@article{fdi:010060708,
  title = {{M}ultiple insecticide resistance mechanisms in {A}nopheles gambiae s.l. populations from {C}ameroon, {C}entral {A}frica},
  author = {{N}wane, {P}. and {E}tang, {J}. and {C}houaibou, {M}. and {T}oto, {J}. {C}. and {K}offi, {A}. and {M}impfoundi, {R}. and {S}imard, {F}r{\'e}d{\'e}ric},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground: {I}ncreasing incidence of {DDT} and pyrethroid resistance in {A}nopheles mosquitoes is seen as a limiting factor for malaria vector control. {T}he current study aimed at an in-depth characterization of {A}n. gambiae s.l. resistance to insecticides in {C}ameroon, in order to guide malaria vector control interventions. {M}ethods: {A}nopheles gambiae s.l. mosquitoes were collected as larvae and pupae from six localities spread throughout the four main biogeographical domains of {C}ameroon and reared to adults in insectaries. {S}tandard {WHO} insecticide susceptibility tests were carried out with 4% {DDT}, 0.75% permethrin and 0.05% deltamethrin. {M}ortality rates and knockdown times (kdt(50) and kdt(95)) were determined and the effect of pre-exposure to the synergists {DEF}, {DEM} and {PBO} was assessed. {T}ested mosquitoes were identified to species and molecular forms ({M} or {S}) using {PCR}-{RFLP}. {T}he hot ligation method was used to depict kdr mutations and biochemical assays were conducted to assess detoxifying enzyme activities. {R}esults: {T}he {A}n. arabiensis population from {P}itoa was fully susceptible to {DDT} and permethrin (mortality rates > 98%) and showed reduced susceptibility to deltamethrin. {R}esistance to {DDT} was widespread in {A}n. gambiae s.s. populations and heterogeneous levels of susceptibility to permethrin and deltamethrin were observed. {I}n many cases, prior exposure to synergists partially restored insecticide knockdown effect and increased mortality rates, suggesting a role of detoxifying enzymes in increasing mosquito survival upon challenge by pyrethroids and, to a lower extent {DDT}. {T}he distribution of kdr alleles suggested a major role of kdr-based resistance in the {S} form of {A}n. gambiae. {I}n biochemical tests, all but one mosquito population overexpressed {P}450 activity, whereas baseline {GST} activity was low and similar in all field mosquito populations and in the control. {C}onclusion: {I}n {C}ameroon, multiple resistance mechanisms segregate in the {S} form of {A}n. gambiae resulting in heterogeneous resistance profiles, whereas in the {M} form and {A}n. arabiensis insecticide tolerance seems to be essentially mediated by enzyme-based detoxification. {S}ynergists partially restored susceptibility to pyrethroid insecticides, and might help mitigate the impact of vector resistance in the field. {H}owever, additional vector control tools are needed to further impact on malaria transmission in such settings.},
  keywords = {{CAMEROUN}},
  booktitle = {},
  journal = {{P}arasites and {V}ectors},
  volume = {6},
  numero = {},
  pages = {41},
  ISSN = {1756-3305},
  year = {2013},
  DOI = {10.1186/1756-3305-6-41},
  URL = {https://www.documentation.ird.fr/hor/fdi:010060708},
}