Prevalence of Chagas disease in Latin American pregnant women in Madrid, Spain: A multicentre cross-sectional study from 2011 to 2016.

OBJECTIVE: The aim of this study is to assess Trypanosoma cruzi infection prevalence among pregnant migrants living in Madrid according to the country of origin and to assess screening coverage in this at-risk population. METHODS: Retrospective multicentre cross-sectional study conducted from January 2011 to December 2016 in eight Madrid hospitals. Each hospital reviewed their microbiology data records to assess the screening coverage and serological diagnosis in all pregnant women coming from endemic areas. RESULTS: From 2011 to 2016, 149,470 deliveries were attended at the eight hospitals, and 11,048 pregnant women were screened for Chagas disease. Most cases (93.5%) were in women from Bolivia, who also showed the highest prevalence (12.4%, 95% confidence interval: 9.9-15.0). Pooled prevalence amongst the screened women was 2.9% (95% CI: 1.8-4.1). Chagas disease screening coverage varied greatly between centres, with a pooled mean coverage of 47% (95% CI: 37%-57%; 73% [95% CI: 63%-82%] for those centres with universal screening vs. 10% [95% CI: 6%-15%] for those with a selective screening approach; p < 0.001). CONCLUSION: Our study provides useful data for policy makers and epidemiologists in a non-endemic area without congenital Chagas screening programmes.

Pneumocystis jirovecii Pneumonia Diagnostic Approach: Real-Life Experience in a Tertiary Centre.

Pneumocystis jirovecii pneumonia (PJP) in immunocompromised patients entails high mortality and requires adequate laboratory diagnosis. We compared the performance of a real time-PCR assay against the immunofluorescence assay (IFA) in the routine of a large microbiology laboratory. Different respiratory samples from HIV and non-HIV-infected patients were included. The retrospective analysis used data from September 2015 to April 2018, which included all samples for which a P. jirovecii test was requested. A total of 299 respiratory samples were tested (bronchoalveolar lavage fluid (n = 181), tracheal aspirate (n = 53) and sputum (n = 65)). Forty-eight (16.1%) patients fulfilled the criteria for PJP. Five positive samples (10%) had only colonization. The PCR test was found to have a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 96%, 98%, 90% and 99%, compared to 27%, 100%, 100% and 87%, for the IFA, respectively. PJ-PCR sensitivity and specificity were >80% and >90% for all tested respiratory samples. Median cycle threshold values in definite PJP cases were 30 versus 37 in colonized cases (p < 0.05). Thus, the PCR assay is a robust and reliable test for the diagnosis PJP in all respiratory sample types. Ct values of ≥36 could help to exclude PJP diagnosis.

ΔF659 and F659S substitutions at the HS1 of FKS2 gene, along with E655A and W715L upstream and downstream substitutions, correlate with high ibrexafungerp MICs against Candidaglabrata.

OBJECTIVES: Ibrexafungerp is a new inhibitor of Candida spp glucan synthase. We previously set the ibrexafungerp wild-type upper limit (wtUL) against Candida glabrata. We here assessed which FKS2 gene substitutions confer an ibrexafungerp non-wild-type phenotype in C. glabrata isolates. METHODS: We studied a set of C. glabrata (n = 34) isolates showing resistance to micafungin and anidulafungin (n = 28) or only to anidulafungin (n = 6) and harbouring 10 different FKS2 gene substitutions. Antifungal susceptibility to ibrexafungerp was tested according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) E.Def 7.3.2 procedure and isolates were considered ibrexafungerp non-wild type according to the statistical wtUL (minimum inhibitory concentration [MIC] ≥2) or visual wtUL (MIC ≥4). RESULTS: Ibrexafungerp MICs against the isolates ranged from 0.06 to 4 mg/L. Four FKS2 gene substitutions (ΔF659, F659S, E655A, and W715L) were exclusively found in isolates showing an ibrexafungerp MIC above the statistical wtUL (≥2 mg/L) whereas isolates harbouring other substitutions were found to be ibrexafungerp wild type. The use of the visual wtUL (MIC ≥4 mg/L) bisected the population of isolates harbouring such substitutions. DISCUSSION: C. glabrata isolates showing an ibrexafungerp MIC ≥2 mg/L may be considered non-wild type and are prone to harbour ΔF659, F659S, E655A, and W715L substitutions at the FKS2 gene. It is worth noting that substitutions ΔF659 and F659S were located at the beginning of the HS1 of FKS2 gene of C. glabrata. The role of other substitutions on conferring a non-wild-type phenotype to ibrexafungerp is not well elucidated.

