Impact of the Gen-Probe Amplified MTD® Test on tuberculosis diagnosis in children

OBJECTIVE

To evaluate the performance of the Gen-Probe Amplified MTD® Test (AMTD) for childhood tuberculosis (TB) diagnosis compared to conventional culture.

DESIGN

We retrospectively studied 121 childhood cases (73 males; median age 7 years, range 1-16). Pulmonary samples (104/152, 68%) included gastric aspirates (n = 53), induced sputum samples (n = 43), bronchial aspirates and bronchoalveolar lavage (n = 8). Extra-pulmonary samples (48/152, 32%) included lymph nodes (n = 34) and other sterile fluids (n = 14). Specimens were examined using acid-fast bacilli (AFB) microscopy, AMTD and bacterial culture using BACTEC™ MGIT™ 960 and Löwenstein-Jensen (LJ) media.

RESULTS

A clinical diagnosis of TB was made in 50/121 (41%) children (43/50 pulmonary disease). AFB microscopy was positive in 6%; Mycobacterium tuberculosis was recovered by culture from 16/50 (32%) and AMTD was positive in 29/50 (58%). AMTD sensitivity, specificity, positive predictive value and negative predictive value compared to culture were respectively 100%, 85%, 50% and 100%. For pulmonary vs. extra-pulmonary disease, the performance of AMTD compared to culture was respectively 100%, 77%, 46% and 100% vs. 100%, 97.5%, 75% and 100%.

CONCLUSIONS

Nucleic acid amplification tests are more sensitive and very specific methods for the rapid detection of M. tuberculosis. The AMTD technique increases TB detection in children compared to conventional culture.

Tuberculosis in Greece: bacteriologically confirmed cases and anti-tuberculosis drug resistance, 1995-2009

The Greek National Reference Laboratory for Mycobacteria is a major source of tuberculosis (TB)-related data for Greece, where the TB burden and epidemiology still need to be better defined. We present data regarding newly diagnosed TB cases and resistance to anti-TB drugs during the last 15 years in Greece. Although the total number of newly detected ?? cases has declined, cases among immigrants are increasing. Resistance to first-line anti-TB drugs is widely prevalent, although stable or declining. The implementation of an efficient and effective countrywide TB surveillance system in Greece is urgently needed.

Tuberculosis in Greece: bacteriologically confirmed cases and anti-tuberculosis drug resistance, 1995-2009

The Greek National Reference Laboratory for Mycobacteria is a major source of tuberculosis (TB)-related data for Greece, where the TB burden and epidemiology still need to be better defined. We present data regarding newly diagnosed TB cases and resistance to anti-TB drugs during the last 15 years in Greece. Although the total number of newly detected TB cases has declined, cases among immigrants are increasing. Resistance to first-line anti-TB drugs is widely prevalent, although stable or declining. The implementation of an efficient and effective countrywide TB surveillance system in Greece is urgently needed.

Nationwide surveillance of Streptococcus pneumoniae in Greece: patterns of resistance and serotype epidemiology

This nationwide study assessed the antimicrobial susceptibility and seroprevalence of Streptococcus pneumoniae in paediatric carriage isolates and in clinical isolates from adult pneumococcal disease in Greece during the years 2004-2006. Among 780 isolates recovered from the nasopharynx of children <6 years old attending day-care centres, non-susceptibility rates to penicillin, cefuroxime, ceftriaxone, erythromycin, tetracycline and trimethoprim/sulfamethoxazole were 34.7%, 25.1%, 1.0%, 33.5%, 26.4% and 44.2%, respectively. Among 89 adult clinical isolates, the respective rates were 48.3%, 46.1%, 5.6%, 48.3%, 32.6% and 40.4%. High-level resistance to penicillin, cefuroxime and ceftriaxone was recorded for 14.4%, 23.3% and 0.1% of paediatric carriage isolates, whereas for clinical adult isolates the respective rates were 25.8%, 38.2% and 2.2%. No resistance to levofloxacin and moxifloxacin was recorded, although 3.5% of paediatric carriage isolates and 23.2% of adult clinical isolates had minimum inhibitory concentrations of ciprofloxacin >2mg/L. Serotypes 19F, 14, 23F and 6B were the most prevalent among carriage and clinical isolates. The 7-valent pneumococcal conjugate vaccine was estimated to provide coverage against 71.7% of paediatric carriage isolates and 51.3% of adult clinical isolates. Resistance rates among clinical isolates from adult sources were higher than those recorded among paediatric carriage S. pneumoniae isolates and displayed an increasingly resistant profile compared with previous reports from our country, warranting continuous vigilance.

