H7 Isolates Research Articles

RETRACTED ARTICLE: Occurrence and antimicrobial susceptibility profile of Escherichia coli O157:H7 from food of animal origin in Bishoftu town, Central Ethiopia

BackgroundEscherichia coli O157:H7 (E. coli O157:H7) have frequently been associated with food borne illness and are considered as most serious of known food borne pathogens leading to severe illnesses and high mortality rates in humans. Most of outbreaks were traced to raw meat and raw milk consumption, as well as to dairy products such as yogurt and cheese derived from raw milk.ResultsOut of 200 samples examined, 40 (20%) and 7 (3.5%) of the samples were positive to E. coli and E. coli O157:H7 respectively. The highest isolation of E. coli was from cheese (40%), followed by raw milk (32%), yogurt (25.71%), beef (13.84%), and pasteurized milk (0%). Among E. coli O157:H7 isolates, the highest isolation was from raw milk (12%) followed by cheese (5.71%) and meat (3.07%). However, no E. coli O157:H7 was isolated from pasteurized milk and yogurt. Antibiotic susceptibility profile showed that E. coli was resistant for vancomycin (89.74%), ampicillin (76.92%) and streptomycin (69.23%). The analysis showed that, 92.5% of isolates showed multidrug resistance comprising 2–4 antimicrobials.ConclusionThe occurrence of E. coli O157:H7 and its multiple antibiotic resistant profiles shows a risk for public health and food safety as well as animal production. These findings stress the need for an integrated control of E. coli O157:H7 from farm production to consumption of food of animal origin.

Detección y caracterización de Escherichia coli productor de toxina Shiga en niños atendidos en un hospital pediátrico interzonal de la ciudad de La Plata

Shiga toxin-producing Escherichia coli (STEC) is a foodborne pathogen that can cause watery diarrhea, bloody diarrhea (BD), and hemolytic uremic syndrome (HUS). The objective of this study was to determine the phenotypic and genotypic profiles of STEC strains isolated from children with BD and HUS treated at a pediatric hospital in the city of La Plata in the period 2006-2012, and to establish the clonal relationship of O157:H7 isolates by pulsed field electrophoresis. The percentage of positive samples was 4.9% and 39.2% in patients with BD and HUS, respectively. Seventy-seven STEC strains from 10 different serotypes were isolated, with 100% colony recovery, O157:H7 being the most frequent (71.4%) serotype, followed by O145:NM (15.6%). An average of 98.2% of O157:H7 isolates belonged to biotype C and were sensitive to all the antibiotics tested. All of them (100%) carried genotype stx2, eae, fliCH7, ehxA, iha, efa, toxB, lpfA1-3 and lpfA2-2. When the clonal relationship of the O157:H7 strains was studied, a total of 42 patterns with at least 88% similarity were identified, and 6 clusters with identical profiles were established. The eae-negative isolates belonged to serotypes O59:H19, O102:H6, O174:NM and O174:H21. The strains O59:H19 and O174:H21 were positive for the aggR gene. This study shows that STEC of different serotypes and genotypes circulate in the city of La Plata and surroundings. Despite the genetic diversity observed between the O157:H7 isolates, some were indistinguishable by the subtyping techniques used.

Risk Analysis and Antibiogram Spectrum of <i>Escherichia coli</i> O157: H7 Serotype from Children Stool and Raw Bovine Meat in Households Across Cross River State, Nigeria

