Classes Of Integrons Research Articles

High prevalence of CTX-M-15 producing Shigella spp. isolated from patients with gastroenteritis in Northeast Iran.

Shigellosis, a diarrheal disease caused by Shigella species, is a significant public health concern, particularly in developing countries with inadequate sanitation systems. This study aimed to investigate the patterns of antibiotic resistance, ESBL and AmpC genes, integrons, and enterotoxin genes in Shigella species isolated from patients with gastroenteritis in Northeast Iran. This cross-sectional study was conducted between January 2017 and December 2019 at a tertiary care hospital in Northeast Iran. Atotal of 110 Shigella isolates were collected from stool samples of patients with gastroenteritis. The isolates were identified using conventional biochemical tests and confirmed by PCR. The highest resistance rates were detected for ampicillin (88.2%) and cotrimoxazole (84.5%). Altogether 64.5% of isolates exhibited multidrug resistance however, ESBL and AmpC phenotypes were detected in 34.54% and 1.81% of isolates, respectively. Interestingly, blaCTX-M-15 and blaTEM were detected in all ESBL-positive isolates but integron class 1, 2, and 3 were identified in 97.3%, 76.4%, and 59.1% of isolates, respectively. The sen gene was present in 72.7% of the isolates. In this study CTX-M-15 production was detected in 31 strains of Shigella sonnei and in 7 strains of Shigella flexneri. The high prevalence of multidrug-resistant Shigella isolates is concerning and shows the need for continuous monitoring and rational use of antibiotics.

Highly resistant Salmonella Heidelberg circulating in broiler farms in southern Brazil.

Salmonella Heidelberg, a serotype commonly found in Southern Brazil, is characterized by its high resistance and persistence in the poultry production. This study aimed to characterize the antimicrobial resistance of S. Heidelberg strains. In total, 100 strains isolated from poultry between 2020 and 2022 were evaluated. Phenotypic analyses were performed to determine the susceptibility of 16 antimicrobial agents and detect extended-spectrum beta-lactamase (ESBL)-producing strains. Molecular analyses were performed to detect 11 antimicrobial resistance genes (using polymerase chain reaction [PCR]) and integron class 1 genes (using real-time PCR). A total of 98% of isolates was classified as multidrug-resistant. All isolates were resistant to penicillin and lincomycin. High resistance rates (> 85%) were observed for tetracycline, doxycycline, cephalexin, amoxicillin, and ceftiofur. A significant increase (p < 0.05) in antimicrobial resistance is observed for amoxicillin, cephalexin, and ceftiofur between 2020 and 2022. No significant differences (p > 0.05) were observed in antimicrobial resistance with respect to the region of isolation, season, or company. In total, 25% of isolates were ESBL producers. Integron class 1 gene was detected in only one strain, whereas sul2 was detected in 99%, tet(A) in 66%, blaTEM in 37%, strB in 17%, cmlA in 15%, and tet(B) in 11% of the strains. Other genes were not detected or were detected in < 2% of the strains. The results showed a high overall resistance, which increased over the evaluated period. The high proportions of ESBL-producing and antimicrobial resistant strains represent a risk for highly-resistant S. Heidelberg dissemination across broiler flocks.

Heterogeneity and Genomic Plasticity of Acinetobacter baumannii and Acinetobacter nosocomialis Isolates Recovered from Clinical Samples in India.

Acinetobacter baumannii and Acinetobacter nosocomialis are the imperious pathogens in the intensive care units. We aimed to explore the genomic features of these pathogens to understand the factors influencing their plasticity. Using next-generation sequencing, two carbapenem-resistant A. baumannii (AbaBS-3, AbaETR-4) isolates and a pan-susceptible A. nosocomialis (AbaAS-5) isolate were characterised. All genomes exhibited 94% similarity with a degree of heterogeneity. AbaBS-3 and AbaETR-4 harboured antibiotic resistance gene (ARG) repertoire to most antibiotic classes. Carbapenem resistance was due to blaOXA-23 and blaOXA-66 besides the antibiotic efflux pumps. Diverse mobile genetic elements (MGE), insertion sequences (IS), prophages and virulence determinants with a plethora of stress response genes were identified in all three genomes. Class-1 integron in AbaETR-4, encoded genes that confer resistance to aminoglycosides, phenicol, sulfonamides and disinfectants. Substitutions in LpxACD and PmrCAB of AbaETR-4 confirmed the colistin resistance in vitro. Novel mutations in piuA, responsible for transporting cefiderocol, were found in AbaBS-3 and AbaETR-4. Plasmids carrying toxin-antitoxin systems, ARGs and ISs were present in these genomes. All three genomes harboured diverse protein secretion systems, virulence determinants related to immune evasion, adherence, biofilm formation and iron acquisition systems. AbaAS-5 exclusively harboured serine protease pkf, and CpaA substrate of type-II secretion system but lacked the acinetobactin-iron acquisition system. Our work delivers a holistic genome characterization of A. baumannii, coupled with a trailblazing attempt to study A. nosocomialis from India. The presence of ARGs and potential virulence factors interspersed with MGE is a cause for concern, depicting the dynamic adaptability mediated by genetic recombination.

