Haemolysin and Shigella Toxin Production in Multidrug Resistant  Escherichia Coli  Pathotypes from Clinical Specimens

The acquisition and dissemination of virulent traits represent a survival advantage to bacterial pathogens. Drug resistance is on the rise among E. coli strains that cause human infections. Proper selection of antimicrobial treatment depends on the susceptibility test outcomes. A total of 178 bacterial isolates were phenotypically screened for Haemolysin and Shigatoxin production, then to obtain Multidrug Resistant (MDR) E. coli . Twelve isolates were identified and selected based on the ability to grow on Luria-Bertani (LB) agar medium containing 100μg/ml Ampicillin. The isolates, coded as; U01, U02, U03, U04, U08, U10 and U11 were from urine specimens, S05, S06, S07 and S12 from stool, while B09 was from blood. The isolates were screened for multidrug resistant pattern according to Kirby-Bauer disc diffusion method. Genes hlyA and stx1 encoding the virulence factors; Haemolysin A and Shigatoxin1 was PCR amplified and sequenced. All the isolates were resistant to Ampicillin, Cephalothin, Erythromycin, Fusidic acid, Novobiocin and Oxacillin, but sensitive to Colistin sulphate and Imipenem. Nine isolates (75%) are sensitive to Augmentin. All the virulence genes ( hlyA and stx1 ) are present in isolates S07 and U08. The isolates (75%) produced 2 to 4 of each of the genes indicating a strong relationship in determining multidrug resistance. Haemolysin ( hlyA ) was the most common (66.7%) gene in urine, stool and blood isolates. Most of the virulence genes sequence (61.8%) in this study had significant alignment (95 to 100% homology) with E.coli genome in the NCBI database. This study revealed the interplay of drug resistance and virulence at genetic levels, so advocate for further identification of the mechanisms regulating the expression of these traits, to improve the management of bacterial infections.

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Genotypic Detection and Characterization of Adhesins in Clinical Escherichia coli Isolates

Microbiology Research Journal International ◽

10.9734/mrji/2020/v30i830254 ◽

2020 ◽

pp. 84-93

Author(s):

M. Y. Iliyasu ◽

I. Mustapha ◽

H. Yakubu ◽

H. M. Shuaibu ◽

A. F. Umar ◽

...

Keyword(s):

Escherichia Coli ◽

Strong Relationship ◽

Multidrug Resistant ◽

Luria Bertani ◽

Diffusion Method ◽

Gram Negative Bacteria ◽

Virulence Determinants ◽

Gram Negative ◽

Virulence Markers ◽

Significant Alignment

Background of Study: Many virulence determinants contribute to the pathogenicity of Gram negative bacteria, like Escherichia coli, which is the most common cause of many infections worldwide such as urinary tract infection (UTI), profuse diarrhoea and septicaemia. Aim: To determine the genotypic characteristics of adhesin-producing E. coli isolates from clinical specimens. Place and Duration of Study: Conducted at the Infectious diseases hospital Bayara, Bauchi state, Nigeria, between February to March, 2019. Methods: A total of twelve (12) Gram negative bacterial isolates were selected based on the ability to grow on Luria-Bertani (LB) agar medium containing 100 µg/ml ampicillin. The isolates were from urine, stool, and blood specimens. The isolates were screened for multidrug resistant pattern according to Kirby-Bauer disc diffusion method. Adhesion factors, Fimbrial adhesin (fimH) and Invasive plasmid adhesin (ipaH) was genotyped by conventional PCR and sequenced. Results: All the isolates were resistant to Ampicillin, Cephalothin, Erythromycin, Fusidic acid, Novobiocin and Oxacillin, but sensitive to Augmentin, Colistin sulphate and Imipenem. Presence of fimH and ipaH genes were observed in nine isolates that expressed strong relationship with. Multidrug resistance (MDR). The fimH was the most prevalent found in urine, stool and blood isolates. Most of the adhesion genes sequence (61.8%) in this study had significant alignment (95 to 100% homology) with E.coli genome in the NCBI database. Conclusion: This study revealed the role of adhesin as virulence markers in MDR Gram negative bacteria and FimH is one of the commonest gene in MDR E.coli pathotypes.

