Production, purification, sequencing and activity spectra of mutacins D-123.1 and F-59.1.

Background: The increase in bacterial resistance to antibiotics impels the development of new anti-bacterial substances. Mutacins (bacteriocins) are small antibacterial peptides produced by Streptococcus mutans showing activity against bacterial pathogens. The objective of the study was to produce and characterise additional mutacins in order to find new useful antibacterial substances.

[Streptococcus mutans and oral streptococci in dental plaque].

The human oral microbial biota represents a highly diverse biofilm. Twenty-five species of oral streptococci inhabit the human oral cavity and represent about 20 % of the total oral bacteria. Taxonomy of these bacteria is complex and remains provisional.

Streptococcus salivarius mutants defective in mannose phosphotransferase systems show reduced sensitivity to mutacins I-T9 and R-3B.

Twenty-four mutacin-producing Streptococcus mutans strains were screened for their propensity to produce class II one-peptide bacteriocin using a deferred antagonism assay. Streptococcus salivarius and 3 mutants defective in their mannose phosphotransferase systems (mannose-PTS) were used as sensitive strains to identify which mannose-PTS could act as the docking site for class II one-peptide bacteriocin activity. We observed that only 2 strains of S.

Relationship between African dust carried in the Atlantic trade winds and surges in pediatric asthma attendances in the Caribbean.

Asthma is epidemic in developed and developing countries including those in the Caribbean where it is widely believed that African dust, transported in high concentrations in the Trade Winds every year, is a major causative factor. The link between asthma and dust in the Caribbean is based largely on anecdotal evidence that associates sharp increases in the occurrence of asthma symptoms with hazy conditions often caused by dust. Here we report on a 2-year study of the relationship between the daily concentrations of dust measured in on-shore Trade Winds at Barbados and pediatric asthma attendance rates at Queen Elizabeth Hospital (QEH).

An investigation of sources of Campylobacter in a poultry production and packing operation in Barbados.

Chicken meat is frequently contaminated with Campylobacter jejuni and is thought to be the major source of organisms causing human Campylobacter enteritis. Genotypic similarities between Campylobacter isolates from chicken meat at retail outlets and patients with gastroenteritis in Barbados suggested that it is a vehicle for infection of humans on the island and prompted this investigation of transmission of Campylobacter in a local poultry operation. Campylobacter testing was conducted at the hatchery, on the broiler farm and in the processing plant for two consecutive production cycles.

Isolation and genetic characterization of avian influenza viruses and a Newcastle disease virus from wild birds in Barbados: 2003-2004.

Zoonotic transmission of an H5N1 avian influenza A virus to humans in 2003-present has generated increased public health and scientific interest in the prevalence and variability of influenza A viruses in wild birds and their potential threat to human health. Migratory waterfowl and shorebirds are regarded as the primordial reservoir of all influenza A viral subtypes and have been repeatedly implicated in avian influenza outbreaks in domestic poultry and swine. All of the 16 hemagglutinin and nine neuraminidase influenza subtypes have been isolated from wild birds, but waterfowl of the order Anseriformes are the most commonly infected.

Bacteriocin-like inhibitory substances from Campylobacter spp.

Twenty-five Campylobacter isolates were screened for production of antimicrobial substances using a deferred antagonism assay. Sixteen isolates showed activity against either Staphylococcus aureus, Salmonella enterica serovar Enteritidis or Candida albicans. The inhibitory activity was sensitive to treatment with pronase E, trypsin and pepsin, suggesting that the antimicrobial compound(s) are proteinaceous.

Mutacin H-29B is identical to mutacin II (J-T8).

Background: Streptococcus mutans produces bacteriocins named mutacins. Studies of mutacins have always been hampered by the difficulties in obtaining active liquid preparations of these substances. Some of them were found to be lantibiotics, defined as bacterial ribosomally synthesised lanthionine-containing peptides with antimicrobial activity.

Human Campylobacter-associated enteritis on the Caribbean island of Barbados.

A longitudinal study of the incidence of Campylobacter enteritis in Barbados was undertaken from January 2000 to August 2003. Diarrheal stools received by the central public health laboratory were cultured for Campylobacter. The number of reported Campylobacter cases exceeded those of Shigella but were less than those of Salmonella, and increased steadily with each year.

Identification of Streptococcus iniae by commercial bacterial identification systems.

The fish pathogen Streptococcus iniae cannot be identified by most commercial bacterial identification systems. The results presented here indicate that over 70% of our S. iniae isolates have been identified using the Biolog(R) GP microplate panels and Microlog(R) database.

In vivo activity of mutacin B-Ny266.

Objectives: The objective of this study was to assess the in vivo activity of mutacin B-Ny266 (a bacteriocin produced by Streptococcus mutans) in order to eventually use it as an antibiotic.

Methods: Intraperitoneal infection was induced with a methicillin-susceptible Staphylococcus aureus strain in mice. Some of the mice were simultaneously injected intraperitoneally with mutacin B-Ny266, some with the vehicle only and some with vancomycin.

Pet dogs and chicken meat as reservoirs of Campylobacter spp. in Barbados.

Campylobacter spp. are the second most common pathogen isolated from stools of patients with gastroenteritis in Barbados. The aim of this study was to identify reservoirs of Campylobacter and the likely source(s) of human infection.

Improved methods for mutacin detection and production.

Studies of mutacins have always been hampered by the difficulties in obtaining active liquid preparations of these substances. In order to be commercially produced, good mutacin yields have to be obtained, preferably in inexpensive media. The results presented here indicate that mutacins can be produced in supplemented cheese whey permeate.

Replacement of trifluoroacetic acid with HCl in the hydrophobic purification steps of pediocin PA-1: a structural effect.

Trifluoroacetic acid (TFA) is a purification contaminant associated with pediocin PA-1 that interferes with Fourier transform infrared spectroscopy structural analysis. As revealed by circular dichroism, its presence affects the structural folding of pediocin. Consequently, we propose a new pediocin PA-1 purification procedure using HCl instead of TFA in all of the hydrophobic steps.

Diversity of Streptococcus mutans bacteriocins as confirmed by DNA analysis using specific molecular probes.

Mutacin-producing strains have been classified into 24 groups (designated by letters A to X) by similarity in activity spectra and cross-immunity. Similarity in primary structure among these groups can be revealed using DNA hybridization. The amino acid sequences of four mutacins (B-Ny266, 1140/mutacin III and mutacin II) were used to design two DNA probes in order to detect similar genes among groups of Streptococcus mutans strains demonstrating inhibitory activity.