Introduction. The objective of the present study was to compare the suitability of the B BACTEC™ Lytic/10 Anaerobic/F versus B BACTEC™ Plus Aerobic/F vials at the time of both Enterobacteriaceae ...recovery rate and detection time. Material and methods. Prospective observational study from September 2018 to January 2019 in which 150 bacteremia. The samples were incubated in the automated BD BACTEC ™ FX system (Becton Dickison). Results. A total of 180 Enterobacteriaceae were isolated: 93 B BACTEC™ Plus Aerobic/F and 87 from B BACTEC™ Lytic/10 Anaerobic/F belonging to 106 patients The urinary focus was the most frequent origin. The average detection time in both cases was not more than 15 hours. Conclusion. The combination of both bottles seems to be the best diagnostic strategy, thus reducing the detection time as well as increasing the recovery of Enterobacteriaceae. The combination of both vials could be implemented especially in selected situation of special urgency such as the sepsis code or critical patients.
The EUCAST EDef 9.3.2 procedure recommends visual readings of azole and amphotericin B MICs against
spp. Visual determination of MICs may be challenging. In this work, we aim to obtain and compare ...visual and spectrophotometric MIC readings of azoles and amphotericin B against
isolates. A total of 847
isolates (
= 828 and cryptic species
= 19) were tested against amphotericin B, itraconazole, voriconazole, posaconazole, and isavuconazole using the EUCAST EDef 9.3.2 procedure. Isolates were classified as susceptible or resistant/non-wild type according to the 2020 updated breakpoints. The area of technical uncertainty for the azoles was defined in the updated breakpoints. Visual and spectrophotometric (fungal growth reduction of >95% compared to the control, read at 540 nm) MICs were compared. Essential (±1 2-fold dilution) and categorical agreements were calculated. Overall, high essential (97.1%) and categorical (99.6%) agreements were found. We obtained 100% categorical agreements for amphotericin B, itraconazole, and posaconazole, and consequently, no errors were found. Categorical agreements were 98.7 and 99.3% for voriconazole and isavuconazole, respectively. Most of the misclassifications for voriconazole and isavuconazole were found to be associated with MIC results falling either in the area of technical uncertainty or within one 2-fold dilution above the breakpoint. The resistance rate was slightly lower when the MICs were obtained by spectrophotometric readings. However, all relevant
mutants were correctly classified as resistant. Spectrophotometric determination of azole and amphotericin B MICs against
isolates may be a convenient alternative to visual endpoint readings.
The genus Aeromonas belongs to the Aeromonadaceae family. A patient with a pancreas–kidney transplant had multiple episodes of abdominal sepsis after surgery. Aeromonas hydrophila was isolated in the ...ascitic and biliary fluid drains. After discharge, the patient had several diarrhea episodes, and A. hydrophila was isolated in four stool samples. We decided to test whether the one strain that we initially isolated in ascitic fluid was the same that appeared in the successive stool samples. Five isolates of A. hydrophila were found in the patient. Identification was performed using the MALDI-TOF system and confirmed via multiplex PCR. The analysis of the REP-PCR fingerprint patterns showed one cluster and confirmed that all isolates were related. We also demonstrated the virulent character of this species associated with genes encoding different toxins (act, alt, ast, hlyA, and aerA). The virulence of this species is associated with the expression of genes that encode different toxins, structural proteins, and metal-associated proteins. This case report highlights the severity of this disease, especially in immunocompromised patients, and its adequate treatment.
Candida haemulonii
complex (
Candida haemulonii
I,
Candida duobushaemulonii
II, and
Candida haemulonii
var
. vulnera
III) has become relevant in recent times, not so much because of a high incidence ...in human clinical sample cultures but because of its remarkable antifungal resistance. The objective of this study was to evaluate several methods for the identification of this uncommon species of
Candida
. Ten isolates of
C. haemulonii
were identified by biochemical and proteomic methods, and their antifungal susceptibility testing was performed by both commercial and reference methods. MALDI-TOF MS (Vitek MS and Vitek MS PRIME) and Vitek2 correctly identified these genera but API method did not. There was a good correlation between the commercial methods and the reference methods for the AST. In conclusion Vitek MS, Vitek MS PRIME, and Vitek2 systems, but not API32C, are reliable for identification of
C. haemulonii
complex. Furthermore, MALDI-TOF MS systems could identify to the subspecies level. Commercial methods for antifungal susceptibility testing are valid for the study of this species and confirm amphotericin B and to azole resistance.
Abstract
Objectives
To provide a basis for clinical management decisions in Purpureocillium lilacinum infection.
Methods
Unpublished cases of invasive P. lilacinum infection from the FungiScope® ...registry and all cases reported in the literature were analysed.
Results
We identified 101 cases with invasive P. lilacinum infection. Main predisposing factors were haematological and oncological diseases in 31 cases (30.7%), steroid treatment in 27 cases (26.7%), solid organ transplant in 26 cases (25.7%), and diabetes mellitus in 19 cases (18.8%). The most prevalent infection sites were skin (n = 37/101, 36.6%) and lungs (n = 26/101, 25.7%). Dissemination occurred in 22 cases (21.8%). Pain and fever were the most frequent symptoms (n = 40/101, 39.6% and n = 34/101, 33.7%, respectively). Diagnosis was established by culture in 98 cases (97.0%). P. lilacinum caused breakthrough infection in 10 patients (9.9%). Clinical isolates were frequently resistant to amphotericin B, whereas posaconazole and voriconazole showed good in vitro activity. Susceptibility to echinocandins varied considerably. Systemic antifungal treatment was administered in 90 patients (89.1%). Frequently employed antifungals were voriconazole in 51 (56.7%) and itraconazole in 26 patients (28.9%). Amphotericin B treatment was significantly associated with high mortality rates (n = 13/33, 39.4%, P = <0.001). Overall mortality was 21.8% (n = 22/101) and death was attributed to P. lilacinum infection in 45.5% (n = 10/22).