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Drug Resistance of Pathogens Causing Nosocomial Infection in Orthopedics from 2012 to 2017: A 6-Year Retrospective Study

10.21203/rs.3.rs-103706/v1 ◽

2020 ◽

Author(s):

Xiaowei Yang ◽

Runsheng Guo ◽

Banglin Xie ◽

Qi Lai ◽

Jiaxiang Xu ◽

...

Keyword(s):

Drug Resistance ◽

Retrospective Study ◽

Antimicrobial Resistance ◽

Bacterial Infections ◽

Multidrug Resistant ◽

Dynamic Monitoring ◽

Resistant Bacteria ◽

Clinical Microbiology Laboratory ◽

Valuable Insight ◽

E Coli

Abstract Background: Hospital-acquired infections (HAIs) are an emerging global problem that increases in-hospital mortality, length of stay, and cost. We performed a 6-year retrospective study to provide valuable insight into appropriate antibiotic use in HAI cases. We also aimed to understand how hospitals could reduce pathogen drug resistance in a population that overuses antibiotics.Methods: All data (2012–2017) were obtained from the Hospital Information Warehouse and Clinical Microbiology Laboratory.Results: We isolated 1392 pathogen strains from patients admitted to the orthopedics department during 2012–2017. Escherichia coli (14.7%, 204/1392), Enterobacter cloacae (13.9%, 193/1392), and Staphylococcus aureus (11.3%, 157/1392) were the most common pathogens causing nosocomial infections. The dominant Gram-negative bacterium was E. coli, with high resistance to ampicillin, levofloxacin, cotrimoxazole, gentamicin, and ciprofloxacin, in that order. E. coli was least resistant to amikacin, cefoperazone-sulbactam. The most dominant Gram-positive bacterium was S. aureus, highly resistant to penicillin and ampicillin, but not resistant to fluoroquinolones and cotrimoxazole. Analysis of risk factors related to multidrug-resistant bacteria showed that patients with open fractures were significantly more susceptible to methicillin-resistant S. aureus infections (p < 0.05). Additionally, extended-spectrum β-lactamase-producing E. coli infections occurred significantly more often in patients with degenerative diseases (p < 0.05). Elderly patients tended to be more susceptible to multidrug-resistant bacterial infections, but this outcome was not statistically significant.Conclusions:Antimicrobial resistance is a serious problem in orthopedics. To effectively control antimicrobial resistance among pathogens, we advocate extensive and dynamic monitoring of MDR bacteria, coupled with careful use of antibiotics.

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An Epidemiological Study of Drug Resistance and Resistance Genes in Bovine Escherichia coli Isolates in Heilongjiang Province of China

Acta Scientiae Veterinariae ◽

10.22456/1679-9216.89374 ◽

2018 ◽

Vol 46 (1) ◽

pp. 9

Author(s):

Jia-San Zheng ◽

Ting-Ting Zhu ◽

Yun Liu ◽

Ting Liu ◽

Yan-Qing Li ◽

...

Keyword(s):

