Antibiotic-resistant bacteria inhibited by extracts and fractions from Brazilian marine sponges

Abstract

RESUMO: "Bactérias resistentes a antibióticos inibidas por extratos e frações de esponjas marinhas do Brasil". O número crescente de bactérias resistentes aos antibióticos tem se tornado um sério problema médico nos últimos anos. As esponjas marinhas são uma fonte rica em compostos bioativos e muitas espécies podem ser úteis para o desenvolvimento de novos antimicrobianos. Esse estudo descreve uma triagem in vitro de esponjas para a pesquisa de novas substâncias contra bactérias resistentes. Os extratos de esponjas foram testados sobre 44 estirpes bacterianas, incluindo quatorze resistentes a antibióticos. Dez entre doze espécies de esponjas apresentaram atividade em um ou mais bioensaios. Os extratos aquosos de Cinachyrella sp. e Petromica citrina apresentaram um amplo espectro de ação sobre estirpes bacterianas resistentes, tais como, Staphylococcus aureus, Staphylococcus coagulase-negativos e Enterococcus faecalis. O extrato aquoso de P. citrina foi fracionado e a fração aquosa apresentou atividade inibitória sobre estirpes de Staphylococcus. Esta fração, na concentração do CMI (16 μg/mL), demonstrou efeito bactericida sobre células de S. aureus na fase exponencial de crescimento. O mecanismo de ação da fração ainda não foi elucidado, mas nós observamos que esta afeta a síntese protéica de Staphylococcus. Nossos resultados demonstraram pela primeira vez que Petromica citrina é uma fonte potencial de novas drogas para o tratamento de infecções causadas por bactérias resistentes. Unitermos: atividade antibacteriana, bactéria resistente a antibióticos, esponjas marinhas, Petromica citrina. ABSTRACT:The growing number of bacterial strains resistant to conventional antibiotics has become a serious medical problem in recent years. Marine sponges are a rich source of bioactive compounds, and many species can be useful for the development of new antimicrobial drugs. This study reports the in vitro screening of marine sponges in the search for novel substances against antibiotic-resistant bacteria. Sponge extracts were tested against 44 bacterial strains, including fourteen antibiotic-resistant strains. Ten out of the twelve sponge species studied showed activity in one or more of the bioassays. Aqueous extracts of Cinachyrella sp. and Petromica citrina showed a large action spectrum over resistant-bacteria such as Staphylococcus aureus, coagulase-negative staphylococci and Enterococcus faecalis. Aqueous extract of P. citrina was fractioned and aqueous fraction showed a greatest inhibitory activity on Staphylococcus strains. In addition, this fraction demonstrated a bactericidal effect on exponentially growing S. aureus cells at the MIC (16 µg/ mL). The mechanism of action of bioactive fraction is still unclear, but we showed that it affect protein biosynthesis of Staphylococcus. Our results demonstrated for the first time that P. citrina is a potential source of new drugs for the treatment of infections by antibiotic-resistant bacteria.

Macrofauna inhabiting the spongeParaleucilla magna(Porifera: Calcarea) in Rio de Janeiro, Brazil

“…A possible explanation for this difference in macrofauna abundance is the presence of chemicals that might reduce predation in M. microsigmatosa and, consequently, provide more protection for its associated macrofauna. Although this hypothesis has not been tested, M. microsigmatosa does produce a series of compounds, some of which inhibit microorganism proliferation (Compagnone et al, 1999;Marinho et al, 2009Marinho et al, , 2010Santos et al, 2010). The potential importance of sponge allelochemicals in influencing the composition and abundance of associated fauna has already been pointed out (Koukouras et al, 1992;Skilleter et al, 2005).…”

Antiviral Activity of Bacillus sp. Isolated from the Marine Sponge Petromica citrina against Bovine Viral Diarrhea Virus, a Surrogate Model of the Hepatitis C Virus

“…The marine sponge Petromica citrina is endemic in the country. Previously, antimicrobial activity against some resistant bacteria from aqueous extracts of this sponge has been demonstrated [26]. However, here, we only isolated active extracts of microorganisms from this sponge.…”

Investigation of biotechnological potential of sponge‐associated bacteria collected in B razilian coast

“…Plates were incubated at 37°C for 18 h, and inhibition zones ≥10 mm were considered indicative of inhibitory activity (Marinho et al . ).…”

“…Fractions (20 ll) were spotted on BHI agar and 10 5 cells of indicator strains in 3 ml of BHI soft agar were poured over the plates. Plates were incubated at 37°C for 18 h, and inhibition zones ≥10 mm were considered indicative of inhibitory activity (Marinho et al 2010).…”