Presence and antimicrobial susceptibility profile of Salmonella spp. isolated from fish farms

Salmonella spp. are important foodborne pathogens often associated with infectious outbreaks caused by consuming contaminated food. Although these microorganisms are widely distributed in several animal production chains, there are few records of their occurrence in aquaculture. This study aimed to evaluate the presence and antimicrobial resistance of Salmonella spp. isolated from fish farms. Samples were collected from three fish farms, covering water, fish, and epilithic biofilm. Salmonella isolates were identified by PCR, and serotyping was performed using the slide agglutination method, according to the Kaufman-White system. Susceptibility to antimicrobial agents was assessed using the Kirby and Bauer disk diffusion method. The presence of class 1 and 2 integrons was determined by PCR. Ninety samples were examined, of which 13 (14.44%) were positive for S. enterica, of which 5 strains were isolated from lagoon water, 3 from fish, and 5 from epilithic biofilm. Among the samples, the serotypes S. Minnesota, S. Panamá, and S. Anatum were identified. Antimicrobial resistance rates were highest for sulfonamides (92.30%), trimethoprim (84.61%), tetracycline (46.15%), and streptomycin (46.15%). Multiple antibiotic resistance was confirmed in 84.61% of the isolates, with 100% presenting integron class 1 and 7.69% integron class 2. This study demonstrated a high prevalence of multiresistant bacteria in fish farms, which reinforces public health concerns due to the use of antibiotics and the risk associated with food from farmed freshwater fish. Given these results, the need for new external research into control and prevention strategies for Salmonella spp. is evident. in aquaculture, as well as greater regulation in fish production chains.

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.

High prevalence of multidrug-resistant Pseudomonas aeruginosa carrying integron and exoA, exoS, and exoU genes isolated from burn patients in Ahvaz, southwest Iran: A retrospective study.

Pseudomonas aeruginosa as an opportunistic pathogen produces several virulence factors. This study evaluated the relative frequency of exoenzymes (exo) A, U and S genes and integron classes (I, II, and III) among multi-drug-resistant clinical P. aeruginosa isolates from burn patients in Ahvaz, southwest of Iran. In this cross-sectional study P. aeruginosa isolates were recovered from 355 wound samples. The antimicrobial susceptibility test was done by disk agar diffusion method on Muller-Hinton agar according to the Clinical and Laboratory Standards Institute. MDR isolates were defined if they showed simultaneous resistance to 3 antibiotics. Extensively drug-resistant was defined as nonsusceptibility to at least one agent in all but two or fewer antimicrobial categories. The presence of class I, II, and III integrons and virulence genes was determined using a PCR assay on extracted DNA. Overall, 145 clinical P. aeruginosa isolates were confirmed with biochemical and PCR tests. Overall, 35% (52/145) of the isolates were taken from males and 64% (93/145) from female hospitalized burn patients. The highest resistance rates of P. aeruginosa isolates to antibiotics were related to piperacillin 59% (n = 86/145) and piperacillin-tazobactam 57% (n = 83/145). A total of 100% of isolates were resistant to at least one antibiotic. MDR and XDR P. aeruginosa had a frequency of 60% and 29%, respectively. The prevalence of integron classes I, II, and III in P. aeruginosa was 60%, 7.58%, and 3.44%, respectively. IntI was more common in MDR and XDR P. aeruginosa isolates. In addition, 70(48%) of P. aeruginosa isolates did not harbor integron genes. Besides, exoA, exoS, and exoU in P. aeruginosa had a frequency of 55%, 55%, and 56%, respectively. It was found that P. aeruginosa as a potent pathogen with strong virulence factors and high antibiotic resistance in the health community can cause refractory diseases in burn patients.