Escherichia Coli ◽

Drug Resistance ◽

Resistance Gene ◽

Resistance Genes ◽

Multidrug Resistant ◽

Diffusion Method ◽

Heilongjiang Province ◽

Antibacterial Drugs ◽

Resistance Phenotype ◽

E Coli

Background: To explore the epidemiology of bovine multidrug-resistant Escherichia coli isolates and resistance genes in Heilongjiang province of China. This study examined the prevalence of genes in bovine E. coli isolates, which confer resistance to antibiotics that are commonly used in the clinic, in regions of Baiquan, Shangzhi, and Songbei of Harbin. The purpose of the study was to investigate the epidemiology of the main resistance genes of bovine E. coli isolates in clinical veterinary medicine, and to provide a theoretical basis for preventing the spread of drug-resistant bacteria, as well as for rational drug use.Materials, Methods & Results: The sensitivity of 105 isolates to 22 antibiotics was determined using the KirbyBauer disk diffusion method, and the distribution of 19 kinds of common drug resistance genes was investigated using Polymerase Chain Reaction. The results showed that the resistance rate to nine antibiotics was over 50%, including rifampin (84.76%), ampicillin (73.58%), tetracycline (69.52%), and sulfisoxazole (59.05%). In total, 105 strains of bovine E. coli presented 21 spectra of drug resistance, including eight strains (7.62%, 8/105) that were resistant to one antibiotic and four strains (3.81%, 4/105) that were resistant to 21 antibiotics. The resistance gene detection results showed that the streptomycin-resistance gene strA was found in 73 isolates, accounting for 69.52% of the isolates, followed by the sulfanilamide-resistance genes sul3/sul2 and the aminoglycoside-resistance gene aphA, which accounted for 57.14%, 51.43%, and 50.48%, respectively, of the isolates.Discussion: This study revealed serious drug resistance of bovine E. coli isolates in some areas of Heilongjiang province. Of 105 E. coli isolates, more than 50% were resistant to the following antibacterial drugs: rifampicin, ampicillin, tetracycline, sulfisoxazole, and cephalothin. The isolates were the most sensitive to amikacin, with a sensitivity of 84.76%, followed by sensitivity to ofloxacin, ciprofloxacin, norfloxacin, cefoxitin, and tobramycin. Drug sensitivity tests showed that the drug resistance spectra of the bovine E. coli isolates was different in different regions, indicating that there were multidrug-resistant bovine E. coli isolates in different regions of Heilongjiang province, and that drug resistance differed among different regions. This may be due to prolonged use or overuse of antibiotics in a particular locality. Additionally, because of different management modes of livestock farms, the application of antimicrobial drugs in some farms may have imposed selective pressure on the intestinal flora including E. coli, resulting in the horizontal transmission of drug resistance among the bacteria. The study found that some strains had a resistance phenotype, but no resistance gene, while some had a resistance gene without expressing a resistance phenotype, which is consistent with relevant reports in the literature. This may be related to the same genotype corresponding to different resistance phenotypes, or different levels of gene expression, or different drug metabolic rates. In our study, some strains with certain drug resistance genes were sensitive to the corresponding drug, which may be due to mutations of drug-resistance genes, the loss of a strains resistance phenotype, or the loss of gene function. These issues require further study. This study revealed serious drug resistance of bovine E. coli isolates in some areas of Heilongjiang province. Of 105 E. coli isolates, more than 50% were resistant to the following antibacterial drugs: rifampicin, ampicillin, tetracycline, sulfisoxazole, and cephalothin. The isolates were the most sensitive to amikacin, with a sensitivity of 84.76%, followed by sensitivity to ofloxacin, ciprofloxacin, norfloxacin, cefoxitin, and tobramycin.

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Phenotypic and molecular characterizations of multidrug-resistant diarrheagenic E. coli of calf origin

Animal Diseases ◽

10.1186/s44149-021-00019-3 ◽

2021 ◽

Vol 1 (1) ◽

Author(s):

Shan Yue ◽

Zecai Zhang ◽

Yu Liu ◽

Yulong Zhou ◽

Chenhua Wu ◽

...

Keyword(s):

