Sex: Male
Education
Doctor of Veterinary Science and Medicine, Central Luzon State University, 2009
Bachelor of Science in Animal Husbandry, Central Luzon State University, 2007

Field of Specialization
Lentivirus
Amplification
Leptospirosis
Antibodies
Veterinary medicine

Researches

Article title: Prevalence and Characterization of Quinolone-Resistance Determinants in Escherichia coli Isolated from Food-Producing Animals and Animal-Derived Food in the Philippines
Authors: Lawrence Belotindos, Marvin A. Villanueva, Joel Miguel, Precious Bwalya, et al.
Publication title: Antibiotics 10(4):413, April 2021

Abstract:
Antimicrobial resistance to quinolones, which constitutes a threat to public health, has been increasing worldwide. In this study, we investigated the prevalence of quinolone-resistant determinants in Escherichia coli not susceptible to quinolones and isolated from food-producing animals and food derived from them, in the Philippines. A total of 791 E. coli strains were isolated in 56.4% of 601 beef, chicken, pork, egg, and milk samples, as well as environmental, cloacal, and rectal swab-collected samples from supermarkets, open markets, abattoirs, and poultry, swine, and buffalo farms. Using the disc diffusion method, it was determined that 78.6% and 55.4% of the isolates were resistant to at least one antimicrobial and multiple drugs, respectively. In 141 isolates not susceptible to quinolones, 115 (81.6%) harbored quinolone-resistant determinants and had mutations predominantly in the quinolone-resistance determining regions (QRDRs) of gyrA and parC. Plasmid-mediated, quinolone resistance (PMQR) and Qnr family (qnrA1, qnrB4, and qnrS1) genes were detected in all isolates. Forty-eight sequence types were identified in isolates harboring mutations in QRDR and/or PMQR genes by multilocus sequence typing analysis. Moreover, 26 isolates harboring mutations in QRDR and/or PMQR genes belonged mostly to phylogroup B1 and Enteroaggregative E. coli. In conclusion, a high prevalence of E. coli was found in food-producing animals and products derived from them, which could potentially spread high-risk clones harboring quinolone-resistance determinants.
Full text available upon request to the author

Article title: Evaluation of LAMP for detection and/or screening of Leptospira spp. infection among domestic animals in the Philippines
Authors: Gabriel Alexis SP. Tubalinal, Michelle M. Balbin, Marvin A. Villanueva, Clarissa Yvonne J. Domingo and Claro N. Mingala
Publication title: Journal of Advanced Veterinary and Animal Research 5(4): 459-465, December 2018

Abstract:
Objective:
This study assessed the applicability of loop-mediated isothermal amplification (LAMP) for the detection of leptospirosis among domesticated animals and sewage rats. Specifically, it evaluated the ability of LAMP to amplify Leptospira spp. targeting the 16s rRNA gene in boiled urine samples.

Materials and methods:
A total of 140 samples from different domestic animals were tested for the presence of the antigen. A nested-polymerase chain reaction (nPCR) protocol was used to compare and determine the sensitivity of LAMP in detecting Leptospira spp. The LAMP was also evaluated by comparing its amplification result using agarose gel electrophoresis and color change using dye.

Results:
Positivity rate of Leptospira spp. antigen was 29.0% (40/140) for LAMP and 9.3% (13/140) for nPCR. Also, LAMP results for gel electrophoresis and dye color change varied in some samples that may be due to the interpretation of the result in dye color change.

