptibilities against 18 antimicrobials and genes carriages were detected by singleplex and multiplex PCR. A total of 46/209 (22 %) Salmonella strains were isolated. Six different Salmonella serotypes from 46 Salmonella isolates were identified and the most common serotype was S. Infantis 38 (82.6%) from broiler litter; followed by S. Kitenge 3 (6.5 %) from fecal sample. The highest occurrence of resistance observed for penicilline (46/46, %100), lincomycin (43/46, 93.5%) and 42 isolates (43/46, 93.5%) exhibited MDR. The overall occurrence of class 1, 2 and 3 integrons carrying Salmonella in tested samples were 63.04% (29/46), 43.5% (20/46) and 84.8% (39/46) respectively. Out of the 27 isolates produced an ESBL, mostly CTX and TEM. On 46 Salmonella isolates, in 16 (34.8%) Tcr' genes were determined. Genotypic and phenotipic detection of ESBL genes found within integrons from Salmonella isolates from different sources (broiler and cattle) can provide powerful information about health and economic risk associated with transferable multidrug resistance.

The Prevalence of Integron Classes Genes Among A. Baumannii Isolates

Acinetobacter baumannii has been recently classified as a major threat to public health because it has resistant to almost all antibiotics and there are many reasons that are responsible for conferring this feature to A. baumannii. One of these reasons is integrons so in this study we show the role of the integrons in providing resistance to some antibiotics. A number of 60 isolates were collected from different clinical sources of patients who were admitted to Baghdad hospitals and all isolates were diagnosed using biochemical tests and confirmed using Chrom-ager culture media, and Vitek 2 compact system. The antibiotic susceptibility test was determined during this study using Kirby-Bauer method and the results of susceptibility demonstrate that these bacteria are responsible for providing resistance to Amikacin, Trimethoprim, Piperacillin, Cefepime, Tetracycline, Ampicillin-sulbactam, Imipenem, and levofloxacin. All isolates show high resistance to trimethoprim and low resistance to tetracycline. The presence of integrons in A. baumannii was detected using conventional polymerase chain reactions. The results showed integron class I was found in all 60 isolates with a percentage (100%) while integron class II was found only in 7 isolates with a percentage (11.6%) and the results of detection showed integron class III are not found in the examined isolates. This study conclude that all A. baumnnii isolates had the strongest resistance to various antibiotics, and the class 1 integron appeared to be the most dominant class among class II and III .