Beef Cattle ◽

Dairy Cattle ◽

Resistance Genes ◽

Virulence Genes ◽

Interaction Mechanism ◽

Multidrug Resistant ◽

Resistance Rate ◽

Diffusion Method ◽

Disk Diffusion Method ◽

E Coli

AbstractEscherichia coli has become one of the most important causes of calf diarrhea. The aim of this study is to determine the patterns of antimicrobial resistance of E. coli isolates from six cattle farms and to identify prominent resistance genes and virulence genes among the strains isolated from the diarrhea of calves. Antimicrobial susceptibility tests were performed using the disk diffusion method, and PCR was used to detect resistance and virulence genes. The prevalence of multidrug resistant (MDR) E. coli was 77.8% in dairy cattle and 63.6% in beef cattle. There were high resistance rates to penicillin (100%, 100%) and ampicillin (96.3%, 86.4%) in E. coli from dairy cattle and beef cattle. Interestingly, resistance rate to antimicrobials and distribution of resistance genes in E. coli isolated from dairy cattle were higher than those in beef cattle. Further analysis showed that the most prevalent resistance genes were blaTEM and aadA1 in dairy cattle and beef cattle, respectively. Moreover, seven diarrheagenic virulence genes (irp2, fyuA, Stx1, eaeA, F41, K99 and STa) were present in the isolates from dairy cattle, with a prevalence ranging from 3.7% to 22.22%. Six diarrheagenic virulence genes (irp2, fyuA, Stx1, eaeA, hylA and F41) were identified in the isolates from beef cattle, with a prevalence ranging from 2.27% to 63.64%. Our results provide important evidence for better exploring their interaction mechanism. Further studies are also needed to understand the origin and transmission route of E. coli in cattle to reduce its prevalence.

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Isolation of a 29.5 kb Plasmid conferring Multiple Drug Resistance in Pseudomonas aeruginosa

Journal of Bio-Science ◽

10.3329/jbs.v17i0.7113 ◽

1970 ◽

Vol 17 ◽

pp. 95-100

Author(s):

Shahanara Begum ◽

Iftikhar Ahmed ◽

Faisal Alam ◽

M Samsuzzaman ◽

Parvez Hassan ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Drug Resistance ◽

Plasmid Dna ◽

Multiple Drug Resistance ◽

Multidrug Resistant ◽

Diffusion Method ◽

Multiple Drug ◽

Donor Strain ◽

E Coli ◽

Resistant Bacterial Strain

Context: Worldwide emergence of plasmid mediated multi drug resistant bacterial strain is a growing concern, especially in hospital infections caused by Pseudomonas aeruginosa. Relation of plasmid and drug resistance in clinical isolates of P. aeruginosa by curing and transformation experiments is scanty.Objectives: To isolate, purify and characterize plasmid DNA harbored in a selected Pseudomonas aeruginosa strain encoding multiple drug resistance and to perform transformation of the isolated plasmid into a sensitive strain of Escherichia coli LE 392 to judge transformation potential of the donor P. aeruginosa strain. Materials and Methods: Plasmid DNA was isolated from a multidrug-resistant (MDR) strain of P. aeruginosa obtained from swab of a hospitalized burn patient by mini-scale method. DNA was purified, quantitatively estimated and electrophoresed on 0.8% agarose gel. Transformation was done as per Cohen and co-workers using plasmid DNA isolated from MDR P. aeruginosa strain as the donor and the E. coli LE 392 strain. The presence of plasmid in transformants checked through electrophoresis and the transformants was also tested for each drug resistance already recorded for the donor strain by disc diffusion method and again confirmed by spreading its culture on the selected antibiotic plate of different concentrations. Results: A single plasmid of nearly 29.5 kb mass was isolated from MDR P. aeruginosa strain from clinical swab. This plasmid was transferred into sensitive and plasmid lacking recipient E. coli LE 392. Subsequent experiments on the transformed strain revealed that it acquired MDR and harbored a 29.5 kb plasmid which resembled to that of the donor strain proving that it encodes transferable MDR.Conclusion: The MDR P. aeruginosa strain contained a transferable plasmid conferring resistance to ampicillin, chloramphenicol, cotrimoxazole, tetracycline and ciprofloxacin. Key words: Pseudomonas aeruginosa; Multidrug–resistance; plasmid isolation; transformation. DOI: 10.3329/jbs.v17i0.7113J. bio-sci. 17: 95-100, 2009

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The Relationship between Antibiotic Susceptibility and pH in the Case of Uropathogenic Bacteria

Antibiotics ◽

10.3390/antibiotics10121431 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1431

Author(s):

Annamária Kincses ◽

Bálint Rácz ◽

Zain Baaity ◽

Orsolya Vásárhelyi ◽

Erzsébet Kristóf ◽

...

