Diversity and antibiotic resistance profiles of bacteria isolated from the oral cavity of captive snakes

Posted by
  Diversity and antibiotic resistance profiles of bacteria isolated from the oral cavity of captive snakes Abstract Venomous snake bites are a global public health issue, causing between 81 000 and 138 000 annual deaths and 400 000 permanent disabilities. This study investigated the oral bacterial diversity and antibiotic resistance profiles in captive  Viperidae  snakes. Oral swabs from 48 specimens across four species ( Porthidium lansbergii ,  Bothriechis nigroviridis ,  Cerrophidion sasai , and  Bothrops asper ) were analyzed using culture-dependent methods. Bacterial isolation and identification using the VITEK 2 automated system revealed 41 strains from 12 genera, predominantly Gram-negative bacteria, including  Morganella morganii  (11 isolates) and  Providencia rettgeri  (10 isolates). Antibiotic susceptibility testing demonstrated significant resistance patterns, with 100% resistance to cephalothin and cefazolin i...

Molecular phylogeny of the wolf spider subfamily Allocosinae in South America (Araneae: Lycosidae)

Posted by

 


Molecular phylogeny of the wolf spider subfamily Allocosinae in South America (Araneae: Lycosidae)

Abstract

The wolf spiders of the subfamily Allocosinae are known for their complex taxonomy, especially in the Neotropical region. Despite previous taxonomic and phylogenetic studies, the diversity and phylogenetic relationships of the subfamily remain largely unknown. This study aims to clarify the evolutionary relationships within South American Allocosinae, hypothesizing a greater diversity than currently recognized and seeking to resolve ambiguities in genus-level classification. We used a combination of mitochondrial and nuclear gene sequences to construct phylogenetic analyses for 73 specimens across 13 species of Allocosinae. Analyses using both maximum likelihood and Bayesian frameworks were conducted to examine internal relationships and phylogenetic structure and to infer a timeline of diversification. Additionally, species delimitation was conducted to identify cryptic lineages. Our results recover the specimens considered to be representatives of the subfamily Allocosinae as a monophyletic group, and identified five major clades. Divergence time estimates suggested Allocosinae originated in the Early Miocene (15–22 million years ago), and underwent significant diversification during the Pleistocene. Species delimitation analysis based on single markers uncovered 24 lineages, indicating potentially overlooked species. Allocosinae has shown to be an interesting group to study incipient speciation processes, ecology of coastal environments and atypical behaviors such as sex role reversal. Knowing and understanding the evolutionary history and relationships within the subfamily is necessary for progress in its study in any field of biology.

Laborda Á, Simó M, Piacentini LN, Brescovit AD, Beloso C, Aisenberg A, Arnedo MA, Ramírez MJ, Bidegaray-Batista L (2025) Molecular phylogeny of the wolf spider subfamily Allocosinae in South America (Araneae: Lycosidae). Arthropod Systematics & Phylogeny 83: 353-367. https://doi.org/10.3897/asp.83.e152943