Greater Number Of Isolates Research Articles

Assessment of Fungal Contamination and Their Toxigenic Potential of Farmed Fish in Western Algeria

Fish and fish products have been documented as a major source of pathogens, with fungi playing a key role. In this paper, a survey was conducted to determine the presence of fungi in fish reared in various aquaculture farms in western Algeria, namely Nile Tilapia (Oreochromis niloticus), gilthead sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax). The search for micromycetes was carried out on different parts of the body: skin and flesh, gills, and intestines. A total of 1937 fungal strains were revealed and divided into 10 genera of filamentous fungi, one genus of yeast, and other yeasts that have not yet been determined. Penicillium was the most common genus, representing 41.56% of the fungal population, fol-lowed by Rhodotorula (17.60%), and Aspergillus (15.95%). The greatest number of isolates was identified in the gills of gilthead sea bream, while the lowest number was isolated from sea bass intestines. Secondly, we sought to highlight the toxigenic potential of the fungal strains isolated, using the brine shrimp lethality test. Five of the fungal strains tested, belonging to the two genera Penicillium and Aspergillus, showed toxic potential for Artemia salina. The highest toxicities were observed mainly by strains of Aspergillus parasiticus (APAR001), Aspergillus terreus (ATER002), and Aspergillus niger (ANIG001) respectively. Penicillium chrysogenum (PCHR002) showed the lowest activity. These results confirm the infection of farmed fish by toxigenic fungal communities, which can present a real health hazard to consumers. Regular monitoring and compliance with fish health management practices are recommended.

(419) In Vivo Next Generation Sequencing Identifies More Isolates vs. Standard Culture During Revision Inflatable Penile Prosthesis Insertion: A Single Center Experience

Abstract Introduction The presence of biofilm at the inflatable penile prosthesis (IPP) component sites, which resists eradication, likely increases postoperative infection rates in revision surgery. The microbiome of (IPP) revision surgery has been shown to be increasingly complex and the weak microbe Staph epidermidis is no longer prevailing and was previously considered the major causative agent for overt infections. Furthermore, next generation sequencing (MicrogenDx, Lubbock, TX, USA) has been used recently to demonstrate that in certain scenarios such as mechanical malfunction, erosion, and infection, specific microbes dominate. Due to the disastrous complications with postoperative IPP infection, it is paramount to provide additional evidence for increased utilization of next generation sequencing over traditional cultures during IPP revision surgery. This will serve to guide postoperative treatment if necessary. Objective We investigated a cohort of IPP revision patients receiving intraoperative low concentration chlorhexidine (CHG) lavage to see whether next generation sequencing or traditional cultures of the pump space reveals more isolates. Methods A total of 31 patients with indwelling IPPs underwent revision surgery for both infectious and noninfectious reasons between May 2021 and March 2022 by a single, high volume implant surgeon who solely uses 0.05% CHG dip and irrigation. Once the pump capsule was entered, swabs were taken from the pump space and sent for traditional culture and next generation sequencing. All cultures were obtained prior to irrigation with 0.05% chlorhexidine (CHG) solution (Irrimax corporation, Lawrenceville, GA, USA). All patients received perioperative clindamycin, gentamicin, and fluconazole. Results 1 patient was excluded due to missing next generation sequencing results. Of the 30 remaining patients, 4 presented with infectious and 26 with noninfectious etiologies. 93% (28/30) patients had negative traditional cultures prior to irrigation with 0.05% CHG; however, 21% (6/28) of these patients had isolates on next generation sequencing. Only 7% (2/30) had positive preop irrigation cultures and isolates on next generation sequencing. Both of these patients presented with infection. 1 of these patients had a concordant next generation sequencing result. However, the other patient had multiple isolates. The traditional culture showed only pseudomonas a. On NGS, it was the third most abundant on NGS at only 4% compared to the most and second most abundant being E. coli at 83% and Klebsiella p. at 12%. Conclusions These results suggests that a greater number of isolates are obtained using next generation sequencing compared to traditional cultures during IPP revision surgery. Consequently, this may lead to better prevention and/or better guide treatment of postoperative IPP infection in the setting of IPP replacement. Although, further studies are needed prior to universally adopting this modality. Disclosure Yes, this is sponsored by industry/sponsor: MicrogenDx. Clarification Industry funding only - investigator initiated and executed study. Any of the authors act as a consultant, employee or shareholder of an industry for: MicrogenDx.

