Virulence genes detection among the antibiotic resistant Enterococcus faecalis isolated from bird industry in Borneo

The abuse of antibiotics usage in bird industry has resulted in the emerging antibiotic resistant Enterococci worldwide which has posed a threat clinically to human health. The present study was to screen and identify the potential virulence agents in antibiotic resistance E. faecalis in bird industry in Borneo. Enterococcus bacteria collected from the birds’ faeces and indoor air inside ten birdhouses were identified to species level and their antibiotic resistance was checked using antibiotic susceptibility discs. Specific primers using PCR assay were intended for the detection of four potential virulence genes (ace, AS, efaA, gelE). Out of the thirty-seven Enterococci faecal bacteria, the prevailing bacteria found were Enterococcus qallinacum (51%), Enterococcus faecalis (35%) and Enterococcus harae (8%). The airborne bacteria were reported as Enterococcus faecalis (5%) and Enterococcus qallinacum (1%). Twenty-seven percent of isolates were reported to have Multiple Antibiotic Resistance (MAR) index ≥ 0.2 with 9 distinct resistance patterns formed. E. faecalis showed higher resistance to vancomycin. Virulence genes were successfully reported in the 15 E. faecalis isolates. Sixty-seven percent of isolates were detected positive for four virulence genes, 27% possessed three (AS, efaA, gelE) genes and 6% possessed two (ace, AS) genes. Antibiotic resistance and virulence genes detection were significantly correlated. These virulence genes or antibiotic resistance genes were important in the pathogenesis of E. faecalis infections

Dispersion pattern and sampling plan for Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae) in a citrus orchard

The ecology of the psyllid and its spatial distribution as the basis for the development of a reliable sampling plan are very important. The abundance and spatial distribution of Diaphorina citri (Hemiptera: Psyllidae) were studied in a commercial citrus orchard in southwestern Sarawak, Malaysia from April 2013 to December 2014. The spatial distribution of D. citri eggs, nymphs and adults were analysed using Taylor’s power law and Iwao’s patchiness regression. Taylor’s power law fitted the data better and produced higher values of R2 than Iwao’s regression model but did not work well with the egg populations. Based on both regression models, the field dispersion patterns of D. citri eggs, nymphs and adults were aggregated among flush shoots in individual trees as indicated by the regression slopes that were significantly >1. By homogeneity tests on both regression methods, the slopes of Taylor’s power law and Iwao’s regression model did not differ significantly for the D. citri population on honey tangerine for both years. The minimum number of flush shoots per tree required for estimates of D. citri densities varied from 2, 4 and 6 flush shoots for adults, nymphs and eggs, respectively, for the average density of each developmental stage obtained during our studies. Prediction suggested that a sampling plan consisting of 10 trees with the optimum number of six flush shoots per tree was required for a reasonably accurate density estimation of the three life stages of D. citri acceptable enough for population studies and pest management program in citrus orchards

In vivo fecundity evaluation of Phaleria macrocarpa extract supplementation in male adult rats

"Mahkota Dewa" fruit (Phaleria macrocarpa [Scheff.] Boerl.), is a traditional Indonesian plant-based remedy that has been used traditionally for generations in treating multiple illness and diseases. This investigation intends to assess the fecundity effects of P. macrocarpa supplementation in adult male rats through hormonal, physical and histological changes. Sixty male Sprague Dawley rats were randomly distributed into two by five experimental design with two supplementation periods (3 and 7 weeks) allotted to 5 different doses of extract (0, 24, 48, 240 mg PM aqueous extract/ kg bw and 80 mg of commercial PM product/ kg bw). The mean sperm count (455 cells/ml), body weight (301 g), histological assessment of spermatogonia cells (87 cells), and thickness of seminiferous tubule layer (79 µm) significantly increased (P < 0.05) in rats treated with 240 mg/ kg dose. However, there were no changes in both physical appearances of testes (size and volume) and testosterone hormone levels among the treatment groups. Our findings indicated that supplementation of P. macrocarpa significantly increased the fecundity of rats and the effect was dose and time-dependent. The study suggested that P. macrocarpa offered an attractive and alternative potential for improving the fertility in men

Genotypic profiles of virulent genes detected among the Enterococcus faecalis,Escherichia coli, Pseudomonas aeruginosa isolated from swiftlets in Borneo

