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Results for “beta-haemolytic streptococci”

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At least 19 recordsLinked to original sources
PubMed1978

Rapid identification of group A, B, C and G beta-haemolytic Streptococci by a modification of the co-agglutination technique. Comparison of results obtained by co-agglutination, fluorescent antibody test, counterimmunoelectrophoresis, and precipitin technique.

A rapid modification of the co-agglutination (COA) technique for grouping A, B, C and G beta-haemolytic streptococci was developed. The results are obtained within three hours after inoculation from primary plates of 0.5 ml broth. This method was compared to the fluorescent antibody test (FA) and counterimmunoelectrophoresis (CIE), two other rapid methods available for serological grouping of streptococci. Of 71 recently isolated streptococcal strains from clinical sources, 70 were correctly grouped in COA, 63 in FA and 68 in CIE. With commercial reagents COA compared favourably in accuracy to the other methods and can be recommended for routine serological grouping of beta-haemolytic streptococci in the clinical laboratory.

Agglutination Tests↗
PubMed1979

"Fingerprinting" beta-haemolytic streptococci by their production of and sensitivity to bacteriocine-like inhibitors.

A scheme for the "fingerprinting" of streptococci according to their production of (P typing) and sensitivity to (S typing) bacteriocine-like inhibitory substances has been developed. P typing of 450 beta-haemolytic streptococci by their action on a set of nine standard indicator strains revealed that 80% of strains produced one or more detectable inhibitors, and that 17 different P types could be recognised. Production of some inhibitors seemed to be a property of strains of a particular serological group or type. Bacteriocine-like substances were produced by streptococci of serological groups, A, B, C, D, E, F and G. Nine strains were selected as standard producers for S typing. These strains differed in their spectra of inhibition, but all seemed to be active only against gram-positive bacteria. One producer, a group-F streptococcus, specifically inhibited group-A streptococci. The conditions of incubation were critical for demonstration of inhibitor production. A requirement for blood and for incubation at 32 degrees C were important factors. None of the inhibitors was induced by ultraviolet irradiation. The observed inhibitory effects were not attributable to either hydrogen peroxide or low pH, but to the production of a variety of substances having diverse physicochemical properties and production requirements. Most of the inhibitors do not seem to be produced in liquid media. The "fingerprinting" procedure is simple and inexpensive, and provides a reliable means of subdividing streptococcal strains that may find application as a supplement to the existing serological typing schemes.

Bacteriocins↗
PubMed1977

Serological grouping of streptococci by a slide coagglutination method.

A new method for the serological grouping of streptococci by coagglutination with specific antibodies absorbed to protein A-containing staphylococci has been assessed. A total of 242 strains of streptococci, including beta-haemolytic streptococci of groups A, B, C, F, and G, Streptococcus pneumoniae and Strep. faecalis were studied. All streptococci of groups A, B, C, and G, groupable by standard methods, were correctly grouped by coagglutination, although 7-3% showed varying degrees of cross-agglutination. Two beta-haemolytic strains of Strep. faecalis produced coagglutination with group C streptococcal reagent. The method appears to be quick, accurate, reproducible, and simple to perform.

Agglutination Tests↗
PubMed2026

Emerging trends in invasive Streptococcus dysgalactiae subsp. equisimilis infections in Denmark, 2014 to 2024: a nationwide genomic and registry-based study.

BACKGROUNDIncreasing incidence rates of invasive Streptococcus dysgalactiae subspecies equisimilis (iSDSE) have been detected worldwide.AIMWe aimed to investigate iSDSE infection incidence rates in Denmark during 2014-2024, and characterise the genomic population structure of a subset of iSDSE isolates and their antimicrobial resistance (AMR).METHODSUsing national register data, we estimated overall and sex-/age-stratified iSDSE incidences during 2014-2024, by retrospectively identifying cases of invasive infections with group C and G streptococci or S. dysgalactiae (including specified as subspecies equisimilis). From the voluntary national beta-haemolytic streptococci laboratory surveillance system, whole-genome-sequenced isolates from August 2020-September 2022 were used to investigate the iSDSE genomic population structure. Susceptibility to penicillin, erythromycin and clindamycin was determined and AMR genes identified.RESULTSDuring 2014-2024, iSDSE incidence rates increased significantly (linear trend analysis p&#x2009;<&#x2009;0.001) with mean annual incidence ranging between 10.3 and 16.4 per 100,000, peaking in 2023. Incidence was higher in males, increasing with older age. Nearly 75% of the&#x2009;1,223 iSDSE isolates belonged to four of 14 genetic clusters. Sequence types (STs) ST20 and ST17 were most prevalent, while emm-type stG62647, a variant associated internationally with higher virulence, dominated. All isolates were phenotypically susceptible to penicillin but approximately 10% were respectively erythromycin and clindamycin resistant. High erythromycin resistance prevalence (57%;&#x2009;39/68), coinciding with gene ermA, occurred in one genetic cluster.CONCLUSIONThe findings illustrate the need for national registry-based surveillance to detect epidemiological changes and potential outbreaks. Further, continuous genomic surveillance can monitor the occurrence and expansion of genetic clades and AMR genes.

