Bacterial infections caused by antibiotic-resistant isolates have become a major health problem in recent years, since they are very difficult to treat, leading to an increase in morbidity and mortality. Nitrofurantoin is a broad-spectrum bactericidal antibiotic that, through a complex mode of action which is not completely understood, affects both Gram-negative and Gram-positive bacteria. Nitrofurantoin has been used successfully for a long time for the prophylaxis and treatment of acute lower urinary tract infections in adults, children and pregnant women, but the increased emergence of antibiotic resistance has made nitrofurantoin a suitable candidate for the treatment of infections caused by multidrug-resistant pathogens. Here, we review the mechanism of action, antimicrobial spectrum, pharmacology and safety profile of nitrofurantoin. We also investigate the therapeutic use of nitrofurantoin, including recent data which highlight its role in the management of community urinary tract infection, especially in cases of multidrug-resistant isolates, in which oral active antimicrobials are limited resources nowadays.
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.
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.
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. Microscopy and culture are still widely used tools for mycobacterial disease diagnosis. Optimization of acid-fast bacilli (AFB) smear examination allows not only the detection of paucibacillary cases but also the selection of a greater number of specimens for direct molecular diagnosis. Acceptable sensitivity (S) of some molecular tests, which detect Mycobacterium spp. directly from specimens, is achieved only with smear-positive specimens (1). Traditionally, efforts to improve the sensitivity of microscopy have focused on chemical processing and sputum concentration.We describe a simple modification of the auramine (AU) staining procedure and our results of this staining method performed on concentrated-decontaminated respiratory specimens. This method involves the preparation of an UV-fixed thick blotch, which is described below. To prevent detachment of the sample in the staining process, the decontaminated specimen is placed on a dry blotch of BacT/Alert MP medium without antibiotic supplement, which acts as an adherent to the slide, and is then fixed overnight by UV light.To prepare the UV-fixed thick blotch, we proceeded as follows: the day before the specimen extension was made, one to two drops of BacT/Alert MP without supplements (bioMérieux, Spain) were placed and spread, forming an oval blotch in the center of the slide. After overnight drying, one to two drops of the decontaminated specimen sediment (N-acetyl cysteine-2% NaOH) (2) were deposited onto the dried Bact/Alert medium. Then, the slides are dried and fixed overnight by UV light (UV-C [100 to 280 nm]) within a type IIA biological safety cabinet (Heraeus HS12). Auramine staining was carried out using a ready-to-use kit (bioMérieux, Spain). When the staining is done correctly, a thick dark blotch is obtained, which makes identifying the specimen location on the slide very easy, as well as simplifying microscopic examination (Fig. 1).An expert microbiologist read the smears using epifluorescence microscopy (Nikon fluorescence microscope with a Nikon B-2A fluorescence filter set) under 20ϫ and 40ϫ objectives according to recommended procedures (3).To evaluate the effectiveness of this auramine staining adaptation, we calculated sensitivity differences between AFB smear and mycobacterial culture (BacT/Alert MP and Lowenstein-Jensen) in 722 respiratory specimens, 564 (78.2%) from
Introduction: Staphylococcus lugdunensis is a coagulase-negative staphylococci that is increasingly being reported as a human pathogen.Case presentation: Here, we describe a clinical case of urinary tract infection (UTI) due to S. lugdunensis in a 70-year-old woman with cystocele grade 3 who was successfully treated with cotrimoxazole. Although S. lugdunensis has rarely been reported to cause urinary tract infections and especially in immunosuppressed patients, we describe a case of UTI caused in an adult without the presence of an indwelling catheter or immunosuppression.Conclusion: S. lugdunensis can be a urinary tract pathogen in adults without the presence of indwelling catheters or other obvious medical problems. Urine cultures that show S. lugdunensis should not be attributed to skin contamination, especially when the clinical findings are compatible with cystitis or pyelonephritis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.