Evaluation of the MB/BacT system for recovery of mycobacteria from clinical specimens in comparison to Lowenstein-Jensen medium.

OBJECTIVE: To evaluate the performance of the MB/BacT system (Organon Teknika) in comparison to Lowenstein-Jensen (LJ) solid medium for recovery of mycobacteria from clinical specimens. METHODS: Two thousand three hundred and ten specimens (1626 respiratory, 593 urine, 60 body fluids, five tissue and 26 others) were inoculated in MB/BacT (0.5 mL) and on two LJ slants (0.25 mL each). N-acetyl-l-cysteine-NaOH (final concentration 2%) was used for decontamination. RESULTS: Two hundred and fifty-one (10.8%) mycobacterial isolates [190 Mycobacterium tuberculosis complex (MTBC) and 61 non-tuberculous mycobacteria (NTM)] were detected. Of these 251 isolates, 234 (93.2%; 181 MTBC and 53 NTM) were detected in MB/BacT and 169 (67.3%; 154 MTBC and 15 NTM) on LJ. The mean (median) times to detection of MTBC by MB/BacT and LJ were 13.8 (13) and 22.1 (20) days, respectively, while overall contamination rates were 7.7% and 8.1%, respectively. CONCLUSIONS: Sensitivity and time to detection were significantly better with MB/BacT than with solid LJ medium.

[The incidence of Staphylococcus saprophyticus in urine and its identification]. / Ucestalost Staphylococcus saprophyticus u urinu i njegova identifikacija.

Having in mind the known fact that Staphylococcus saproplyticus is one of the most common causes of acute urinary infections, especially in females in the generative period, we have studied its incidence in 12,556 urine samples (6,374 of females and 6,182 of males) taken at the clinics and polyclinics of the Military Medical Academy. For identification of Staphylococcus saprophyticus we have used disk-diffusion test for sensitivity to novobiocin. In order to check realiability of this test we have studied morphological and biochemical characteristics in 30 novobiocin-resistant and 30 novobiocin-sensitive strains of coagulase-negative staphylococci. Of 12,556 examined urine samples we have isolated 217 strains of coagulase-negative staphylococci (10(4) and more bacteria/ml of urine in pure culture). Of this number 33 strains (15.2%) were resistent to novobiocin and we have regarded them as Staphylococcus saprophyticus. The greatest incidence of novobiocin-resistant strains we have found in the urine of female patients treated at polyclinics (19, e.i. 57.6%). Resistence to novobiocin, formation of light yellowish pigment and absence of beta-hemolysis have shown to be satisfactory criteria in diagnosis of Staphylococcus saprophyticus from urine.

[Penicillin resistance in strains of Streptococcus pneumoniae]. / Rezistencija sojeva Streptococcus pneumoniae na penicilin.

The values of minimal inhibitory concentration (MIC) of penicillin were determined using the agar-dilution method for 114 strains of Streptococcus pneumoniae isolated during 1994 in the patients treated in hospital and outpatient clinics. Diminished susceptibility to penicillin was determined in 50 (43.8%) strains. High level of penicillin resistance was observed in 12 (10.5%) strains. Streptococcus pneumoniae cannot any more be regarded as the agent with presumed susceptibility to penicillin, but every isolated strain must be tested.

[Methicillin-resistant staphylococci. Identification and distribution in the hospital environment]. / Meticilin-rezistentni stafilokok. Identifikacija i zastupljenost u bolnickoj sredini.

Occurrence of methicillin resistant staphylococcal strains in hospital environment is more frequently found. These strains are multiresistant so that diseases caused by them require a special therapeutical approach. They are significant causative agents of intrahospital infections which may have epidemic character. Using two methods for detection of methicillin resistant staphylococcus 335 strains were tested. Methicillin resistance was found in 36 (20.6%) of 175 strains of St. aureus and 49 (30.5%) strains of coagulase negative staphylococci. The largest number of methicillin resistant strains is isolated from materials of patients hospitalized at surgical and hematological clinics.

[Serotyping and pyocin typing of Pseudomonas aeruginosa in a study of intrahospital infections]. / Serotipizacija i piocin tipizacija Pseudomonas aeruginosa u ispitivanju intrahospitalnih infekcija.

Typing of Pseudomonas aeruginosa strains is the necessary precondition for the study and control of intrahospital infection caused by this microorganism. Since O-serotype is considered to be the basic epidemiological marker we have studied presence and distribution of some O-serotypes of 235 Pseudomonas aeruginosa strains isolated from 131 patients. The following O-serotypes have been most frequently found: O11 (21%), O6 (18%) and O12 (16%). The combination of sero and pyocin typing proved the presence of epidemic strains at departments of burns and orthopedics.

