Biodegradation of polystyrene by three bacterial strains isolated from the gut of Superworms (Zophobas atratus larvae).

AIMS: To isolate polystyrene-degrading bacteria from the gut of superworms and investigate their ability to degrade polystyrene (PS). METHODS AND RESULTS: Three PS-degrading bacteria identified as Pseudomonas sp. EDB1, Bacillus sp. EDA4 and Brevibacterium sp. EDX were successfully isolated from the gut of superworms (Zophobas atratus Larvae) that ingest PS. Incubating PS with each strain for 30-day led to the formation of biofilm on the PS film. Scanning electron microscopy (SEM) revealed considerable damage (in terms of pits formation) on the surface of the PS films. FTIR analysis suggested the incorporation of carbonyl group into the carbon backbone of PS. Decreasing of WCA of microbial-treated PS film confirmed a chemical change from hydrophobicity to hydrophilicity on the PS surface. Based on these results, we conclude that all isolates had the ability to degrade PS. CONCLUSIONS: Brevibacterium sp. EDX (GenBank MZ32399) was isolated as the most efficient PS-degrading strain based on the most changing in both PS surface morphology (SEM and WCA analyses) and chemical modification (FTIR analysis) in its PS degradation process. SIGNIFICANCE AND IMPACT OF THE STUDY: This was the first study to describe the PS degradation by Brevibacterium sp. EDX, and thus provided for its development in the plastic remediation process.

Immunogenicity and potential protection of DNA vaccine of Leishmania martiniquensis against Leishmania infection in mice.

INTRODUCTION: In Thailand, Leishmania martiniquensis is the predominant species causing cutaneous and visceral leishmaniasis. Its incidence has been increasing among immunocompetent and immunocompromised hosts. We developed a prototype DNA vaccine using a partial consensus sequence of the cysteine protease B (cpb) gene derived from L. martiniquensis from Thai patients. METHODOLOGY: The laboratory inbred strain of albino BALB/c mice were immunized intramuscularly three times at 2-week intervals (weeks 0, 2, and 4) with cpb plasmid DNA (pcDNA_cpb) with or without the adjuvant, monoolein (pcDNA_cpb-MO). Mice were challenged at week 6 with L. martiniquensis promastigotes. Sera were analysed for IgG1, IgG2a, interferon gamma and interleukin 10 (IFN-γ and IL-10, respectively) levels at weeks 0, 4, and 9. Additionally, livers and spleens were also analysed for parasite burden using immunohistochemistry and real-time polymerase chain (qPCR) assays. RESULTS: Three weeks after promastigote challenge, vaccinated mice showed significantly increased levels of IgG2a and IFN-γ while IL-10 level was significantly reduced when compared with those in the control group (p < 0.01). Parasite burden in the livers and spleens of vaccinated mice significantly decreased. In addition, a significant increase in mature granuloma formation in the livers when compared with those of the control group (p < 0.05) was found, indicating increased T-helper cells (Th1)-induced inflammation and destruction of amastigotes. Monoolein produced a booster effect to enhance the mouse Th1 protective immunity. CONCLUSIONS: The prototype DNA vaccine could induce a Th1 immune response that conferred potential protection to the L. martiniquensis promastigote challenge in BALB/c mice.

Lack of Association between IL-10 Gene Promoter Polymorphisms and Susceptible to Tuberculosis in Thai Patients.

BACKGROUND: Cytokines play a major role in defense against Mycobacterium tuberculosis infection. Polymorphisms in the genes encoding various cytokines have been associated with tuberculosis susceptibility. Polymorphisms of the regulatoy cytokine gene, the interleukin (IL)-10 is associated with the risk of tuberculosis (TB) in different populations. However IL-10 gene polymorphism and susceptibility to TB in Thai is still unknown. OBJECTIVE: The purpose of this study was to evaluate whether the common IL-10 promoter gene polymorphisms are associated with TB in Thai population. MATERIAL AND METHOD: Forty-eight patients with newly diagnosed pulmonary tuberculosis were studied. DNA samples were extracted from leukocytes and used to investigate -1087A/G -819C/T -252C/A (rs1800896, rs1800871, rs1800872) in IL-10 gene using restriction fragment length polymorphism (PCR-RFLP) methods. RESULTS: In this study, the genotype and allele frequencies of IL-10-1087A/G, -819C/T -252C/A polymorphism did not significantly different between TB patients and healthy controls ((genotype: p = 0.38, p = 0.92,p = 1; allele: p = 0.57, p = 0.77, p = 0.89, respectively). CONCLUSION: The lack of association between common IL-10 promoter polymorphisms and TB susceptibility in this study may provide clue for better understanding of IL-10-1087A/G -819C/T -252C/A polymorphism and TB susceptibility in Thai population, which might facilitate the rationale design of vaccines. However further studies in large scales population are required for confirmation.

