Antimicrobial resistance and toxigenic profiles of bacteria isolated from tropical shrimps (Farfantepenaeus notialis and Penaeus monodon) in Cameroun.

OBJECTIVE: Post-harvest shrimp losses are a big problem due to the proliferation of spoilage bacteria. Presence and multiplication of these bacteria promotes the emergence of food-borne diseases. This study was carried out to characterize some spoilage bacteria from tropical brackish water shrimps and black tiger shrimps stored in ambient temperature (25 °C). RESULTS: 22 isolates of Bacillus spp; 09 isolates of Coagulase Negative Staphylococci (CNS) and 04 isolates of enterobacteria such as Pantoea spp (01); Serratia plymutica (01) and Serratia rubidaea (02) have been identified. Resistance and virulence genes were then detected. All isolates expressed resistance to at least three of antibiotics tested. 03 isolates of enterobacteria were susceptible to cetfazidim and amoxicillin-clavulanic acid. Bacillus spp showed total susceptibility to cefixim, ertapenem and cetfazidim. Staphylococci were susceptible to clindamycin. Pantoea spp was resistant to all antibiotics but exhibited intermediate susceptibility to amoxicillin-clavulanic acid. 04 isolates of Staphylococci were positive to mecA resistances genes. All the enterobacteria harbor no tetracycline resistance genes. All the isolates of Bacillus exhibited the presence of enterotoxin genes. Also, a high prevalence of 21 isolates to hemolytic enterotoxins was noted. 17 isolates from them kept ability to cell-lyse factor production like sphingomyelinase activities. The majority of Bacillus isolates identified by the present study poses a potential risk of food poisoning due to the prevalence of toxin genes found.

Prevalence of cattle trypanosomosis in slaughterhouses and farms in Benin and impact on hematocrit in cattle.

OBJECTIVE: The present study aimed to determine the prevalence of bovine trypanosomosis in Benin. MATERIALS AND METHODS: For this purpose, the blood samples were taken from 932 cattle: 573 from slaughterhouses and 359 from the farms of the targeted divisions. After the blood samples, thick drops and blood smears were made. The capillary tubes filled with blood made it possible to determine the hematocrit in cattle. RESULTS: The prevalence of trypanosomosis in farms (27.02%) was significantly higher (p < 0.001) than that of animals in slaughterhouses (16.75%). In farms, the prevalence was 38.55% during the rainy season against 16.67% in the dry season (p < 0.001). In slaughterhouses, prevalences were 10.99%, 17.58%, and 21.50%, respectively, in Bohicon, Cotonou/Porto-Novo, and Parakou. Hematocrit in slaughterhouses was 24.17% and 31.44%, respectively, in infested and non-infested animals. In farms, this rate was 22.85% in infested animals and 29.31% in non-infested animals (p < 0.05). Young cattle are more vulnerable to trypanosomosis than older cattle. CONCLUSION: Given the endemic situation of bovine trypanosomosis and its impact on the economy, this knowledge of the health status of cattle will help out to seek ways and alternatives to reduce the damage.

Evaluation of in-vivo anti-Salmonella activity of Uvaria chamae, Lantana camara and Phyllantus amarus used in Benin, West Africa.

BACKGROUND: Uvaria chamae (Annonaceae), Phyllantus amarus (Phyllantaceae) and Lantana camara (Verbenaceae) are empirically alleged to be used as Beninese medicinal plants in the treatment of salmonellosis. This study aimed to produce scientific data on in vitro and in vivo efficacy of Uvaria chamae, Lantana camara and Phyllantus amarus on multiresistant Salmonella spp isolated in Benin. RESULTS: After performing in vitro tests on aqueous and ethanolic extracts of these plants, only the aqueous extract of Uvaria chamae (leaves) showed the best anti-Salmonella's activity and was used for this in vivo experiment. The induction of salmonellosis revealed 9 × 108 CFU/ml was the optimal concentration triggering and maintaining symptoms in chicks. This infective concentration was used for in vivo assessment. Twenty-four hours post inoculation, the symptoms of salmonellosis (wet cloaca, diarrhea stools and somnolence) were observed in infected groups. After 7 days of treatment, the reduction of bacterial load at 100 mg/L, 200 mg/L, 400 mg/L of the extract was respectively 85%, 52.38% and 98% for Uvaria chamae, Phyllantus amarus and Lantana camara in the chick's groups infected with Salmonella Typhimurium ATCC 14028. On the other hand, colistin completely cancelled the bacterial load (reduction rate of 100%). With the groups infected with Salmonella spp (virulent strain), the reduction rate of bacterial load at 100 mg/L, 200 mg/L, 400 mg/L of extract was 0%, 98.66%, and 99.33%. The extracts at 200 and 400 mg/L were more active than colistin, which reduced the bacterial load by 33.33%. The toxicity tests did not show any negative effect of Colistin and the Uvaria chamae's extract on the biochemical and hematological parameters of the chicks. CONCLUSION: The aqueous extract of Uvaria chamae is active in vitro and in vivo on multiresistant strains of Salmonella enterica. This plant is a good candidate for the development of an improved traditional medicine for the management of salmonellosis.