Conclusion:
Overall, LAMP is a rapid, sensitive, and cost-effective diagnostic method compared with nPCR. Also, LAMP has a potential application as pen-side screening, surveillance, and clinical diagnostic kits of infectious diseases without requiring advance equipment and skilled personnel.
Full text link https://tinyurl.com/kh22bvsw

Article title: Trypanosoma Evansi and Neospora Caninum Among Water Buffaloes (Bubalus Bubalis) in the Philippines
Authors: Claro Mingala, Jaypee Abenoja, Christopher V. Rivera, Michelle M Balbin, et al.
Publication title: Archives of Veterinary Science 25(1), March 2020

Abstract:
The study determined the positivity rate of Trypanosoma evansi and Neospora caninum antibodies in water buffaloes in the province of Nueva Ecija, Philippines using Polymerase Chain Reaction (PCR) for T. evansi and competitive Enzyme-linked Immunosorbent Assay (cELISA) for N. caninum antibodies. A total of 100 whole blood and 100 serum samples were collected to test for T. evansi and N. caninum, respectively. Rotat 1.2 VSG gene was target using PCR for T. evansi detection. Neospora caninum antibody detection was done from the serum samples using cELISA test kit. Results revealed that the positivity rate of T. evansi in Nueva Ecija was 11% (11/100). The positive animals identified were from the municipalities of Muñoz (4/16; 25%), Sta. Rosa (3/13; 23.08%) and Talugtug (4/16; 25%). The seropositive rate of Nueva Ecija for N. caninum. was 46% (46/100), seropositive animals were identified in Cabanatuan City, 57.14% (4/7); Science City of Muñoz, 43.14% (22/51); Sta. Rosa, 40% (4/10); Sto. Domingo, 50% (6/12); and Talugtug 50% (10/20). The seropositivity rate of N. caninum and the presence of T. evansi in Nueva Ecija may contribute to the cases of abortions in the province and further studies should be employed to confirm the association of these organisms to abortion cases on water buffaloes.
Full text link https://tinyurl.com/uzwf5u95

Article title: Characterization of drug resistance-associated TevAT1 gene of Trypanosoma evansi from Philippine water buffaloes (Bubalus bubalis)
Authors: Claro Mingala, Alma Corazon P. Pasag, Marvin Bryan Segundo Salinas, Michelle M Balbin, et al.
Publication title: Annals of Parasitology 65(4): 381-386, January 2019

Abstract:
This study detected and characterized the TevAT1 gene of Trypanosoma evansi isolates from Philippine water buffaloes (Bubalus bubalis). A total of 68 blood samples from Philippine water buffaloes were subjected to DNA extraction and PCR assay was performed using RoTat 1.2 gene to detect T. evansi. Those samples positive for T. evansi subsequently underwent another PCR assay to detect the presence of TevAT1 gene. Trypanosoma evansi was detected in 26.47% (18/68) blood samples in which distributed throughout the main islands of the country (4 from Luzon, 2 from Visayas and 12 from Mindanao). However, only 10 of these samples were positive for TevAT1 gene. Sequence alignment of the TevAT1 gene from local isolates showed no single nucleotide polymorphisms when compared to other strains in various countries. Those T. evansi without the gene of interest could be possibly resistant to some trypanocidal drugs but this needs to be further investigated in-vitro or in-vivo.
Full text link https://tinyurl.com/yw42kuxm

Article title: Molecular epidemiology of pathogenic Leptospira spp. among large ruminants in the Philippines
Authors: Marvin A. Villanueva, Claro Mingala, Michelle M. Balbin, Chie NAKAJIMA, et al.
Publication title: Journal of Veterinary Medical Science 78(11), July 2016

Abstract:
The extent of Leptospira infection in large ruminants resulting to economic problems in livestock industry in a leptospirosis-endemic country like the Philippines has not been extensively explored. Therefore, we determined the prevalence and carrier status of leptospirosis in large ruminants using molecular techniques and assessed the risk factors of acquiring leptospirosis in these animals. Water buffalo and cattle urine samples (n=831) collected from 21 farms during 2013–2015 were subjected to flaB-nested PCR to detect pathogenic Leptospira spp. Leptospiral flaB was detected in both species with a detection rate of 16.1%. Leptospiral DNA was detected only in samples from animals managed in communal farms. Sequence analysis of Leptospira flaB in large ruminants revealed the formation of three major clusters with L. borgpetersenii or L. kirschneri. One farm contained LeptospiraflaB sequences from all clusters identified in this study, suggesting this farm was the main source of leptospires for other farms. This study suggested that these large ruminants are infected with various pathogenic Leptospira species causing possible major economic loss in the livestock industry as well as potential Leptospira reservoirs that can transmit infection to humans and other animals in the Philippines.
Full text link https://tinyurl.com/ns2r72av

