- Volume 2, Issue 7A, 2020
Volume 2, Issue 7A, 2020
- Abstracts from Annual Conference 2020
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- Poster Presentation
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Effects of Vibrio cholerae infection and colonization on the zebrafish intestinal microbiome
More LessZebrafish (Danio rerio) are an attractive model organism for a variety of scientific studies, including host-microbe interactions. Zebrafish contain a core (i.e., consistently detected) intestinal microbiome consisting primarily of Proteobacteria. Furthermore, this core intestinal microbiome is plastic, and can be significantly altered to due external factors. The organism is particularly useful for the study of aquatic microbes that can colonize vertebrate hosts, including Vibrio cholerae. As an intestinal pathogen, V. cholerae needs to colonize the intestine of an exposed host for any type of pathogenicity to occur. It is suspected that members of the resident intestinal microbial community need to be eliminated by V. cholerae in order for colonization, and subsequently disease, to occur. While numerous studies have explored various aspects of the pathogenic effects of V. cholerae on zebrafish and other model organisms, few, if any, have examined how a V. cholerae infection alters the resident intestinal community. In this study, 16S rRNA gene sequencing was utilized to investigate how various strains of V. cholerae alter the aforementioned microbial profiles following an infection. We found that V. cholerae infection and subsequent colonization induced significant changes in the zebrafish intestinal microbiome, with specific members of the microbial community targeted. Additional salient differences to the microbial profile were observed based on the particular strain of V. cholerae utilized for challenging the zebrafish hosts. We conclude that V. cholerae causes significant modulation to the zebrafish intestinal microbiome in order for infection and subsequent disease to occur.
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Aeromonas caviae motility and glycosylation
More LessAeromonas are Gram-negative facultative anaerobic rods, which inhabit various aquatic environments and are pathogens of both warm and cold-blooded animals. In humans they cause gastro-enteritis and wound infections. They are motile in liquid environments by a single polar type of flagellum. The flagellum plays an important role for the bacterial colonisation and the adhesion to the host cells. The Aeromonaspolar flagella filament is a polymer composed of two flagellins, FlaA and FlaB. The flagellins are O-linked glycosylated through the addition of the unusual bacterial sugar pseudaminic acid to serine and threonine residues within the flagellins D2/D3 domain. The addition of this sugar is essential for flagella filament assembly and bacterial motility. The flagellin’s are modified by between 6 – 8 sugar residues that occupy the potential 14 sites of attachment. Motility accessory factors (Maf proteins) are candidate enzymes for transferring glycan molecules to the flagellin (glycosyltransferases transferring sugar to flagellin) due to their genetic location and motility phenotypes associated with disruption mutants.
This study utilised site-directed mutagenesis to change the potential sites of flagellin glycosylation to assess the effect of these mutations on motility by swimming assays and flagella filament formation by electron microscopy. The analysis of different numbers of site-directed mutants suggest that some sites are more important than others and that the removal of 4 sites results in greatly reduced motility.
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Antimicrobial resistance Salmonella isolates recovered from food products of animal origin in the Russian Federation
More LessThe study was aimed at Salmonella isolation from samples of animal food products submitted for testing from various regions of the Central part of the RF and serotyping of the recovered isolates and their testing for antibiotic resistance. A total of 2,342 tests were performed and 87 (3.7%) Salmonella isolates were recovered. Most of them (54 isolates) were recovered from poultry meat and poultry meat preparation samples submitted for testing. Besides, 25 isolates were recovered from pork and pork preparation samples, 7 isolates – from beef samples, 1 isolate – from hard cheese samples. Serotyping of 64 Salmonella isolates showed that the majority of the isolates (57.8%) belonged to О7 group. Also, Salmonella isolates belonging to О9 (21.9%), О8 (9.4%), О4,5 (6.2%) and О10 (4.7%) were detected in food products. S. Enteritidis, (23.3%), and S. infantis (18.7%), were predominant based on the number of detections. Also, the following serovars were identified: S. typhimurium, S. nigeria, S. montevideo, S. derby, S. meleagridis, S. virchov, S. oranienburg. Tests of 87 Salmonella isolates for their antibiotic resistance with disk diffusion method revealed that they were highly resistant to nalidixic acid (70.1%), tetracycline (49.4%), trimethoprim/sulfamethoxazol (40.2%). Moreover, nalidixic acid-resistance was common for all identified isolates. Seventeen isolates (19.5%) demonstrated multiple antibiotic resistance and two isolates were found to be resistant to ≥7 antibiotics. All recovered isolates were susceptible to gentamicin, amikacin, meropenem and imipenem. Obtained results indicate the necessity of Salmonella antibiotic resistance monitoring to gain understanding of Salmonellas’ antibiotic resistance emergence and trends.