Seed endophytic bacterial profiling from wheat varieties of contrasting heat sensitivity.

Wheat yield can be limited by many biotic and abiotic factors. Heat stress at the grain filling stage is a factor that reduces wheat production tremendously. The potential role of endophytic microorganisms in mitigating plant stress through various biomolecules like enzymes and growth hormones and also by improving plant nutrition has led to a more in-depth exploration of the plant microbiome for such functions. Hence, we devised this study to investigate the abundance and diversity of wheat seed endophytic bacteria (WSEB) from heatS (heat susceptible, GW322) and heatT (heat tolerant, HD3298 and HD3271) varieties by culturable and unculturable approaches. The results evidenced that the culturable diversity was higher in the heatS variety than in the heatT variety and Bacillus was found to be dominant among the 10 different bacterial genera identified. Though the WSEB population was higher in the heatS variety, a greater number of isolates from the heatT variety showed tolerance to higher temperatures (up to 55°C) along with PGP activities such as indole acetic acid (IAA) production and nutrient acquisition. Additionally, the metagenomic analysis of seed microbiota unveiled higher bacterial diversity, with a predominance of the phyla Proteobacteria covering >50% of OTUs, followed by Firmicutes and Actinobacteria. There were considerable variations in the abundance and diversity between heat sensitivity contrasting varieties, where notably more thermophilic bacterial OTUs were observed in the heatT samples, which could be attributed to conferring tolerance against heat stress. Furthermore, exploring the functional characteristics of culturable and unculturable microbiomes would provide more comprehensive information on improving plant growth and productivity for sustainable agriculture.

Diversity of root endophytic bacteria from maize seedling involved in biocontrol and plant growth promotion

BackgroundNative endophytes from maize could play a vital role in plant protection and growth promotion. The present study was undertaken to elucidate the effect of soil types and different maize varieties on culturable endophytic bacterial diversity and to use potential endophytes as biocontrol agents and plant growth promoters.ResultsBased on rpoB and 16S rRNA genes, one hundred seventy-four (174) endophytes distributed into twenty-five (25) genera were identified, in which the greatest number of isolates were classified into Bacillus (52.30%), followed by Streptomyces (13.22%), Paenibacillus (6.32%), and Pseudomonas (4.60%). Out of the total isolated strains, endophytic strains with total number thirteen (13), eighty-four (84), one hundred and five (105), and nine (9) were able to fix nitrogen, and solubilize calcium phosphate, calcium phytate, and potassium, respectively. Moreover, out of total endophytes; twenty-four (24), thirty-three (33) and twenty-one (21) endophytic strains displayed marked antagonistic effects against important fungal pathogens such as Fusarium graminearum, Rhizoctonia solani and Exserohilum turcicum, respectively.ConclusionsSoil types play a functional role in culturable endophyte diversity and provide an isolation reference for endophytic reserves with multiple functions such as growth promoters and biocontrol agents.

Microbiota of diabetic foot infections in a University Hospital in Bogotá, Colombia

The presence of infection in diabetic foot ulcers (DFU) is one of the main causes of lower limb amputation in the world. The presence of polymicrobial infections is usually the standard for isolation in such lesions, with Gram Positive (GP) germs being the main organisms involved, as is described in the global literature. However, some studies indicate a greater number of isolates with Gram Negative (GN) germs, reported mainly in the literature of Middle Eastern countries and in the tropics.

In Vitro Activity of Minocycline Against Multidrug-Resistant Acinetobacter baumannii Isolates-Evaluation of Clinical Breakpoints and Review of Literature.

