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Biomedical subjects

B Hovelius

Publications and source records attributed to B Hovelius.

71 records · Page 4Linked to original sources
PubMed1979

Haemagglutination by Staphylococcus saprophyticus and other staphylococcal species.

Staphylococcus saprophyticus was found to differ from Staphylococcus epidermidis and Staphylococcus aureus by its ability to agglutinate sheep erythrocytes. On testing 30 strains of each species, 28 strains of S. saprophyticus and one strain each of the other two species, caused agglutination. Twenty-eight of 30 strains of staphylococcus cohnii and Staphylococcus xylosis failed to cause haemagglutination. The haemagglutinating activity of S. saprophyticus, when using a 10 per cent bacterial suspension was demonstrated in dilutions of 1:2-1:32. It was reduced twofold, at most, when exposing the bacteria to 56 degrees C for 30 minutes, while no agglutination could be demonstrated after treatment for 10 minutes at 86 degrees C. No haemagglutination could be demonstrated after treatment of the bacteria with 5 per cent solution of trypsin. Treatment of S. saprophyticus with 0.1 M EDTA did not affect the haemagglutinating activity, whereas exposure of the bacteria to 10 per cent trichloroacetic acid reduced the activity. The haemagglutination was D-mannose-resistant, and it was inhibited by homologous rabbit antiserum. The agglutinates dispersed when heated at 45-56 degrees C for 30 minutes. A few of the strains of S. saprophyticus tested also agglutinated human, bovine, and guinea pig erythrocytes.

Animals↗
PubMed1979

Surface properties of Staphylococcus saprophyticus and Staphylococcus epidermidis as studied by adherence tests and two-polymer, aqueous phase systems.

S. saprophyticus is an established pathogen in man, devoided of characteristics associated with pathogenicity in Staphylococcus aureus. The ability of this species to attach to cells from regions, viz. the urinary tract, where it acts as an invador and to cells from areas where it is known as a commensal, was compared to its behaviour in this respect with another staphylococcal species, viz. S. epidermidis. S. saprophyticus showed a preferenital adherence to human exfoliated urogenital cells, when compared with its ability to attach to skin and buccal cells from man and also when compared with procine cells from these regions. The profound ability to adhere to human exfoliated urogenital epithelial cells by far exceeded that of S. epidermidis, while no such species difference was found when testing porcine cells (S. saprophyticus is unknown as a urogenital tract pathogen in pigs). When studied in a two-polymer, aqueous phase system, S. saprophyticus and S. epidermidis were found to have a negative surface charge at pH 7.2, but the former carried a considerably higher surface charge density. Both staphylococcal species exhibited a poor hydrophobic interaction liability. These physico-chemical surface characteristics are briefly discussed with regard to the differential bacteria-cell interactions of these species.

Adhesiveness↗
PubMed1979

Staphylococcus saprophyticus in the aetiology of nongonococcal urethritis.

The occurrence of Staphylococcus saprophyticus, Chlamydia trachomatis, and Neisseria gonorrhoeae in urethral specimens of 252 men attending a venereal disease clinic was studied. When using a selective broth medium containing novobiocin and nalidixic acid, Staph. saprophyticus was isolated from 20.8% of 178 men with symptoms of urethritis and from 14.9% of 74 men without such symptoms. Staph. saprophyticus was found significantly less often in controls (7.1% of 56) than in the men with symptoms of urethritis. In the 35 men from whom Staph. saprophyticus was recovered more than 10 leucocytes per high power field in urethral smears occurred more often than in those from whom this organism, or either of the other two agents, were not isolated. No differences were found in the symptoms reported by the men harbouring Staph. saprophyticus or C. trachomatis or those with negative cultures. The results of the present study tend to suggest that Staph. saprophyticus is the aetiological agent of some cases of nongonococcal urethritis.

Adolescent↗
PubMed1979

Upper respiratory tract spread of group B streptococci type I b in a kindergarten.

