Faecal Contaminants in Edible Bivalves from Maputo Bay, Mozambique: Seasonal Distribution, Pathogenesis and Antibiotic Resistance

Abstract

Abstract:In Maputo, Mozambique marine bivalves considerably contribute to the diet of the population. This study aimed to investigate seasonal distribution of Escherichia coli and Salmonella in clams from Maputo Bay, and examine their pathogenesis and antibiotic-resistant patterns. Standard multiple tube method revealed that the concentration of coliforms in all samples exceeded the limit for direct consumption, according to EU standards. Thirty-eight percent of the samples contained >60,000 MPN per 100 gram flesh. The occurrence of E. coli did not differ significantly due to season, while Salmonella was present in 100% of the samples during the rainy period and only in 30% during the dry. Multiplex polymerase chain reaction showed that 45% of E. coli isolates were positive for the virulent indicator gene fimA. The Salmonella isolates were identified as S. enterica serovar Typhimurium. Among other isolated coliformic Enterobacteriaceae, Shigella sp. (specie), which in low doses can cause severe gastrointestinal infections, was identified. Antimicrobial susceptibility, recorded by the disk diffusion method, showed resistance to the most commonly used antibiotics. This high levels of faecal contaminants in the clams points out the need for risk assessment and sanitary improvements.

Comparative Study on Faecal Contamination and Occurrence of Salmonella spp. and Vibrio parahaemolyticus in Two Species of Shellfish in Morocco

“…However, in clams from Mozambique, the prevalence of this pathogen was very high with 75.7% of samples with a difference between dry season (when three on eleven samples were positive) and wet period where all samples (n=22) were positive for Salmonella [10]. On other study done on mussels and Donax spp in Albania, prevalence of Salmonella was 0.2% out of 458 examined samples of bivalves, although the majority of the studied points are of class B [11].…”

Characteristics of potentially pathogenic vibrios from subtropical Mozambique compared with isolates from tropical India and boreal Sweden

“…A similar seasonal distribution of viable enterobacteria in clams from Maputo Bay was previously reported by Collin et al . (). During the rainy season, the water temperature was c .…”

“…In addition, a number of isolates from India and Sweden were resistant to additional antibiotics, such as chloramphenicol, cefuroxim, and nalidixic acid. Environmental V. parahaemolyticus strains from Maputo have been studied before, with the results indicating a spread in antibiotic resistance (Taviani et al ., ), as has also been seen in other bacteria in the area (Collin et al ., ). Elsewhere in Mozambique, Ansaruzzaman et al .…”

Sustainable Planning of a New City in Mozambique

“…Main problems concern turbidity, dissolved oxygen, and nutrients (ARA-Sul, 2010). In the estuary and Maputo Bay the water quality is degraded by human activities (Sete et al, 2002;Collin et al, 2008).…”