Therapeutic options for the treatment of infections by multidrug-resistant Acinetobacter baumannii strains are often limited. Minocycline (MIN) is an old antibiotic, with excellent activity against A. baumannii isolates, which can be administered orally. Currently, there is no single criterion regarding the breakpoints for MIN and A. baumannii. The activity of MIN was examined against a collection of A. baumannii isolates recovered from 15 hospitals of 6 countries of South America. A review of the literature was also performed. In our series and most of the studies, the percentages of MIN susceptible isolates exceeded 50%, regardless of the breakpoints utilized (4-2 or 1 μg/mL). However, a greater number of isolates not harboring Tet B were considered resistant with the breakpoints of 1 or 2 μg/mL, whereas isolates with tet(B) genes were still detected with minimum inhibitory concentration below all breakpoints considered. Tetracycline susceptibility may be used as a screening to discriminate the populations with and without acquired resistance mechanisms to MIN. In this study, MIN-resistant subpopulations were found in isolates harboring Tet B, with MIC ≤1 μg/mL, and their frequency increased after incubation with MIN. These subpopulations were not detected in isolates not harboring Tet B. The clinical correlation of these subpopulations should be evaluated in future studies.

Agarda Dilüsyon ve Deneme Aşamasındaki EUCAST Disk Difüzyon Yöntemi ile Saptanan Bacteroides fragilis Grubu İzolatlarına Ait Antimikrobiyal Duyarlılık Sonuçlarının Karşılaştırılması

Objective: In this study it was aimed to determine the antimicrobial susceptibility of Bacteroides fragilis group (BFG) bacteria using recently developed European Committee on Antimicrobial Susceptibility Testing (EUCAST) disc diffusion method and agar dilution method recommended by Clinical Laboratory Standart Institude (CLSI) for anaerobes and to investigate the agreement of the results of two tests. Method: The antimicrobial susceptibilities of a total of 56 BFG strains isolated from clinical samples and identified by MALDI-TOF MS analysis between January 2017 and December 2018, were tested to ampicillin, ampicillin/sulbactam, cefoxitin, imipenem, clindamycin, tigecycline, moxifloxacin and metronidazole MICs were determined by agar dilution method using sheep blood supplemented Brucella agar and disk diffusion test using host blood supplemented Fastidius Anaerobic Agar (FAA). Results: Six different BFG species consisting mostly strains of Bacteroides fragilis (n=34, 61%) and Bacteroides thetaiotaomicron (n=11, 20%) isolated from various clinical samples such as intraabdominal abscess (n= 24), blood (n=10) and tissue biopsy samples (n=11).were identified. Imipenem and metronidazole were the most effective antimicrobials with 98.2% susceptibility rates, followed by tigecycline, ampicillin/sulbactam, moxifloxacin and clindamycin with susceptibility rates of 89.3%, 66.1%, 57.1% and 46.4%, respectively. Most concordant results were obtained with metronidazole (100%), imipenem (89.8%) and tigecycline (89.8%). Acceptable compliance rates were not found for other antimicrobials. Conclusion: We can say that disc diffusion method is a fast, easy-to-apply, and reliable method used in clinical microbiology laboratories to determine the susceptibility of BFG bacteria to metronidazole, imipenem and tigecycline. However, to evolve a standard method especially for other antimicrobials, the experimental conditions should be optimized with studies dome with greater number of isolates.

Characterization of cultivable endophytic fungi from the medicinal plant Senna reticulata (Willd.) H. S. Irwin & Barneby

The objective of this work was to characterize the endophytic fungi community of the medicinal plant S. reticulata. Vegetable tissue samples from S. reticulata plants, stems and leaves, were collected, washed and disinfected by immersion in 70% etanol, 2% sodium hypochlorite, 70% alcohol, and washing in sterile distilled water. The samples were fragmented and inoculated in PDA and Sabouraud culture media, with and without plant extract. After inoculation, the plates were incubated at 18 ºC or 28 ºC for 30 days. The isolated fungi were characterized in terms of their macromorphology and micromorphology. A total of 309 S. reticulata endophytic fungi, 178 stem fungi and 131 leaf fungi, were isolated. A greater number of isolates was obtained in plant I, totaling 194. Sabouraud medium with plant extract at 18 oC, were the best conditions for isolation of endophytic fungi of S. reticulata. 27 morphospecies were identified, distributed in ten genera, Phomopsis (32.4%), Penicillium (13%), Aspergillus (5.8%), Acremonium (2.6%), Colletotrichum (1.6%), Curvularia (1.6%), Alternaria (0.3%), Trichoderma (0.3%), Cladosporium (0.3%) and Xylaria (0.3%). Senna reticulata has a diverse community of endophytic fungi, with Phomopsis as dominant. This is the first report of endophytic fungi from the medicinal plant Senna reticulata.   Keywords: Pasture killer; Medicinal plants; Phomopsis.