In a kindergarten with 42 children and 17 female staff members, an epidemic of group B streptococcal carriage in the upper respiratory tract occurred. In the middle of February 1978, 6 children and 5 adults carried type I b streptococci in the throat while only 2 of these 11 were carriers 2 weeks later. Only one other streptococcus, belonging to type II, was found in the throat specimens. Five strains other than type I b were found in the urogenital tract of the staff. Three type I b throat carriers were also urogenital carriers of this type. The spread of type I b streptococci could have resulted from co-spreading with other upper respiratory tract pathogens found, including group A streptococci of type 12. Haemophilus influenzae, Branhamella catarrhalis and pneumococci. Estimation of antibodies with radiolabelled protein A indicated an immune response to type I b, but not to types I a, II or III group B streptococci in the staff compared with healthy blood donors.

Adolescent↗
PubMed1979

Attachment of bacteria to exfoliated cells from the urogenital tract.

To establish urogenital infections, organisms must adhere to the mucosal lining. A differential adherence capacity among various bacterial species was observed when exfoliated urethral and urothelial cells were tested in an in vitro system. No difference in the adherence capacity of a particular species was observed when tested with exfoliated cells obtained from voided urine from different healthy individuals of the same sex. Escherichia coli harvested directly from urine specimens of patients with significant bacteriuria showed a significantly higher capacity to adhere than when obtained from the primary isolation plate. Staphylococcus saprophyticus adhered significantly better to urothelial cells than did Staphylococcus epidermidis. Adherence did not differ when the tests were performed in ultrafiltrated, infected and noninfected urine. Variations of the osmolality did not influence the adherence rate of E. coli. Gonococci showed an increased capacity to adhere when tested in urine of increasing acidity. Gonococci producing T1 colonies adhered by significantly higher numbers per cell than such bacteria producing T4 colonies.

Bacteriuria↗
PubMed1978

Binding of aggregated IgG in the presence of fresh serum by group A streptococci producing pharyngeal infection: possible connection with types frequently involved in acute nephritis.

109 streptococcal strains, belonging to diverse serological groups and types, were investigated as regards their capacity to bind IgG aggregates in the presence of fresh serum. Strains capable of such binding were not found in groups B,C,D,E,G,L,M or N. Such binding was restricted to a few types of group A streptococci: the potentially nephritogenic types 2, 6 and 12, and four strains belonging to type M 39, M 46 and M 22 or M 62, the nephritogenic capacity of which is unknown. Two of five strains isolated from patients with acute post-stretococcal glomerulonephritis (AGN) and 19/28 type T 12, SOR-strains, isolated during an epidemic in a kindergarten with associated cases of AGN, were found to bind aggregates. The findings suggest a possible association between capacity to bind aggregates in the presence of serum and the serological types of group A streptococci involved in acute nephritis following pharyngeal infection.

Acute Disease↗
PubMed1977

On the diagnosis of coagulase-negative staphylococci with emphasis on Staphylococcus saprophyticus.

This study concerns the diagnosis of coagulase-negative staphylococci, with special emphasis on novobiocin-resistant species, vis S. saprophyticus, S. cohnii and S. xylosus. Disc diffusion tests for novobiocin were found useful in the differential diagnosis of coagulase-negative staphylococci isolated from urine specimens, but not from pus and blood cultures. We report on the resistance of S. saprophyticus to nalidixic acid and the use of this characteristic in the diagnosis of coagulase-negative staphylococci known to be novobiocin-sensitive, but which have subsequently acquired resistance to novobiocin. The results of different tests for betalactamase production in S. saprophyticus are presented. "Clover leaf" tests suggested such a production in about half of the strains studied, while no strain produced betalactamase as indicated by tests using chromogenic cephalosporin or benzylpenicillin in capillary tube tests. -The failure of tests for nitrate reduction, glucose consumption and of cultrues of urine on MacConkey's agar in the diagnosis of urinary tract infections caused by S. saprophyticus, is documented. The concept "significant bacteriuria" in the diagnosis of S. saprophyticus infections of the urinary tract above the bladder neck is also considered.

Bacteriological Techniques↗
PubMed1977

Microcalorimetry as a tool for evaluation of blood culture media.

