First report of paralytic shellfish poisoning (PSP) caused by Alexandrium tamiyavanichii in Kuantan Port, Pahang, East Coast of Malaysia

Abstract

SUMMARY Harmful algal bloom (HAB) is a proliferation of algae, which naturally produce biotoxins and cause harmful effects to humans, the environment and organisms associated with it. Paralytic shellfish poisoning (PSP) was reported for the first time in Kuantan Port, Pahang, Malaysia, in November 2013, followed by a second episode in August 2014. The toxicity level reported during the second event was as high as 3500 μg of STX equiv./100 g shellfish. Ten people were hospitalized with PSP symptoms after consuming contaminated shellfish. This study was conducted at Kuantan Port to identify the organisms responsible for these events. Water samples were collected monthly for a period of 12 months beginning in September 2014. HAB species were identified based on their morphology using light and fluorescence microscopes, and their classification was supported by molecular evidence based on internal transcribed spacer (ITS) sequences. Monthly cell abundance of Alexandrium tamiyavanichii was measured at four sampling stations. Toxin production by three strains isolated from the area was determined using HPLC. Our results revealed the presence of several HAB species, including the PSP‐producing species A. tamiyavanichii. The highest cell density of A. tamiyavanichii was 840 cells L−1. The presence of GTX components was detected in these strains. However, other toxin components could not be determined. This study reported, for the first time, the presence of PSP‐producing A. tamiyavanichii on the Pahang coast of east Peninsular Malaysia and confirmed that the PSP events in Kuantan Port were attributable to this species. The presence of this species further indicates that several safety measures need to be considered to safeguard public health, particularly in Pahang coastal waters.

Molecular Identification and Toxin Analysis of Alexandrium spp. in the Beibu Gulf: First Report of Toxic A. tamiyavanichii in Chinese Coastal Waters

“…We detected only GTX1-5 and STX toxins in the Beibu Gulf strain, which is similar to the PSTs composition of the Chula 6 strains from Thailand and the KOSKP01, KOSKP02, and KOSKP03 strains from Malaysia [ 38 , 47 , 57 ], but different from other A. tamiyavanichii strains from these countries as well as strains from Japan, Brazil, and South Africa ( Table 3 ). The range in PST content of A. tamiyavanichii reported in the literature is 1.17 fmol/cell–3.07 × 10 6 fmol/cell.…”

A Review of Published Literature Regarding Health Issues of Coastal Communities in Sabah, Malaysia

“…PSP is also common in the coastal areas of Malaysia. Based on the national report, more than a hundred of cases of PSP occur annually in Sabah, Sarawak, Malacca, and Penang states [40,41]. PSP cases are predominantly associated with harmful algal bloom, which is a natural phenomenon where the density of microalgal species in both marine and freshwater environments increases due to physiological alteration and rapid growth of the species, resulting in the accumulation of algal-origin toxins in shellfish [40].…”

“…Incomprehensive law enforcement and insufficient monitoring development activities such as industrialisation and urbanisation that lead to eutrophication of the coastal waters are the major contributors for the incidence of poisoning particularly at the remote coastal areas in Sabah that are highly polluted such as in Kudat [42]. Additionally, legislation of food acts, national surveillance, public awareness programmes, and the development of national guidelines on the appropriate preparation of marine products for consumption are essential to control the disease, resulting in an improved well-being of the coastal communities [39][40][41]. Preparing and cooking of affected seafood products require a specific technique, and most individuals have insufficient knowledge regarding this technique.…”

MITIGATION OF TOXIC Alexandrium tamiyavanichii USING CHITOSAN-SILICA COMPOSITE

“…This caused an economic problem for the breeders [2]. The second case was in Kuantan Port, Pahang where ten people were hospitalized [3]. The occurrence of this species and other HAB species indicate that HABs are a serious problem that require further attention, especially as it affects human and the ecosystem, as evidenced by the negative impact to fisheries and tourism industries.…”