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PubMed1996

Community-acquired bacteremia in human immunodeficiency virus-infected children in Harare, Zimbabwe.

BACKGROUND: HIV infection is common in mothers and their children in Zimbabwe, and HIV-infected children are particularly susceptible to bacterial infections. There is little information on the etiology and outcome of HIV-related bacteremia in African children. METHODS: Blood cultures from 309 hospitalized children in Zimbabwe, of whom 168 were diagnosed as having HIV, were examined for pathogens. The association among significant bacteremia, HIV infection and mortality was assessed in these children. RESULTS: The most common isolates were coagulase-negative staphylococci (31 children, 25 clinically significant), Staphylococcus aureus (22 children) and Streptococcus pneumoniae (20 children). Nontyphoidal Salmonella (10 children), Escherichia coli (4 children) and Klebsiella sp. (4 children) were the most frequent Gram-negative bacteria. Two children had Rhodococcus equi pneumonia. HIV-infected children showed increased risk of bacteremia (odds ratio (OR) = 2.68), especially if younger than 18 months of age (OR = 2.94), and high risk of enterobacteremia (OR = 15.76). There was no significant association of bacteremia with nutritional status. Mortality was 17% overall but was higher in HIV-infected children up to 6 months of age (OR = 2.81) and in bacteremic children of any age (OR = 2.03). CONCLUSIONS: Prompt recognition of pathogens and early administration of appropriate antimicrobials is important in reducing the morbidity and mortality associated with bacteremia in HIV-infected children in Africa.

AIDS-Related Opportunistic Infections↗

PubMed2000

Pulmonary infection in human immunodeficiency virus-infected patients in Taiwan.

BACKGROUND: Pulmonary infection is a major cause of morbidity and mortality in human immunodeficiency virus (HIV)-infected patients. METHODS: We conducted a retrospective analysis of the pathogens causing pulmonary infection in 272 HIV-infected patients admitted to a university hospital from January 1993 through December 1998. RESULTS: A total of 158 (58%) patients had pulmonary complications, all but two of whom had acquired immunodeficiency syndrome (AIDS). There were 156 episodes of pulmonary infection, involving 124 patients. The most common pulmonary infection was Pneumocystis carinii pneumonia (PCP): 66 patients had 77 episodes of PCP, all of which occurred in patients with CD4+ lymphocyte counts below 0.2 x 10(9)/L (200/microL). Pulmonary tuberculosis (TB), diagnosed in 47 patients, was the second most common pulmonary infection. Twenty TB patients had open TB. HIV-infected patients who were immigrants from Southeast Asia (9/23, 39%) had a higher risk of developing pulmonary TB than nonimmigrants (38/249, 15%) (p = 0.004). Only one of 17 episodes of community-acquired bacterial pneumonia was caused by Streptococcus pneumoniae. Less common opportunistic pulmonary pathogens included cytomegalovirus (5 cases), Aspergillus species (3), Cryptococcus neoformans (3), Mycobacterium avium complex (2), Penicillium marneffei (1), Nocardia species (1), and Rhodococcus equi (1). CONCLUSIONS: PCP and pulmonary TB are the two leading pulmonary infections in Taiwanese HIV/AIDS patients. These findings should be taken into consideration when developing management strategies and public health policies.

Adolescent↗

PubMed1972

Antigenic type-specificity of swine isolates of Streptococcus equisimilis.

Isolates of a Lancefield Group C organism, Streptococcus equisimilis, of sow reproductive tract and young swine joint origin were found to possess type-specific antigens. Capillary precipitin and immunodiffusion tests, done with acid extracts and cross-absorbed rabbit antisera, revealed four serotypes among 62 of 64 isolates. Extracts of two swine isolates of S. equisimilis and other Lancefield Group C strains including S. equi, S. zooepidemicus and three previously established types of S. equisimilis of human origin did not react with any of the four type-specific sera. Antigens responsible for type-specificity were heat-stable and sensitive to trypsin.

