Background: Gram-negative bacilli are primarily responsible for the most common pediatric infections. Frequently, Escherichia fergusonii is identified as E. coli because of its close genetic proximity. Objectives: We aimed at the isolation and identification of multi-resistant strains of E. fergusonii, affecting children under two months of age. Methods: Strains were isolated from infectious processes and were identified phenotypically and molecularly. The microdilution method (MicroScan, autoSCAN-4) and the disk diffusion method (modified Kirby Bauer) were used to analyze antibiotic susceptibility. Results: Strains isolated were multi-resistant. Molecular identification provided the correct taxonomic assignment. Escherichia fergusonii strains were wrongly identified as E. coli with the phenotypic identification method. In addition, Pseudomonas aeruginosa and Klebsiella pneumoniae were identified. The best sensitivity results were obtained with Ceftazidime/avibactam and ceftolozane/tazobactam. Conclusions: We provided the first report of isolation and identification of multi-resistant E. fergusonii strains affecting children under two months of age in a neonatal intensive care unit.

Background: Several prominent bacterial species known to induce diarrhea in human hosts encompass Escherichia coli, Escherichia albertii, Escherichia fergusonii, and various Shigella spp. Given that these organisms contribute to the burden of food-borne illness, it is essential to rapidly and correctly identify them in a clinical laboratory or food microbiology unit to prevent their transmission and spread. These pathogens are often mistakenly identified because of their genetic and phenotypic similarities. Phenotypic tests are not highly discriminatory and are time-consuming. Whole-genome sequencing is expensive and unavailable in most clinical laboratories. Materials and Methods: To simplify their rapid detection, we improved an available multiplex polymerase chain reaction (PCR) assay targeting three species-specific primers, including Eco (the main target for E. coli identification), Ealb (specific for E. albertii), and Efer (specific for E. fergusonii), by adding ipaH and lacY to additionally discriminate between the highly similar Shigella spp. and enteroinvasive E. coli (EIEC) organisms. Primers were tested on 65 defined isolates, including E. coli (n=29), Shigella spp. (n=26), E. fergusonii (n=1), E. albertii (n=1), and other Enterobacterales (n=8). Results: All examined E. coli yielded two amplicons of the expected size (Eco and lacY), except for EIEC, which had three bands (Eco, lacY, and ipaH). All Shigella spp. yielded two amplicons (Eco and ipaH). E. fergusonii had only one band (Efer), and E. albertii also yielded one band (Ealb). Other Enterobacterales that were tested for validation did not demonstrate a product, except for Klebsiella pneumoniae and Klebsiella oxytoca (both lacY). Conclusion: The assay was shown to be a way forward for rapid, specific, and cost-effective primary discrimination of these important or emerging enteropathogens that can be used in clinical and research laboratories.

Introduction: Tannins are a group of polyphenolic compounds that are widely present in plants as an anti-nutritional factor. The rumen of wild ruminants contains novel microbes that detoxify antinutrients and improve feed digestion. The present study evaluated tannase-producing bacteria isolated from the rumen of Fallow deer (Dama dama), livestock potential feed additives.Materials and Methods: Tannase-producer bacteria (TPBs) were isolated from the rumen using a 2% tannic acid- plate and tannase activity (TAA) assayed by the spectrophotometer method. The bacterial DNA was extracted through boiling and amplified using a PCR reaction. The Sanger technique and BLAST software were used to identify the strains. Antibacterial (ABA) and antibiogram tests were performed by the disc diffusion method, and the acid and bile resistance of isolates were examined using broth cultures.Results: The results indicated that TPBs belonged to Klebsiella, Enterobacter, and Escherichia genera. Escherichia fergusonii GHMGHE44 (9.39 Uml-1) and Enterobacter cloacae GHMGHE26 (1.79 Uml-1) were the strongest and weakest tannin degraders (p<0.01). Among the isolates, bile and acid resistance were insignificant (p>0.01) but E. fergusonii GHMGHE28 (9.48 CFU ml-1) had a significant survival rate compared to E. cloacae GHMGHE25 (9.07 CFU ml-1) at pH of 7 (p<0.01). Also, K. pneumoniae subsp. rhinoscleromatis GHMGHE27 (32.66 mm), E. coli GHMGHE47 (40.66 mm), and E. fergusonii GHMGHE48 (24.66 mm) were potently suppressed the pathogen E. Coli, S. aureus and P. aeruginosa, respectively (p<0.01). Against used antibiotics, E. asburiae GHMGHE22 was the most sensitive isolate while others showed diverse reactions (p<0.01).Discussion and Conclusion: The findings showed that TPBs have the potential to study as commercial animal feed additives (AFA).

