Antifungal activity of Stenotrophomonas maltophilia in Stomoxys calcitranslarvae

Abstract

The microbiota present in Stomoxys calcitrans larvae may assist their survival in contaminated environments through production of inhibitory substances. Bacteriological identification methods, the polymerase chain reaction (PCR) and scanning electron microscopy (SEM) were used to detect a bacterium naturally present in mucus and macerated S. calcitrans larvae. The antifungal activity was determined based on the results from disk diffusion tests on an artificial solid medium. The bacterium was identified as Stenotrophomonas maltophilia and presented antifungal activity against Beauveria bassiana sensu lato isolates CG 138, CG 228 and ESALQ 986. This result suggests that the larval microbiota is a factor that can compromise the use of B. bassiana s.l. fungus for biological control of S. calcitrans larvae.Keywords: Stenotrophomonas maltophilia, Stomoxys calcitrans, antifungal activity. ResumoA microbiota presente em larvas de Stomoxys calcitrans pode auxiliar na sua sobrevivência em ambientes contaminados, devido à produção de substâncias inibidoras. Métodos bacteriológicos de identificação, reação em cadeia da polimerase (PCR) e microscopia eletrônica de varredura (MEV) foram utilizados para detectar uma bactéria naturalmente presente no muco e macerado de larvas de S. calcitrans. A atividade antifúngica foi baseada nos resultados obtidos no teste de difusão em meio sólido artificial. A bactéria foi identificada como Stenotrophomonas maltophilia e apresentou atividade antifúngica contra os isolados CG 138, CG 228 e ESALQ 986 de Beauveria bassiana sensu lato. Estes resultados sugerem que a microbiota larval é um fator que pode comprometer o uso de B. bassiana s.l. no controle biológico de larvas de S. calcitrans.

Bacterial Community Diversity Harboured by Interacting Species

“…bipustulata laboratory samples. A bacterium of the genus Stenotrophomonas has been recently described to protect its host, the fly Stomoxys calcitrans , against Beauveria bassiana an entomopathogenic fungus [ 92 ]. These bacteria are described as environmental bacteria present in water and soils but they are also described as opportunistic gut bacteria that can invade insect guts and prevent the invasion by other pathogenic bacteria [ 8 ].…”

Infection of the Stable Fly, Stomoxys calcitrans, L. 1758 (Diptera: Muscidae) by the Entomopathogenic Fungi Metarhizium anisopliae (Hypocreales: Clavicipitaceae) Negatively Affects Its Survival, Feeding Propensity, Fecundity, Fertility, and Fitness Parameters

“…About 90% of the larvae contaminated with the 11 strains of M. anisopliae (Figure 6Ai) and those contaminated with high concentrations of ICIPE 30 (Figure 6Aii) reached the pupal stage. Moraes et al (2014) demonstrated the existence of antifungal activity of S. calcitrans larvae against entomopathogenic fungal infection. The authors found that macerated solution of S. calcitrans larvae reduces the growth of B. bassiana; suggesting that these larvae produce robust anti-fungal substances protecting them from infection.…”

“…The authors found that macerated solution of S. calcitrans larvae reduces the growth of B. bassiana; suggesting that these larvae produce robust anti-fungal substances protecting them from infection. When subjected to high-performance liquid chromatography (HPLC) analysis, new peaks in the chromatogram that could represent the antifungal molecules were obtained from the solution of macerated B. bassiana infected larvae as compared to the control group (Moraes et al, 2014). Earlier, a peptide affecting microorganism growth (stomoxyn) was identified in the exterior midgut of S. calcitrans (Boulanger et al, 2002).…”

Immune Response and Hemolymph Microbiota ofApis melliferaandApis ceranaAfter the Challenge With RecombinantVarroaToxic Protein

“…However, this species resides in a broad range of environments and are commonly identi ed only as multidrug-resistant opportunistic pathogens of humans [47], in soils or in association with plants [48], and also associated with multiple insect species, including the diamondback moth Plutella xylostella [49], the red turpentine beetle Dendroctonus valens [50], the twelve-toothed pine bark beetle Ips sexdentatus [51], the asian malaria mosquito Anopheles stephensi [52], the peach fruit y Bactrocera zonata [53], the muga silkworm Antheraea assamensis [54] and the wings of the Colorado potato beetle Leptinotarsa decemlineata [55]. S. maltophilia was also isolated from the honeydew of Indian lac insect Kerria lacca [56] and from the stable y Stomoxys calcitrans larvae presenting antifungal activity against Beauveria bassiana [57]. Furthermore, S. maltophilia associated with Delia antiqua larvae can inhibit B. bassiana infection [58].…”