Reliability of a Screening Method Using Antibiotic Disks to Detect Carbapenemases in Glucose-Nonfermenting Gram-Negative Microorganisms From Clinical Samples of a Regional Hospital in Southeastern Spain

BACKGROUND

Infections by glucose-nonfermenting gram-negative bacilli (NFGNB) pose a major public health problem due to multiresistance to beta-lactam antibiotics, especially plasmid-borne carbapenemases. Their detection by microbiology laboratories is challenging, and there is a need for easy-to-use and reliable diagnostic techniques. Our objective was to evaluate an in-house screening method to presumptively detect carbapenemases in NFGNB in a simple and clinically useful manner.

METHODS

The study included 175 NFGNB isolates from urinary, respiratory, and rectal samples. In a triple assay, isolates were incubated at 37°C for 24 h on three solid-culture media: MacConkey II Agar, 5% Sheep Blood Columbia Agar and Mueller Hinton II Agar; meropenem (MEM) and cefepime (FEP) disks were employed for screening. Studies were then performed on the inhibition halo diameter, scanning effects, and the appearance of mutant colonies, which were compared with those observed using the colorimetric Neo-Rapid CARB Kit and immunochromatography (NG5-Test Carba and K-Set for OXA-23). Receiver operating characteristic curves were constructed for these data.

RESULTS

Carbapenemases were expressed by 79/175 (45.1%): 19 Pseudomonas aeruginosa and 60 Acinetobacter baumannii. Optimal inhibition halo diameter cutoffs to detect this resistance on 5% sheep blood agar were as follows: 6 mm (MEM) and 6.5 mm (FEP) for P. aeruginosa (in the absence of scanning effects and mutations) and 10.5 mm (MEM) and 16 mm (FEP) for A. baumannii (even in the presence of scanning effects).

CONCLUSION

The combined utilization of MEM and FEP antibiotic disks in 5% sheep blood agar, measuring their inhibition haloes, offers an effective method to predict the presence of carbapenemases as resistance mechanism in P. aeruginosa and A. baumannii.

Preliminary reading of antibiogram by microdilution for clinical isolates in urine culture

PURPOSE

We evaluated a modification of automated antibiograms in urine cultures designed to facilitate the early interpretation of minimum inhibitory concentrations (MICs) and accelerate the targeted treatment of urinary tract infections (UTIs), METHODS: A prospective study was conducted of 309 isolates (219 Enterobacteriaceae, 75 Enterococcus spp., and 15 non-fermenting Gram-negative bacilli (NFGNB), and a retrospective study of 9 carbapenemase-producing clinical isolates from urine cultures. Colonies grown on conventional isolation plates were inoculated in MicroScan Walkaway system panels and incubated for 7 h, using a MicroScan AutoScan-4 plate reader for preliminary MIC determination by turbidimetry. Resulting antibiograms were compared with definitive antibiograms obtained after incubation for 17 h.

RESULTS

Preliminary and definitive readings were concordant for 86.7% of Gram-positive cocci isolates (65/75), 61.6% of Enterobacteriaceae (135/219), and 53.3% of NFGNB. The agreement rate was greater than 90% for most antimicrobials against Gram-positive cocci (94.7% or more) and Enterobacteriaceae, (97.2% or more for 10 of 17 antibiotics) except with nitrofurantoin (89%). The agreement rate was 86.7% or more for most antibiotics against NFGNB apart from piperacillin/tazobactam, aztreonam, amikacin, and ciprofloxacin. Gram-negative bacilli showed the highest differences in MIC values between preliminary and definitive readings.

CONCLUSIONS

A preliminary antibiogram reading may be useful in urine cultures to reduce the delay before targeted antibiotherapy, especially against Enterobacteriaceae and Gram-positive cocci, but not in cases of carbapenemase-producing NFGNB. Further local studies are warranted to evaluate the usefulness of this approach in relation to resistance rates.

Antibiotic resistances of Pseudomonas aeruginosa and Acinetobacter baumannii in urine cultures: experience in a hospital of Southeast Spain

The objectives of this study were to perform a systematic review of publications between 2010 and 2021 on the antibiotic resistance of Pseudomonas aeruginosa and Acinetobacter baumannii from urinary tract infections and to analyze changes over time in hospital urine cultures from 2016 through 2021. The literature was searched, and a retrospective cross-sectional descriptive study was performed in the hospital. Out of 21 838 positive urine cultures, 3.86% were due to P. aeruginosa and 0.44% were due to A. baumannii. For P. aeruginosa, lower resistance rates were observed to virtually all tested antibiotics than were obtained in the systematic review, and the present series of hospital samples showed an in vitro resistance rate <10% to ceftazidime, cefepime, meropenem, piperacillin-tazobactam, amikacin, tobramycin, and colistin. For A. baumannii, the resistance rates to almost all antibiotics were higher in the present series than in the systematic review, being lowest to colistin (10%). Both microorganisms show reduced in vitro susceptibility to some antibiotics during the years of the COVID-19 pandemic in comparison to previous years. In our setting, both piperacillin-tazobactam and meropenem can be recommended for the empirical treatment of UTIs by P. aeruginosa, whereas only colistin can be recommended for UTIs by A. baumannii.

Concerning the presumptive identification of Candida kefyr on Uriselect™4 agar

OBJECTIVE

Non-albicans Candida species, such as Candida kefyr, are emerging pathogens. Chromogenic media are highly useful for the diagnosis of urinary tract infections (UTIs). The aim was to describe the behavior of this specie on a non-specific chromogenic medium.

METHODS

A retrospective study of cases of candiduria detected in the Microbiology laboratory of the Virgen de las Nieves Hospital in Granada (Spain) between 2016 and 2021 (N=2,130). Urine samples were quantitatively seeded on non-selective UriSelect™4 chromogenic agar.

RESULTS

Between 2016 and 2021, C. kefyr was the seventh most frequent Candida species responsible for candiduria in our setting (n=15). The macroscopic appearance of C. kefyr colonies, punctiform and bluish, allowed the direct identification of these microorganisms.

CONCLUSIONS

This study provides the first description of the specific behavior of C. kefyr on UriSelect™4 agar, which differentiates it from other Candida species based on its enzymatic characteristics.

In vitro activity of delafloxacin against anaerobic bacteria compared with other antimicrobials

The aim of this study was to describe the in vitro activity of delafloxacin against 230 anaerobic isolates and compare it with the activity of other antimicrobials used against infections caused by anaerobic microorganisms. Minimal inhibitory concentrations (MICs) were lower for delafloxacin than for all other antibiotics tested with the exception of piperacillin-tazobactam and meropenem against Gram-positive anaerobic cocci. Only two (0.8 %) isolates of Bacteroides spp. showed a MIC ≥4 μg/mL. With some exceptions, the present results show lower MICs for delafloxacin in comparison to the other antibiotics used against anaerobes.

