Background: Mosquito vectors cause a significant human public health burden through the transmission of pathogens. Due to the expansion of international travel and trade, the dispersal of these mosquito vectors and the pathogens they carry is on the rise. Entomological surveillance is therefore required which relies on accurate mosquito species identification. This study aimed to optimize the use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for mosquito identification. Methods: Aedes aegypti of the Bora-Bora strain and 11 field-sampled mosquito species were used in this study. Analyses were performed to study the impact of the trapping duration on mosquito identification with MALDI-TOF MS. The best preservation methods to use for short, medium and long-term preservation before MALDI-TOF MS analysis were also assessed. In addition, the number of specimens per species required for MALDI-TOF MS database creation was determined. The first MALDI-TOF database of New Caledonian mosquitoes was assembled and the optimal threshold for mosquito species identification according to the sensitivity and specificity of this technique was determined. Results: This study showed that the identification scores decreased as the trapping duration increased. High identification scores were obtained for mosquitoes preserved on silica gel and cotton at room temperature and those frozen at − 20 °C, even after two months of preservation. In addition, the results showed that the scores increased according to the number of main spectrum patterns (MSPs) used until they reached a plateau at 5 MSPs for Ae. aegypti. Mosquitoes (n = 67) belonging to 11 species were used to create the MALDI-TOF reference database. During blind test analysis, 96% of mosquitoes tested (n = 224) were correctly identified. Finally, based on MALDI-TOF MS sensitivity and specificity, the threshold value of 1.8 was retained for a secure identification score. Conclusions: MALDI-TOF MS allows accurate species identification with high sensitivity and specificity and is a promising tool in public health for mosquito vector surveillance.

Background Hemotropic mycoplasmas, previously classified in the genus Eperythrozoon, have been reported as causing human infections in Brazil, China, Japan and Spain. Methods In 2017, we detected DNA from “Candidatus Mycoplasma haemohominis” in the blood of a Melanesian patient from New Caledonia presenting with febrile splenomegaly,weight loss, life-threatening autoimmune haemolytic anemia and hemophagocytosis. The full genome of the bacterium was sequenced from a blood isolate. Subsequently, we tested retrospectively (2011-2017) and prospectively (2018-2019) patients who had been hospitalized with a similar clinico-biological picture. In addition, as these patients had been in contact with frugivorous bats (authorized under conditions for hunting and eating in New Caledonia) we investigated the role of these animals and their biting flies by testing them for hemotropic mycoplasmas. Results Fifteen patients were found to be infected by this hemotropic mycoplasma. Among them, four (27%) died following splenectomy performed for spontaneous spleen rupture, or to cure refractory autoimmune haemolytic anemia. The bacterium was cultivated from the patient's blood. The full genome of the Neocaledonian “Candidatus M. haemohominis” strain differed from that of a recently identified Japanese strain. Forty-six percent of 40 tested Pteropus bats and 100% of collected bat flies Cyclopodia horsfieldi (Nycteribiidae, Diptera) were positive. Human,bat and dipteran strains were highly similar. Conclusions The bacterium being widely distributed in bats, “Candidatus M. haemohominis” should be regarded as a potential cause of severe infections in humans.

S. Tubiana). y Bruno Hoen and Xavier Duval contributed equally. z The members of COMBAT study group are listed at the Acknowledgments section. Contents lists available at ScienceDirect Clinical Microbiology and Infectionj o u r n a l h o m e p a g e : w w w . c l i n i c a l m i c r o b i o l o g y a n d i n f e c t i o n . c o m

NSTIs are particularly frequent in New Caledonia. Local health care workers should have a high index of suspicion for the disease to initiate surgical and medical treatments early.