R plasmids coding for supra-levels of gentamicin, tobramycin and sisomicin resistance in Proteus morganii and P. mirabilis: high-level resistant strains from two hospitals.

Transfer of high-level gentamycin-tobramycin-sisomycin resistance could be easily demonstrated in strains of P. morganii and P. mirabilis which emerged, in two hospitals, at the end of 1976. First such strains were demonstrated in a patient of a urological ward who died, in September 1976, from generalised sepsis caused by a high-level gentamycin-tobramycin-sisomycin-resistant P. morganii. Since that event, at least nine such strains were isolated in 1976, and the presence of transferable resistant to the antibiotics listed plus other antibacterial substances including carbenicillin and more classical antibiotics could be demonstrated either by a high-frequence direct transfer to suitable recipient strains of Gentamycin or Tobramycin resistance, or by indirect selection, i.e. by analysis of exconjugants selected with kanamycin, streptomycin or carbenicillin. Further numerous strains of P. morganii highly resistant to gentamycin, tobramycin and sisomycin (M.I.C. over 128 mcg/ml) still emerge from wards in the two hospitals monitored and their transferability is under experimental study. It is stressed that, in order to demonstrate a transfer of gentamycin or tobramycin resistance in strains resistant to these substances, it is inevitable to examine properly also exconjugnants showing direct transfer to other, more classical antibiotics. We could not demonstrate, in our strains, any prodromal signs of resistance to netilmycin or amikacin.

Transplacental antibodies. Part II: Maternal antibodies against the toxins of C. diphtheriae and C. tetani.

Examinations of 297 sera for diphtheria antitoxin and 160 sera for tetanus antitoxin were carried out in 1981. All sera were obtained from the cord blood of mothers between 15 and 34 years of age. The mothers were divided into four age groups each of which was further subdivided into the primipara and multipara subgroups. The aim was to assess the age-specific variations in response to active immunization against diphtheria and tetanus. The protective level of diphtheria antitoxin (at least 0.01 I.U./ml) was recorded in the serum of 96.3% of examinees and the rates of seropositivity were found to fall with increasing age. The protective level of tetanus antitoxin (at least 0.1 I.U./ml) was found in the serum of 95.2% of mothers. The serologic response encountered in groups of older mothers was a clear-cut demonstration that the country-wide mass immunization against tetanus carried out between 1974 and 1975 was highly effective and fully justified. The variations in the diphtheria and tetanus antitoxin levels found in the primipara and multipara subgroups were not statistically significant.

Transplacental antibodies. Part III: Maternal antibodies against polioviruses, M. parotitidis and M. parainfluenzae.

In 1981 we examined 247 sera for the presence of antibodies against all three types of poliovirus and 253 sera for antibodies against M. parotitidis and three types of M. parainfluenzae viruses. The sera were obtained from the cord blood of mothers between 15 and 34 years of age. All mothers were divided into four age groups, each with primipara and multipara subgroups. The rate of seropositivity for type 1 and type 2 poliovirus-specific antibody was in all age groups higher than 90%, the overall seropositivity rate for type 3 poliovirus antibody was 83.6%, with 73.1% as the lowest rate for age group of youngest mothers. Significant seropositivity variations between the primipara and multipara subgroups were recorded only for type 3 antibody in the two age groups of oldest mothers (25-29 and 30-34 years). This is consistent with the assumed booster effect of Sabin vaccine strains on mothers of families with more than one child. Antibodies specific to mumps virus were present in the cord blood of 78.6% of all mothers and the rates of seropositivity were found to rise with the increasing age. Seropositivity for M. parainfluenzae type 1-specific antibody was demonstrated in 95.8%, for type 2-specific antibody in 98.9% and for type 3-specific antibody in 100% of mothers, which is suggestive of high herd immunity levels in the population.

Transplacental antibodies. Part I: Maternal antibodies against B. pertussis and B. parapertussis.

In 1981 a set of 256 of the umbilical cord blood collected from mothers between 15 and 34 years of age was serologically examined for specific antibodies against B. pertussis and B. parapertussis infections. The mothers were divided into four age groups, each with primipara and multipara subgroups, with the aim to assess age-related variations in specific immunity levels acquired as a consequence of active immunization against pertussis, or by clinical or subclinical infection with B. parapertussis (no specific immunization against B. parapertussis infection is carried out in Czechoslovakia). The percentage of mothers with B. pertussis-specific antibody was found to fall from 81% and 70% in the two younger age groups (15--19, 20--24 years) to 21.3% and 16.3% in the two older age group (25--29, 30--34 years). The variations between the primipara and multipara subgroups were not statistically significant. Antibody against B. parapertussis infection was present in 38.6% of all mothers, which is suggestive of a relatively high circulation of this agent in the population. In the two older age groups (25--29 and 30--34 years) multiparous mothers were found to have B. parapertussis antibodies at significantly higher rates than primiparous mothers, which seems to confirm the theory that B. parapertussis infection may serve as booster to immunity in mothers of families with more than one child.

Transferable resistance to cephalosporins, ureidopenicillins and trimethoprim.

Transferable resistance to classical Cephalosporins emerged three years ago among Enterobacteriaceae simultaneously in several hospitals and was associated with resistance to other betalactam drugs, i.e. with a transmissible TEM-like betalactamase. A systematic survey of incidence of R plasmids in Proteus sp. lead, in two district PHLs, to demonstration of transferable Azlocillin resistance. This resistance was most frequently associated with that for Carbenicillin, but also strains susceptible to CAR but resistant to AZL have been isolated. Trimethoprim resistance was in this country first described by Schon, but, since then, it is now frequently found transferable in polyresistant strains from hospitals, resistant also to betalactam antibiotics, Gentamicin and other drugs.

Surveillance of pertussis in the CSSR. IV. Immunological surveys of antibodies to pertussis and parapertussis in the Bohemian regions and in Slovakia in 1958 - 1971.

A comparison of the results of repeated immunological surveys with the notification of morbidity and mortality to pertussis and parapertussis revealed direct dependence and simultaneously confirmed the effectiveness of Czechoslovak vaccine. Immunological surveys should be continued in spite of the fact that morbidity of pertussis is low at present, because immunological surveys may lead to timely detection of shortcomings in the quality of vaccination and vaccine. The results after 14 years of systematic vaccination and revaccination and consequent follow-up to the state of immunity in the population and of other factors in the pertussis surveillance programme rank among the other achievements of epidemiology and hygiene in Czechoslovak health services. Contemporary immunological surveys show that the state of immunity in Czechoslovak child population is such as to exclude the occurrence of pertussis in epidemics in the nearest future. The situation is different in parapertussis where epidemic incidence is still possible and where epidemics regularly occur in children of prae-school age.