Microbiological quality of fresh produce from open air markets and supermarkets in the Philippines.

This study is the first in the Philippines to conduct a comprehensive assessment of the prevalence of bacterial pathogens and somatic phages in retailed fresh produce used in salad preparation, namely, bell pepper, cabbage, carrot, lettuce, and tomato, using culture and molecular methods. Out of 300 samples from open air and supermarkets, 16.7% tested positive for thermotolerant Escherichia coli, 24.7% for Salmonella spp., and 47% for somatic phages. Results show that counts range from 0.30 to 4.03 log10 CFU/g for E. coli, 0.66 to ≥ 2.34 log10 MPN/g for Salmonella spp., and 1.30 to ≥ 3.00 log 10 PFU/g for somatic phages. Statistical analyses show that there was no significant difference in the microbial counts between open air and supermarkets (α = 0.05). TaqMan and AccuPower Plus DualStar real-time polymerase chain reaction (RT-PCR) was used to confirm the presence of these organisms. The relatively high prevalence of microorganisms observed in produce surveyed signifies reduction in shelf-life and a potential hazard to food safety. This information may benefit farmers, consumers, merchants, and policy makers for foodborne disease detection and prevention.

First report of Trichomonas tenax infections in the Philippines.

Recent studies have reported Trichomonas tenax as a cause of pleuropulmonary infections in humans. In this study, sputum and vaginal swab samples were collected from patients suffering from respiratory ailments in Rodriguez, Rizal and sex workers attending the social hygiene clinics in Angeles City in Pampanga, Mandaluyong City and Pasay City in Metro Manila, Philippines, respectively. DNA was extracted from samples and the 18S rRNA gene was amplified and sequenced. Phylogenetic trees were constructed using neighbor-joining, maximum-likelihood, maximum parsimony, and Bayesian inference analyses. Results showed that the new primer sets successfully amplified T. tenax from 14 sputum samples and Trichomonas vaginalis from 19 vaginal swab samples. Consequently, all isolates clustered with high bootstrap support and posterior probability values to their respective reference strains in the phylogenetic tree. Thus, the genus Trichomonas formed a highly supported clade with T. vaginalis in the first clade and T. tenax in the second clade. These findings conclude that T. vaginalis is solely present in the genito-urinary tract of females and that T. tenax can be found in the respiratory tract of humans. To our knowledge, this is the first report of detection and identification of T. tenax from sputum samples in the Philippines. However, further studies are still needed to determine the pathogenicity of this organism in humans.

New Hosts of Simplicimonas similis and Trichomitus batrachorum Identified by 18S Ribosomal RNA Gene Sequences.

Trichomonads are obligate anaerobes generally found in the digestive and genitourinary tract of domestic animals. In this study, four trichomonad isolates were obtained from carabao, dog, and pig hosts using rectal swab. Genomic DNA was extracted using Chelex method and the 18S rRNA gene was successfully amplified through novel sets of primers and undergone DNA sequencing. Aligned isolate sequences together with retrieved 18S rRNA gene sequences of known trichomonads were utilized to generate phylogenetic trees using maximum likelihood and neighbor-joining analyses. Two isolates from carabao were identified as Simplicimonas similis while each isolate from dog and pig was identified as Pentatrichomonas hominis and Trichomitus batrachorum, respectively. This is the first report of S. similis in carabao and the identification of T. batrachorum in pig using 18S rRNA gene sequence analysis. The generated phylogenetic tree yielded three distinct groups mostly with relatively moderate to high bootstrap support and in agreement with the most recent classification. Pathogenic potential of the trichomonads in these hosts still needs further investigation.

Molecular characterization of trichomonads isolated from animal hosts in the Philippines.

Trichomonads are amitochondrial anaerobic flagellated protists that are either parasites or commensals, generally living in the digestive or genitourinary tract of humans and animals. It has been reported that these protozoa can migrate to other sites in their target host, can adapt to new hosts, and are capable of zoonotic transmission. In this study, 59 trichomonad isolates from different animal hosts in the Philippines were identified and characterized. Primer sets were designed and were successful in amplifying the 18S rRNA gene sequences of the isolates. Phylogenetic trees were constructed using neighbor-joining (NJ), maximum parsimony (MP), maximum-likelihood (ML) and Bayesian inference (BI) analyses. Results showed that BLAST analysis of the isolates corresponded to the clustering of the isolates together with reference sequences in the constructed ML tree. Cattle and pig isolates were most likely Tetratrichomonas buttreyi, which were observed to be commensal in both animals. All duck and rooster isolates were similar with Tetratrichomonas gallinarum. All dog isolates together with single isolates from boa, goat, and owl were identical to Pentatrichomonas hominis. Occurrence of P. hominis in Boa constrictor imperator (boa) and Otus megalotis (Philippine scops owl) suggested the adaptation of the trichomonad to new hosts. Reptile hosts were observed to harbor Trichomitus batrachorum or Hypotrichomonas acosta. Three reptile isolates (Igu2, Igu4, and Liz7) suggest novel species belonging to Class Hypotrichomonadea. Furthermore, iguanas were infected with T. batrachorum or H. acosta. Trichomonads in animal hosts are commensal and the mode of transmission is via fecal-oral route. They are capable of adaptation to new hosts and therefore, zoonotic transmission is possible as well as pathogenesis in host. Thus, trichomonads can pose threats to the health of humans and animals.

Radiation inactivation of Paenibacillus larvae and sterilization of American Foul Brood (AFB) infected hives using Co-60 gamma rays.

The effectiveness of gamma radiation in inactivating the Philippine isolate of Paenibacillus larvae was investigated. Spores of P. larvae were irradiated at incremental doses (0.1, 0.2, 0.4, 0.8 and 1.6 kGy) of gamma radiation emitted by a 6°Co source. Surviving spores were counted and used to estimate the decimal reduction (D10) value. A dose of 0.2 kGy was sufficient to inactivate 90% of the total recoverable spores from an initial count of 105- 9 × 10³ spores per glass plate. The sterilizing effect of high doses of gamma radiation on the spores of P. larvae in infected hives was determined. In this study, a minimum dose (D(min)) of 15 kGy was tested. Beehives with sub-clinical infections of AFB were irradiated and examined for sterility. All the materials were found to be free of P. larvae indicating its susceptibility to γ-rays. After irradiation, there were no visible changes in the physical appearance of the hives' body, wax and frames. Thus, a dose of 15 kGy is effective enough for sterilization of AFB-infected materials.