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Fulltext Lineage-Specific Methyltransferases Define the Methylome of the Globally Disseminated Escherichia coli ST131 Clone

Forde BM, Phan MD, Gawthorne JA, Ashcroft MM, Stanton-Cook M, Sarkar S, et al.

mBio, 2015 Nov 17;6(6):e01602-15.
PMID: 26578678 DOI: 10.1128/mBio.01602-15

Escherichia coli sequence type 131 (ST131) is a clone of uropathogenic E. coli that has emerged rapidly and disseminated globally in both clinical and community settings. Members of the ST131 lineage from across the globe have been comprehensively characterized in terms of antibiotic resistance, virulence potential, and pathogenicity, but to date nothing is known about the methylome of these important human pathogens. Here we used single-molecule real-time (SMRT) PacBio sequencing to determine the methylome of E. coli EC958, the most-well-characterized completely sequenced ST131 strain. Our analysis of 52,081 methylated adenines in the genome of EC958 discovered three (m6)A methylation motifs that have not been described previously. Subsequent SMRT sequencing of isogenic knockout mutants identified the two type I methyltransferases (MTases) and one type IIG MTase responsible for (m6)A methylation of novel recognition sites. Although both type I sites were rare, the type IIG sites accounted for more than 12% of all methylated adenines in EC958. Analysis of the distribution of MTase genes across 95 ST131 genomes revealed their prevalence is highly conserved within the ST131 lineage, with most variation due to the presence or absence of mobile genetic elements on which individual MTase genes are located.
IMPORTANCE: DNA modification plays a crucial role in bacterial regulation. Despite several examples demonstrating the role of methyltransferase (MTase) enzymes in bacterial virulence, investigation of this phenomenon on a whole-genome scale has remained elusive until now. Here we used single-molecule real-time (SMRT) sequencing to determine the first complete methylome of a strain from the multidrug-resistant E. coli sequence type 131 (ST131) lineage. By interrogating the methylome computationally and with further SMRT sequencing of isogenic mutants representing previously uncharacterized MTase genes, we defined the target sequences of three novel ST131-specific MTases and determined the genomic distribution of all MTase target sequences. Using a large collection of 95 previously sequenced ST131 genomes, we identified mobile genetic elements as a major factor driving diversity in DNA methylation patterns. Overall, our analysis highlights the potential for DNA methylation to dramatically influence gene regulation at the transcriptional level within a well-defined E. coli clone.

Matched MeSH terms: Escherichia coli Infections/microbiology
Fulltext Discovery of New Genes Involved in Curli Production by a Uropathogenic Escherichia coli Strain from the Highly Virulent O45:K1:H7 Lineage

Nhu NTK, Phan MD, Peters KM, Lo AW, Forde BM, Min Chong T, et al.

mBio, 2018 08 21;9(4).
PMID: 30131362 DOI: 10.1128/mBio.01462-18

Curli are bacterial surface-associated amyloid fibers that bind to the dye Congo red (CR) and facilitate uropathogenic Escherichia coli (UPEC) biofilm formation and protection against host innate defenses. Here we sequenced the genome of the curli-producing UPEC pyelonephritis strain MS7163 and showed it belongs to the highly virulent O45:K1:H7 neonatal meningitis-associated clone. MS7163 produced curli at human physiological temperature, and this correlated with biofilm growth, resistance of sessile cells to the human cationic peptide cathelicidin, and enhanced colonization of the mouse bladder. We devised a forward genetic screen using CR staining as a proxy for curli production and identified 41 genes that were required for optimal CR binding, of which 19 genes were essential for curli synthesis. Ten of these genes were novel or poorly characterized with respect to curli synthesis and included genes involved in purine de novo biosynthesis, a regulator that controls the Rcs phosphorelay system, and a novel repressor of curli production (referred to as rcpA). The involvement of these genes in curli production was confirmed by the construction of defined mutants and their complementation. The mutants did not express the curli major subunit CsgA and failed to produce curli based on CR binding. Mutation of purF (the first gene in the purine biosynthesis pathway) and rcpA also led to attenuated colonization of the mouse bladder. Overall, this work has provided new insight into the regulation of curli and the role of these amyloid fibers in UPEC biofilm formation and pathogenesis.IMPORTANCE Uropathogenic Escherichia coli (UPEC) strains are the most common cause of urinary tract infection, a disease increasingly associated with escalating antibiotic resistance. UPEC strains possess multiple surface-associated factors that enable their colonization of the urinary tract, including fimbriae, curli, and autotransporters. Curli are extracellular amyloid fibers that enhance UPEC virulence and promote biofilm formation. Here we examined the function and regulation of curli in a UPEC pyelonephritis strain belonging to the highly virulent O45:K1:H7 neonatal meningitis-associated clone. Curli expression at human physiological temperature led to increased biofilm formation, resistance of sessile cells to the human cationic peptide LL-37, and enhanced bladder colonization. Using a comprehensive genetic screen, we identified multiple genes involved in curli production, including several that were novel or poorly characterized with respect to curli synthesis. In total, this study demonstrates an important role for curli as a UPEC virulence factor that promotes biofilm formation, resistance, and pathogenesis.