This cross sectional study is aimed at evaluating the risk factors and antibiogram profiles of <i>Escherichia coli</i> O157:H7 in children stool and bovine meat obtained from selected households across Cross River State, Southern Nigeria. A total of 360 samples of fresh household bovine meat and 366 children diarrheal and nondiarrheal stool samples each were collected and examined for <i>E. coli</i> O157: H7 using standard culture and serological methods. Confirmed <i>E. coli</i> O157: H7 isolates were evaluated for antimicrobial susceptibility using the Agar disc diffusion method. The total positive samples for <i>E. coli</i> O157: H7 in household meat was 76/360 (21.11%,) while the diarrheaic and nondiarrheaic stool samples had 70/366 (19.13%) and 5/366 (1.37%) positive samples respectively. A significant difference was observed in the prevalence values among the bovine meat samples from various households and between the diarrheaic and nondiarrheaic samples at p<0.05. Risk factors such as <i>Age range</i> with highest prevalence value at 1-2yrs (26.83%); <i>Occupation of parent/guardian</i> with highest value from farming (25.67%) and <i>Main domestic water source</i> with highest value from surface water (28.21%) were observed to significantly affect the prevalence of the pathogen in children diarrheaic stool (p<0.05). All 70 diarrheaic isolates were resistant to one or multiple antibiotics with highest values obtained from tetracycline (88.6%) and cotrimoxazole (77.1%). This study revealed that bovine meat and some human and environmental factors play a vital role in the establishment of <i>E. coli</i> O157:H7 infection in children in the study communities with diarrheal stool being the main vehicle for secondary infections in humans. Cattle therefore serve as a major source of transmission of multi drug resistant <i>E. coli</i> O157:H7 to humans hence the need for continuous surveillance of this pathogen and implementation of legislation against indiscriminate use of antibiotics in diary farms.

Prevalence and Molecular Characterization of E. coli O157:H7 Isolated from Water Bodies in Ile-Ife and Environs

Water is one of the crucial necessities of man since it is needed for almost all of his activities. With increase in population growth, quality water needed for consumption by man is on the decline because of environmental pollution. Thus the main aim of this study was to investigate the prevalence level of E. coli O157:H7 in water bodies in Ile-Ife and its environs which are the sources of water for man’s consumption. Four hundred and fifty-one samples were investigated from five major sources of water namely; well, stream, borehole, bottled and sachet. The water samples were screened for E. coli and serologically characterized for E. coli O157:H7. The E. coli O157:H7 isolates obtained were further characterized for stx 1, stx 2 and eaeA genes. The result revealed that well water and stream water had a prevalence of 8.74% and 4.59% respectively. Antibiotic resistance profile of E. coli isolates showed that both sources harboured isolates that are resistant to three classes of antibiotics. The virulence gene distribution shows that stx 1 and stx 2 were present in all the E. coli O157:H7 investigated. In conclusion, it appears that the gastroenteritis outbreaks experienced in the study area may be due to the presence of E. coli O157:H7 in water samples.

Isolation and evaluation of cocktail phages for the control of multidrug-resistant Escherichia coli serotype O104: H4 and E. coli O157: H7 isolates causing diarrhea.

Escherichia coli serotype O157: H7 and E. coli O104: H4 are well known foodborne pathogens causing sever enteric illness. Using bacteriophages as biocontrol agents of some foodborne pathogens and multidrug-resistant (MDR) bacteria has a great attention nowadays. This study aims to test the effect of cocktail phages on the growth of some foodborne pathogens and MDR E. coli. Routine conventional PCR was used to confirm the identification of E. coli isolates. Double-layered culture technique was used to isolate phages from sewage water. Morphology of bacteriophage was described using transmission electron microscopy, and spot test was performed to determine host range of the phage cocktail. Phage cocktail of Siphoviridae and Podoviridae family infecting E. coli O157: H7, E. coli O104: H4 and untypeable E. coli (neither O157 nor O104) has been isolated from sewage water. Phage cocktail showed both lytic and lysogenic activity. Lytic activity was observed against E. coli O157: H7, E. coli O104: H4 isolates, Staphylococcus. aureus ATCC6538 and Pseudomonas aeruginosa ATCC 10145, while the lysogenic activity was observed against the untypeable strain. The tested phage cocktail showed a promising inhibitory action on E. coli O157: H7 and O104: H4, S. aureus ATCC6538 and P. aeruginosa ATCC 10145, suggesting the possibility of its use as a biocontrol tool or as natural food preservatives for many food products.