Molecular basis of the persistence of chloramphenicol resistance among Escherichia coli and Salmonella spp. from pigs, pork and humans in Thailand.

This study aimed to investigate the potential mechanisms associated with the persistence of chloramphenicol (CHP) resistance in Escherichia coli and Salmonella enterica isolated from pigs, pork, and humans in Thailand. The CHP-resistant E. coli (n = 106) and Salmonella (n = 57) isolates were tested for their CHP susceptibility in the presence and absence of phenylalanine arginine β-naphthylamide (PAβN). The potential co-selection of CHP resistance was investigated through conjugation experiments. Whole genome sequencing (WGS) was performed to analyze the E. coli (E329, E333, and E290) and Salmonella (SA448, SA461, and SA515) isolates with high CHP MIC (32-256 μg/mL) and predominant plasmid replicon types. The presence of PAβN significantly reduced the CHP MICs (≥4-fold) in most E. coli (67.9%) and Salmonella (64.9%). Ampicillin, tetracycline, and streptomycin co-selected for CHP-resistant Salmonella and E. coli-transconjugants carrying cmlA. IncF plasmids were mostly detected in cmlA carrying Salmonella (IncFIIAs) and E. coli (IncFIB and IncF) transconjugants. The WGS analysis revealed that class1 integrons with cmlA1 gene cassette flanked by IS26 and TnAs1 were located on IncX1 plasmid, IncFIA(HI1)/HI1B plasmids and IncFII/FIB plasmids. IncFIA(HI1)/HI1B/Q1in SA448 contained catA flanked by IS1B and TnAs3. In conclusion, cross resistance through proton motive force-dependent mechanisms and co-selection by other antimicrobial agents involved the persistence of CHP-resistance in E. coli in this collection. Dissemination of CHP-resistance genes was potentially facilitated by mobilization via mobile genetic elements.

Molecular detection of Class 1, 2, and 3 integrons in hypervirulent and classic Klebsiella pneumoniae isolates: A cross-sectional study.

The "hypervirulent" variant of Klebsiella pneumoniae (hvKp) is an emerging pathogen that cause life-threatening infection. The present study was conducted to identify the prevalence of hvKp and to investigate the presence class 1, 2, and 3 integrons in these isolates. A cross-sectional study was conducted at three teaching hospitals, Ahvaz, South-west of Iran, from January 1, 2019 to December 31, 2020. Samples were collected from inpatients and included only the first samples collected from each patient. K. pneumoniae strains were isolated from different specimens using biochemical test and confirmed by targeting 16S-23S rDNA internal transcribed spacer. HvKp isolates were recovered using string test and were further characterized by detection virulence-associated genes (rmpA, iucA, and magA). Antibiotic susceptibility patterns of isolates were determined using the disc diffusion method. Isolates were screened for presence the integron genes (intI, intII, and intIII) and repetitive element sequence-based polymerase chain reaction (PCR) performed to determine strain relatedness. SPSS version 22 was used for the data analysis. Seventy-one (77%) of isolates showed multidrug-resistant (MDR) phenotype. HvKP accounted for 14% (13/92) of cKp isolated from blood (46%) and urinary tract infection (38%), and the great majority of them (61.5%; 8/13) exhibited MDR phenotype. Using the PCR assay, 29 of 92 isolates (31.5%) were found to have positive results for the presence of IntI. Three of the IntI-positive strains were hvKP. Class 2 integron was present in 8/92 cKp isolates. Integron Class 2 was found to coexist with Class 1 integron in 3/8 isolates. All integron-positive isolates (IntI and/or IntII) were resistant to at least three different classes of antibiotics and showed MDR phenotype. No Class 3 integrons were detected among the isolates. The results of our study revealed that considering the role of integrons in facilitating the acquisition and dissemination of resistance genes among bacteria, monitoring the emergence of hvKp, emphasizing on the mechanism of antimicrobial resistance, can prevent from the spread of carbapenemase-producing hvKp strains.

Occurrence of Antimicrobial-Resistant Bacteria in Intestinal Contents of Wild Marine Fish in Chile.