Keyword(s):

Antibiotic Resistance ◽

Bacterial Infections ◽

Enteric Bacteria ◽

Multidrug Resistant ◽

Diffusion Method ◽

Disk Diffusion Method ◽

E Coli ◽

Microdilution Method ◽

Tract Infections ◽

Uropathogenic Bacteria

Urinary tract infections (UTIs) are common bacterial infections caused mainly by enteric bacteria. Numerous virulence factors assist bacteria in the colonization of the bladder. Bacterial efflux pumps also contribute to bacterial communication and to biofilm formation. In this study, the phenotypic and genetic antibiotic resistance of clinical UTI pathogens such as Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis were determined by disk diffusion method and polymerase chain reaction (PCR). Following this, different classes of antibiotics were evaluated for their antibacterial activity at pH 5, 6, 7 and 8 by a microdilution method. Gentamicin (GEN) was the most potent antibacterial agent against E. coli strains. The effect of GEN on the relative expression of marR and sdiA genes was evaluated by quantitative PCR. The slightly acidic pH (pH 6) and GEN treatment induced the upregulation of marR antibiotic resistance and sdiA QS activator genes in both E. coli strains. Consequently, bacteria had become more susceptible to GEN. It can be concluded that antibiotic activity is pH dependent and so the artificial manipulation of urinary pH can contribute to a more effective therapy of multidrug resistant bacterial infections.

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Presence of β-Lactamase-producing Enterobacterales and Salmonella Isolates in Marine Mammals

International Journal of Molecular Sciences ◽

10.3390/ijms22115905 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5905

Author(s):

Olivia M. Grünzweil ◽

Lauren Palmer ◽

Adriana Cabal ◽

Michael P. Szostak ◽

Werner Ruppitsch ◽

...

Keyword(s):

Escherichia Coli ◽

Marine Mammals ◽

Virulence Genes ◽

Multidrug Resistant ◽

Healthcare Sector ◽

Whole Genome ◽

E Coli ◽

High Prevalence ◽

Lactamase Gene ◽

Sequence Types

Marine mammals have been described as sentinels of the health of marine ecosystems. Therefore, the aim of this study was to investigate (i) the presence of extended-spectrum β-lactamase (ESBL)- and AmpC-producing Enterobacterales, which comprise several bacterial families important to the healthcare sector, as well as (ii) the presence of Salmonella in these coastal animals. The antimicrobial resistance pheno- and genotypes, as well as biocide susceptibility of Enterobacterales isolated from stranded marine mammals, were determined prior to their rehabilitation. All E. coli isolates (n = 27) were screened for virulence genes via DNA-based microarray, and twelve selected E. coli isolates were analyzed by whole-genome sequencing. Seventy-one percent of the Enterobacterales isolates exhibited a multidrug-resistant (MDR) pheno- and genotype. The gene blaCMY (n = 51) was the predominant β-lactamase gene. In addition, blaTEM-1 (n = 38), blaSHV-33 (n = 8), blaCTX-M-15 (n = 7), blaOXA-1 (n = 7), blaSHV-11 (n = 3), and blaDHA-1 (n = 2) were detected. The most prevalent non-β-lactamase genes were sul2 (n = 38), strA (n = 34), strB (n = 34), and tet(A) (n = 34). Escherichia coli isolates belonging to the pandemic sequence types (STs) ST38, ST167, and ST648 were identified. Among Salmonella isolates (n = 18), S. Havana was the most prevalent serotype. The present study revealed a high prevalence of MDR bacteria and the presence of pandemic high-risk clones, both of which are indicators of anthropogenic antimicrobial pollution, in marine mammals.