Matched MeSH terms: Escherichia coli Infections/microbiology
Fulltext T4-like coliphage ΦKAZ14 virulent to pathogenic and extended spectrum β-lactamase-producing Escherichia coli of poultry origin

Ahmad KA, Mohanmmed AS, Abas F, Chin SC

Virol Sin, 2015 Feb;30(1):73-5.
PMID: 25662886 DOI: 10.1007/s12250-014-3541-8
Matched MeSH terms: Escherichia coli Infections/microbiology*
Fulltext Loop-mediated isothermal amplification assay for detection of generic and verocytotoxin-producing Escherichia coli among indigenous individuals in Malaysia

Teh CS, Chua KH, Lim YA, Lee SC, Thong KL

ScientificWorldJournal, 2014;2014:457839.
PMID: 24967435 DOI: 10.1155/2014/457839

We have successfully developed a Loop-mediated isothermal amplification (LAMP) assay that could specifically detect generic Escherichia coli (E. coli). This assay was tested on 85 bacterial strains and successfully identified 54 E. coli strains (average threshold time, Tt = 21.26). The sensitivity of this assay was evaluated on serial dilutions of bacterial cultures and spiked faeces. The assay could detect 10(2) CFU/mL for bacterial culture with Tt = 33.30 while the detection limit for spiked faeces was 10(3) CFU/mL (Tt = 31.12). We have also detected 46 generic E. coli from 50 faecal samples obtained from indigenous individuals with 16% of the positive samples being verocytotoxin-producing E. coli (VTEC) positive. VT1/VT2 allele was present in one faecal sample while the ratio of VT1 to VT2 was 6 : 1. Overall, our study had demonstrated high risk of VTEC infection among the indigenous community and most of the asymptomatic infection occurred among those aged below 15 years. The role of asymptomatic human carriers as a source of dissemination should not be underestimated. Large scale screening of the VTEC infection among indigenous populations and the potential contamination sources will be possible and easy with the aid of this newly developed rapid and simple LAMP assay.

Matched MeSH terms: Escherichia coli Infections/microbiology*
Fulltext Characteristics of childhood diarrhea associated with enterotoxigenic Escherichia coli in Malaysia

Samuel S, Vadivelu J, Parasakthi N

Southeast Asian J. Trop. Med. Public Health, 1997 Mar;28(1):114-9.
PMID: 9322293

Amongst 107 diarrheal cases studied a bacterial agent was isolated from 71 (66%) cases of which 60 (85%) were due to a single agent and the remaining 11 (15%) were of mixed infections. Enterotoxigenic Escherichia coli (ETEC) was isolated from 65 cases. Other pathogens isolated included Salmonella spp, Shigella spp and rotavirus. There was a higher isolation rate of ETEC from females and rotavirus from males. The infection rate was found to higher for the 0-2 year age group as compared to the 3-5 year age group. Amongst the ETEC isolated the STa 2 toxotype was the predominant type.

