Species Of Clinical Importance Research Articles

Candida metrosideri pro tempore sp. nov. and Candida ohialehuae pro tempore sp. nov., two antifungal-resistant yeasts associated with Metrosideros polymorpha flowers in Hawaii.

Flowers produce an array of nutrient-rich exudates in which microbes can thrive, making them hotspots for microbial abundance and diversity. During a diversity study of yeasts inhabiting the flowers of Metrosideros polymorpha (Myrtaceae) in the Hawai’i Volcanoes National Park (HI, USA), five isolates were found to represent two novel species. Morphological and physiological characterization, and sequence analysis of the small subunit ribosomal RNA (rRNA) genes, the D1/D2 domains of the large subunit rRNA genes, the internal transcribed spacer (ITS) regions, and the genes encoding the largest and second largest subunits of the RNA polymerase II (RPB1 and RPB2, respectively), classified both species in the family Metschnikowiaceae, and we propose the names Candida metrosideri pro tempore sp. nov. (JK22T = CBS 16091 = MUCL 57821) and Candida ohialehuae pro tempore sp. nov. (JK58.2T = CBS 16092 = MUCL 57822) for such new taxa. Both novel Candida species form a well-supported subclade in the Metschnikowiaceae containing species associated with insects, flowers, and a few species of clinical importance. The ascosporic state of the novel species was not observed. The two novel yeast species showed elevated minimum inhibitory concentrations to the antifungal drug amphotericin B (>4 μg/mL). The ecology and phylogenetic relationships of C. metrosideri and C. ohialehuae are also discussed.

Mycoplasmas are no exception to extracellular vesicles release: Revisiting old concepts.

Release of extracellular vesicles (EV) by Gram-negative and positive bacteria is being frequently reported. EV are nano-sized, membrane-derived, non-self-replicating, spherical structures shed into the extracellular environment that could play a role in bacteria-host interactions. Evidence of EV production in bacteria belonging to the class Mollicutes, which are wall-less, is mainly restricted to the genus Acholeplasma and is scanty for the Mycoplasma genus that comprises major human and animal pathogens. Here EV release by six Mycoplasma (sub)species of clinical importance was investigated. EV were obtained under nutritional stress conditions, purified by ultracentrifugation and observed by electron microscopy. The membrane proteins of EV from three different species were further identified by mass spectrometry as a preliminary approach to determining their potential role in host-pathogen interactions. EV were shown to be released by all six (sub)species although their quantities and sizes (30–220 nm) were very variable. EV purification was complicated by the minute size of viable mycoplasmal cells. The proteins of EV-membranes from three (sub)species included major components of host-pathogen interactions, suggesting that EV could contribute to make the host-pathogen interplay more complex. The process behind EV release has yet to be deciphered, although several observations demonstrated their active release from the plasma membrane of living cells. This work shed new light on old concepts of “elementary bodies” and “not-cell bound antigens”.

First Detection of Augmentin and Colistin Resistant <i>Cronobacter Sakazakii</i> from a Pharmaceutical Wastewater in South-Western Nigeria

Cronobacter sakazakii formerly known as Enterobacter sakazakii, is a bacterium with a rare cause but often fatal infection of the bloodstream and central nervous system. Infants with weakened immune systems, particularly premature infants, are most likely to contact a Cronobacter infection, although the bacteria have caused illnesses in all age groups. Most cases of C. sakazakii infection come from powdered infant formula (PIF) contaminated with the bacterium. Although relatively little information is known about the existence of Cronobacter in the environment, more reservoirs are being identified, such as water, soil and plant material. Wastewaters from 6 pharmaceutical industries located in a south-western state in Nigeria were sampled and analyzed. Bacteria were isolated using standard methods and species identification was determined by Gram staining, lactose fermentation, oxidase, catalase and Vitek 2. Antibacterial susceptibility to 25 antimicrobial agents was tested by the disc diffusion method and Vitek 2. Fifty nine Gram-negative bacteria were isolated and identified; one was identified as C. sakazakii. The bacterium was susceptible to all antibiotic mentioned but resistant to augmentin (amoxicillin/clavulanate) and colistin which are high potent drugs for the treatment of very stubborn infections. The public health implication of this fact is that this bacterium could be harbouring resistant genes that can be transferred through water ways such as the pharmaceutical wastewaters to bacteria of the same or different species of clinical importance. Therefore, continuous surveillance of the environmental reservoirs of antibiotic resistant bacteria is necessary to prevent their further spread.