Denmark↗
PubMed1978

[Microbiological studies on bacterial spectra of milk samples from healthy udder quarters and from those with increased cell counts and/or conductivity values].

The germ levels of 2,182 milk samples obtained from udder quarters with subclinical mastitis were compared to milk sampled from 2,061 udder quarters with physiological cell counts or conductivity values. Three cattle herds were involved in the test programme. No germ growth was established from 9.5 per cent of all samples taken from udder quarters with increased cell counts and conductivities and from 4.1 per cent of those samples taken from intact udder quarters. Samples taken from udder quarters with subclinical mastitis exhibited the following rises in bacteria, as compared to samples from intact quarters: staphylococci by 3.1 per cent, staphylocci in germ mixtures by 3.0 per cent, CAMP-positive streptococci by 2.2 per cent, alpha-haemolytic CAMP-negative streptococci by 0.8 per cent, anhaemolytic streptococci in germ mixtures by 0.4 per cent, beta-haemolytic streptococci by 0.5 per cent, and Pseudomonas aeruginosa by 1.4 per cent. Other germ species and mixtures exhibited declining trends along with growing subclinical affection of udder quarters. All findings so far obtained in the presence of subclinical mastitis are likely to suggest that 11.4 per cent of detected bacteria were of pathogenicity to udders. However, attempts to localise those 11.4 per cent were unsuccessful, since no significant difference could be calculated by comparison of intact with affected udder quarters. Reference is made in the discussion to primary and secondary germ levels of milk samples and their relevance to the problem and its elucidation.

Animals↗
PubMed1978

Group B beta haemolytic streptococci in the female genital tract: a study of four clinic populations.

The carrier rate of group B beta-haemolytic streptococci (GBS) was assessed in pregnant and non-pregnant women attending four clinics. Multiple sites were sampled and standard methods were used to isolate GBS. Colonization rates were highest in patients attending a venereal disease clinic but were not associated with other sexually transmitted diseases. Higher colonization rates were detected when multiple sites were sampled. Serotypes II and III occurred most frequently.

Adolescent↗
PubMed1977

Further studies on the reliability of the bacitracin inhibition test for the presumptive identification of Lancefield group A streptococci.

The reliability of the bacitracin inhibition test to differentiate between 125 Lancefield group A and 122 non-group A beta-haemolytic streptococci was studied. Bacitracin discs containing 0-02, 0-04, or 0-1 international units and the conditions recommended by both the Association of Clinical Pathologists and the Federal Drug Administration for routine sensitivity testing were used. The results suggest that the presence or absence of a zone of inhibition around a 0-04 unit disc can be used routinely for the presumptive identification of group A streptococci and that a specific zone size can be used for reading the test only with a 0-1 unit disc.

Bacitracin↗
PubMed1978

Lactostrepcins--acid bacteriocins produced by lactic streptococci.

All 47 non-nisin producing strains of Streptococcus lactis and 12/13 strains of Str. lactis subsp. diacetylactis examined produced bacteriocins, for which the term lactostrepcins is suggested. Seven strains of Str. cremoris examined produced no bacteriocins active against 3 lactic streptococci strains used as indicators. The strains examined were divided into 3 groups: I, those producing lactostrepcins active against only one streptomycin resistant mutant of Str. lactis 60 indicator strain; II, those producing lactostrepcins active against all 3 indicator strains; III, those not producing lactostrepcins active against the indicator strains employed. The lactostrepcins were sensitive to various proteolytic enzymes and to phospholipase D, but retained full or partial activity after dialysis. Most of the bacteriocins studied were fully active only within the pH range 4.2--5.0 and were reversibly inactivated at pH 7.0 or 8.0. Results suggested occurrence of 4 different lactostrepcins. The lactostrepcins produced by all group I strains were the same, but there were differences among the lactostrepcins produced by group II strains. Lactostrepcins killed some beta-haemolytic streptococci and some strains of Lactobacillus helveticus. One of the lactostrepcins was also active against certain Leuconostoc strains, but not against other Leuconostoc strains, nor against L. helveticus or other Gram-positive bacteria.