Staphylococcal species less frequently isolated from human clinical specimens - are they a threat for hospital patients?

BackgroundCoagulase-negative staphylococci belonging to S. haemolyticus, S. hominis subsp. hominis, S. simulans, and S. warneri are often described as etiological factors of infections. Staphylococci are a phylogenetically coherent group; nevertheless, there are differences among the species which may be important to clinicians.MethodsWe investigated selected virulence factors and antibiotic resistance that were phenotypically demonstrated, the presence and expression of genes encoding the virulence factors, and the type of the SCCmec cassette.ResultsThe differences between the tested species were revealed. A great number of isolates produced a biofilm and many of them contained single icaADBC operon genes. Clear differences between species in the lipolytic activity spectrum could be related to their ability to cause various types of infections. Our studies also revealed the presence of genes encoding virulence factors homologous to S. aureus in the analysed species such as enterotoxin and pvl genes, which were also expressed in single isolates of S. simulans and S. warneri. S. haemolyticus and S. hominis subsp. hominis isolates were resistant to all clinically important antibiotics including ß-lactams. The identified SCCmec cassettes belonged to IV, V, VII, and IX type but most of the detected cassettes were non-typeable. Among the investigated species, S. hominis subsp. hominis isolates accumulated virulence genes typical for S. aureus in the most efficient way and were widely resistant to antibiotics.ConclusionsOur results clearly indicated significant differences between the tested species, which might be a result of the horizontal gene transfer (HGT) and can lead to the formation and selection of multi-drug resistant strains as well as strains with new virulence features. Such strains can have a new clinical relevance.

Campylobacter coli in Swine Slaughtering Flowchart and Research of cdt Genes

Background: Campylobacter spp. are among the microorganisms most commonly associated with foodborne disease. Campylobacter spp. isolation from pigs during the slaughter and final products have been reported in several countries, including Brazil. However, very little is known about the sources of contamination in the slaughtering flowchart and how these microorganisms are spread in processing plants. Considering the possibility of the pigs carry Campylobacter spp. since the farm or its products are contaminated in the slaughterhouse, this study had as aim to track Campylobacter spp. in pig slaughtering flowchart to understand the behavior of these pathogens in the production line.Materials, Methods & Results: Forty animals of 10 lots, four from each lot, were followed during slaughter. Stool samples were collected from the floor of each enclosure where the pigs were housed on the farm and immediately after stunning on slaughterhouse. Samples from carcass surface were collected after removal of the animals from scrap machine, after evisceration and before the refrigeration chamber. It was also collected surface samples from jowls and samples from the scalding tank water before and after the passage of animals. The swabs containing samples were plated onto Columbia agar supplemented with activated charcoal, oxygen reduction solution and antibiotics supplement, and incubated at 42°C for 48 h under microaerobic conditions. The colonies which presented with a shiny and moist appearance were analyzed by Gram staining for identification of Campylobacter by morphology, and then tested for catalase and oxidase. The Campylobacter isolates were identified for species C. jejuni or C. coli by PCR. Bands profiles were determined by rep-PCR and used to compare the strains. Campylobacter was isolated from 19 (9.5%) of the 200 pig samples analyzed, seven (36.8%) of the rectum, seven (36.8%) after evisceration and five (26.3%) before the refrigeration chamber. Campylobacter was not isolated from jowls and from scalding tank water. All isolates were C. coliand cdtnegative.Persistence of strains originating from the farm and cross contaminations during the slaughtering flowchart was identified by the analysis of the bands profiles obtained by rep-PCR.Discussion: C. coli was the species of Campylobacter present in the swine intestinal tract and in the swine slaughterhouse. The animals, once contaminated, can carry the microorganism during the stages of the slaughtering flowchart. The farm where the animals came from is an important source of contamination during processing, however cross contamination also plays a relevant role. The evisceration was considered the most critical stage, due to the greater number of isolates obtained after this procedure, what emphasize the importance of the hygienic-sanitary management in this stage. Campylobacter spp. can survive, despite not being able to multiply, in foods at refrigeration temperatures (-1 to 5°C) for one to three weeks. Therefore, the high percentage of isolates obtained from the carcass before the refrigeration chamber may represent a problem, since the contamination of the carcasses that enter in this sector can be maintained until the food reaches the consumer. There was no similarity between strains isolated from different lots, indicating that there were no persistence of strains both in the farm and in the slaughterhouse.