Animals↗

PubMedDate not supplied

[Bacterial infections in patients infected by HIV].

Individuals infected by the human immuno deficiency are more prone to suffering certain bacterial infections in the course of their clinical evolution. The agents involved in these infections are: Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, Salmonella spp and Campylobacter spp, which occasion an increase in morbidity and mortality. With a lower frequency, but with an equal morbidity and mortality, infections have been found caused by Rhodococcus equi, Nocardia spp and Bartonella spp. Even though all of them account for a selective impairment of immunodeficiency in one way or another, their incidence varies. Other factors such as degree of immuno suppression, habits, social and geographic living environment could be important. In general, there is a lack of chemoprophylactic strategies for their prevention. Early diagnosis and correct treatment could have important advantages for the quality of life and survival of these patients

English Abstract↗

PubMed2004

Lancefield group C Streptococcus dysgalactiae infection responsible for fish mortalities in Japan.

A Lancefield serological group C Streptococcus sp. was isolated from cultured amberjack, Seriola dumerili Risso, and yellowtail, Seriola quinqueradiata Temminck and Schlegel, immunized with Lactococcus garvieae commercial vaccines in Japan. The isolated bacteria were Gram-positive cocci, auto-aggregating in saline, morphologically long chains in growth medium, catalase negative and alpha-haemolytic on blood agar. An almost complete gene sequence of the 16S rDNA of two isolates was determined and compared with that of bacterial strains in the database. The isolates were identified as Streptococcus dysgalactiae based on the results of the 16S rDNA sequence, the bacteriological properties and the Lancefield serological grouping. Oligonucleotide primers specifically designed for the 16S-23S rDNA intergenic spacer region of S. dysgalactiae amplified a gene from all the fish isolates, as well as the type strains alpha-haemolytic S. dysgalactiae subsp. dysgalactiae ATCC430738 and beta-haemolytic S. dysgalactiae subsp. equisimilis ATCC35666, but not those of S. equi ATCC33398, Lactococcus garvieae ATCC43921 and L. garvieae KG9408. The severe necrotic lesions of the caudal peduncle seen in experimentally infected fish were similar to those seen in naturally infected fish.

Animals↗

PubMed1993

Bacterial pneumonia in HIV-infected patients.

Individuals infected with the human immunodeficiency virus (HIV) are more susceptible to bacterial infections because of defects in both cellular and humoral immunity. Streptococcus pneumoniae and Haemophilus influenzae are the most common causes of bacterial pneumonia in HIV-infected patients. However, more unusual bacteria can also cause pneumonia. Response to therapy is generally good for infections caused by pyogenic organisms, and complications are relatively few. Unfortunately, infections caused by Rhodococcus equi and Nocardia species are associated with significant morbidity and mortality. Moreover, the duration of therapy is long, and relapes are common. Prevention of bacterial pneumonia is an important part of the care of HIV-infected patients; the 23 valent pneumococcal vaccine is currently recommended for all HIV-infected patients. The role of other preventative measures remains unknown.

Adult↗

PubMed1983

Numerical taxonomy of Streptococcus.

A numerical taxonomic study of strains of Streptococcus, together with representatives of allied genera, showed 28 reasonably distinct phenons. The major areas, with their phenons, were: (a) enterococcal species group (S. faecalis, S. faecium, 'S. avium' and a proposed new species 'S. gallinarum'); (b) paraviridans species group (S. bovis, S. equinus, S. salivarius, 'S. casseliflavus', S. mutans, S. raffinolactis and an unidentified Oral Group I); (c) lactic species group (S. lactis including S. cremoris); (d) thermophilic species group (S. thermophilus); (e) viridans species group (S. mitis, S. sanguis, a proposed new species 'S. oralis' and 'S. milleri'); (f) pyogenic species group (S. agalactiae, S. pyogenes, S. equi, 'S. equisimilis' including 'S. zooepidemicus, and a cluster of Lancefield Group B strains of human origin); (g) parapyogenic species group (S. uberis, 'S. dysgalactiae', and a cluster of strains of Lancefield Groups R, S and T). Species of Aerococcus, Gemella, Leuconostoc and Pediococcus are very closely related to the streptococci.