Evaluation of optimal compositions of blood culture media has called for extensive and laborious work in comparative studies of large series of clincal specimens. Bacterial growth is accompanied by heat production, and calorimetry provides an analytical tool for its detection and quantification. A twin microcalorimeter of the heat conduction type was used to register heat effects in experimentally infected blood cultures. When studying Escherichia coli and Staphylococcus aureus, larger heat effects were produced with 0.05% sodium polyanetholsulfonate than with 600 IU of heparin per ml, which was also the case when using 10% sucrose. The addition of IsoVitaleX (BBL) increased the heat effects produced by the two species mentioned, whereas it had the opposite effect in cultures of Neisseria meningitidis. The present study indicates that microcalorimetry is a valuable and time-saving tool for the evaluation of optimal compositions of bacterial culture media.

Blood↗
PubMed1976

The incidence and aetiology of respiratory tract infections in general practice--with emphasis on Mycoplasma pneumoniae.

The incidence of respiratory tract infections in patients seeking medical advice at a community care centre (Dalby) during 1973 and 1974 was studied. About every third patient seen at this primary health station presented with signs of such infections. In the age groups less than 10, 10-19, 20-39, 40-59 and greater than or equal to 60 years, respiratory tract infections accounted for 65, 45, 32, 18 and 9% of the fotal number of diagnoses made during 1974. The aetiology of acute respiratory tract infections in a series of patients seen at this health station was studied. The series included randomly selected cases, but excluded children under seven years of age and patients presenting with signs of acute otitis media and tonsillitis. Attempts to establish the aetiology were made on the basis of the history, the clinical examination, and cultures for beta-haemolytic streptococci and Mycoplasma pneumoniae, complement foxation tests for influenza A and B, para-influenza 1, 2, and 3, adeno, cytomegalovirus and respiratory syncytial virus, and Chlamydia psittaci. Paul-Bunnell test and tests for cold agglutinins were also performed. With this test battery, an aetiological diagnosis was obtained in only 33% of the 101 patients studied. The findings suggest an infection with M.pneumoniae in 16%, with beta-haemolytic streptococci in 9%, and with viruses (adeno and para-influenza) in 7% of the patients. The present communication highlights the role of M.pneumoniae in upper respiratory infections, as few data have appeared on such infections in patients seen in general practice. The difficulty of establishing the aetiology of respiratory tract infections and the consequent treatment dilemma is discussed.

Adolescent↗
PubMedDate not supplied

Staphylococcus saprophyticus as a common cause of urinary tract infections.

Until the last decade, coagulase-negative staphylococci occurring in urine specimens were usually regarded as a contaminant. In the early 1970s, i.e., more than ten years after the original demonstration of Staphylococcus saprophyticus in urine specimens, this species became recognized as a frequent cause of urinary tract infections (UTI). In young women, S. saprophyticus is, after Escherichia coli, the second-most-frequent causative agent of acute UTI. Patients with UTI caused by S. saprophyticus usually present with symptomatic cystitis. Signs and symptoms of renal involvement are also often registered. The urine sediment of a patient with UTI caused by S. saprophyticus has a characteristic appearance microscopically. Chemical screening methods for bacteriuria do not always succeed in diagnosing UTI caused by S. saprophyticus. Even when such an infection occurs above the neck of the bladder, low numbers of colony-forming units (less than 10(5) cfu/ml) of S. saprophyticus are comparatively often found in the bladder and voided urine. S. saprophyticus is usually susceptible to antibiotics commonly prescribed for patients with UTI, with the exception of nalidixic acid. The bacterium has a capacity for selective adherence to human urothelium. It causes direct hemagglutination. The adhesin for S. saprophyticus is a lactosamine structure. This staphylococcal species produces an extracellular enzyme complex that can inhibit growth of both gram-positive and gram-negative bacteria.

Adhesiveness↗
PubMedDate not supplied

Respiratory tract infections in children with recurrent episodes as preschoolers.

