Occurrence and genetic relatedness of Listeria spp. in two brands of locally processed ready-to-eat meats in Trinidad.

Contamination of locally produced, ready-to-eat meats by Listeria spp. has been previously reported at one processing plant in Trinidad. However, the status of this pathogen in locally produced products sold at retail outlets is unknown. This study was conducted to establish whether there is a risk to consumers of locally processed meats caused by the presence of Listeria spp., and whether a link exists between the presence of the pathogen in retail products and the manufacturing plant of one brand (B). Four hundred and eighty ready-to-eat meat products of two popular local brands (A and B) were collected from retail outlets and analysed for the presence of Listeria spp. together with food samples and surfaces from one manufacturing plant (B). Eighty-eight of the retail products (18·3%) were contaminated with Listeria spp., of which, 52·3% were L. innocua, 44·3% were L. monocytogenes and 3·4% belonged to the L. seeligeri-L. welshimeri-L. ivanovii (Siwi) group. L. innocua was found in 15 in-process food samples and on three surfaces of equipment at plant B. Four in-process food samples were also contaminated with Siwi isolates. Repetitive extragenic palindromic PCR DNA fingerprinting showed a possible association between strains of different Listeria spp. and brand as well as with manufacturing plant B.

Prevalence of bacterial pathogens and their anti-microbial resistance in Tilapia and their pond water in Trinidad.

In Trinidad, Tilapia (Oreonchromis spp.) is one of the most important fresh water food fish and the number of farms has been increasing annually. A study was conducted in the local tilapia industry to determine the microbial quality of pond water, prevalence of bacterial pathogens and their anti-microbial resistance using the disk diffusion method. Seventy-five apparently healthy fish and 15 pond water samples from three of the four commercial tilapia fish farms in the country were processed. The 202 bacterial isolates recovered from fish slurry and 88 from water, belonged to 13 and 16 genera respectively. The predominant bacteria from fish slurry were Pseudomonas spp. (60.0%), Aeromonas spp. (44.0%), Plesiomonas (41.3%) and Chromobacterium (36.0%) (P < 0.05; chi(2)) compared with isolates from pond water where Bacillus spp. (80.0%), Staphylococcus spp., Alcaligenes spp. and Aeromonas spp. (60.0%) were most prevalent (P < 0.05; chi(2)). Using eight anti-microbial agents, to test bacteria from five genera (Aeromonas, Chromobacterium, Enterobacter, Plesiomonas and Pseudomonas), 168 (97.1%) of 173 bacterial isolates from fish slurry exhibited resistance to one or more anti-microbial agents compared with 47 (90.4%) of 52 from water (P > 0.05; chi(2)). Resistance was high to ampicillin, 90.2% (158 of 173), erythromycin, 66.5% (115 of 173) and oxytetracycline, 52.6%, (91 of 173) but relatively low to chloramphenicol, 9.8% (17 of 173) and sulphamethoxazole/trimethoprim, 6.4% (11 of 173) (P < 0.05; chi(2)). For pond water isolates, the frequency of resistance across bacterial genera ranged from 75% (nine of 12) for Chromobacter spp. to 100% found amongst Enterobacter spp. (six of six), Plesiomonas spp. (nine of nine) and Pseudomonas spp. (eight of eight) (P < 0.05; chi(2)). Resistance was generally high to ampicillin, 78.8% (41 of 52), erythromycin, 51.9% (27 of 52) and oxytetracycline, 34.5% (18 of 52) but low to sulphamethoxazole/trimethoprim, 7.7% (four of 52) and norfloxacin, 3.8% (two of 52) (P < 0.05; chi(2)). It was concluded that the rather high prevalence of bacterial pathogens in tilapia along with their high prevalence of resistance to anti-microbial agents might pose therapeutic problems as well as health risk to consumers. The microbial presence and their anti-microbial resistance in the tilapia industry are being reported for the first time in the country.

Investigation of wound healing activity of Lantana camara L. in Sprague dawley rats using a burn wound model.

Summary: Lantana camara is used in herbal medicine for the treatment of skin itches, as an antiseptic for wounds, and externally for leprosy and scabies. The objective of our study is to investigate burn wound healing activity of the leaf extract of L.camara in rats. The animals were divided into two groups of 6 each. The test group animals were treated with the ethanol extract of L. camara (100 mg kg-1 day-1) topically and the control group animals were left untreated. Healing was assessed by the rate of wound contraction, period of epithelialization. Antimicrobial activities of the extract against the specific microorganisms were assessed. The extract showed antimicrobial activity against Staphylococcus aureus, Klebsiella Pneumoniae and E.coli. Extract treated wounds were healed in about 21 days which is not distinct from the controls. Our data suggest that L.camara has antimicrobial activity but not wound healing promoting activity on burn wound. Industrial relevance: Extensive work has been done on the L. camara and demonstrated the antimicrobial and fungicidal activity of its chemical constituents. Lantana oil is used for the treatment of skin itches and as an antiseptic for wounds. It has been used in folk medicine for the treatment of cancers, chicken pox, measles, ulcers, swellings, eczema. Our earlier work showed the healing activity on excision wound model. However, there is no data to support the wound healing activity of L. camara on burn wound. Hence, we have conducted the present study to explore the wound healing activity and the antimicrobial activities of L. camara against the specific microorganisms which generally infect burn wound.