Since the beginning, mosquito-borne diseases like dengue fever, encephalitis, yellow fever, malaria, and filariasis have been caused by numerous medically significant pathogens and parasites, including viruses, bacteria, and protozoans. This indicates the necessity for the ongoing creation of new and effective mosquito-borne disease control strategies in Saudi Arabia and internationally. This investigation has tried to assess the potential larvicidal capacity of local bacteria isolated from the soil of the Rahat region of Makkah, Saudi Arabia for the bio-control of Aedes aegypti larvae, a main cause of dengue. The bacteria were identified using morphological and molecular characteristics. Bioassays were used to determine the pathogenicity of various strains against A. aegypti larvae. A total of 66 different bacteria were isolated. Overall, four (6.06%) of the 66 bacteria caused mortality in the A. aegypti larvae, and only two (Brevibacillus centrosporus, and Cytobacillus firmus) caused 100% mortality in 24 h. After 48 h, two isolates (Escherichia fergusonii1 and E. fergusonii 2) caused mortality of over 70%. The outcomes of this investigation exhibited that local isolates of bacteria in the soils of the Rahat region of Makkah, Saudi Arabia, have larvicidal ability. These bacteria have shown larvicidal effects on the larvae of A. aegypti. In conclusion, further studies are required to evaluate other mechanisms that contribute to the production of larvicidal toxins in these bacteria.

Background: Enteroaggregative Escherichia coli (EAEC) has recently been identified as the cause of epidemic and endemic chronic watery diarrhea worldwide, especially in developing countries. The aim of this study was to determine the frequency of this strain and its important virulence genes in diarrhea samples. Methods: This study was performed on 80 Escherichia coli isolates from children with diarrhea referred to Imam Hossein hospital, Isfahan, Iran. The bacteria were confirmed using biochemical tests and multiplex polymerase chain reaction (multiplex PCR) was performed to detect aggR, aap, aatA genes in EAEC strains. Findings: The frequency of EAEC was 21 (26. 6%). According to multiplex PCR results, the aggR, aap, and aatA genes were detected in 21 (100%), 7 (33%), and 3 (14. 3%) of strains, respectively. Moreover, 7 strains (33. 3%) harbored two aggR and aap genes, 3 (14. 3%) carried the aatA and aggR genes, and aatA and aap genes were presented in 2 strains (9. 5%). None of the strains had 3 genes simultaneously. Conclusion: This study provides the first report of a relatively high frequency of typical EAEC strains in children under 5 years of age with symptoms of diarrheal disease in Isfahan. Moreover, we found that the EAEC strains not only exhibited high frequency, but also showed a high frequency of carrying virulence genes especially aggR that indicated the importance of identifying this strain in patients showing the symptoms of acute and chronic diarrhea, especially in our country, as the diagnosis of this strain is not done routinely.

Rumen acidosis can be caused by overeating of readily fermentable carbohydrate, and as a result an imbalance may be seen in rumen microbial population. In order to characterization of lactate producing bacteria 30 isolates were collected from ruminal fluid of three male Mehraban sheep (receiving a diet containing 60% concentrate and 40% alfalfa hay) using specific cultural media. The isolates were evaluated based on gram staining, catalase activity, indole production test and their ability to ferment some sugars. Identification of isolates was undertaken using 16s rRNA gene sequences. A RFLP procedure was used to test the genetic homogeneity of isolates. Four isolates were selected and their 16s rRNA were sequenced. Based on information obtaind from Gene Bank, the isolates were closely (>99%) related to Streptococcus macedonicus, Streptococcus luteciae, Enterococcus faecalis and Escherichia fergusonii.