Mycological Profile of the Integumentary System in Felin Ponies

Abstract Yeast-like microorganisms are frequently isolated from horses. There is a serious interpretation problem with assessment of the health status in the diagnostics of infectious diseases, which is associated with the insufficient knowledge of the composition of the natural flora in the horses’ integumentary system. The aim of the investigations was to analyse the yeast-like flora isolated from healthy Felin ponies. The study involved 44 horses aged from 2 to 12 years. The analysed group comprised 28 mares and 16 stallions. The animals were kept in an outdoor rearing system with a possibility of periodic use of a wooden/brick shed. The investigations were conducted in an annual cycle divided into 4 periods corresponding to the seasons of the year. Smears were sampled from horses’ nostrils, mouth, ear, back, groin, vagina or foreskin, and collateral groove. Microbiological analysis of the yeast-like strains was performed after plating 1015 samples of material taken from healthy horses. The identification of fungal species was based on their culture characteristics and biochemical profile. Fourteen yeast species were isolated and identified from the sampled material. Candida guilliermondii and Candida albicans 1 were the most prevalent fungi. The study has shown seasonal variability of the composition of the integumentary system microflora in Felin ponies. The greatest number of isolates was obtained from the material sampled from the mouth.

Phytophthora species recovered from the Connecticut River Valley in Massachusetts, USA

Little is currently known about the assemblage of Phytophthora species in northeastern North America, representing a gap in our understanding of species incidence. Therefore, Phytophthora species were surveyed at 20 sites in Massachusetts, with 16 occurring in the Connecticut River Valley. Many of the sampled waterways were adjacent to active agricultural lands, yet were buffered by mature floodplain forests composed of Acer, Platanus, Populus and Ulmus. Isolates were recovered with three types of baits (rhododendron leaves, pear, green pepper) in 2013 and water filtration in 2014. Overall, 457 isolates of Phytophthora were recovered and based on morphological characters and rDNA internal transcribed spacer (ITS), β-tubulin (β-tub) and cytochrome oxidase c subunit I (cox1) sequences, 18 taxa were identified, including three new species: P. taxon intercalaris, P. taxon caryae and P. taxon pocumtuck. In addition, 49 isolates representing five species of Phytopythium also were identified. Water filtration captured a greater number of taxa (18) compared to leaf and fruit baits (12). Of the three bait types rhododendron leaves yielded the greatest number of isolates and taxa, followed by pear and green pepper, respectively. Despite the proximity to agricultural lands, none of the Phytophthora species baited are considered serious pathogens of vegetable crops in the region. However, many of the recovered species are known woody plant pathogens, including four species in the P. citricola s.l. complex that were identified: P. plurivora, P. citricola III, P. pini and a putative novel species, referred to here as P. taxon caryae. An additional novel species, P. taxon pocumtuck, is a close relative of P. borealis based on cox1 sequences. The results illustrate a high level of Phytophthora species richness in the Connecticut River Valley and that major rivers can serve as a source of inoculum for pathogenic Phytophthora species in the northeast.

