Response to vaccination against different types of antigens in patients with chronic lymphocytic leukaemia.

We investigated responses to vaccination against pneumococcal polysaccharide, Haemophilus influenzae b (Hib) conjugate and tetanus toxoid antigens in 31 patients with chronic lymphocytic leukaemia (CLL) and 25 controls. While in the control group all antibody responses against different antigens were highly significant, in the patient group clear evidence for responsiveness was detected only in the case of Hib polysaccharide antigen. Certain CLL patient subgroups showed low reactivity against tetanus toxoid antigen. In conclusion, plain polysaccharide vaccines seem to be ineffective in patients with CLL. Conjugate vaccines, in turn, are immunogenic and may offer protection against infections caused by encapsulated bacteria in these patients. Further studies concerning an optimal vaccination scheme and clinical efficiency are warranted.

Aeromonas species in fish, fish-eggs, shrimp and freshwater.

Aeromonas spp. are common contaminants of fish and seafood. They also are ubiquitous in the water environment. Aeromonas spp. were identified in 27 (93%) of 29 fish, in 17 (100%) fish-egg, in two (16%) of 12 shrimp samples and in 23 (100%) freshwater samples. In total, 117 Aeromonas strains were isolated from 69 positive samples, several samples having had two or three Aeromonas species. Included in this were also 26 mesophilic Aeromonas strains isolated in association with the study on fish diseases. The distribution of the species into 13 known hybridization groups (HGs) were studied by phenotypic and molecular methods. Ribopattern analysis of SmaI digested DNA was used for the identification of HGs. The predominant HG in fish, fish-eggs and freshwater samples was A. hydrophila HG 3 because 63% (22/37), 28% (16/57) or 80% (16/20) of the strains, respectively, were in HG 3. A. hydrophila HG 2 was also common in fresh fish samples but was not identified in fish-egg samples. HG 7 was common in fish samples studied for fish diseases and in freshwater samples. Strains which were not allotted to any HGs were common (19 of 143 strains). A. hydrophila HG 1, A. caviae HG 4, A. veronii subspecies sobria or subspecies veronii HG 8/10 known to be associated with human diarrhea were uncommon in all samples. The three strains isolated from frozen shrimp during two suspected food-borne outbreaks were A. hydrophila HG 2 and HG 3.