Antimicrobial-resistant bacteria (ARB) from the intestinal contents of wild fish may have a relevant ecological significance and could be used as indicators of antimicrobial-resistance dissemination in natural bacterial populations in water bodies impacted by urban contamination. Thus, the occurrence of ARB in the intestinal contents of pelagic and demersal wild fishes captured in anthropogenic-impacted Coquimbo Bay in Chile was studied. Culturable counts of total and antimicrobial-resistant bacteria were determined by a spread plate method using Trypticase soy agar and R2A media, both alone and supplemented with the antimicrobials amoxicillin, streptomycin, florfenicol, oxytetracycline and ciprofloxacin, respectively. Heterotrophic plate counts of pelagic and demersal fishes ranged from 1.72 × 106 CFU g-1 to 3.62 × 109 CFU g-1, showing variable proportions of antimicrobial resistance. Representative antimicrobial-resistant isolates were identified by 16S rRNA gene sequencing, and isolates (74) from pelagic fishes mainly belonged to Pseudomonas (50.0%) and Shewanella (17.6%) genera, whereas isolates (68) from demersal fishes mainly belonged to Vibrio (33.8%) and Pseudomonas (26.5%) genera. Antimicrobial-resistant isolates were tested for susceptibility to 12 antimicrobials by an agar disk diffusion method, showing highest resistance to streptomycin (85.2%) and amoxicillin (64.8%), and lowest resistance to oxytetracycline (23.2%) and ciprofloxacin (0.7%). Only furazolidone and trimethoprim/sulfamethoxazole were statistically different (p < 0.05) in comparisons between isolates from pelagic and demersal wild fishes. Furthermore, an important number of these isolates carried plasmids (53.5%) and produced Extended-Spectrum-β-lactamases (ESBL) (16.9%), whereas the detection of Metallo-β-Lactamases and class 1-integron was rare. This study provides evidence that wild fish are important reservoirs and spreading-vehicles of ARB, carrying plasmids and producing ESBLs in Chilean marine environments.

Molecular Analysis of the Antiseptic Resistance Genes among Multidrug-Resistant Pseudomonas aeruginosa Isolated from Burn Patients

Abstract Background: Pseudomonas aeruginosa is known to be susceptible to a variety of antibiotics and disinfectants, and this resistance has become a major problem, particularly among hospitalized patients. Objectives: The present study aims to determine the association between class 1 integrons (intI1) and genes responsible for antiseptic resistance (fabV, qacΔE1, and qacE) among multidrug-resistant (MDR) P. aeruginosa from burn patients. Materials and Methods: Sixty-four isolates from burns were identified using both standard approaches and the VITEK 2 system. Disc diffusion antimicrobial susceptibility testing was performed. Polymerase chain reaction (PCR) was utilized to identify class 1 integrons and antiseptic resistance genes using specific primers for intI1, fabV, qacE1, and qacE. Results: 64 MDR P. aeruginosa isolates were obtained from burn patients during the research period. The antibiotic susceptibility of all 64 P. aeruginosa isolates was examined. MDR resistance to at least three antibiotic classes were found in all of the isolates. The PCR results revealed that 100% of the isolates tested positive for the class 1 integron gene. According to the current findings, all isolates possessed the qacΔE1 and fabV genes. While the qacE results were being processed, 87.50% of the isolates tested positive. There was no correlation between the presence of antiseptic resistance genes and antibiotic resistance (P ˃ 0.05). Conclusion: our data suggest that P. aeruginosa isolates have profound antibiotic resistance and an antiseptic resistance gene. The integron was mostly found in all isolates, indicating that the Antiseptic resistance gene corresponds to the integron class 1.

Detection of resistance integrons among biofilm and non-biofilm producing clinical isolates of Pseudomonas aeruginosa.

Integrons are genetic systems that may confer antibiotic resistance to Pseudomonas aeruginosa. Biofilm formation can facilitate gene exchange and can accelerate the development of antibiotic resistance. The aim of this work was to assess the distribution of resistance integrons including class 1, 2 and 3 among biofilm- and non-biofilm producing clinical strains of P. aeruginosa. We also aimed to investigate the relationship between the existence of these integrons and the isolates' resistance patterns. Specimens were obtained from patients showing evidence of infection. P. aeruginosa isolates were identified using conventional techniques, while disk diffusion test was used to detect their antimicrobial susceptibilities. Biofilm formation was detected by the tissue culture plate technique, while classes of integrons were detected by polymerase chain reaction. Out of 106 P. aeruginosa isolates, 55.7% were class 1 integron-positive while 19.8% were class 2 integron-positive. However, class 3 integrons were not detected. Significant associations were found between class 1 integrons and resistance toward amikacin, gentamicin, cefepime, ceftazidime and ciprofloxacin. Class 2 integrons were associated with amikacin, ceftazidime and cefepime resistance. Of pseudomonal isolates, 61.3% were biofilm producing. Biofilm production was associated significantly with the existence of class 1 integrons (p<0.001) and class 2 integrons (p=0.039). About two thirds of isolated strains harbored resistance integrons, which emphasized their significance in our locality. The frequencies of class 1 and 2 integrons were significantly higher among biofilm forming isolates. Ongoing surveillance and infection control strategies are necessary to limit spread of integrons.

