Acanthamoeba castellanii of the T4 genotype is a potential environmental host for Enterobacter aerogenes and Aeromonas hydrophila

Background: Acanthamoeba can interact with a wide range of microorganisms such as viruses, algae, yeasts, protists and bacteria including Legionella pneumophila, Pseudomonas aeruginosa, Vibrio cholerae, Helicobacter pylori, Listeria monocytogenes, Mycobacterium spp., and Escherichia coli. In this capacity, Acanthamoeba has been suggested as a vector in the transmission of bacterial pathogens to the susceptible hosts.Methods: Here, we used a keratitis isolate of A. castellanii of the T4 genotype and studied its interactions with two bacterial genera which have not been tested before, Enterobacter aerogenes, and Aeromonas hydrophila, as well as E. coli. Assays were performed to determine bacterial association with and invasion of A. castellanii. Additionally, bacterial survival intracellular of A. castellanii trophozoites as well as cysts was determined.Results: All three bacterial isolates tested, associated, invaded, and survived inside A. castellanii trophozoites as well as A. castellanii cysts. However, E. aerogenes and E. coli exhibited significantly reduced association with and invasion of A. castellanii as compared with A. hydrophila (P \u3c 0.01 using paired T-test, one tail distribution). In the long term survival assays, all three bacterial isolates tested remained viable inside A. castellanii trophozoites, while amoeba remained intact; however A. hydrophila exhibited higher survival inside amoebae (14.54±3.3 bacteria:amoeba ratio) compared with E. aerogenes (3.96±0.7 bacteria:amoeba ratio) and E. coli (5.85±1.1 bacteria:amoeba ratio). A. hydrophila, E. coli, and E. aerogenes remained viable during the encystment process and exhibited higher levels of recovery from mature cysts (14.13±0.89 A. hydrophila:amoeba ratio, 10.13±1.17 E. aerogenes:amoeba ratio, and 11.95±0.7 E. coli:amoeba ratio).Conclusions: A. hydrophila and E. aerogenes also joined the ranks of other bacteria that could benefit from A. castellanii. Because cysts can be airborne, these findings suggest that Acanthamoeba is a potential vector in the transmission of A. hydrophila and E. aerogenes to susceptible hosts

Interactions of neuropathogenic Escherichia coli K1 (RS218) and its derivatives lacking genomic islands with phagocytic Acanthamoeba castellanii and nonphagocytic brain endothelial cells

Here we determined the role of various genomic islands in E. coli K1 interactions with phagocytic A. castellanii and nonphagocytic brain microvascular endothelial cells. The findings revealed that the genomic islands deletion mutants of RS218 related to toxins (peptide toxin, alpha -hemolysin), adhesins (P fimbriae, F17-like fimbriae, nonfimbrial adhesins, Hek, and hemagglutinin), protein secretion system (T1SS for hemolysin), invasins (IbeA, CNF1), metabolism (D-serine catabolism, dihydroxyacetone, glycerol, and glyoxylate metabolism) showed reduced interactions with both A. castellanii and brain microvascular endothelial cells. Interestingly, the deletion of RS218-derived genomic island 21 containing adhesins (P fimbriae, F17-like fimbriae, nonfimbrial adhesins, Hek, and hemagglutinin), protein secretion system (T1SS for hemolysin), invasins (CNF1), metabolism (D-serine catabolism) abolished E. coli K1-mediated HBMEC cytotoxicity in a CNF1-independent manner. Therefore, the characterization of these genomic islands should reveal mechanisms of evolutionary gain for E. coli K1 pathogenicity

Heavy Metals in Terapon puta

This study was carried out to investigate the accumulation of Fe, Mn, Cd, Pb, and Ni in Terapon puta from Karachi Fish Harbor, Pakistan. There were no significant differences in the concentration of the metals except Mn in T. puta, which is obtained from the different seasons. The highest metal concentration is Fe followed by Mn. Cd, Pb, and Ni were measured relatively lower concentrations. The mean (± SD) Fe, Mn, Cd, Ni, and Pb levels in the muscles tissues of T. puta were 25.5±13.71, 6.07±3.58, 0.47±0.29, 0.46±0.27, and 0.43±0.25 mg/kg dry wt., respectively, whereas the mean (± SD) Fe, Mn, Cd, Ni, and Pb levels in the liver tissues of T. puta were 562±105, 18.62±11.86, 1.06±0.47, 1.20±0.53, and 1.01±0.50 mg/kg dry wt., respectively. Cd and Pb levels exceeded the Commission Regulation of European Union maximum limit of 0.05 mg/kg and 0.30 mg/kg, respectively. However, the results of Estimated Weekly Intake and Estimated Daily Intake indicate that the heavy metal levels in the samples are generally within respective recommended guidelines. Thus, it would appear from this study that the heavy metal levels in T. puta from Karachi coasts are low enough not to present a health hazard if the fish are consumed, although due attention should be paid to the maximum acceptable daily intake per kilogram body weight

Higher DNA methylation of ABO gene promoter is associated with acute myocardial infarction in a hospital-based population in Karachi