Low monocyte to neutrophil ratio in peripheral blood associated with disease complication in primary Plasmodium falciparum infection.

Immunity to malaria can be acquired but only after repeat exposures to polymorphic Plasmodium. However, the development of clinical outcomes during P. falciparum infection is not clearly understood. This study elucidated whether monocytes, neutrophils and pro/anti-inflammatory cytokines were associated with clinical outcomes in single infection and prior repeated malaria infections. Two hundred and seventy-nine patients with complicated and uncomplicated malaria were investigated. Peripheral blood IFN-gamma, TNF-alpha and IL-10 levels were measured by ELISA, and monocytes and neutrophils by an automated cell counter. On admission, in patients with uncomplicated malaria prior repeated infections, absolute neutrophil counts were positively and monocyte to neutrophil ratio negatively correlated significantly with parasitemia (r = 0.358, p = 0.000; r = -0.356, p = 0.000, respectively), while those with single infection absolute monocyte counts and monocyte to neutrophil ratio were significantly correlated negatively with IFN-gamma (r = -0.381, p = 0.001; r = -0.393, p = 0.000, respectively), and positively with TNF-alpha levels (r = 0.310, p = 0.007; r = 0.227, p = 0.017, respectively). In sharp contrast, in complicated malaria with single infection extremely high IFN-gamma and IL-10 levels but significantly low percent monocyte counts and monocyte to neutrophil ratio were seen. After 7 days of treatment, absolute monocyte counts and monocyte to neutrophil ratio were significantly increased, while absolute neutrophil counts significantly decreased (p = 0.000, 0.000, and 0.001, respectively), similarly after 28 days of treatment (p = 0.008, 0.000 and 0.000, respectively). These results suggest different functions of monocytes, neutrophils and pro/anti-inflammatory cytokines in complicated and uncomplicated malaria with single P. falciparum infection or prior repeated infections in the context of disease severity. Low monocyte to neutrophil ratio may be regarded as a risk factor in developing complication in primary malaria infection.

Haplotypes of IL12B promoter polymorphisms condition susceptibility to severe malaria and functional changes in cytokine levels in Thai adults.

Polymorphic variability in immune response genes, such as IL12B, encoding the IL-12p40 subunit is associated with susceptibility to severe malaria in African populations. Since the role of genetic variation in conditioning severe malaria in Thai adults is largely unexplored, the functional association between IL12B polymorphisms [i.e. IL12Bpro (rs17860508) and IL12B 3' UTR T/G (rs3212227)], severe malaria and cytokine production was examined in patients with Plasmodium falciparum infections (n = 355) recruited from malaria endemic areas along the Thai-Myanmar border in northwest Thailand. Circulating IL-12p40 (p = 0.049) and IFN-gamma (p = 0.051) were elevated in patients with severe malaria, while only IL-12p40 was significantly higher in severe malaria patients with hyperparasitaemia (p = 0.046). Carriage of the IL12Bpro1.1 genotype was associated with enhanced severity of malaria (OR, 2.34; 95% CI, 0.94-5.81; p = 0.066) and hyperparasitaemia (OR, 3.42; 95% CI, 1.17-9.87; p = 0.025) relative to the IL12Bpro2.2 genotype (wild type). Individuals with the IL12Bpro1.1 genotype also had the lowest IL-12p40 (p = 0.002) and the highest IFN-gamma (p = 0.004) levels. Construction of haplotypes revealed that carriage of the IL12Bpro-2/3' UTR-T haplotype was associated with protection against severe malaria (OR, 0.51; 95% CI, 0.29-0.90; p = 0.020) and reduced circulating IFN-gamma (p = 0.06). Thus, genotypic and haplotypic variation at IL12Bpro and IL12B 3' UTR in this population influences susceptibility to severe malaria and functional changes in circulating IL-12p40 and IFN-gamma levels. Results presented here suggest that protection against severe malaria in Thai adults is associated with genotypic variants that condition enhanced IL-12p40 and reduced IFN-gamma levels.