Aims: The occurrence of multiple pathogenic Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa are important nosocomial and hazardous infection clinically challenge worldwide. Thus, the aim of this study was to screen for the virulent genes profiles to ascertain their prevalence in swiftlets in Borneo. Methodology and results: The Enterococci, E. coli and P. aeruginosa bacteria were isolated from the swiftlets’ faeces and air inside swiftlet houses, which located in the Southern, Central and Northern regions of Borneo. The isolates were identified to the species level by 16S rRNA sequencing assay. Specific primers were designed for detection of the potential virulence genes in E. faecalis (ace, AS, efaA and gelE), E. coli (stx) and P. aeruginosa (oprL) by PCR assay. A total of 38 Enterococci, 26 of E. coli and 2 of P. aeruginosa fecal and airborne bacteria were identified. Sixty-seven percent of E. faecalis isolates were detected positive for four virulence genes, 27% possessed three (AS, efaA, gelE) genes and 6% possessed two (ace, AS) genes. There were no stx genes detected among all the E. coli isolates. The oprL gene was detected in all the P. aeruginosa isolates. Conclusion, significance and impact of study: Virulence genes are important in the pathogenesis of both clinical and avian infections which considered to be a serious public health threat. The high incidence of virulence genes detection in E. faecalis and P. aeruginosa indicates these genes were widely disseminated among the bacteria found in swiftlet houses, suggesting the important issues in the pathogenesis of infections and diseases which may cause potential health risks to humans

Characterization and evaluation of fungicides for control of Phytophthora palmivora on cocoa (Theobroma cacao)

Studies were conducted to characterize and evaluate selected fungicides against Phytophthora palmivora on cocoa (Theobroma cacao) from Sarawak, Malaysia. Based on morphological characteristics and molecular data (sequence analysis of internal transcribed spacer region and phylogenetic analysis), the causal pathogen was identified as P. palmivora. Fungicides, including copper oxychloride, metalaxyl, benzalkonium chloride, and a biofertilizer, Bacillus subtilis were evaluated for their ability to inhibit the mycelium growth of P. palmivora isolates. Benzalkonium chloride and metalaxyl exhibited 100% inhibitory effect against P. palmivorain vitro, at effective concentration (EC50) of 0.2% and 0.3 μg/mL, respectively. B. subtilis and copper oxychloride provided over 85% efficacy, with EC50 estimated at 0.35% and 1500 μg/mL, respectively. Therefore, benzalkonium chloride and B. subtilis are a good alternative for rotation with the commonly used active ingredients (metalaxyl and copper oxychloride) for P. palmivora control and management of resistance. The in vitro study has demonstrated good control of P. palmivora but in vivo study is required to account the environment factor and systemic response of the plant

Effect of horticultural mineral oil on Huanglongbing transmission by Diaphorina citri Kuwayama (Hemiptera: Psyllidae) population in a commercial citrus orchard in Sarawak, Malaysia, Northern Borneo

Diaphorina citri Kuwayama transmits a destructive citrus disease caused by a fastidious bacterium ‘Candidatus Liberibacter asiaticus’ (CLas) designated as Huanglongbing (HLB) which posed a risk of detrimental threat to the Malaysian citrus industry. All D. citri life stages show a lumped habit on young flushes and its population fluctuations was closely related to accessibility of young flushes. The study aimed to investigate if the appearance of young flush shoots on citrus influences ACP population fluctuation and if horticultural mineral oil (HMO) could reduce spread of HLB transmission by ACP in a commercial healthy orchard. Field research was carried out from 1 April 2011 to 1 December 2014 in a 2-year-old 1 ha citrus farm that consisted of 200 PCR-certified disease-free grafted non-bearing honey tangerine (Citrus reticulata L.) in southwestern Sarawak, Malaysia. The experiment had two treatments namely control (unsprayed) and nC24 HMO with four replications arranged in a simple randomized block design. ACP eggs, nymphs, and adults per flush shoot was assessed and HLB incidence was monitored for visual inspection of the citrus trees for the current existence of usual signs of characteristic symptoms of HLB such as yellowing shoots, leaf mottling, and corky or enlarged veins on leaves. HLB-specific primer was employed in 16S rDNA polymerase chain reaction to detect the CLas gene in diseased trees. Increase in abundance of D. citri is mainly affected by the citrus flushing cycles and their life stages are completed on these flush shoots. Relative degree of aggregation index for D. citri adults increased during periods of cyclic production of new flush. HMO-treated plots produced a significantly lower percentage up to 11.43% of diseased trees against 42.20% in untreated control plots. HMO is effective against D. citri and recommended to be incorporated in the IPM program to prevent infection and reduce the spread of HLB

