Traditional marketed meats as a reservoir of multidrug-resistant Escherichia coli

This study aimed to analyze Escherichia coli from marketed meat samples in Peru. Sixty-six E. coli isolates were recovered from 21 meat samples (14 chicken, 7 beef), and antimicrobial resistance levels and the presence of mechanisms of antibiotic resistance, as well as clonal relationships and phylogeny of colistin-resistant isolates, were established. High levels of antimicrobial resistance were detected, with 93.9% of isolates being multi-drug resistant (MDR) and 76.2% of samples possessing colistin-resistant E. coli; of these, 6 samples from 6 chicken samples presenting mcr-1-producer E. coli. Colistin-resistant isolates were classified into 22 clonal groups, while phylogroup A (15 isolates) was the most common. Extended-spectrum β-lactamase- and pAmpC-producing E. coli were found in 18 and 8 samples respectively, with blaCTX-M-55 (28 isolates; 16 samples) and blaCIT (8 isolates; 7 samples) being the most common of each type. Additionally, blaCTX-M-15, blaCTX-M-65, blaSHV-27, blaOXA-5/10-like, blaDHA, blaEBC and narrow-spectrum blaTEM were detected. In addition, 5 blaCTX-M remained unidentified, and no sought ESBL-encoding gene was detected in other 6 ESBL-producer isolates. The tetA, tetE and tetX genes were found in tigecycline-resistant isolates. This study highlights the presence of MDR E. coli in Peruvian food-chain. The high relevance of CTX-M-55, the dissemination through the food-chain of pAmpC, as well as the high frequency of unrelated colistin-resistant isolates is reported.

Antibiogramj: A tool for analysing images from disk diffusion tests

BACKGROUND AND OBJECTIVES

Disk diffusion testing, known as antibiogram, is widely applied in microbiology to determine the antimicrobial susceptibility of microorganisms. The measurement of the diameter of the zone of growth inhibition of microorganisms around the antimicrobial disks in the antibiogram is frequently performed manually by specialists using a ruler. This is a time-consuming and error-prone task that might be simplified using automated or semi-automated inhibition zone readers. However, most readers are usually expensive instruments with embedded software that require significant changes in laboratory design and workflow.

METHODS

Based on the workflow employed by specialists to determine the antimicrobial susceptibility of microorganisms, we have designed a software tool that, from images of disk diffusion tests, semi-automatises the process. Standard computer vision techniques are employed to achieve such an automatisation.

RESULTS

We present AntibiogramJ, a user-friendly and open-source software tool to semi-automatically determine, measure and categorise inhibition zones of images from disk diffusion tests. AntibiogramJ is implemented in Java and deals with images captured with any device that incorporates a camera, including digital cameras and mobile phones. The fully automatic procedure of AntibiogramJ for measuring inhibition zones achieves an overall agreement of 87% with an expert microbiologist; moreover, AntibiogramJ includes features to easily detect when the automatic reading is not correct and fix it manually to obtain the correct result.

CONCLUSIONS

AntibiogramJ is a user-friendly, platform-independent, open-source, and free tool that, up to the best of our knowledge, is the most complete software tool for antibiogram analysis without requiring any investment in new equipment or changes in the laboratory.

Multidrug-resistant tuberculosis presenting as a solitary splenic mass in an immunocompetent patient

Here, we report a case of multidrug-resistant tuberculosis (TB) presenting as a solitary splenic mass in a 60-year-old immunocompetent patient. Splenic TB is unusual and, when present, is usually associated with disseminated disease in immunocompromised patients. A high level of suspicion is required for diagnosis, and, as occurred in our case, it may be an unexpected finding following surgery. Diagnosis was made by polymerase chain reaction, which showed the presence of Mycobacterium tuberculosis DNA. Interestingly, rifampicin- and isoniazid-resistant genes were detected in our analysis. Splenic TB diagnosis and treatment are reviewed.

Mutation rates at Y chromosome specific microsatellites

A collaborative work was carried out by the Spanish and Portuguese ISFG Working Group (GEP-ISFG) to estimate Y-STR mutation rates. Seventeen Y chromosome STR loci (DYS19, DYS385, DYS389I and II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS460, DYS461, DYS635 [GATA C4], GATA H4, and GATA A10) were analyzed in a sample of 3,026 father/son pairs. Among 27,029 allele transfers, 54 mutations were observed, with an overall mutation rate across the 17 loci of 1.998 x 10(-3) (95% CI, 1.501 x 10(-3) to 2.606 x 10(-3)). With just one exception, all of the mutations were single-step, and they were observed only once per gametogenesis. Repeat gains were more frequent than losses, longer alleles were found to be more mutable, and the mutation rate seemed to increase with the father's age. Hum Mutat 26(6), 520-528, 2005. (c) 2005 Wiley-Liss, Inc.

Treatment of Class II furcation lesions using an autogenous periosteal barrier

Over the last two decades, guided tissue regeneration has achieved significant advances in periodontal healing that confirm the efficacy of periodontal regeneration. Several types of barriers have been utilized to apply this principle to periodontal wound healing. The objective of this article is to review the literature and principles of guided periodontal tissue regeneration (GPTR) in the treatment of Class II furcation defects and to describe a surgical technique that utilizes the neighboring periosteum of the furcation lesion as a barrier for the clinical application of GPTR.

Intraoral cancellous bone autografts in the treatment of infrabony pockets

One hundred infrabony pockets with one- and two-wall bony defects were treated for reattachment. Mucoperiosteal flaps were raised, the tooth surfaces were scaled and planed, and the defects curetted. Flaps were sutured tightly and the sites protected with a surgical dressing. Antibiotic coverage was used in each case. Pre- and postoperative measurements were taken by the same clinician from the cemento-enamel junction to the base of the pocket. In 56 defects cancellous bone from the same patient was placed in the defect, and in 44 defects the treatment consisted only of open curettage without bone grafts. The results showed a trend towards more favourable clinical results using bone grafts; especially in the two-wall bony defects.