Prevalence of bacterial pathogens and their anti-microbial resistance in Tilapia and their pond water in Trinidad.

In Trinidad, Tilapia (Oreonchromis spp.) is one of the most important fresh water food fish and the number of farms has been increasing annually. A study was conducted in the local tilapia industry to determine the microbial quality of pond water, prevalence of bacterial pathogens and their anti-microbial resistance using the disk diffusion method. Seventy-five apparently healthy fish and 15 pond water samples from three of the four commercial tilapia fish farms in the country were processed. The 202 bacterial isolates recovered from fish slurry and 88 from water, belonged to 13 and 16 genera respectively. The predominant bacteria from fish slurry were Pseudomonas spp. (60.0 per cent), Aeromonas spp. (44.0 per cent), Plesiomonas (41.3 per cent) and Chromobacterium (36.0 per cent) (P < 0.05; chi(2)) compared with isolates from pond water where Bacillus spp. (80.0 per cent), Staphylococcus spp., Alcaligenes spp. and Aeromonas spp. (60.0 per cent) were most prevalent (P < 0.05; chi(2)). Using eight anti-microbial agents, to test bacteria from five genera (Aeromonas, Chromobacterium, Enterobacter, Plesiomonas and Pseudomonas), 168 (97.1 per cent) of 173 bacterial isolates from fish slurry exhibited resistance to one or more anti-microbial agents compared with 47 (90.4 per cent) of 52 from water (P > 0.05; chi(2)). Resistance was high to ampicillin, 90.2 per cent (158 of 173), erythromycin, 66.5 per cent (115 of 173) and oxytetracycline, 52.6 per cent, (91 of 173) but relatively low to chloramphenicol, 9.8 per cent (17 of 173) and sulphamethoxazole/trimethoprim, 6.4 per cent (11 of 173) (P < 0.05; chi(2)). For pond water isolates, the frequency of resistance across bacterial genera ranged from 75 per cent (nine of 12) for Chromobacter spp. to 100 per cent found amongst Enterobacter spp. (six of six), Plesiomonas spp. (nine of nine) and Pseudomonas spp. (eight of eight) (P < 0.05; chi(2))...

Antibiotic-resistance patterns of bacterical pathogens isolated from ornamental fish in Trinidad and Tobago

Ornamental fish farming forms an important part of the local aquaculture industry in Trinidad and Tobago, and the number of farms has been increasing annually. This study was designed to ascertain the prevalence of bacterial pathogens from fish and pond water, and determine the resistance of the bacteria to commonly used antimicrobial agents. A total of 1204 bacterial isolates were recovered: from 575 fish slurry and 111 water samples from 17 aquaculture farms. Isolates from fish were identified as belonging to 19, and those from water samples were grouped in 18 genera. The predominant genera isolated were (in descending order) Aeromonas spp., Pseudomonas spp., Plesiomonas spp., Chromobacterium spp., Enterobacter spp. and Serratia spp. Screening against 8 antimicrobial agents showed that 95.1 percent (774 of 814) of isolates from fish slurry, and 98.4 percent (254 to 258) of isolates from pond water were resistant to one or more antimicrobial agents ( P> 0.05, X2). The highest resistance (55-94 percent) were to ampicillin, oxytetracycline and erythromycin, but relatively lower resistance (4-14 percent) occurred to gentamycin and norfloxacin (P< 0.05; X2). It was concluded that the high prevalence of bacterial pathogens in ornamental fish coupled with their high levels of resistance to antimicrobial agents may pose therapeutic problems as well as health risks to farmers, workers and fish hobbyists

Bacillus subtilis AB1 controls Aeromonas infection in rainbow trout (Oncorhynchus mykiss, Walbaum).

AIM: To develop a probiotic with effectiveness against Aeromonas sp., which was pathogenic to rainbow trout. METHODS AND RESULTS: When Bacillus subtilis AB1, which was obtained from fish intestine, was administered for 14 days to rainbow trout in feed at a concentration of 10(7) cells per gram either as viable, formalized or sonicated cells or as cell-free supernatant, the fish survived challenge with the pathogen. AB1 stimulated immune parameters, specifically stimulating respiratory burst, serum and gut lysozyme, peroxidase, phagocytic killing, total and alpha1-antiprotease and lymphocyte populations. CONCLUSIONS: Bacillus subtilis AB1 was effective as a probiotic at controlling infections by a fish-pathogenic Aeromonas sp. in rainbow trout. SIGNIFICANCE AND IMPACT OF THE STUDY: Disease control in fish is possible by means of the oral application of live and inactivated cells and their subcellular components with the mode of action reflecting stimulation of the innate immune response.