Toxicological Characterization of Six Plants of the Beninese Pharmacopoeia Used in the Treatment of Salmonellosis.

Recent studies reported interesting ethnopharmacological, antibacterial, and phytochemical data on some medicinal plants used in the traditional treatment of salmonellosis in Benin. Unfortunately, very little data exists on the toxicity of these species. This study aims to evaluate chemical characteristic of six Benin pharmacopoeial plants used in the traditional treatment of salmonellosis in Benin. The acute toxicity of aqueous and ethanolic extracts of Psidium guajava, Vernonia amygdalina, Cajanus cajan, Phyllanthus amarus, Uvaria chamae, and Lantana camara was evaluated according to OECD Guideline 423 at a single dose of 2000 mg/kg body weight on Wistar rats. Histological sections were performed on the liver and kidneys to confirm hematological and biochemical data. The content of aluminum, chromium, cadmium, copper, iron, lead, zinc, arsenic, selenium, and manganese was measured in 10 mg of each extract by the inductively coupled plasma optical emission spectroscopy (ICPOES) method. The results of our study generally show the absence of significant effect of the extracts on the hematological and biochemical parameters of the rats. However, with the exception of the aqueous and ethanolic extracts of Psidium guajava root and the ethanolic extract of Phyllanthus amarus (P>0.05), all the extracts have a significant effect on the aspartate aminotransferase (ASAT) level, with a variable threshold of significance (0.0001< P ≤ 0.05). No mortalities and no renal histological conditions were recorded in the treated rats. In general, the heavy metal contents of the extracts do not exceed the standards set by the WHO/FDA except for a few extracts. Arsenic was not detected in any extract, while aluminum and chromium were detected at levels above the WHO/FDA standards. On the basis of these data, it appears that the six plants studied do not show any toxicity. In view of the pharmacological and chemical data previously available, these plants are good candidates for the development of improved traditional medicines with antibacterial and particularly anti-Salmonella properties.

Resistance and virulence determinants of faecal Salmonella spp. isolated from slaughter animals in Benin.

OBJECTIVE: Salmonella spp. are one of the leading foodborne pathogens worldwide naturally found in the intestines of many animals. People that are in direct contact with the infected animals or their cages may become ill. The aim of this study was to determine the prevalence, antibiogram and virulence genes associated with Salmonella serovars from fecal samples of animals intended for consumption in Southern Benin. RESULTS: Out of a total of 406 samples, 2.46% were positive. The isolates identified were multidrug-resistant Salmonella spp. to penicillins, first generation cephalosporins and some aminoglycosides. All Salmonella isolates produced invA gene of 284 bp, fimA of 85 bp and stn of 260 bp. The spvC gene (571 bp) was present in 10% of the isolates whereas the spvR gene (310 bp) was found in 20% of the isolates. The control strain possessed all the tested genes. The invA gene implies that strains are able to invade epithelial cells. The fimA and stn genes present in all isolates show that they are capable of causing gastrointestinal illness in humans. The presence of spvC and spvR genes suggests the possibility of these strains to produce toxins.

[Presence of lead in leaves of Solanum macrocarpon cultivated in Cotonou (Benin): role of poorly composted poultry manure]. / Présence du plomb dans les feuilles de Solanum macrocarpon Linn cultivé à Cotonou (Bénin) : rôle des fientes de poulets mal compostées.

This work assesses the impact of the use of chicken manure and irrigation water on the toxicological quality of Solanum macrocarpon, a highly appreciated vegetable. A control site in Glo-Djigbé, gardeners' sites at Houéyiho, Fidjrossè, and Agongbomey were included in the study. Lead has been sought in the environment of S. macrocarpon culture by Atomic Absorption Spectrophotometry (AAS). Regarding the content of lead in the droppings, the averages in mg/kg varied between 0.696 and 3.618. The soil of Houéyiho (46.320±0.651mg/kg) was more contaminated with lead than that of the other sites. The irrigation water used in the study sites was slightly contaminated with lead with values ranging between 0.038 and 0.017mg/L. Leaves taken from the control site, Glo-Djigbé were contaminated with lead with a value of 0.936±0.070mg/kg compared to those of Agongbomey, Houéyiho and Fidjrossè. The leaves of S. macrocarpon were contaminated with lead at significantly values higher than those imposed by the FAO (0.1mg/kg). Consumption without precautions could expose people to diseases related to the accumulation of this metal.