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Molecular characterization and phylogenetic analysis of avian influenza H3N8 virus isolated from imported waterfowl in Malaysia.

Wild aquatic birds are natural reservoirs of influenza A viruses and H3 subtype is one of the most prevalent subtypes in waterfowl. Two H3N8 viruses of low pathogenic avian influenza (LPAI) were isolated via egg inoculation technique from the fecal swab specimens from imported barnacle goose and paradise shelduck in Veterinary Research Institute Ipoh, Malaysia. The full length of eight gene segments of the two viruses were amplified and sequenced with specific primers. The sequences were molecularly characterized, and the sequence identity were assessed with other published sequences. The two viruses are identical and they possess the same amino acid sequences for all the eight gene segments. The viruses were highly similar to the H3 virus from Netherlands and N8 virus from Belgium respectively. Phylogenetic analysis revealed that all the eight gene segments were grouped in the Eurasian lineage, and genetic reassortment may occur between the internal genes of the H3 viruses and other AI subtypes. Though four amino acid substitutions were identified in the hemagglutinin gene, the viruses retained most of the avian-type receptor binding preference. Few amino acid substitutions were observed in all internal genes. Most of the neuraminidase inhibitors and adamantine resistance related mutation were not seen in the viruses. The replicative capacity, cross species transmissibility, and potential zoonotic risk of the viruses are worth further investigation. As H3 virus poses potential threats to both human and animals, and with the increase in the international trade of birds; strict quarantine practice at the entry point and good laboratory diagnostic capabilities is crucial to prevent the introduction of new AI virus into our country.

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Prevalence and risk factors for infection with Entamoeba histolytica/dispar/ moshkovskii complex in people living in the slightest and outermost islands of Indonesia.

Entamoeba histolytica (E. histolytica), the causative agent of amoebiasis, is still a global public health problem that cannot be controlled, especially in tropical and subtropical countries. This study was conducted to obtain information about the incidence of Entamoeba histolytica/dispar/ moshkovskii complex infection and the factors that influence it. The prevalence of infection with the Entamoeba histolytica/dispar/moshkovskii complex and the factors that influence it in people living on the smallest and outermost island of Indonesia, Sabang Island, Aceh Province. This study involved 335 respondents aged >= 10 years. Respondents were selected by non-probability sampling technique. Interviews and observations were conducted to identify risk factors. The Entamoeba histolytica/dispar/ moshkovskii complex was identified by direct examination, concentration, and Whitley's trichrome staining techniques. A Chi-Square test was performed to analyze the correlation of risk factors with the incidence of infection. The prevalence of infection with the Entamoeba histolytica/dispar/ moshkovskii complex in the people of Sabang Island was 26.6% (89/335). Source and adequacy of clean water correlated with the incidence of Entamoeba histolytica/dispar/moshkovskii complex infection. Demographic variables are not correlated with the incidence of infection. However, the group of women aged > 61 years, unemployed, unmarried, and earning less than the regional minimum wage tend to be more likely to be found with Entamoeba histolytica/dispar/moshkovskii complex infections. Thus it can be concluded that the prevalence of infection with the Entamoeba histolytica/dispar/moshkovskii complex on Sabang Island is in the high category. The prevalence of E. histolytica as the causative agent of amoebiasis cannot be explained with certainty because the two identical non-pathogenic Entamoeba species cannot be distinguished by microscopic identification. Sources and adequacy of clean water correlate with the incidence of Entamoeba histolytica/dispar/moshkovskii complex infection in the people of Sabang Island.

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Antimicrobial activity of essential oils of Curcuma longa and Syzygium aromaticum against multiple drug-resistant pathogenic bacteria.