Background & objective: Photodynamic inactivation (PDI) has been investigated to cope with the increasing incidence of multidrug-resistant (MDR) pathogens. PDI employs nontoxic photosensitizers (PSs), which localize in the microbial cells and are activated by a specific wavelength of visible light. The main purpose of this study was to explore the PDI effect of methylene blue (MB) and toluidine blue O (TBO) on Escherichia coli (ATCC 25922) and clinical isolate of multidrug-resistant Escherichia coli.Methods: Effect of PSs concentration (12.5, 25, 50 µg/ml) and laser irradiation time (10, 20, 30 min) on lethal photosensitization was investigated.Results: Methylene blue (50 µg/ml) photosensitization using red laser light (163.8 J/cm2) was able to achieve reductions of 53.1% and 37.6% in the viable counts of Escherichia coli (ATCC 25922) and clinical isolate of MDR Escherichia coli (using starting concentrations of 104–105 CFU ml-1). TBO at 50 µg/ml, 46.8 Jcm-2, exhibited 0.7 log killing for MDR E. coli and 1.7 log killing for E. coli (ATCC 25922).Conclusion: In our study, the selected MDR isolate was more resistant to TBO-PDI-mediated killing than its ATCC reference strain. Therefore, the PDI efficacy of TBO may be affected by the antibiotic resistance mechanism that presented in MDR isolate.

A total of 114 samples collected from hospital wastewaters and rivers in Addis Ababa, Ethiopia were tested for non-sorbitol fermenting bacteria and coliphages. Sorbitol MacConkey agar is mainly used in the detection of E. coli O157:H7. However, other emerging diarrhoeagenic enteropathogens such as Plesiomonas shigelloides, Edwardsiella tarda, Providencia alcalifaciens, Escherichia albertii, Escherichia vulneris and Escherichia fergusonii were detected in the samples using this medium. Information for most of the emerging enteropathogens is scarce in most countries including Ethiopia. A total of 20 different genera, 38 species of non-sorbitol fermenting bacteria were isolated. Escherichia coli O157 could not be detected from any of the samples. All these backgrounds may mask the detection of Escherichia coli O157. Even if sorbitol MacConkey agar has several background limitations, different emerging diarrhoeagenic non-sorbitol fermenting bacteria were detected in the majority of the rivers and hospitals` wastewaters samples. The correlation between coliphages and non-sorbitol fermenting bacteria were not significant. As several bacteria have been isolated on sorbitol MacConkey agar medium, it is essential that the most selective laboratory techniques will be desired for outbreak investigation of E. coli O157, but other non-sorbitol fermenting enteropathogens should also be detected using sorbitol MacConkey agar in low resources countries.

Citrus tristeza virus (CTV) is among the most destructive pathogens of citrus and causes substantial economic losses to citrus industry worldwide. Considering recent distribution of this pathogen and its capability of transmission by existing aphid vectors in Iran, detection of this virus should be mandatory for controlling the damage caused by this pathogen in Iran, as one of the major citrus producing countries. Toward this aim, developing a reliable and sensitive detection method such as enzyme- linked immunosorbant assay (ELISA) would be the first step to detect CTV in large scale screenings of field samples. As the serological method requires great amounts of specific antibody, consequently preparation of a large scale antigen source for immunization process would be necessary. In this study the coat protein gene of CTV (CP25) was amplified by polymerase chain reaction from a cloned CP25 gene in pTZ57R/T and subcloned in pET26b expression vector and named pET-CP25. Two Escherichia coli strains of BL21 and Rosetta Gami (DE3) were transformed by pET-CP25. Expression of recombinant protein was induced by IPTG. The authenticity of recombinant protein was confirmed by western immunoblot analysis using a polyclonal antiserum against CTV particles. The results indicated that CTV coat protein gene was expressed in E. coli. This recombinant protein could be used as a source of antigen for immunization process.

Microbial analysis of ground water, as the sole supplying water source in many areas, must be evaluated. Because the treatment of water cannot remove all pathogenic bacteria leaked from domestic wastewater, bacterial analysis of Bojnourd groundwater sources was performed. For this reason, membrane filter (MF) technique and Most Probable Number (MPN) method were used to evaluate the microbial quality of the water. Escherichia coli (E. coli) and Enteroccocus faecalis (E. faecalis) were traced as excremental indices. E. coli was detected from three out of six stations and E. faecalis was only isolated from one station. Although molecular techniques are very rapid and exact methods for detection of microbial community and can identify ‘Viable But Not Cultivable’ (VBNC) bacteria, they are unable to make a distinction between living and non-living microorganisms. By means of a standard technique, it is possible to study living and metabolically active microorganisms. Due to the detection of E. coli and E. feacalis in some stations the sanitization of groundwater must be revised to lessen the microbial population in this groundwater.