Humoral and cell-mediated immunity (CMI) against B. pertussis was assessed in a sample of adolescent, adult and senior subjects distributed in five different geographical areas in Italy. Most (99·1%) ...subjects had IgG anti-pertussis toxin (PT) antibodies exceeding the minimum detection level ⩾2 ELISA units (EU)/ml. There were no significant differences between the genders; 6·2% samples recorded titres ⩾100 EU/ml. CMI was positive stimulation index (SI) ⩾5 against PT in 39·0% of all samples. This study suggests that B. pertussis continues to circulate in age groups that have been previously considered to be uninvolved in the circulation of this pathogen and that adolescent and adult pertussis boosters may be of value in these populations. Nevertheless, over the last 10 years, large increases in vaccination coverage rates have contributed to reduce the spread of the aetiological agent, especially in the immunized population.
This study evaluated whether a correlation exists between carriage of corynebacteria and the
lack of immunity to diphtheria toxoid. Samples of both nasal and pharyngeal secretions were
taken from 500 ...apparently healthy subjects of both sexes and of all ages and inoculated onto
Tinsdale's medium. A serum sample was also taken for ELISA test to determine the titre of
diphtheria toxin antibodies. None of the subjects carried Corynebacterium diphtheriae. Ninety-three strains of Corynebacterium spp. were isolated from 93 subjects and 86 of these were
classified to species or group level by biochemical tests. C. xerosis was the most common
(25·8%) followed by C. pseudodiphthericum (16·1%), C. jeikeium
and C. striatum (both 10·8%),
and C. urealyticum (9·7%). Three other species accounted for approximately 20% of strains
and seven were unclassified as biochemically atypical corynebacteria. Non-protective antibodies
to diphtheria toxin were found in 80 of the 93 subjects and a strong statistical association was
demonstrated between carriage of corynebacteria and non-protective levels of anti-toxin
antibodies. The remaining 13 subjects had protective levels of antitoxin antibodies. In contrast,
only 45 of the 407 non-colonized subjects had non-protective antitoxin titres. The prevalence of
carriage increased with age among males as did the percentage of non-protected subjects. The
prevalence of female carriers of corynebacteria was significantly lower. Serum samples from 12
subjects with different antibody titres to diphtheria toxoid reacted to varying degrees with
whole-cell lysates of a number of species of corynebacteria. The results suggest that a causal
relationship may exist between nasopharyngeal carriage of corynebacteria and a low anti-diphtheria toxin immune response.
A study was conducted on a new acid peroxygen system based disinfectant (Virkon), in order to assess its in vitro efficacy. The chemical was tested on different bacteria (Staphylococcus aureus, ...Pseudomonas aeruginosa, Escherichia coli), spores (Bacillus subtilis) and on the Hepatitis B surface antigen (HBsAg), and compared in its activity with phenol and glutaraldehyde (calculation of the 'phenol coefficient' and the 'glutaraldehyde coefficient'). The constancy of speed of disinfection, the coefficient of concentration, the minimal inhibitory concentration (MIC) were also determined, and the destruction of the HBsAg antigenic activity was studied using an ELISA kit. The sporicidal efficacy of Virkon was assessed by cultivating spores in agar nutrient after contact with different dilutions of the disinfectant. The results of the tests showed that Virkon has a high concentration coefficient (mean value of k: 0.374/min) and a wide range of action. The low MIC demonstrates how little concentrations of Virkon can inactivate all studied bacteria. The disinfectant was also able to destroy the hepatitis B surface antigen, and it demonstrated good activity against spores, especially if used in physiologic solution. These characteristics, coupled with the absence of irritation or toxic effects on animals showed by other studies, make wide fields of application for the new disinfectant foreseeable.
Preprotachykinin-A (PPT-A) mRNA levels in discrete rat brain regions were examined. Analysis of silver grains revealed a 19.2% and 31.5% statistically significant decrease in PPT-A mRNA in the dorsal ...and ventral caudate putamen (d-CPu and v-CPu), respectively, a 30% lower expression of PPT-A mRNA in the bed nucleus of the stria terminalis (BNST), a 33.7% decrease in PPT-A mRNA in the habenula (Hb), and a 30% decrease of PPT-A mRNA levels in the posterodorsal part of the medial amygdala (MePD). Results show that aging of the CNS is associated with widespread changes in tachykinin gene expression, suggesting that alterations in the tachykinergic system may have implications in the physiopathology of the elderly.
A polycentric study was carried out between 1993 and 1995 in order to evaluate diphtheria immunity on a representative sample of population from different areas of Italy. To determine diphtheria ...antitoxin, sera from 5187 apparently healthy subjects, divided according to sex and age groups, were titrated using an ELISA indirect method. A basic protective titre of diphtheria antitoxin (>0.01
IU
ml
−1) was found in 4080 (78.6%) subjects. No statistically significant differences between males and females were observed. Our findings show that the proportion of susceptibles increases with age and a high proportion of adults no longer has diphtheria antitoxin at protective levels since toxigenic
C. diphtheriae circulation is presently lacking in Italy.
Immunity to diphtheria in Siena GASPARINI, R.; POZZI, T.; FRAGAPANE, E. ...
Epidemiology and infection,
10/1997, Letnik:
119, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The aim of this study, carried out in 1993, was to evaluate diphtheria
immunity in Siena.
Diphtheria antitoxin levels were measured by means of the immunoenzymatic
test (ELISA) in
serum samples of ...602 apparently healthy subjects (239 males and 363 females)
of all ages
residing in Siena. According to widely used criteria, 6% of the total population
were
susceptible to diphtheria (antibody levels <0·01 IU/ml),
71% had basic protection
(0·01–0·09 IU/ml) and 23% were fully protected
(ges 0·1 IU/ml). The results suggested that a
high proportion of young population had a protective level of immunity
against
diphtheria, that susceptibility increased with age and a smaller proportion
of males
(2·9%) than females
(8·3%) were unprotected; this difference was statistically significant.
Our results suggest that it
may be useful to revaccinate adults with low levels of diphtheria toxoid
so
that the percentage
that remains unprotected does not put the community at risk of an outbreak
of diphtheria.
The present study examined the effects of ageing on preprotachykinin-A (PPT-A) mRNA levels in discrete regions of the rat brain. Semiquantitative analysis of silver grains revealed a 16% ...statistically significant decrease in PPT-A mRNA in the shell of the nucleus accumbens (AcbSh), a 27.6% statistically significant lower level of PPT-A mRNA in the olfactory tubercle (Tu), a 19.2% and 31.5% statistically significant decrease in PPT-A mRNA in the dorsal and ventral caudate–putamen (d-CPu) (v-CPu), respectively, a 30% statistically significant lower expression of PPT-A mRNA in the bed nucleus of the stria terminalis (BNST), a 33.7% statistically significant decrease in PPT-A mRNA in the habenula (Hb) and a 30% statistically significant decrease of PPT-A mRNA levels in the postero-dorsal part of the medial amygdala (MePD). No changes in PPT-A mRNA levels were found in the nucleus accumbens, core (AcbC), in the islands of Calleja (Icj), and in the medial preoptic area (mPOA). These results show that ageing of the central nervous system (CNS) is associated with widespread changes in tachykinin gene expression, suggesting that alteration in the tachykinergic system may have implications in the physio-pathology of the elderly.
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