Article title: Development and evaluation of an interferon-γ release assay in Asian elephants (Elephas maximus)
Authors: Sarad Paudel, Marvin A. Villanueva, Susan Mikota, Chie NAKAJIMA, et al.
Publication title: Journal of Veterinary Medical Science 78(7), March 2016

Abstract:
We developed an interferon-γ release assay (IGRA) specific for Asian elephants (Elephas maximus). Whole blood collected from forty captive Asian elephants was stimulated with three different mitogens i.e., phytohemagglutinin (PHA), pokweed mitogen (PWM) and phorbol myristate aceteate/ionomycin (PMA/I). A sandwich ELISA that was able to recognize the recombinant elephant interferon-γ (rEIFN-γ) as well as native interferon-γ from the Asian elephants was performed using anti-elephant IFN-γ rabbit polyclonal antibodies as capture antibodies and biotinylated anti-elephant IFN-γ rabbit polyclonal antibodies as detection antibodies. PMA/I was the best mitogen to use as a positive control for an Asian elephant IGRA. The development of an Asian elephant-specific IGRA that detects native IFN-γ in elephant whole blood provides promising results for its application as a potential diagnostic tool for diseases, such as tuberculosis (TB) in Asian elephants.
Full text link https://tinyurl.com/5f5xyjvc

Article title: Serological investigation of Leptospira infection and its circulation in one intensive-type water buffalo farm in the Philippines
Authors: Marvin A. Villanueva, Claro N. Mingala, Nina G. Gloriani, Yasutake Yanagihara, et al.
Publication title: Japanese Journal of Veterinary Research 64(1): 15-24, 2016

Abstract:
Water buffalo is an indispensable livestock in the Philippines. Leptospirosis is a serious zoonosis that can be fatal to humans and cause reproductive problems in livestock. Leptospirosis has been reported in some countries where water buffaloes are commercially raised, highlighting the Leptospira prevalence in this farming system, but information on leptospirosis in water buffalo farms in the Philippines is limited. In this study, we collected blood samples from rats (n ＝ 21), and water buffaloes (n ＝ 170) from different groups and locations in one intensive-type buffalo farm in the Philippines. Serum was analyzed by microscopic agglutination test (MAT). Anti-Leptospira antibodies reacting with serogroups Canicola, Icterohaemorrhagiae and Pomona were found in sera of 30% tested rats, and 48% of water buffalo sera tested positive for at least one Leptospira strain, in which serogroups
Full text link https://tinyurl.com/numbz2rp

Article title: Molecular epidemiological survey and genetic analysis of vector-borne infections of cattle in Luzon Island, the Philippines
Authors: Nyamsuren Ochirkhuu, Satoru Konnai, Claro Mingala, Tomohiro Okagawa, et al.
Publication title: Veterinary Parasitology 212(3), June 2015

Abstract:
In the Philippines, vector-borne disease is one of the important problems in the livestock industry. To elucidate the epidemiology of vector-borne diseases in cattle on Luzon Island, the Philippines, the prevalence of five protozoan agents was assessed by polymerase chain reaction. Out of the 339 samples, 324 (95.5%), 154 (45.4%), 209 (61.6%), 140 (41.3%), and 2 (0.6%) were positive for Anaplasma marginale, Babesia bigemina, Babesia bovis, Theileria spp., and Trypanosoma evansi infections, respectively. Mixed infections were detected in 290 (85.5%) samples, of which 115 (33.9%) had two pathogens, 144 (42.5%) had three pathogens, and 31 (9.1%) had four kinds of pathogens. 16S rRNA gene was 100% identical in A. marginale compared with the same lineage across the world. B. bovis RAP-1 and B. bigemina AMA-1 genes were identical with 92.27%-100% and 97.07%-100% sequences, respectively, in the database (Asian isolates). MPSP genes of Theileria spp. were 83.51%-100% identical with the one another. Phylogenetic analysis showed that they belong to the groups of T. sergenti and T. buffeli. Positive rates of the tick-borne pathogens were extremely high in this area. These findings provide vital information that can be used for the planning and execution of effective control measures for vector-borne diseases in the Philippine cattle industry. Copyright © 2015 Elsevier B.V. All rights reserved.
Full text link https://tinyurl.com/cvawcrap