First Report of Neocucurbitaria unguis-hominis Keratitis.

Coelomycetous fungi are among the emerging causes of infections and have been involved in many kinds of infections, including keratitis and endophtalmitis. Here, we present the first case of keratitis caused by Neocucurbitaria unguis-hominis, a coelomycetous fungus belonging to the family Cucurbitariaceae. In this case report, we describe the clinical presentation of a 56-year-old woman, a regular contact lens wearer, who was treated for pain in her right eye and fixed spot vision after an injury with plant debris. On examination, a corneal ulcer was observed, the foreign body was removed, and topical eye-drop therapy was started. After an initial improvement, the patient returned three weeks later due to a recurrence of discomfort in her right eye, observing the persistence of the corneal ulcer. Corneal scrapings were taken for culture, growing a filamentous fungus after seven days, which was identified by sequencing the fungal internal transcribed spacer region. It should be noted that microbiological identification of the coelomycetes in the clinical laboratory is not easy because of their difficulty in sporulating, making molecular techniques based on the amplification and sequencing of appropriate phylogenetic markers essential. Identification of these fungi is mandatory in order to optimise treatment due to the difficulty in eradicating them with antifungal treatment, requiring surgery in 50% of cases.

Antifungal Susceptibility Testing Identifies the Abdominal Cavity as a Source of Candida glabrata-Resistant Isolates.

To identify unrecognized niches of resistant Candida isolates and compartmentalization, we retrospectively studied the antifungal susceptibility of 1,103 Candida spp. isolates from blood cultures, nonblood sterile samples, and nonsterile samples. Antifungal susceptibility was assessed by EUCAST E.Def 7.3.2; sequencing and genotyping of the fks1-2 and erg11 genes were carried out for non-wild-type isolates. Resistance compartmentalization (presence of resistant and susceptible isogenic isolates in different anatomical sites of a given patient) was studied. Clinical charts of patients carrying non-wild-type isolates were reviewed. Most isolates (63%) were Candida albicans, regardless the clinical source; Candida glabrata (27%) was the second most frequently found species in abdominal cavity samples. Fluconazole and echinocandin resistance rates were 1.5 and 1.3%, respectively, and were highest in C. glabrata. We found 22 genotypes among non-wild-type isolates, none of them widespread across the hospital. Fluconazole/echinocandin resistance rates of isolates from the abdominal cavity (3.2%/3.2%) tended to be higher than those from blood cultures (0.7%/1.3%). Overall, 15 patients with different forms of candidiasis were infected by resistant isolates, 80% of whom had received antifungals before or at the time of isolate collection; resistance compartmentalization was found in six patients, mainly due to C. glabrata. The highest antifungal resistance rate was detected in isolates from the abdominal cavity, mostly C. glabrata. Resistance was not caused by the spread of resistant clones but because of antifungal treatment. Resistance compartmentalization illustrates how resistance might be overlooked if susceptibility testing is restricted to bloodstream isolates.

Endotracheal tubes coated with a broad-spectrum antibacterial ceragenin reduce bacterial biofilm in an in vitro bench top model.

