Age susceptibility of caesarian derived colostrum deprived pigs to Mycoplasma hyorhinis challenge.

Mycoplasma hyorhinis (MHR) is a major cause of lameness, arthritis, and polyserositis among growing pigs. Reduced performance and culling due to MHR infection result in economic losses in swine production. We have previously developed an MHR challenge model in seven week-old CDCD pigs using cell-associated challenge material which results in both severe pericarditis and lameness. In this study we sequentially challenged CDCD pigs at seven, ten, thirteen, and sixteen weeks of age. Lameness was observed in >60% of the animals in the first three age groups but only 33% in the oldest age group. The number of animals with arthritis declined from 100% at seven weeks, to 56% at ten weeks and approximately 25% at both thirteen and sixteen weeks of age. Pericarditis was observed in 87% of the seven week challenge group, 28% in the ten week challenge group, 8% in the thirteen week challenge group and 4% in the sixteen week challenge group. All challenged groups showed a reduced average daily gain (ADG) compared to their age-matched non-challenged control groups. The largest disparity in ADG (1.2 lbs/day difference) was noted at thirteen weeks of age. Results of this study demonstrate that these animals were susceptible to MHR-associated lameness through sixteen weeks of age while susceptibility to MHR-associated polyserositis appeared to peak at seven weeks of age.

In vivo activity of cefquinome against Riemerella anatipestifer using the pericarditis model in the duck.

Cefquinome is a fourth-generation cephalosporin with broad-spectrum antibacterial activity, including activity against enteric gram-negative bacilli such as Riemerella anatipestifer. The pericarditis model was used to examine the pharmacodynamic characteristics of cefquinome against R. anatipestifer. Serum levels of cefquinome following the administration of different doses were determined by LC-MS/MS. Ducks with ca. 10(6) CFU/mL at the initiation of therapy were treated with cefquinome at doses that ranged from 0.0156 to 2 mg/kg of body weight/day (in 3, 6, 12, or 24 divided doses) for 24 h. The percentage of a 24-h dosing interval that the unbound serum cefquinome concentrations exceeded the MIC (fT > MIC) were the pharmacokinetic (PK)-pharmacodynamic (PD) parameter that best correlated with efficacy (R(2) 86.3% for R. anatipestifer, compared with 58.9% for the area under the concentration-time curve/MIC and 10.6% for peak/MIC). A sigmoid Emax model was used to estimate the magnitudes of the %fT > MIC associated with net bacterial stasis, a 1-log10 CFU reduction from baseline, and a 2-log10 CFU reduction from baseline; the corresponding values were (22.5 ± 1.3) %, (35.2 ± 4.5) %, and (42.4 ± 2.7) %. These data showed that treatment with cefquinome results in marked antibacterial effects in vivo against R. anatipestifer and that the host's immunity may also play a key role in the anti-infective therapy process.

Practice guidelines for the management of patients with histoplasmosis. Infectious Diseases Society of America.

OBJECTIVE: The objective of this guideline is to provide recommendations for treating patients with the more common forms of histoplasmosis. PARTICIPANTS AND CONSENSUS PROCESS: A working group of 8 experts in this field was convened to develop this guideline. The working group developed and refined the guideline through a series of conference calls. OUTCOMES: The goal of treatment is to eradicate the infection when possible, although chronic suppression may be adequate for patients with AIDS and other serious immunosuppressive disorders. Other important outcomes are resolution of clinical abnormalities and prevention of relapse. EVIDENCE: The published literature on the management of histoplasmosis was reviewed. Controlled trials have been conducted that address the treatment of chronic pulmonary and disseminated histoplasmosis, but clinical experience and descriptive studies provide the basis for recommendations for other forms of histoplasmosis. VALUE: Value was assigned on the basis of the strength of the evidence supporting treatment recommendations, with the highest value assigned to controlled trials, according to conventions established for developing practice guidelines. BENEFITS AND COSTS: Certain forms of histoplasmosis cause life-threatening illnesses and result in considerable morbidity, whereas other manifestations cause no symptoms or minor self-limited illnesses. The nonprogressive forms of histoplasmosis, however, may reduce functional capacity, affecting work capacity and quality of life for several months. Treatment is clearly beneficial and cost-effective for patients with progressive forms of histoplasmosis, such as chronic pulmonary or disseminated infection. It remains unknown whether treatment improves the outcome for patients with the self-limited manifestations, since this patient population has not been studied. Other chronic progressive forms of histoplasmosis are not responsive to pharmacologic treatment. TREATMENT OPTIONS: Options for therapy for histoplasmosis include ketoconazole, itraconazole, fluconazole, amphotericin B (Fungizone; Bristol-Meyer Squibb, Princeton, NJ), liposomal amphotericin B (AmBisome; Fujisawa, Deerfield, IL), amphotericin B colloidal suspension (ABCD, or Amphotec; Seques, Menlo Park, CA), and amphotericin B lipid complex (ABLC, or Abelcet; Liposome, Princeton, NJ).

Hemophilus influenzae purulent pericarditis in children: diagnostic and therapeutic considerations.

Purulent pericarditis is an unusual complication of infection in infancy and has been associated with an extremely high mortality rate. Early diagnosis followed by combined antibiotic therapy and surgical drainage of the pericardium has markedly improved survival. Between APril, 1975, and February, 1979, nine patients with purulent pericarditis secondary to Hemophilus influenzae type B were treated at the Oklahoma Children's Memorial Hospital. In every case signs and symptoms of congestive heart failure were present, and a pericardial effusion was demonstrated by echocardiography and confirmed by pericardiocentesis. The organism was identified with countercurrent immunoelectrophoresis and antibiotic sensitivity determined by rapid beta lactamase assay. All patients were treated with a combination of parenteral antibiotics and open surgical drainage of the pericardium. There were no deaths and all patients demonstrated marked improvement following operation. Follow-up echocardiography revealed no evidence of pericardial effusion or signs of constriction in any patient.