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Bacterial profile of meconium of neonates born at National Referral Hospital Cipto Mangunkusumo, Jakarta, Indonesia
Microbial colonization of a neonate’s gastrointestinal tract has significant perinatal and lifetime health consequences, with some clinical outcomes that have been linked to differences in the diversity and composition of gut microbiota. The effort to engineer intestinal ecosystem has led us to preserve the cultivable commensal microbiota. Here we investigated the association of cultivable bacterial diversity of neonates meconium from Indonesian National Referral Hospital Cipto Mangunkusumo (NRHCM) with mode of delivery and feeding patterns, as well as hyperbilirubinemia. We performed a cross-sectional study of meconium and clinical data collected from 14 Indonesian neonates born at NRHCM. Culture-dependent identification of bacterial isolates was conducted by performing simultaneous microbiological and molecular 16S rDNA PCR-Sanger sequencing methods. Phylogenetic tree and principal components analysis were employed to determine the bacterial profile and their association with clinical characteristics and outcomes. Cultivable bacterial profile indicates the predominance of Firmicutes (84,41%), with an abundant population of Staphylococcus (53.24%) with top three most significant population present are, i.e. S. hominis (12.99%), S. epidermidis (11.68%), and S. haemolyticus (10.39%). Bacterial diversity was associated with mode of delivery which showed that vaginal route populated by lower diversity of cultivable bacteria but by fewer opportunistics one than that of cesarean, with Staphylococcus hominis dominates the population, whereas with feeding patterns showed that the exclusive breast-fed was most populated by Staphylococcus, whereas non-exclusive one shared the same proportion of Staphylococcus and Bacterioides. While, non-hyperbilirubinemia group showed more abundant and diverse Staphylococcus than that of the opposite group.
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A family of T6SS antibacterial effectors related to L,D-transpeptidases targets the Peptidoglycan
Type VI secretion systems (T6SSs) are contractile nanomachines widely used by bacteria to intoxicate competitors. Salmonella Typhimurium encodes a T6SS within the Salmonella pathogenicity island 6 (SPI-6) that is used during competition against species of the gut microbiota. We characterized a new SPI-6 T6SS antibacterial effector named Tlde1 (type VI L,D-transpeptidase effector 1). Tlde1 is toxic in target-cell periplasm and its toxicity is neutralized by co-expression with immunity protein Tldi1 (type VI L,D-transpeptidase immunity 1). Time-lapse microscopy revealed that intoxicated cells display altered cell division and lose cell envelope integrity. Bioinformatics analysis showed that Tlde1 is evolutionarily related to L,D-transpeptidases. Point mutations on conserved histidine121 and cysteine131 residues eliminated toxicity. Co-incubation of purified recombinant Tlde1 and peptidoglycan tetrapeptides showed that Tlde1 displays both L,D-carboxypeptidase activity by cleaving GM-tetrapeptides between meso-diaminopimelic acid3 and D-alanine4, and L,D-transpeptidase exchange activity by replacing D-alanine4 for a non-canonical D-amino acid. Tlde1 constitutes a new family of T6SS effectors widespread in Proteobacteria. This work increases our knowledge about the bacterial effectors used in interbacterial competitions and provides molecular insight into a new mechanism of bacterial antagonism.
