ABSTRACT
Viviparity is reported for Gegeneophis seshachari (Gymnophiona: Caeciliidae) from a gravid female containing four oviductal foetuses. The oviducts are highly vascularized and contain patches of thickened, layered tissue similar to foetal gut contents. Gegeneophis seshachari probably resemble other viviparous caecilians in having foetuses that ingest thickened oviduct lining using specialized deciduous teeth. This is the first report of viviparity in Asian amphibians and Indo-Seychellean caeciliids. Gegeneophis is the only caecilian genus known to include oviparous and viviparous species, and G. seshachari is the smallest known viviparous caecilian. Phylogenetic analysis of mitochondrial DNA sequences supports assignment of G. seshachari to a monophyletic Gegeneophis. Character optimization indicates that viviparity has evolved independently at least four times within Gymnophiona--a rate of incidence relative to the number of extant species that is higher than for other vertebrate groups except squamate reptiles. Our findings strengthen the proposal that caecilian reproduction demands further attention.
Subject(s)
Amphibians/physiology , Biological Evolution , Viviparity, Nonmammalian , Amphibians/anatomy & histology , Animals , Bayes Theorem , DNA, Mitochondrial/genetics , Female , Likelihood Functions , Models, Genetic , Phylogeny , Sequence Alignment , Sequence Analysis, DNAABSTRACT
Flesh flies (Diptera: Sarcophagidae) are well known cause of myiasis and their gut bacteria have never been studied for antimicrobial activity against bacteria. Antimicrobial studies of Myroides spp. are restricted to nosocomial strains. A Gram-negative bacterium, Myroides sp., was isolated from the gut of adult flesh flies (Sarcophaga sp.) and submitted to evaluation of nutritional parameters using Biolog GN, 16S rRNA gene sequencing, susceptibility to various antimicrobials by disc diffusion method and detection of metallo â-lactamase genes (TUS/MUS). The antagonistic effects were tested on Gram-negative and Gram-positive bacteria isolated from human clinical specimens, environmental samples and insect mid gut. Bacterial species included were Aeromonas hydrophila, A. culicicola, Morganella morganii subsp. sibonii, Ochrobactrum anthropi, Weissella confusa, Escherichia coli, Ochrobactrum sp., Serratia sp., Kestersia sp., Ignatzschineria sp., Bacillus sp. The Myroides sp. strain was resistant to penicillin-G, erythromycin, streptomycin, amikacin, kanamycin, gentamycin, ampicillin, trimethoprim and tobramycin. These strain showed antibacterial action against all bacterial strains except W. confusa, Ignatzschineria sp., A. hydrophila and M. morganii subsp. sibonii. The multidrug resistance of the strain was similar to the resistance of clinical isolates, inhibiting growth of bacteria from clinical, environmental and insect gut samples. The metallo â-lactamase (TUS/MUS) genes were absent, and resistance due to these genes was ruled out, indicating involvement of other secretion machinery.
Moscas varejeiras (Diptera: Sarcophagidae) são causa conhecida de miíase e as bactérias de seus intestinos nunca foram estudadas quanto à atividade antibacteriana. Estudos antimicrobianos de Myroides spp restringem-se à cepas hospitalares. Uma bactéria Gram negativa, Myroides sp, foi isolada do intestino de moscas varejeiras adultas (Sarcophaga sp) e submetida à avaliação de parâmetros nutricionais pelo sistema BIOLOG GN, ao sequenciamento genético 16S rRNA, à sensibilidade a vários antimicrobianos pelo método de difusão de discos e à detecção dos genes de metalo beta lactamases (TUS/MUS). Os efeitos antagonistas foram testados contra bactérias Gram negativas e Gram positivas isoladas de material clínico humano, amostras ambientais e intestino do inseto. As espécies bacterianas incluíram Aeromonas hydrophila, A. culicicola, Morganella morganii subsp sibonii, Ochrobactrum anthropi, Weissella confusa, Escherichia coli, Ochrobactrum sp, Serratia sp, Kestersia sp, Ignatzschineria sp e Bacillus sp. A cepa Myroides sp foi resistente à penicilina G, eritromicina, estreptomicina, amicacina, canamicina, gentamicina, ampicilina, trimetoprim e tobramicina. Esta cepa apresentou atividade antimicrobiana contra todas as cepas exceto W.confusa, Ignatzschineria sp, A. hydrophila e M. morgani subsp sibonii. A resistência múltipla da cepa foi semelhante à de isolados clínicos, inibindo bactérias das amostras clínicas, ambientais e do intestino do inseto. Os genes de metalo beta lactamases (TUS/MUS) estavam ausentes, excluindo-se a resistência mediada por esses genes, o que indica o envolvimento de um mecanismo alternativo de secreção.
Subject(s)
Animals , Gram-Negative Bacteria/genetics , Gram-Negative Bacteria/isolation & purification , Diptera , Drug Resistance, Microbial , In Vitro Techniques , beta-Lactamases/analysis , Diffusion , MethodsABSTRACT
FLESH FLIES (DIPTERA: Sarcophagidae) are well known cause of myiasis and their gut bacteria have never been studied for antimicrobial activity against bacteria. Antimicrobial studies of Myroides spp. are restricted to nosocomial strains. A Gram-negative bacterium, Myroides sp., was isolated from the gut of adult flesh flies (Sarcophaga sp.) and submitted to evaluation of nutritional parameters using Biolog GN, 16S rRNA gene sequencing, susceptibility to various antimicrobials by disc diffusion method and detection of metallo ß-lactamase genes (TUS/MUS). The antagonistic effects were tested on Gram-negative and Gram-positive bacteria isolated from human clinical specimens, environmental samples and insect mid gut. Bacterial species included were Aeromonas hydrophila, A. culicicola, Morganella morganii subsp. sibonii, Ochrobactrum anthropi, Weissella confusa, Escherichia coli, Ochrobactrum sp., Serratia sp., Kestersia sp., Ignatzschineria sp., Bacillus sp. The Myroides sp. strain was resistant to penicillin-G, erythromycin, streptomycin, amikacin, kanamycin, gentamycin, ampicillin, trimethoprim and tobramycin. These strain showed antibacterial action against all bacterial strains except W. confusa, Ignatzschineria sp., A. hydrophila and M. morganii subsp. sibonii. The multidrug resistance of the strain was similar to the resistance of clinical isolates, inhibiting growth of bacteria from clinical, environmental and insect gut samples. The metallo ß-lactamase (TUS/MUS) genes were absent, and resistance due to these genes was ruled out, indicating involvement of other secretion machinery.
