An 81-year-old man with no relevant medical history was admitted in January 2003 for respiratory infection.
He had been living in rural areas for 26 years where he worked as a farmer.
In the last eight days prior to admission, the patient developed dyspnea and cough.
Physical examination revealed Ta ax. of 38.5 oC, slightly tachypnea and decreased level of consciousness.
Complementary laboratory tests: leukocytosis (12.2 x 109/l; 86% neutrophils and 3% cavitated).
Arterial gas: hypoxemia and hypocapnia (pO2: 59 mmHg; pCO2: 25.7 mmHg).
Chest X-ray: presence of pleural calcifications without other relevant findings.
Initially, empirical antibiotic treatment consisted of cefoxime: 6 g/day.
After six days of treatment, the patient showed no improvement and blood samples taken on the day of admission showed the growth of ARE pyogenes resistant to trimethoprim-metaloxazole.
The chest CT scan showed the presence of bilateral pleural effusion and basal pulmonary infiltrates in addition to the pleural calcifications initially found in the X-ray.
The throat culture was positive for Candida tropicalis and coagulase-negative Staphilococcus.
No other relevant data were found in other complementary examinations such as abdominal ultrasound, brain CT and bronchoscopy.
Initial antibiotic treatment was changed to cefoxime 6 grs./day and clarithromycin 1 g/day, achieving complete recovery 8 days after the new treatment.
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HAZGES MICROBIGICOS
On the third day, isolation bacilli from blood samples, all anaerobic blood cultures (BacT/Alert blood culture system; Organon Teknika Corporation, Durham, N.C.) showed a positive growth.
The bacteria were isolated in 5% blood agar (Schaedler, bioMèrieux, France), being a facultative anaerobic organism whose growth was slightly enhanced by 5-10% CO2 when cultured in a beta atmosphere.
It was a gram-positive, non-acidophilic bacillus, irregular and catalase negative.
At the Apiyne test (API System, bioMèrieux, France) provoked the manifestation of beta xylose, lactose and lactose deficiency, beta-glucosides and glycosides.
No hydric acid was present, however, as well as acetaminophen and saccharose were negative.
C-test showed slight potentiation of hemolysis induced by Staph. aureus.
Other tests carried out in the caboxit group were pyrazinamidase (PI System, bioMèrieux, France) and agglutination with antibodies against Streptoco.
Antimicrobial resistance testing was performed by E-test (AB Biodisk, Solna, Sweden) in Mü Hinton agar with 5-10% CO2 for 48 hours.
Antibiogram results are shown in Table I.
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Other samples obtained from the patient as skin scraping or exudate or bronchial aspirate were negative for A. pyogenes.