Dispersion pattern and sampling plan for Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae) in a citrus orchard

The ecology of the psyllid and its spatial distribution as the basis for the development of a reliable sampling plan are very important. The abundance and spatial distribution of Diaphorina citri (Hemiptera: Psyllidae) were studied in a commercial citrus orchard in southwestern Sarawak, Malaysia from April 2013 to December 2014. The spatial distribution of D. citri eggs, nymphs and adults were analysed using Taylor’s power law and Iwao’s patchiness regression. Taylor’s power law fitted the data better and produced higher values of R2 than Iwao’s regression model but did not work well with the egg populations. Based on both regression models, the field dispersion patterns of D. citri eggs, nymphs and adults were aggregated among flush shoots in individual trees as indicated by the regression slopes that were significantly >1. By homogeneity tests on both regression methods, the slopes of Taylor’s power law and Iwao’s regression model did not differ significantly for the D. citri population on honey tangerine for both years. The minimum number of flush shoots per tree required for estimates of D. citri densities varied from 2, 4 and 6 flush shoots for adults, nymphs and eggs, respectively, for the average density of each developmental stage obtained during our studies. Prediction suggested that a sampling plan consisting of 10 trees with the optimum number of six flush shoots per tree was required for reasonably accurate density estimation of the three life stages of D. citri acceptable enough for population studies and pest management program in citrus orchards

Incidence and spread of huanglongbing (HLB) or citrus greening disease in relation to the distribution and fluctuation of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) population in a citrus orchard in Sarawak, Malaysia

Diaphorina citri Kuwayama is a very prolific and most efficient vector for the fast huanglonbing (HLB) transmission which has destroyed nearly all citrus orchards with the economic deficit of RM 6.5 million or USD 1.6 million in Malaysia. D. citri coupled with HLB is therefore the greatest obstacle to the financial development of a sustainable and viable citrus industry in Malaysia. The study was aimed to evaluate the spread of HLB disease vectored by D. citri in relation to its spatial distribution and flight activity in response to flush cycles in a healthy orchard. Four types of yellow traps used to monitor for flight activity of this disease vector were evaluated monthly between June 2011 and December 2012. Both vector populations and HLB disease symptoms were monitored regularly between 2011 and 2014. A molecular diagnostic technique, Polymerase chain reaction (PCR) procedures was used to confirm the presence of the bacterium in diseased trees. D. citri adult populations expanded exponentially amid durations of cyclic production of new flush growths. The highest number of adult D. citri was captured by Rebel brown-yellow traps followed by Bamboo pole and yellow sticky traps with significant differences during the rainy months with monthly rainfall between 581-919 mm from October 2011 to March 2012 while higher catches were obtained by Bamboo pole traps during the dry months with monthly rainfall from 374-458 mm between May – September 2012. Yellow traps provided an indication of adult abundance and flight activity. It took about 21 months for D. citri population to spread all over the entire citrus garden. Rates of HLB transmission were related to high vector populations and spread was related to dispersing adults. Levels of HLB infected trees as determined by PCR increased progressively from 2.4% to 19.3% and 42.2% within four years after planting. The activity of infective D. citri is the key to HLB disease spread in a citrus orchard

Distribution patterns of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) eggs, nymphs and adults in a Malaysian citrus orchard

Spatial distribution of eggs, nymphs and adults of Diaphorina citri (Hemiptera: Psyllidae) was studied in a commercial orchard in SW Sarawak, Malaysia, using mean–variance test, the index of dispersion, and the negative binomial distribution. To further ascertain and confirm the distribution pattern in the population of the psyllid, dispersion indices (index of mean crowding, Lloyd’s index of patchiness, Taylor’s power law and Iwao’s patchiness regression) were calculated. Measurable tests showed that distribution of eggs and nymphs in naturally occurring psyllid populations was highly aggregated, resulting from initially aggregated migration of adults and a contagious dispersion of them on flushes as the population density increased of metals in the present study can be used as suitable reference for future studies