RESUMEN
Plant growth promoting rhizobacteria (PGPR) are strains of naturally occurring soil bacteria that live in close vicinity to the plant's rhizosphere region which possess the capability to augment host growth. This study was conducted to isolate and identify potential PGPR isolates indigenous to Metroxylon sagu, Rottb. rhizosphere. These potential isolates were characterised based on their beneficial plant growth promoting (PGP) properties and identified by molecular analysis via 16S rDNA sequencing. A total of 18 isolates were successfully isolated, out of which five isolates were tested, and designated as (S1A, S2B, S3A, S3C and S42). Among the five isolates, two isolates (S2B and S3C) were found to produce high levels of indole-3-acetic acid (2.96 µg/mL and 10.31 µg/mL), able to fix nitrogen and show significant activity in phosphate solubilisation. The analysis of their sequences via National Center for Biotechnology Information (NCBI) suggested their close identity towards Lysinibacillus sphaericus and Bacillus thuringiensis. It can be concluded that the isolated PGPR possesses beneficial PGP attributes. It can be implied that the isolated PGPR are potential to be used as inoculant biofertilisers, beneficial for Metroxylon sagu, Rottb. growth. Hence, further studies need to be done to evaluate the effectiveness of the beneficial microbes towards sago seedlings growth, under pot experiment.
Rizobakteria penggalak pertumbuhan tumbuhan adalah sejenis bakteria tanah yang hidup berdekatan rizosfera tumbuhan dan mempunyai impak berfaedah ke atas pertumbuhan tanaman. Kajian ini telah dijalankan untuk melakukan pengasingan dan pengecaman PGPR, daripada rizosfera Metroxylon sagu, Rottb. Bakteria endofit diasing berdasarkan ciri-ciri penggalak tumbuhan yang kemudiannya dipilih untuk pengenalpastian secara biologi molekul melalui 16S rDNA sequencing. Sebanyak 18 bakteria berjaya diasingkan, dan lima jenis bakteria dipilih berdasarkan ciri-ciri penggalak tumbuhan dan dilabelkan sebagai S1A, S2B, S3A, S3C dan S42. Di antara kelima-lima bakteria tersebut, dua bakteria (S2B dan S3C) dijumpai mempunyai kemampuan untuk menghasilkan kadar indole-3-acetic acid (IAA) yang tinggi (2.96 µg/mL dan 10.31 µg/mL), mempunyai kemampuan mengikat gas nitrogen serta menunjukkan aktiviti yang memberangsangkan dalam mengurai fosfat. Hasil analisis biologi molekul melalui NCBI menunjukkan identiti terdekat kedua-dua bakteria tersebut cenderung kepada Lysinibacillus sphaericus dan Bacillus thuringiensis. Melalui hasil penyelidikan ini, dapat dirumuskan bahawa PGPR yang telah diasingkan daripada rizosfera Metroxylon sagu, Rottb., mempunyai ciri-ciri penggalak tumbuhan dan berpotensi untuk digunakan sebagai inokulan biobaja, berfaedah kepada pertumbuhan Metroxylon sagu, Rottb. Maka, kajian selanjutnya perlu dilakukan untuk menilai keberkesanan mikrob ke atas pertumbuhan benih sagu, melalui eskperimen dalam pasu.
RESUMEN
Introduction: Staphylococcus aureus is a leading cause of cutaneous bacterial infection involving community. Methods: In this study, a total of 42 swab samples were collected from the surface of various fitness equipment such as back machines, exercise mats, dip stations, dumbbells, and treadmills. Identification of the bacterial isolates was conducted using biochemical tests and further analysed molecularly using the PCR method targeting nuc gene (270 bp). The nuc gene encodes for the thermonuclease enzyme, a virulent factor of S. aureus. Results: The findings showed 31 out of 42 swab samples (73.81%) were positive with S. aureus. Conclusion: This study showed that gymnasium equipment is a potential reservoir for S. aureus and might play an important role in transmitting the pathogen to humans. Objective: This study was undertaken to assess the presence of S. aureus on the surface of fitness equipment from selected gymnasiums in Kuching and Kota Samarahan, Sarawak (Malaysia).