BACKGROUND: Ventilator-associated pneumonia is one of the most common nosocomial infections, caused mainly by bacterial/fungal biofilm. Therefore, it is necessary to develop preventive strategies to avoid biofilm formation based on new compounds. OBJECTIVES: We performed an in vitro study to compare the efficacy of endotracheal tubes (ETTs) coated with the ceragenin CSA-131 and that of uncoated ETTs against the biofilm of clinical strains of Pseudomonas aeruginosa (PA), Escherichia coli (EC) and Staphylococcus aureus (SA). METHODS: We applied an in vitro bench top model using coated and uncoated ETTs that were treated with three different clinical strains of PA, EC and SA for 5 days. After exposure to biofilm, ETTs were analysed for cfu count by culture of sonicate and total number of cells by confocal laser scanning microscopy. RESULTS: The median (IQR) cfu/mL counts of PA, EC and SA in coated and uncoated ETTs were, respectively, as follows: 1.00 × 101 (0.0-3.3 × 102) versus 3.32 × 109 (6.6 × 108-3.8 × 109), P < 0.001; 0.0 (0.0-5.4 × 103) versus 1.32 × 106 (2.3 × 103-5.0 × 107), P < 0.001; and 8.1 × 105 (8.5 × 101-1.4 × 109) versus 2.7 × 108 (8.6 × 106-1.6 × 1011), P = 0.058. The median (IQR) total number of cells of PA, EC and SA in coated and non-coated ETTs were, respectively, as follows: 11.0 [5.5-not applicable (NA)] versus 87.9 (60.5-NA), P = 0.05; 9.1 (6.7-NA) versus 62.6 (42.0-NA), P = 0.05; and 97.7 (94.6-NA) versus 187.3 (43.9-NA), P = 0.827. CONCLUSIONS: We demonstrated significantly reduced biofilm formation in coated ETTs. However, the difference for SA was not statistically significant. Future clinical studies are needed to support our findings.

How should microbiology laboratories interpret cultures of the sonicate of closed needleless connectors?

INTRODUCTION: Our objective was to determine whether there is a cut-off in the needleless connectors' (NCs) cultures that when combined with skin cultures it was as efficient as conventional superficial cultures to rule-out catheter colonization (CC) and catheter-related bloodstream infection (CRBSI). METHODS: During 10 months, we collected samples and then we analyzed the validity values of skin+NCs cultures for CC and CRBSI considering the best cut-off showing at least >90% of specificity to have a high negative predictive value using a ROC curve. RESULTS: We collected a total of 167 catheters. The optimal cut-off of NCs culture was 1000cfu/NC. The validity values for CC and CRBSI combining skin cultures and NCs cultures using the selected cut-off were, respectively: S, 42.9%/16.7%; SP, 83.6%/75.8%; PPV, 27.3%/2.5%; and NPV, 91.0%/96.0%. CONCLUSIONS: The combination of skin cultures and quantitative NCs cultures could be used for ruling-out CC and CRBSI.

Revisiting nocardiosis at a tertiary care institution: Any change in recent years?