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Assessment of mosquito insecticidal activity of bacterial extracts produced by Colombian strains
Aedes aegypti and Aedes albopictus are the major vectors for the transmission of more than 30 disease-causing viruses as dengue fever, dengue hemorragic fever, zika, yellow fever and chikungunya. Vector control is one of the important strategies used in order to fight these diseases in tropical and subtropical countries. However, mosquito control is facing a threat because of the emergence of resistance to synthetic insecticides. The aim of this study was to identify larvicidal and adulticidal activity of secondary metabolites in extracts produced by bacteria isolated from different sources in Colombia. A total of 105 extracts produced from the same number of bacteria were evaluated for their activity against fourth instar larvae and adults of A. aegypti and A. albopictus using standard protocols defined for the WHO (World Health Organization) and CDC (Control Disease Centre, USA). Six extracts showed relevant activity (more than 50% of mosquito larvae were killed after 48 hours), two of them showed to be actives against larvae of Aedes aegypti and four against larvae of Aedes albopictus. None of the extracts showed activity against the mosquitoes in adult stage. The bacteria producing active extracts were identified using the biolog ® identification system as Serratia marcescens ss marcescens, Escherichia hermannii, Serratia marcescens ss marcescens, Bacillus marisflavi, Bacillus atropheus/subtilis and Pseudomonas chlororaphis subsp. aurantiaca. In conclusion, bacterial extracts are a good source for the search of new strategies in the control of mosquitoes. Further studies to determine the compound responsible for the insecticidal activity are in progress.
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Screening for urinary tract infection-causing Klebsiella pneumoniae using CHROMagar
More LessIntroduction. Urinary tract infections (UTIs) are considered prevalent among humans. While Klebsiella pneumoniae and Escherichia coli are commonly isolated from patients with UTIs, K. pneumoniae is more frequently isolated from specimens isolated from hospital-acquired infections.
Aim. The current study aimed to characterise and evaluate pathogenic K. pneumoniae isolated from patients suspected with a UTI at King Abdulaziz University Hospital.
Methodology. Twenty-four urine samples obtained from patients, between 12 November 2018 and 11 January 2019, were included in the study, and the microbial content was analysed via urine culture and VITEK 2 analyses.
Results. Of the 24 urine specimens, 23 samples (95.8%) yielded significant microbial growth (> 105 CFU/mL K. pneumoniae), and one sample (4.2%) yielded non-pathogenic microbial growth (< 105 CFU/mL K. pneumoniae). Of the specimens with cell counts of >105 CFU/mL, 21 samples (87.5%) were pure cultures showing the growth of a single pathogen, and three samples (12.5%) were mixed cultures, showing the growth of two or more pathogens; 10 (41.7%) samples were extended-spectrum beta-lactamase (ESBL) producers. VITEK 2 analysis showed that the most effective antibiotic was piperacillin, with 87.5% of the strains isolated in this study showing sensitivity to it, followed by gentamicin (83.3%) and ciprofloxacin (79.2%). Antibiotic susceptibility studies identified resistance against ampicillin (45.83%), trimethoprim (41.67%), and amoxicillin (25%) in the study isolates. Differential chromogenic culture media CHROMagar ESBL and CHROMagar KPC (K. pneumoniae carbapenemase) were used for rapid screening of ESBL and KPC producers. Among the 24 K. pneumoniae isolates, six isolates (25%) formed metallic blue colonies on CHROMagar ESBL, five (20.3%) were inhibited, and nine (37.5%) showed weak pigmentation. Three isolates (12.5%) formed pink colonies on CHROMagar ESBL. Seventeen isolates (70.8%) were KPC-positive, four (16.7%) showed weak pigmentation, and three (12.5%) formed pink colonies on CHROMagar KPC. The results from CHROMagar cultures agreed with those of VITEK 2 analyses.