Asunto(s)
Microbiología Ambiental , Contaminación de Equipos/estadística & datos numéricos , Equipo Deportivo/estadística & datos numéricos , Staphylococcus aureus/aislamiento & purificación , Proteínas Bacterianas/análisis , Malasia , Nucleasa Microcócica/análisis , Reacción en Cadena de la PolimerasaRESUMEN
This study aimed to identify Listeria spp. and L. monocytogenes, characterize the isolates, and determine the antibiotic resistance profiles of the isolates Listeria spp. and L. monocytogenes in fresh produce, fertilizer, and environmental samples from vegetable farms (organic and conventional farms). A total of 386 samples (vegetables, soil, water, and fertilizer with manure) were examined. The identification of bacterial isolates was performed using PCR and characterized using ERIC-PCR and BOX-PCR. The discriminating power of the typing method was analyzed using Simpson's Index of Diversity. Thirty-four (n=34) Listeria isolates were subjected to antimicrobial susceptibility test using the disc-diffusion technique. The PCR analysis revealed that Listeria spp. were present in 7.51% (29/386) of all the samples (vegetable, soil, fertilizer, and water). None of the samples examined were positive for the presence of L. monocytogenes. Percentages of 100% (15/15) and 73.30% (11/15) of the Listeria spp. isolated from vegetables, fertilizer, and soil from organic farm B had indistinguishable DNA fingerprints by using ERIC-PCR and BOX-PCR, respectively. Listeria spp. isolated from 86 samples of vegetable, fertilizer, and environment of organic farm A and conventional farm C had distinct DNA fingerprints. Simpson's Index of Diversity, D, of ERIC-PCR and BOX-PCR is 0.604 and 0.888, respectively. Antibiotic susceptibility test revealed that most of the Listeria spp. in this study were found to be resistant to ampicillin, rifampin, penicillin G, tetracycline, clindamycin, cephalothin, and ceftriaxone. The isolates had MAR index ranging between 0.31 and 0.85. In conclusion, hygienic measures at farm level are crucial to the reduction of Listeria transmission along the food chain.
Asunto(s)
Farmacorresistencia Microbiana , Microbiología de Alimentos , Heterogeneidad Genética , Listeria monocytogenes , Antibacterianos , Granjas , Variación Genética , Listeria/genética , Listeria/aislamiento & purificación , Listeria monocytogenes/genética , Listeria monocytogenes/aislamiento & purificación , Reacción en Cadena de la Polimerasa , PrevalenciaRESUMEN
In the last decades, leptospirosis had gained public health concern due to morbidity and mortality rates caused by pathogenic Leptospira. The need for rapid and robust molecular typing methods to differentiate this zoonotic pathogen is of utmost importance. Various studies had been conducted to determine the genetic relatedness of Leptospira isolates using molecular typing methods. In this study, 29 pathogenic Leptospira isolates from rat, soil, and water samples in Sarawak, Malaysia, were characterized using BOX-PCR and ERIC-PCR. The effectiveness of these two methods with regard to the ease of interpretation, reproducibility, typeability, and discriminatory power was also being evaluated. Using BOX-PCR, six clusters and 3 single isolates were defined at a genetic distance percentage of 11.2%. ERIC-PCR clustered the isolates into 6 clusters and 2 single isolates at a genetic distance percentage of 6.8%. Both BOX-PCR and ERIC-PCR produced comparable results though the discriminatory index for ERIC-PCR (0.826) was higher than that for BOX-PCR (0.809). From the constructed dendrogram, it could be summarized that the isolates in this study were highly heterogeneous and genetically diverse. The findings from this study indicated that there is no genetic relatedness among the pathogenic Leptospira isolates in relation to the locality, source, and identity, with some exceptions. Out of the 29 pathogenic Leptospira isolates studied, BOX-PCR and ERIC-PCR successfully discriminated 4 isolates (2 isolates each) into the same cluster in relation to sample sources, as well as 2 isolates into the same cluster in association with the sample locality. Future studies shall incorporate the use of other molecular typing methods to make a more thorough comparison on the genetic relatedness of pathogenic Leptospira.