Article title: The great diversity of major histocompatibility complex class II genes in Philippine native cattle
Authors: S.N. Takeshimaa, T. Miyasakaa, M. Polata, M. Kikuya, et al.
Publication title: Meta Gene 2(1), December 2014

Abstract:
Bovine leukocyte antigens (BoLA) are extensively used as markers for bovine disease and immunological traits. However, none of the BoLA genes in Southeast Asian breeds have been characterized by polymerase chain reaction (PCR)-sequence-based typing (SBT). Therefore, we sequenced exon 2 of the BoLA class II DRB3 gene from 1120 individual cows belonging to the Holstein, Sahiwal, Simbrah, Jersey, Brahman, and Philippine native breeds using PCR-SBT. Several cross-breeds were also examined. BoLA-DRB3 PCR-SBT identified 78 previously reported alleles and five novel alleles. The number of BoLA-DRB3 alleles identified in each breed from the Philippines was higher (71 in Philippine native cattle, 58 in Brahman, 46 in Holstein × Sahiwal, and 57 in Philippine native × Brahman) than that identified in breeds from other countries (e.g., 23 alleles in Japanese Black and 35 in Bolivian Yacumeño cattle). A phylogenetic tree based on the DA distance calculated from the BoLA-DRB3 allele frequency showed that Philippine native cattle from different Philippine islands are closely related, and all of them are closely similar to Philippine Brahman cattle but not to native Japanese and Latin American breeds. Furthermore, the BoLA-DRB3 allele frequency in Philippine native cattle from Luzon Island, located in the Northern Philippines was different from that in cattle from Iloilo, Bohol, and Leyte Islands, which are located in the Southern Philippines. Therefore, we conclude that Philippine native cattle can be divided into two populations, North and South areas. Moreover, a neutrality test revealed that Philippine native cattle from Leyte showed significantly greater genetic diversity, which may be maintained by balancing selection. This study shows that Asian breeds have high levels of BoLA-DRB3 polymorphism. This finding, especially the identification of five novel BoLA-DRB3 alleles, will be helpful for future SBT studies of BoLA-DRB3 alleles in East Asian cattle.
Full text available upon request to the author

Article title: Molecular detection and characterization of Theileria species in the Philippines
Authors: Lawrence P. Belotindos, Jonathan V. Lazaro, Marvin A. Villanueva and Claro N. Mingala
Publication title: Acta Parasitologica 59(3):448-53, September 2014

Abstract:
Theileriosis is a tick-borne disease of domestic and wild animals that cause devastating economic loss in livestock in tropical and subtropical regions. Theileriosis is not yet documented in the Philippines as compared to babesiosis and anaplasmosis which are considered major tick-borne diseases that infect livestock in the country and contribute major losses to the livestock industry. The study was aimed to detect Theileria sp. at genus level in blood samples of cattle using polymerase chain reaction (PCR) assay. Specifically, it determined the phylogenetic relationship of Theileria species affecting cattle in the Philippines to other Theileria sp. registered in the GenBank. A total of 292 blood samples of cattle that were collected from various provinces were used. Theileria sp. was detected in 43/292 from the cattle blood samples using PCR assay targeting the major piroplasm surface protein (MPSP) gene. DNA sequence showed high similarity (90-99%) among the reported Theileria sp. isolates in the GenBank and the Philippine isolates of Theileria. Phylogenetic tree construction using nucleotide sequence classified the Philippine isolates of Theileria as benign. However, nucleotide polymorphism was observed in the new isolate based on nucleotide sequence alignment. It revealed that the new isolate can be a new species of Theileria.
Full text link https://tinyurl.com/5sc3s5xc