Conclusion. Various microbial detection methods have been used in medical microbiology laboratories to identify and screen for microbial resistance in clinical specimens. VITEK 2 and CHROMagar are amongst the commonly used methods. Here, we report a possible discrepancy between the detection techniques and that the data obtained by different methods need not be synergistic. However, the use of a chromogenic medium offers a quick and accurate method for detection, enumeration, and presumptive identification of urinary tract pathogens.
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Skin microbiome profiling and cultivation of healthy adult Indonesian skin
More LessStudies on the impact of skin microbiota on human health have been gaining more attention. The skin microbiome is considered to provide several probiotics for skin therapeutic. Beneficial bacteria mixtures (bacterial cocktail) isolated from targeted organs have shown promising modulatory activities for use in skin therapeutics. The objectives of this study were to determine and identify the microbial communities on the skin that can be potentially used as probiotics-postbiotics. Determination and identification of skin microbiota were carried out simultaneously by employing next-generation sequencing (NGS) of direct sampling, as well as by bacterial cultivation; twenty bacterial isolates with different characteristics were selected and identified by both culture-based methods and 16sRNA sequencing. We found that Actinobacteria and Firmicutes are the most abundant phylum present on the skin as presented by NGS data, which constitute to 67% and 28.59% of the whole bacterial population, consecutively. Three strains, i.e., Staphylococcus hominis (AN MK968325.1), Staphylococcus warneri (AN MK968315.1), and Micrococcus luteus (MK968318.1), were obtained from cultivable samples. They were potential to be developed further as probiotics in skin microbiome therapeutic as well as for postbiotic formulation. However, the promising formula of bacterial cocktail for skin microbiome therapeutic must be elucidated thoroughly to avoid unwanted effects by performing visual observation on agar plate and by molecular approach, q-PCR.
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Predominance of Streptococcus pneumoniae among TB patients complicates Dots chemotherapy at infectious diseases hospital Kano, Northwest Nigeria
More LessDirectly observed treatment Short course regimen has been know to be efficacious in the chemotherapy management of tuberculosis. However, co- infection with other opportunistic bacteria could limit this success to the level of clinical suspecting the emergence of false positive multidrugs resistant TB among the patients which in many cases can lead to establishment of erroneous treatment schedule. Accordingly this facility based surveillance monitors co-infection with other bacteria in TB patients attending Dots clinic at IDH Kano, Nigeria with view to ascertaining the drug susceptibility so as to proffer better chemotherapy strategies. A total 35 non - duplicated positive AFB sputum sample collected from patients with pulmonary tuberculosis on Dots where processed according to standard bacteriological procedures including macroscopic, culture and microscopic examination using both AFB gram staining and culture methods for screening and isolation of other bacterial pathogens. These were confirmed biochemically. Overall 54.3% of the patients were Still AFB positive, Streptococcus pneumoniae and Staphylococcus species we’re predominat in up to 84.2% and 15.8% of the patients respectively. This study indicated secondary bacterial pathogenesis with pulmonary symptoms resembling TB among the patients including those that were even isolated for being refrectory to Dots an false positive conclusion of drug resistant TB. However, ofloxacin and ceftriaxone which show appreciable potencies against secondary bacterial pathogens identified where used to treat successfully, patients claimed posses drug resistant TB. It’s imperative that, success of Dots therapy could be improved by augumentin with very potent non TB antibacterial such as Streptococcus pneumoniae regimen.
Keys. TB.
