title: Enzymatic activities and effects of mycovirus infection on the virulence of Metarhizium anisopliae in Rhipicephalus microplus.
abstract: The present study aimed to evaluate the pathogenic potential of different Metarhizium anisopliae s.l. isolates and to determine whether differences in enzymatic activities of proteases, lipases and chitinases and infection with mycoviruses affect the control of Rhipicephalus microplus achieved by these fungal isolates. Engorged female ticks were exposed to fungal suspensions. The lipolytic and proteolytic activities in the isolates were evaluated using chromogenic substrates and the chitinolytic activity was determined using fluorescent substrates. A gel zymography was performed to determine the approximate size of serine proteases released by M. anisopliae isolates. To detect mycoviral infections, dsRNA was digested using both RNAse A and S1 endonuclease; samples were analyzed on an agarose gel. Four of the five isolates tested were infected with mycovirus; however, the level of control of R. microplus ticks achieved with the only isolate free of infection (isolate CG 347) was low. This finding suggests that mycoviral infection does not affect the virulence of fungi against ticks. Although all five isolates were considered pathogenic to R. microplus, the best tick control and the highest levels of enzymatic activity were achieved with the isolates CG 629 and CG 148. The in vitro activities of lipases, proteases and chitinases produced by M. anisopliae s.l. differed among isolates and may be related to their virulence.
authors.affiliation: Universidade Federal Rural do Rio de Janeiro, Instituto de Veterinária, Departamento de Parasitologia Animal, Seropédica, RJ, Brazil.
authors.forename: Wendell M S
authors.initials: WM
authors.lastname: Perinotto
authors.affiliation: Universidade Federal Rural do Rio de Janeiro, Instituto de Veterinária, Departamento de Parasitologia Animal, Seropédica, RJ, Brazil.
authors.forename: Patricia S
authors.initials: PS
authors.lastname: Golo
authors.affiliation: Universidade Federal Rural do Rio de Janeiro, Instituto de Veterinária, Departamento de Parasitologia Animal, Seropédica, RJ, Brazil.
authors.forename: Caio J B
authors.initials: CJ
authors.lastname: Coutinho Rodrigues
authors.affiliation: Universidade Federal Rural do Rio de Janeiro, Instituto de Veterinária, Departamento de Parasitologia Animal, Seropédica, RJ, Brazil.
authors.forename: Fillipe A
authors.initials: FA
authors.lastname: Sá
authors.affiliation: The Scripps Research Institute, Department of Chemical Physiology, La Jolla, United States.
authors.forename: Lucélia
authors.initials: L
authors.lastname: Santi
authors.affiliation: The Scripps Research Institute, Department of Chemical Physiology, La Jolla, United States.
authors.forename: Walter O
authors.initials: WO
authors.lastname: Beys da Silva
authors.affiliation: Universidade Federal do Rio Grande do Sul, Departamento de Biotecnologia, Porto Alegre, RS, Brazil.
authors.forename: Angela
authors.initials: A
authors.lastname: Junges
authors.affiliation: Universidade Federal do Rio Grande do Sul, Departamento de Biotecnologia, Porto Alegre, RS, Brazil.
authors.forename: Marilene H
authors.initials: MH
authors.lastname: Vainstein
authors.affiliation: Universidade Federal do Rio Grande do Sul, Departamento de Biotecnologia, Porto Alegre, RS, Brazil.
authors.forename: Augusto
authors.initials: A
authors.lastname: Schrank
authors.affiliation: Universidade Federal Rural do Rio de Janeiro, Instituto de Química, Departamento de Bioquímica, Seropédica, RJ, Brazil.
authors.forename: Cristiane M C
authors.initials: CM
authors.lastname: Salles
authors.affiliation: Universidade Federal Rural do Rio de Janeiro, Instituto de Veterinária, Departamento de Parasitologia Animal, Seropédica, RJ, Brazil. Electronic address: vaniabit@ufrrj.br.
authors.forename: Vânia R E P
authors.initials: VR
authors.lastname: Bittencourt
mesh_terms: D000818:Animals; D002688:Chitinases / Q000378:metabolism; D005260:Female; D008049:Lipase / Q000378:metabolism; D052981:Metarhizium / Q000201:enzymology / Q000472:pathogenicity / Q000821:virology; D010447:Peptide Hydrolases / Q000378:metabolism; D048494:Rhipicephalus / Q000382:microbiology*; D013983:Tick Control; D018406:Virus Physiological Phenomena
chemical_list: D008049:Lipase; D002688:Chitinases; D010447:Peptide Hydrolases
keywords: Biological control; Chitinases; Lipases; Mycovirus; Proteases