[Analysis of bacterial flora in burn patients]. / Analiza bakterijske flore opecenih bolesnika.

Bacterial flora of burn wound smears and hemocultures of 25 patients with burns have been followed up and analysed in the period of one year. Pseudomonas auruginosa have been most commonly isolated from burn wound smears, in 406 (5.6%) and Staphylococcus aureus, in 371 (47.14) samples. The most important hemoculture isolates has been Staphylococcus aureus found in 34 (57.6%) of samples. One multiresistant strain of Staphylococcus aureus represented 91% of all Staphylococcus aureus strains isolated from hemocultures and 84% from burn wound smears. Serologic and pyocin typing of Pseudomonas auruginosa proved the presence of several epidemic strains.

[Personal experience in the treatment of tuberculosis in patients in war areas]. / Nasa iskustva u lecenju tuberkuloze kod obolelih sa ratnih podrucja.

In the four-year period (1991-1995), 96 tuberculosis patients from the war areas of former Yugoslavia were treated in the Clinic for Lung Diseases of Military Medical Academy, that makes 31% of total number of sick and treated for tuberculosis-309 (100%). In group I (patients from war areas) there were 45 cases of cavernous pulmonary tuberculosis (47%), 28 bilateral (29%), 16 pleurisy (16.7%) and 6 cases of extensive pulmonary tuberculosis (5.1%). Among 213 patients (100%) from group II (patients from FR Yugoslavia), 81 patients had cavernous pulmonary tuberculosis (38%), 49 patients had bilateral (23%), 33 patients had pleurisy (15.5%) and 6 patients had extensive pulmonary tuberculosis (2.8%). In group I the diagnosis was bacteriologically and/or histopathologically proved in 94.8% cases: by finding of acid-resistant bacilli in sputum and other biological materials in 69 patients (72%), by positive Löwenstein's cultures in 73 patients (76%) and by histopathological result of tuberculosis inflammation in 34 patients (35.4%). In group II tuberculosis was bacteriologically and/or histopathologically proved in 134 patients (63%) by acid-resistant bacilli in sputum and other biological materials, in 141 patient (66%) by positive Löwenstein's culture and in 71 patient by positive histopathological results. Pulmonary tuberculosis in war areas is characterized by greater frequency of severe clinical forms (cavernous, bilateral and extensive) and by high direct bacillarity.

[Significance of determination of certain clinical and laboratory parameters in the evaluation of severity and outcome in sepsis]. / Znacaj odredjivanja pojedinih klinicko-laboratorijskih parametara u proceni tezine i ishoda sepse.

Sepsis and its complications are severe clinical syndrome that is caused by systemic inflammatory response of the host to infection. Despite the use of common and numerous new therapeutic protocols, mortality from this severe disease is still very high. In the study are presented 155 patients (111 males, 44 females) of average age 49.6 years with mean septic score 12.9 (2-40). Mortality in our patients was 20.6%, septic shock developed in 31.6%, ARF in 20.0%, DIC in 12.9%, and MODS in 25.8% of patients. Positive correlation existed between initial sepsis score and mortality. Older age and the presence of primary diseases (34.2% of patients) were associated with significantly higher septic score and were good prognostic factor for the poor outcome of sepsis. Between mean arterial pressure in the first 24 h after the admission and mortality existed negative correlation (p < 0.05). Positive hemocultures were found in 69.7%, and bacterial infection in 78.7% of patients. GP bacteremia was found in 55.6% of patients and GN in 45.4% of all positive hemocultures. Confirmed bacteremia and bacteremia caused by GPB were associated with the higher mortality rate compared to the patients with negative hemocultures and GN bacteremia (p < 0.05). Concentrations of fibrinogen and urea in the blood at the admission in the patients with sepsis were very good prognostic factors of the disease outcome, and leukopenia, leukocytosis and neutropenia were associated with the increased mortality. Negative correlation existed between fibrinogen concentration and mortality (p < 0.001), while positive correlation (p < 0.001) existed between urea concentration and mortality. In the absence of more efficacious therapeutic protocols, fast recognition of the sepsis, evaluation of its severity, knowledge of the risk factors for its poor outcome and aggressive use of antibiotic and existing supportive therapy can significantly decrease high mortality of this too severe clinical syndrome.