Primary structures and partial toxicological characterization of two phospholipases A2 from Micrurus mipartitus and Micrurus dumerilii coral snake venoms

Snake venom phospholipases A2 (PLA2) share high sequence identities and a conserved structural scaffold, but show important functional differences. Only a few PLA2s have been purified and characterized from coral snake (Micrurus spp.) venoms, and their role in envenomation remains largely unknown. In this report, we describe the isolation, sequencing and partial functional characterization of two Micrurus PLA2s: MmipPLA2 from Micrurus mipartitus and MdumPLA2 from Micrurus dumerilii, two species of clinical importance in Colombia. MmipPLA2 consisted of 119 amino acid residues with a predicted pI of 8.4, whereas MdumPLA2 consisted of 117 residues with a pI of 5.6. Both PLA2s showed the conserved 'group I' cysteine pattern and were enzymatically active, although MdumPLA2 had higher activity. The two enzymes differed notably in their toxicity, with MmipPLA2 being highly lethal to mice and mildly myotoxic, whereas MdumPLA2 was not lethal (up to 3 μg/g body weight) but strongly myotoxic. MdumPLA2 displayed higher anticoagulant activity than MmipPLA2in vitro and caused more sustained edema in the mouse footpad assay. Neither of these enzymes was cytolytic to cultured skeletal muscle C2C12 myotubes. Based on their structural differences, the two enzymes were placed in separate lineages in a partial phylogeny of Micrurus venom PLA2s and this classification agreed with their divergent biological activities. Overall, these findings highlight the structural and functional diversity of Micrurus venom PLA2s.

Molecular epidemiology of human sporotrichosis in Venezuela reveals high frequency of Sporothrix globosa.

BackgroundSporotrichosis is a cutaneous and subcutaneous fungal disease of humans and other mammals, known to be caused by the Sporothrix schenckii species complex, which comprises four species of clinical importance: S. brasiliensis, S. globosa, S. luriei, and S. schenckii sensu stricto. Of them, S. globosa and S. schenckii s. str. show global distribution and differences in global frequency as causal agents of the disease. In the Americas, only three species are present: S. schenckii s. str., S. brasiliensis (so far, only reported in Brazil), and S. globosa. In Venezuela, since the first case of sporotrichosis reported in 1935, S. schenckii have been considered its unique etiological agent. In the present work, the presence of more than one species in the country was evaluated.MethodsBy phenotypic key features and molecular phylogeny analyses, we re-examined 30 isolates from diverse Venezuelan regions belonging to the fungi collection of Instituto de Biomedicina, Caracas, Venezuela, and national reference center for skin diseases. All isolates were collected between 1973 and 2013, and maintained in distilled water.ResultsSporotrichosis in Venezuela is mainly caused by S. schenckii s. str. (70%). However, a significant proportion (30%) of sporotrichosis cases in the country can be attributable to S. globosa. A correlation between intraspecific genotypes and clinical presentation is proposed.ConclusionsOur data suggest that sporotrichosis various clinical forms might be related to genetic diversity of isolates, and possibly, to diverse virulence profiles previously reported in the S. schenckii species complex. Sporothrix globosa was found to be the causative agent of 30% of sporotrichosis for the Venezuelan cases re-examined, the highest frequency of this species so far reported in the Americas. The high genetic variability presented by S. schenckii s. str. indicates that species distinction based on phenotypic key features could be a challenging and uncertain task; molecular identification should be always employed.