Bacteremia due to Clostridium innocuum: Analysis of four cases and literature review

Clostridium innocuum is a Gram-positive anaerobic spore-forming bacillus that has been identified as part of the normal intestinal microbiota. This bacterium has been rarely associated with human infections, and only few severe infections have been reported until now. In this work, we report on four patients with bacteremia due to C. innocuum, which were well identified by MALDI-TOF MS. Moreover, a review of the previous published cases of bacteremia due to this anaerobic bacterium has been performed.

[Isolation of Haemophilus no ducreyi in samples from the genital tract of men: Its clinical relationship]

INTRODUCTION

With the advancement of microbiological methods, the isolation of less typical pathogens in cases of urethral and rectal infection is more frequent, apart from the classic etiological agents. One of them is formed by species of Haemophilus no ducreyi (HND). The objective of this work is to describe frequency, susceptibility to antibiotics, and clinical features of HDN urethritis and proctitis in adult males.

PATIENTS AND METHODS

This is an observational retrospective descriptive study of the results obtained by the Microbiology laboratory of the Virgen de las Nieves University Hospital on the isolates of HND in genital and rectal samples from males between 2016 and 2019.

RESULTS

HND was isolated in 135 (7%) of the genital infection episodes diagnosed in men. H. parainfluenzae was the most commonly isolated (34/45; 75.6%). The most frequent symptoms in men with proctitis were rectal tenesmus (31.6%) and lymphadenopathy (10.5%); in those with urethritis, dysuria (71.6%), urethral suppuration (46.7%) and gland lesions (27%), so differentiating it from infections caused by other genitopathogens is difficult. 43% of patients were HIV positive. Antibiotic resistance rates for H. parainfluenzae were high to quinolons, ampicillin, tetracycline and macrolides.

CONCLUSION

HND species should be considered as possible etiologic agents in episodes of urethral and rectal infection in men, especially in cases with negative screening tests for agents that cause sexually transmitted infections (STIs). Its microbiological identification is essential for the establishment of an effective targeted treatment.

Clinical significance of isolation of Haemophilus no ducreyi in genital samples. Systematic review

INTRODUCTION AND OBJECTIVES

Currently, the microbiological diagnosis of genital infections is carried out with molecular methods, which allow the detection of less frequent etiological agents but with potential pathogenic importance, such as Haemophilus spp. The objective of this review is to analyse and highlight the clinical importance of the isolation of Haemophilus spp. in genital and rectal infections, excluding Haemophilus ducreyi.

MATERIAL AND METHODS

A systematic review was carried out based on an exhaustive search of the publications included in the MEDLINE database up to August 5, 2021, on the presence of Haemophilus spp. in genital and rectal infections, excluding H. ducreyi.

RESULTS

After reviewing what was described in the literature, Haemophilus spp. (excluding H. ducreyi: HSNOD) was detected in 2397 episodes of genital infection, the most frequently isolated species being H. influenzae and H. parainfluenzae. Most of the episodes (87,6%) are constituted by single isolation. There is a slight predominance in women (48,3%) where it can cause vaginitis, salpingitis, endometritis or complications during pregnancy. In men, the clinical picture usually corresponds to urethritis. Most of the samples correspond to vaginal and urethral exudates, with a minority representation at the rectal level (2.3%).

CONCLUSION

HSNOD plays a relevant pathogenic role in episodes of genital infection, so microbiological diagnostic protocols must include methods that allow their detection, as well as include them in the etiological spectrum of this type of clinical picture.

Comparative evaluation of MALDI-TOF MS and 16S rRNA gene sequencing for the identification of clinically relevant anaerobic bacteria: critical evaluation of discrepant results

OBJECTIVES

The main study objective was to evaluate the correlation between matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequencing results for the identification of anaerobes.

METHODS

A retrospective study was conducted of all anaerobic bacteria isolated from clinically significant specimens. MALDI-TOF (Bruker Byotyper) and 16S rRNA gene sequencing were performed in all strains. Identifications were considered correct when the concordance with gene sequencing was ≥99%.

RESULTS

The study included 364 isolates of anaerobic bacteria: 201 (55.2%) Gram-negative and 163 (44.8%) Gram-positive, mostly belonging to the genus Bacteroides. Isolates were largely obtained from blood cultures (128/35.4%) and intra-abdominal samples (116/32.1%). Overall, 87.3% of isolates were identified at species level using the version 9 database (89.5% of Gram-negative and 84.6% of Gram-positive anaerobic bacteria). All isolates belonging to the species B. fragilis sensu stricto were correctly identified by MALDI-TOF MS, but five cases of Phocaeicola (Bacteroides) dorei were misidentified as Phocaeicola (Bacteroides) vulgatus; all Prevotella isolates were correctly identified at the genus level, and most were correctly identified at the species level. Among Gram-positive anaerobes, 12 Anaerococcus species were not identified by MALDI-TOF MS, while six cases identified as Peptoniphilus indolicus were found to belong to other genera/species.

CONCLUSIONS

MALDI-TOF is a reliable technique for identifying most anaerobic bacteria, although the database needs frequent updating to identify rare, infrequent, and newly discovered species.

Antibiotic Resistance Changes in Gram-Positive Bacteria from Urine Cultures: Development Analysis in a Health Area of South-East Spain

This study analyzed the epidemiology and antibiotic susceptibility profile of significant bacteriuria and assessed the impact of adopting EUCAST criteria on antibiotic resistances. A systematic review was performed on publications in English or Spanish between 1 January 2010 and 30 June 2021 on the susceptibility of Gram-positive bacteria isolated in urinary samples in Europe. A retrospective descriptive study was also conducted on the results of 21,838 urine cultures with presumptive urinary tract infection (UTI) obtained during the past five years by the Department of Microbiology of the Virgen de las Nieves University Hospital (Granada, Spain). The activity of various antibiotics was determined, differentiated among various populations, and interpretations compared according to the application of EUCAST or CLSI criteria. Among 21,838 cases of significant bacteriuria, 27.69% were by Gram-positive bacteria, which were Enterococcus faecalis in 19.04% and Enterococcus faecium in 3.92%. The susceptibility profile remained stable for most antibiotics except for levofloxacin for E. faecalis and Staphylococcus aureus and nitrofurantoin for E. faecium. The resistance of Enterococcus spp. and Staphylococcus spp. to glycopeptides was exceptionally low in our setting. No significant difference in the prevalence of methicillin-resistant Staphylococcus aureus was observed between hospital (26.67%) and community (28.85%) samples. Resistances in our local setting remain stable and appear to be lower than reported in other studies. The adoption of EUCAST vs. CLSI criteria did not produce a general change in resistance rates. Findings suggest the need to revise certain empirical criteria, such as aminoglycoside synergy for Enterococcus and for community-origin S. aureus.

