[Gastrostomy tubes: indications and infectious complications in a tertiary hospital]. / Sondas de gastrostomía: indicaciones y complicaciones infecciosas en un hospital terciario.

OBJECTIVE: Gastrostomy tube is the best option for long-term enteral nutrition. Among its limitations, infections represent the most frequent minor complication. Our aim is the knowledge of the number and type of gastrostomy tubes and its main indication in our hospital. In addition, prevalence of infectious complications was studied paying attention to the main etiologic agents and their antibiotic susceptibility. METHODS: Observational retrospective study from January 2010 to July 2015 through the electronic clinical history and the clinical microbiology laboratory software. Identification and antibiotic susceptibility of clinically significant isolates from patients with suspicion of gastrostomy tube infection have been analysed. RESULTS: Percutaneous endoscopic gastrostomy was performed in 203 patients (70.5%) and surgical gastrostomy in 85 (29.5%). The main reason identified for starting enteral nutrition through gastrostomy tube was malignant neoplasy, above all, lip, oral cavity and pharynx cancer (11.8%) and that from digestive organs (8.7%). Global prevalence of gastrostomy tube infection was 16.6%. The most common bacterial pathogens isolated were Staphylococcus aureus (21.3%), Pseudomonas aeruginosa (13.1%), and Escherichia coli (9.8%). The percentage of multi resistant isolates was 3.1%. CONCLUSIONS: Gastrostomy tube indications and type, and also, prevalence and microorganisms isolated from culture in infectious complications are similar to those described previously in the literature. The study allows the adaptation of the antibiotic prophylaxis and empirical antibiotic treatment thanks to the knowledge of the etiologic agents and their antibiotic susceptibility.

UV-fixed-thick-blotch preparation improves sensitivity of auramine staining.

We describe here a very simple modification of the auramine staining procedure based on preparation of a UV-fixed thick blotch which allowed us to reach an overall sensitivity of 0.82 (592 acid-fast bacillus [AFB]-positive specimens/722 initial respiratory specimens with positive mycobacterial culture) and sensitivities of 0.93 (526 AFB-positive specimens/564 culture-positive specimens) for Mycobacterium tuberculosis complex and 0.42 (66 AFB-positive specimens/158 culture-positive specimens) for nontuberculous mycobacteria.

Comparative evaluation of Vitek 2 identification and susceptibility testing of urinary tract pathogens directly and isolated from chromogenic media.

We evaluated the use of urine specimens for direct identification and antibiotic testing of urinary tract pathogens using the Vitek system. A total of 343 urine specimens from patients with suspected UTI were selected by pyuria and screened by Gram staining to detect bacteriuria. Of those, 132 were analysed after Gram staining, showing a high number of micro-organisms of a single morphological type. Direct susceptibility testing and identification were performed by using the Vitek system. Results were compared using the standard inoculation method based on the incubation of solid media. After sub-culture, 107 specimens grew a significant count of a single species and were used for the comparative analysis. The direct method correctly identified 88 isolates (82.3 %). When compared according to antibiotic susceptibility testing, the error rate was 2.4 % overall with 0.2 % very major, 0.4 % major and 1.8 % minor errors. 84.7 % of the Gram-negative bacilli had a complete susceptibility report in ≤ 8 h. This method offers the advantage of prompt processing and earlier reporting of complete results for positive urine specimens.

Comparative evaluation of Vitek 2 identification and susceptibility testing of Gram-negative rods directly and isolated from BacT/ALERT-positive blood culture bottles.

The performance of Vitek 2 was evaluated for the identification and susceptibility testing of Gram-negative bacilli directly from positive blood cultures bottles. Direct inoculation of the positive blood cultures with the Vitek cards ID-GN and AST-NO58 was compared with the standard inoculation method based on the sub-culture of the positive blood culture to agar. A total of 142 blood cultures were included in the study; of those, 119 were from patients' clinical samples, while 23 were artificially prepared with strains showing different mechanisms of resistance. A total of 136 (95.8%) strains were correctly identified to the species level, only 2 (1.4%) were mis-identified and 4 (2.8%) were not identified. Susceptibility results were available for all isolates tested against 17 antibiotics, thus, resulting in a total of 2,414 isolate/anti-microbial combinations. The error rate was 2.8% (67/2,414) overall; 0.6% (14/2,414) very major errors, 0.1% (3/2,414) major errors and 2.1% (50/2,414) minor errors. The direct method detected 88.5% (22/25) of the strains producing extended-spectrum beta-lactamases (ESBLs). The susceptibility agreement among the added strains with ESBL, AMPc hyperproduction, resistance to ceftazidime, carbapenems and cefepime was very high. Direct identification and susceptibility testing gave rapid and reliable results, reducing by 24 h the turnaround time of the microbiology laboratory.