Antibiotic resistance profile in sediments and bacterial isolates from a human-impacted mangrove from Bahía Magdalena, Mexico

Abstract Antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) in the environment are considered emerging contaminants. One of the ecosystems that can harbor resistant bacteria and genes is mangroves. This report aims to assess ARB and ARG's presence at two mangrove locations in Bahia Magdalena, Mexico. Bacterial isolates were selected based on their phenotypic profiles of antibiotic resistance. DNA from mangrove sediments and bacterial isolates was tested for int1 and antibiotic resistance genes by final point PCR. From 90 ARB isolates, the phenotypic profile showed resistance to ciprofloxacin (90%), cefotaxime (85.7%), and ampicillin (78.6%), while the beta-lactamase gene (blaCTX-M) was present in 72.9% of the isolates. Antibiotic resistance genes identified in sediments were found even at 30–50 cm depth, but the integron Class gen (int1) was found mainly in shallow samples. Principal component analysis showed a close relationship between the integron gene, vancomycin, and sulfonamides resistance genes. No correlation was found between the phenotypic and genotypic profiles of the bacterial isolates. Also, no differences were observed between the two mangrove ecosystems studied. The impact of anthropogenic activities was equally significant on both sites. The role of mangrove ecosystems in the dispersion of antibiotic resistance needs to be further explored.

Occurrence and fate of CECs (OMPs, ARGs and pathogens) during decentralised treatment of black water and grey water

Decentralised wastewater treatment is becoming a suitable strategy to reduce cost and environmental impact. In this research, the performance of two technologies treating black water (BW) and grey water (GW) fractions of urban sewage is carried out in a decentralised treatment of the wastewater produced in three office buildings. An Anaerobic Membrane Bioreactor (AnMBR) treating BW and a Hybrid preanoxic Membrane Bioreactor (H-MBR) containing small plastic carrier elements, treating GW were operated at pilot scale. Their potential on reducing the release of contaminants of emerging concern (CECs) such as Organic Micropollutants (OMPs), Antibiotic Resistance Genes (ARGs) and pathogens was studied. After 226 d of operation, a stable operation was achieved in both systems: the AnMBR removed 92.4 ± 2.5 % of influent COD, and H-MBR removed 89.7 ± 3.5 %. Regarding OMPs, the profile of compounds differed between BW and GW, being BW the matrix with more compounds detected at higher concentrations (up to μg L−1). For example, in the case of ibuprofen the concentrations in BW were 23.63 ± 3.97 μg L−1, 3 orders of magnitude higher than those detected in GW. The most abundant ARGs were sulfonamide resistant genes (sul1) and integron class 1 (intl1) in both BW and GW. Pathogenic bacteria counts were reduced between 1 and 3 log units in the AnMBR. Bacterial loads in GW were much lower than in BW, being no bacterial re-growth observed for the GW effluents after treatment in the H-MBR. None of the selected enteric viruses was detected in GW treatment line.

Examining the Frequency of Carbapenem Resistance Genes and Its Relationship with Different Classes of Integrons Including Classes I and II in Pseudomonas aeruginosa Isolates of Burn Patients