Evolution of Antibiotic Resistance in Escherichia coli and Klebsiella pneumoniae from Urine Cultures

OBJECTIVE

Determine the evolution of antibiotic resistance of symptomatic bacteriuria caused by Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) in Granada.

MATERIAL AND METHOD

A descriptive retrospective study was carried out, including antibiograms of urine cultures in which microorganisms identified as E. coli and K. pneumoniae, were isolated in the Microbiology laboratory of the Hospital Universitario Virgen de las Nieves (Granada, Spain) between January 2016 and June 2021.

RESULTS

E. coli was the most frequent isolate (10,048) and its resistance to ampicillin (59.45%) and ticarcillin (59.59%), and the increase to cefepime (15.07%) and amoxicillin-clavulanic acid (17.67%) is noteworthy. K. pneumoniae (2222) is notable for resistance to Fosfomycin (27.91%) and an increase to ciprofloxacin (37.79%) and amoxicillin-clavulanic acid (36.63%). Resistance is generally higher in hospitalized patients, males, and adults.

CONCLUSIONS

Antibiotic resistance to the studied Enterobacteriaceae is on the rise, requiring empirical treatment targeted to the population area.

Differences between bloodstream infections involving gram-positive and gram-negative anaerobes

BACKGROUND

The objectives of this study were to describe differences between bloodstream infections involving Gram-positive (GP) and Gram-negative (GN) anaerobic bacteria.

METHODS

Patients with clinically significant anaerobic bacteremia detected between October 2016 and July 2022 in a tertiary hospital in Granada (Spain) were retrospectively included. Species identification was performed by MALDI-TOF MS and/or molecular methods. The association between variables was analyzed using contingency tables, applying the chi-square test when expected frequencies were adequate and the Fisher exact test when not. Variables were gathered at the time of the first positive blood culture.

RESULTS

Out of 237 cases of anaerobic bloodstream infections detected, 127 (53.6%) were GN. Crude mortality was 20.3%, corresponding to 48 patients who died of causes directly attributable to bacteremia. The presence of malignant disease (p = 0.011), abdominal and/or pelvic surgery (p = 0.001), and transplantation (p = 0.008) were significantly associated with bacteremia due to GN bacteria, while the presence of diabetes mellitus was significantly associated with bacteremia due to GP bacteria (p = 0.022). The presence of both septic shock and mortality was more frequently associated with bacteremia due to GN versus GP bacteria.

CONCLUSIONS

The association of certain variables with the presence of bloodstream infections due to GP or GN anaerobic bacteria may assist in selecting the optimal empirical therapeutic approach and improving the outcome of patients with these types of infection.

Antibiotic Resistances of Enterobacteriaceae with Chromosomal Ampc in Urine Cultures: Review and Experience of a Spanish Hospital

The Enterobacteriaceae Citrobacter freundii, Enterobacter cloacae, Klebsiella aerogenes, Morganella morganii, Providencia stuartii, and Serratia marcescens (CESPM group) produce numerous urinary tract infections (UTIs) which are difficult to treat due to their high multiresistance rate. The objectives of this study were to carry out a systematic review of antibiotic resistances by UTIs and to determine changes over time in urine cultures from a reference hospital in southern Spain. The literature was searched for European data on the resistance rates of each microorganism, and a retrospective cross-sectional descriptive study was performed in samples with suspicion of UTI from patients in Virgen de las Nieves University Hospital (Granada, Spain) between 2016 and the first half of 2021. Among 21,838 positive urine cultures, 1.85% were caused by E. cloacae, 0.77% by M. Morganii, 0.65% by K. aerogenes, 0.46% by C. freundii, 0.29% by P stuartii, and 0.25% by S. marcescens. The lowest resistance rates by microorganism were: E. cloacae to amikacin (3.47%) and imipenem (5.28%); M. morganii to piperacillin-tazobactam (1.79%), cefepime (4.76%), and tobramycin (7.74%); K. aerogenes to tobramycin (3.55%), gentamicin (4.25%), trimethoprim-sulfamethoxazole (4.96%), imipenem (5.75%), and cefepime (6.43%); C. freundii to imipenem (no resistance), nitrofurantoin (1.96%), fosfomycin (2.80%), and ertapenem (6.12%); P. stuartii to cefepime (3.28%) and ceftazidime (3.28%); and S. marcescens to gentamicin (1.8%), ciprofloxacin (3.64%), cefepime (3.70%), piperacillin-tazobactam (3.70%), and trimethoprim-sulfamethoxazole (5.45%). In our setting, CESMP Enterobacteriaceae showed the lowest resistance to piperacillin-tazobactam, cefepime, imipenem, gentamicin, and colistin, which can therefore be recommended for the empirical treatment of UTIs. The COVID-19 pandemic may have had a clinical impact in relation to the increased resistance of E. cloacae and M. morgani to some antibiotics.

[Microbial etiology of bacterial chronic prostatitis: systematic review]

OBJECTIVE

The importance of Gram-positive microorganisms and atypical bacteria in chronic bacterial prostatitis (CBP) has recently been described. For this reason, this study analyzes the etiology of CBP, as well as the evolution of antibiotic resistance through a systematic review.

METHODS

A systematic review of studies obtained through the MEDLINE (PubMed) database, related to the etiology and antibiotic resistance profile of CBP, published up July 1, 2021.

RESULTS

The most frequent isolated microorganisms that we have found in publications are Enterococcus faecalis (46.90%), Staphylococcus spp. (22.30%), Escherichia coli (15.09%) and atypical bacteria (6.04%).

CONCLUSIONS

CBP is undergoing and unprecedented change of paradigm. Gram-positive bacteria and atypical bacteria are the main pathogens involved in the aetiology of this entity. This forces us to rethink the therapeutic strategy used, since it is necessary to use antibiotics that assume the etiological change and the profile of antibiotic resistance described.