Matched MeSH terms: Escherichia coli Infections/microbiology*
Antibiotic resistance, plasmid profile and RAPD-PCR analysis of enteropathogenic Escherichia coli (EPEC) clinical isolates

Wan KF, Radu S, Cheah YK, Benjamin PG, Ling CM, Hon SF, et al.

Southeast Asian J. Trop. Med. Public Health, 2003 Sep;34(3):620-6.
PMID: 15115139

Enteropathogenic Escherichia coli (EPEC) is a leading cause of diarrhea among infants in developing countries. A total of 38 EPEC isolates, obtained from diarrhea patients of Hospital Miri, Sarawak, were investigated through plasmid profile, antibiotic resistance and randomly amplified polymorphic DNA (RAPD) analysis. From the 8 types of antibiotics used, all isolates were 100% resistant to furoxime, cephalothin and sulphamethoxazole and showed high multiple antibiotic resistant (MAR) indexes, ranging from 0.5 to 1.0. In plasmid profiling, 22 isolates (58%) showed the presence of one or more plasmids in the range 1.0 to 30.9 mDa. The dendrogram obtained from the results of the RAPD-PCR discriminated the isolates into 30 single isolates and 3 clusters at the level of 40% similarity. The EPEC isolates were highly diverse, as shown by their differing plasmid profiles, antibiotic resistance patterns and RAPD profiles.

Matched MeSH terms: Escherichia coli Infections/microbiology*
Enteropathogenic Escherichia coli diarrhoea in Malaysian children

Jegathesan M, Singh RB, Kanaganayagy M, Soon LE

Southeast Asian J. Trop. Med. Public Health, 1975 Mar;6(1):61-7.
PMID: 1096307
Matched MeSH terms: Escherichia coli Infections/microbiology*
ENTEROAGGREGATIVE ESCHERICHIA COLI O104 FROM THAI AND IMPORTED MALAYSIAN RAW BEEF

Wameadesa N, Sae-lim A, Hayeebilan F, Rattanachuay P, Sukhumungoon P

Southeast Asian J. Trop. Med. Public Health, 2017 Mar;48(2):338-50.
PMID: 29642296

Local Thai and imported Malaysian beef in southern Thailand area carry
several Shiga toxin-producing Escherichia coli (STEC) serotypes. STEC O104 is an
important pathogen capable of causing outbreaks with considerable morbidity
and mortality. This study investigated the presence of E. coli O104 from local Thai
and imported Malaysian beef obtained from markets in Hat Yai City, Songkhla
Province during August 2015 - February 2016. Thirty-one E. coli O104 strains
were isolated from 12 beef samples (16% and 23% Thai and imported Malaysian,
respectively). Thirty strains possessed aggA (coding for a major component of
AAF/I fimbriae), a gene associated with enteroaggregative E. coli (EAEC) pathotype,
and all strains carried fimH (encoding Type 1 fimbriae). Thirty strains
belonged to phylogenetic group B1 and one strain (from Malaysian beef) to group
A. Agglutination of yeast cells was observed among 29 E. coli O104 strains. Investigation
of stx2 phage occupancy loci demonstrated that sbcB was occupied in 12
strains. Antimicrobial susceptibility assay revealed that 7 strains were resistant
to at least one antimicrobial agent and two were multi-drug resistant. One strain
carried extended spectrum β-lactamase gene blaCTX-M and three carried blaTEM. PFGE-generated DNA profiling showed identical DNA pattern between that of
one EAEC O104 strain from Thai beef and another from Malaysian beef, indicating
that these two strains originated from the same clone. This is the first report
in Thailand describing the presence of EAEC O104 from both Thai and imported
Malaysian beef and their transfer between both countries. Thorough surveillance
of this pathogen in fresh meats and vegetables should help to prevent any possible
outbreak of E. coli O104.