Effect of Bambusa tuldoides cv. ventricosa leaf extracted with fermented steep liquors of maize and sorghum on some pathogenic organisms

Aims: Bambusa tuldoides cv. ventricosa (bamboo) extract is used locally in the treatment of different types of fever in Africa. The extraction by cooking of fresh bamboo leaves using fermented steep liquor of ogi either made from maize or sorghum has been used traditionally in the treatment of Typhoid fever in the South-Western Nigeria. This work is designed to evaluate the antibacterial activity of the different fermented cereal (Zea mays and Sorghum bicolor) grains steep liquors as the extraction medium for the bamboo leaf in comparison with the ethanol extraction using agar well diffusion. Methodology and results: The extracted leaves (dried and fresh) from different fermented cereal steep liquors [maize (white and yellow) and sorghum (white and red)] media were screened for inhibition of some pathogenic species such as Staphylococcus aureus, Salmonella typhi, Streptococcus faecalis and Escherichia coli. The extracts were then tested at different concentrations for bacteriostatic activity towards these clinically-important species. The fresh leaf extracts from the fermented maize and sorghum liquors at a concentration of 20 g/100 mL showed antibacterial activities for all the tested bacteria, while the ethanolic leaf extract did not show any antibacterial activity for both S. typhi and S. faecalis. Higher concentration (20 g/ 40 mL) produced higher antibacterial activity in all the leaf extracts from the fermented maize and sorghum liquors. Conclusion, significance and impact study: Our data provide support for the traditional use of fermented maize and sorghum grill steep liquor extract of Bambusa tuldoides cv. ventricosa in treating the symptoms associated with the test organisms, in which the yellow maize liquor displayed greater antibacterial activity in comparison with the others.

DETERMINACIÓN DEL PERFIL DE ÁCIDOS GRASOS DE BACTERIAS DEL GÉNERO VIBRIO POR CROMATOGRAFÍA DE GASES

The genus Vibrio includes several species of clinical importance, many of them related to foodborne diseases. It is desirable to have alternative techniques to support the identification of bacterial genera and

Native New Zealand plants with inhibitory activity towards Mycobacterium tuberculosis

BackgroundPlants have long been investigated as a source of antibiotics and other bioactives for the treatment of human disease. New Zealand contains a diverse and unique flora, however, few of its endemic plants have been used to treat tuberculosis. One plant, Laurelia novae-zelandiae, was reportedly used by indigenous Maori for the treatment of tubercular lesions.MethodsLaurelia novae-zelandiae and 44 other native plants were tested for direct anti-bacterial activity. Plants were extracted with different solvents and extracts screened for inhibition of the surrogate species, Mycobacterium smegmatis. Active plant samples were then tested for bacteriostatic activity towards M. tuberculosis and other clinically-important species.ResultsExtracts of six native plants were active against M. smegmatis. Many of these were also inhibitory towards M. tuberculosis including Laurelia novae-zelandiae (Pukatea). M. excelsa (Pohutukawa) was the only plant extract tested that was active against Staphylococcus aureus.ConclusionsOur data provide support for the traditional use of Pukatea in treating tuberculosis. In addition, our analyses indicate that other native plant species possess antibiotic activity.

Antibiotic Activity of Aspergillus quadrilineatus Extracts Isolated From a Nigerian Cereal

Aspergillus quadrilineatus , isolated from the Nigerian cereal “acha”, demonstrated antibiotic activity in both static and submerged cultures of a variety of fungal and bacterial species of clinical importance. The time-course for the induction of antibiotic activity was determined, as well as the effects of different carbon sources, pH, temperature and bivalent cations.

Perturbation of laboratory test results by analytical interferences and drug effects

An account is given of ways in which drug treatment can influence the results of laboratory tests for certain species of clinical importance, and of methods of detecting such interferences or effects.

Prevalence of Ascariasis and Amebiasis in Cherokee Indian School Children

PIHYSICIANS at the Public Health Service Indian Hospital on the Cherokee North Carolina Indian Reservation diagnosed several cases of severe clinical ascariasis in children in 1964-65 and recorded the death of a child caused by what was believed to be an overwhelming infection with Ascaris lumnricoides. A preliminary survey in one part of the reservation in 1963 indicateld that 50 percent of the, children were infected with Ascaris worms. To determine the prevalence of the roundworm and other intestinal parasites in the Cherokee population, a collaborative study in 1965 between physicians at the hospital and the Parasitology Section of the National Communicable Disease Center, Public Hea.lth Service, was initiated. Because of logistical problems in obtaining specimens from persons living in the mountainous area of the reservation, it was decided to examine stool specimens from children attending the elementary school close to the hospital. Moreover, the 655 children in the elementary school would represent a sample of the approximately 5,000 residents of the reservation. More important, such examinations would indicate the prevalence of intestinal parasites in the group most likely to be affected by any species of clinical importance.