Presence and Relevance of Emerging Microorganisms in Clinical Genitourinary Samples

Microorganisms responsible for genitourinary infections increasingly include species other than conventional etiological agents that are of clinical and pathogenic relevance and therapeutic interest. This cross-sectional descriptive study selected samples from clinical genitourinary episodes between January 2016 and December 2019 in which emerging microbiological agents were detected. The patients’ epidemiological characteristics, clinical presentation, antibiotic treatment, and outcome were studied to identify their pathogenic role. The emerging microorganisms most frequently detected in urinary tract infections were Streptococcus bovis (58.5%) and Gardnerella spp. (23.6%) in females and S. bovis (32.3%), Aerococcus urinae (18.6%), and Corynebacterium spp. (16.9%) in males, while the most frequently detected in genital infections were S. viridans (36.4%) in females and C. glucuronolyticum (32.2%) and Gardnerella spp. (35.6%) in males. All cases in female children were produced by S. bovis. Symptomatic episodes were more frequent with Aerococcus spp. and S. bovis and the presence of leukocytosis more frequent with Aerococcus spp. Quinolones and doxycycline were most often prescribed antibiotics for genital infections and quinolones and amoxicillin-clavulanic acid for urinary infections. Urinary infection by Aerococcus spp. was more frequent in males of advanced age, Corynebacterium spp. was more frequent in permanent vesical catheter carriers, and episodes of asymptomatic bacteriuria by Gardnerella spp. were more frequent in patients with kidney transplant and chronic consumers of corticosteroid therapy. Lactobacillus spp. should be considered in urinary infections of patients of advanced age and with a previous antibiotic load. Genital infection by Gardnerella spp. was significantly associated with a history of risky sexual relations.

[Shigellosis attended in the emergency department of a regional hospital in southeastern Spain: from their presence to multiresistance]

OBJECTIVE

In the bacterial etiology of severe acute infectious diarrhea, except that caused by Clostridioides difficile, most of them have an invasive character and antibiotic treatment will be necessary in specific situations. Shigella is a classic pathogen, in which it is crucial to know the sensitivity to different classic and alternative antimicrobials. The objective of this work was to analyze the presence of shigellosis and the rate of antibiotic resistance.

METHODS

A descriptive-retrospective study of the reports of shigellosis of stool cultures issued between January 2016 and April 2022 was conducted.

RESULTS

A total of 34 episodes (16 -47.1%- by Shigella sonnei) were observed, as of 2018. There were only 2 pediatric cases. The overall resistance rate to azithromycin, trimethoprim-sulfamethoxazole and ciprofloxacin was 52.9%, 64.7% and 44.1%, respectively. 26.5% were resistant to the 3 groups of antibiotics. There was a higher rate of resistance for S. sonnei. The emergence of resistance to cephalosporins in recent years stands out. Episodes of multidrug-resistant shigellosis were detected between 2020 (1 by S. flexneri) and 2022 (4 by S. sonnei).

CONCLUSIONS

The episodes of shigellosis are emerging in our environment with a higher rate of multi-resistance. In this context, current empirical treatments for acute enteroinvasive enteritis are at risk of failure, if necessary.

[Antibiotic resistance changes in episodes of symptomatic bacteriospermia: development in a health area of southeast Spain]

OBJECTIVE

Chronic bacterial prostatitis (CBP) is an entity of difficult clinical diagnosis and treatment, being the microbiological study of semen the main diagnostic test. This study aimed to determine the etiology and antibiotic resistance in patients with symptomatic bacteriospermia (SBP) in our environment.

METHODS

A cross-sectional and retrospective descriptive study has been carried out from a Regional Hospital of the Spanish Southeast. The participants were patients assisted in the consultations of the Hospital with clinic compatible with CBP, between 2016 and 2021. The interventions were collection and analysis of the results derived from the microbiological study of the semen sample. The main determinations were the etiology and rate of antibiotic resistance of BPS episodes are analyzed.

RESULTS

The main isolated microorganism is Enterococcus faecalis (34.89%), followed by Ureaplasma spp. (13.74%) and Escherichia coli (10.98%). The rate of antibiotic resistance of E. faecalis to quinolones (11%) is lower than previous studies, while for E. coli it has been higher (35%). The low rate of resistance shown by E. faecalis and E. coli to fosfomycin and nitrofurantoin stands out.

CONCLUSIONS

In the SBP, gram-positive and atypical bacteria are established as the main causative agents of this entity. This forces us to rethink the therapeutic strategy used, which will avoid the increase in antibiotic resistance, recurrences, and chronicity of this pathology.

New anaerobic bacteria causing infection: Bacteremia due to Murdochiellaasaccharolytica

Murdochiella asaccharolytica is a Gram-positive anaerobic coccus firstly isolated from wound specimens, since then, it was very rarely isolated from human infections. We report the first case of bloodstream infection due to this bacterium in a 90 years-old-man. The patient had a history of B-cell lymphoma and presented with pain and induration of the base of penis along with fever. A blood culture was obtained yielding M. asaccharolytica in pure culture. Only resistance to clindamycin was demonstrated. Treatment with metronidazole was started and the clinical evolution improved with antimicrobial treatment, being discharged after 6 days.

Brain abscesses caused by anaerobic bacteria

OBJECTIVES

The objective of this study was to review the characteristics, causative bacteria, treatment and outcomes of brain abscesses due to anaerobes in our health setting.

METHODS

A retrospective analysis of all brain abscesses caused by anaerobic bacteria over the period 2005-2021 was performed.

RESULTS

Out of 300 brain abscesses identified during the study period, 31 were produced by anaerobic pathogens, either alone (monomicrobial infection) or together with aerobic and/or anaerobic bacteria (polymicrobial infection). The mean age of the 31 patients was 53 years, and 61.2% were male; 51.6% of infections were polymicrobial, with only four (12.9%) caused by anaerobic bacteria alone. Forty-three anaerobic bacteria were isolated: Cutibacterium acnes in thirteen (41.9%), Parvimonas micra in eight (25.8%), and Prevotella spp. in seven (22.5%). The most frequent etiologies were local neurosurgery (13/41.9%) and contiguous otogenic, oral, or sinus foci of infection (8/28.8%). Cancer was present in eight patients (28.8%), headaches in seventeen (54.8%), and fever in nine (28.8%). All patients received both surgery and antimicrobial therapy. The abscess was in the frontal region in 12 patients (38.7%) and in the parietal region in 11 (35.4%). A good outcome was obtained in all patients.

CONCLUSIONS

Anaerobes were isolated in 10.3% of patients with brain abscesses in our health setting, similar to other reports. C. acnes was the most frequently detected anaerobe, especially in neurosurgical patients.

Bacteremia due to Parabacteroides distasonis: Experience with 4 cases

OBJECTIVE

To report a series of four uncommon cases of bacteremia due to Parabacteroides distasonis.