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ADN Bacteriano/genética , Leptospira/aislamiento & purificación , Leptospirosis/diagnóstico , Tipificación Molecular/métodos , Reacción en Cadena de la Polimerasa/métodos , Animales , Evolución Molecular , Humanos , Leptospira/clasificación , Leptospira/genética , Hígado/microbiología , Malasia , Filogenia , Ratas , Reproducibilidad de los Resultados , Microbiología del Suelo , Microbiología del Agua , Zoonosis/diagnóstico , Zoonosis/microbiologíaRESUMEN
Cryptosporidiosis and cyclosporiasis are caused by waterborne coccidian protozoan parasites of the genera Cryptosporidium and Cyclospora, respectively. This study was conducted to detect Cryptosporidium and Cyclospora oocysts from environmental water abstracted by drinking water treatment plants and recreational activities in Sarawak, Malaysia. Water samples (12 each) were collected from Sungai Sarawak Kanan in Bau and Sungai Sarawak Kiri in Batu Kitang, respectively. In addition, 6 water samples each were collected from Ranchan Recreational Park and UNIMAS Lake at Universiti Malaysia Sarawak, Kota Samarahan, respectively. Water physicochemical parameters were also recorded. All samples were concentrated by the iron sulfate flocculation method followed by the sucrose floatation technique. Cryptosporidium and Cyclospora were detected by modified Ziehl-Neelsen technique. Correlation of the parasites distribution with water physicochemical parameters was analysed using bivariate Pearson correlation. Based on the 24 total samples of environmental water abstracted by drinking water treatment plants, all the samples (24/24; 100%) were positive with Cryptosporidium, and only 2 samples (2/24; 8.33%) were positive with Cyclospora. Based on the 12 total samples of water for recreational activities, 4 samples (4/12; 33%) were positive with Cryptosporidium, while 2 samples (2/12; 17%) were positive with Cyclospora. Cryptosporidium oocysts were negatively correlated with dissolved oxygen (DO).
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Cryptosporidium/aislamiento & purificación , Cyclospora/aislamiento & purificación , Agua Potable/parasitología , Oocistos/aislamiento & purificación , Animales , Criptosporidiosis/parasitología , Criptosporidiosis/transmisión , Cryptosporidium/patogenicidad , Cyclospora/patogenicidad , Heces/parasitología , Humanos , Malasia , Oocistos/patogenicidad , Purificación del AguaRESUMEN
Various prevalence studies on Leptospira in animals and humans, as well as environmental samples, had been conducted worldwide, including Malaysia. However, limited studies have been documented on the presence of pathogenic, intermediate, and saprophytic Leptospira in selected animals and environments. This study was therefore conducted to detect Leptospira spp. in rats, soil, and water from urban areas of Sarawak using the polymerase chain reaction (PCR) method. A total of 107 rats, 292 soil samples, and 324 water samples were collected from April 2014 to February 2015. Pathogenic Leptospira was present in 5.6% (6/107) of rats, 11.6% (34/292) of soil samples, and 1.9% (6/324) of water samples. Intermediate Leptospira was present in 2.7% (8/292) of soil samples and 1.9% (6/324) of water samples. Saprophytic Leptospira was present in 10.3% (11/107) of rats, 1.4% (4/292) of soil samples, and 0.3% (1/324) of water samples. From this study, 76 Leptospira spp. were isolated. Based on DNA sequencing, the dominant Leptospira spp. circulating in urban areas of Sarawak are pathogenic Leptospira noguchii, intermediate Leptospira wolffii serovar Khorat, and saprophytic Leptospira meyeri, respectively. Overall, this study provided important surveillance data on the prevalence of Leptospira spp. from rats and the environment, with dominant local serovars in urban areas of Sarawak.
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Bacterial resistance to various antimicrobial agents is common in area with high usage of antibiotics. In this study, the data on antimicrobial susceptibility patterns of Vibrio cholerae O1 from patients during an outbreak period was found to be high but variable rates of multidrug resistance. Thirty-two of 33 V. cholerae isolates harboured the tcp, ctx, zot and ace genes, suggesting their possible roles in the outbreak cases. We analyzed the molecular diversity of a total of 33 strains of V. cholerae O1 isolated from 33 patients between November 1997 and April 1998 using random amplified polymorphic DNA (RAPD) analysis. The 30 typable isolates could be separated into four major clusters containing 5, 17, 2 and 6 isolates, respectively. However, no particular RAPD pattern was predictive of a particular pattern of antibiotic susceptibility. The findings of this study showed that multiple clones seemed to be responsible for cases in the outbreaks in the study area.