The present study was conducted to investigate the antimicrobial potential of essential oils of Curcuma longa and Syzygium aromaticum against multidrug-resistant pathogenic bacteria. Four identified bacterial isolates including Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii were selected and their antibiotic sensitivity was checked by disc diffusion assay. C. longa and S. aromaticum were subjected to steam distillation to obtain their essential oils. The crude essential oils were fractioned by employing column chromatography. Crude essential oils and their fractions were evaluated for their antibacterial activity by agar well diffusion assay and minimum inhibitory concentrations were calculated. All the selected bacterial isolates showed resistance to three or more than three antibiotic groups and were declared as multidrugresistant (MDRs). Crude essential oils of C. longa and S. aromaticum exhibited antimicrobial activity against all selected isolates but S. aromaticum activity was better than the C. longa with a maximum 19.3±1.50 mm zone of inhibition against A. baumannii at 1.04 µL/mL MIC. GC/MS analysis revealed the abundance of components including eugenol, eugenyl acetate, b- caryophyllene, and a- Humulene in both crude oil and fractions of S. aromaticum. While the main components of C. longa essential oil were Ar-tumerone, a-tumerone, b- Tumerone, I-Phellandrene, a-zingibirene, b- sesquiphellandrene, and p- Cymene. This study highlights that plant-based essential oils could be a promising alternative to antibiotics for which pathogens have developed resistance. C. longa and S. aromaticum carry compounds that have antimicrobial potential against multiple drug-resistant bacteria including MRSA. E. coli, K. pneumoniae and A. baumannii.

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Molecular detection of filarial nematode from Culicoides biting midges (Diptera: Ceratopogonidae) in northeastern Thailand.

Culicoides Latreille biting midges are important blood feeding insects. Many species are pests and vectors of the disease causing agents including viruses, protozoa and filarial nematodes which can be transmitted to humans and other animals. However, knowledge of the role of Culicoides as vectors of filarial nematodes is limited, particular in Thailand, where at least 100 species of the genus Culicoides have been reported. In this study, a molecular approach using the 12S rRNA gene sequence was used to detecting the filarial nematode in four common biting midge species, C. actoni Smith, C. oxystoma Kieffer, C. peregrinus Kieffer and C. mahasarakhamense Pramual, Jomkumsing, Piraonapicha & Jumpato in animal shelters from northeastern Thailand. A total of 1,721 specimens were used for molecular screening. An unidentified Onchocercidae sp. was detected in a specimen of C. mahasarakhamense collected from Maha Sarakham province. This filarial species shows 93% sequence similarity with an unidentified Onchocercidae sp. isolated from Culex mosquitoes. Phylogenetic analyses revealed that Onchocercidae sp. from C. mahasarakhamense formed a clade with strong bootstrap support (100%) with filarial species detected in birds. Thus, it is very likely that the Onchocercidae sp. found in this study employes birds as vertebrate hosts which agrees with feeding behavior of C. mahasarakhamense which is known to feed on chicken. Further study is requiring to examine whether this biting midge species is a competent vector of this Onchocercidae sp.

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Transferable mechanisms of quinolone resistance are more frequent among enterotoxigenic Escherichia coli isolates displaying low-level quinolone resistance.

This study analysed the mechanisms of quinolone resistance among enterotoxigenic Escherichia coli (ETEC) in a periurban area of Lima, Peru. The susceptibility to nalidixic acid and ciprofloxacin, the role of Phe-Arg-b-Naphtylamyde inhibitable-(PAbN) efflux pumps, the presence of mutations in gyrA and parC as well as the presence of aac(6')Ib-cr, qepA, qnrA, qnrB, qnrC, qnrD, qnrVC and oqxAB were determined in 31 ETEC from previous case/control studies of children's diarrhoea. Discordances between disk diffusion, with all isolates showing intermediate or fully resistance to nalidixic acid, and minimal inhibitory concentration (MIC), with 7 isolates being below considered resistance breakpoint, were observed. Twenty-one isolates possessed gyrA mutations (19 S83L, 2 S83A). AAC(6') Ib-cr, QnrS, QnrB and QepA were found in 7, 6, 2 and 1 isolates respectively, with 3 isolates presenting 2 transferable mechanisms of quinolone resistance (TMQR) concomitantly. TMQR were more frequent among isolates with MIC to nalidixic acid ranging from 2 to 16 mg/L (p=0.03), while gyrA mutations were more frequent among isolates with nalidixic acid MIC >= 128 mg/L (p=0.0002). In summary, the mechanisms of quinolone resistance present in ETEC isolates in Peru have been described. Differences in the prevalence of underlying mechanisms associated with final MIC levels were observed. The results suggest two different evolutive strategies to survive in the presence of quinolones related to specific bacterial genetic background.