METHODS

We have analyzed the epidemiological characteristics, clinical features, diagnostic methods, treatment and outcome of these patients.

RESULTS

Two sets of blood cultures of each patient yielded a pure culture of an anaerobic microorganism identified as P. distasonis by MALDI-TOF MS, and confirmed by 16S rRNA gene sequencing. All patients were male and they had risk factors for anaerobic bacteremia. All isolates were susceptible to metronidazole and the outcome was successful in three patients.

CONCLUSIONS

Bloodstream infections due to P. distasonis are still rare. MALDI-TOF MS appear to be an excellent tool for the correct identification.

The association between Fusobacterium nucleatum and cancer colorectal: A systematic review and meta-analysis

INTRODUCTION

The etiological factors of colorectal cancer (CRC) are not precisely known, although genetic and environmental factors have been implicated. A possible association with Fusobacterium nucleatum may provide opportunities for an early diagnosis.

OBJECTIVE

To review studies that address the association between F. nucleatum and CRC.

METHODS

The MEDLINE PubMed database was searched using the terms «colorectal cancer» and "Fusobacterium nucleatum", retrieving publications published up to January 1 2020. Stata software was used for a meta-analysis.

RESULTS

The systematic review included 57 articles. Meta-analysis results indicated a more frequent presence of F. nucleatum in CRC tumour tissue samples in comparison to control samples of healthy tissue, with an odds ratio of 4.558 (95% CI: 3.312-6.272), and in comparison, to control samples of colorectal adenomas, with an odds ratio of 3.244 (95 % CI: 2.359-4.462).

CONCLUSION

There is a more frequent resence of F. nucleatum in the CRC. However, further studies are needed to verify this relationship.

Systematic Review of Plasmid AmpC Type Resistances in Escherichia coli and Klebsiella pneumoniae and Preliminary Proposal of a Simplified Screening Method for ampC

Beta-lactamase (BL) production is a major public health problem. Although not the most frequent AmpC type, AmpC-BL is increasingly isolated, especially plasmid AmpC-BL (pAmpC-BL). The objective of this study was to review information published to date on pAmpC-BL in Escherichia coli and Klebsiella pneumoniae, and on the epidemiology and detection methods used by clinical microbiology laboratories, by performing a systematic review using the MEDLINE PubMed database. The predictive capacity of a screening method to detect AmpC-BL using disks with cloxacillin (CLX) was also evaluated by studying 102 Enterobacteriaceae clinical isolates grown in CHROMID ESBL medium with the addition of cefepime (FEP), cefoxitin (FOX), ertapenem (ETP), CLX, and oxacillin with CLX. The review, which included 149 publications, suggests that certain risk factors (prolonged hospitalization and previous use of cephalosporins) are associated with infections by pAmpC-BL-producing microorganisms. The worldwide prevalence has increased over the past 10 years, with a positivity rate ranging between 0.1 and 40%, although AmpC was only detected when sought in a targeted manner. CMY-2 type has been the most prevalent pAmpC-BL-producing microorganism. The most frequently used phenotypic method has been the double-disk synergy test (using CLX disks or phenyl-boronic acid and cefotaxime [CTX] and ceftazidime) and the disk method combined with these inhibitors. In regard to screening methods, a 1-µg oxacillin disk with CLX showed 88.9% sensitivity, 100% specificity, 100% positive predictive value (PPV), 98.9% negative predictive value (NPV), and 98.9% validity index (VI). This predictive capacity is reduced with the addition of extended-spectrum beta-lactamases, showing 62.5% sensitivity, 100% specificity, 100% PPV, 93.5% NPV, and 94.1% VI. In conclusion, there has been a worldwide increase in the number of isolates with pAmpC-BL, especially in Asia, with CMY-2 being the most frequently detected pAmpC-BL-producing type of microorganism. Reduction in its spread requires routine screening with a combination of phenotypic methods (with AmpC inhibitors) and genotypic methods (multiplex PCR). In conclusion, the proposed screening technique is an easy-to-apply and inexpensive test for the detection of AmpC-producing isolates in the routine screening of multidrug-resistant microorganisms.

Misidentification of Phocaeicola (Bacteroides) dorei in two patients with bacteremia

Phocaeicola (Bacteroides) dorei is a Gram-negative anaerobic bacillus that is rarely isolated from human specimens. Its accurate identification can be hampered by its close taxonomic relationship with Bacteroides vulgatus. We report on two patients with bacteremia due to P. (B.) dorei, which was initially identified as B. vulgatus by MALDI-TOF MS.

Emerging Presence of Culturable Microorganisms in Clinical Samples of the Genitourinary System: Systematic Review and Experience in Specialized Care of a Regional Hospital

The detection of emerging pathogens responsible for genitourinary infections has increased with technological advances. We conducted a systematic review of publications on the involvement of these microorganisms in genitourinary samples, and we also investigated their presence and antibiotic susceptibility in samples from patients at our regional hospital (Granada, Spain). The MEDLINE database was searched up to 31 December 2020, and a cross-sectional descriptive study was performed of results obtained in urine samples and genital exudates from January 2016 through December 2019. The review highlighted the frequent involvement of Neisseria meningitidis in genital infections, while the data on other microorganisms were consistent with findings in our patient series. The emerging microorganisms most often responsible for urinary tract infections were Streptococcus bovis (58.5%) and Gardnerella vaginalis (23.6%) in females, and S. bovis (32.3%), Aerococcus urinae (18.6%), and Corynebacterium spp. (16.9%) in males; those most frequently reported in genital infections were S. viridans (36.4%) in females and C. glucuronolyticum (32.2%) and G. vaginalis (35.6%) in males. In general, emerging pathogens are resistant to conventional antibiotics such as penicillin. However, there has also been an increase in beta-lactam resistance by the S. bovis group and Corynebacterium spp. The systematic review showed that emerging microorganisms are responsible for only a small percentage of genitourinary infections but are of major clinical interest, with a predominance of the S. bovis group, G. vaginalis, Lactobacillus spp., Aerococcus spp., and Corynebacterium spp. in urine samples and of G. vaginalis and C. glucuronolyticum in genital samples. Given the increasing resistance to antibiotics empirically prescribed in patients with genitourinary infections, it is recommended to create an antibiogram in all cases.

[Infections in patients colonized with carbapenem-resistant Gram-negative bacteria in a medium Spanish city]

OBJECTIVE

Because there are few studies on the clinical implications of colonization by carbapenem-resistant gram-negative bacteria (CRB) this was analyzed in rectal smears (RS) and pharyngeals (PS) and its ability to predict infection/colonization.

