Escherichia coli K-12 Transcriptomics for Assessing the Mechanism of Action of High-Power Ultrasound

An investigation into the mechanisms of action on bacteria involving exposure to stress factors was conducted in this study. The effects of ultrasound on Escherichia coli K-12 MG1655 and its isogenic mutant, ∆gadW, under high power ultrasound treatments (26 kHz) were screened and identified by analysing their transcriptome differences between primary and secondary sequential treatments using RNA-Seq. This also helped to assess any developed protection for cells between different generations. According to our results, 1825 genes of all tested conditions were expressed, playing different roles in the cell. The expression of these genes is associated with DNA damage, cell membrane integrity, and also metabolic effects. The studied strains also showed different differential expressed genes (DEGs), with some genes being directly responsible for defence mechanisms, while others play an indirect effect due to cell damage. A gradual decrease in the expression of the genes, as we moved from just one cycle of ultrasound treatment to sequential treatment, was evident from a heat map analysis of the results. Overall, E. coli K-12 builds a self-protection mechanism by increasing the expression of genes involved in the respiration for increased growth, and production of flagellum and pili. It can be concluded that high power ultrasound is a technology that triggers several different defence mechanisms which directly link to E. coli.

Characterization of Indigenous Lactic Acid Bacteria in Cow Milk of the Maltese Islands: A Geographical and Seasonal Assessment

A geographical and seasonal assessment of indigenous lactic acid bacteria (LAB) in Maltese cow milk was conducted in this study. To investigate this, milk was collected from different regions of Malta during winter and summer seasons. Total viable counts (TVC) and LAB population were enumerated. Afterwards, LAB were isolated and identified by molecular methods. According to the results, similar TVC were enumerated on winter and summer samples, while highest LAB population was detected on summer samples. LAB isolates were grouped in seven different clusters which were assigned to Lactobacillus casei, Pediococcus pentosaceus, Lactobacillus plantarum, Weissella paramesenteroides, Lactobacillus rhamnosus, Lactococcus lactis, and Lactococcus garvieae. In addition, Enterococcus and Streptococcus species were also isolated. Season seemed to affect the genus / species of LAB since Lactobacillus were mainly isolated from winter samples, while Lactococcus and Enterococcus species were the main genera identified in summer samples. Regarding the geographical distribution, the majority of the Lactobacillus spp. were isolated from the South-eastern region in both seasons. In conclusion, through this study the diversity of indigenous LAB in the Maltese cow milk was monitored for the first time and highlighted that the microbial communities are affected by seasonality and geographical distribution of the farms.

Prevalence of Hepatitis C Virus Infection in Different Population Groups in Southern Italy

BACKGROUND

A cross-sectional investigation was carried out between 2000 and 2002 to assess the prevalence of hepatitis C virus infection (HCV) in Naples, southern Italy.

PATIENTS AND METHODS

Five groups of individuals were investigated, two at low risk and three at high risk for HCV infection. Blood sample sera were collected among 5,391 individuals (4,059 men and 1,332 women): 1,972 general practitioner (GP) patients and 781 employees of the National Cancer Institute (NCI) of Naples (low-risk groups); 524 male prisoners, 1,436 intravenous drug users (IDUs) and 678 hemodialysis patients (high-risk groups).

RESULTS

Overall HCV seropositivity rates ranged from 6.4% among employees of the NCI to 37.4% among male prisoners. HCV infection tended to generally increase with age, but in IDUs and in male prisoners the upward trend leveled off at 50 years of age. As compared to GP patients, IDUs (both sexes) and male prisoners had a nearly 6-fold increased risk of HCV infection, while HCV was nearly 3-fold more common among hemodialysis patients. Employees of NCI were at reduced risk of HCV infection, particularly women (odds ratio = 0.3).

CONCLUSION

The study findings confirmed the high risk for HCV infection in IDUs and identified other population groups in southern Italy that should be offered HCV screening and counselling given the severe implications of HCV infection on health.