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Insecticidal activity and physiopathological effects of Cotula cinerea crude extract against Culex pipiens.

The development of new alternatives strategies to synthetic insecticides aimed at reducing pest populations by developing pesticides based on plant extracts without negative effects in non target organisms and environment. The present study was undertaken in order to assess the insecticidal activity of the crude methanolic extract of the Algerian Asteraceae Cotula cinerea, against the larval and the pupal stage of Culex pipiens (Diptera: Culicidae). It is also to determine the chemical composition of the used extract, and to understand the mechanism of toxic action of the tested extract. Based on the preliminary tests, five concentrations of the crude methanolic extract of C. cinerea (0.62, 1.25, 2.50, 3.75, and 5 mg/mL) were tested for their insecticidal activity according to the protocol recommended by the World Health Organization. The chemical profile of the extract was also obtained by high performance liquid chromatography (HPLC). Histopathological effects and inhibition of acetylcholinesterase activity in treated mosquitoes with LC90 were examined to elucidate the mechanism of the toxic effect of the tested extract (48 h post treatment). Eight compounds have been identified by HPLC. That includes four flavonoids (rutin, quercetin, myrcetin and cathechin), three phenolic acids (benzoic acid, vanillic acid, p-coumaric acid) and one alkaloid (berberine). C. cinerea methanolic extract showed good larvicidal and pupicidal activities with LC50 and LC90 values of 1.10 and 4.37 mg/mL respectively against pupae, 24h post treatment and 1.26, 2.35 mg/mL respectively against the fourth instar larvae. Data of enzymatic assay performed on LC50 and LC90 pupae and larvae revealed prominent neurotoxic effects. C. cinerea extract reduced the activity of acetylcholinesterase (AChE) enzyme in a concentration dependent manner. Obtained inhibition percentages, 48 h after treatment, were 35.11 ± 7.44 and 51.83 ± 4.04% for pupal stage and 30.98 ± 2.97 % and 48.77 ± 4.72% for the fourth instar larvae for LC50 and LC90 values respectively. Treated larvae and pupae showed also histopathological damages in the pupal cuticle and larval midgut. The results of this study showed that C. cinerea crude methanolic extract could be considered as an eco-friendly alternative for mosquito control.

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Post-mortem pulmonary tuberculosis: comparison of available diagnostic methods.

Tuberculosis (TB) caused by Mycobacterium tuberculosis remains a serious public health threat with the World Health Organisation (WHO) reporting 5.8 million cases and 1.3 million deaths in the year 2020 due to TB. TB can be diagnosed by imaging, histopathological and bacteriological methods with culture remaining the gold standard. This study was performed to look at the sensitivity and specificity of post-mortem computed tomography (PMCT) imaging when compared to culture in diagnosing pulmonary tuberculosis. This was a retrospective comparative study looking at post mortem cases where lung tissue samples sent for TB culture at Hospital Kuala Lumpur were compared against PMCT imaging. Exclusion criteria included contaminated samples, decomposed cases, immunocompromised subjects and those below 18 years of age. Subjects included 80 medico-legal autopsy cases at the National Institute of Forensic Medicine, Hospital Kuala Lumpur, Malaysia who had whole body PMCT done in accordance with the Institute's protocol and tissue samples sent for bacteriology culture for tuberculosis. PMCT findings were positively associated with acid-fast organisms in 23.5 out of 33 cases (71.2%). Our study also showed that PMCT had a sensitivity of 71.3% and specificity of 54.3% (95% CI: 39.5-68.4) in diagnosing TB based on the protocol set in this study. This study showed that there was relatively good agreement between radiological PMCT findings and bacterial culture, suggesting that radiological examination is a relatively reliable tool for preliminary screening and possible diagnosis of TB prior to a postmortem examination which would be beneficial in reducing the risk of transmission of TB to health workers during autopsy.

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