Isolation of Abiotrophia spp. with Staphylococcus aureus in a case of mastitis in a cow.
Isolation of Streptococcus suis from a young wild boar C treptococcus suis is an important pathogen of pigs, which has also been recognized as a zoonotic agent (1). Streptococcus suis has been associated with sporadic infections in a variety of mammalian species, such as, cattle, bison, horses, sheep, goats, dogs, and cats (2). It has recently been isolated from psittacine birds, zebrafinches, canaries, bullfinches, and a duck (2). A 20-day-old, wild boar from a 30-sow herd was submitted to the Faculte de medecine vet6rinaire of the Universit6 de Montr6al with signs of pneumonia and diarrhea. The animal was alert and did not show any neurological signs. The boar was euthanized; at necropsy, the cranial lobes of the lung, particularly on the the right side, were firm textured. The caudal lobes of the lung were not affected. There was no evidence of arthritis. Microscopic examination of the lung revealed suppurative bronchopneumonia with hemorrhagic foci and fibrinous exudation. A moderate number of coccidia were seen in sections of the small intestine. Bacteriological cultures of lungs yielded Streptococcus suis capsular type 2 colonies in large numbers, as well as a comparable number of colonies of Escherichia coli. The E. coli isolated from the intestines did not possess any of the enteropathogenicity virulence factors, and tests for rotavirus and coronavirus were negative. A total of 3 litters in this herd showed signs of infection with Streptococcus suis. Marked clinical improvement was noted after pigs from these litters were injected with 300,000 units of procaine penicillin G. The origin of the infection was not determined, but there is speculation that it spread from a swine herd on the same farm.
C-REACTIVE PROTEIN IN CHILDHOOD NON-TYPHI SALMONELLA GASTROENTERITIS WITH AND WITHOUT BACTEREMIA
Non-typhi Salmonella species are the most common bacterial pathogens of gastroenteritis in Taiwan. Except in immunocompromised patients most Salmonella infections are limited to the gastrointestinal tract, and it generally is agreed that Salmonella gastroenteritis should not be treated with antibiotics because these agents do not shorten the course of illness; rather, they lengthen the period of asymptomatic excretion. 3 In children with secondary bacteremia and/or extraintestinal foci, an appropriate antibiotic is usually needed. No simple clinical data or laboratory tests allows for the reliable detection of Salmonella gastroenteritis with secondary bacteremia rapidly. Serum C-reactive protein (CRP) is an acute phase reactant that increases in the presence on inflammation caused by infection and/or tissue injury. Usually the greater the tissue destruction, the higher is the CRP value. Previous reports 12 either indicated that the determination of CRP may be a useful tool to predict bacterial gastroenteritis or suggested that a low CRP (,2 mg/dl), a very good negative predictive value, might allow clinicians to reliably exclude Salmonella as a cause of gastroenteritis. In this study we tried to evaluate whether quantitative serum CRP could differentiate Salmonella gastroenteritis with secondary bacteremia from isolated Salmonella gastroenteritis. Materials and methods. All children with positive stool culture for non-typhi Salmonella who were admitted to Chang Gung Children’s Hospital between January, 1996, and June, 1997, were included in this retrospective study. At the time of hospitalization, initial laboratory data obtained included blood culture for bacteria, complete blood cell count and serum CRP. During this period CRP concentration was measured quantitatively by a fluorescent polarization immunoassay and a CRP value ,5 mg/l was considered normal. Demographic data, clinical manifestations and laboratory data were recorded and analyzed. The patients were categorized into two groups: A, isolated Salmonella gastroenteritis; and B, complicated with secondary bacteremia. Statistical analysis of continuous variables was done using the independent samples t test, and categorical variables were subjected to chi square analysis and the Fisher’s exact test with standard computer software (SPSS 7.0 for Windows). For all analyses we assumed a statistical significance of P , 0.05. Results. During this period 268 children 16 days to 14 years old with bacteriologically confirmed non-typhi Salmonella gastroenteritis were included in the study. There were 246 (91.8%) children with isolated Salmonella gastroenteritis (Group A) and 22 (8.2%) complicated with secondary bacteremia (Group B). Two hundred twenty-seven (84.7%) patients were younger