OBJECTIVE: To analyse relevant changes in incidence, clinical and microbiological characteristics of nocardiosis over the last 24 years at the current institution. MATERIALS AND METHODS: The clinical records of patients with nocardiosis (2006-2018) were reviewed and then compared with a previous cohort (1995-2006). Nocardia isolates were identified by 5'-end-16S-rRNA-gene-PCR targeting the first 500 bp of the gene and sequencing. Susceptibility tests were determined by broth microdilution (CLSI guidelines). RESULTS: Forty-two patients (64.3% male) with nocardiosis were evaluated in the recent cohort: 51.2% had COPD, 43.9% were on corticosteroid therapy and 31.7% had cancer. The incidence of nocardiosis varied from 6.3 to 7.1/100,000 admissions (p = 0.62). There was a decrease in HIV patients (27% vs. 4.9%, p = 0.01) and solid organ transplantation (SOT) recipients (18.9% vs. 2 .4%, p = 0.01). Cases with pulmonary involvement had increased (70.3% vs. 90.5%, p = 0.04). Nocardia species were similar but the most common were N. cyriacigeorgica (32.4% vs. 40.5%, p = 0.49) and N. farcinica (24.3% vs. 14.3%, p = 0.39). Antibiotic resistance remained stable: cotrimoxazole (10.8% vs. 5.7%, p = 0.68), imipenem (5.4% vs. 5.6%, p = 1.0); amikacin and linezolid were 100% active. No differences were found in breakthrough nocardiosis (21.6% vs. 9.8%, p = 0.21) or related mortality (21.6% vs. 21.4%, p = 1.0). The multivariate analysis confirmed that nocardiosis caused by N. farcinica is a risk factor for poor outcome (p = 0.045). CONCLUSIONS: Nocardiosis incidence has remained stable. It mainly affected elderly patients with chronic respiratory conditions and those on corticosteroid treatment. Infections in HIV and SOT patients have practically disappeared. Pulmonary involvement remains the most common area to be affected. Nocardiosis caused by N. farcinica is apparently a risk factor for poor clinical outcome.

Etiology and Prognosis of Pneumonia in Patients with Solid Tumors: A Prospective Cohort of Hospitalized Cases.

BACKGROUND: Data on the incidence, etiology, and prognosis of non-ventilator-associated pneumonia in hospitalized patients with solid tumors are scarce. We aimed to study the characteristics of non-ventilator-associated pneumonia in hospitalized patients with solid tumors. MATERIALS AND METHODS: This was a prospective noninterventional cohort study of pneumonia in patients hospitalized in an oncology ward in a tertiary teaching hospital. Pneumonia was defined according to the American Thoracic Society criteria. Patients were followed for 1 month after diagnosis or until discharge. Survivors were compared with nonsurvivors. RESULTS: A total of 132 episodes of pneumonia were diagnosed over 1 year (9.8% of admissions to the oncology ward). They were health care-related (67.4%) or hospital-acquired pneumonia (31.8%). Lung cancer was the most common malignancy. An etiology was established in 48/132 episodes (36.4%). Knowing the etiology led to changes in antimicrobial therapy in 58.3%. Subsequent intensive care unit admission was required in 10.6% and was linked to inappropriate empirical therapy. Ten-day mortality was 24.2% and was significantly associated with hypoxia (odds ratio [OR], 2.1). Thirty-day mortality was 46.2%. The independent risk factors for 30-day mortality were hypoxia (OR, 3.3), hospital acquisition (OR, 3.1), and a performance status >1 (OR, 2.6). Only 40% of patients who died within 30 days were terminally ill. CONCLUSION: Pneumonia is a highly prevalent condition in hospitalized patients with solid tumors, even with nonterminal disease. Etiology is diverse, and poor outcome is linked to inappropriate empirical therapy. Efforts to get the empirical therapy right and reach an etiological diagnosis to subsequently de-escalate are warranted. IMPLICATIONS FOR PRACTICE: The present study shows that pneumonia is a prevalent infectious complication in patients admitted to oncology wards, with a very high mortality, even in non-terminally ill patients. Etiology is diverse, and etiological diagnosis is reached in fewer than 40% of cases in nonintubated patients. Intensive care unit admission, a marker of poor outcome, is associated with inappropriate empirical therapy. These results suggest that, to improve prognosis, a more precise and appropriate antimicrobial empirical therapy for pneumonia in patients with solid tumors is necessary, together with an effort to reach an etiological diagnosis to facilitate subsequent de-escalation.

Can vancomycin lock therapy extend the retention time of infected long-term catheters?