METHODS

A cross-sectional, retrospective study from adult inpatients between January 2016 and December 2019 was conducted. The isolates were characterized by MicroScan and spectrometry of masses applying EUCAST 2018 cutoff points. The detection of carbapenemases was performed by PCR and Sanger sequencing; sequencies was assigned by MLST. The genetic relationship between the clinical isolates was made by pulsed field electrophoresis using the enzymes Xbal, Spel or Apal.

RESULTS

A total of 308 (86.03%) RS and 50 (13.97%) positive PS were detected, the RS had a 85% sensibility, 100% specificity, 100% positive predictive value and 97% negative predictive value. In RS, the following were isolated: 44% (n=135) Acinetobacter baumannii, 26% (n =80) Enterobacterales (20 KPC, 29 OXA-48, 22 VIM, 2 IMP, 7 NDM), 17% (n=53) Pseudomonas aeruginosa and 13% (n=40) Stenotrophomonas maltophilia. In the PS were isolated 44% (n=22) S. maltophilia, 40% (n = 20) A. baumannii, 8% (n=4) P. aeruginosa and 8% (n=4) Enterobacterales (3 VIM, 1 OXA). From the patients with simultaneous RS and PS, 41 (40.6%) had positivity in both smears, 45 (44.6%) only in RS and 15 (14.9%) only in PS. Colonization preceded infection in 81.3% (n=13) of the isolates; association between infection and colonization was found (p<0.001; χ2); and the episodes where the information was found all the isolates from the clinical samples and from the smears were similar.

CONCLUSIONS

The probability of predicting infection through the CRB colonized in different clinical samples is feasible. The RS has a major sensibility to detect colonization.

A Study in a Regional Hospital of a Mid-Sized Spanish City Indicates a Major Increase in Infection/Colonization by Carbapenem-Resistant Bacteria, Coinciding with the COVID-19 Pandemic

Bacterial resistance to antibiotics has proven difficult to control over the past few decades. The large group of multidrug-resistant bacteria includes carbapenemase-producing bacteria (CPB), for which limited therapeutic options and infection control measures are available. Furthermore, carbapenemases associate with high-risk clones that are defined by the sequence type (ST) to which each bacterium belongs. The objectives of this cross-sectional and retrospective study were to describe the CPB population isolated in a third-level hospital in Southern Spain between 2015 and 2020 and to establish the relationship between the ST and the epidemiological situation defined by the hospital. CPB were microbiologically studied in all rectal and pharyngeal swabs and clinical samples received between January 2015 and December 2020, characterizing isolates using MicroScan and mass spectrometry. Carbapenemases were detected by PCR and Sanger sequencing, and STs were assigned by multilocus sequence typing (MLST). Isolates were genetically related by pulsed-field gel electrophoresis using Xbal, Spel, or Apal enzymes. The episodes in which each CPB was isolated were recorded and classified as involved or non-involved in an outbreak. There were 320 episodes with CPB during the study period: 18 with K. pneumoniae, 14 with Klebisella oxytoca, 9 with Citrobacter freundii, 11 with Escherichia coli, 46 with Enterobacter cloacae, 70 with Acinetobacter baumannii, and 52 with Pseudomonas aeruginosa. The carbapenemase groups detected were OXA, VIM, KPC, and NDM with various subgroups. Synchronous relationships were notified between episodes of K. pneumoniae and outbreaks for ST15, ST258, ST307, and ST45, but not for the other CPB. There was a major increase in infections with CPB over the years, most notably during 2020, coinciding with the COVID-19 pandemic. This study highlights the usefulness of gene sequencing techniques to control the spread of these microorganisms, especially in healthcare centers. These techniques offer faster results, and a reduction in their cost may make their real-time application more feasible. The combination of epidemiological data with real-time molecular sequencing techniques can provide a major advance in the transmission control of these CPB and in the management of infected patients. Real-time sequencing is essential to increase precision and thereby control outbreaks and target infection prevention measures in a more effective manner.

A rare cause of bacteremia due to Porphyromonas asaccharolytica in a patient with necrotizing fasciitis

Porphyromonas species are Gram-negative anaerobic bacilli mainly involved in human periodontal diseases. We report an uncommon case of bacteremia due to P. asaccharolytica in a patient with necrotizing fasciitis. A 52-year-old woman with a history of diabetes mellitus was admitted for an extensive necrotizing lesion on the left lower limb. After she developed septic shock, two sets of blood cultures were taken. Anaerobic bottles yielded a pure culture of a microorganism initially identified as P. uenonis by MALDI-TOF MS but with a low log score, and a gene sequencing technique was therefore applied, identifying the isolate as P. asaccharolytica. Only resistance to penicillin and clindamycin was documented. Treatment with meropenem was administered, and the patient was discharged following her recovery.

Update in Diagnostics of Toscana Virus Infection in a Hyperendemic Region (Southern Spain)

The sandfly fever Toscana virus (TOSV, genus Phlebovirus, family Phenuiviridae) is endemic in Mediterranean countries. In Spain, phylogenetic studies of TOSV strains demonstrated that a genotype, different from the Italian, was circulating. This update reports 107 cases of TOSV neurological infection detected in Andalusia from 1988 to 2020, by viral culture, serology and/or RT-PCR. Most cases were located in Granada province, a hyperendemic region. TOSV neurological infection may be underdiagnosed since few laboratories include this virus in their portfolio. This work presents a reliable automated method, validated for the detection of the main viruses involved in acute meningitis and encephalitis, including the arboviruses TOSV and West Nile virus. This assay solves the need for multiple molecular platforms for different viruses and thus, improves the time to results for these syndromes, which require a rapid and efficient diagnostic approach.

[Increased infections by herpes simplex virus type 1 and polymicrobials of the genital tract, in the general population of a Spanish middle city]

Introducción

Las infecciones por genitopatógenos son un motivo de consulta frecuente en Atención Primaria y en las especialidades de Enfermedades Infecciosas, Urología, Ginecología y Dermatología. Las causas más comunes son los microorganismos oportunistas y los responsables de las infecciones de transmisión sexual asociadas a prácticas sin protección. El objetivo de este trabajo es determinar los microorganismos que causan estas infecciones en los pacientes atendidos en el Hospital Universitario Virgen de las Nieves de Granada y la sensibilidad a los antibióticos de Neisseria gonorrhoeae.

Material y métodos

Se realizó un estudio transversal y retrospectivo, en el que se incluyeron los resultados emitidos, entre enero de 2018 y diciembre de 2019, en el Laboratorio de Microbiología a partir de todos los episodios estudiados mediante procedimiento normalizados de trabajo.