Matched MeSH terms: Escherichia coli Infections/microbiology
Fatal Leptospirosis and Escherichia coli co-infection in a post-partum woman

Tan TL, Lee LY, Lim WC

Med J Malaysia, 2018 12;73(6):427-429.
PMID: 30647223

The occurrence of Leptospirosis and Escherichia coli coinfection in the post-partum period is a novel case. This report illustrated a previously well woman from a suburban area presented with acute neurological deterioration following a two days history of fever during her puerperal period. Early interventions with fluids, broad spectrum antibiotics and intensive supportive care were given. Despite that, she deteriorated rapidly and developed pulmonary hemorrhage, disseminated intravascular coagulopathy, and multi-organ failure. She succumbed within 12 hours of admission. The knowledge about such fatal co-infections should be disseminated to medical practitioners encountering Leptospirosis infection and general public.

Matched MeSH terms: Escherichia coli Infections/microbiology
Fulltext The higher prevalence of extended spectrum beta-lactamases among Escherichia coli ST131 in Southeast Asia is driven by expansion of a single, locally prevalent subclone

Chen SL, Ding Y, Apisarnthanarak A, Kalimuddin S, Archuleta S, Omar SFS, et al.

Sci Rep, 2019 09 13;9(1):13245.
PMID: 31519972 DOI: 10.1038/s41598-019-49467-5

The ST131 multilocus sequence type (MLST) of Escherichia coli is a globally successful pathogen whose dissemination is increasing rates of antibiotic resistance. Numerous global surveys have demonstrated the pervasiveness of this clone; in some regions ST131 accounts for up to 30% of all E. coli isolates. However, many regions are underrepresented in these published surveys, including Africa, South America, and Asia. We collected consecutive bloodstream E. coli isolates from three countries in Southeast Asia; ST131 was the most common MLST type. As in other studies, the C2/H30Rx clade accounted for the majority of ST131 strains. Clinical risk factors were similar to other reported studies. However, we found that nearly all of the C2 strains in this study were closely related, forming what we denote the SEA-C2 clone. The SEA-C2 clone is enriched for strains from Asia, particularly Southeast Asia and Singapore. The SEA-C2 clone accounts for all of the excess resistance and virulence of ST131 relative to non-ST131 E. coli. The SEA-C2 strains appear to be locally circulating and dominant in Southeast Asia, despite the intuition that high international connectivity and travel would enable frequent opportunities for other strains to establish themselves.

Matched MeSH terms: Escherichia coli Infections/microbiology
Fulltext The complete genome sequence of Escherichia coli EC958: a high quality reference sequence for the globally disseminated multidrug resistant E. coli O25b:H4-ST131 clone

Forde BM, Ben Zakour NL, Stanton-Cook M, Phan MD, Totsika M, Peters KM, et al.

PLoS One, 2014;9(8):e104400.
PMID: 25126841 DOI: 10.1371/journal.pone.0104400

Escherichia coli ST131 is now recognised as a leading contributor to urinary tract and bloodstream infections in both community and clinical settings. Here we present the complete, annotated genome of E. coli EC958, which was isolated from the urine of a patient presenting with a urinary tract infection in the Northwest region of England and represents the most well characterised ST131 strain. Sequencing was carried out using the Pacific Biosciences platform, which provided sufficient depth and read-length to produce a complete genome without the need for other technologies. The discovery of spurious contigs within the assembly that correspond to site-specific inversions in the tail fibre regions of prophages demonstrates the potential for this technology to reveal dynamic evolutionary mechanisms. E. coli EC958 belongs to the major subgroup of ST131 strains that produce the CTX-M-15 extended spectrum β-lactamase, are fluoroquinolone resistant and encode the fimH30 type 1 fimbrial adhesin. This subgroup includes the Indian strain NA114 and the North American strain JJ1886. A comparison of the genomes of EC958, JJ1886 and NA114 revealed that differences in the arrangement of genomic islands, prophages and other repetitive elements in the NA114 genome are not biologically relevant and are due to misassembly. The availability of a high quality uropathogenic E. coli ST131 genome provides a reference for understanding this multidrug resistant pathogen and will facilitate novel functional, comparative and clinical studies of the E. coli ST131 clonal lineage.