Personal Network Structure and Substance Use in Women by 12 Months Post Treatment Intake

IntroductionWomen with substance use disorders enter treatment with limited personal network resources and reduced recovery support. This study examined the impact of personal networks on substance use by 12months post treatment intake. MethodsData were collected from 284 women who received substance abuse treatment. At 6month follow up, composition, support availability and structure of personal networks were examined. Substance use was measured by women's report of any use of alcohol or drugs. Hierarchical multivariate logistic regression was conducted to examine the contribution of personal network characteristics on substance use by 12months post treatment intake. ResultsHigher numbers of substance using alters (network members) and more densely connected networks at 6month follow-up were associated with an increased likelihood of substance use by 12months post treatment intake. A greater number of isolates in women's networks was associated with decreased odds of substance use. Women who did not use substances by 12months post treatment intake had more non-users among their isolates at 6months compared to those who used substances. No association was found between support availability and likelihood of substance use. ConclusionsBoth network composition and structure could be relevant foci for network interventions e.g. helping women change network composition by reducing substance users as well as increasing network connections. Isolates who are not substance users may be a particular strength to help women cultivate within their network to promote sustained sobriety post treatment.

Prevalence and Resistance Profile of Acinetobacter baumannii Clinical Isolates from a Private Hospital in Khartoum, Sudan

Introduction: Acinetobacter baumannii is an important cause of nosocomial infections worldwide. It is difficult to control, and the infections caused by it are difficult to treat, because it is multidrug resistant. Objectives: This retrospective study was conducted to determine the prevalence and antibiotic resistance pattern of A. baumannii at Royal Care International Hospital, Khartoum, Sudan over a 37 month period. Methodology: Antimicrobial susceptibility testing of the isolates was performed by the disk diffusion method as recommended by Clinical Laboratory and Standards Institute CLSI [1]. Result: Non duplicate 275 A. baumannii were isolated out of a total 2899 pathogenic Gram negative isolates (9.5% prevalence). The most frequently isolated A. baumannii was from ICU patients (72%) followed by inpatients (24%) and outpatients (4%). The greatest number of isolates were recovered from sputum (61%) followed by wound (19%). The Resistance rates were higher than most of the internationally reported levels. Cephalosporins, aminoglycoside, aztreonam, fluoroquinolones and carbapenems are becoming practically ineffective, where the colistin elicited the highest susceptibility levels. Conclusion: This report shows for the first time (to our knowledge) the prevalence and resistance profile of A. baumannii in Sudan. The prevalence will help to conduct better infection control policy, and an update the local antibiogram will improve the knowledge of antimicrobial resistance patterns in our region.

Characteristics of enterotoxin distribution, hemolysis, lecithinase, and starch hydrolysis of Bacillus cereus isolated from infant formulas and ready-to-eat foods

Bacillus cereus is a ubiquitous environmental microbe implicated as a main cause of food poisoning with various symptoms, depending on the strain type and the isolation source. In this study, the potential virulence factors and biochemical properties of B. cereus isolated from infant formulas and ready-to-eat (RTE) foods were analyzed and compared. A total of 347 B. cereus strains were isolated and identified from 687 infant food formulas and RTE food samples. All the isolates had one or more enterotoxin genes, and one-half of the strains had all 3 enterotoxin genes (hbl, nhe, and cytK) that are involved in food poisoning in humans. Here, all the 3 genes were detected in 50% of the B. cereus isolates from RTE foods and only 14% of the isolates were identified from infant formulas. The latter harbored low cytK and bceT, and very low hbl genes. Most B. cereus isolates possessed the hemolysis gene, but not the ces gene. The infant formula isolates showed stronger hemolysis activity than the other isolates. In addition, 26% of the total isolates showed low lecithinase activities and 10% showed high lecithinase activities. A greater number of isolates from the infant formula showed high lecithinase activity than those from the RTE foods. Approximately 83% of the isolates were positive and 17% were negative for starch hydrolysis. Over 90% of the RTE food isolates and only 35% of the infant formula isolates were positive for starch hydrolysis. However, all the strains possessed nhe, but their harboring patterns of hbl and cytK were significantly different. Most starch-hydrolyzing strains possessed hbl, but only 23% nonstarch-hydrolyzing isolates possessed this gene. Moreover, very low nonstarch hydrolyzing strains harbored cytK. Most nonstarch-hydrolyzing isolates showed high lecithinase and strong hemolysis activities, and very low hbl and cytK harboring. In summary, most infant formula isolates showed stronger hemolysis and higher lecithinase activities with lower frequency of harboring hbl and cytK and lower starch hydrolysis compared with RTE food isolates.