Enterococcus faecalis↗

PubMed2001

Thermosensitive suicide vectors for gene replacement in Streptococcus suis.

Three thermosensitive (Ts) suicide vectors, pSET4s, pSET5s, and pSET6s, have been constructed for gene replacement in Streptococcus suis. Each vector contains an antibiotic-resistance gene (spc or cat), a Ts replication origin of pWV01 lineage, multiple cloning sites, lacZ', and the ColE1 replication origin of pUC19. These vectors could be propagated at 37 degrees C in Escherichia coli, but their replication was blocked above 37 degrees C in S. suis. Moreover, the thermosensitivity of the replication origin was confirmed in S. equi ssp. equi, S. equi ssp. zooepidemicus, and S. dysgalactiae by using pSET4s. For inactivation of the sly gene, which encodes a thiol-activated hemolysin of S. suis, pSLYK, in which the sly gene was interrupted by the cat gene, was constructed using pSET4s and introduced into S. suis DAT2. After growth at the nonpermissive temperature under the antibiotic pressure, the chromosomal sly gene was replaced with the sly::cat gene of pSLYK by a double-crossover event at a rate of 2.6% among chloramphenicol-resistant cells. Moreover, complementation of the sly gene by use of the previously reported S. suis-E. coli shuttle vector pSET2 was demonstrated. These results indicate that the Ts suicide vectors described here will facilitate the genetic analysis of S. suis and other streptococci of veterinary importance by means of allelic exchange of the genes of interest via homologous recombination.

Base Sequence↗

PubMed1990

Streptococci from the bovine udder in dairy herds in Khartoum Province, Sudan.

Five hundred and seventy-nine milk samples were collected from dairy cows on seven farms in Khartoum North area and one farm in Omdurman and examined by bacteriological cultures for the presence of streptococci. One hundred and ninety-three (33.33%) isolates were recovered and identified on the basis of bacteriological characteristics and biochemical reactions as: S. pyogenes, S. agalactiae, S. dysgalactiae, S. faecalis, S. faecium, S. bovis, S. equi, S. lactis and S. uberis. Fifty-seven isolates representing the preliminary identification were tested by the latex-agglutination test to determine the serological groups. It was found that 39 strains belonged to group B, 3 strains to group C. Four strains gave a weak reaction with group D sera and were identified by biochemical tests as S. uberis. Two isolates could not be identified by the available sera. The isolation of S. uberis, S. bovis, S. equi, S. lactis, S. faecalis, S. faecium and S. pyogenes from cows in the Sudan was reported for the first time.

Animals↗

PubMed2001

Construction and characterization of Streptococcus suis-Escherichia coli shuttle cloning vectors.

pSSU1, a native plasmid of Streptococcus suis DAT1, was used to construct pSET-series shuttle vectors. In addition to the replication function of pSSU1, these vectors contain the multiple cloning sites and lacZ' gene from pUC19, which means that X-gal screening can be used to select recombinants in Escherichia coli. pSET1, pSET2, and pSET3 carry cat, spc, and both of these genes, respectively, as selectable markers. These vectors could be introduced into S. suis, E. coli, Salmonella typhimurium, S. pneumoniae, and S. equi ssp. equi by electrotransformation. The recA gene was cloned from S. suis and sequenced, and this information was used in the construction of a recA mutant of S. suis. Transformation frequencies and/or plasmid stability of all pSET vectors tested were decreased in both S. suis and E. coli recA mutants compared with the parental strains. These results suggested that functional RecA protein improved the maintenance of pSET vectors in both S. suis and E. coli. Moreover, cloning of the functional S. suis recA gene into pSET2 and complementation analysis of the recA mutant were successful in S. suis but not in E. coli. These results showed that pSET vectors are useful tools for cloning and analyzing S. suis genes in S. suis strains directly.

