Cloves is one of the main plantation commodities and is native to Indonesia. Leaf spot disease with necrosis symptom is often found in clove plants. Interferences to photosynthesis caused by leaf ...spot disease can cause plant death. Bacillus is known to inhibit the development of pathogens through nutrient competition and antibiosis mechanism. This study aims to identify Bacillus sp. RJ09 through molecular approach and determine its potential in suppressing the development of Pestalotiopsis sp., the cause of clove leaf spot by in vitro examination. Identification of the fungus was carried out by observing the morphology which included the color of the colony, the shape and size of the conidium of the isolated fungus. Identification of Bacillus sp. RJ09 was performed by polymerase chain reaction (PCR) using a pair of primers that amplified gyrB gene region of ±1400 bp, followed by sequence analysis. The ability of Bacillus sp. RJ09 as a biological agent against fungi associated with leaf spot was determined using an in vitro double culture method. Pestalotiopsis sp. was found as the fungus associated with leaf spot disease and can cause black necrotic spots on the leaves. Molecular identification of Bacillus sp. RJ09 showed the highest similarity value of 99.40% with B. subtilis subsp. subtitles. In vitro dual culture showed B. subtilis subsp. subtilis RJ09 can inhibit the growth of Pestalotiopsis sp. colonies by 75%.
BACKGROUND Tuberculosis (TB) is an infectious disease caused by the bacterium Mycobacterium tuberculosis, and the number of new cases of multidrug resistant TB (MDR-TB), pre extensively ...drug-resistant TB (pre-XDR-TB) and extensively drug-resistant TB (XDR-TB) has increased considerably worldwide. OBJECTIVES Herein, using 156 M. tuberculosis isolates from 106 patients previously classified as MDR or pre-XDR or XDR isolates, we investigated the genetic mutation profiles associated with phenotypic resistances in patients with MDR-TB, pre-XDR-TB and XDR-TB, treatment outcomes and resistance evolution. METHODS Molecular analyses were performed by partial sequencing of the rpoB, katG, gyrA, gyrB, rrs genes and analysis of the fabG-inhA promoter region. Clinical, epidemiologic and demographic data were obtained from the TB Notification database system of São Paulo (TB-WEB) and the Information System for Special Tuberculosis Treatments (SITE-TB). FINDINGS Drug resistance was attributed to previously known mutations and a novel Asp449Val mutation in gyrB was observed in four isolates from the same patient. Ten patients had more than one isolate evaluated and eight of these patients displayed resistance progression. MAIN CONCLUSIONS The present study is the first to report the frequency of mutations related to second-line drug resistance in MDR-TB, pre-XDR-TB and XDR-TB isolates. The results could lead to the improvement of available technologies for the rapid detection of drug resistant TB.
species often cause disease in farmed fish. In the present study, dominant bacteria were isolated from diseased crucian carp (
). Based on this, a bacterial isolate was tentatively named CFJY-623. ...This isolate was identified as
based on analysis of its morphological, physiological, and biochemical features, as well as 16S rRNA and
gene sequences. Six virulence genes related to pathogenicity including aerolysin, cytotonic enterotoxins, elastase, glycerophospholipid: cholesterol acyltransferase, lipase, and serine protease were identified in this
isolate. The median lethal dosage (LD50) of the CFJY-623 isolate for crucian carp was determined as 1.31 × 10
CFU/mL. Artificial experimental infection showed that the CFJY-623 isolate caused considerable histological lesions in the fish, including tissue cell degeneration, necrosis, and inflammatory cell infiltrating. Drug sensitivity testing showed that the isolate was susceptible to aminoglycosides, carbapenemes, and nitrofurans. Exploring its growing features showed that this isolate exhibited a high level of environmental adaptability. These results provided a scientific basis for the identification of
and treatment for fish infected by this pathogen.
In radiation-resistant bacteria belonging to the genus Deinococcus, transposition events of insertion sequences (IS elements) leading to phenotypic changes from a reddish color to white were detected ...following exposure to gamma irradiation and hydrogen peroxide treatment. This change resulted from the integration of IS elements into the phytoene desaturase gene, a key enzyme in the carotenoid biosynthesis pathway. To facilitate species identification and distinguish among Deinococcus strains, the gyrB gene encoding the B subunit of DNA gyrase was utilized. The s gnificance of the gyrB gene is well recognized not only in genome replication through the regulation of supercoiling but also in phylogenetic analysis providing support for 16S rRNA-based identification. Its mutation rate surpasses that of the 16S rRNA gene, offering greater resolution between closely related species, particularly those exhibiting >99% similarity. In this study, phylogenetic analysis was conducted comparing the 16S rRNA and gyrB gene sequences of Deinococcus species. Species-specific and genus-specific primers targeting Deinococcus species were designed and experimentally validated for selective amplification and rapid identification of the targeted species. This approach allows for the omission of 16S rRNA sequencing in the targeted Deinococcus species. Therefore, the gyrB gene is useful for identifying bacterial species and genus-level detection from individual microbes or microbial consortia using specialized primer sets for PCR amplification.
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•This manuscript has three important aspects following: firstly, the gyrB primer sets proved invaluable for the rapid and straightforward genus- and species-specific identification of Deinococcus strains, distinguishing them from bacteria of other genera.•Secondly, the phylogenetic tree exhibits higher resolution within gyrB gene than 16S rRNA of over 99% sequence identical Deinococcus genus.•Thirdly, exploring evolutionary aspects within the bacterial gyrB gene of the Deinococcus genus and other bacteria based on sequence variation and available structure models.
