Salmonella isolated from animals and feedstuffs in Sweden during 1983-1987.

This survey describes the frequency of Salmonella in animals and feedstuffs isolated in Sweden 1983-1987. Since 1949 National Veterinary Institute (NVI) has published such reports every fifth year. During the period of this report 760 outbreaks of Salmonella were reported in animals. This includes both domestic and wild animals. The corresponding figure for the previous period was 1266 outbreaks. 56 different serovariants were reported, 17 of these were new to Sweden. In cattle and swine there were a decrease of outbreaks. In poultry 86 outbreaks were reported, compared with 220 outbreaks during the previous five-year period. Swedish feed producing plants are checked both voluntary and compulsory, for the presence of Salmonella in raw materials, scrape and dust samples and compound feed. During 1983-1987 a total of 236 strains at Salmonella were isolated. This is the lowest incidence found during the last 15 years. All consignments of feedstuffs of animal origin intended for import to Sweden has to be examined for the presence of Salmonella. During 1983-1987 8.6% of the consignments were positive for Salmonella and were thus not allowed to be used in Sweden.

Salmonella isolated from animals and feed stuffs in Sweden during 1978-1982.

Regulations concerning the control of Salmonella in animals are more strict in Sweden than in most other countries, though a certain liberalization took place in 1982. The main purpose of these regulations is to prevent transmission of Salmonella infections from animals to man. Veterinarians and laboratories are obliged to report all Salmonella cases to the veterinary authorities. The cases are recorded by the Swedish Board of Agriculture. During the period of this report, 1978-1982, 1266 outbreaks of Salmonella in animals were recorded in Sweden. Isolated strains belonged to 78 different serotypes. The most frequent serotypes were S. typhi-murium (38.5% of the recorded cases) and S. dublin (37%). S. dublin was isolated mainly from cattle, while S. typhi-murium was isolated from a wide range of animal species. Next in frequency are some serotypes isolated mainly from chicken, at rates around 2%: S. livingstone, S. liverpool, and S. agona. Of the 78 isolated serotypes, 25 were never isolated before from animals in Sweden. There were 687 outbreaks of Salmonella recorded in cattle. Predominant serotypes are S. dublin (67% of the outbreaks in cattle) and S. typhi-murium (28%). The outbreaks of S. dublin, like earlier in the sixties and seventies, occurred mainly in south-eastern Sweden. The recorded occurrence of Salmonella in swine continued to decrease. During this period only 37 outbreaks were diagnosed. Of these more than half were caused by S. typhi-murium. S. choleraesuis was isolated from 6 cases only.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies to Clostridium botulinum toxins in free-living birds and mammals.

Naturally-occuring antibodies against Clostridium botulinum toxins were found in Cathartes aura (turkey vultures), Canis latrans (coyotes) and Corvus brachyrhynchos (crows) by the passive hemagglutination (PHA) test and verified by the serum neutralization (SN) test. The prevalence of IHA antibodies was 18 of 20 vultures (90%), 5 of 12 crows (42%) and 25 to 110 coyotes (23%). Vultures and coyotes were seropositive by the PHA test against A, B, C, D, and F toxins. The highest antibody titer 1:8192 was in vulture serum against type C. In descending order, the highest antibody levels were against type C, D, F, E, A and B toxins.

Isolation of Yersinia enterocolitica from swine at an abattoir in Sweden.

Yersinia enterocolitica is presented from a taxonomic point of view. A review about the increased frequencies of isolations of Y. enterocolitica from domestic and wild animals in Europe is given. Recent studies from different countries strongly suggest swine as a source of Y. enterocolitica infection to humans. The frequencies of isolation of the O-group I (serotype 3) of this bacteria from swine at a Swedish abattoir is presented. The occurrence of positive cases in lots of swine sent to slaughter from different herds range from 0.6 to 8.0%.

Differentiation of antibodies against Brucella abortus and Yersinia enterocolitica by enzyme-linked immunosorbent assay.

The enzyme-linked immunosorbent assay (ELISA) was found to be from ten to hundred-fold more sensitive than commonly used tube agglutination text. The ELISA using both direct and indirect inhibition assays revealed antigenic differences between Brucella abortus and Yersinia enterocolitica O-group V (serotype 9), which are undetected by commonly used serological routine tests. The results point to the possibility that the ELISA assay can be used as a serological method for differentiation between antibodies against different Brucella species and Y. enterocolitica O-group V.