We assessed the success rate of vancomycin catheter lock therapy (VLT) in combination with systemic antimicrobials in patients with staphylococcal catheter-related bloodstream infection (C-RBSI). Over a 6-year period, we retrospectively collected clinical and microbiological data from patients with long-term central venous catheters and staphylococcal C-RBSI who were treated with systemic antimicrobials and VLT. We then assessed the success rate of VLT based on two criteria: 1) catheter retention time> 3 months and 2) catheter in place until end of use. We found 217 staphylococcal C-RBSI episodes, 115 (53.0%) of which were managed with conservative therapy. Of these, 76 (66.1%) were treated with VLT (85.5% coagulase-negative staphylococci and 14.5% Staphylococcus aureus). The success rate of VLT was 42.1% with criterion 1 and 71.1% with criterion 2. We did not find statistically significant differences between success and failure in the majority of the clinical data recorded. We only found differences for crude mortality in criterion 1 and for parenteral nutrition in criterion 2. The success of catheter retention using VLT was moderate, reaching slightly more than 70% when the catheter was kept in place until the end of use.

A multicentre analysis of Nocardia pneumonia in Spain: 2010-2016.

OBJECTIVE: To analyse all cases of Nocardia pneumonia occurring between 2010 and 2016 in five Spanish hospitals. METHODS: This was a retrospective observational analysis of clinical and microbiological data collected from 55 cases of Nocardia pneumonia. RESULTS: There were one to 20 cases per hospital and six to nine cases per year. Chronic obstructive pulmonary disease, bronchiectasis, and asthma were the main predisposing underlying respiratory conditions. Thirty-four patients were receiving systemic and/or inhaled corticosteroids prior to infection, eight had neoplasia, and six had haematological malignancies. Clinical and radiological findings were common to pneumonia of other infectious aetiologies, except for the frequent presence of nodules and cavitation. Overall, the 1-year mortality was high (38.2%), and mortality was directly related to the pulmonary disease in 15 patients (27.3%). The most frequently identified species were N. cyriacigeorgica (n=21), N. abscessus (n=8), and N. farcinica (n=5). All Nocardia isolates were susceptible to linezolid and all but two were susceptible to amikacin and trimethoprim-sulfamethoxazole. CONCLUSIONS: Nocardia pneumonia-associated mortality remains high, probably because of the debilitated status of patients in whom this pathogen is able to cause pulmonary infection.

Susceptibility of uncommon Candida species to systemic antifungals by the EUCAST methodology.

The incidence of infections by uncommon Candida species has increased in recent years, however, in vitro susceptibility data are scarce. Here we assess the susceptibility of C. krusei, C. dubliniensis, C. lusitaniae, and C. guilliermondii complex isolates (n = 120) to antifungal agents by the EUCAST methodology. C. dubliniensis proved to be the most susceptible species, similar to that of C. albicans (P < .05), whereas C. guilliermondii was the least susceptible. Two C. krusei isolates were echinocandin-resistant and harbored a point mutation (L701M) in the FKS1. Some isolates were either fluconazole-resistant (C. lusitaniae, n = 2) or fluconazole non-wild type (C. guilliermondii, n = 3).

Gradient diffusion antibiogram used directly on bronchial aspirates for a rapid diagnosis of ventilator-associated pneumonia.

Background: In patients with suspected ventilator-associated pneumonia, a rapid etiological diagnosis is crucial as incorrect or delayed treatment in the first few hours leads to a worse prognosis and a higher mortality rate. This study examines the efficacy of a rapid antibiogram on bronchial aspirates in patients with suspected ventilator-associated pneumonia (VAP). Methods: The direct gradient diffusion susceptibility testing method (GDM) on respiratory samples was compared with a standard broth microdilution method (BMD) after quantitative cultures in patients with suspicion of VAP. Samples were preselected by Gram staining (for good quality microbiological samples with a predominant single bacterial morphotype). The antibiotics tested were ceftazidime, ceftobiprole, ceftolozane-tazobactam, meropenem, doripenem, and tedizolid. Results: Over a 16-month study period, 445 bronchial aspirate samples were selected from 1376 samples received at our laboratory from 672 adult patients. By direct plating on Mueller-Hinton agar, we recovered 504 (95.5%) of the 528 microorganisms identified by the standard semiquantitative method. Antimicrobial susceptibility testing by GDM was compared with the BMD method in 472 strains (216 Enterobacteriaceae, 138 P. aeruginosa and 118 S. aureus.) and 1652 individual microorganism-antimicrobial agent combinations. There was total agreement between both methods in 98% of combinations. The Kappa index between both techniques was excellent (over 80%). There was only one potential major error for P. aeruginosa susceptibility to ceftazidime. Conclusions: The six GDM strips directly placed on plated bronchial aspirates obtained from patients with a suspicion of VAP provided accurate and reliable susceptibility results within 24 h.