Bacillus subtilis AB1 controls Aeromonas infection in rainbow trout (Oncorhynchus mykiss, Walbaum).

AIM: To develop a probiotic with effectiveness against Aeromonas sp., which was pathogenic to rainbow trout. METHODS AND RESULTS: When Bacillus subtilis AB1, which was obtained from fish intestine, was administered for 14 days to rainbow trout in feed at a concentration of 10(7) cells per gram either as viable, formalized or sonicated cells or as cell-free supernatant, the fish survived challenge with the pathogen. AB1 stimulated immune parameters, specifically stimulating respiratory burst, serum and gut lysozyme, peroxidase, phagocytic killing, total and alpha1-antiprotease and lymphocyte populations. CONCLUSIONS: Bacillus subtilis AB1 was effective as a probiotic at controlling infections by a fish-pathogenic Aeromonas sp. in rainbow trout. SIGNIFICANCE AND IMPACT OF THE STUDY: Disease control in fish is possible by means of the oral application of live and inactivated cells and their subcellular components with the mode of action reflecting stimulation of the innate immune response.

Saharan dust - a carrier of persistent organic pollutants, metals and microbes to the Caribbean? / Polvo sahariano: ¿portador de contaminantes orgánicos persistentes, metales y microbios al Caribe?

An international team of scientists from government agencies and universities in the United States, U.S. Virgin Islands (USVI), Trinidad & Tobago, the Republic of Cape Verde, and the Republic of Mali (West Africa) is working together to elucidate the role Saharan dust may play in the degradation of Caribbean ecosystems. The first step has been to identify and quantify the persistent organic pollutants (POPs), trace metals, and viable microorganisms in the atmosphere in dust source areas of West Africa, and in dust episodes at downwind sites in the eastern Atlantic (Cape Verde) and the Caribbean (USVI and Trinidad & Tobago). Preliminary findings show that air samples from Mali contain a greater number of pesticides, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) and in higher concentrations than the Caribbean sites. Overall, POP concentrations were similar in USVI and Trinidad samples. Trace metal concentrations were found to be similar to crustal composition with slight enrichment of lead in Mali. To date, hundreds of cultureable micro-organisms have been identified from Mali, Cape Verde, USVI, and Trinidad air samples. The sea fan pathogen, Aspergillus sydowii, has been identified in soil from Mali and in air samples from dust events in the Caribbean. We have shown that air samples from a dust-source region contain orders of magnitude more cultureable micro-organisms per volume than air samples from dust events in the Caribbean, which in turn contain 3-to 4-fold more cultureable microbes than during non-dust conditions. Rev. Biol. Trop. 54 (Suppl. 3): 9-21. Epub 2007 Jan. 15.

Un grupo internacional de agencias gubernamentales y universidades de los Estados Unidos, las Islas Vírgenes (EUA), Trinidad y Tobago, la República de Cabo Verde y la República de Mali (África Oeste), está trabajando en conjunto para elucidar el papel que el polvo del Sahara puede estar jugando en el deterioro de los ecosistemas caribeños. El primer paso ha sido identificar y cuantificar los Contaminantes Orgánicos Persistentes (POPs, por sus siglas en inglés), los metales traza y los microorganismos viables presentes en la atmósfera de las áreas fuente de polvo de África occidental y en áreas ubicadas en la dirección del viento, como el Atlántico este (Cabo Verde) y el Caribe (IVEUA y Trinidad y Tobago), durante los episodios de transporte de polvo. Resultados preliminares indican que las muestras de aire de Mali contienen mayor número y mayores concentraciones de pesticidas, bifenilos policlorinados (PCBs) e hidrocarburos policíclicos aromáticos (PAHs) que las de los sitios del Caribe. Las concentraciones de POPs fueron similares en las muestras de USVI y de Trinidad. Se encontró que las concentraciones de metales traza fueron similares a las de la composición de la corteza, con un ligero enriquecimiento de plomo en Mali. Hasta la fecha, cientos de microorganismos cultivables han sido identificados en las muestras de Mali, Cabo Verde, IVEUA y Trinidad. Hallamos el patógeno de los abanicos de mar, Aspergillus sydowi, en las muestras de aire de Mali y en las muestras del Caribe durante polvaredas. Hemos demostrado que las muestras de aire provenientes de una región fuente de polvo, contienen más microorganismos cultivables por volumen -en órdenes de magnitud- que las muestras de aire tomadas en polvaredas en el Caribe, las cuales a su vez contienen tres a cuatro veces más microorganismos cultivables que aquellas tomadas cuando no hay polvaredas.