[Zoonotic aspects of Yersinia enterocolitica infections (author's transl)]. / Zoonotiska aspekter på Yersinia enterocolitica-infektioner.

Yersinia enterocolitica (Y.e.) is presented from taxonomic point of view. The increased accounts of isolates performed during the last years from both humans and animals are described. Y.e., which is of great interest both in human and veterinary medicine, has been isolated in an increased frequency, from domestic as well as wild animals, from different foods, and also from drinking waters. The modes of transmissions are in many parts unknown, but clinical and epidemiological data suggest that the majority of infections both in humans and animals occur through the digestive tract. From different countries reports have been presented on the assumption that swine are playing an important role as reservoirs for infections in man. Foods contaminated with Y.e. bacteria either, primarily or secondarily, seem to be an important source of infections in the occurrence of Y.e. outbreaks.

[The background of the serological cross-reaction between Yersinia and Brucella and the possibility of differential diagnostics by the ELISA technique and the electroimmuno assay (rocket electrophoresis) (author's transl)]. / Bakgrunden till den serologiska korsreaktionen mellan Yersinia och Brucella samt möjligheter till differentialdiagnostik med ELISA-teknik och raketelektrofores.

A strong serological cross-reaction appears between different species of genus Brucella and Yersinia enterocolitica (Y.e.) serotype 0--9, which seriously complicates the diagnostic works of brucellosis and yersiniosis both in humans and animals. This cross-reaction makes it impossible to perform a differential serological diagnosis using common routine procedures such as the agglutination test and the complement fixation test. By the use of immunological, immunochemical and structural chemical methods it has been shown that the common antigenic structures of Brucella and Yersinia are situated in the lipopolysaccharides (LPS) of the cellwalls. In order to do structure analysis gaschromatography in combination with mass spectrometry of LPS from Brucella and Yersinia bacteria has been achieved. The results show that two monosaccharides (glucose and galactose) constitute common components of the LPS-molecules. A discovered cross-reaction between Y.e. 0--9 and Salmonella urbana (0--30) confirms the hypothesis that glucose and galactose are responsible for the serological cross-reaction between Brucella and Y.e. 0--9. An enzyme-linked immunosorbent assay (ELISA) has been developed in order to be used as a differential routine test. The results show that by using ELISA, a differentiation between antibodies against Y.e. 0--9 and B. abortus can be done with high sensitivity and accuracy. Another differential diagnostic system has been developed by the use of electroimmuno assay (rocket electrophoresis). This method raises the possibility of a rapid and a simple qualitative differentiation of antibodies against Brucella and Yersinia.

Periurethral aerobic microflora of pregnant and non-pregnant women.

Seventy-two pregnant and 88 non-pregnant women were examined to see whether the periurethral region had been colonised with group B streptococci (Streptococcus agalactiae), enterococci, and Gram-negative rods belonging to the Enterobacteriaeceae. A semi-quantitative method was used for periurethral sampling, and paired urethral swabs were also collected to compare the isolation rates of group B streptococci from the two sites and with the two sampling methods. A higher isolation rate was found with periurethral sampling. Most specimens showed no or scanty growth of Gram-negative rods. Pregnancy was often associated with heavy growth of enterococci. Sampling performed during menstruation and while oral contraceptives were being used produced high isolation rates of group B streptococci. These results seem to suggest that the periurethral area might protect against genital colonisation with group B streptococci as it does against urinary tract infection and that hormonal factors influence the carriage of these organisms.

Serologic studies on porcine strains of Haemophilus parahaemolyticus (pleuropneumoniae): agglutination reactions.

Fifteen strains of Haemophilus parahaemolyticus (pleuropneumoniae) represented by 6 American isolates, 6 Swedish isolates, and 3 reference strains of Nicolet's serotype 1, 2 and 3, were used in serologic studies by agglutination and agglutinin-adsorption tests. By whole cell-agglutination tests in rabbit antiserums, 3 additional serotypes, 4, 5, and 6, were identified. All strains had strong serotype-specific agglutinating properties. Occasional weak cross reactions could be eliminated by appropriate adsorptions without effect upon type-specific reactivity. The Swedish isolates were assigned to serotypes 2, 3, 4, and 6, and the American isolates, to serotypes 4 and 5. All European isolates were distinct from 5 of the 6 American strains. An American culture isolated from a steer and another from a lamb were identical in their agglutination reactions with the porcine isolates of serotype 5. The serotyping of isolated strains is important in the epizootiologic and immunologic studies of H parahaemolyticus infections.