Objective: To find out if there is any relationship of methylation status of ABO gene promoter with the risk of acute myocardial infarction (AMI) in a hospital-based Pakistani population in Karachi, Pakistan.Methods: A case control study comprising of 39 adult AMI patients (both males and females; age range 30-70 years) and 39 normal healthy controls (both males and females and similar age range) nested in a large study (to see the relationship of ABO genotypes with AMI) was designed to investigate the methylation status of ABO gene promoter and its association with AMI. The study was carried out at the Aga Khan University, Karachi during July 2018 to June 2019. DNA isolated from samples of AMI patients and normal healthy controls were converted into bisulphite DNA using a kit method. Methylation specific polymerase chain reaction was carried out to determine the methylation status of ABO gene promoter in both cases and controls. Logistic regression was used to find out any association between increased methylation status of ABO gene promoter and risk of AMI.Results: A significantly higher percentage of DNA methylation of the ABO gene promoter was observed in AMI patients as compared to normal healthy controls (82.1% vs. 35.9%; p value \u3c0.001). This higher methylation status of ABO gene promoter was associated with AMI and the odds of AMI in this population were more than 6-fold in subjects with methylated gene promoter compared to those with unmethylated gene promoter after adjusting with age and waist circumference [AOR (95% CI) = 6.27 (1.76-22.3); p value = 0.005].Conclusion: The ABO gene promoter\u27s hypermethylation appears to be increasing the risk of AMI in a hospital-based Pakistani population in Karachi, Pakistan

Anti-acanthamoebic properties of natural and marketed honey in Pakistan

To determine anti-Acanthamoebic activity of natural and marketed honey samples. Natural honey samples were collected directly from the bee hive and marketed honey samples were purchased from the local market in Karachi, Pakistan. Both honey samples were tested for their flavonoid content (quercetin equivalent per g of the extract) and phenolic content (gallic acid equivalent per g). Furthermore, their antioxidant activity was determined by measuring 2,2-diphenyl-1-picrylhydrazyl. Using amoebistatic and amoebicidal assays, the effects of honey samples were tested against growth and viability of Acanthamoeba parasites. Natural honey exhibited potent amoebistatic and amoebicidal effects, in a concentration-dependent manner. Honey-treated A. castellanii showed loss of acanthopodia, following which amoebae detached, rounded up, reduced in size, decreased in cytoplasmic mass and they were observed floating in the culture medium. Importantly, honey-treated amoebae did not revive when inoculated in fresh growth medium, however glycerol-treated amoebae exhibited viable trophozoite and active growth. In contrast, marketed honey samples varied in their efficacy against A. castellanii. The proportion of flavonoid, as determined by quercetin measurements and the proportion of phenolic, as determined by gallic acid measurements was higher in natural honey compared with marketed honey. Similarly, the antioxidant activity, as determined by 2,2-diphenyl-1-picrylhydrazyl scavenging activity was higher in natural honey versus marketed honey. This study shows that natural honey has anti-Acanthamoebic properties and possesses higher flavonoid, phenolic and antioxidant properties compared with the marketed honey. These findings are of concern to the public, health officials, and to the manufacturers regarding production of honey for medical applications

Effects of seasons on condition factor and weight - length relationship in Dussumier's halfbeak, Hyporhamphus dussumieri (Valenciennes, 1847), (Actinopterygii: Beloniformes: Hemiramphidae) from Karachi coast in the Arabian Sea

A total of (n=114) H. dussumieri were collected during monsoon (August and September), post monsoon (October and November) seasons in 2011. Mean total length of females (t test: P = 2.5663E-12) and males (t test: P = 1.4766E-08) between two seasons were significantly different. Similarly, mean total length (t test: P = 9.8887E-20) and Size-frequency distribution (Kolmogorov-Smirnov two sample test: d = 0.82716, P = 3.41312E-15) were significantly different between monsoon and postmonsoon for combined sexes. The slope (b) of WLRs regression lines for monsoon except for male were significantly different from the isometric growth curve slope (b = 3). Therefore, the slope of WLRs regression lines for postmonsoon by combined sex and both female and male were significantly lower than the isometric growth curve slope (b = 3) suggesting negative allomnetric growth in post-monsoon season

Fecundity of three species of Penaeid shrimps, Penaeus monodon (Fabricius, 1798), Penaeus indicus (H. Milne-Edwards, 1837) and Penaeus japonicus (Bate, 1888) of Karachi coast, Pakistan