Prevalence of submicroscopic malaria infection in immigrants living in Spain.

BACKGROUND: The importance of submicroscopic malaria infections in high-transmission areas could contribute to maintain the parasite cycle. Regarding non-endemic areas, its importance remains barely understood because parasitaemia in these afebrile patients is usually below the detection limits for microscopy, hence molecular techniques are often needed for its diagnosis. In addition to this, the lack of standardized protocols for the screening of submicroscopic malaria in immigrants from endemic areas may underestimate the infection with Plasmodium spp. The aim of this study was to assess the prevalence of submicroscopic malaria in afebrile immigrants living in a non-endemic area. METHODS: A prospective, observational, multicentre study was conducted. Afebrile immigrants were included, microscopic observation of Giemsa-stained thin and thick blood smears, and two different molecular techniques detecting Plasmodium spp. were performed. Patients with submicroscopic malaria were defined as patients with negative blood smears and detection of DNA of Plasmodium spp. with one or both molecular techniques. Demographic, clinical, analytical and microbiological features were recorded and univariate analysis by subgroups was carried out with STATA v15. RESULTS: A total of 244 afebrile immigrants were included in the study. Of them, 14 had a submicroscopic malaria infection, yielding a prevalence of 5.7% (95% confidence interval 3.45-9.40). In 71.4% of the positive PCR/negative microscopy cases, Plasmodium falciparum alone was the main detected species (10 out of the 14 patients) and in 4 cases (28.6%) Plasmodium vivax or Plasmodium ovale were detected. One patient had a mixed infection including three different species. CONCLUSIONS: The prevalence of submicroscopic malaria in afebrile immigrants was similar to that previously described in Spain. Plasmodium vivax and P. ovale were detected in almost a third of the submicroscopic infections. Screening protocols for afebrile immigrants with molecular techniques could be useful for a proper management of these patients.

Fatal disseminated infection by Gymnascella hyalinospora in a heart transplant recipient.

We report the first case of disseminated infection by Gymnascella hyalinospora in a solid organ transplant recipient. This case highlights the role of low-virulence environmental molds as an emerging cause of breakthrough invasive fungal infection in immunocompromised hosts. Nosocomial strategies of infection control including antimicrobial stewardship and advances on fast diagnostic methods are strongly encouraged to improve patient prognosis.

Evaluation of the Alfred™ turbidity monitoring system (Alifax®) following sonication in the diagnosis of central venous catheter colonization.