Resultados:

Los microorganismos más frecuentemente detectados fueron Gardnerella vaginalis (23,81%) seguido de Candida spp. (20,9%), sobre todo en mujeres, N. gonorrhoeae (11,36%) y Ureaplasma urealyticum (11,99%), sobre todo en hombres. En multitud de ocasiones se presentaron de forma combinada. En cuanto a los virus del herpes simple, en hombres la infección por ambas especies tuvo una presencia similar (50%), mientras que en mujeres el tipo 1 fue más prevalente (76,52%). Los antibióticos más activos frente a N. gonorrhoeae fueron cefotaxima (98%) y cefixima (100%), siendo poco activo tetraciclina (39,02%).

Conclusiones

Los patógenos más frecuentes correspondieron a aquellos que han causado habitualmente infecciones en las mujeres, aunque N. gonorrhoeae fue el más frecuente en varones y las infecciones mixtas no son un hallazgo casual. Las infecciones por VHS-1 fueron más frecuentes que por VHS-2, lo cual confirma la tendencia de un cambio en la epidemiología del herpes genital.

First case of abdominal infection caused by bacteroides fluxus

Bacteroides fluxus is a Gram-negative anaerobic bacillus isolated from human faeces in healthy individuals. Until now, this bacterium had not been involved in human diseases. We report the first case of abdominal infection due to this microorganism in an elderly patient. A 76-year-old man with a history of chronic pulmonary obstructive disease presented with dyspnea, orthopnea and cough. The clinical evolution worsened with both a colonic ischemia and further diffuse peritonitis of pancreatic origin. Peritoneal fluid was obtained and the culture yielded B. fluxus in pure culture. Resistance to penicillin, amoxicillin-clavulanate, clindamycin and moxifloxacin was documented. Treatment with meropenem + linezolid was started, but the patient finally died due to a multiorganic failure.

[Etiology of urinary tract infections in our health area and susceptibility profile of the most common uropathogens.]

Adequate empirical treatment should be established for treatment urinary tract infections, considering the prevalence of the most frequent microorganisms in each geographic area and their susceptibility to different antibiotics. The objective of the study is to analyze the epidemiology of UTIs in our Health Area as well as to understand the antibiotic susceptibility of the most prevalent isolated microorganisms to guide empirical treatment. The objective was to establish a reasoned system for recommending ITU empirical therapy, based on the microorganisms causing episodes assisted in a Regional Hospital, knowing their antibiotic susceptibility. PATIENTS AND METHODS: A descriptive-retrospective study was carried out based on the results of 12,204 urine cultures of the year 2018. The overall empirical activity of the antibiotics tested was calculated, differentiating between episodes of the community and of in patients, adults and children. RESULTS: Escherichia coli was the most frequently isolated microorganism in all studied groups. The following microorganisms in frequency, in adults, were Enterococcus faecalis, Klebsiella pneumoniae and yeasts (8%). In the group of children these were Enterococcus faecalis and Proteus mirabilis. There was no difference in the activity of antibiotics against Escherichia coli, in adults or in children, of the community or in patients, with sensitivityto fosfomycin and nitrofuranto in greater than 96%; at imipenem and piperacillin-tazobactam greater than 94% and third generation cephalosporins greater than 90%. However, the overall empirical activity, without distinction by microorganism, was for fosfomycin 77.96-80.60% in adults and 92.73-94.50% in children; to prevent 77.70-78.74% in adults and 92.36-91.28% in children; for piperacillin-tazobactam of 77.57-80.03% in adults and 89.09-94.04% in children; and for cefotaxime of 53.28-54.76% in adults and 68.73-74.77% in children. CONCLUSIONS: Fosfomycin, piperacillin-tazobactam or imipenem were the best option for empirical treatment without covering all episodes in adults. Each Center must establish a reasoned profile of empirical treatment of the infection, which should also take into account risk factors for a microorganism and clinical severity.

The association between Fusobacterium nucleatum and cancer colorectal: a systematic review and meta-analysis

INTRODUCTION

The etiological factors of colorectal cancer (CRC) are not precisely known, although genetic and environmental factors have been implicated. A possible association with Fusobacterium nucleatum may provide opportunities for an early diagnosis.

OBJECTIVE

To review studies that address the association between F. nucleatum and CRC.

METHODS

The MEDLINE PubMed database was searched using the terms «colorectal cancer» and «Fusobacterium nucleatum», retrieving publications published up to January 1 2020. Stata software was used for a meta-analysis.

RESULTS

The systematic review included 57 articles. Meta-analysis results indicated a more frequent presence of F. nucleatum in CRC tumor tissue samples in comparison to control samples of healthy tissue, with an odds ratio of 4.558 (95% CI: 3.312-6.272), and in comparison, to control samples of colorectal adenomas, with an odds ratio of 3.244 (95% CI: 2.359-4.462).

CONCLUSION

There is a more frequent presence of F. nucleatum in the CRC. However, further studies are needed to verify this relationship.

The first wave of the COVID-19 epidemic in Spain was associated with early introductions and fast spread of a dominating genetic variant

The coronavirus disease 2019 (COVID-19) pandemic has affected the world radically since 2020. Spain was one of the European countries with the highest incidence during the first wave. As a part of a consortium to monitor and study the evolution of the epidemic, we sequenced 2,170 samples, diagnosed mostly before lockdown measures. Here, we identified at least 500 introductions from multiple international sources and documented the early rise of two dominant Spanish epidemic clades (SECs), probably amplified by superspreading events. Both SECs were related closely to the initial Asian variants of SARS-CoV-2 and spread widely across Spain. We inferred a substantial reduction in the effective reproductive number of both SECs due to public-health interventions (R_e < 1), also reflected in the replacement of SECs by a new variant over the summer of 2020. In summary, we reveal a notable difference in the initial genetic makeup of SARS-CoV-2 in Spain compared with other European countries and show evidence to support the effectiveness of lockdown measures in controlling virus spread, even for the most successful genetic variants.

