Genome drafts of Pseudogracilibacillus spp. from soil and sediment of Mount Makiling, a dormant volcano in the Philippines.

We present the draft whole-genome sequences of Pseudogracilibacillus spp. isolated from the soils and sediments of Sipit Creek located at Mount Makiling, a dormant volcano in the southern part of Luzon Island, Philippines. This Pseudogracilibacillus spp. genome report extends the body of knowledge on a lesser-known genus of Bacillaceae.

Differential antigenicity of individual Mycoplasma hyorhinis variable lipoproteins.

The Mycoplasma hyorhinis (Mhr) variable lipoprotein (Vlp) family, comprising Vlps A, B, C, D, E, F, and G, are highly variable in expression, size, and cytoadhesion capabilities across Mhr strains. The 'Vlp system' plays a crucial role in cytoadhesion, immune evasion, and in eliciting a host immunologic response. This pilot study described the development of Vlp peptide-based ELISAs to evaluate the antigenic reactivity of individual Vlps against Mhr antisera collected throughout a longitudinal study focused on Mhr strain 38983, reproducing Mhr-associated disease under experimental conditions. Specifically, serum samples were collected at day post-inoculation 0, 7, 10, 14, 17, 21, 24, 28, 35, 42, 49, and 56 from Mhr- and mock (Friis medium)-inoculated cesarean-derived, colostrum-deprived pigs. Significant Mhr-specific IgG responses were detected at specific time points throughout the infection, with some variations for each Vlp. Overall, individual Vlp ELISAs showed consistently high accuracy rates, except for VlpD, which would likely be associated with its expression levels or the anti-Vlp humoral immune response specific to the Mhr strain used in this study. This study provides the basis and tools for a more refined understanding of these Vlp- and Mhr strain-specific variations, which is foundational in understanding the host immune response to Mhr.

Dynamics of antibody response and bacterial shedding of Mycoplasma hyorhinis and M. hyosynoviae in oral fluids from experimentally inoculated pigs.

Mycoplasma hyorhinis (Mhr) and M. hyosynoviae (Mhs) are commensal organisms of the upper respiratory tract and tonsils but may also cause arthritis in pigs. In this study, 8-week-old cesarean-derived colostrum-deprived (CDCD) pigs (n = 30; 3 groups, 10 pigs per group, 2 pigs per pen) were inoculated with Mhr, Mhs, or mock-inoculated with culture medium and then pen-based oral fluids were collected at different time points over the 56 days of the experimental study. Oral fluids tested by Mhr and Mhs quantitative real-time PCRs revealed Mhr DNA between day post inoculation (DPI) 5-52 and Mhs DNA between DPI 5-15. Oral fluids were likewise tested for antibody using isotype-specific (IgG, IgA, IgM) indirect ELISAs based on a recombinant chimeric polypeptide of variable lipoproteins (A-G) for Mhr and Tween 20-extracted surface proteins for Mhs. Mhr IgA was detected at DPI 7 and, relative to the control group, significant (p < 0.05) antibody responses were detected in the Mhr group between DPI 12-15 for IgM and DPI 36-56 for both IgA and IgG. In the Mhs group, IgM was detected at DPI 10 and significant (p < 0.05) IgG and IgA responses were detected at DPI 32-56 and DPI 44-56, respectively. This study demonstrated that oral fluid could serve as an effective and convenient antemortem sample for monitoring Mhr and Mhs in swine populations.

Metataxonomic Characterization of Enriched Consortia Derived from Oil Spill-Contaminated Sites in Guimaras, Philippines, Reveals Major Role of Klebsiella sp. in Hydrocarbon Degradation.

Oil spills are major anthropogenic disasters that cause serious harm to marine environments. In the Philippines, traditional methods of rehabilitating oil-polluted areas were proven to be less efficient and cause further damage to the environment. Microbial degradation has poised itself to be a promising alternative to those traditional methods in remediating oil spills. Hence, the present study aimed to enrich and characterize hydrocarbon-degrading microbial consortia from oil-contaminated regions in Guimaras Island for potential use in bioremediation. A total of 75 soil samples were obtained and used as inoculum for the enrichment for hydrocarbon degraders. Afterwards, 32 consortia were recovered and subjected to the 2,6-DCPIP assay for biodegradation ability on four types of hydrocarbons: diesel, xylene, hexane, and hexadecane. The consortia that obtained the highest percent degradation for each of the four hydrocarbons were "B2" (92.34% diesel degraded), "A5" (85.55% hexadecane degraded), "B1" (74.33% hexane degraded), and "B7" (63.38% xylene degraded). Illumina MiSeq 16S rRNA gene amplicon sequencing revealed that the dominant phyla in all consortia are Pseudomonadota (previously Proteobacteria), followed by Bacillota (previously Firmicutes). Overall, the amplicon sequence variants (ASVs) retrieved were mainly from the Gammaproteobacteria class, in which many hydrocarbon-degrading bacteria are found. Predictive functional profiling of the consortium showed the presence of genes involved in the degradation of recalcitrant hydrocarbon pollutants. Fatty acid metabolism, which includes alkB (alkane-1-monooxygenase) and genes for beta oxidation, was inferred to be the most abundant amongst all hydrocarbon degradation pathways. Klebsiella sp. is the predominant ASV in all the sequenced consortia as well as the major contributor of hydrocarbon degradation genes. The findings of the study can serve as groundwork for the development of hydrocarbon-degrading bacterial consortia for the bioremediation of oil spill-affected areas in the Philippines. Likewise, this paper provides a basis for further investigation into the role of Klebsiella sp. in the bioremediation of hydrocarbon pollutants.

