Petteri Carlson

Incidence, treatment and outcome of peripartum sepsis

Background and methods.  Clinical and microbiological features of maternal sepsis in the peripartum period (7 days before to 7 days after delivery) were analyzed to determine possible risk factors, optimal treatment and outcome. In 43 483 deliveries during 1990–98, laboratory‐confirmed bacteremia was found in 41 (5.1%) out of 798 clinically suspected septic infections.

Invasive Group B Streptococcal Infections in Finland: A Population-based Study

We analyzed surveillance data on group B streptococcus (GBS) infection in Finland from 1995 to 2000 and reviewed neonatal cases of early-onset GBS infection in selected hospitals in 1999 to 2000. From 1995 to 2000, 853 cases were reported (annual incidence 2.2–3.0/100,000 population). We found 32–38 neonatal cases of early-onset GBS disease per year (annual incidence 0.6–0.7/1,000 live births). In five hospitals, 35% of 26 neonatal cases of early-onset GBS infection had at least one risk factor: prolonged rupture of membranes, preterm delivery, or intrapartum fever. Five of eight mothers screened for GBS were colonized. In one case, disease developed despite intrapartum chemoprophylaxis. Although the incidence of early-onset GBS disease in Finland is relatively low, some geographic variation exists, and current prevention practices are suboptimal. Establishing national guidelines to prevent perinatal GBS is likely to reduce the incidence of the disease.

Life-Threatening Mycoplasma hominis Mediastinitis

Mycoplasma hominis infections are easily missed because conventional methods for bacterial detection may fail. Here, 8 cases of septic mediastinitis due to M. hominis are reported and reviewed in the context of previously reported cases of mediastinitis, sternum wound infection, pleuritis, or pericarditis caused by M. hominis. All 8 patients had a predisposing initial condition related to poor cardiorespiratory function, aspiration, or complications related to coronary artery surgery or other thoracic surgeries. Mediastinitis was associated with purulent pleural effusion and acute septic symptoms requiring inotropic medication and ventilatory support. Later, the patients had a tendency for indolent chronic courses with pleuritis, pericarditis, or open sternal wounds that lasted for several months. M. hominis infections may also present as mild sternum wound infection or as chronic local pericarditis or pleuritis without septic mediastinitis. Treatment includes surgical drainage and debridement. Antibiotics effective against M. hominis should be considered when treating mediastinitis of unknown etiology.

Stimulation of adenoidal lymphocytes by Alloiococcus otitidis.

Otitis media with effusion (OME) is characterized by persistent effusion in the middle ear cavity and by chronic inflammation in the middle ear mucosa. Alloiococcus otitidis, a gram-positive aerobic bacterium, has been isolated in middle ear effusion, and by means of sensitive polymerase chain reaction detection assays it has been detected in as many as 20% of middle ear aspirates of patients with OME. Because A otitidis may freely interact with leukocytes in the middle ear effusion, it may potentially modulate the inflammatory reaction in OME. To study the nature of these interactions, we applied an in vitro assay in which killed A otitidis bacteria were incubated with peripheral blood and adenoidal mononuclear cells. The expression of the proliferation-associated surface marker CD69 was then measured in B lymphocytes and in CD4+ helper and CD8+ cytotoxic-suppressor T lymphocytes by means of multicolor flow cytometry. Alloiococcus otitidis induced the expression of CD69 in both peripheral blood and adenoidal T and B cells. Among the T cells, the cytotoxic-suppressor T lymphocytes were preferentially activated. It was also tested whether A otitidis would have an effect in another cytotoxic and immunoregulatory system, namely, the induction of natural killer cell activity in peripheral blood mononuclear cells. However, the effect was minimal compared with that of Salmonella minnesota or Staphylococcus aureus. The results show that A otitidis has a unique immunostimulatory capacity in vitro that is mainly confined to CD8+ T lymphocytes.

Arcanobacterium haemolyticum and Streptococcal Pharyngitis

Arcanobacterium haemolyticum was recovered from 0.5% of throat cultures of 3,922 patients seeking medical attention because of sore throat. Most of the patients positive for A. haemolyticum were 15-25 years old, and had fever (80%), lymphadenopathy (67%), pharyngeal exudate (69%) or skin rash (23%). In this age group, 2% of the throat cultures proved positive for A. haemolyticum. All A. haemolyticum strains were susceptible to penicillin, erythromycin, cephalexin and clindamycin, but resistant to trimethoprim/sulphamethoxazole. In half of the patients with A. haemolyticum it was the only bacterial pathogen isolated, while in the remainder, beta-haemolytic streptococci were also detected. As expected, beta-haemolytic streptococci were much more frequent than A. haemolyticum in the throat cultures.