Incidence and antimicrobial susceptibility of Escherichia coli O157:H7 isolates recovered from dairy farms in Amathole District Municipality, Eastern Cape, South Africa

Incidence and antimicrobial susceptibility of Escherichia coli O157:H7 isolates recovered from dairy farms in Amathole District Municipality, Eastern Cape, South Africa

The frequency of shiga-like toxin (stx1 and stx2) and EHEC-hlyA in food by multiplex PCR

Abstract Aim: The aim of the present study was to determine the frequency of shiga-like toxin (stx1 and stx2) and drug resistance profiles food-borne Escherichia coli O157:H7 in Hatay province, Turkey. Methods: The presence of the virulence genes (stx1, stx2, hlyA) in a total of 150 E.coli isolates were studied with multiplex PCR. Results: A total of 327 salad samples were analyzed. E. coli O157:H7 was detected in 150 (45.8 %) out of 327 analyzed samples. Of these 150 isolates, the presence of hly-A gene was detected in 32 (21.3%) E.coli isolates. A total of five (15.6%) isolates in this 32 hlyA positive isolates had stx2 gene, two (6.3%) of them had stx1 gene and one (3.1%) of the isolates was found to be positive for both stx1 and stx2 genes. It was found that all E.coli O157:H7 isolates were resistant to erythromycin. While the highest rate of antibiotic resistance was observed for ampicillin (68.8%), no antibiotic resistance against cefuroxime, ciprofloxacin and cephaperasone was identified. Conclusions: The results obtained in our province showed that E.coli strains isolated from salad samples were found to have some important virulence genes such as stx1, stx2, and hlyA. The stx2 frequency was found to be higher than stx1 frequency. Also, it was observed that there was not any significant correlation between drug resistance profiles and presence of toxin genes in E.coli O157:H7 strains. As a result, increasing frequency of STEC O157 serotype among foodborne pathogens is a growing public health problem.

Isolation and characterization of avian influenza viruses from raw poultry products illegally imported to Japan by international flight passengers.

The transportation of poultry and related products for international trade contributes to transboundary pathogen spread and disease outbreaks worldwide. To prevent pathogen incursion through poultry products, many countries have regulations about animal health and poultry product quarantine. However, in Japan, animal products have been illegally introduced into the country in baggage and confiscated at the airport. Lately, the number of illegally imported poultry and the incursion risk of transboundary pathogens through poultry products have been increasing. In this study, we isolated avian influenza viruses (AIVs) from raw poultry products illegally imported to Japan by international passengers. Highly (H5N1 and H5N6) and low (H9N2 and H1N2) pathogenic AIVs were isolated from raw chicken and duck products carried by flight passengers. H5 and H9 isolates were phylogenetically closely related to viruses isolated from poultry in China, and haemagglutinin genes of H5N1 and H5N6 isolates belonged to clades 2.3.2.1c and 2.3.4.4, respectively. Experimental infections of H5 and H9 isolates in chickens and ducks demonstrated pathogenicity and tissue tropism to skeletal muscles. To prevent virus incursion by poultry products, it is important to encourage the phased cleaning based on the disease control and eradication and promote the reduction in contamination risk in animal products.

Characterization and Antimicrobial-Resistance Profile of Escherichia coli O157 and O157: H7 Isolated from Modified Atmosphere Packaged Meat Samples

Shiga-like toxin producing Escherichia coli is still an important public issue which causes extremely dangerous health problems. This study was planned in order to examine the inhibitory effect of Modified Atmosphere Packaging application on E. coli O157 and O157: H7. The purposes of the present study were to detect E. coli O157 and O157: H7 strains from ground and cubed beef. A total of 100 MAP cattle meat products (50 minced meat, 50 meat cubes) were collected from the markets and butchers in Samsun province between May and October 2013. According to results, 1(1/50-2%) E. coli O157 and 1(1/50-2%) E. coli O157: H7 strains isolated from 50 ground beef samples, while 1 (1/50-2%) E. coli O157 strain was identified from 50 cubed beef samples. It was determined that E. coli O157 isolate obtained from the MAP ground beef carried stx1, stx2 genes; E. coli O157: H7 isolate carried stx1, stx2, eaeA and hylA genes while E. coli O157 isolate obtained from the MAP cubed meat only carried the stx2 gene. In antibiogram test, both E. coli O157 isolates were resistant to streptomycin and one E. coli O157: H7 isolate was resistant to streptomycin, cephalothin and tetracycline. As a consequence; in order to protect public health, products should be kept in proper hygienic and technical conditions during sale and storage and use of uncontrolled antibiotics should be avoided.