Base Sequence↗

PubMed1983

Variations in the binding of mammalian fibrinogens to streptococci of different animal origin.

Binding of 125I-labelled fibrinogen from humans, bovines, equines, canines and ovines by streptococci of serological groups A, B, C and G was determined quantitatively. All 59 randomly selected streptococcal cultures generally bound more human fibrinogen than the other fibrinogens. Only Sc. dysgalactiae had a higher affinity for bovine fibrinogen. In addition, Sc. dysgalactiae bound distinctly more equine, canine and ovine fibrinogen than the other streptococci. Some cultures of Sc. equi and Sc. zooepidemicus had high binding activities for equine fibrinogen. Low binding capacities were exhibited by B-streptococci, particularly with fibrinogens from horses and dogs.

Animals↗

PubMed1993

Role of beta-hemolytic group C streptococci in pharyngitis: incidence and biochemical characteristics of Streptococcus equisimilis and Streptococcus anginosus in patients and healthy controls.

The biochemical characteristics and the isolation rates of the two Lancefield group C streptococcal species (S. equisimilis and S. anginosus) from patients with pharyngitis and asymptomatic controls were compared. Some 239 strains of beta-hemolytic group C streptococci were isolated from 1,480 patients (209 strains) with pharyngitis and 227 controls (30 strains). A total of 44 strains displayed broad hemolysis, were Voges-Proskauer test negative, and produced glucuronidase. Some 72.7% of these strains also fermented ribose. A second group of 159 strains was Voges-Proskauer test positive and glucuronidase negative; 98.8% also displayed minute hemolysis and only 3.7% fermented ribose. These two groups represent typical large-colony S. equisimilis and small-colony S. anginosus, respectively. A small number of strains (36 in total) exhibited intermediate characteristics; morphologically, all 36 strains resembled S. anginosus, but 6 strains biochemically resembled S. equisimilis. No strains of S. equisimilis fermented sorbitol (unlike S. zooepidemicus) and all fermented trehalose (unlike S. equi). The structural carbohydrate profiles of S. equisimilis and S. anginosus both included galactosamine (consistent with their being group C organisms), but the profiles were not distinguishable. In total, 78.5% of strains from controls and 83.3% of strains from patients were determined to be the species S. anginosus. S. equisimilis was isolated from 3.0% of patients and 2.2% of controls, and S. anginosus was isolated from 11.1% of patients and 11.0% of controls. Thus, S. equisimilis and S. anginosus are both members of the normal flora of asymptomatic individuals. The incidence and biochemical characteristics of these two species are similar in patients who are healthy and those who have disease. However, a companion article provides clinical evidence associating S. equisimilis (but not s. anginosus) with pharyngitis.

Adult↗

PubMed2003

Inter- and intraspecies variations of the 16S-23S rDNA intergenic spacer region of various streptococcal species.

