A Canine Urinary Tract Infection Representing the First Clinical Veterinary Isolation of Acinetobacter ursingii

Acinetobacter species can be important opportunistic pathogens in humans, especially in healthcare settings. We report here the first isolation of Acinetobacter ursingii from an animal species; it was isolated from a canine urinary tract infection, and phenotypic identification proved unreliable. Keywords: Acinetobacter ursingii, canine, molecular diagnostics, urinary tract infection, veterinary microbiolog

Research Strategies in the Study of the Pro-Oxidant Nature of Polyphenol Nutraceuticals

Polyphenols of phytochemicals are thought to exhibit chemopreventive effects against cancer. These plant-derived antioxidant polyphenols have a dual nature, also acting as pro-oxidants, generating reactive oxygen species (ROS), and causing oxidative stress. When studying the overall cytotoxicity of polyphenols, research strategies need to distinguish the cytotoxic component derived from the polyphenol per se from that derived from the generated ROS. Such strategies include (a) identifying hallmarks of oxidative damage, such as depletion of intracellular glutathione and lipid peroxidation, (b) classical manipulations, such as polyphenol exposures in the absence and presence of antioxidant enzymes (i.e., catalase and superoxide dismutase) and of antioxidants (e.g., glutathione and N-acetylcysteine) and cotreatments with glutathione depleters, and (c) more recent manipulations, such as divalent cobalt and pyruvate to scavenge ROS. Attention also must be directed to the influence of iron and copper ions and to the level of polyphenols, which mediate oxidative stress

Human Infection Caused by Leptospira fainei

We report a human case of leptospirosis in which the spirochete was detected by dark-field microscopy examination of cerebrospinal fluid (CSF) and isolated from both CSF and blood. Leptospira fainei was identified by sequencing the 16S rDNA gene, which had been amplified by polymerase chain reaction. This case confirms the role of L. fainei as a human pathogen and extends its distribution to southern Europe

Precipitation of Phosphate Minerals by Microorganisms Isolated from a Fixed-Biofilm Reactor Used for the Treatment of Domestic Wastewater

The ability of bacteria isolated from a fixed-film bioreactor to precipitate phosphate crystals for the treatment of domestic wastewater in both artificial and natural media was studied. When this was demonstrated in artificial solid media for crystal formation, precipitation took place rapidly, and crystal formation began 3 days after inoculation. The percentage of phosphate-forming bacteria was slightly higher than 75%. Twelve major colonies with phosphate precipitation capacity were the dominant heterotrophic platable bacteria growing aerobically in artificial media. According to their taxonomic affiliations (based on partial sequencing of the 16S rRNA), the 12 strains belonged to the following genera of Gram-negative bacteria: Rhodobacter, Pseudoxanthobacter, Escherichia, Alcaligenes, Roseobacter, Ochrobactrum, Agromyce, Sphingomonas and Paracoccus. The phylogenetic tree shows that most of the identified populations were evolutionarily related to the Alphaproteobacteria (91.66% of sequences). The minerals formed were studied by X-ray diffraction, scanning electron microscopy (SEM), and energy dispersive X-ray microanalysis (EDX). All of these strains formed phosphate crystals and precipitated struvite (MgNH4PO4·6H2O), bobierrite [Mg3(PO4)2·8H2O] and baricite [(MgFe)3(PO4)2·8H2O]. The results obtained in this study show that struvite and spherulite crystals did not show any cell marks. Moreover, phosphate precipitation was observed in the bacterial mass but also near the colonies. Our results suggest that the microbial population contributed to phosphate precipitation by changing the media as a consequence of their metabolic activity. Moreover, the results of this research suggest that bacteria play an active role in the mineral precipitation of soluble phosphate from urban wastewater in submerged fixed-film bioreactors.This investigation was funded by the CTM 2009-11929-CO2-02 of the Spanish Ministerio de Educación y Ciencia

Erwinia mallotivora sp., a New Pathogen of Papaya (Carica papaya) in Peninsular Malaysia

Erwinia mallotivora was isolated from papaya infected with dieback disease showing the typical symptoms of greasy, water-soaked lesions and spots on leaves. Phylogenetic analysis of 16S rRNA gene sequences showed that the strain belonged to the genus Erwinia and was united in a monophyletic group with E. mallotivora DSM 4565 (AJ233414). Earlier studies had indicated that the causal agent for this disease was E. papayae. However, our current studies, through Koch’s postulate, have confirmed that papaya dieback disease is caused by E. mallotivora. To our knowledge, this is the first new discovery of E. mallotivora as a causal agent of papaya dieback disease in Peninsular Malaysia. Previous reports have suggested that E. mallotivora causes leaf spot in Mallotus japonicus. However, this research confirms it also to be pathogenic to Carica papaya

Sensitive and Specific Detection of Mycoplasma species by Consensus Polymerase Chain Reaction and Dot Blot Hybridization

Mycoplasmas are highly fastidious bacteria, difficult to culture and slow growing. Many species of mycoplasmas are important pathogens that cause respiratory infection in laboratory animals and that are known to affect experimental results obtained with contaminated animals. The aim of the present study was to develop a sensitive and specific assay for the detection of mycoplasma species. To this end, we developed a polymerase chain reaction and dot blot hybridization assay (PCR/DBH) for detecting mycoplasma DNA and evaluated it for its sensitivity and specificity. Mycoplasma consensus primer pairs were used for the amplification of target DNA. When PCR product was visually detected, the limit of detection of the PCR test was 102 pg of mycoplasma purified DNA. For DBH, the amplified DNA was labeled by incorporation of digoxigenin (DIG). This DIG-labeled probe was capable of detecting 104 pg of purified mycoplasma DNA by DBH. PCR/DBH was more sensitive than PCR or DBH alone and was also very specific. Our PCR/DBH assay can be applied efficiently to confirm the presence of mycoplasma species on clinical samples and to differentiate between mycoplasma species infection and other bacterial infections