Pertussis over two decades: seroepidemiological study in a large population of the Siena Province, Tuscany Region, Central Italy

OBJECTIVES

To evaluate seroprevalence against Bordetella pertussis in Tuscany, a large Italian region, from 1992 to 2005 and from 2013 to 2016.

DESIGN

Seroepidemiological study.

PARTICIPANTS

1812 serum samples collected in Tuscany from subjects older than 12 years from 1992 to 2005 and from 2013 to 2016.

OUTCOME MEASURES

Specific antibody levels were determined by means of standard commercial ELISA using a dual cut-off of 50 and 125 IU/mL as markers of past and recent infection/vaccination, respectively.

RESULTS

The highest values of IgG titres were observed in 1992-1994 in all subjects (69.5 IU/mL), with prevalence values of subjects with IgG titres of >50 and >125 IU/mL of 68.3% and 23.8%, respectively. IgG titres decreased in the years thereafter (37.8 IU/mL in 2002-2005), together with prevalence values (41.7% and 8.1% in 2002-2005). In 2013-2016, both IgG titres and prevalence values showed a slight increase (50.6 IU/mL, 53.9% and 14.7%, respectively). IgG titres and prevalence followed the same age-related trend in all time periods considered, with the highest values in subjects aged 12-22 years. The lowest values were found in the age group of subjects aged 23-35 years (OR 0.54).

CONCLUSIONS

Since 2002, approximately half of the population over 22 years of age have low IgG titres and are presumably susceptible to acquiring and transmitting pertussis infection. In addition, in 2013-2016, almost one-third of subjects aged 12-22 years, that is, the age group most likely to have been vaccinated against pertussis in infancy, had low antibody levels. Improving vaccination coverage and implementing careful surveillance are therefore recommended in order to prevent morbidity and mortality due to pertussis.

Changes in the status of p53 affect drug sensitivity to thymidylate synthase (TS) inhibitors by altering TS levels

Colorectal cancer (CRC) resistance to fluoropyrimidines and other inhibitors of thymidylate synthase (TS) is a serious clinical problem often associated with increased intracellular levels of TS. Since the tumour suppressor gene p53, which is mutated in 50% of CRC, regulates the expression of several genes, it may modulate TS activity, and changes in the status of p53 might be responsible for chemoresistance. Therefore, this study was aimed to investigate TS levels and sensitivity to TS inhibitors in wild-type (wt) and mutant (mt) p53 CRC cells, Lovo and WiDr, respectively, transfected with mt and wt p53. Lovo 175X2 cells (transfected with mt p53) were more resistant to 5-fluorouracil (5-FU; 2-fold), nolatrexed (3-fold), raltitrexed (3-fold) and pemetrexed (10-fold) in comparison with the wt p53 parental cells Lovo 92. Resistance was associated with an increase in TS protein expression and catalytic activity, which might be caused by the loss of the inhibitory effect on the activity of TS promoter or by the lack of TS mRNA degradation, as suggested by the reversal of TS expression to the levels of Lovo 92 cells by adding actinomycin. In contrast, Lovo li cells, characterized by functionally inactive p53, were 3-13-fold more sensitive to nolatrexed, raltitrexed and pemetrexed, and had a lower TS mRNA, protein expression and catalytic activity than Lovo 92. However, MDM-2 expression was significantly higher in Lovo li, while no significant differences were observed in Lovo 175X2 cells with respect to Lovo 92. Finally, mt p53 WiDr transfected with wt p53 were not significantly different from mt p53 WiDr cells with respect to sensitivity to TS inhibitors or TS levels. Altogether, these results indicate that changes in the status of p53, can differently alter sensitivity to TS inhibitors by affecting TS levels, depending on activity or cell line, and might explain the lack of clear correlation between mutations in p53 and clinical outcome after chemotherapy with TS inhibitors.

[Toxic shock syndrome due to Streptococcus pyogenes: a case report]

An increasing number of severe invasive Group A streptococcal infections have recently been reported. A new syndrome similar to the staphylococcal toxic shock syndrome, defined "streptococcal toxic shock-like syndrome" is also described. We report a case of streptococcal toxic shock-like syndrome with atypical clinical onset. A 67 years old man was admitted on the emergency department because of pain in the scapular area without fever. The patient developed irreversible shock and died after 36 hours. Diagnosis was made with autopsy. We stress the possibility of infectious cause in presence of severe multi organ failure with rapid clinical exacerbation.