Spatial Epidemiology ofEscherichia coliO157:H7 in Dairy Cattle in Relation to Night Roosts OfSturnus vulgaris(European Starling) inOhio,USA(2007–2009)

The goal of our study was to use spatial scan statics to determine whether the night roosts of European starlings (Sturnus vulgaris) act as point sources for the dissemination of Escherichia coli O157:H7 among dairy farms. From 2007 to 2009, we collected bovine faecal samples (n = 9000) and starling gastrointestinal contents (n = 430) from 150 dairy farms in northeastern Ohio, USA. Isolates of E. coli O157:H7 recovered from these samples were subtyped using multilocus variable-number tandem repeat analysis (MLVA). Generated MLVA types were used to construct a dendrogram based on a categorical multistate coefficient and unweighted pair-group method with arithmetic mean (UPGMA). Using a focused spatial scan statistic, we identified statistically significant spatial clusters among dairy farms surrounding starling night roosts, with an increased prevalence of E. coli O157:H7-positive bovine faecal pats, increased diversity of distinguishable MLVA types and a greater number of isolates with MLVA types from bovine-starling clades versus bovine-only clades. Thus, our findings are compatible with the hypothesis that starlings have a role in the dissemination of E. coli O157:H7 among dairy farms, and further research into starling management is warranted.

Isolation of Shigella species and their resistance patterns to a panel of fifteen antibiotics in mid and far western region of Nepal

ObjectiveTo determine the antimicrobial resistance patterns of Shigella species to the most commonly used antibiotics in mid and far western part of Nepal. MethodsStool samples were collected from 458 patients who came from mid and far western region of Nepal, attending OPD & IPD Departments of Nepalgunj Medical College, Nepal, between the periods of September 2011 to March 2013. Standard microbiological procedures were used for isolation and identification of Shigella species while the disc diffusion test was used to determine the antimicrobial resistance patterns of the recovered isolates. ResultsA total of 65 isolates were identified as Shigella species. Shigella flexneri, Shigella dysenteriae, Shigella boydii and Shigella sonnei were accounted respectively for 43.07%, 27.69%, 21.53% and 7.69% of the total number of Shigella isolated. Resistances to nalidixic acid (95.38%), ampicillin (84.62%), co-trimoxazole (81.54%) and ciprofloxacin (46.15%) were observed. Greater number of isolates (38.46%) was recovered from those aged 1-10 years. This was statistically significant (P<0.05), compared to the other age groups. ConclusionsThe study revealed the endemicity of shigellosis with Shigella flexneri as the predominant serogroup. Children were at a higher risk of severe shigellosis. The results also suggest that nalidixic acid, ampicillin, co-trimoxazole and ciprofloxacin should not be used empirically as the first line drugs in the treatment of shigellosis. Periodic analysis of resistance patterns is necessary for the appropriate selection of empirical antimicrobial therapy.

Comparison of conventional method and automatized vitek sysytem in the detection of extended-spectrum beta-lactamase in Escherichia coli and Klebsiella pneumoniae isolates