HHV-8 prevalence, immunosuppression and Kaposi's sarcoma in South Italy

The identification of HHV-8 has opened the way for numerous epidemiological studies aimed at determining both the prevalence of HHV-8 in various sub-groups of the population (affected or not by KS) and at identifying possible cofactors necessary for the development of KS. We set up a study to evaluate the prevalence of HHV-8 in the South of Italy in KS cases, hospital patients and blood donors and to verify the role of immunosuppression in KS. In KS patients the prevalence of lytic and latent antigens were both 91% (29 positive cases). Lytic and latent antigens have prevalence rates of 20% and 15% respectively in hospital patients. In the donor group the rates were 16% for lytic antigens and 2% for latent antigens. The most recurrent chronic pathology in KS patients was cardiopathy (5 cases). The pathological case histories report 4 cases of Herpes Zoster, 6 of diabetes, one case of hepatitis C who had also had gonorrea. There was also a case, negative to HHV-8, who had had malaria after residing for three years in Oristano in Sardinia (a zone with high endemic malaria). Our study confirms that in Southern Italy there are relatively high prevalences of HHV-8 both in the general population and in blood donors and that immunodysregulation may be involved in the pathogenesis of KS. Other studies are necessary to confirm the sexual transmission of the HHV-8 virus and to better understand the natural history of HHV-8 infection.

Identification by fast atom bombardment mass spectrometry of Hb Indianapolis [beta 112(G14)Cys----Arg] in a family from Naples, Italy

We have characterized a beta 112 Arg hemoglobin in an individual from Naples, Italy, with minimal clinical problems. Blood tests revealed only slight reticulocytosis and hemoglobin instability. Furthermore, high value of alkali resistance tests for Hb F were observed. Isoelectricfocusing of globins showed the occurrence of a band migrating between the normal alpha and beta globin chains. The fairly stable variant chain was purified by fast protein liquid chromatography. A mass map of the tryptic digest was obtained by fast atom bombardment mass spectrometry clearly showing that we were dealing with a beta chain variant. However, the peptide 105-120 was missing and two new ones were present, i.e.: 105-112 and 113-120; we assumed these peptides to be generated because of the substitution of 112 Cys with an arginine residue. Further confirmation stemmed from the fast atom bombardment mass spectra of the tryptic digest submitted to a single Edman degradation step and to carboxypeptidase B further hydrolysis. The beta-globin chain variant was thus mass mapped to an extent of about 98%. Such a variant, named Hb Indianapolis, was first reported by Adams et al, as an extremely unstable variant producing the phenotype of a severe beta-thalassemia. Contrary to the findings of the above authors the occurrence of the same variant in a clinically normal individual from a Spanish family has recently been reported. Because the clinical manifestations in the latter case are similar to those observed by us, the conclusion can be drawn that beta 112 Arg hemoglobin is not a biologically unstable variant but should be regarded as belonging to the class of unstable hemoglobins giving rise to only marginal clinical problems.

Liver disease in hemophiliacs: etiological and biochemical data on 159 cases from our geographical area

A total of 159 hemophiliacs (149 treated) from our geographical area were screened in 1983 for serological evidence of HBV infection and biochemical evidence of liver disease. All were asymptomatic. HBsAg was detected in 16 cases (10%); anti-HBs and anti-HBc in 106 (67%); 19 (12%) subjects were susceptible to HBV. The HBV infection rate evaluated in 70 patients followed-up from 1980 to 1983 was 28% per year. The cumulative risk of HBV infection as well as the rate of seroconversion to HBV increased with increasing age and with increasing frequency of treatment given during the last 12 months. Anti-delta was detected in the serum of 5 (28%) out of 13 HBsAg-positive cases. Follow-up data showed that in 61% of subjects with liver dysfunction, hepatic damage could not be accounted for by HBV infection. AST and/or gamma-globulin increase was detected in 80% of patients. Abnormalities were more pronounced in HBsAg-positive cases and among them in subjects carrying anti-delta. Further follow-up studies are needed to clarify the long-term prognosis of liver disease in hemophiliacs.