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Comprehensive evaluation of the antigenic impact of intra-genotypic human papillomavirus variant diversity on recognition by neutralizing monoclonal antibodies raised against lineage a L1 virus like particles
Introduction. Naturally-occurring variants of Human papillomavirus (HPV) genotypes have been defined as lineages and sub-lineages, but little is known about the impact of this diversity on protein function. We have previously demonstrated that variation within the major (L1) and minor (L2) capsid proteins impact the susceptibility of HPV to serum antibodies elicited by vaccination and natural infection. Higher resolution mapping of variant residues, however, requires the availability of appropriate tools, such as type-specific monoclonal antibodies (MAbs). These empirical data will improve our understanding of the consequences of natural variation on capsid antigenicity.
Methods. We investigated the susceptibility of 37 representative pseudovirus variants of HPV16, HPV18, HPV31, HPV33, HPV45, HPV52 and HPV58 to neutralization by type-specific murine MAbs raised against the A lineage of their respective genotypes. Homology models derived from available HPV L1 crystal structures were generated to permit mapping of variant residues onto the surface-exposed L1 protein for relevant variants
Results. Type-specific lineage A-specific MAbs demonstrated differential reactivity against some, but not all, variants within its respective genotype. Some of these differences were minor (<4 fold) while some variants displayed orders of magnitude reduced sensitivity. These differences in antigenicity were mapped to a limited number of variant residues on the capsid surface.
Conclusions. These data contribute to our understanding of HPV L1 variant antigenicity and may have implications for seroprevalence or vaccine immunity studies based upon L1 antigens.
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Molecular genetics of the virulence plasmids of pathogenic Escherichia coli O104:H4
More LessIn 2011 a large outbreak of enterohemorrhagic gastroenteritis and haemolytic uremic syndrome (HUS) throughout Europe resulted in almost 4,000 infections, 845 cases of HUS and 54 fatalities. This was due to a dangerous exchange of mobile genetic elements (MGE) resulting in a hybrid strain of E. coli O104:H4. This strain carried an unusual combination of EAEC- and STEC-associated virulence factors on a plasmid and phage respectively. In vitro the virulence plasmid has exhibited unusual stability under a wide range of environmental stresses, contrasting with rapid plasmid loss in the human gut. This project will characterise plasmid encoded maintenance systems responsible for its unique stability. Current investigations focus on toxin-antitoxin (TA) systems involved in postsegregationalkilling which contribute to plasmid maintenance therefore resulting in increased virulence. By inducing expression of putative TA genes cloned onto lab-made plasmid vectors, we have analysed their function in the cell. Once characterised we will further investigate the effects of various environmental conditions able to disrupt these TA systems, ultimately resulting in plasmid loss. This atypical strain displayed heightened pathogenicity and providedun foreseen treatment challenges. We aim to further our understanding of MGE carriage in O104:H4 as a model to predict and combat future outbreaks of hybrid pathovars.
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The Type VI secretion system in commensal Neisseria spp.
More LessA type 6 secretion system (T6SS) was recently identified in the genome sequence data of an isolate sourced from a throat swab of a volunteer that is believed to be N. subflava. The T6SS is one of the most recently discovered bacterial secretion systems and this is the first time it has been reported in Neisseriaceae. Since this discovery, genome sequence analyses for a number of other commensal Neisseria spp. has identified that in fact, two distinct T6SS types exist across Neisseriaceae. These two types are clearly defined and are different to one another in both their core gene sequences and organisation. The two systems also differ in the number of VgrG proteins required for toxic effector protein delivery, as well as type of effector associated with them. The predicted VgrG/effector combinations identified in our isolate are not common to all members of the same species and further analysis has identified a wide range of diversity in these components between different strains of the same species. The data provides possible evidence that T6SS positive commensal Neisseria spp. can acquire new VgrG/effector combinations through competitor killing. A number of putative effectors have so far been identified within the genome of our original isolate, including hydrolases, phospholipases, and nucleases. Whilst these are predicted to be antibacterial effectors, the conditions under which the T6SS system is activated, as well as demonstration of the function of the effectors still needs to be investigated experimentally.