Conclusions
P. lilacinum mainly presents as soft-tissue, pulmonary or disseminated infection in immunocompromised patients. Owing to intrinsic resistance, accurate species identification and susceptibility testing are vital. Outcome is better in patients treated with triazoles compared with amphotericin B formulations.
The role of Aeromonas species in gastrointestinal disease is controversial. The aim of this study was to know the epidemiological distribution of Aeromonas spp. isolated from stool in our health ...area, determine the existence of diarrhea as a significant symptom, identification of existing species in our environment and association as co-pathogen.
It was a retrospective descriptive study of isolates of Aeromonas spp. in feces (2016-2020). The protocol for these isolates included coproculture, identification by MALDI-TOF (Vitek-MS®, BioMerieux) and confirmation by multiplex PCR.
A total of 366 Aeromonas spp. isolates were analyzed being Aeromonas caviae the most prevalent species (289, 78.7%). A total of 58 (15.8%) co-infections were identified, being more frequent in pediatric age (49;84.5%) (p=0.01) and mostly associated with Campylobacter spp.
Aeromonas spp. prove to be a gastrointestinal pathogen more frequently associated with co-infections in pediatric age, evidencing its appearance especially with Campylobacter spp.
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•Traditional methods of microbiological identification are complex and time-consuming.•Raman spectroscopy solves these problems as it is a fast and cheap technique that does not ...require sample preparation.•Raman spectroscopy combined with machine learning algorithms has great potential for identifying and classifying pathogenic microorganisms.
One of the problems that most affect hospitals is infections by pathogenic microorganisms. Rapid identification and adequate, timely treatment can avoid fatal consequences and the development of antibiotic resistance, so it is crucial to use fast, reliable, and not too laborious techniques to obtain quick results. Raman spectroscopy has proven to be a powerful tool for molecular analysis, meeting these requirements better than traditional techniques. In this work, we have used Raman spectroscopy combined with machine learning algorithms to explore the automatic identification of eleven species of the genus Candida, the most common cause of fungal infections worldwide. The Raman spectra were obtained from more than 220 different measurements of dried drops from pure cultures of each Candida species using a Raman Confocal Microscope with a 532 nm laser excitation source. After developing a spectral preprocessing methodology, a study of the quality and variability of the measured spectra at the isolate and species level, and the spectral features contributing to inter-class variations, showed the potential to discriminate between those pathogenic yeasts. Several machine learning and deep learning algorithms were trained using hyperparameter optimization techniques to find the best possible classifier for this spectral data, in terms of accuracy and lowest possible overfitting. We found that a one-dimensional Convolutional Neural Network (1-D CNN) could achieve above 80 % overall accuracy for the eleven classes spectral dataset, with good generalization capabilities.
The incidence of Campylobacter coli has increased and with greater resistance to antibiotics than Campylobacter jejuni.
To determine the epidemiology distribution of Campylobacter spp. in our health ...area, and the sensitivity to commonly tested antibiotics.
Retrospective descriptive study of cases of campylobacteriosis (2016-2020) recovered from stool cultures as laboratory routine protocol. Sensitivity was tested following EUCAST recommendations.
Of 1319 campylobacteriosis (C. jejuni 87.7%, C. coli 12.3%) we found a decrease in C. jejuni cases in 2019, and an increase in C. coli. Statistically significant differences were seen in age and gender distribution. The resistance percentages have generally decreased, with higher percentages of resistance in C. coli than in C. jejuni, being significant for erythromycin.
There is not an increase of C. jejuni and its resistance but there is a not alarming increase of incidence of C. coli and its resistance in our health area.
causes pyogranulomatous pneumonia in domesticated animals and immunocompromised humans.
spp. are environmental bacteria that have rarely been associated with human infections.
and
spp. are closely ...related actinomycetes. Phenotypic discrimination between
and
on the basis of their Gram stain morphology and colony appearance is problematic. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is a fast, reliable, and cost-effective method for identification of a wide variety of microorganisms. We have evaluated the performance of Bruker Biotyper versus that of Vitek MS for identification of a collection of 154 isolates identified at the source as
that includes isolates belonging to the genus
PCR amplification of the
gene, encoding a cholesterol oxidase, and 16S rRNA sequencing were considered the reference methods for
identification. Biotyper identified 131 (85.1%) of the 154 isolates at the species level, and this figure increased to 152 (98.7%) when the species cutoff was reduced from a score of ≥2.000 to ≥1.750. Vitek MS correctly identified at the species level 130 (84.4%) isolates as long as bacteria were extracted with ethanol but only 35 (22.7%) isolates when samples were prepared by direct extraction from colonies. The two systems allowed differentiation between
and
spp., but identification of all
sp. isolates at the species level needed sequencing of the 16S rRNA gene.
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