The occurrence of respiratory tract infections (RTI) in 41 school-age children, who had recurrent RTIs treated with antibiotics as preschoolers, was followed prospectively for two years through diary reports by parents and medical consultations, and compared with that in 29 children of the same age and socio-economic background, who had few or no such infections as preschoolers. During the two-year follow-up, a greater number of episodes of RTI and a longer mean duration of such episodes were reported in the diaries concerning the children with recurrent bacterial RTIs as preschoolers compared with the controls (p less than 0.01). The annual incidence of bacterial RTI from birth onwards decreased with age among the children with recurrent episodes as preschoolers, unlike in the control group, where the incidence remained consistently low, the difference in incidence being significant up to the age of eight years (p less than 0.01). Acute otitis media was the predominant bacterial RTI in preschoolers, and acute tonsillitis in school-age children. There was a tendency toward a greater incidence of other types of disease and complications/sequelae of infections among the RTI-afflicted group than among the controls, both as preschoolers and as school children. Our findings suggest that certain children constitute a group with high morbidity, susceptible to RTIs and other illnesses over a rather long period of years.

Adolescent↗
PubMedDate not supplied

Children with recurrent respiratory tract infections tend to belong to families with health problems.

Children (7-11 years of age) who had recurrent respiratory tract infections (RTI) treated with antibiotics as preschoolers (n = 41), and their families were compared with regard to medical and social factors to families with children of comparable age who had had no such infections as preschoolers, or only isolated episodes (controls; n = 29). All the children studied had attended day-care centres as preschoolers. The two groups of children did not differ with regard to socio-economic conditions or age at admission to day-care centres. There was a difference in the two groups with regard to signs noted at physical examination (p less than 0.05), eardrum changes being observed in 34% of the children with recurrent episodes of RTI as preschoolers and in none of the controls (p less than 0.001). Questionnaires answered by parents indicated diseases, particularly cardiovascular diseases, to be significantly more frequent in the families of the children with recurrent RTIs as preschoolers than in those of the controls (p less than 0.01). Parents of the controls were more often satisfied with their own health (p less than 0.05) and reported fewer symptoms of minor illness (p less than 0.05), as compared with parents of the children with recurrent RTIs as preschoolers. Thus, the results of the present study support the idea that children with recurrent bacterial RTIs as preschoolers tend to belong to families with health problems.

Anti-Bacterial Agents↗
PubMedDate not supplied

Nasopharyngeal carriage of bacteria in otitis-prone and non-otitis-prone children in day-care centres.

During a 2-year period nasopharyngeal specimens were taken monthly on scheduled occasions as well as at episodes of acute otitis media (AOM) from a population of children attending day-care centres. The carriage rates of pneumococci, Haemophilus influenzae and Branhamella catarrhalis in 26 otitis-prone (OP) children when asymptomatic and at episodes of AOM were compared with the carriage rates in 36 non-otitis-prone (NOP) children. Pneumococci, H. influenzae and B. catarrhalis were found as frequently in NOP as in asymptomatic OP children. At AOM episodes only B. catarrhalis was found significantly more often than in the scheduled cultures. The frequencies of the six most commonly isolated pneumococcal types/groups (6, 23, 19, 14, 11, 18) were similar in the cultures taken from NOP and OP children on scheduled occasions as well as in cultures taken at AOM episodes. In contrast to the NOP children H. influenzae and B. catarrhalis were isolated less frequently in the 3-4-year-old than in the 2-3-year-old asymptomatic OP children. Our data indicated that the presence of pneumococci, H. influenzae or B. catarrhalis in the nasopharynx does not per se increase the risk for the development of AOM.

Acute Disease↗
PubMedDate not supplied

A longitudinal study of the nasopharyngeal carriage of pneumococci as related to pneumococcal vaccination in children attending day-care centres.

A long-term study of nasopharyngeal carriership in 405 children, aged 6 months to 5 years, attending day-care centres was performed. The effect of pneumococcal vaccination was evaluated in a double-blind investigation where the children received either Pneumovax (a 14-valent pneumococcal vaccine) or saline. Nasopharyngeal cultures were taken monthly by a trained nurse during a 2-year follow-up period. No difference in pneumococcal carriage was found between vaccinees and controls. Pneumococci were found in 31.9% of all cultures. In day-care centres attended by greater than or equal to 45 children the carriage rate of pneumococci was significantly higher than in centres with less than 45 children. Spreading of pneumococci within day-care centres was common but rather short-lived. Children younger than 2 years showed the highest carriage rates. Pneumococci of group 6 were carried most frequently and for longer periods than groups 19 and 23.

Bacterial Vaccines↗