Genome Sequences of 30 Escherichia coli O157:H7 Isolates Recovered from a Single Dairy Farm and Its Associated Off-Site Heifer-Raising Facility.

ABSTRACTCattle are the primary reservoir of Escherichia coli O157:H7, the most frequently isolated serotype of enterohemorrhagic E. coli infections among humans in North America. To evaluate the diversity of E. coli O157:H7 isolates within a single dairy herd, the genomes of 30 isolates collected over a 7-year period were sequenced.

Lineage-specific epitope profiles for HPAI H5 pre-pandemic vaccine selection and evaluation.

BackgroundMultiple highly pathogenic avian influenza (HPAI) H5 viruses continue to co‐circulate. This has complicated pandemic preparedness and confounded effective vaccine candidate selection and evaluation.ObjectivesIn this study, we aimed to predict and map the diversity of CD8+ T‐cell epitopes among H5 hemagglutinin (HA) gene lineages to estimate CD8+ T‐cell immunity in humans induced by vaccine candidates.MethodsA dataset consisting of 1125 H5 HA sequences collected between 1996 and 2017 from avian and humans was assembled for phylogenetic and lineage‐specific epitope analyses. Conserved epitopes were predicted from WHO‐endorsed vaccine candidates and representative clade‐defining strains by pairwise comparison with Immune Epitope Database (IEDB). The distribution of predicted epitopes was mapped to each HPAI H5 lineage. We assume that high similarity and conservancy of predicted epitopes from vaccine candidates among all circulating HPAI H5 lineages is correlated with high immunity.ResultsA total of 49 conserved CD8+ T‐cell epitopes were predicted at 28 different amino acid positions of the HA protein. Mapping these epitopes to the phylogenetic tree allowed us to develop epitope profiles, or “fingerprints,” for each HPAI H5 lineage. Vaccine epitope percentage analyses showed some epitope profiles were highly conserved for all H5 isolates and may be valuable for universal vaccine design. However, the positions with low coverage may explain why the vaccine candidates do not always function well.ConclusionsThese findings demonstrate that our analytical approach to evaluate conserved CD8+ T‐cell epitope prediction in a phylogenetic framework may provide important insights for computational design of vaccine selection and future epitope‐based design.

The genomic evolution of H1 influenza A viruses from swine detected in the United States between 2009 and 2016.

Transmission of influenza A virus (IAV) from humans to swine occurs with relative frequency and is a critical contributor to swine IAV diversity. Subsequent to the introduction of these human seasonal lineages, there is often reassortment with endemic viruses and antigenic drift. To address whether particular genome constellations contributed to viral persistence following the introduction of the 2009 H1N1 human pandemic virus to swine in the USA, we collated and analysed 616 whole genomes of swine H1 isolates. For each gene, sequences were aligned, the best-known maximum likelihood phylogeny was inferred, and each virus was assigned a clade based upon its evolutionary history. A time-scaled Bayesian approach was implemented for the haemagglutinin (HA) gene to determine the patterns of genetic diversity over time. From these analyses, we observed an increase in genome diversity across all H1 lineages and clades, with the H1-γ and H1-δ1 genetic clades containing the greatest number of unique genome patterns. We documented 74 genome patterns from 2009 to 2016, of which 3 genome patterns were consistently detected at a significantly higher level than others across the entire time period. Eight genome patterns increased significantly, while five genome patterns were shown to decline in detection over time. Viruses with genome patterns identified as persisting in the US swine population may possess a greater capacity to infect and transmit in swine. This study highlights the emerging genetic diversity of US swine IAV from 2009 to 2016, with implications for swine and public health and vaccine control efforts.

Molecular detection of Stx1 and Stx2 genes in E.Coli O157:H7 isolated from Cow's and Buffalo's soft cheese samples inBabylon Province, using Multiplex PCR technique.