Antimicrobial resistance of Mycobacterium tuberculosis isolates from children in Greece, 1994-2004

OBJECTIVE

To document the prevalence of resistance to various agents of Mycobacterium tuberculosis strains derived from children over 1994-2004.

DESIGN

We prospectively studied the susceptibility patterns of 77 strains of M. tuberculosis isolated from the same number of children, which provided 112 positive samples.

RESULTS

Most children were boys (53.2%), native Greeks (87%) and aged under 2 years (41.5%). Sample origin was mainly gastric fluid (97 cases, 86.6%). Sixty-one isolates (79.2%) were susceptible to all anti-tuberculosis agents and 16 (20.8%) were resistant to > or =1 drug. Multidrug resistance (MDR), resistance to at least isoniazid (INH) and rifampicin (RMP), was seen in three cases (3.9%). On comparing resistance to INH, RMP and streptomycin (SM) and MDR in children and adults diagnosed with tuberculosis in our centre during the same time period, SM resistance was significantly more common in children (P < 0.001), while a trend for increased resistance to INH was also observed in children (P = 0.079).

CONCLUSION

Resistance of M. tuberculosis isolates to the first line anti-tuberculosis drugs appears to be comparable in children and adults in Greece, while SM resistance appears to be more common in children. Tracing the sources of these children is important for the effective surveillance and treatment of tuberculosis.

Comparison of the manual Mycobacteria Growth Indicator tube and the Etest with the method of proportion for susceptibility testing of Mycobacterium tuberculosis

BACKGROUND

Clinical microbiology laboratories should provide reliable results on susceptibility testing of Mycobacterium tuberculosis to different agents.

METHODS

The manual Mycobacteria Growth Indicator Tube (MGIT) and Etest were compared to the method of proportion (MOP) for susceptibility testing of 88 clinical isolates of M. tuberculosis against isoniazid (INH), rifampin (RIF), streptomycin (STR) and ethambutol (EMB). Isolates were recovered from different patients and were identified at species level by PCR and hybridization.

RESULTS

Resistance to INH was detected in 20.5, 29.5 and 12.5% of the isolates, followed by STR resistance (19.3, 26.1 and 1.1%), RIF (9.1, 4.5 and 5.7%) and EMB (2.3, 11.4 and 2.3%) by the MOP, MGIT and Etest, respectively. Sensitivity of the manual MGIT ranged from 37.5% for RIF resistance to 100% for EMB, while Etest sensitivity ranged from 5.9% for STR to 62.5% for RIF.

CONCLUSIONS

MOP remains the method of choice, with the manual MGIT showing superior sensitivity at detecting resistance to INH, STR and EMB compared to the Etest.

Resistance of Mycobacterium tuberculosis isolates in different populations in Greece during 1993-2002

OBJECTIVE

To document the prevalence of resistance of Mycobacterium tuberculosis to isoniazid (INH), rifampicin (RMP) and both combined (multidrug resistance [MDR]) in Greece from 1993 to 2002.

DESIGN

We studied a single sputum sample per patient from 4108 patients referred to the Greek National Referral Centre for Mycobacteria. Patients were divided into native Greeks, immigrants and repatriated Greeks originating from the former Soviet Union. Prior treatment status was not recorded.

RESULTS

A statistically significant increase in resistance to INH and RMP and MDR was noted comparing the years 1993-1997 to 1998-2002 (P < 0.0001). Resistance to INH and RMP and MDR rose from 5.6% to 7.71%, from 1.57% to 4.49% and from 1.23% to 3.98%, respectively, among native Greeks and from 23.63% to 32.91%, from 6.36% to 15.19% and from 6.36% to 13.92% among repatriated Greeks. Smaller changes were seen among immigrants (from 15.43% to 9.57% for INH, from 5.51% to 6.12% for RMP and from 5.71% to 5.32% for MDR).

CONCLUSION

We documented an increase in M. tuberculosis resistance to INH and RMP, and MDR. This was mainly limited to native and repatriated Greeks. Although this is likely the result of immigration and of mismanagement of index cases in Greece, molecular methods are needed to better describe the situation.

Antimicrobial resistance of Streptococcus pneumoniae isolates in Athens, Greece

In order to determine the current antibiotic susceptibility of Streptococcus pneumoniae strains in Greece, the present study was performed on 282 clinical isolates collected from patients at the Sotiria Chest Hospital of Athens, Greece, during the years 1997-2003. Susceptibility testing revealed that 52 (18.4%) isolates were not susceptible to penicillin, with 13.1% demonstrating intermediate and 5.3% high-level resistance. One of the penicillin-non-susceptible isolates was also resistant to cefotaxime. Comparison with results of a previous study conducted at the same hospital during the period 1992-1993 showed that penicillin resistance had increased by 4.5%. The results of this study indicate the antimicrobial susceptibility of Streptococcus pneumoniae continues to change in Greece and continuous surveillance remains important for guiding empirical antibiotic therapy.