In order to define the period of maturity of penaeid shrimps at least three indices (fecundity, size structure and density of mature females) are required. During the present study the relationships between fecundity and total length, carapace length, ovary length, body weight and ovary weight of three species of Penaeid shrimps, Penaeus (Fenneropenaeus) indicus, Penaeus (Marsupenaeus) japonicus and Penaeus (Penaeus) monodon were found out. Samples of shrimps were collected from fish market, identified to the species level, morphometric measurements of each individual were recorded and the fecundity of each developed shrimp was estimated. The relationship between body weight and fecundity and between body length and fecundity were linear in all three species. The result indicated positive strong correlation between total length (size) and fecundity in all three species. Positive strong correlations were observed between carapace length and the fecundity, ovary length and fecundity,body weight and fecundity and ovary weight and fecundity in P. indicus and P. monodon while Penaeus japonicus showed moderate positive correlations between all mentioned morphometric parameters and fecundity. There was a strong correlation between fecundity and body length in Penaeus japonicus (r =0.880), fecundity and ovary weight in Penaeus indicus (r = 0.943) and fecundity and carapace length in Penaeus monodon (r = 0.970). The estimated fecundity of Penaeus indicus varied between 989073.36 to 1380581.565 eggs for body length range 14.4 to 20.1 cm while that of Penaeus japonicus varied between 249602.2609 to 320026.71 eggs for length range 15.4 to 19.4 cm and fecundity of Penaeus monodon, with body length range 14.4 to 21.1 cm, varied between 221271.6 to 400296.288 eggs

N-acetyl-B-D-glucosaminidase and inflammatory response after cardiopulmonary bypass

OBJECTIVE: To determine the changes in activity of plasma N-acetyl-beta-D-glucosaminidase, a marker for inflammation as well as renal, pulmonary and cardiac damage and proinflammatory cytokines in patients undergoing coronary artery bypass grafting and find out the relationship between their plasma levels with clinical outcome of patients. STUDY DESIGN: Cross-sectional study. PLACE AND DURATION OF STUDY: The Aga Khan University, Karachi, from January to June 2003. PATIENTS AND METHODS: N-acetyl-beta-D-glucosaminidase (NAG) activity and concentrations of tumor necrosis factor-alpha of (TNFalpha), interleukin 6 (IL-6), interleukin 8 (IL8) and granulocyte-macrophage colony stimulating factor (GM-CSF) were monitored in plasma samples of 12 angina patients undergoing coronary artery bypass grafting (CABG), before, immediately after and 5 days post-surgical procedure. Serum glucose concentrations were also monitored in those patients. Patient\u27s clinical condition was monitored during this time period. RESULTS: No significant increase was observed in plasma NAG activity (a marker of inflammation) or in plasma levels of TNFalpha, IL-6, IL-8 and GM-CSF immediately after surgery, indicating that cardiopulmonary bypass itself does not produce any significant amount of inflammation immediately after CABG. However, 5 days post surgery, there was a significant increase in plasma NAG activity (p=0.001), TNFalpha (p=0.047) and GM-CSF (p=0.045). There was no relationship between plasma NAG activity and clinical outcome because various parameters of renal, cardiac and pulmonary functions, though slightly affected, remained within the normal limits. CONCLUSION: Increased levels of NAG and TNFalpha did not affect clinical outcome. However, data suggest that NAG can be a potential marker for inflammation and end organ damage following CABG. An increase in GM-CSF on day 5 following CABG indicates enhanced body\u27s defense mechanism against infection

Evaluation of trace metal (Hg, B, Co, and Al) levels in tissues of skipjack tuna, Katsuwonus pelamis (Linnaeus, 1758) fish from Karachi Fish Harbour, Karachi, Pakistan

The level of four heavy metals Mercury (Hg), Boron (B), Cobalt (Co), Aluminum(Al) in muscle and liver of Katsuwonus pelamis fish. Fish sample of Katsuwonus pelamis were collected from fish harbour of Karachi during January 2007 and December 2007 for metal analysis. Samples were analyzed by AAS-700. The highest length (63cm) and weight (2700g) were recorded in this studied. The mean concentrations of Hg, B, Co and Al in muscle were recorded as 0.041, 0.069, 0.041and 0.030μg/g, respectively. However, the mean concentrations of Hg, B, Co and Al in liver tissues were found as 0.673, 0.725, 0.725 and 0.498μg/g, respectively.The highest concentration of B was found in both liver and muscle tissues in pre-monsoon and monsoon, and the lowest concentration of Al was found in liver tissues at pre-monsoon, monsoon and post-monsoon seasons. The results of this study show that Hg, Co and Al accumulations of K. pelamis caught from Karachi coast were generally below the international permissible levels. Therefore, metal accumulations in K. pelamis and all other fishes have to be monitored continuously in this region for human healthy. ANOVA analysis clearly revealed that there was a significant p≤0.05 in organ of fishes. Statistically significant differences were observed in the mean metal values from different seasons and tissues (p<0.05)

Remediation and Management of Sewage Sludge

In recent times, along with urbanization, the population of the city is also increasing rapidly. In this regard, the discharge of municipal sewage is increasing year by year, which is a worrying situation for living beings as well as the environment. In fact, wastewater is an important by-product of modern industry and contributes significantly to polluting the aquatic environment. Its sources are based on many industries and anthropogenic pollutants. The nature of wastewater is organic and inorganic. Many harmful pollutants especially heavy metals are present in sewage sludge and wastewater. Phytoremediation has become a significant experimental and practical strategy to use plants to remove heavy metals from sewage waters, sludges, spillage sites, and polluted places