Microbiological Diagnosis of Osteoarticular Infections: Comparison between BacT/Alert Bottles and Schaedler Broth.

Microbiological diagnosis of osteoarticular infections (OAIs) is based on culture on several media. Experts recommend the use of liquid media, such as Schaedler broth, but many laboratories use blood culture media with automated detection instead for convenience. We aimed to evaluate the performance of culturing in BacT/Alert (bioMérieux) bottles for the microbiological diagnosis of OAI versus culturing in Schaedler broth. This prospective study was conducted on all osteoarticular specimens sent to the microbiology laboratories of the Versailles and Diaconesses Croix Saint-Simon hospitals between October 2016 and February 2017. Each sample was inoculated onto solid agar, into BacT/Alert bottles incubated for 14 days, and into a Schaedler broth incubated for 14 days with daily reading. The gold standard was defined as follow: OAI was diagnosed for a patient if at least two samples were positive for a nonskin microorganism and at least three for a cutaneous species. The times to detection were compared. A total of 1,616 specimens from 349 patients were collected. BacT/Alert bottles were significantly more sensitive than the Schaedler process for OAI diagnosis (114/135 OAI detected by BacT/Alert bottles; 91/135 OAI detected by Schaedler broth; +17.0% [95% confidence interval {CI}, 6.8%, 27.3%]; P = 0.0004). The time to detection was significantly shorter using BacT/Alert bottles (2.0 ± 2.2 days) than using Schaedler broth (4.6 ± 3.6 days, P < 0.0001). The culture of osteoarticular specimens in BacT/Alert bottles allows bacterial enrichment with an automated detection of positivity. Their use decreased detection time and increased sensitivity, making it a useful tool for the diagnosis of OAI that should be included among the recommended media. IMPORTANCE Microbiological diagnosis of OAI is based on culture on several media. French experts recommend the use of liquid media such as Schaedler broth, but many laboratories use blood culture media with automated detection in substitution because it is more convenient. We report here a prospective multicentric study evaluating the performance of culture in BacT/Alert (bioMérieux) bottles for microbiological diagnosis of OAI in comparison with culture in Schaedler broth. A total of 1,616 osteoarticular specimens from 349 patients were collected and inoculated onto agar, into BacT/Alert aerobic and anaerobic bottles, and into a Schaedler broth. BacT/Alert bottles were significantly more sensitive than the Schaedler process for OAI diagnosis (+17.0% [95% CI, 6.8%, 27.3%], P = 0.0004). The time to detection was significantly shorter for the BacT/Alert bottles (2.0 ± 2.2 days) than for Schaedler broth (4.6 ± 3.6 days, P < 0.0001). This study suggests that the use of BacT/Alert bottles should be recommended in microbiological diagnosis of OAI.

[Pathological analysis, an original way to study foodstuffs]. / L'anatomie pathologique, une méthode d'étude originale des denrées alimentaires.

AIM: To study the composition of foodstuffs (sausage, merguez, chipolata) on microscopic examination. MATERIAL AND METHODS: Six sausages, merguez, and chipolatas, sold in supermarkets were studied. The samples were weighed before and after dehydration to assess the water composition. Foodstuffs specimens were formalin-fixed, paraffin-embedded and analyzed on microscopic examination. Proportions of different tissues were assessed by morphometric analysis. RESULTS: Specimens contained a high proportion of water (40 to 55%). Striated muscular fibers represented from 0.7 to 15.3% for the sausages and the merguez, and from 61 to 76.5% for the chipolatas. Sausages and merguez contained from 43.3 to 49.2% of adipose tissue. All the specimens had fibrous tissue and most of them had small fragments of bone and cartilaginous tissue. Fragments of salivar glands were found in the sausages and fragments of lymphoid tissue were found in merguez. There were neither parasite nor brain tissue. Manufacturer wrote on the label the presence of "meat" with no information about the nature and the proportion of tissues in the foodstuffs specimens. Prices of the foodstuffs were globally correlated to the quantity of muscular fibers in the specimens. CONCLUSION: Pathological studies are not performed in France for the control of foodstuffs. Microscopic analysis could be interesting, as well as biochemical and bacteriological studies, in order to identify the nature and the proportion of tissues involved in the composition of the foodstuffs, to search tissues with potential risk of pathogenic agents transmission, and to search for some parasites.