The conventional diagnostic techniques for catheter colonization (CC) take at least 48 h to yield results. Therefore, new diagnostic procedures that speed up the time necessary for results are needed. Our main objective was to assess the efficacy of the combination of sonication, turbidity monitoring, and MALDI-TOF to detect CC and catheter-related bloodstream infection (C-RBSI). For 1 year, we assessed central venous catheter (CVC) tips that arrived at the microbiology laboratory from adult patients admitted to our institution. CVC tips were cut, inoculated into 2.5 ml of BHI, and sonicated for 1 min. The suspension was then processed using Gram stain, quantitative culture (gold standard), and preincubation on the Alfred™ system. We analyzed the validity values of our new diagnostic approach for prediction of CC and C-RBSI and compared them with those of the gold standard. We collected a total of 167 catheters, 33 (19.8%) of which were colonized. We confirmed 21 episodes of C-RBSI. The distribution of microorganisms in colonized CVCs was as follows: Gram-positive, 68.4%; Gram-negative, 5.3%; and yeasts, 26.3%. The validity values for CC and C-RBSI using the new procedure were as follows: S, 39.4%/61.9%; Sp, 100%/100%; PPV, 100%/100%; and NPV, 87.0%/94.8%. The combination of sonication with a pre-incubation period based on turbidity monitoring using the Alfred™ system followed by MALDI-TOF proved to be a useful tool that was faster than conventional culture for ruling out C-RBSI. Future studies are needed to assess the clinical and economic impact of this diagnostic approach.

Study of the diagnostic accuracy of microbiological techniques in the diagnosis of malaria in the immigrant population in Madrid.

BACKGROUND: Malaria is currently the most important human parasitic disease in the world responsible for high morbidity and mortality. Appropriate diagnostic methods are essential for early detection. Microscopy examination remains the gold standard, although molecular techniques have higher sensitivity and are very useful in cases of low parasitaemia and mixed infections. The objective of this study was to evaluate a new commercial molecular diagnostic technique. METHODS: A prospective, observational, multicentre study was performed between January 2015 and April 2017. All participants were immigrants from malaria-endemic areas, who were divided into two groups: asymptomatic group and symptomatic. Samples from both groups were evaluated by a rapid diagnostic test (ImmunoQuick® Malaria + 4 RDT), microscopy examination, and two commercial molecular malaria tests (FTD Malaria and FTD Malaria Differentiation), then compared against an in-house reference PCR technique. RESULTS: In all, 250 patients were included: 164 (65.6%) in the asymptomatic group, and 86 (34.4%) in the symptomatic group. There were seven cases of asymptomatic parasitaemia (prevalence = 2.8%) that were detected only by molecular methods. In the symptomatic group, there were seven cases of submicroscopic malaria. The main species detected was Plasmodium falciparum (96.6%). The commercial molecular technique had higher sensitivity than the other methods (S = 96%) and a high rate of concordance with the in-house reference PCR technique (Kappa score = 0.93). CONCLUSIONS: The molecular techniques, although slower than microscopy, have adequate diagnostic accuracy and are very useful for the detection of P. falciparum in cases with low parasitaemia.

Corrigendum to "sonicating multi-lumen sliced catheter tips after the roll-plate technique improves the detection of catheter colonization in adults" [J. Microbiol. Methods 122 (2016) 20-22].

The Maki technique is the standard method for detecting catheter tip (CT) colonization. However, some "multi-lumen" catheters finish in a vaulted fornix and end at different distances from the CT. Therefore, we compared the traditional Maki technique with the sonication method using several cross-cut fragments of the CT. Our objective was to assess the yield of the Maki technique followed by sonication in the detection of adult CT colonization and catheter-related bloodstream infection (C-RBSI). For 3months, we prospectively performed CT cultures of polyurethane catheters from adult patients admitted to our institution. First, we performed CT culture using the Maki technique on blood agar plates and then sonicated small fragments of CTs in 5ml of BHI followed by culture of 100µl of the sonicate. We included a total of 252 CVCs, with overall colonization and C-RBSI rates of 14.3% (36/252) and 5.9% (15/252). Of the 36 colonized CVCs, 21 (58.3%) were detected both by Maki and sonication, 6 (16.7%) were detected only by Maki technique, and 9 (25.0%) only by sonication method. Among 15 episodes with concomitant bacteremia, both techniques were positive and concordant in 11 cases (73.3%) and in 4 cases (26.7%) sonication was the only positive technique. Our study shows that both techniques are complementary. We recommend sonicating fragments of the CT from patients with bacteremia of unknown origin and a negative CT culture by the Maki technique.