Novel antimicrobials for effective treatment of uncomplicated gonorrhea are essential, and the first-in-class, oral spiropyrimidinetrione DNA gyrase B inhibitor zoliflodacin appears promising. Using ...our newly developed Hollow Fiber Infection Model (HFIM), the pharmacodynamics of zoliflodacin was examined. A clinical zoliflodacin-susceptible
strain, SE600/18 (harbouring a GyrB S467N amino acid substitution; MIC = 0.25 mg/L), and SE600/18-D429N (zoliflodacin-resistant mutant with a second GyrB substitution, D429N, selected in the HFIM experiments; zoliflodacin MIC = 2 mg/L), were examined. Dose-range experiments, simulating zoliflodacin single oral dose regimens of 0.5, 1, 2, 3, and 4 g, were performed for SE600/18. For SE600/18-D429N, dose-range experiments, simulating zoliflodacin single oral 2, 3, 4, and 6 g doses, and zoliflodacin oral dose-fractionation experiments with 4, 6, and 8 g administered as q12 h were performed. Both strains grew well in the untreated HFIM growth control arms and mostly maintained growth at 10
-10
CFU/ml for 7 days. Zoliflodacin 3 and 4 g single dose oral regimens successfully eradicated SE600/18 and no growth was recovered during the 7-days experiments. However, the single oral 0.5, 1, and 2 g doses failed to eradicate SE600/18, and zoliflodacin-resistant populations with a GyrB D429N substitution were selected with all these doses. The zoliflodacin-resistant SE600/18-D429N mutant was not eradicated with any examined treatment regimen. However, this
-selected zoliflodacin-resistant mutant was substantially less fit compared to the zoliflodacin-susceptible SE600/18 parent strain. In conclusion, the rare clinical gonococcal strains with GyrB S467N substitution are predisposed to develop zoliflodacin resistance and may require treatment with zoliflodacin ≥3 g. Future development may need to consider the inclusion of diagnostics directed at identifying strains resistant or predisposed to resistance development at a population level and to strengthen surveillance (phenotypically and genetically), and possibly also at the patient level to guide treatment.
Antimicrobial resistance in
is an important global health concern. The genetically related commensal
act as a reservoir of resistance genes, and horizontal gene transfer (HGT) has been shown to play ...an important role in the genesis of resistance to cephalosporins and macrolides in
. In this study, we evaluated if there was evidence of HGT in the genes
and
responsible for fluoroquinolone resistance. Even though the role of
and
in quinolone resistance is unclear, the subunits
and
were included as zoliflodacin, a promising new drug to treat
targets the
subunit. We analyzed a collection of 20,047 isolates; 18,800
, 1,238 commensal
spp., and nine
. Comparative genomic analyses identified HGT events in genes,
,
,
, and
. Recombination events were predicted in
and
commensals.
,
, and
were identified as likely progenitors of the HGT events in
,
, and
, respectively.
The advent of high-throughput sequencing technologies in recent years has revealed the unexpected presence of genus Photobacterium within the chicken meat spoilage ecosystem. This study was ...undertaken to decipher the occurrence, the growth patterns and the genotypic biodiversity of Photobacterium phosphoreum on chicken breast fillets stored aerobically at 4 °C through conventional microbiological methods and molecular techniques. Samples were periodically cultured on marine broth agar (MA; supplemented with meat extract and vancomycin) for the enumeration of presumptive bioluminescent Photobacterium spp. In total, 90 bioluminescent bacteria were recovered from the initial (time of first appearance), middle and end stages of storage. Concomitantly, 95 total psychrotrophic/psychrophilic bacteria were isolated from the same medium to assess the presence and diversity of non-luminous photobacteria. Genetic diversity between bioluminescent isolates was assessed with two PCR-based DNA fingerprinting methods, i.e. RAPD and rep-PCR. Moreover, the characterization of selected bacterial isolates at the genus and/or species level was performed by sequencing of the 16S rRNA and/or gyrB gene. Bioluminescent bacteria were scarcely encountered in fresh samples at population levels of ca. 2.0 log CFU/g, whilst total psychrotrophic/psychrophilic bacteria were found at levels of ca. 4.4 log CFU/g. As time proceeded and close to shelf-life end, bioluminescent bacteria were encountered at higher populations, and were found at levels of 5.3 and 7.0 log CFU/g in samples from the second and third batch, respectively. In the first batch their presence was occasional and at levels up to 3.9 log CFU/g. Accordingly, total psychrotrophic/psychrophilic bacteria exceeded 8.4 log CFU/g at the end of storage, suggesting the possible underestimation of bioluminescent populations following the specific cultivation conditions. Sequence analysis assigned bioluminescent isolates to Photobacterium phosphoreum, while genetic fingerprinting revealed high intra-species variability. Respectively, total psychrotrophs/psychrophiles were assigned to genera Pseudomonas, Shewanella, Psychrobacter, Acinetobacter, Vibrio and Photobacterium. Non-luminous photobacteria were not identified within the psychrotrophs/psychrophiles. Results of the present study reveal the intra- and inter-batch variability on the occurrence and growth responses of P. phosphoreum and highlight its potential role in the chicken meat spoilage consortium.
•Insights into genetic variability of bioluminescent photobacteria in refrigerated chicken breast fillets.•P. phosphoreum levels varied within and between batches in fresh and spoiled samples.•P. phosphoreum population was found at levels potentially connected with spoilage processes.•Non-luminous photobacteria were not detected in spoilage microbiota.
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