Biofilm analyses and exoproduct release by clinical and environmental isolates of Burkholderia pseudomallei from Brazil

Objective:To characterize biofilm production by clinical(n=21)and environmental(n=11)isolates of Burkholderia pseudomallei and evaluate the production of proteases,hemolysins and siderophores.Methods:Initially,the 32 strains were evaluated for biofilm production in Müller-Hinton broth-1%glucose(MH-1%glucose)and BHI broth-1%glucose,using the crystal violet staining technique.Subsequently,growing(48 h)and mature(72 h)biofilms were evaluated by confocal microscopy.Finally,the production of proteases,hemolysins and siderophores by planktonic aggregates,growing biofilms and mature biofilms was evaluated.Results:All isolates produced biofilms,but clinical isolates had significantly higher biomass in both MH-1%glucose(P<0.001)and BHI-glucose 1%(P=0.005).The structural analyses by confocal microscopy showed thick biofilms,composed of multiple layers of cells,homogeneously arranged,with mature biofilms of clinical isolates presenting higher biomass(P=0.019)and thickness of the entire area(P=0.029),and lower roughness coefficient(P=0.007)than those of environmental isolates.Protease production by growing biofilms was significantly greater than that of planktonic(P<0.001)and mature biofilms(P<0.001).Hemolysin release by planktonic aggregates was higher than that of biofilms(P<0.001).Regarding siderophores,mature biofilms presented higher production than growing biofilms(P<0.001)and planktonic aggregates(P<0.001).Conclusions:Clinical isolates have higher production of biofilms than their environmental counterparts;protease and siderophores seem important for growth and maintenance of Burkholderia pseu­domallei biofilms.

Research advances on the multiple uses of Moringa oleifera: a sustainable alternative for socially neglected population

Moringa oleifera Lam(Moringaceae) is a plant with high nutritional and medicinal value. Native to India, it is now widely distributed throughout tropical and subtropical regions of the world. Its different parts are sources of proteins, vitamins and minerals and present different pharmacological and biotechnological potential. Moreover, M. oleifera seeds are widely used in water and effluent treatment, for their coagulation, flocculation and sedimentation properties, their ability of improving water quality, by reducing organic matter and microbial load, with special applicability in intensive animal production systems, such as aquaculture. In addition, due to its high nutritional value and several medicinal properties, this tree may act as a nutritional and medical alternative for socially neglected populations. In this context, this review gathers information on M. oleifera, emphasizing its chemical constituents, nutritional, pharmacological and antimicrobial properties, applications in the treatment of water effluents, and ecological and social aspects.

Vibrio spp.from Macrobrachium amazonicum prawn farming are inhibited by Moringa oleifera extracts

Objective:To investigate the in vitro antimicrobial potential of extracts of stem,leaves,flowers,pods and seeds of Moringu okifera(M.okifera) against Vibrio spp.from hatchery water and the prawn Mmrobrachium amazonicum.Methods:The ethanol extracts of stem,leaves,pods and seeds and chloroform extract of flowers of M.oleifera were tested against Vibrio cholerue(V.cholerae) serogroups non-O1/non-O139(n=4).Vibrio vulnificus(n=l) and Vibrio mimicus(n=1).Escherichia coli(E.coli)(ATCC(?) 25922) was used as quality control.Vibrio species were obtained from Macmbrachium amazonicum prawns and from hatchery water from prawn farming.The Minimum Inhibitory Concentration(MIC) was determined by broth microdilution method.Results:The best result was obtained with the ethanol extract of pods,which inhibited three strains of the V.choleme,Vibrio vulnificus,Vibrio minimis and E.coli(MIC range 0.312-5.000 mg/mL).The chloroform extract of flowers was effective against all V.chokrae strains and E.coli(MIC range 0.625-1.250 mg/mL).However,the ethanol extracts of stem and seeds showed low effectiveness in inhibiting the bacterial growth.Conclusions:The extracts of pods,flowers and leaves of M.oleifera have potential for the control of Vibrio spp.Further studies are necessary to isolate the bioaetive compounds responsible for this antimicrobial activity.