Colonies of E.Coli O157:H7 were isolated from 80 locally produced Cow's and Buffalo's soft cheese samples that were collected randomly at weekly intervals (5 samples/ week) from various retail markets in different locations of babylon province during two climatic periods(40 samples /species/season) where the first periad was extended from the begining of December 2015 to the end of February 2016 while the second period was extended from the begining of July to the end of September 2016.The identification of E.Coli O157:H7 isolates were confirmed based on their cultural, biochemical and seralogical characteristics using the commercial latex agglutination test kit and by duplex PCR technique. Data revealed that there was a significant (P≤ 0.05) seasonal variation in the prevalence of E.Coli O157:H7 where all Cow's and Buffalo's soft cheese samples had significantly (P≤ 0.05) higher prevalence of E.Coli O157:H7 in summer season (50% and 40% respectively) than in winter season (25% and 15% respectively).It was found that all of the 80 bovine soft cheese samples had significantly (p&lt;0.05) higher prevalence of E.Coli O157:H7 in summer (45%) than in winter (20%) seasons.The results of the diagnosis of E.coli O157:H7 were confirmed by PCR assay which showed that,six culturing isolates serotype E.coli O157:H7 were postive by PCR assay and five of these isolates expressed gene of Stx1 whearse one isolate expressed gene of Stx2 .

Effect power levels in microwave of E.Coli O 157:H7 from bovine milk and Soft Cheese samples in Babylon Province

Colonies of E.Coli O157:H7 were isolated from 80 locally produced Cow's and Buffalo's soft cheese samples that were collected randomly at weekly intervals (5 samples/week) from various retail markets in different locations of babylon province during two climatic periods(40 samples /species/season) where the first periad was extended from the begining of December 2015 to the end of February 2016 while the second period was extended from the begining of July to the end of September 2016.In addition,50 fresh cattle faecal samples were collected from different farms in babylon province for the isolation of E.Coli O157:H7.The identification of E.Coli O157:H7 isolates were confirmed based on their cultural, biochemical and seralogical characteristics using the commercial latex agglutination test kit .Data revealed that there was a significant (P≤ 0.05) seasonal variation in the prevalence of E.Coli O157:H7 where all Cow's and Buffalo's soft cheese samples had significantly (P≤ 0.05) higher prevalence of E.Coli O157:H7 in summer season (50% and 40% respectively) than in winter season (25% and 15% respectively).It was found that all of the 80 bovine soft cheese samples had significantly (p≤0.05) higher prevalence of E.Coli O157:H7 in summer (45%) than in winter (20%) seasons.In addition to that, all the 50 bovine faecal samples had significantly (P≤ 0.05) higher prevalence of E.Coli O157:H7 in summer (72%) than in winter (40%) seasons. Complete elimination of viable E.Coli O157:H7 was achieved when the inoculated milk was subjected to the microwave power level of 900 watts after 30 seconds of exposure. Complete elimination of viable E.Coli O157:H7 was acheived when the contaminated soft cheese samples were subjected to the microwave power level of either 300 or 450 watts for 60 seconds of exposure.

Phenotypic and genotypic characterization of phosphate solubilizing bacteria and their efficiency on the growth of maize.

Phosphate solubilizing bacteria (PSB) has ability to convert insoluble form of phosphorous to an available form. Applications of PSB as inoculants increase the phosphorus uptake by plant in the agriculture field. In this study, isolation and identification of PSB were carried out in Indian agriculture field (Nainital region, Uttarakhand). A total of 8 phosphate solubilizing bacterial colonies were isolated on the Pikovskaya’s (PKV) agar medium, containing insoluble tricalcium phosphate (TCP). The colonies showed clear halo zones around the bacterial growth were considered as phosphate solubilizers. Out of 8 bacterial isolates, 3 isolates showed high phosphate solubilization index (PSI) ranged from 4.88 ± 0.69 to 4.48 ± 0.30, lower pH ranging 3.08 ± 0.08 to 3.82 ± 0.12 and high phosphate solubilization varied from 305.49 ± 10 μg/ml to 277.72 ± 1.45 μg/ml, were selected for further characterization. Based on the 16 S rRNA gene sequence analysis A4 isolate and H6 isolate were closely related to Alcaligenes aquatilis (99%), and C1 isolate was closely related to Burkholderia cepacia (99%). In addition, pot examination also showed the greatest efficiency in promotion of maize growth compared to uninoculated plant. Isolated PSB were able to produce different organic acids (such as gluconic acids, formic acid, and citric acid) in the culture supernatant and may consider as the principle mechanism for phosphate solubilization. This study clearly indicates that A4, C1 and H6 isolates may use as a biofertilizers in ecological agricultural systems instead of synthetic chemicals and may help to sustain environmental health and soil productivity.

