University of Antananarivo

About: University of Antananarivo is a education organization based out in Antananarivo, Madagascar. It is known for research contribution in the topics: Population & Lemur. The organization has 1561 authors who have published 1703 publications receiving 30922 citations. The organization is also known as: Tananarive University & Antananarivo University.

Diversity, external morphology and 'reverse taxonomy' in the specialized tadpoles of Malagasy river bank frogs of the subgenus Ochthomantis (genus Mantidactylus)

Abstract: We provide detailed morphological descriptions of the tadpoles of Malagasy river bank frogs of the subgenera Ochthomantis and Maitsomantis (genus Mantidactylus, family Mantellidae), and data on relative abundance and habitat preferences of Ochthomantis species from Ranomafana National Park in southeastern Madagascar. Our study includes the tadpoles of six described and four undescribed candidate species. Eight of these larvae were previously unknown. Tadpoles were identified by DNA barcoding. Due to the very rudimentary taxonomic knowledge on Ochthomantis, we followed a ‘reverse taxonomy’ approach in which adult classification was to a great part deter mined on the basis of larval differences. By this procedure we even identified one candidate species whose adults remain still unknown. The majority of tadpoles in Ochthomantis and Maitsomantis have a rather similar body shape and they usually have similar habitat requirements. However, on the basis of the structure of their oral disk we identified three distinct groups: the first includes the femoralis-like tadpoles of Mantidactylus femoralis, M. ambreensis, M. zolitschka, M. argenteus, and of the candidate species named M. sp. 42, M. sp. 43 and M. sp. 47. They all have a reduced oral disk with poorly keratinized jaw sheaths and labial teeth. The mocquardi-like tadpoles of M. mocquardi and M. sp. 64 are placed in the second group and are characterized by a further reduction of oral disk structures, i.e. a complete lack of labial teeth. The third group includes only M. majori and is characterized by the transformation of the upper jaw sheath into three thorn-shaped projections. Based on a preliminary molecular phylogenetic analysis the reduction of keratinized oral structures in M. majori may have occurred convergently to that in M. mocquardi. The ecological data indicate that the tadpoles of the three most abundant species in Ranomafana (M. femoralis, M. majori and M. sp. 47) do not obviously differ in their choice of microhabitat although the differences in their oral structures indicate that they might use different food resources. They all show a preference for the stream areas with slow current and leaf litter substrate.

The double odyssey of Madagascan polystome flatworms leads to new insights on the origins of their amphibian hosts.

Abstract: Polystomatid flatworms are parasites of high host specificity, which mainly infect amphibian hosts. Only one polystome species has so far been recorded from Madagascar despite the high species richness and endemicity of amphibians on this island. Out of the 86 screened Malagasy frog species, we recovered polystomes from 25 in the families Ptychadenidae and Mantellidae. Molecular phylogenetic analysis uncovered an unexpected diversity of polystome species belonging to two separate clades: one forming a lineage within the genus Metapolystoma , with one species in Ptychadena and several species in the mantellid host genera Aglyptodactylus and Boophis ; and the second corresponding to an undescribed genus that was found in the species of the subfamily Mantellinae in the family Mantellidae. The phylogenetic position of the undescribed genus along with molecular dating suggests that it may have colonized Madagascar in the Late Mesozoic or Early Cainozoic. By contrast, the more recent origin of Metapolystoma in Madagascar at ca 14–2 Myr ago strongly suggests that the ancestors of Ptychadena mascareniensis colonized Madagascar naturally by overseas dispersal, carrying their Metapolystoma parasites. Our findings provide a striking example of how parasite data can supply novel insights into the biogeographic history of their hosts.

A Multicountry Molecular Analysis of Salmonella enterica Serovar Typhi With Reduced Susceptibility to Ciprofloxacin in Sub-Saharan Africa

Abstract: BACKGROUND Salmonella enterica serovar Typhi is a predominant cause of bloodstream infections in sub-Saharan Africa (SSA). Increasing numbers of S. Typhi with resistance to ciprofloxacin have been reported from different parts of the world. However, data from SSA are limited. In this study, we aimed to measure the ciprofloxacin susceptibility of S. Typhi isolated from patients with febrile illness in SSA. METHODS Febrile patients from 9 sites within 6 countries in SSA with a body temperature of ≥38.0°C were enrolled in this study. Blood samples were obtained for bacterial culture, and Salmonella isolates were identified biochemically and confirmed by multiplex polymerase chain reaction (PCR). Antimicrobial susceptibility of all Salmonella isolates was performed by disk diffusion test, and minimum inhibitory concentrations (MICs) against ciprofloxacin were measured by Etest. All Salmonella isolates with reduced susceptibility to ciprofloxacin (MIC > 0.06 µg/mL) were screened for mutations in quinolone resistance-determining regions in target genes, and the presence of plasmid-mediated quinolone resistance (PMQR) genes was assessed by PCR. RESULTS A total of 8161 blood cultures were performed, and 100 (1.2%) S. Typhi, 2 (<0.1%) Salmonella enterica serovar Paratyphi A, and 27 (0.3%) nontyphoid Salmonella (NTS) were isolated. Multidrug-resistant S. Typhi were isolated in Kenya (79% [n = 38]) and Tanzania (89% [n = 8]) only. Reduced ciprofloxacin-susceptible (22% [n = 11]) S. Typhi were isolated only in Kenya. Among those 11 isolates, all had a Glu133Gly mutation in the gyrA gene combined with either a gyrA (Ser83Phe) or gyrB mutation (Ser464Phe). One Salmonella Paratyphi A isolate with reduced susceptibility to ciprofloxacin was found in Senegal, with 1 mutation in gyrA (Ser83Phe) and a second mutation in parC (Ser57Phe). Mutations in the parE gene and PMQR genes were not detected in any isolate. CONCLUSIONS Salmonella Typhi with reduced susceptibility to ciprofloxacin was not distributed homogenously throughout SSA. Its prevalence was very high in Kenya, and was not observed in other study countries. Continuous monitoring of antimicrobial susceptibility is required to follow the potential spread of antimicrobial-resistant isolates throughout SSA.