Article title: Concordance of competitive enzyme linked immunosorbent assay and nested-polymerase chain reaction in the detection of caprine arthritis-encephalitis virus
Authors: Justin Christian V. Gonzales, Clarissa Yvonne Jueco Domingo, Nancy S. Abes, Charito A. Gutierrez, et al.
Publication title: Small Ruminant Research 115(1-3):134-139, October 2013

Abstract:

The study detected the presence of caprine arthritis-encephalitis virus (CAEV) in blood samples from 262 goats and compared the results using competitive enzyme linked immunosorbent assay (cELISA) and nested-polymerase chain reaction (nested-PCR) assay. Moreover, it determined the agreement using kappa (κ) statistic, analyze the genetic sequence of CAEV and describe the histopathologic features using carpal joint, brain, lung and mammary gland samples of CAEV positive animals. CAEV antibodies were detected in 15/262 (5.73%) of goat serum samples using cELISA, based on the use of monoclonal antibody binding to CAEV gp135 or SU glycoprotein. In nested-PCR assay targeting the CAE proviral gag region, 9/262 (3.44%) goats were positive which increased the number of positive animals detected to 19 (7.25%). Kappa statistic showed fair agreement between cELISA and nested PCR (κ=0.39). DNA sequence of PCR product showed 91–98% homology among the reported CAEV genome in the GenBank. Histopathological findings were characterized by varying degrees of mononuclear cell infiltrations that conformed to the typical features of lentivirus infection.
Full text available upon request to the author

Article title: A new loop-mediated isothermal amplification method for rapid, simple, and sensitive detection of Leptospira spp. in urine
Authors: Nobuo Koizumi, Chie Nakajima, Tsunehito Harunari, Tsutomu Tanikawa, et al.
Publication title: Journal of Clinical Microbiology 50(6): 2072-2074, June 2012

Abstract:
We developed a new loop-mediated isothermal amplification (LAMP) method to detect rrs, a 16S rRNA gene of pathogenic Leptospira spp. in urine. The method enables detection of two leptospiral cells per reaction mixture following boiling of urine specimens. The sensitivity of this method is higher than that of culture or of flaB nested PCR.
Full text available upon request to the author

Article title: Incidence and risk factors of Cryptosporidium spp. infection in water buffaloes confined in a communal management system in the Philippines
Authors: Marvin A. Villanueva, Clarissa Yvonne J. Domingo , Nancy S. Abes , Claro N. Mingala
Publication title: The Internet Journal of Veterinary Medicine 2010 : Volume 8 Number 1

Abstract:
The study determined the incidence ofcryptosporidiosis (Cryptosporidium spp.) among water buffaloes in a confined management setting in the Philippines. Detection of oocysts in the feces of symptomatic and asymptomatic calves and their respective dams was performed using microscopy. The incidence proportion and density of the infection, the percentage distribution in calves according to sex and stool consistency, and the presence of association between several hypothesized risk factors such as birth weight, history of diarrhea and parasitologic state of the dam were described. Fecal samples from 38 Murrah buffalo calves were collected at 6 a.m. at days 4, 8 and 12 within the two-week observation period from day of birth. The fecal samples were processed using formalin-ether concentration technique, stained with Kinyoun acid fast and viewed under the microscope. Results showed that 10 out of 38 dams and one out of 38 buffalo calves were positive for Cryptosporidium spp. oocysts. The incidence proportion was 0.0263 for the 12-day observation period or three per 100 calves. The incidence rate or density was 2.2 per 1000 calf-days at risk with a point prevalence of 5%. Starting at day eight, 50% was diagnosed with Cryptosporidium spp. oocysts based on the stool consistency. However, test of association showed no sufficient evidence that cryptosporidiosis in neonatal calves was dependent on gender, birth weight and parasitologic state of the dam after delivery. Results of the test of association of these risk factors were undefined.
Full text link https://tinyurl.com/jcpuj35n