than 2 years of age. There were 160 male children and 108 female children. Stool specimens from 246 cases were also examined for rotavirus, and a positive result was found in 7 cases. The patients did not have immunocompromising conditions, malignancy or extraintestinal complications such as meningitis or osteomyelitis. There was no death. The mean and median ages of children in Group B were 12.9 and 10.5 months, respectively, which were not significantly different from those (14.7 and 11.0 months, respectively) of patients in Group A (P 5 0.577). The frequency of secondary bacteremia in these children by various age groups is shown in Table 1. No significant differences were found between the children younger than 3 months or 1 year of age and those who were older. The relationship between serogroup and secondary bacteremia is shown in Table 2. Serogroup D strains were associated with bloodstream invasion (P 5 0.020). Table 3 illustrates the CRP, white blood cell counts and band forms in children in both groups. Of the 246 patients in Group A, 14 (5.7%) children had a CRP value ,5 mg/l, 91 (37%) children 5 to 50 mg/l, 56 (22.8%) children 51 to 100 mg/l and 85 (34.6%) children .100 mg/l, with a mean of 83.5 mg/l. Of the 22 children in Group B 1 (4.5%) child had a CRP concentration ,5 mg/l, 12 (54.5.0%) children 5 to 50 mg/l, 7 (31.8%) children 51 to 100 mg/l and 2 (9.0%) children .100 mg/l, with a mean of 65.6 mg/l. There was a considerable overlap between the 2 patient groups and no significant difference (P 5 0.361) was found. Forty-three (17.6%) of 246 children in Group A had a white blood cell count of .15 000 cells/mm, and so did 6 (22.7%) of 22 children in Group B. Band form cells were higher in Group B, but 10 (45.5%) patients in this group had no band form cells, whereas 55 (22.4%) patients in Group A had no band form cells. Discussion. Results from this study indicated that serum CRP values were elevated in most children with Salmonella gastroenteritis and that there was no significant difference between the children with and without secondary bacteremia. We had assumed that the CRP might be higher in children with secondary bacteremia. The CRP remains elevated with ongoing inflammation and tissue destruction, but with resolution it declines rapidly, because of a relatively short half-life of 4 to 7 h. 13, 14 The timing of measurement of CRP can affect the results. In this retrospective study the timing of CRP measurement was at the time of hospitalization, which was not the same time for disease process in each case. This bias may influence the interpretation of the results. The reported frequency of bacteremia in children with non-typhi Salmonella gastroenteritis is variable. 15, 16 In this study the frequency of secondary bacteremia was 8.2%, which was similar to that of previous reports from Taiwan. 18 In general a higher incidence of bacteremia has been found in children younger than 1 year of age with a peak in 0to 2-month age group. 5, 16 However, the present study indicated that no significant difference in terms of secondary bacteremia was found between the children younger than 3 months or 1 year of age and those older. In previous reports the Salmonella serotype was highly related to the rate of bacteremia. 17, 18 In this study serogroup D was the most invasive serogroup in causing secondary bacteremia. These results support the findings of a study by Huang et al. from Taiwan. In their study a genotype of Salmonella dublin was shown to be more invasive than the others. However, in our previous study Salmonella typhimurium and Salmonella schwarzengrund (serogroup B) were the other two invasive serotypes, in addition to S. dublin (serogroup D). In summary, even though CRP determination may be
Antimicrobial therapy of vitamin B6-dependent streptococcal endocarditis.
Vitamin B6-dependent viridans streptococci were isolated from two patients with microbial endocarditis. Because of their unique requirement for pyridoxal hydrochloride, these organisms did not grow normally in the media usually used in diagnostic laboratories. When tested in supplemented media, both strains were resistant to penicillin G and relatively sensitive to streptomycin. Penicillin-streptomycin synergy was demonstrated in vitro as well as in experimental endocarditis. These laboratory findings confirmed the clinical observations in these two patients that penicillin-streptomycin therapy should be used in vitamin B6-dependent streptococcal endocarditis. Nutritionally varient streptococci may be important pathogens in microbial endocarditis and must be considered in patients with suggestive clinical findings but negative blood cultures.