Bacteriocins↗
PubMed1979

Bacteriological quality control in human milk-banking.

The bacteriological quality of pooled human milk donated to the Oxford milk bank was analysed and the effects on bacteriology of sterilisation of the milk-collecting vessels in the home with hypochlorite solution and of Holder pasteurisation in a purpose-built human-milk pasteuriser were studied. Collecting milk in hypochlorite-sterilised vessels resulted in a significantly lower bacterial count of both pathogens and species of unlikely pathogenicity before pasteurisation and significantly increased the chance of pasteurisation giving a sterile product. Potentially pathogenic organisms grown in untreated milk were Escherichia coli, Staphylococcus aureus, and group B beta-haemolytic streptococci. Seven species of organisms of unlikely pathogenicity were also identified. Pasteurisation eliminated all potential pathogens from milk but did not reliably remove any of the species of unlikely pathogens. Banked human milk may be contaminated with bacteria which are known to be capable of producing lipases, proteases, and decarboxylases. Accurate pasteurisation, together with attention to the sterility of the collecting vessels, results in a bacteriologically safe product that retains many of the protective properties of raw milk.

Disinfection↗
PubMed1978

An epidemiological study of rheumatic fever and rheumatic heart disease in Lagos.

In Lagos 12 755 schoolchildren aged between six and 12 years were screened for evidence of rheumatic heart disease and showed a prevalence rate of 0.03%. Group C (27.7%) and group G (47.3%) predominated in the throat and in cases of pharyngitis, while group A predominated on the skin. Two hundred and sixty-six cases of pharyngitis were recorded, 70 (26.4%) were positive for beta-haemolytic streptococci. Half of the cases of streptococci while 28.2% and 21.1% were caused by groups C and G respectively. A diversity of serotypes of group A streptococci, which included types 49 and 55, and C and G streptococci were isolated from impetiginous skin lesions. The main point of interest is the association of group C and G streptococci with sore throat and skin infections. The pathogenicity of C and G in such circumstances merits further investigation. The present study also showed that prophylactic benzathine penicillin (Penadur) given to patients with rheumatic heart disease or rheumatic fever had been effective with no recurrent attack of acute rheumatic fever.

Child↗
PubMed1978

Clinical experience with cefadroxil in upper and lower respiratory tract infections.

Cefadroxil is a new semisynthetic oral cephalosporin with a broad spectrum of activity against both Gram-positive and Gram-negative organisms. Absorption of cefadroxil is unaffected by food, its serum levels are prolonged and it is excreted in the urine at a relatively slow rate compared to cephalexin. In the treatment of 108 patient with upper or lower respiratory tract infections, cefadroxil effected 93% complete cures. Fifty-five of the patients had upper respiratory tract infections and fifty-three had lower respiratory tract infections; among them cefadroxil acheived clinical success rates of 100% and 96%, respectively. Cefadroxil was clinically successful in eight (89%) out of nine patients whose infections were caused by mixed aetiologies. The principal causative agents were Staphylococcus aureus, beta-haemolytic streptococci, Streptococcus pneumoniae and Klebsiella pneumoniae. Overall bacterial eradication produced by cefadroxil was 112 (91%) of 123 organisms isolated from 108 patients. Reports of mild and transient side-effects in only 3.7% of the patients showed that the drug was well tolerated.

Adolescent↗
PubMed1978

An overview of results of world-wide clinical trials with cefadroxil.

Céfadroxil, a new semisynthetic oral cephalosporin, is absorbed similarly by fasted and non-fasted subjects, produces sustained serum levels and is eliminated at a relatively slow rate. These pharmacokinetic properties permit less frequent and more convenient dosage scheduling than cephalexin and cephradine and consequently greater patient compliance. Cefadroxil was evaluated for safety in 1051 patients and for efficacy in 1030 patients. Overall it achieved a 91.8% rate of clinical success resulting from 881 complete cures and sixty-five clinical cures. Among 363 patients with respiratory tract infections and 471 patients with genito-urinary tract infections, cefadroxil treatment produced 97.5% and 84.5% clinical success, respectively. In the remaining infectious diseases treated, cefadroxil therapy resulted in 99.0% clinical success. Cefadroxil eradicated 87% of 1110 pathogens isolated, among which the most predominant pathogens were Staphylococcus aureus, beta-haemolytic streptococci, Streptococcus pneumoniae, Escherichia coli and Proteus mirabilis. Drug-related side-effects were reported in 7.2% of the patients.