Phenotypic identification of Escherichia coli O157:H7 isolates from cattle at Suleja Abattoir, Nigeria

Escherichia coli O157:H7 is a well-known pathogen of man and animals and a very low infection dose is needed to propagate the infection and clinical disease. In this study, a total of 515 rectal swab samples were collected from cattle and subjected to conventional biochemical tests. Presumptive identification on Eosine Methylene Blue (EMB) yielded an overall prevalence of 83.1%. Cefixime, Tallurite, Sorbitol MacConkey Agar (CT-SMAC) test yielded 18(4.2) isolates while Indole test, Methyl Red, Voges Proskauer and Citrate utilization test (IMVIC) biochemical test showed prevalence rate of 11(61.1%) and MicrogenTM test performed on the 18 Isolates yielded a prevalence rate of 33.3%. A total of 6 of the isolates were subjected to latex agglutination test, in which 2(0.4%) were confirmed to be E. coli O157. The results of the somatic flagella antigen test performed on the 2 isolates revealed that 1(50%) belonged to E. coli O157:H7. Thus this study is therefore the first research work to confirm the presence of E. coli O157:H7 in cattle presented for slaughter in Suleja abattoir in Nigeria. Humans can contract the infection through exposure, handling and consumption of beef or animal products. Control measures are therefore necessary especially during processing and evisceration of beef, to ensure safety of cattle offal presented to the public for human consumption. Key words: Escherichia coli O157:H7, cattle, Microgen kit, flagella staining, phenotypic identification, cattle, latex agglutination test.

Comparison of clinical and immunological findings in gnotobiotic piglets infected with Escherichia coli O104:H4 outbreak strain and EHEC O157:H7

BackgroundShiga toxin (Stx) producing Escherichia coli (E. coli) (STEC) is the most frequent cause of diarrhoea-positive haemolytic uraemic syndrome (D + HUS) in humans. In 2011, a huge outbreak with an STEC O104:H4 strain in Germany highlighted the limited possibilities for causative treatment of this syndrome. The responsible STEC strain was found to combine Stx production with adherence mechanisms normally found in enteroaggregative E. coli (EAEC). Pathotypes of E. coli evolve and can exhibit different adhesion mechanisms. It has been shown previously that neonatal gnotobiotic piglets are susceptible for infection with STEC, such as STEC O157:H7 as well as for EAEC, which are considered to be the phylogenetic origin of E. coli O104:H4. This study was designed to characterise the host response to infection with the STEC O104:H4 outbreak strain in comparison to an STEC O157:H7 isolate by evaluating clinical parameters (scoring) and markers of organ dysfunction (biochemistry), as well as immunological (flow cytometry, assessment of cytokines/chemokines and acute phase proteins) and histological alterations (light- and electron microscopy) in a gnotobiotic piglet model of haemolytic uraemic syndrome.ResultsWe observed severe clinical symptoms, such as diarrhoea, dehydration and neurological disorders as well as attaching-and-effacing lesions (A/E) in the colon in STEC O157:H7 infected piglets. In contrast, STEC O104:H4 challenged animals exhibited only mild clinical symptoms including diarrhoea and dehydration and HUS-specific/severe histopathological, haematological and biochemical alterations were only inconsistently presented by individual piglets. A specific adherence phenotype of STEC O104:H4 could not be observed. Flow cytometric analyses of lymphocytes derived from infected animals revealed an increase of natural killer cells (NK cells) during the course of infection revealing a potential role of this subset in the anti-bacterial activity in STEC disease.ConclusionsUnexpectedly, E. coli O104:H4 infection caused only mild symptoms and minor changes in histology and blood parameters in piglets. Outcome of the infection trial does not reflect E. coli O104:H4 associated human disease as observed during the outbreak in 2011. The potential role of cells of the innate immune system for STEC related disease pathogenesis should be further elucidated.

