ABSTRACT
This study aimed to identify lactic acid bacteria (LAB) in byproducts of fruit (Malpighia glabra L., Mangifera indica L., Annona muricata L., and Fragaria vesca L.) pulp processing. Fifty strains of LAB were identified using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequence (16S rRNA) analysis. Species belonging to Lactobacillus genus were the predominant LAB in all fruit pulp processing byproducts. The average congruency between the MALDI-TOF MS and 16S rRNA in LAB species identification reached 86%. Isolates of L. plantarum, L. brevis, L. pentosus, L. lactis and L. mesenteroides were identified with 100% congruency. MALDI-TOF MS and 16S rRNA analysis presented 86 and 100% efficiency of LAB species identification, respectively. Further, five selected Lactobacillus strains (L. brevis 59, L. pentosus 129, L. paracasei 108, L. plantarum 49, and L. fermentum 111) were evaluated for desirable probiotic-related properties and growth behavior on two different cultivation media. The exposure to pH 2.0 sharply decreased the counts of the different Lactobacillus strains after a 1 or 2 h incubation, while varied decreases were noted after 3 h of exposure to pH 3.0. Overall, the exposure to pH 5.0 and to bile salts (0.15, 0.30, and 1.00%) did not decrease the counts of the Lactobacillus strains. All tested Lactobacillus strains presented inhibitory activity against Staphylococcus aureus, Salmonella Typhimurium, Salmonella Enteritidis, Listeria monocytogenes and Escherichia coli, and presented variable susceptibility to different antibiotics. The selected Lactobacillus strains presented satisfactory and reproducible growth behavior. In conclusion, MALDI-TOF MS and 16S rRNA analysis revealed high efficiency and congruency for LAB species identification, and the selected Lactobacillus strains may be candidates for further investigation of novel probiotic strains.
Subject(s)
Drug Resistance, Bacterial , Enterobacteriaceae Infections/drug therapy , Providencia/isolation & purification , Selection, Genetic , Sepsis/drug therapy , beta-Lactamases/metabolism , Anti-Bacterial Agents/pharmacology , Enterobacteriaceae Infections/microbiology , Genes, Bacterial , Genotype , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Providencia/enzymology , Sepsis/microbiology , beta-Lactamases/geneticsABSTRACT
The present work reports the detection of the first case of nosocomial Klebsiella oxytoca producing class A carbapenemase KPC-2 in Brazil. The isolate KPN106 carried a 65-kb IncW-type plasmid that harbors the blaKPC gene and Tn4401b. Moreover, we detected the presence of a class 1 integron containing a new allele, arr-8, followed by a 5'-truncated dhfrIIIc gene. In view of the recent results, we emphasize the high variability of the bacterial and genetic hosts of this resistance determinant.
Subject(s)
Genes, Bacterial , Klebsiella oxytoca/enzymology , beta-Lactamases/genetics , Aged , Alleles , Brazil , DNA Transposable Elements , DNA, Bacterial/genetics , Drug Resistance, Bacterial , Fatal Outcome , Female , Genetic Variation , Humans , Integrons , Klebsiella Infections/diagnosis , Klebsiella Infections/drug therapy , Klebsiella oxytoca/drug effects , Klebsiella oxytoca/genetics , Klebsiella oxytoca/isolation & purification , Microbial Sensitivity Tests , Plasmids/genetics , Plasmids/metabolism , Polymyxin B/pharmacology , Rifampin/pharmacologyABSTRACT
The zinc finger motifs (Cys2His2) are found in several proteins playing a role in the regulation of transcripton. SmZF1, a Schistosoma mansoni gene encoding a zinc finger protein was initially isolated from an adult worm cDNA library, as a partial cDNA. The full sequence of the gene was obtained by subcloning and sequencing cDNA and genomic fragments. The collated gene sequence is 2181 nt and the complete cDNA sequence is 705 bp containing the full open reading frame of the gene. Analysis of the genome sequence revealed the presence of three introns interrupting the coding region. The open reading frame theoretically encodes a protein of 164 amino acids, with a calculated molecular mass of 18,667Da. The predicted protein contains three zinc finger motifs, usually present in transcription regulatory proteins. PCR amplification with specific primers for the gene allowed for the detection of the target in egg, cercariae, schistosomulum and adult worm cDNA libraries indicating the expression of the mRNA in these life cycle stages of S. mansoni. This pattern of expression suggests the gene plays a role in vital functions of different life cycle stages of the parasite. Future research will be directed to elucidate the functional role of SmZF1
Subject(s)
Animals , Cloning, Molecular , Genes, Helminth/genetics , Helminth Proteins/genetics , Schistosoma mansoni/genetics , Zinc Fingers/genetics , Base Sequence , DNA, Complementary , DNA-Binding Proteins , Gene Amplification , Gene Expression Regulation, Bacterial , Gene Library , Genes, Helminth/physiology , Genome, Bacterial , Polymerase Chain ReactionABSTRACT
Sm15 and Sm13 are recognized by antibodies from mice protectely vaccinated with tegumental membranes, suggesting a potencial role in protective immunity. In order to raise antibodies for immunochemical investigations, the genes for these antigens were expressed in pGEX and pMAL vectors so that comparisons could be made among different expression systems and different genes. The fusion proteins corresponding to several parts of the gene for the precursor of Sm15 failed in producing antibodies recognizing the parasite counterpart. On the other hand, antibodies raised against Sm13 MBP-fusion proteins recognized the 13 kDa tegumental protein. Thus the peculiarities of the gene of interest are important and the choice of the expression system must sometimes be decided on an impirical basis.