The 16S-23S rDNA intergenic spacer regions (ISR) of different streptococcal species and subspecies were amplified with primers derived from the highly conserved flanking regions of the 16S rRNA and 23S rRNA genes. The single sized amplicons showed a uniform pattern for S. agalactiae, S. dysgalactiae subsp. dysgalactiae (serogroup C), S. dysgalactiae subsp. equisimilis (serogroup G), S. dysgalactiae subsp. dysgalactiae (serogroup L), S. canis, S. phocae, S. uberis, S. parauberis, S. pyogenes and S. equi subsp. equi, respectively. The amplicons of S. equi subsp. zooepidemicus, S. porcinus and S. suis appeared with 3, 5 and 3 different sizes, respectively. ISR of selected strains of each species or subspecies investigated were sequenced and multiple aligned. This allowed a separation of ISR into regions, with 7 regions for S. agalactiae, S. dysgalactiae subsp. dysgalactiae (serogroup C), S. dysgalactiae subsp. equisimilis (serogroup G), S. dysgalactiae subsp. dysgalactiae (serogroup L), S. canis, S. phocae, S. pyogenes and S. suis, 8 regions for S. uberis and S. parauberis and mostly 9 regions for S. equi subsp. equi, S. equi subsp. zooepidemicus and S. porcinus. Region 4, encoding the transfer RNA for alanine (tRNA(Ala)), was present and identical for all isolates investigated. The size and sequence of ISR appears to be a unique marker for streptococci of various species and subspecies and could be used for bacterial identification. In addition the size and sequence variations of ISR of S. equi subsp. zooepidemicus, S. porcinus and S. suis allows a molecular typing of isolates of these species possibly useful in epidemiological aspects.

DNA, Bacterial↗

PubMed2000

[Sensitivity of bovine and equine streptococci to beta-lactam antibiotics (benzylpenicillin, ampicillin, oxacillin, cefotaxime) in the agar diffusion and E-test].

368 streptococcal strains from udder secretions of cattle (Sc. agalactiae, Sc. dysgalactiae, Sc. uberis) and 191 streptococcal isolates from horse specimens (Sc. equi ssp. zooepidemicus, Sc. equi ssp. equi) originating from different agricultural regions in Germany (Lower Saxony, in particular the region of Weser-Ems, Bavaria, Altmark) were investigated for their sensitivity to 4 beta-lactam antibiotics (benzylpenicillin, ampicillin, oxacillin, cefotaxime). Two different test methods were applied: the agar diffusion test for determination of the diameter of the zone of inhibition and the E-test for determination of the minimal inhibitory concentration (MIC). According to the evaluation code of DIN 58,940, 98% to 100% of the isolates from the cow udder as well as of the Streptococcus strains from horses were sensitive to the four antibiotics tested. Only Sc. uberis was less sensitive to benzylpenicillin (79.7%) and Oxacillin (83.2%). The strains from different agricultural regions did not differ from each other concerning their sensitivity to beta-lactams. The results of the two methods of sensitivity testing were in satisfactory agreement: Compared to the MIC reference values, misclassifications occurred in the agar diffusion test only at an error rate of between 1.62% (for ampicillin) and 5.21% (for benzylpenicillin).

Ampicillin↗

PubMed2001

Comparative genomics reveals close genetic relationships between phages from dairy bacteria and pathogenic Streptococci: evolutionary implications for prophage-host interactions.

The genome of the highly pathogenic M1 serotype Streptococcus pyogenes isolate SF370 contains eight prophage elements. Only prophage SF370.1 could be induced by mitomycin C treatment. Prophage SF370.3 showed a 33.5-kb-long genome that closely resembled the genome organization of the cos-site temperate Siphovirus r1t infecting the dairy bacterium Lactococcus lactis. The two-phage genomes shared between 60 and 70% nucleotide sequence identity over the DNA packaging, head and tail genes. Analysis of the SF370.3 genome revealed mutations in the replisome organizer gene that may prevent the induction of the prophage. The mutated phage replication gene was closely related to a virulence marker identified in recently emerged M3 serotype S. pyogenes strains in Japan. This observation suggests that prophage genes confer selective advantage to the lysogenic host. SF370.3 encodes a hyaluronidase and a DNase that may facilitate the spreading of S. pyogenes through tissue planes of its human host. Prophage SF370.2 showed a 43-kb-long genome that closely resembled the genome organization of pac-site temperate Siphoviridae infecting the dairy bacteria S. thermophilus and L. lactis. Over part of the structural genes, the similarity between SF370.2 and S. thermophilus phage O1205 extended to the nucleotide sequence level. SF370.2 showed two probable inactivating mutations: one in the replisome organizer gene and another in the gene encoding the portal protein. Prophage SF370.2 also encodes a hyaluronidase and in addition two very likely virulence factors: prophage-encoded toxins acting as superantigens that may contribute to the immune deregulation observed during invasive streptococcal infections. The superantigens are encoded between the phage lysin and the right attachment site of the prophage genome. The genes were nearly sequence identical with a DNA segment in S. equi, suggesting horizontal gene transfer. The trend for prophage genome inactivation was even more evident for the remaining five prophage sequences that showed massive losses of prophage DNA. In these prophage remnants only 13-0.3 kb of putative prophage DNA was detected. We discuss the genomics data from S. pyogenes strain SF370 within the framework of Darwinian coevolution of prophages and lysogenic bacteria and suggest elements of genetic cooperation and elements of an arms race in this host-parasite relationship.

