An inventory of human night-biting mosquitoes and their bionomics in Sumba,Indonesia

Mosquitoes are important vectors that transmit pathogens to human and other vertebrates. Each mosquito species has specific ecological requirements and bionomic traits that impact human exposure to mosquito bites, and hence disease transmission and vector control. A study of human biting mosquitoes and their bionomic characteristics was conducted in West Sumba and Southwest Sumba Districts, Nusa Tenggara Timur Province, Indonesia from May 2015 to April 2018. Biweekly human landing catches (HLC) of night biting mosquitoes both indoors and outdoors caught a total of 73,507 mosquito specimens (59.7% non-Anopheles, 40.3% Anopheles). A minimum of 22 Culicinae species belonging to four genera (Aedes, Armigeres, Culex, Mansonia), and 13 Anophelinae species were identified. Culex quinquefasciatus was the dominant Culicinae species, Anopheles aconitus was the principal Anopheles species inland, while An. sundaicus was dominant closer to the coast. The overall human biting rate (HBR) was 10.548 bites per person per night (bpn) indoors and 10.551 bpn outdoors. Mosquitoes biting rates were slightly higher indoors for all genera with the exception of Anopheles, where biting rates were slightly higher outdoors. Diurnal and crepuscular Aedes and Armigeres demonstrated declining biting rates throughout the night while Culex and Anopheles biting rates peaked before midnight and then declined. Both anopheline and non-anopheline populations did not have a significant association with temperature (p = 0.3 and 0.88 respectively), or rainfall (p = 0.13 and 0.57 respectively). The point distribution of HBR and seasonal variables did not have a linear correlation. Data demonstrated similar mosquito–human interactions occurring outdoors and indoors and during early parts of the night implying both indoor and outdoor disease transmission potential in the area–pointing to the need for interventions in both spaces. Integrated vector analysis frameworks may enable better surveillance, monitoring and evaluation strategies for multiple diseases.     

Resistance of common carp (Cyprinus carpio L.) to Cyprinid herpesvirus-3 is influenced by major histocompatibility (MH) class II B gene polymorphism

The role of MH class II B (Cyca-DAB1-like) genes in resistance of common carp (Cyprinus carpio L.) to Cyprinid herpesvirus-3 (CyHV-3), also known as koi herpesvirus (KHV) was analysed. The material consisted of 934 fish from six carp crosses. Fish were challenged with CyHV-3 at an age of 7 and 10 months. During challenge experiments the peak of mortality caused by CyHV-3 was observed at days 8–12 p.i. and the overall cumulative mortality reached 79.9%. Among six Cyca-DAB1-like genotypes, revealed by PCR-RF-SSCP analysis, one genotype (E) was found associated with higher resistance to CyHV-3. Three other genotypes (B, H and J) could be linked to higher susceptibility to CyHV-3. Analysis of the alleles that compose the Cyca-DAB1-like genotypes linked one particular allele (Cyca-DAB1*05) to significantly increased, and two alleles (Cyca-DAB1*02 and Cyca-DAB1*06) to significantly decreased resistance to CyHV-3. Our data indicate that MH class II B genes could be used as potential genetic markers in breeding of common carp for resistance to this virus.     

Dietary Macrogard reduces <Emphasis Type="Italic">Aeromonas hydrophila</Emphasis> mortality in tench (<Emphasis Type="Italic">Tinca tinca</Emphasis>) through the activation of cellular and humoral defence mechanisms

Influence of beta-1.3/1.6-glucan (Macrogard) on the innate immunity and protection against Aeromonas hydrophila in tench (Tinca tinca (L.)) was assessed. Macrogard was fed at doses of 0, 0.5, 1 and 2 g kg⁻¹ of pellets for 1 month. The blood, spleen and head kidney from 10 fish of each group were separated and analysed for immunity parameters. Twenty tench from each group were infected with A. hydrophila. Macrogard at doses 1 and 2 g kg⁻¹ of feed significantly (P < 0.05) increased the phagocytic activity of macrophages and proliferative response of mitogens stimulated lymphocytes. The same doses significantly (P < 0.05) increased lysozyme activity and Ig level in serum, compared to the control and dose 0.5 g kg⁻¹ of feed. The challenge test showed that Macrogard reduced mortality of tench after experimental infection (5–35%).