The recent emergence in hospitals of multidrug-resistant community-associated sequence type 1 and spa type t127 methicillin-resistant Staphylococcus aureus investigated by whole-genome sequencing: Implications for screening.

Community-associated spa type t127/t922 methicillin-resistant Staphylococcus aureus (MRSA) prevalence increased from 1%-7% in Ireland between 2010–2015. This study tracked the spread of 89 such isolates from June 2013-June 2016. These included 78 healthcare-associated and 11 community associated-MRSA isolates from a prolonged hospital outbreak (H1) (n = 46), 16 other hospitals (n = 28), four other healthcare facilities (n = 4) and community-associated sources (n = 11). Isolates underwent antimicrobial susceptibility testing, DNA microarray profiling and whole-genome sequencing. Minimum spanning trees were generated following core-genome multilocus sequence typing and pairwise single nucleotide variation (SNV) analysis was performed. All isolates were sequence type 1 MRSA staphylococcal cassette chromosome mec type IV (ST1-MRSA-IV) and 76/89 were multidrug-resistant. Fifty isolates, including 40/46 from H1, were high-level mupirocin-resistant, carrying a conjugative 39 kb iles2-encoding plasmid. Two closely related ST1-MRSA-IV strains (I and II) and multiple sporadic strains were identified. Strain I isolates (57/89), including 43/46 H1 and all high-level mupirocin-resistant isolates, exhibited ≤80 SNVs. Two strain I isolates from separate H1 healthcare workers differed from other H1/strain I isolates by 7–47 and 12–53 SNVs, respectively, indicating healthcare worker involvement in this outbreak. Strain II isolates (19/89), including the remaining H1 isolates, exhibited ≤127 SNVs. For each strain, the pairwise SNVs exhibited by healthcare-associated and community-associated isolates indicated recent transmission of ST1-MRSA-IV within and between multiple hospitals, healthcare facilities and communities in Ireland. Given the interchange between healthcare-associated and community-associated isolates in hospitals, the risk factors that inform screening for MRSA require revision.

Study the inhibitory effect of purified lipopolysaccharide extracted from Proteus mirabilis on E.coli O157 H7 isolate from diarrheal infected animals

Study the inhibitory effect of purified lipopolysaccharide extracted from Proteus mirabilis on E.coli O157 H7 isolate from diarrheal infected animals

H1N1 influenza viruses varying widely in hemagglutinin stability transmit efficiently from swine to swine and to ferrets.

A pandemic-capable influenza virus requires a hemagglutinin (HA) surface glycoprotein that is immunologically unseen by most people and is capable of supporting replication and transmission in humans. HA stabilization has been linked to 2009 pH1N1 pandemic potential in humans and H5N1 airborne transmissibility in the ferret model. Swine have served as an intermediate host for zoonotic influenza viruses, yet the evolutionary pressure exerted by this host on HA stability was unknown. For over 70 contemporary swine H1 and H3 isolates, we measured HA activation pH to range from pH 5.1 to 5.9 for H1 viruses and pH 5.3 to 5.8 for H3 viruses. Thus, contemporary swine isolates vary widely in HA stability, having values favored by both avian (pH >5.5) and human and ferret (pH ≤5.5) species. Using an early 2009 pandemic H1N1 (pH1N1) virus backbone, we generated three viruses differing by one HA residue that only altered HA stability: WT (pH 5.5), HA1-Y17H (pH 6.0), and HA2-R106K (pH 5.3). All three replicated in pigs and transmitted from pig-to-pig and pig-to-ferret. WT and R106 viruses maintained HA genotype and phenotype after transmission. Y17H (pH 6.0) acquired HA mutations that stabilized the HA protein to pH 5.8 after transmission to pigs and 5.5 after transmission to ferrets. Overall, we found swine support a broad range of HA activation pH for contact transmission and many recent swine H1N1 and H3N2 isolates have stabilized (human-like) HA proteins. This constitutes a heightened pandemic risk and underscores the importance of ongoing surveillance and control efforts for swine viruses.