Clinical Relevance of Antibiotic Susceptibility Profiles for Screening Gram-negative Microorganisms Resistant to Beta-Lactam Antibiotics

The increasing resistance to antibiotics is compromising the empirical treatment of infections caused by resistant bacteria. Rapid, efficient, and clinically applicable phenotypic methods are needed for their detection. This study examines the phenotypic behavior of β-lactam-resistant Gram-negative bacteria grown on ChromID ESBL medium with ertapenem, cefoxitin, and cefepime disks, reports on the coloration of colonies, and establishes a halo diameter breakpoint for the detection of carbapenemase-producing bacteria. We studied 186 β-lactam-resistant Gram-negative microorganisms (77 with extended spectrum beta lactamase (ESBL), 97 with carbapenemases, and 12 with AmpC β-lactamases (AmpC)). Susceptibility profiles of Gram-negative bacteria that produced ESBL, AmpC, and carbapenemases were similar to the expected profiles, with some differences in the response to cefepime of ESBL-producing microorganisms. Coloration values did not differ from those described by the manufacturer of ChromID ESBL medium. In the screening of carbapenemase production, inhibition halo diameter breakpoints for antibiotic resistance were 18 mm for Enterobacterales and ertapenem, 18 mm for Pseudomonas and cefepime, and 16 mm for Acinetobacter baumannii and cefepime. This innovative phenotypic approach is highly relevant to clinical laboratories, combining susceptibility profiles with detection by coloration of high-priority resistant microorganisms such as carbapenemase-producing A. baumannii, carbapenemase-producing Pseudomonas spp., and ESBL and/or carbapenemase-producing Enterobacterales.

Potential clinical use of azithromycin against gastroenteritis-causing pathogens other than Campylobacter

The activity of azithromycin against enteritis-producing agents other than Campylobacter spp. was studied. The susceptibility to azithromycin, through gradient test, of 88 clinical isolates (51 Salmonella spp., 23 Aeromonas spp., 10 Shigella sonnei and 4 Yersinia enterocolitica) for one year was studied prospectively. The results were compared with the activity of ampicillin, trimethoprim-sulfamethoxazole and ciprofloxacin by microdilution. For azithromycin, the minimum inhibitory concentration (MIC) 50 and MIC90 were 4 and 12 mg/l, respectively. Six (6.8%) isolates were simultaneously resistant to ampicillin, trimethoprim- sulfamethoxazole and ciprofloxacin, and 3 (50%) of them presented a MIC >256 mg/l. Azithromycin may be a good empirical therapeutic option for the treatment of bacterial enteritis.

Update on the Diagnosis of Sexually Transmitted Infections

Sexually transmitted infections (STIs) are one of the most frequent and universal Public Health problems. Health professionals should be aware of the possibility of STIs due to their high morbidity and the presence of sequelae. The delay in the diagnosis is one of the factors that justifies the difficulty to infections control. Diagnostic tests allow the introduction of aetiological treatment and also lead to treating symptomatic and asymptomatic patients more effectively, as well as to interrupt the epidemiological transmission chain without delay. In this review we have made an update of the main existing diagnostic methods for the more important STIs.

Clinical Findings and Antimicrobial Susceptibility of Anaerobic Bacteria Isolated in Bloodstream Infections

The objectives of this study were to report on the antimicrobial susceptibility of 141 clinically significant anaerobic bacteria isolated from bloodstream infections between January 2016 and April 2020 in a tertiary-care hospital in Granada (Spain) and to describe the main clinical features of the patients. Species identification was performed by MALDI-TOF MS (Bruker Daltonics, Billerica, MA, USA). Antimicrobial susceptibility tests were performed against penicillin, amoxicillin-clavulanic acid, imipenem, moxifloxacin, clindamycin, metronidazole, and piperacillin-tazobactam using the gradient diffusion technique and EUCAST breakpoints, except for moxifloxacin (CLSI breakpoints). The most frequent anaerobes were Bacteroides (43.9%, n = 62), Clostridium (24.1%, n = 34) and Gram-positive anaerobic cocci (GPACs) (15.6%, n = 22). Almost all tested anaerobes were susceptible to imipenem and amoxicillin-clavulanic acid, except for Bacteroides. High overall resistance rates to clindamycin were observed, especially for Gram-positive anaerobic cocci (GPACs) (54.5%) and for Bacteroides spp. (45.1%). Overall, low resistance rates to almost all antibiotics were observed for Clostridium. High resistance rates to penicillin were also observed for Gram-positive anaerobic bacilli (GPABs) (44.4%), as well as to metronidazole (22.2%), although only nine isolates were included. Antimicrobial susceptibility testing for anaerobes should always be performed in severe infections, such as those localized in the bloodstream. The information obtained contributes to selecting empirical treatments according with local data on resistance.

Breast Abscesses Caused by Anaerobic Microorganisms: Clinical and Microbiological Characteristics

The objectives of this study were to report the antimicrobial susceptibility of 35 clinically significant anaerobic bacteria isolated from breast abscesses between March 2017 and February 2020 in a tertiary hospital in Granada (Spain) and to describe key clinical features of the patients. Species identification was performed mainly by MALDI-TOF MS. Antimicrobial susceptibility tests were carried out against benzylpenicillin, amoxicillin-clavulanic acid, imipenem, moxifloxacin, clindamycin, metronidazole, and piperacillin-tazobactam using the gradient diffusion technique and European Committee on Antimicrobial Susceptibility Testing EUCAST breakpoints (except for moxifloxacin). The most frequent anaerobes were Finegoldia magna (31.4%; n = 11), Actinomyces spp. (17.1%; n = 6), Propionibacterium spp. (17.1%; n = 6), and Prevotella spp. (14.2%; n = 5). Imipenem, amoxicillin-clavulanic acid, and piperacillin-tazobactam were universally active against all genera tested. High overall resistance rates to clindamycin were observed, especially for Gram-positive anaerobic cocci (56.2%) and Gram-positive anaerobic bacilli (38.4%). High resistance rates to metronidazole were also observed for Gram-positive (76.9%) and Gram-negative anaerobic bacilli (50%). High resistance rates to moxifloxacin were found for Gram-negative anaerobic bacilli (50%) and Gram-positive anaerobic cocci (31.2%). No breast abscess cases of Bacteroides spp. were detected. Routine antimicrobial susceptibility testing for anaerobes in breast abscesses may contribute to allow empirical therapies to be selected in accordance with local data on resistant strains.

Rhodotorula dairenensis fungemia in a patient with cancer

BACKGROUND

Rhodotorula species were traditionally considered non-virulent environmental microorganisms, but are nowadays considered important human pathogens, especially in immunocompromised individuals.

CASE REPORT

We present the case of a 73 year-old man with diarrhea, anorexia and fever. In the blood analyses, both aerobic blood culture bottles yielded the growth of Rhodotorula dairenensis. The MALDI-TOF MS score was inadequate to provide an identification, which was achieved by means of molecular techniques. Treatment with an echinocandin was started, but the patient died.

CONCLUSIONS

Basidiomycetous yeast genera such as Rhodotorula can cause invasive and severe infections, e.g., fungemia, especially in patients with central venous catheter or another indwelling device.