Enterobacteria and Vibrio from Macrobrachium amazonicum prawn farming in Fortaleza,Ceará,Brazil

Objective:To investigate the isolation of enterobacteria associated with Macrobrachium amazonicum(M.amazonicum) farming and evaluate the in vitro antimicrobial susceptibility of Vibrio strains.Methods:Strains were isolated from female M.amazonicum prawns and environmental and hatchery water.Biochemical assays were used to identify bacterial genera and those belonging to the genus Vibrio were submitted to further analyses for species identification,through Vitek 2 automated system and scrotyping.Susceptibility test was performed according to Clinical Laboratory Standards Institute.Results:The following genera of enlerobacteria were recovered:Enterobacter(n=11),Citrobacter(n=10),Proteus(n=2),Serratia(n=2),Kluyvera(n=2),Providencia(n=2),Cedecea(n=1),Escherichia(n=1).Edwardsiella(n=1) and BulliauxeUa(n=1).As for Vibrio,three species were identified:Vibrio cholerae non-O1/non-O139(n=4).Vibrio vulnificus(V.vulnificus)(n=1) and Vibrio mimicus(n=1).Vibrio spp.showed minimum inhibitory concentrations values within the susceptibility range established by Clinical Laboratory Standards Institute for almost all antibiotics,except for V.vulnificus,which presented intermediate profile to ampicillin.Conclusions:Enterobacteria do not seem to be the most important pathogens associated with M.amazonicum farming,whereas the recovery of Vibrio spp.from larviculture,with emphasis on Vibrio cholerae and V.vulnificus,deserves special attention due to their role as potentially zoonotic aquaculture-associated pathogens.Furthermore,the intermediate susceptibility of V.vulnificus to ampicillin reflects the importance of monitoring drug use in prawn farming.

Clinical and environmental isolates of Burkholderia pseudomallei from Brazil: Genotyping and detection of virulence gene

Objective: To evaluate the genetic diversity of clinical and environmental isolates of Burkholderia pseudomallei(B.pseudomallei) recovered in Ceara, Brazil, and screen these isolates for the presence of type three secretion system virulence gene.Methods: Nineteen B.pseudomallei isolates(9 from clinical cases and 10 from soils)were analyzed.Random amplified polymorphic DNA was performed with primers OPQ-2, OPQ-4 and OPQ-16 to evaluate the genetic diversity, and type three secretion system gene was detected through polymerase chain reaction.Results: Random amplified polymorphic DNA showed a genetic relatedness of approximately 50% among the tested B.pseudomallei isolates, which were grouped into two clades, of which the biggest ones comprised 18/19 isolates for primer OPQ-2, and 17/19 isolates for primer OPQ-16.Primer OPQ-4 grouped the isolates into three clades comprising 1/19, 3/19 and 15/19 isolates.Additionally, type three secretion system gene was detected in all tested isolates.Conclusions: This is an effort to type B.pseudomallei strains from Ceara, which is important for better understanding this pathogen, contributing for the epidemiological surveillance of melioidosis in this endemic region.

Chlamydoconidium-producing Trichophyton tonsurans: Atypical morphological features of strains causing tinea capitis in Ceará, Brazil

Objective: To report atypical morphological features of Trichophyton(T.) tonsurans strains associated with tinea capitis. Methods: Eighty-two T. tonsurans strains isolated in Ceará, Brazil, were analyzed regarding macro and micromorphological features and nutritional patterns. Results: Fifty-two samples presented abundant chlamydoconidia, which were produced in chains. Macroscopically, these strains developed small glabrous colonies that were firmly attached to the surface of the culture medium, with few or no aerial mycelia and intense rusty yellow pigmentation. Seven strains did not grow with stimulus from thiamine. Samples were heterogeneous regarding urease production and none presented in vitro hair perforation. Conclusions: The observation of T. tonsurans strains with distinct phenotypic features indicates the need to revise the taxonomic criteria for routine identification of this dermatophyte.