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Failing to control Maedi-Visna
Maedi-Visna is a lentivirus of sheep that causes lung disease and chronic wasting. It has been designated an “Iceberg disease” by the UK sheep industry levy board with a very large burden of subclinical disease that is often not apparent until losses in an individual flock become catastrophic. Disease prevalence in the UK is thought to have doubled in the last 10 years, however farmer and veterinary awareness of the disease is poor. There is no vaccine and treatment is not cost effective, meaning that the only realistic control option is culling of affected animals.
Current testing protocols use MV gag protein ELISAs. A long lag time between infection and antibody production means that many animals are missed on flock screening and repeated rounds of testing over a period of years are necessary remove all infected animals. Preliminary testing of flocks that have attempted eradication indicates that those that do not keep testing until all animals are negative fail to eliminate the disease and that prevalence rates can even increase substantially in these flocks. The viruses extreme variability confounded attempts to develop a qPCR capable of detecting all variants, indeed deep sequencing was required to establish which strains of virus are currently present in UK sheep as there has been substantial genetic drift since the last sequencing studies (performed more than 20 years ago). More promisingly virus was detectable in nasal swabs of experimental animals at least offering a possibility for sampling methods that can be done by farmers themselves.
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Testing for novel inhibitors of periodontitis-associated sialidases
More LessThe microorganisms associated with severe periodontitis are the periodontal pathogens of the red complex: Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola. These organisms cleave sialic acids found at the terminal end of host glycoconjugates by hydrolysing the glycosidic linkages with their expressed sialidases, thereby affecting the integrity of the host periodontium and promoting disease progression. Both P. gingivalis (SiaPG) and T. forsythia (NanH) sialidase enzymes were purified using HisTag affinity chromatography and a range of putative synthetic and plant-based inhibitors were tested for their ability to inhibit both enzymes using a MUNANA cleavage assay. Investigation of sialidase inhibitory activity of these compounds revealed that the plant derived alkaloids: Epicatechin gallate (IC50 = 21.75μM and 120.9μM) and Berberine chloride (IC50 = 106.2μM and 125.5μM) were more effective inhibitors of both SiaPg and NanH enzymes than the anti-influenza drug Zanamivir, an FDA approved viral neuraminidase inhibitor. Finally, a range of newly synthesized sialic acid analogues were effective in the micromolar to nanomolar range against both SiaPg and NanH enzymes with compound 2e3aDFNeu5Ac9N3 having an IC50 of (3.846μM and 49.40nM) respectively. The data suggests several novel inhibitors of these enzymes that might have future use as novel drugs against diseases such as periodontitis, and which we are currently testing further in host-pathogen interaction studies.
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Coccus Pocus 2019: A microbiology-inspired scary story competition
More LessAntibiotic resistance by pathogenic microorganisms is a major threat of our times, leading to a significant rise of serious untreatable infections, especially in hospital environments. In addition, biofilms further protect the microbes against antibiotics, detergents and the attacks of our immune system. This Halloween, we launched an exciting scary story competition, named Coccus Pocus 2019. The participants were encouraged to write a short horror sci-fi story between 500 and 2,000 words, including antimicrobial resistance and microbial biofilms. The evaluation committee that was composed of eight academics and researchers from the University of Hull and other institutions, ranked the stories according to intrigue of their plot, use of language, character description and scientific soundness. The prizes (online gift vouchers) were awarded to the three winning stories, during an awards ceremony. Feedback questionnaires were completed by the participants, which showed that they all found the competition very interesting and useful, allowing them to sharpen their creative writing skills and explore key microbiology topics. The event was communicated in the social media and blogs were posted in university bulletins and on microbiology websites. It is our ambition that the competition will be held again and again around the country, aiming to increase public awareness about the important problem of antimicrobial resistance and biofilms and boost the enthusiasm of young people about the fascinating field of microbiology.
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Intelligent wound dressing for diagnostic & therapeutic applications - critical to wound infection
More LessA medical device comprising of biomaterials responsive to biochemical stimuli: channel for indicating the infective states of wounds and ensuring delivery of smart antimicrobial and antibiofilm agents to promote tissue regeneration and healing.
