Background Urinary Tract Infection (UTI) is one of the most common bacterial infectious diseases which causes considerable morbidity and costly health problems. Uropathogenic Escherichia coli (UPEC), the most common pathogen causing UTI, is a highly heterogeneous group of extraintestinal pathogenic E. coli (ExPEC) which may carry a variety of virulence factors and belonging to different phylogenetic backgrounds. The current study aimed to investigate the frequency and association between various virulence factors (VFs) and phylogenetic groups of UPEC and commensal isolates. Methods UPEC and commensal E. coli strains isolated from UTI and feces of healthy humans were compared for the presence of VFs and phylogenetic groups. Association between virulence genes was investigated and cluster analysis was employed. Results According to the results, among a 30 virulence markers tested, the pathogenicity-associated island (PAI), papAH, papEF, fimH, fyuA, and traT genes prevalence were statistically significant in UPEC isolates. A strong association was found between the B2 and D phylogenetic groups and clinical isolates of UPEC; while, commensal isolates were mostly associated with phylogenetic group A. The aggregated VFs scores were more than twice higher in the UPEC isolates in comparison with the commensal isolates. Interestingly, the B2 group in both UPEC and commensal isolates had the highest VF scores. A strong positive association was found between several virulence genes. The clustering results demonstrated that UPEC or commensal E. coli isolates were highly heterogeneous due to different composition of their virulence gene pool and pathogenicity islands. Conclusion Genetic structure and VFs of UPEC strains vary from region to region; therefore, to control the UTI, the epidemiological aspects and characterization of the UPEC isolates need to be investigated in different regions. Since UPEC isolates are generally originate from the commensal strains, it may be feasible to reduce the UTI burden by interfering the intestinal colonization, particularly in the highly pathogenic clonal lineages such as B2.

A three-component composite consisted of graphene oxide, cobalt ferrite, and silver nanoparticles has been prepared by a facile method and fully characterized. The antibacterial activity of this composite has been greatly enhanced after being combined with ciprofloxacin drug. This clearly showed the occurrence of a strong synergistic effect between ciprofloxacin and the Ag NPs in the composite. The ciprofloxacin-conjugated composite was found to be a potent antimicrobial agent while having rather low cytotoxicity and high stability. The studies based on field emission scanning electron microscopy (FESEM) analysis and zeta potential measurement have revealed that the composite sticks to the bacterial cell wall causing irreversible cell damage. This multifunctional magnetic nanocomposite was also examined as drug delivery system for ciprofloxacin in solutions with different pH. It was observed that the release of ciprofloxacin in this system is pH-sensitive with gradual and controlled manner. Mechanisms for the synergistic effect and drug release behavior, as well as explanation for the antibacterial action, of the nanocomposite were also demonstrated.

In this study, we evaluated the antiviral activity of gold nanoparticles (AuNPs) against the foot-and-mouth disease virus (FMDV), that causes a contagious disease in cloven-hoofed animals. The anti-FMDV activity of AuNPs was assessed using plaque reduction assay. MTT assay was used for quantitatively measuring the cytopathic effect caused by the viral infection. The 50% cytotoxicity concentration of nanoparticles was measured and found to be 10.4 μg/ml. The virus yield reduction assay showed that AuNP have an approximately 4-fold virus titer reduction compared with controls. Plaque reduction assay showed that at non-cytotoxic concentrations, AuNPs do not show extracellular virucidal activity and inhibition of FMDV growth at the early stages of infection including attachment and penetration. Time-of-addition experiments revealed that AuNPs inhibited post-entry stages of viral replication concomitant with the onset of intracellular viral RNA synthesis; however, the mechanism of AuNPs against FMDV was unclear.

Background: Urinary tract infection (UTI) is a common bacterial disease which may cause chronic renal failure and hypertension. Many reports suggest that the rate of antibiotic resistance to infectious organisms is increasing.Objectives: This study aimed to detect and also compare the frequency and drug resistance pattern of Gram negative bacteria isolated from patients with community-acquired UTIs in Isfahan.Patients and Methods: In this cross-sectional descriptive study, 702 samples from 476 females and 226 males referred to medical centers in Isfahan city from June to September 2011 were collected, we investigated the urine cultures and antibiotic sensitivity of the isolated organisms were measured.Results: Urinary infectious was detected in 203 persons. The most prevalence isolated bacteria were Escherichia coli 138 (68%), followed by Klebsiella spp. (13%). Antibiotic resistance pattern of Gram negative bacteria isolated was investigated. Among E. coli isolates the most antibiotic sensitivity and resistance were related to Nitrofurantoin, Cotrimoxazol and Nalidixic acid, Trimetsulpha respectively. Klebsiella spp. isolates were the most antibiotic sensitive to Cotrimoxazol and Cipropheloxacin and the most antibiotic resistant to Trimetsulpha, Cipropheloxacin and Nalidixic respectively.Conclusions: With regards to the continuous changing in causative microorganisms isolated from patients with UTI and antibiotic sensitivity patterns, it is recommended that bacterial sensitivity patterns in populations are determined in any region annually

Background:Nowadays natural products such as pure compounds and plant extract scan provide unlimited opportunities for new antiviral drugs. Newcastle disease virus (NDV) is one of the most important viral diseases in poultry industry. Vaccination could provide protection against NDV outbreaks, but it is not sufficient because infections by NDVs have remained frequent around the world.Objectives:The current research aimed to study Achillea millefolium and Thymus vulgaris antiviral activity against Newcastle disease virus (NDV).Materials and Methods:The antiviral activity of the plants was measured by the reduction assay of viral titer, and explained by inhibition percentage (IP).Results:Inhibition percentage was determined as 10 1.75, which indicated the ability of the extracts to reduce the viral potency by more than 56 folds.Conclusions:Both plants were found effective against Newcastle disease virus.