Clinical spectrum of bacteraemic Fusobacterium infections: From septic shock to nosocomial bacteraemia

Abstract Background: Fusobacterium species are anaerobic bacteria that relatively rarely cause sepsis with a variable clinical presentation. Methods: We reviewed the records of 52 consecutive patients who had Fusobacterium bacteraemia over a 10-y period. Results: The clinical pictures could be classified into 4 groups: (1) patients who had Lemierres syndrome with Fusobacterium necrophorum sepsis and internal jugular vein thrombosis, n = 5 (10%); (2) previously healthy patients who had F. necrophorum sepsis without any signs of macroscopic vascular thrombosis (but 5 of them had abscesses), n = 14 (27%); (3) women who had puerperal infections, n = 6 (12%); and (4) patients who were on average older than the patients in the previous groups, who had cardiovascular, pulmonary, neoplastic, or other underlying diseases, n = 27 (52%). Of these latter 27 patients, 23 had nosocomial Fusobacterium nucleatum bacteraemia presenting as a febrile illness associated with chemotherapy or instrumentation. Conclusions: Patients with chronic underlying diseases are more likely to be infected with F. nucleatum than F. necrophorum. F. nucleatum bacteraemia may present as a febrile illness without severe symptoms. F. necrophorum caused sepsis mainly in previously healthy individuals. These infections may be accompanied with a jugular vein thrombosis characteristic of Lemierres syndrome and septic shock. However, F. necrophorum infections present more frequently without any apparent venous thrombosis and may be accompanied by abscesses.

Evaluation of Four Commercial Test Systems for Identification of Actinomyces and Some Closely Related Species

ABSTRACT We evaluated four commercially available kits for rapid identification of Actinomyces and related species. The kits identified correctly 26 to 65% of “classical” Actinomyces strains to the species level and 13 to 49% of newly described Actinomyces strains to the genus level, thus indicating relatively poor applicability and a need to update these kits.

Dysgonomonas hofstadii sp. nov., isolated from a human clinical source

A Gram-negative staining, facultative anaerobic, cocco-bacillus-shaped organism was isolated from a post-operative abdominal wound. Based on morphological and biochemical criteria, strain MX 1040 (=CCUG 54731(T)) was tentatively identified as Bacteroidaceae but did not correspond to any recognized species of this family. Comparative 16S rRNA gene sequencing analysis demonstrated the organism to be related to species of the genus Dysgonomonas, although sequence divergence values of >5% with the other members of this genus demonstrated the organism to represent a novel species. Phylogenetic analysis revealed the novel organism to be most closely related to Dysgonomonas gadei. The major long-chain cellular fatty acids of the novel species consisted of iso-C(14:0), anteiso-C(15:0), C(16:0), and iso-C(16:0). Based on the phenotypic criteria and phylogenetic considerations, it is proposed that strain MX 1040 from a human clinical source represents a new species of the genus Dysgonomonas, as Dysgonomonas hofstadii sp. nov. The type strain of D. hofstadii is CCUG 54731(T) (=CCM 7606(T)).

Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus in systemic and nonoral infections in Finland

The oral cavity is the ecological niche for Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus, but occasionally they cause severe nonoral infections. In this study we present 20 systemic or nonoral infections due to A. actinomycetemcomitans and H. aphrophilus, comprising all isolates of these species forwarded to and stored in Finnish reference laboratories during the years 1988–2000. The time from specimen collection to correct species identification was 9.3 days for A. actinomycetemcomitans and 10.7 days for H. aphrophilus. A. actinomycetemcomitans strains represented serotypes a, b, c, and d. Arbitrarily primed PCR distinguished four A. actinomycetemcomitans and six H. aphrophilus genotypes. Antimicrobial susceptibility testing with benzylpenicillin, amoxicillin, tetracycline, metronidazole, azithromycin, and trovafloxacin showed generally good activities against the present strains, and the susceptibility patterns closely resembled those of oral strains. The prolonged time to recover and identify A. actinomycetemcomitans and H. aphrophilus from systemic and nonoral infections may delay the correct diagnosis of the patient, but the good antimicrobial efficacies of antimicrobial agents against these pathogens give a good prognosis for the patients and advance the treatment of severe infections caused by these fastidious organisms of oral origin.

Arcanobacterium haemolyticum and Streptococcal Pharyngitis in Army Conscripts

Arcanobacterium haemolyticum was found in 1.4% and beta-haemolytic streptococci in 23% of throat cultures from army conscripts with sore throat (n = 498). 38% of the beta-haemolytic streptococci were of group A. Patients culture-positive for A. haemolyticum or beta-haemolytic streptococci had pharyngeal exudate, cervical lymphadenopathy and ear ache significantly more often--but cough less often--than culture-negative patients. The pharyngeal colonization rate of healthy conscripts (n = 232) by A. haemolyticum was 0.4% and by beta-haemolytic streptococci, 6.5%.