In vitro activity of telithromycin (HMR 3647) against Greek Streptococcus pyogenes and Streptococcus pneumoniae clinical isolates with different macrolide susceptibilities

The susceptibilities to macrolides and telithromycin of 161 Streptococcus pyogenes and 145 Streptococcus pyogenes strains, consecutively isolated from five Greek hospitals, were determined by Etest. Moreover, mechanisms of resistance to macrolides were phenotypically and genetically determined by double disk induction test and PCR, respectively. Of the S. pneumoniae and S. pyogenes isolates, 42.8% and 30.8%, respectively, were found to be resistant to erythromycin. Of the erythromycin-resistant S. pneumoniae and S. pyogenes isolates, 57.5% and 59.5%, respectively, displayed the M phenotype and harbored the mefA/E gene. Telithromycin was found to be more active than both erythromycin and clarithromycin against both species, with considerably lower MIC50 and MIC90 values.

Brachyspira (Serpulina) pilosicoli spirochetemia in an immunocompromised patient

The case of an elderly immunocompromised man with non-Hodgkin's lymphoma who presented with fever, abdominal pain and bloody diarrhea is described. Brachyspira pilosicoli was isolated from culture. The patient was treated with penicillin G i.v. and became afebrile. B. pilosicoli is a recently recognized enteric pathogen of humans and animals. Intestinal spirochetosis should be included in the differential diagnosis of any immunocompromised or critically ill patient with dysentery.

Transfusion-mediated Yersinia enterocolitica septicemia in an adult patient with beta-thalassemia

We report a case of transfusion-mediated Yersinia enterocolitica septicemia in a 43-y-old woman with homozygous beta-thalassemia. Two h after transfusion of 3 units of red blood cells the patient suffered high-grade fever and shaking chills. Y. enterocolitica serotype O3 grew in blood cultures. Prolonged treatment with i.v. ceftriaxone plus ciprofloxacin led to a favorable outcome. Transfusion-associated Y. enterocolitica septicemia has not previously been reported in an adult beta-thalassemic patient from the Mediterranean area. Our report is particularly important, because of the high incidence of chronically transfused thalassemic patients in Mediterranean countries.

Effects of cefepime and meropenem on the gastrointestinal colonization of surgical patients by Candida albicans

BACKGROUND

The study evaluated the effects of cefepime and meropenem on the gastrointestinal (GI) colonization of surgical patients by Candida albicans.

PATIENTS AND METHODS

Twenty adult surgical patients who received intravenously either of these antibiotics as monotherapy for the treatment of an existing infection were studied prospectively. Ten patients received cefepime (2.0 g twice a day), and another ten meropenem (1.0 g every 8 h) for 7 days. Quantitative stool cultures for C. albicans were performed immediately before, at the end, and 1 week after the end of antibiotic treatment.

RESULTS

Both antibiotics increased the GI colonization of patients by Candida. Meropenem caused a higher increase (2.0 log(10) CFU/g of stool) as compared to cefepime (1.7 log(10) CFU/g of stool). However, these increases were statistically not significant.

CONCLUSION

Cefepime and meropenem when given to sensitive patients do not increase significantly the risk of Candida infection originating in the GI tract.

Effect of cefamandole, cefuroxime and cefoxitin on yeast fecal flora of surgical patients

Aim of the present study was to evaluate the effect of cefamandole, cefuroxime and cefoxitin on the level of gastrointestinal (GI) colonization by Candida albicans in humans. Twenty-eight adult patients received one of these three cephalosporins for 10 days, as treatment of infection, and were studied prospectively. Quantitative stool cultures for yeasts were performed immediately before, at the end, and 1 week after discontinuation of treatment. All three antibiotics caused an increase of the yeast concentration in the fecal flora. The increase caused by cefoxitin was the highest (2.5 log10 CFU/g of stool). Our results suggest that the cephalosporins tested cause minor increases of the colonization of the GI tract by C. albicans.

Antibiotic resistance of clinical isolates of Streptococcus pneumoniae in Greece

The antibiotic susceptibilities of 1,002 Streptococcus pneumoniae clinical isolates from patients with community-acquired pneumonia were determined over an 18-month period. Resistance rates were 14% for penicillin, 20% for erythromycin, 26% for tetracycline, and 1% for chloramphenicol. Resistance to non-beta-lactam antibiotics was associated with penicillin resistance at statistically levels.