Foot-and-mouth disease (FMD) is an extremely contagious viral disease of cloven-hoofed animals that can lead to huge economic losses in the livestock production. No antiviral therapies are available for treating FMD virus (FMDV) infections in animals. The antiviral effects of magnesium oxide nanoparticles (MgO NPs) on the FMDV were investigated in cell culture. The viability of the cells after MgO NP treatment was determined using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The direct effects of MgO NPs on the FMDV in extracellular (virucidal assay) and also different stages of virus replication (antiviral assay) were evaluated by plaque reduction assay. The results showed that MgO NPs were safe at concentrations up to 250 µg/ml in the Razi Bovine kidney cell line. The treatments with NPs indicated that the MgO NPs exerted in vitro virucidal and antiviral activities. Plaque reduction assay revealed that MgO NPs can inhibit FMDV by more than 90% at the early stages of infection such as attachment and penetration but not after penetration. The results of this study suggested that NPs might be applied locally as an antiviral agent in early stages of infection in susceptible animals.

Introduction: Diarrheagenic Escherichia coli (DEC) is a major etiologic agent among the pathogens that cause diarrhea in children. Methodology: To investigate the presence and pathotypes of DEC in children under five years of age, living in the province of Khouzestan, Iran. 208 diarrhea stool samples were screened by multiplex-PCR. The isolated DEC isolates were investigated for resistance to various antimicrobials including the production of extended-spectrum beta-lactamases (ESBLs) and phylogenetic groups were determined. Results: DEC isolates were identified in 54 (26%) diarrhea samples, and 4 (7%) cases contained two DEC pathotypes. DEC isolated included 35 (16.8%) enteroaggregative E. coli (EAEC), ten (4.8%) enteropathogenic E. coli (EPEC), six (2.9%) enteroinvasive E. coli (EIEC), six (2.9%) enterotoxigenic E. coli (ETEC) and one (0.48%) LEE-positive EAEC. Shiga-toxin producing E. coli (STEC) was not identified in any diarrheal samples. The most prevalent resistance was observed with ceftazidime (88%), followed by ceftizoxime (83%) and ceftriaxone (71%). The majority of isolates (> 75%) were sensitive to Imipenem, ciprofloxacin, and amikacin. More than 65% of the pathogenic isolates showed a multidrug-resistant phenotype. ESBL-producing strains was observed in 79.3% of all DEC isolates. Phylogenetic group B2 was the most predominant group with a frequency of 44.8%. A significant association was observed between the B2 phylogenetic group and the DEC isolates (P < 0.05). Conclusions: Overall, our findings highlight the importance of the role of DEC isolates in the etiology of diarrhea in children in Iran. The progressive increase in antimicrobial resistance among DEC isolates makes it imperative to implement policies to control the spread of resistant bacteria.

Background The emergence of metallo-β-lactamase (MBL)-producing isolates is alarming since they carry mobile genetic elements with great ability to spread; therefore, early detection of these isolates, particularly their reservoir, is crucial to prevent their inter- and intra-care setting dissemination and establish suitable antimicrobial therapies. The current study was designed to evaluate the frequency of antimicrobial resistance (AMR), MBL producers and identification of MBL resistance genes in Escherichia coli strains isolated from fecal samples of the healthy children under 3 years old. A total of 412 fecal E. coli isolates were collected from October 2017 to December 2018. The study population included healthy infants and children aged < 3 years who did not exhibit symptoms of any diseases, especially gastrointestinal diseases. E. coli isolates were assessed to determine the pattern of AMR. E. coli isolates were assessed to determine the pattern of AMR, the production of extended spectrum β-lactamase (ESBL) and MBL by phenotypic methods. Carbapenem-resistant isolates were investigated for the presence of MBL and carbapenemase genes, plasmid profiling, and the ability of conjugation. Results In sum, AMR, multi-drug resistance (MDR) and ESBL production were observed in more than 54.9, 36.2 and 11.7% of commensal E. coli isolates, respectively. Out of six isolates resistant to imipenem and meropenem, four isolates were phenotypically detected as MBL producers. Two and one E. coli strains carried the blaNDM-1 and blaVIM-2 genes, respectively and were able to transmit imipenem resistance through conjugation. Conclusion Our findings showed that children not exposed to antibiotics can be colonized by E. coli isolates resistant to the commonly used antimicrobial compounds and can be a good indicator for the occurrence and prevalence of AMR in the community. These bacteria can act as a potential reservoir of AMR genes including MBL genes of pathogenic bacteria and lead to the dissemination of resistance mechanisms to other bacteria.