Background: Pseudomonas aeruginosa is one of the most important opportunistic pathogens causing hospital infections. Objectives: This study aimed to investigate the abundance of integrons and the pattern of resistance to carbapenems (metallo-β-lactamases including Spm, Imp, and Vim) and its relationship with the presence of integrons classes I and II in P. aeruginosa isolates. Methods: This study was conducted on 73 samples of P. aeruginosa isolated from burn wounds of patients admitted to the burn center of Velayat Hospital, Rasht, Iran. To confirm the phenotype of P. aeruginosa, Gram staining and diagnostic biochemical tests, including oxidation-fermentation (OF), pigment production, citrate utilization, catalase activity, oxidase test, and growth at 42°C, were used. After identification and confirmation, molecular diagnosis was conducted to identify strains producing genes classes I and II using the polymerase chain reaction (PCR) method. Results: In this research, the frequency of carbapenem resistance genes in clinical isolates of P. aeruginosa was found to be zero, 13.7%, and 21.9% for blaSpm, blaImp, and blaVim genes, respectively. Integrons of classes I and II were present in 53.4% of isolates of class I and 17.8% of isolates of class II. Also, 4.1% of the total integrin-positive isolates had both integron classes. Conclusions: There was a statistically significant relationship between class I integron and the blaImp gene. Importantly, the mechanisms of other integrons play a role in the development of resistance and the presence of these genes involved in this project.

Clonal spread of trimethoprim-sulfamethoxazole-resistant Stenotrophomonas maltophilia isolates in a tertiary hospital.

The aims of this study were to: (i) determine antibiotic susceptibility of clinical Stenotrophomonas maltophilia isolates, (ii) investigate the presence of different classes of integrons and sul genes responsible for sulphonamide resistance, (iii) assess the molecular epidemiology of the isolates by determining their clonal relatedness, and (iv) investigate the potential sources of infection by collecting environmental samples when necessary. 99 S. maltophilia isolates from clinical specimens of hospitalized patients were screened by PCR for sul1, sul2, sul3 genes, and integron-associated integrase genes: intI1, intI2, and intI3. PFGE was used to determine the clonal relatedness of the isolates. Susceptibility rates for trimethoprim-sulfamethoxazole, levofloxacin, and ceftazidime were 90.9%, 91.9%, and 53.5% respectively. All trimethoprim-sulfamethoxazole-resistant isolates were positive for intI1 and sul1. PFGE analysis revealed that 24 of the isolates were clonally related, clustering in seven different clones. Five of the nine trimethoprim-sulfamethoxazole-resistant isolates were clonally related. The first isolate in this clone was from a wound sample of a patient in the infectious diseases clinic, and the other four were isolated from the bronchoalveolar lavage samples of patients in the thoracic surgery unit. The patient with the first isolate neither underwent bronchoscopy nor stayed in the thoracic surgery unit. Although clustering was observed in bronchoalveolar lavage samples, no S. maltophilia growth was detected in environmental samples. The findings demonstrated that the sul1 gene carried by class 1 integrons plays an important role in trimethoprim-sulfamethoxazole resistance in S. maltophilia isolates. PFGE analysis revealed a high degree of genetic diversity. However, detection of clonally related isolates suggests the acquisition from a common source and/or cross-transmission of this microorganism between the patients.

Dissemination of Integron Class 1 among XDR isolates of P. aeruginosa in Najaf City

Background: Integrons are gene capture systems observed in chromosomes, plasmids, and transposons, where identified and capture multiple gene cassettes. Integerons are consists of 3 elements: the initial is integrase gene (int1) encoding integrase enzyme (int1), which is essential to insertion or deletion of specific site. The second element is attI as integron-connected recombination site. The 3rd element is promoter (Pc), which is required in the expression of cassette-connected genes. &#x0D; Aim of the Study: This thesis designed to examine the occurrence of integron class one genes among XDR isolates of P. aeruginosa. &#x0D; Methods: An overall of 79 specimens were isolated from patients during the period of study and the specimens were carried to the laboratory. By monoplex PCR assay, the 19 XDR isolates of P. aeruginosa were investigated for the presence of integrons class one using intI1primer. &#x0D; Results: This result found that 8 isolates are isolated from burns, 7 isolates are from urine, 4 isolates are from wounds. The PCR results show that 17 (89.5%) of the isolates harbored integrase (intI1) gene, while two isolate (10.5%) was negative for intI1 gene. Conclusions: Present result showed elevated occurrence of integrons class one among XDR isolates of P.aeruginosa.

Prevalence, virulence characteristics, and antimicrobial resistance of Vibrio parahaemolyticus isolates from raw seafood in a province in Northern Thailand.