The importance of providing diagnostic wound dressings that can inform healthcare professionals on the state of infection within wounds but also provide some of the treatment required in response to at risk or infected wounds is of key interest. The aim is to investigate an innovative proof of concept diagnostic and detection system, an intelligent hydrogel wound dressing that responds to specific biochemical stimuli in wounds (MMPs and pH) enabling the selective and triggered release of antibiofilm and antimicrobial agents (‘Detect and Treat’)to the trauma site. The dressing is made of a sterile alginate core material covered in a biocompatible dry or hydrated peptide-polymer-complex film and may include a fluorescent dye which upon release during the wound healing process indicates when a change in dressing is necessary. Efficacy studies of the hydrogel dressing were performed within a drip-flow bioreactor in which regression of Pseudomonas aeruginosa biofilm was observed. A 5-log reduction in biofilm was observed in comparison to an untreated control biofilm. The hydrogel dressing indicated a clear response when in contact with biofilms produced only by pathogenic strains of bacteria when analysed. This further confirmed the adequate release and function of the antimicrobial and antibiofilm agents within the peptide-polymer-complex formulation of the hydrogel wound dressing.
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Epidemiological studies of malaria parasite on HIV patients attending General Hospital Awo-Omamma, Oru East, Imo State,Nigeria
More LessHIV and malaria are the two most prevalent and deadly diseases in the world. Malaria and HIV accounted for about 255 million cases in 2017, with malaria having 86% of this distribution and HIV having 14% of the distribution. Given the overlap of their geographic distribution and resultant rates of coinfection, interactions between the two diseases pose major public health problems. This study was aimed at investigating the epidemiology of malaria –HIV co-infection in respect to sex, age and its association with CD4+ count and viral load. 230 HIV sero-positive participants and 100 HIV sero-negative participants(control) were employed for this study. 52 (22.6%) of the HIV infected participants tested positive for malaria while only 9(9.0%) of the non-HIV participants tested positive to malaria. The prevalence of malarial infection in HIV positive individuals was higher in females (23.9%) than in males (18.5%). While in age group of 30-39 showed the highest prevalence (35.3%) of co-infection. A high prevalence of 47.7% was recorded with CD4+ below 200 cells/μl than 7.6% in participants with CD4+ greater than 200 cells/μl. A highprevalence (49.2%) was also detected in patients with viral load of above 10,000 copies/μl compared to that of those with viral load less than 10,000 copies/μl(12.6%). This study showed a high prevalence of malaria in HIV patients in Awo-Omamma,Oru East, Imo state. This should be considered a great concern to public health. Thus, more effort should be put in research to curb this health issue.
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An investigation into extended spectrum beta-lactamase colonisation in travellers to Laos
More LessIncreased frequency of global travel has facilitated the spread of antimicrobial resistant organisms like extended spectrum β-lactamase (ESBL)- producing organisms and carbapenamase-producing Enterobacteriaceae through increased exposure and transient or persistent colonisation. This study investigates the impact of travel to Laos and of faecal colonisation with ESBLs aiming to help understand the diversity of organisms and also persistency of antimicrobial resistance (AMR) during the study and on return.
Daily faecal samples were collected from 23 doctors visiting Laos over a 21-day period which allowed detection of both constant colonisation and changes to the bowel colonisation over time. Bioinformatic techniques were used to identify ESBL-producing isolates obtained from participants and their contacts. Isolates were sequenced, assembled and annotated. SNP analysis was performed and phylogenetic trees constructed using the core SNP alignment. Escherichia coli was the most prevalent species with a highly diverse array of sequence types. Citrobacter and Klebsiella were the most abundant non-E. coli species. This study confirmed that Laos is an area with high levels of AMR with 28% isolates found to have mobile colistin resistance. There was also a highly diverse and extensive spread of unexpected blaCTX-M genes. Prolonged persistence of resistance genes in the three most prevalent study species found after travellers returned is another serious cause for concern emphasising the extended risk of spread of AMR from high risk to low risk countries. Future work will allow exploration of possible AMR transmission and horizontal transfer of resistance between isolates.