Bacteriophages↗

PubMed1977

[The sensitivity of various in-vitro-test systems in biological testing of materials].

In the present paper the biological activity of methylmethacrylate Monomer and di-methylparatoluidin on stationary, cell-proliferating and bacterial cultures is examined. The equi-toxic concentrations were lower in cell culture systems than in stationary cell suspensions or bacterial cultures. Accordingly biological reaction appears to depend on the effective concentration of the toxic substance as well as on the specific sensitivity of the test system. There is no correlation between the sensitivity of cellular and of bacterial test systems.

Animals↗

PubMed1993

The protective M proteins of the equine group C streptococci.

The group C streptococci are the most commonly isolated bacteria from disease states in the horse. Important virulence factors of S. equi and S. zooepidemicus are the hyaluronic acid capsule and the antiphagocytic fibrillar M protein located on the surface of the cell wall and extending into and through the capsule. The hyaluronic acid capsule is non-antigenic and so is not involved in protective immunity. The M protein, a superantigen, elicits very strong B and T cell responses that may result in protective immunity mediated by opsonic antibodies in plasma and by locally synthesized IgG and IgA on the pharyngeal mucosa. However, vaccines based on acid or mutanolysin extracted M protein do not confer a high level of protection against field exposure. Protective antibodies to S. equi or S. zooepidemicus can in part be assayed by the bactericidal test that measures opsonization for equine neutrophils. A mouse-challenge model has also been used to test immunizing potency of streptococcal extracts and in a passive protection test for protective antibody. There is as yet no means of distinguishing protective opsonic or mucosal antibodies from other antibodies produced against the many epitopes on the M molecule.

Animals↗

PubMed1987

Heterogeneity of fibronectin reactivity among streptococci as revealed by binding of fibronectin fragments.

Streptococci belonging to serological groups A, B, C, G, L and U were studied for their interaction with 125I-labelled fibronectin and its fragments. Fibronectin purified from humans plasma by affinity chromatography on gelatin-agarose and heparin-agarose was cleaved by thrombin into a 29,000 Dalton and a 210,000 Dalton fragments. Terminal analysis of purified fragments indicated that 29,000 fragment was from amino-terminal and 210,000 fragment from carboxyl-terminal domain of fibronectin. Binding of fibronectin was observed in all streptococci except those of group B. Streptococci of groups A, G, L, U and S. equisimilis reacted only with 29,000 Dalton fragment whereas S. dysgalactiae, S. zooepidermicus and S. equi reacted only with 210,000 Dalton fragment. The streptococcal binding sites for these two fragments were distinct from each other. Fibrinogen blocked the binding of 210,000 Dalton fragment but not of 29,000 Dalton fragment. Trypsinization of streptococci did not affect their binding sites for 210,000 Dalton fragment but destroyed those for 29,000 Dalton fragment. The results indicate that the streptococci of group A and G as well as S. equisimilis which are mainly pathogenic in humans bind amino-terminal fragment of fibronectin. This may facilitate the adherence of these pathogens. On the other hand, the streptococci isolated from animal infections had different binding sites recognized only by carboxyl-terminal part of fibronectin.

Binding Sites↗