There is a lack of data about Candida infections in Mexico despite their frequency and the severe infections that they can cause. Mainly information about yeast infections is from Mexico City and a few investigations have been conducted for other parts of the country [2, 22]. Our study address, in one year 105 isolates from different human sites and tested for antifungal effects. Here, the results showed a correlation between risk factors (diabetes mellitus, hypertension, renal failure, and obesity) and mycoses. The relation between these comorbidities predisposes patients as more vulnerable to fungal infection, mainly candidiasis and cryptococcosis. [2, 22] The mortality rate found in HGQ was 25.8% lower than the Brazilian rate ranging from 54–72.2% and similar to that found in studies in China (23.3%) [23].
We described the distribution of the most frequent species of the genus Candida: C. albicans, C. glabrata, C. tropicalis, C. parapsilosis, and C. krusei [12] and Cry. neoformans (1.9%). Our report highlight, the predominance of Non-albicans Candida species (57.2%), C. glabrata being the most frequent which may a cause of concern in the management of candidiasis. According to de la Torres-Saldaña et al. [24] and Reyes-Montes et al. [2] C. albicans is the most frequent etiological agent isolated from Mexican patients. However, González et al. [] found a prevalence of non-albicans Candida species in hospitals in Monterrey, Mexico similar to that described here. In tropical countries such as Brazil and India, common causes of nosocomial candidemia are C. parapsilosis and C. tropicalis, respectively [12, 14]. According to Manzano-Gayosso et al. [25], the etiology of Candida infections in Mexico has changed in the last 20 years, with non-albicans Candida species being more prevalent.
Regardless of Candida infection etiology, the antifungal most used in public hospitals in Mexico is FLC [2] which has been broadly used in empirical therapy against disseminated mycoses [26]. However, indiscriminate use of FLC (for example prophylaxis) can produce a great economic and ecological impact [2, 17]. As well as generating resistant yeast, its efficacy rate has decreased, and it offers variable protection against non-albicans Candida species [12]. Based on differences in susceptibility to FLC, Jenks et al. [27] recommended the implementation of newer triazoles with antifungal activity such as voriconazole [28]. Therefore, Candida and Cryptococcus antifungal tolerance and the appropriate treatment of patients with proven infection, started as early as possible and selected through strategies, must be taken into consideration [12, 29].
In general, resistance to azoles, singularly to FLC, has been reported in Candida and Cryptococcus [2, 17]. Moreover, from the data generated here, ITR, FLC, and MCN were the most resistant antifungals, which contrasts with the use of FLC in therapy. The findings for C. glabrata resistance to azoles shown in this study are similar to those previously published [1, 30]. In contrast with Corzo-Leon et al. [17] and González et al. [1] we found high resistance of C. tropicalis and C. albicans to azoles and AMB. Also, C. parapsilosis was susceptible to all antifungal agents tested. According to González et al. [1], Pfaller and Diekema [30] and Corzo-Leon et al. [17], and based on our results, the use of FLC should not be continued for prophylaxis or in patients with recurrent yeast infections.
The limitations our study are, first some epidemiological data (such as previous infection, transfers between hospitals or previous exposure to antifungals) was not always available. Second the isolates were collected and analyzed for one year, the duration of the study could be extended. Third we did not collected samples from the hospital environment or health care workers, information that will help to understand the source and spread of infections. Finally, we could not be allowed to implement the therapy with the susceptible antifungals to each patient.
In conclusion is important to improve the identification and antifungal test (identification by PCR or susceptibility to echinocandins) of no albicans Candida species in ICU patients in Mexico. To ensure a specific identification, diagnosis, and selection of appropriate therapeutic strategies which should be based on antifungal susceptibility patterns and control measures for risk factors. Nevertheless, the use of standardized technology in diagnostics and research remains a major global challenge, especially in countries such as Mexico. All the aforementioned will allow a better understanding of the epidemiology and susceptibility patterns of fungal infection in Mexico and in other countries with limited resources.