Matched MeSH terms: Escherichia coli Infections/microbiology
Fulltext Titanium Dioxide Nanoparticle-Based Interdigitated Electrodes: A Novel Current to Voltage DNA Biosensor Recognizes E. coli O157:H7

Nadzirah Sh, Azizah N, Hashim U, Gopinath SC, Kashif M

PLoS One, 2015;10(10):e0139766.
PMID: 26445455 DOI: 10.1371/journal.pone.0139766

Nanoparticle-mediated bio-sensing promoted the development of novel sensors in the front of medical diagnosis. In the present study, we have generated and examined the potential of titanium dioxide (TiO2) crystalline nanoparticles with aluminium interdigitated electrode biosensor to specifically detect single-stranded E.coli O157:H7 DNA. The performance of this novel DNA biosensor was measured the electrical current response using a picoammeter. The sensor surface was chemically functionalized with (3-aminopropyl) triethoxysilane (APTES) to provide contact between the organic and inorganic surfaces of a single-stranded DNA probe and TiO2 nanoparticles while maintaining the sensing system's physical characteristics. The complement of the target DNA of E. coli O157:H7 to the carboxylate-probe DNA could be translated into electrical signals and confirmed by the increased conductivity in the current-to-voltage curves. The specificity experiments indicate that the biosensor can discriminate between the complementary sequences from the base-mismatched and the non-complementary sequences. After duplex formation, the complementary target sequence can be quantified over a wide range with a detection limit of 1.0 x 10(-13)M. With target DNA from the lysed E. coli O157:H7, we could attain similar sensitivity. Stability of DNA immobilized surface was calculated with the relative standard deviation (4.6%), displayed the retaining with 99% of its original response current until 6 months. This high-performance interdigitated DNA biosensor with high sensitivity, stability and non-fouling on a novel sensing platform is suitable for a wide range of biomolecular interactive analyses.

Matched MeSH terms: Escherichia coli Infections/microbiology
Fulltext Detection and characterization of ESBL-producing Enterobacteriaceae from the gut of healthy chickens, Gallus gallus domesticus in rural Nepal: Dominance of CTX-M-15-non-ST131 Escherichia coli clones

Hosuru Subramanya S, Bairy I, Nayak N, Amberpet R, Padukone S, Metok Y, et al.

PLoS One, 2020;15(5):e0227725.
PMID: 32469888 DOI: 10.1371/journal.pone.0227725

The surge in the prevalence of drug-resistant bacteria in poultry is a global concern as it may pose an extended threat to humans and animal health. The present study aimed to investigate the colonization proportion of extended-spectrum β-lactamase (ESBL) and carbapenemase-producing Enterobacteriaceae (EPE and CPE, respectively) in the gut of healthy poultry, Gallus gallus domesticus in Kaski district of Western Nepal. Total, 113 pooled rectal swab specimens from 66 private household farms and 47 commercial poultry farms were collected by systematic random sampling from the Kaski district in western Nepal. Out of 113 pooled samples, 19 (28.8%) samples from 66 backyard farms, and 15 (31.9%) from 47 commercial broiler farms were positive for EPE. Of the 38 EPE strains isolated from 34 ESBL positive rectal swabs, 31(81.6%) were identified as Escherichia coli, five as Klebsiella pneumoniae (13.2%), and one each isolate of Enterobacter species and Citrobacter species (2.6%). Based on genotyping, 35/38 examined EPE strains (92.1%) were phylogroup-1 positive, and all these 35 strains (100%) had the CTX-M-15 gene and strains from phylogroup-2, and 9 were of CTX-M-2 and CTX-M-14, respectively. Among 38 ESBL positive isolates, 9 (23.7%) were Ambler class C (Amp C) co-producers, predominant were of DHA, followed by CIT genes. Two (6.5%) E. coli strains of ST131 belonged to clade C, rest 29/31 (93.5%) were non-ST131 E. coli. None of the isolates produced carbapenemase. Twenty isolates (52.6%) were in-vitro biofilm producers. Univariate analysis showed that the odd of ESBL carriage among commercial broilers were 1.160 times (95% CI 0.515, 2.613) higher than organically fed backyard flocks. This is the first study in Nepal, demonstrating the EPE colonization proportion, genotypes, and prevalence of high-risk clone E. coli ST131 among gut flora of healthy poultry. Our data indicated that CTX-M-15 was the most prevalent ESBL enzyme, mainly associated with E. coli belonging to non-ST131clones and the absence of carbapenemases.

