Comparison of ferment sugars, produce hemolysis and measuring growth in methicillin-resistant and methicillin-sensitive Staphylococcus aureus isolates from inpatients and healthcare workers in Gorgan Hospitals, North of Iran

The mec A gene in Staphylococcus aureus leads to production of new penicillin-binding protein called PBP2a.This change may follow some changes in other phenotypes. The aim of this study was the comparison of Ferment Sugars, Produce Hemolysis and Measuring Growth in MRSA and MSSA isolates. 188 Staphylococcus aureus isolates separated from inpatients and healthcare workers (healthy carriers)were studied.Bacterialcultures in blood agar environment at 37°C during 24h and at 4°C during other 24h were applied for studying hemolysis. Sugar fermentation carried out in phenol red Broth medium, containing glucose, galactose, arabinose, fructose, xylose, ramnose, mannose, sucrose, trehalose, raffinose or maltose. For determining bacterial growth,bacterial concentration of 103was taken each hour during 12 cultured in MHAand colonies were counted after 24h.The mean amount of hemolysis diameter in MRSA isolates was rather more than that of MSSA isolates. The difference between MRSA and MSSA isolates were significant as to fermenting ramnose, trehalose, galactose and xylose. The mean rate of growth in MRSAwere significantly different from that of MSSAisolates (p<0.05).Resistance to methicillin in Staphylococcus aureus isolates accompanies the increase of ability to ferment sugars. This phenomenon may be one of reasons for increased pathogenicity of MRSA isolates; So results shows the logarithmic phase is longer in MRSA isolates, This may implicate that PBP2a production in methicillin-resistant isolates follows slowing down nutrients entrance into the bacterium that in turn may causes slow growth

Fosfomycin: Mechanisms and the increasing prevalence of resistance

There are challenges regarding increased global rates of microbial resistance and the emergence of new mechanisms that result in microorganisms becoming resistant to antimicrobial drugs. Fosfomycin is a broad-spectrum bactericidal antibiotic effective against Gram-negative and certain Gram-positive bacteria, such as Staphylococci, that interfere with cell wall synthesis. During the last 40 years, fosfomycin has been evaluated in a wide range of applications and fields. Although numerous studies have been done in this area, there remains limited information regarding the prevalence of resistance. Therefore, in this review, we focus on the available data concerning the mechanisms and increasing resistance regarding fosfomycin. © 2019 The Authors

Bedaquiline: Current status and future perspectives

The development of drug-resistant tuberculosis (TB) is a major threat worldwide. Based on World Health Organization (WHO) reports, it is estimated that more than 500 000 new cases of drug-resistant TB occur annually. In addition, there are alarming reports of increasing multidrug-resistant TB (MDR-TB) and the emergence of extensively drug-resistant TB (XDR-TB) from different countries of the world. Therefore, new options for TB therapy are required. Bedaquiline (BDQ), a novel anti-TB drug, has significant minimum inhibitory concentrations (MICs) both against drug-susceptible and drug-resistant TB. Moreover, BDQ was recently approved for therapy of MDR-TB. The current narrative review summarises the available data on BDQ resistance, describes its antimicrobial properties, and provides new perspectives on clinical use of this novel anti-TB agent. © 2021 The Author(s

“Microbiota, symbiosis and individuality summer school” meeting report

How does microbiota research impact our understanding of biological individuality? We summarize the interdisciplinary summer school on “Microbiota, symbiosis and individuality: conceptual and philosophical issues” (July 2019), which was supported by a European Research Council starting grant project “Immunity, DEvelopment, and the Microbiota” (IDEM). The summer school centered around interdisciplinary group work on four facets of microbiota research: holobionts, individuality, causation, and human health. The conceptual discussion of cutting-edge empirical research provided new insights into microbiota and highlights the value of incorporating into meetings experts from other disciplines, such as philosophy and history of science

