Journal of Medical Microbiology 

About: Journal of Medical Microbiology is an academic journal published by Microbiology Society. The journal publishes majorly in the area(s): Virulence & Escherichia coli. It has an ISSN identifier of 0022-2615. Over the lifetime, 8501 publications have been published receiving 270465 citations. The journal is also known as: JMM.

Candida species: current epidemiology, pathogenicity, biofilm formation, natural antifungal products and new therapeutic options

Abstract: The incidence of fungal infections has increased significantly, so contributing to morbidity and mortality. This is caused by an increase in antimicrobial resistance and the restricted number of antifungal drugs, which retain many side effects. Candida species are major human fungal pathogens that cause both mucosal and deep tissue infections. Recent evidence suggests that the majority of infections produced by this pathogen are associated with biofilm growth. Biofilms are biological communities with a high degree of organization, in which micro-organisms form structured, coordinated and functional communities. These biological communities are embedded in a self-created extracellular matrix. Biofilm production is also associated with a high level of antimicrobial resistance of the associated organisms. The ability of Candida species to form drug-resistant biofilms is an important factor in their contribution to human disease. The study of plants as an alternative to other forms of drug discovery has attracted great attention because, according to the World Health Organization, these would be the best sources for obtaining a wide variety of drugs and could benefit a large population. Furthermore, silver nanoparticles, antibodies and photodynamic inactivation have also been used with good results. This article presents a brief review of the literature regarding the epidemiology of Candida species, as well as their pathogenicity and ability to form biofilms, the antifungal activity of natural products and other therapeutic options.

Pseudomonas aeruginosa - a phenomenon of bacterial resistance.

Abstract: Pseudomonas aeruginosa is one of the leading nosocomial pathogens worldwide. Nosocomial infections caused by this organism are often hard to treat because of both the intrinsic resistance of the species (it has constitutive expression of AmpC β-lactamase and efflux pumps, combined with a low permeability of the outer membrane), and its remarkable ability to acquire further resistance mechanisms to multiple groups of antimicrobial agents, including β-lactams, aminoglycosides and fluoroquinolones. P. aeruginosa represents a phenomenon of bacterial resistance, since practically all known mechanisms of antimicrobial resistance can be seen in it: derepression of chromosomal AmpC cephalosporinase; production of plasmid or integron-mediated β-lactamases from different molecular classes (carbenicillinases and extended-spectrum β-lactamases belonging to class A, class D oxacillinases and class B carbapenem-hydrolysing enzymes); diminished outer membrane permeability (loss of OprD proteins); overexpression of active efflux systems with wide substrate profiles; synthesis of aminoglycoside-modifying enzymes (phosphoryltransferases, acetyltransferases and adenylyltransferases); and structural alterations of topoisomerases II and IV determining quinolone resistance. Worryingly, these mechanisms are often present simultaneously, thereby conferring multiresistant phenotypes. This review describes the known resistance mechanisms in P. aeruginosa to the most frequently administrated antipseudomonal antibiotics: β-lactams, aminoglycosides and fluoroquinolones.

Differences between the gut microflora of children with autistic spectrum disorders and that of healthy children

Abstract: Children with autistic spectrum disorders (ASDs) tend to suffer from severe gastrointestinal problems. Such symptoms may be due to a disruption of the indigenous gut flora promoting the overgrowth of potentially pathogenic micro-organisms. The faecal flora of patients with ASDs was studied and compared with those of two control groups (healthy siblings and unrelated healthy children). Faecal bacterial populations were assessed through the use of a culture-independent technique, fluorescence in situ hybridization, using oligonucleotide probes targeting predominant components of the gut flora. The faecal flora of ASD patients contained a higher incidence of the Clostridium histolyticum group (Clostridium clusters I and II) of bacteria than that of healthy children. However, the non-autistic sibling group had an intermediate level of the C. histolyticum group, which was not significantly different from either of the other subject groups. Members of the C. histolyticum group are recognized toxin-producers and may contribute towards gut dysfunction, with their metabolic products also exerting systemic effects. Strategies to reduce clostridial population levels harboured by ASD patients or to improve their gut microflora profile through dietary modulation may help to alleviate gut disorders common in such patients.

Cytotoxic activity in broth-culture filtrates of Campylobacter pylori.

Abstract: Broth-culture filtrates of Campylobacter pylori induced non-lethal cytopathic effects in vitro in 7 of 9 mammalian cell lines tested Transmission electronmicroscopy revealed that the response consisted of intracellular vacuolisation Intestine 407 cells were among the most responsive and were used for routine assay About 55% of isolates of C pylori tested, originating from four geographic regions worldwide, produced cytotoxic activity The activity was neutralisable by specific antisera to broth-culture filtrates or to sonicated bacteria but not by antisera to other bacterial preparations Cytotoxic activity was heat-labile (70 degrees C for 30 min), was protease-sensitive and ammonium-sulphate precipitable It did not pass through an ultrafiltration membrane with a nominal mol-wt limit of 100 X 10(3) It was concluded that C pylori can produce a factor that alters cultured cells in vitro The relevance of this factor to the pathogenesis of gastritis associated with C pylori remains to be determined

Antifungal activity of the clove essential oil from Syzygium aromaticum on Candida, Aspergillus and dermatophyte species

Abstract: The composition and antifungal activity of clove essential oil (EO), obtained from Syzygium aromaticum, were studied Clove oil was obtained commercially and analysed by GC and GC-MS The EO analysed showed a high content of eugenol (853 %) MICs, determined according to Clinical and Laboratory Standards Institute protocols, and minimum fungicidal concentration were used to evaluate the antifungal activity of the clove oil and its main component, eugenol, against Candida, Aspergillus and dermatophyte clinical and American Type Culture Collection strains The EO and eugenol showed inhibitory activity against all the tested strains To clarify its mechanism of action on yeasts and filamentous fungi, flow cytometric and inhibition of ergosterol synthesis studies were performed Propidium iodide rapidly penetrated the majority of the yeast cells when the cells were treated with concentrations just over the MICs, meaning that the fungicidal effect resulted from an extensive lesion of the cell membrane Clove oil and eugenol also caused a considerable reduction in the quantity of ergosterol, a specific fungal cell membrane component Germ tube formation by Candida albicans was completely or almost completely inhibited by oil and eugenol concentrations below the MIC values The present study indicates that clove oil and eugenol have considerable antifungal activity against clinically relevant fungi, including fluconazole-resistant strains, deserving further investigation for clinical application in the treatment of fungal infections