Matched MeSH terms: Escherichia coli Infections/microbiology
Fulltext Shiga toxin sub-type 2a increases the efficiency of Escherichia coli O157 transmission between animals and restricts epithelial regeneration in bovine enteroids

Fitzgerald SF, Beckett AE, Palarea-Albaladejo J, McAteer S, Shaaban S, Morgan J, et al.

PLoS Pathog, 2019 10;15(10):e1008003.
PMID: 31581229 DOI: 10.1371/journal.ppat.1008003

Specific Escherichia coli isolates lysogenised with prophages that express Shiga toxin (Stx) can be a threat to human health, with cattle being an important natural reservoir. In many countries the most severe pathology is associated with enterohaemorrhagic E. coli (EHEC) serogroups that express Stx subtype 2a. In the United Kingdom, phage type (PT) 21/28 O157 strains have emerged as the predominant cause of life-threatening EHEC infections and this phage type commonly encodes both Stx2a and Stx2c toxin types. PT21/28 is also epidemiologically linked to super-shedding (>103 cfu/g of faeces) which is significant for inter-animal transmission and human infection as demonstrated using modelling studies. We demonstrate that Stx2a is the main toxin produced by stx2a+/stx2c+ PT21/28 strains induced with mitomycin C and this is associated with more rapid induction of gene expression from the Stx2a-encoding prophage compared to that from the Stx2c-encoding prophage. Bacterial supernatants containing either Stx2a and/or Stx2c were demonstrated to restrict growth of bovine gastrointestinal organoids with no restriction when toxin production was not induced or prevented by mutation. Isogenic strains that differed in their capacity to produce Stx2a were selected for experimental oral colonisation of calves to assess the significance of Stx2a for both super-shedding and transmission between animals. Restoration of Stx2a expression in a PT21/28 background significantly increased animal-to-animal transmission and the number of sentinel animals that became super-shedders. We propose that while both Stx2a and Stx2c can restrict regeneration of the epithelium, it is the relatively rapid and higher levels of Stx2a induction, compared to Stx2c, that have contributed to the successful emergence of Stx2a+ E. coli isolates in cattle in the last 40 years. We propose a model in which Stx2a enhances E. coli O157 colonisation of in-contact animals by restricting regeneration and turnover of the colonised gastrointestinal epithelium.

Matched MeSH terms: Escherichia coli Infections/microbiology
Fulltext Population dynamics of an Escherichia coli ST131 lineage during recurrent urinary tract infection

Forde BM, Roberts LW, Phan MD, Peters KM, Fleming BA, Russell CW, et al.

Nat Commun, 2019 08 13;10(1):3643.
PMID: 31409795 DOI: 10.1038/s41467-019-11571-5

Recurrent urinary tract infections (rUTIs) are extremely common, with ~ 25% of all women experiencing a recurrence within 1 year of their original infection. Escherichia coli ST131 is a globally dominant multidrug resistant clone associated with high rates of rUTI. Here, we show the dynamics of an ST131 population over a 5-year period from one elderly woman with rUTI since the 1970s. Using whole genome sequencing, we identify an indigenous clonal lineage (P1A) linked to rUTI and persistence in the fecal flora, providing compelling evidence of an intestinal reservoir of rUTI. We also show that the P1A lineage possesses substantial plasmid diversity, resulting in the coexistence of antibiotic resistant and sensitive intestinal isolates despite frequent treatment. Our longitudinal study provides a unique comprehensive genomic analysis of a clonal lineage within a single individual and suggests a population-wide resistance mechanism enabling rapid adaptation to fluctuating antibiotic exposure.

Matched MeSH terms: Escherichia coli Infections/microbiology*
Genetic characterization of Escherichia coli O157: H7/- strains carrying the stx2 gene but not producing Shiga toxin 2

Koitabashi T, Vuddhakul V, Radu S, Morigaki T, Asai N, Nakaguchi Y, et al.