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Defining the RND-binding residues of AcrA
More LessThe resistance-nodulation-division (RND) family of efflux pumps confer clinically relevant antibiotic resistance in Gram-negative bacteria, such as Salmonella enterica. RND pumps, including AcrB, are organized as tri-partite systems, consisting of an inner membrane RND pump, a periplasmic adaptor protein (PAP) and an outer membrane channel. Previously, inactivation of the PAPs AcrA and AcrE in S. enterica has been shown to significantly increase susceptibility to antimicrobials and reduce virulence. Therefore, PAPs are seen as attractive targets for the development of efflux pump inhibitors. However, the role of PAPs in the assembly of tri-partite pumps and the residues involved in PAP-RND pump binding is poorly understood. In this study, point mutations in the predicted RND binding residues of AcrA were generated by site-directed mutagenesis. The point mutants were characterised phenotypically through ethidium bromide efflux assays and antimicrobial susceptibility testing. Furthermore, Western blotting was used to verify that the phenotypic effect of the point mutations was not due to destabilisation of the AcrA protein. Point mutations in certain residues, such as G58, F292, R294 and G363 were found to significantly impair efflux activity and increase susceptibility to various antibiotics and dyes, suggesting an important role for these AcrA residues in RND pump binding. Western blotting confirmed that these point mutants were stable and exhibited similar expression levels to the wild-type. These residues could be important targets for the design and development of PAP inhibitors to restore the activity of existing antibiotics and reduce virulence of Salmonella.
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Food safety knowledge and hygiene practices among the staff of school feeding scheme in the basic schools of Sewoto, South Africa
More LessThe study was to evaluate the food safety knowledge and hygiene practices of the staff of the school feeding scheme in Soweto. A total of 42 food handlers in 13 basic schools under the School Feeding Scheme, Soweto, South Africa were recruited for the study using purposive and convenience sampling methods for the respondents and institutions respectively. A piloted self-administered questionnaire was used. All the respondents were female (100%) with majority being between the ages of 31 and 40 (40%) and had secondary education (63%). About 38 (90.5%) of the respondents indicated that food safety is important, hence, identified “promotion of good health 41 (97.6%), avoidance of bacterial infection 39 (92.9%) and prevention of food poisoning 39 (92.9)” as the major importance. Frequent hand washing 40 (95.2%); cleaning and sanitizing knives/cutting boards 40 (95.3%); checking best before date 39 (92.8); keeping kitchen surfaces clean (80.9%) and checking freshness/appearance of the food upon delivery (88.1%) were indicated as very important food safety and hygiene practices. However, they failed to agree that frozen foods, particularly meat are to be thawed using room temperature (4.8%) and also in the lower shelf in the refrigerators (26.2%) as the best practices. Spearman’s correlation coefficient revealed that no correlation exists between food safety knowledge and hygiene practices. However, there was strong positive correlations among educational level, knowledge and practices (P>0.05). Eventhough they have good knowledge and understanding of food safety issues, they still need training and workshops particularly in HACCP to cover-up the lapses.
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Prevalence and resistance pattern of uropathogens from community settings of different regions: an experience from India
Sarita Mohapatra, Rajashree Panigrahy, Vibhor Tak, Shwetha J. V., Sneha K. C., Susmita Chaudhuri, Swati Pundir, Deepak Kocher, Hitender Gautam, Seema Sood, Bimal Kumar Das, Arti Kapil, Pankaj Hari, Arvind Kumar, Rajesh Kumari, Mani Kalaivani, Ambica R., Harshal Ramesh Salve, Sumit Malhotra and Shashi Kant
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