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Antibiotic Resistance of Uropathogens Isolated from Patients Hospitalized in District Hospital in Central Poland in 2020

Antibiotics ◽

10.3390/antibiotics10040447 ◽

2021 ◽

Vol 10 (4) ◽

pp. 447

Author(s):

Barbara Kot ◽

Agata Grużewska ◽

Piotr Szweda ◽

Jolanta Wicha ◽

Urszula Parulska

Keyword(s):

Antibiotic Resistance ◽

Multidrug Resistant ◽

Diffusion Method ◽

Disk Diffusion Method ◽

Beta Lactamases ◽

E Coli ◽

Central Poland ◽

Resistance Patterns ◽

Extended Spectrum Beta Lactamases ◽

Tract Infections

The aim of this study was to determine antibiotic resistance patterns and the prevalence of uropathogenes causing urinary tract infections (UTIs) in patients hospitalized in January–June 2020 in central Poland. Antimicrobial susceptibility testing was performed using the disk-diffusion method. Escherichia coli (52.2%), Klebsiella pneumoniae (13.7%), Enterococcus faecalis (9.3%), E. faecium (6.2%), and Proteus mirabilis (4,3%) were most commonly isolated from urine samples. E. coli was significantly more frequent in women (58.6%) (p = 0.0089) and in the age group 0–18, while K. pneumoniae was more frequent in men (24.4%) (p = 0.0119) and in individuals aged 40–60 and >60. Gram-negative species showed resistance to ampicillin. K. pneumoniae were resistant to amoxicillin plus clavulanic acid (75.0%), piperacillin plus tazobactam (76.2%), cefotaxime (76.2%), cefuroxime (81.0%), ciprofloxacin (81.0%), and trimethoprim plus sulphamethoxazole (81.0%). Carbapenems were effective against all E. coli and P. mirabilis. Some K. pneumoniae (13.6%) produced metallo-β-lactamases (MBLs). E. coli (22.6%), K. pneumoniae (81.8%), and all E. faecium were multidrug-resistant (MDR). Some E. coli (26.2%), K. pneumoniae (63.6%), and P. mirabilis (14.3%) isolates produced extended-spectrum beta-lactamases (ESBL). Vancomycin-resistant E. faecium was also found. This study showed that the possibilities of UTIs therapy using available antibiotics become limited due to the increasing number of antibiotic-resistant uropathogens.

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Three-Year Trend in Escherichia coli Antimicrobial Resistance among Children’s Urine Cultures in an Italian Metropolitan Area

Children ◽

10.3390/children8070597 ◽

2021 ◽

Vol 8 (7) ◽

pp. 597

Author(s):

Luca Pierantoni ◽

Laura Andreozzi ◽

Simone Ambretti ◽

Arianna Dondi ◽

Carlotta Biagi ◽

...

Keyword(s):

Escherichia Coli ◽

Metropolitan Area ◽

Bacterial Infections ◽

Asymptomatic Bacteriuria ◽

Multidrug Resistant ◽

Resistance Rate ◽

First Line ◽

E Coli ◽

First Line Therapy ◽

Tract Infections

Urinary tract infections (UTIs) are among the most common bacterial infections in children, and Escherichia coli is the main pathogen responsible. Several guidelines, including the recently updated Italian guidelines, recommend amoxicillin-clavulanic acid (AMC) as a first-line antibiotic therapy in children with febrile UTIs. Given the current increasing rates of antibiotic resistance worldwide, this study aimed to investigate the three-year trend in the resistance rate of E. coli isolated from pediatric urine cultures (UCs) in a metropolitan area of northern Italy. We conducted a retrospective review of E. coli-positive, non-repetitive UCs collected in children aged from 1 month to 14 years, regardless of a diagnosis of UTI, catheter colonization, urine contamination, or asymptomatic bacteriuria. During the study period, the rate of resistance to AMC significantly increased from 17.6% to 40.2% (p < 0.001). Ciprofloxacin doubled its resistance rate from 9.1% to 16.3% (p = 0.007). The prevalence of multidrug-resistant E. coli rose from 3.9% to 9.2% (p = 0.015). The rate of resistance to other considered antibiotics remained stable, as did the prevalence of extended spectrum beta-lactamases and extensively resistant E. coli among isolates. These findings call into question the use of AMC as a first-line therapy for pediatric UTIs in our population, despite the indications of recent Italian guidelines.

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