Vibrio parahaemolyticus (V. parahaemolyticus) is commonly found in seawater and seafood products, but evidence is limited of its presence in seafood marketed in locations very distant from coastal sources. This study determined the prevalence and characterization of V. parahaemolyticus in seafood from markets in landlocked Phayao province, Northern Thailand. Among 120 samples, 26 (21.7%) were positive for V. parahaemolyticus, being highest in shrimp (43.3%), followed by shellfish (36.7%), and squid (6.7%), but was not found in fish. V. parahaemolyticus comprised 33 isolates that were non-pathogenic and non-pandemic. Almost all isolates from shrimp and shellfish samples were positive for T3SS1. Only five isolates (15.2%) showed two antimicrobial resistance patterns, namely, kanamycin-streptomycin (1) carrying sul2 and ampicillin-kanamycin-streptomycin (4) that carried tetA (2), tetA-sul2 (1), as well as one negative. Antimicrobial susceptible V. parahaemolyticus isolates possessing tetA (67.9%) and sul2 (3.5%) were also found. Six isolates positive for integron class 1 and/or class 2 were detected in 4 antimicrobial susceptible and 2 resistant isolates. While pathogenic V. parahaemolyticus was not detected, contamination of antimicrobial resistance V. parahaemolyticus in seafood in locations distant from coastal areas requires ongoing monitoring to improve food safety in the seafood supply chain.

A Class 4-like Chromosomal Integron Found in Aeromonas sp. Genomospecies paramedia Isolated from Human Feces.

Integrons are genetic elements that store, express and exchange gene cassettes. These elements are characterized by containing a gene that codes for an integrase (intI), a cassette integration site (attI) and a variable region holding the cassettes. Using bioinformatics and molecular biology methods, a functional integron found in Aeromonas sp. 3925, a strain isolated from diarrheal stools, is described. To confirm the integron class, a phylogenetic analysis with amino acid sequences was conducted. The integrase was associated to class 4 integrases; however, it is clearly different from them. Thus, we classified the associated element as a class 4-like integron. We found that the integrase activity is not under the control of the SOS or catabolic repression, since the expression was not increased in the presence of mitomycin or arabinose. The class-4-like integron is located on the chromosome and contains two well-defined gene cassettes: aadA1 that confers resistance to streptomycin and lpt coding for a lipoprotein. It also includes eight Open Reading frames (ORFs) with unknown functions. The strain was characterized through a Multilocus Phylogenetic Analyses (MLPA) of the gyrB, gyrA, rpoD, recA, dnaJ and dnaX genes. The phylogenetic results grouped it into a different clade from the species already reported, making it impossible to assign a species. We resorted to undertaking complete genome sequencing and a phylogenomic analysis. Aeromonas sp. 3925 is related to A. media and A. rivipollensis clusters, but it is clearly different from these species. In silico DNA-DNA hybridization (isDDH) and Average Nucleotide Identity (ANI) analyses suggested that this isolate belongs to the genomospecies paramedia. This paper describes the first class 4-like integron in Aeromonas and contributes to the establishment of genomospecies paramedia.

Correlation of Phylogenetic with Antibiotics Resistance Profiles and Integron Class I in Clinical Isolates of Klebsiella pneumoniae in Baquba City

Correlation of Phylogenetic with Antibiotics Resistance Profiles and Integron Class I in Clinical Isolates of Klebsiella pneumoniae in Baquba City

Using of Integrons as Biomarker to Assess Dissemination and Diversity of Antimicrobial Resistance Genes in Farm Animal Manure

Antimicrobial agents are widely used for treatment of animal and human diseases. Heavy use of antimicrobial agents permits bacteria to develop resistance to these agents specifically when a dose of antibiotic is insufficient or course of treatment is incomplete. Antimicrobial resistance genes (ARGs) are usually associated with mobile genetic elements (MGEs) including Integron therefore; these genes can transmit among bacteria via horizontal transmission. The current study was conducted to assess the possible role of manure in dissemination of antimicrobial resistance. The presence, quantitate, and diversity of resistance genes associated with Integron class 1 have been assessed using conventional and quantitative polymerase chain reaction (PCR) combined with sequencing of gene cassette within Integron and analysis of sequenced data by blast tool. Thirty-eight samples were found a positive for Integron and concentration of Integron in positive sample ranged from from 106-1010 copies/g of manure. High frequencies were detected to genes that encoded to sulphonamide and ammonium compound resistance. These genes were detected in 25% and 23% respectively of the total manure samples. In general, the detected genes in manure functionally belong to five protein families including Efflux pump, DNA repair, heavy metal resistance, membrane protein, and antibiotic resistance. Manure might act as a hotspot from which ARGs emerge and transfer to the environment and then to the animal and human environments.