Adolescent↗
PubMed1977

Group B streptococcal infection in neonates.

A study of 866 vaginal swabs from non-pregnant women showed that 167 (19.3%) contained Group B beta-haemolytic streptococci, with a predominance of Types 3 (31.4%) and Ib (25.2%). The incidence of severe neonatal infections due to Group B streptococci during a 3 1/2 year period at The Prince of Wales Hospital was examined, and a study was made of the distribution of serotypes and associated clinical features (including prematurity and abnormal deliveries) in 16 neonates with septicaemia and/or meningitis admitted to the Royal Alexandra Hospital for Children, and the Paediatric Department of The Prince of Wales Hospital. From this study it was concluded that prophylactic antibiotic therapy should be administered to neonates with evidence of Group B streptococcal colonization of the throat, umbilicus, or gut, when there is also evidence of prematurity, prolonged interval between membrane rupture and delivery, or other associated obstetric complications.

Adolescent↗
PubMed1977

[Relationships between Streptococcus pyogenes T4-antigens and haptoglobin types (author's transl)].

Some strains of beta-haemolytic streptococci were agglutinated with high titers (1:200-1:6400) by human sera of the haptoglobin types 2-2 and 2-1. No agglutination or with low titers (up to 1:20) was observed with sera of the haptoglobin type 1-1. This reactivity depends from the contents of Streptococcus pyogenes T-antigens of the T-complex 4,24... This T4-antigen is present in group A streptococci (Strep. pyogenes) of the types 4, 24, 26, 28, 29, 46, 48 and 60 but it may be present also in some strains of streptococcal groups C and G. During a 10-year period we isolated 12 strains of Strep. equisimilis (group C) carrying the T-4 antigen (1.6%) and 50 group-G streptococci with T-4 antigen (6.4%) of all group G streptococci). These strains were agglutinated without an exception with high titers by Hp 2-2 and Hp 2-1 sera but not by sera of the haptoglobin type 1-1. The same particuliarity was shown by Streptococcus pyogenes types of the T-complex 4, 24... One strain of type 26 (BC 179) has no T antigen and therefore it was not agglutinated in the above mentioned manner. The phenomenon depends from the medium; it occurs after cultivation of the streptococci in Pope broth or in meat-infusion with glucose but not or only reduced in beef heart-proteose-medium. The agglutination reaction is caused by the haptoglobin but not by agglutinins against the T4-antigens.

Agglutination↗
PubMed1979

[Persistency and resistance of streptococci isolated from periodontal pockets].

Intradermal injection of cell walls or cell wall constituents (Peptidoglycane) of Streptococcus sanguis II in experimental animals caused a similarly severe inflammatory reaction as with Streptococcus A. The three "viridans" species of streptococci proved to be resistant to complement (active serum) as well as to lysozyme and were superior to Streptococcus A in their capacity for resistance to another type of muralytic enzyme isolated from Streptomyces albus. The new acylureido penicillins (Mezlocillin, Azlocillin) had an almost equally inhibitory effect on the growth of the various species of bacteria. The "viridans" and beta-haemolytic types of streptococci which induce a chemotactic reaction in vitro were about equally rapidly and effectively killed in the phagocytes (granulocytes, monocytes) isolated from a patient.

Cell Wall↗
PubMed1978

Rheumatic fever and streptococci: the Wairoa College study.

The decline in incidence of rheumatic fever seen in many countries is not evident in New Zealand. Wairoa county has the highest hospital admission rate within New Zealand, 232 per 100 000 per year, five times the national average, 43 per 100 000. Studies in Wairoa included a cross-sectional survey of the local secondary school. Throat swabbing yielded 13.6% of subjects positive for beta-haemolytic streptococcus group A. Boys had a higher rate than girls, and girls aged 14 and over had a lower rate than younger girls. Discriminant analysis failed to identify ethnic, social or geographic factors as contributing to positivity. Sibling concordance was not significant. ASO titres were high in comparison with another New Zealand study (Rotorua Lakes). There was an association between high ASO titre and throat swab positive for group A and group C streptococci. The prevalence of definite rheumatic fever and rheumatic heart disease was established as 11/715 (1.5%). A wide range of residential geographic, climatic and socioeconomic factors failed to discriminate between cases and noncases. Ethnicity alone was a significant discriminator, the cases being more Maori than noncases.

Adolescent↗