Beta-lactamase production is the most important mechanism in resistance development of Gram negative bacteriae. Extended spectrum beta-lactamases (ESBL) enzymes hydrolyse penicillin and cephalosporins. Many ESBLs are derived by genetic mutation from naturally occuring enzymes. ESBL can be detected by phenotypic and genotypic methods. In our study, we compared the ESBL detection performance of automatized Vitek version 2.0 and double disk synergy among Escherichia coli and Klebsiella pneumoniae isolates which were previously detected as ESBL (+) by combined disk method at Izmir University School of Medicine Department of Medical Microbiology. The comparison of double disk synergy (DDS) and automatized Vitek system (Biomerieux, France) in ESBL positivity detection of E. coli and K.pneumoniae strains which were isolated between 30.05.2012 to 23.01.2013 at Izmir University School of Medicine Medical Microbiology Laboratory (Izmir, Turkey) was evaluated. The ESBL detection of the strains was previouly studied by combination of ceftazidime/clavulanic acid (30/10 μg) and cefotaxime/clavulanic acid (30/10 μg). 117 isolates consisted of ESBL(+) 106 E.coli and 11 K. pneumoniae. Ten (%8.5) E. coli isolates were Vitek (-) and double disk synergy (+) for ESBL detection. Three E. coli isolates were Vitek (+) and DDS (-) for ESBL detection. All of the K. pneumoniae isolates were detected positive for ESBL by both Vitek system and DDS. There are various methods in ESBL detection. Although Vitek automatized system reported false negative results in our study, it can provide rapid data for routine laboratories. We think that further studies with greater number of isolates are necessary. Key words: ESBL, cephalosporin resistance, Vitek 2, Gram negative bacteria.

Caracterização de populações de Ralstonia solanacearum Smith em tabaco (Nicotiana tabacum L.) no Brasil

Ralstonia solanacearum, causal agent of bacterial wilt on different hosts, including members of Solanaceae, causes severe losses in tobacco crop, if not managed. It is a complex species and classified in several ways. Lately, the species was divided into three taxonomic levels: phylotype, sequevar and clone. Due to the lack of studies on populations of R. solanacearum in tobacco, this research aimed to characterize 120 isolates from soil and wilted tobacco plants, from 13 counties from Parana, 24 from Santa Catarina, 13 from Rio Grande do Sul, one from Paraiba and two from Pernambuco, by biovar, phylotype, and by using repetitive polymerase chain reaction (rep-PCR) element (BOX, ERIC and REP) primers. The results indicated that all isolates belong to the biovar 1 and phylotype II. Although there was homogeneity regarding biovar and phylotype, the results of rep-PCR allowed the formation of six groups (A, B, C, D, E and F) from 61% of similarity, regardless of sample type, geographical origin, collecting date or cultivar. Groups A and B were those that had the greatest number of isolates, 47 and 20 clonal lines, respectively. Knowledge regarding R. solanacearum population variability as well as the virulence of different isolates may help in the success of breeding programs and integrated disease management.

Bacteria etiological agents causing respiratory tract infections in children and their resistance patterns to a panel of ten antibiotics

Objective To study the bacteria etiological agents of respiratory tract infection among 280 school children in South East Nigeria, and to determine their antimicrobial resistance patterns to a panel of ten antibiotics. Methods Throat swabs (280) were collected from students in four boarding schools located in Enugu and Onitsha metropolis. Standard microbiological procedures were used to screen these swabs to determine the prevalence of respiratory pathogens while the disc diffusion test was used to determine the antimicrobial resistance patterns of the recovered isolates. Results Of the 280 samples screened, 57.1% were positive. Haemophilus influenzae was the most prevalent (16.1%), followed by Streptococcus pyogenes (13.9%), Klebsiella pneumoniae (12.5%), Streptococcus pneumoniae (6.8%), Staphylococcus aureus (5.4%) and Corynebacterium diphtheriae (2.5%). More isolates were recovered in the two male schools investigated. However, there was no significant difference in the overall prevalence of isolates according to sex or school location of the subjects. Greater number of isolates (56%) was recovered from those aged 11–14 years. This was statistically significant (P<0.05), compared to the other two age groups (15–18 years and 19–23 years). The pattern of resistance varied according to the bacteria species. There were multi-resistant isolates. Since these students stand the risk of contracting respiratory tract infection particularly from reservoirs among them, there is need to increase surveillance and develop better strategies to curb the increasing prevalence of respiratory tract infection in this and other similar regions of Africa. Conclusions The spectrum of bacteria causing respiratory tract infection is still wide in Nigeria. Many isolates showed appreciable levels of antibiotic resistance apparently due to antibiotic abuse. Development of new strategies to curb this increasing prevalence of respiratory tract infection is warranted.