The broad-spectrum rice blast resistance (R) gene Pita2 encodes a novel R protein unique from Pita.

BACKGROUND: Rice blast is generally considered the most devastating rice disease worldwide. The development of resistant varieties has been proven to be the most economical strategy to control the disease. A cluster of resistant (R) genes on rice chromosome 12 including Pita, Pita2 and Ptr has been studies for decades. However, the relationship between these R genes has not been well established. RESULTS: In this study, we compared the resistance spectra controlled by Pita2 and Pita by testing their monogenic lines (MLs) in four hotspots found in the Philippines and Burundi from 2014 to 2018. The reaction patterns were distinct in two countries and that Pita2-mediated field resistance was relatively prevalent. Pathogenicity tests using 328 single-spore isolates in greenhouse further verified that IRBLta2-Re for Pita2 conferred a relatively broader spectrum resistance than those of Pita. Rough and fine mapping of Pita2 were conducted using F2 and F3 populations derived from IRBLta2-Re [CO] and CO 39 consisting of 4344 progeny to delimit Pita2 in a genomic interval flanked by two markers 12 g18530 and 12 g18920 proximal to the centromere of chromosome 12. Alignment of the markers to the genomic sequence of IR64, which harbors Pita2 verified by genetic analysis, approximately delimited the candidate gene(s) within 313-kb genomic fragment. The two Pita2 suppressive mutants that contain mutations within Pita2 were verified and identified. Comparative sequence analysis in these two mutants further identified that each individual allele contains a single nucleotide substitution at a different position resulting in nonsense and missense mutations in the protein product of LOC_Os12g18729. On the contrary, no sequence mutation was detected in other candidate genes, indicating that mutations in LOC_Os12g18729 were responsible for the loss of function of Pita2. Pita2 encodes a novel R protein unique from Pita, which is exactly identical to the previously cloned Ptr. Moreover, based on the resistance gene analysis of rice varieties and mutants containing Pita, it was found that Pita2 rather than Pita was responsible for the specificity to some differential isolates with AvrPita. The diagnosis and survey of Pita2 in IRRI released varieties showed relatively low frequency, implying a high value of its application for breeding resistant varieties against rice blast via marker assisted selection. CONCLUSION: Our study clarified the relationship between Pita, Pita2 and Ptr. Pita2 is identical to Ptr and distinct from Pita in both sequence and chromosomal location although Pita2 and Pita are genetically linked to each other. The loss of function of Pita2 but not Pita eliminate the specificity to some AvrPita containing isolates, however, the mechanism underlying the recognition between Pita2/Pita and AvrPita remains elusive.

Physiology and posttranscriptional regulation of methanol:coenzyme M methyltransferase isozymes in Methanosarcina acetivorans C2A.

Methanosarcina species possess three operons (mtaCB1, mtaCB2, and mtaCB3) encoding methanol-specific methyltransferase 1 (MT1) isozymes and two genes (mtaA1 and mtaA2) with the potential to encode a methanol-specific methyltransferase 2 (MT2). Previous genetic studies showed that these genes are differentially regulated and encode enzymes with distinct levels of methyltransferase activity. Here, the effects of promoter strength on growth and on the rate of methane production were examined by constructing strains in which the mtaCB promoters were exchanged. When expressed from the strong PmtaC1 or PmtaC2 promoter, each of the MtaC and MtaB proteins supported growth and methane production at wild-type levels. In contrast, all mtaCB operons exhibited poorer growth and lower rates of methane production when PmtaC3 controlled their expression. Thus, previously observed phenotypic differences can be attributed largely to differences in promoter activity. Strains carrying various combinations of mtaC, mtaB, and mtaA expressed from the strong, tetracycline-regulated PmcrB(tetO1) promoter exhibited similar growth characteristics on methanol, showing that all combinations of MtaC, MtaB, and MtaA can form functional MT1/MT2 complexes. However, an in vitro assay of coupled MT1/MT2 activity showed significant variation between the strains. Surprisingly, these variations in activity correlated with differences in protein abundance, despite the fact that all the encoding genes were expressed from the same promoter. Quantitative reverse transcriptase PCR and reporter gene fusion data suggest that the mtaCBA transcripts show different stabilities, which are strongly influenced by the growth substrate.