Microbiol. Immunol., 2006;50(2):135-48.
PMID: 16490932

Nine Escherichia coli O157: H7/- strains isolated primarily from non-clinical sources in Thailand and Japan carried the stx(2) gene but did not produce Stx2 toxin in a reversed passive latex agglutination (RPLA) assay. A strain (EDL933) bearing a stx(2) phage (933W) was compared to a strain (Thai-12) that was Stx2-negative but contained the stx(2) gene. To study the lack of Stx2 production, the Thai-12 stx(2) gene and its upstream nucleotide sequence were analyzed. The Thai-12 stx(2) coding region was intact and Stx2 was expressed from a cloned stx(2) gene using a plasmid vector and detected using RPLA. A lacZ fusion analysis found the Thai-12 stx(2) promoter non-functional. Because the stx(2) gene is downstream of the late promoter in the stx(2) phage genome, the antitermination activity of Q protein is essential for strong stx(2) transcription. Thai-12 had the q gene highly homologous to that of Phi21 phage but not to the 933W phage. High-level expression of exogenous q genes demonstrated Q antitermination activity was weak in Thai-12. Replication of stx(2) phage was not observed in Stx2-negative strains. The q-stx(2) gene sequence of Thai-12 was well conserved in all Stx2-negative strains. A PCR assay to detect the Thai-12 q-stx(2) sequence demonstrated that 30% of O157 strains from marketed Malaysian beef carried this sequence and they produced little or no Stx2. These results suggest that stx(2)-positive O157 strains that produce little or no Stx2 may be widely distributed in the Asian environment.

Matched MeSH terms: Escherichia coli Infections/microbiology*
Mucosal and systemic responses of immunogenic vaccines candidates against enteric Escherichia coli infections in ruminants: A review

Lawan A, Jesse FFA, Idris UH, Odhah MN, Arsalan M, Muhammad NA, et al.

Microb Pathog, 2018 Apr;117:175-183.
PMID: 29471137 DOI: 10.1016/j.micpath.2018.02.039

Innumerable Escherichia coli of animal origin are identified, which are of economic significance, likewise, cattle, sheep and goats are the carrier of enterohaemorrhagic E. coli, which are less pathogenic, and can spread to people by way of direct contact and through the contamination of foodstuff or portable drinking water, causing serious illness. The immunization of ruminants has been carried out for ages and is largely acknowledged as the most economical and maintainable process of monitoring E. coli infection in ruminants. Yet, only a limited number of E. coli vaccines are obtainable. Mucosal surfaces are the most important ingress for E. coli and thus mucosal immune responses function as the primary means of fortification. Largely contemporary vaccination processes are done by parenteral administration and merely limited number of E. coli vaccines are inoculated via mucosal itinerary, due to its decreased efficacy. Nevertheless, aiming at maximal mucosal partitions to stimulate defensive immunity at both mucosal compartments and systemic site epitomises a prodigious task. Enormous determinations are involved in order to improve on novel mucosal E. coli vaccines candidate by choosing apposite antigens with potent immunogenicity, manipulating novel mucosal itineraries of inoculation and choosing immune-inducing adjuvants. The target of E. coli mucosal vaccines is to stimulate a comprehensive, effective and defensive immunity by specifically counteracting the antibodies at mucosal linings and by the stimulation of cellular immunity. Furthermore, effective E. coli mucosal vaccine would make vaccination measures stress-free and appropriate for large number of inoculation. On account of contemporary advancement in proteomics, metagenomics, metabolomics and transcriptomics research, a comprehensive appraisal of the immeasurable genes and proteins that were divulged by a bacterium is now in easy reach. Moreover, there exist marvellous prospects in this bourgeoning technologies in comprehending the host bacteria affiliation. Accordingly, the flourishing knowledge could massively guarantee to the progression of immunogenic vaccines against E. coli infections in both humans and animals. This review highlight and expounds on the current prominence of mucosal and systemic immunogenic vaccines for the prevention of E. coli infections in ruminants.