Visual Performance Fields: Frames of Reference

Performance in most visual discrimination tasks is better along the horizontal than the vertical meridian (Horizontal-Vertical Anisotropy, HVA), and along the lower than the upper vertical meridian (Vertical Meridian Asymmetry, VMA), with intermediate performance at intercardinal locations. As these inhomogeneities are prevalent throughout visual tasks, it is important to understand the perceptual consequences of dissociating spatial reference frames. In all studies of performance fields so far, allocentric environmental references and egocentric observer reference frames were aligned. Here we quantified the effects of manipulating head-centric and retinotopic coordinates on the shape of visual performance fields. When observers viewed briefly presented radial arrays of Gabors and discriminated the tilt of a target relative to homogeneously oriented distractors, performance fields shifted with head tilt (Experiment 1), and fixation (Experiment 2). These results show that performance fields shift in-line with egocentric referents, corresponding to the retinal location of the stimulus

The landscape of cognitive neuroscience: challenges, rewards, and new perspectives

No abstract available

The Prevalence of Shiga toxin-1 in non-Shigella dysenteriae isolates collected from diarrhea samples in patients, Ahvaz, Iran

BACKGROUND: Acute diarrhea is a major public health problem particularly in developing countries. Shigellosis is one of the substantial causative agents of microbial dysentery and still has a remarkable prevalence particularly in areas with poor hygienic infrastructures. The probable existence of the deadly Shiga toxin (Stx) protein in some Shigella strains would manifest life-threatening clinical symptoms of the infection. METHODS: The aim of this study was to determine the presence of Shigella toxin 1 (Stx1) in isolated from patients with diarrhea. Totally, 227 Shigella species including 60 S. flexneri, 157 S. sonnei, and 10 S. boydii were collected from diarrheal patients in tropical infectious diseases research center of Ahvaz, Iran, during 2013-2015. The isolates were collected mostly from the intensive care unit, infectious disease, and surgery settings. The isolates were identified and the polymerase chain reaction (PCR) was performed to detect the stx gene. RESULTS: The results indicated that none of them encode the stx1 gene. CONCLUSION: Isolates of this study were not capable of stx1 encoding. Future investigations should consider the relations between other Shigella species and Shigella toxin in Iran

Frequency of blaIMP, blaNDM, blaKPC, and blaVIM carbapenemase-encoding genes among gram-negative bacteria isolates from hospitalized patients in Baghdad City, Iraq

Carbapenemase-encoding genes have been spreading among gram-negative bacteria, which is considered the most important threats to human health. Metallo p-lactamases including IMP, VIM, and NDM are the most predominant types, which confer resistance to Carbapenem group. This study aimed to investigate the frequency of blaNDM, blaKPC, blaVIM, and blaIMP genes across gram-negative bacteria isolated from different clinical specimens in Medical City Hospital in Baghdad, Iraq. Fifty-two isolates were identified phenotypically using conventional biochemical tests. Vitek 2 identification system was used for confirmation of the identification. The antimicrobial sensitivity for the isolates was performed using Kirby-Bauer disk diffusion method. The carbapenemase-encoding genes (blaIMP, blaVIM, blaNDM, and blaKPC) were screened by polymerase chain reaction (PCR)- based technique. The results showed that, from a total of 52 isolates isolated from hospital in Baghdad city, 13 (25) were Acinetobacter baumannii and 39 (75) were Enterobacteriaceae (10 of Serratia spp, 17 of E. coli, and 12 of Enterobacter cloacae). According to antibiotic susceptibility results, 96 of isolates were resistance to ceftriaxone, 92.3 to ciprofloxacin, and 90.4 to cefotaxime by phenotypic testing. Within the isolates, blaVIM gene was the most prevalent gene, which was detected in 48.1 of the isolates, followed by blaIMP gene in 19.2, blaNDM gene in 9.6, and blaKPC gene in 5.7. This study reveals that the dissemination rate of carbapenemase-encoding genes was not as reported to be high among isolates. The results showed higher frequency to the blaVIM gene than other encoding genes for carbapenemase-encoding genes. These results suggest a periodic screening and follow-up program to detect antibiotic resistant genes, and also the need to develop appropriate management for antimicrobial resistance. © 2021. All Rights Reserved