Cultural and biochemical criteria for the identification of haemophilus spp from swine.

Twenty-two Haemophilus cultures of types prevalent in swine and of different geographic origins were subjected to biochemical and cultural examinations. Three subgroups were identified: One was unrease-positive, produced porphyrin from delta-aminolevulinic acid, and grew on infusion mediums supplemented only with V factor; the 2nd was unrease-negative, porphyrin-positive, and grew only on serum-enriched mediums with added V factor; and the 3rd was unrease-negative, porphyrin-negative, and grew only on serum-enriched mediums with added V and X factors. The groups generally corresponded to Haemophilus parahaemolyticus, Haemophilus parasuis, and Haemophilus suis, respectively. By means of the unrease and porphyrin tests, it was possible to assign, presumptively, porcine haemophilus cultures to 1 of the 3 species. Other tests, such as beta-galactosidase, hemolysis, and fermentation of carbohydrates were of secondary value in differentiating between these species.

Recent experiences with the Salmonella-O-1-phage in routine diagnostic work.

Sensitivity to the O-1-phage was tested on 5287 Salmonella strains isolated in the course of routine diagnostic work over the period 1971-1973. 3380 (99,2%) strains of the B group, 676 (97,8%) of the C group, 840 (98,8%) of the D group, and 195 (83,0%) of the E group strains were sensitive to the O-1-phage. 92 of the 5 287 strains belonged to other O-groups in the Kauffmann-White scheme; 91,3% of these were phage-positive. 5274 of the strains belonged to subgenus I and only 100 of them were not sensitive to the O-1-phage. A total of 13 strains belonged to subgenera II, III, and IV. The O-1-phage was considered to be suitable for the identification of Salmonella bacteria. It should, however, be observed that monophasic strains belonging to subgenus III and strains belonging to subgenus IV are usually not sensitive to the O-1-phage. Of the total number of strains, 98,0% were sensitive to the O-1-phage.

[Isolation of Campylobacter fetus in two herds of sheep in Sweden (author's transl)]. / Isolering av Campylobacter fetus (syn. Vibrio fetus) i två svenska fårbesättningar

In two herds of sheep with numerous abortions Campylobacter fetus subspecies intestinalis was isolated from fetuses, fetal membranes, and faecal specimens. In herd A, with good hygiene, 12 ewes out of 250 aborted. In herd B, with poor hygiene, 54 out of 171 ewes aborted and 14 of them died; for a further 9 ewes the lambs died postnatally. The clinical course in both herds shows that proper supervision and possibilities of prompt isolation of aborting ewes can substantially reduce the spread of infection within the herd. The isolated strains of C. fetus subsp. intestinalis were catalase-positive, did not grow in deep culture on 0.5% semisolid agar, reduced nitrate, did not grow in 3,5% NaCl, but grew in 1% ox bile and 1% glycine. All the strains were negative with respect to H2S production on TSI but positive on lead-acetate strips. In serological tests, positive agglutination titres were demonstrated only in aborting ewes from herd B. Positive titres were also demonstrated in a ram from the same herd.

Enzyme-linked immunosorbent assay (ELISA) for titration of antibodies against Brucella abortus and Yersinia enterocolitica.

An enzyme linked immunosorbent assay (ELISA) using phenolwater extracted lipopolysaccarides as antigen was used for detection and quantitation of antibodies against Brucella and Yersinia bacteria in rabbit antisera. ELISA was found to be from ten to hundred-fold more sensitive than the commonly used tube agglutination assay (Widal). In addition, both direct and inhibition assays using ELISA revealed antigenic differences between Brucella abortus and Yersinia enterocolitica O-group V, previously undetected in tube agglutination and complement fixation studies. These data raise the possibility of a sensitive and specific assay for detection of anti-Brucella antibodies in human sera.

The persistence of group B streptococci in families.

Four years ago the relative occurrence of group B streptococci was studied in a group of 118 term pregnant women of which 17 were B-streptococcal carriers. Of these, 15 were investigated in connection with the delivery. 11 of these women were reexamined 45-50 months after delivery together with their families. A high frequency of positive cultures without symptoms (50%) was found in this small group of women and their husbands compared with male and female control groups. Persistence seems to be common, a fact to be remembered in subsequent pregnancies.