Matched MeSH terms: Escherichia coli Infections/microbiology
Prevalence and characterization of multidrug-resistant and extended-spectrum beta-lactamase-producing Escherichia coli from pediatric wards of a Malaysian hospital

Ho WS, Balan G, Puthucheary S, Kong BH, Lim KT, Tan LK, et al.

Microb Drug Resist, 2012 Aug;18(4):408-16.
PMID: 22394084 DOI: 10.1089/mdr.2011.0222

The emergence of Escherichia coli resistant to extended-spectrum cephalosporins (ESCs) is of concern as ESC is often used to treat infections by Gram-negative bacteria. One-hundred and ten E. coli strains isolated in 2009-2010 from children warded in a Malaysian tertiary hospital were analyzed for their antibiograms, carriage of extended-spectrum beta-lactamase (ESBL) and AmpC genes, possible inclusion of the beta-lactamase genes on an integron platform, and their genetic relatedness. All E. coli strains were sensitive to carbapenems. About 46% of strains were multidrug resistant (MDR; i.e., resistant to ≥3 antibiotic classes) and almost half (45%) were nonsusceptible to ESCs. Among the MDR strains, high resistance rates were observed for ampicillin (98%), tetracycline (75%), and trimethoprim/sulfamethoxazole (73%). Out of 110 strains, bla(TEM-1) (49.1%), bla(CTX-M) (11.8%), and bla(CMY-2) (6.4%) were detected. Twenty-one strains were ESBL producers. CTX-M-15 was the predominant CTX-M variant found and this is the first report of a CTX-M-27-producing E. coli strain from Malaysia. Majority (3.1%) of the strains harbored class 1 integron-encoded integrases with a predominance of aadA and dfr genes within the integron variable region. No gene cassette encoding ESBL genes was found and integrons were not significantly associated with ESBL or non-ESBL producers. Possible clonal expansion was observed for few CTX-M-15-positive strains but the O25-ST131 E. coli clone known to harbor CTX-M-15 was not detected while CMY-2-positive strains were genetically diverse.

Matched MeSH terms: Escherichia coli Infections/microbiology*
Characteristics of a phage effective for colibacillosis control in poultry

Lau GL, Sieo CC, Tan WS, Ho YW

J Sci Food Agric, 2012 Oct;92(13):2657-63.
PMID: 22505020 DOI: 10.1002/jsfa.5683

Colibacillosis is one of the main causes of economic loss in the poultry industry worldwide. Although antibiotics have been used to control this infection, the emergence of antibiotic-resistant bacteria poses a threat to animal and human health. Phage therapy has been reported as one of the potential alternative methods to control bacterial infections. However, efficient phage therapy is highly dependent on the characteristics of the phage isolated. In the present study the characteristics of a lytic phage, ØEC1, which was found to be effective against the causative agent of colibacillosis in chickens in a previous in vivo study, are reported.

Matched MeSH terms: Escherichia coli Infections/microbiology
Cephalhematoma infected by Escherichia coli presenting as an extensive scalp abscess

Wong CS, Cheah FC

J Pediatr Surg, 2012 Dec;47(12):2336-40.
PMID: 23217901 DOI: 10.1016/j.jpedsurg.2012.09.029

Cephalhematoma is normally a self-limiting condition affecting 1%-2% of live births, especially following instrumental forceps delivery. The sub-periosteal bleed is characteristically limited by the cranial sutures. Although benign in most instances, this condition may, in a small proportion of cases, be complicated by hyperbilirubinemia or scalp infection. We describe a case of cephalhematoma in a newborn infant infected with Escherichia coli resulting in an extensive deep seated scalp abscess. The infection was also systemic causing E. coli septicemia and initial assessment assumed local extension including bone and meningeal to cause skull osteomyelitis and meningitis respectively. Further investigations and multiple-modality imaging with ultrasound, CT scan and bone scintigraphy outlined the involvement as limited to the scalp, resulting in a shorter antibiotic treatment period and earlier discharge from hospital. The infant recovered well with parenteral antibiotics, saucerization of the abscess and a later skin grafting procedure.

Matched MeSH terms: Escherichia coli Infections/microbiology*

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