The Simple One-Step (SOS) Stool Processing Method for Use with the Xpert MTB/RIF Assay for a Child-Friendly Diagnosis of Tuberculosis Closer to the Point of Care.

Young children cannot easily produce sputum for diagnosis of pulmonary tuberculosis (TB). Alternatively, Mycobacterium tuberculosis complex bacilli can be detected in stool by using the Xpert MTB/RIF (Ultra) assay (Xpert). Published stool processing methods contain somewhat complex procedures and require additional supplies. The aim of this study was to develop a simple one-step (SOS) stool processing method based on gravity sedimentation only, similar to Xpert testing of sputum samples, for the detection of M. tuberculosis in stool samples. We first assessed whether the SOS stool method could provide valid Xpert results without the need for bead-beating, dilution, and filtration steps. We concluded that this was the case, and we then validated the SOS stool method by testing spiked stool samples. By using the SOS stool method, 27 of the 29 spiked samples gave valid Xpert results, and M. tuberculosis was recovered from all 27 samples. The proof of principle of the SOS stool method was demonstrated in routine settings in Addis Ababa, Ethiopia. Nine of 123 children with presumptive TB had M. tuberculosis-positive results for nasogastric aspiration (NGA) samples, and 7 (77.8%) of those children also had M. tuberculosis-positive Xpert results for stool samples. Additionally, M. tuberculosis was detected in the stool samples but not the NGA samples from 2 children. The SOS stool processing method makes use of the standard Xpert assay kit, without the need for additional supplies or equipment. The method can potentially be rolled out to any Xpert site, bringing a bacteriologically confirmed diagnosis of TB in children closer to the point of care.

A five-year antimicrobial resistance pattern of Shigella isolated from stools in the Gondar University hospital, northwest Ethiopia.

Shigellosis is a global health problem. However, developing countries, where there is poor hygiene and unsafe water supplies, are especially affected. In the last two decades Shigella isolates have become increasingly resistant to many commonly used drugs. We investigated the antibiotic susceptibility pattern of Shigella isolated from stool specimens processed over five years in the bacteriology laboratory of the University of Gondar Teaching Hospital in northwest Ethiopia. Stool specimens were processed using standard bacteriological methods and data on bacterial culture, isolation and antimicrobial sensitivity were collected in the laboratory logbook. From a total of 2891 cultures stool specimens, 214 yielded Shigella. The overall sensitivity of Shigella to the commonly used antibiotics was: gentamicin (92.1%), ciprofloxacin (91.1%), chloramphenicol (47.2%), cotrimoxazole (26.6%), ampicillin (20.1%) and tetracycline (14%). About 46% of the isolates were resistant to at least three of the most commonly used drugs and 1.4% were resistant to all the commonly used drugs. The results demonstrated continued sensitivity of Shigella to gentamicin and ciprofloxacin and widespread resistance to tetracycline, ampicillin and cotrimoxazole. It is recommended that the use of gentamicin and ciprofloxacin be strictly regulated in the treatment of severe cases in regions where shigellosis is endemic and where the occasional epidemics result in high mortality.

A retrospective analysis of prevalence and antimicrobial susceptibility patterns of Staphylococcus aureus in Gondar teaching hospital, 2001-2005.

BACKGROUND: The current anti-staphylococcal therapy is increasingly compromised by the emergence and spread of resistant strains. The presence of multi-drug resistant bacteria is a great threat and because of the increasing members of resistant strains with time, updated information on prevalence and sensitivity of local major pathogens is of paramount importance. OBJECTIVES: To determine the prevalence of S. aureus infections among outpatients and inpatients and the drug resistance patterns of the isolates to the commonly used antimicrobials. MATERIALS AND METHODS: The study is a laboratory based retrospective analysis of different bacteriological specimens which were processed for culture and antimicrobial susceptibility testing in the bacteriology laboratory of the University of Gondar Teaching hospital from September 2001 to August 2005. RESULTS: Of the 616 isolates of S. aureus from different clinical specimens, the highest rate of isolation was from pus cultures (38.5%) followed by urine (32.5%). The isolates showed high level of drug resistance against tetracycline (68.3%), penicillin (54.9%), ampicillin (49.7%), trimethoprim-sulfamethoxazole (48.2%), and chloramphenicol (44.2%) but a moderate degree of resistance to erythromycin (21.6%) and gentamicin (19.6%). Resistance to ciprofloxacin was found only in 6.8% of the isolates. The isolates also showed increased resistance to the antibiotics tested with passage of time (from 2001 through 2005) and higher resistance was observed among ward isolates compared to the outpatients. CONCLUSION: Our results demonstrate the existence of multidrug resistant strains of S. aureus in Gondar indicating a strong need to ease selective antibiotic pressure to limit spread of drug resistance in the region. A continuous surveillance of antimicrobial susceptibility patterns and strong antibiotic policies are needed in order to minimize the emergence and spread of resistant pathogenic bacteria.