IL4 gene polymorphism and previous malaria experiences manipulate anti-Plasmodium falciparum antibody isotype profiles in complicated and uncomplicated malaria.

BACKGROUND: The IL4-590 gene polymorphism has been shown to be associated with elevated levels of anti-Plasmodium falciparum IgG antibodies and parasite intensity in the malaria protected Fulani of West Africa. This study aimed to investigate the possible impact of IL4-590C/T polymorphism on anti-P. falciparum IgG subclasses and IgE antibodies levels and the alteration of malaria severity in complicated and uncomplicated malaria patients with or without previous malaria experiences. METHODS: Anti-P.falciparum IgG subclasses and IgE antibodies in plasma of complicated and uncomplicated malaria patients with or without previous malaria experiences were analysed using ELISA. IL4-590 polymorphisms were genotyped using RFLP-PCR. Statistical analyses of the IgG subclass levels were done by Oneway ANOVA. Genotype differences were tested by Chi-squared test. RESULTS: The IL4-590T allele was significantly associated with anti-P. falciparum IgG3 antibody levels in patients with complicated (P = 0.031), but not with uncomplicated malaria (P = 0.622). Complicated malaria patients with previous malaria experiences carrying IL4-590TT genotype had significantly lower levels of anti-P. falciparum IgG3 (P = 0.0156), while uncomplicated malaria patients with previous malaria experiences carrying the same genotype had significantly higher levels (P = 0.0206) compared to their IL4-590 counterparts. The different anti-P. falciparum IgG1 and IgG3 levels among IL4 genotypes were observed. Complicated malaria patients with previous malaria experiences tended to have lower IgG3 levels in individuals carrying TT when compared to CT genotypes (P = 0.075). In contrast, complicated malaria patients without previous malaria experiences carrying CC genotype had significantly higher anti-P. falciparum IgG1 than those carrying either CT or TT genotypes (P = 0.004, P = 0.002, respectively). CONCLUSION: The results suggest that IL4-590C or T alleles participated differently in the regulation of anti-malarial antibody isotype profiles in primary and secondary malaria infection and, therefore, could play an important role in alteration of malaria severity.

Relative levels of IL4 and IFN-gamma in complicated malaria: association with IL4 polymorphism and peripheral parasitemia.

Functional IL4-590 C/T polymorphisms and the relative amounts of IL4 and IFN-gamma were investigated in relation to severity of malaria in 110 and 169 Thai patients with complicated and uncomplicated malaria, respectively. The plasma IL4 and IFN-gamma levels were determined by ELISA and the IL4-590 C/T polymorphisms were genotyped. The IFN-gamma levels were significantly elevated in patients with complicated malaria in the initial stage of the disease before treatment compared to the levels found with uncomplicated malaria (231pg/ml versus 150pg/ml, p=0.0029), while the IL4 levels were significantly elevated 7 days after treatment (167pg/ml versus 81pg/ml, p=0.0003). Our study did not reveal any association between the IL4-590 C/T transition and the severity of malaria. However, a significant difference in the IL4 to IFN-gamma ratio between patients with complicated and uncomplicated malaria was observed only in patients with IL4-590 T allele homozygosity (geometric mean: 0.321 versus 0.613, p=0.0087 for TT allele). A significant inverse correlation between IL4 to IFN-gamma ratio and peripheral parasitemia was observed only in complicated malaria patients carrying TT genotype (r=-0.283, p=0.046). These results suggest that the IL4-590 C/T polymorphism may play a role in the balance between IL4 and IFN-gamma, as well as in the control of parasitemia, which in turn may alter the severity of malaria.