Comparison of gradient diffusion and molecular methods using Allplex™ NG&DR assay (Seegene®) for macrolide and fluoroquinolone screening resistance in Neisseria gonorrhoeae.

Antimicrobial resistance in Neisseria gonorrhoeae (NG) is increasing worldwide. Second-line treatments with macrolides or fluoroquinolones are an option for NG infections in some cases following the STI guideline recommendations. In our study, we compared the gradient diffusion test using EUCAST 2024 breakpoints with a new molecular method using the Allplex™ NG&DR assay (Seegene®) including A2059G/C2611 mutations (23S rRNA) associated with high/moderate-level macrolide resistance and S91F mutation (gyrA) relationship with fluoroquinolone resistance in NG isolates (n = 100). We calculated the sensitivity, specificity, and correlation of the molecular test for fluoroquinolone using the gradient diffusion as the reference method. In twenty-three strains was not detected any mutation associated with macrolides or fluoroquinolone resistance. No A2059G/C2611T mutations were detected, and the S91F mutations were detected in 77 out of the 100 isolates screened. Twenty-three NG isolates were reported to be resistant to azithromycin (ECOFF: >1 mg/L), and 78 NG isolates were resistant to ciprofloxacin (MIC: >0.06 mg/L). The molecular method showed a sensitivity of 96.1% and, a specificity of 90.9% for fluoroquinolone susceptibility, but the statistical analysis between the molecular test and gradient diffusion test was not statistically significant for fluoroquinolone resistance (p = 1). Statistical analysis was not performed for macrolides because of the absence of positive RT-PCR results. According to our data, Allplex™ assay cannot replace the gradient diffusion test for macrolide resistance. However, the assay could be used to test fluoroquinolone resistance in NG isolates as a replacement for phenotypic methods.

Antimicrobial susceptibility testing of anaerobic bacteria causing bacteremia: A 13-year (2010-2022) retrospective study in a tertiary hospital.

Infections from anaerobic microorganisms result from breached mucosal barriers, posing a significant mortality risk. A retrospective study at Hospital Universitario La Paz (Madrid) from 2010 to 2022 analyzed 491 (6.17 %) anaerobic bacteremia cases out of 7956 significant bacteremia cases among 171,833 blood culture requests. Bacteroides fragilis was the most frequently isolated species (28.3 %), followed by Clostridium perfringens (13.6 %). B. fragilis showed good susceptibility to amoxicillin/ clavulanic acid (86 %), piperacillin/tazobactam (86 %), and metronidazole (87.7 %). In general, non-fragilis Bacteroides species showed low susceptibility to penicillin (7 %), amoxicillin (17.5 %), and clindamycin (64.9 %). Of our 13 non-perfringens Clostridium isolates, four exhibited resistance to penicillin and four showed resistance to clindamycin. Lactobacillus species were highly susceptible to antibiotics tested. Prevotella spp. showed low susceptibility to penicillin (20 %), amoxicillin (20 %), and clindamycin (40 %). The study contributes valuable data for monitoring and improving anaerobic bacteremia treatment.

Increase in gonococcal arthritis in Madrid, Spain, 2022-2023.

In recent years, there has been an increase in Neisseria gonorrhoeae infections in Europe and Spain. Disseminated gonococcal infection is an uncommon clinical presentation that includes gonococcal arthritis. Improved antibiotic treatment has reduced the incidence of gonococcal arthritis. However, the increase in gonococcal infections may have increased the frequency of this clinical entity in recent times. We report five cases of gonococcal arthritis in patients in a tertiary-care hospital in the northern area of Madrid (Spain) from October 2022 to October 2023. Major cases occurred in male patients with unprotected sex and polyarticular symptoms requiring hospital admission and treatment with ceftriaxone and cefixime. The use of molecular techniques has allowed the detection of a greater number of culture-negative cases of gonococcal arthritis, as well as the detection of mutations associated with resistance to fluoroquinolone for switching to oral treatment.

"Induced sputum versus gastric lavage for the diagnosis of pulmonary tuberculosis in children".

BACKGROUND: Diagnosis of pulmonary tuberculosis (PTB) is difficult in infants and young children. For microbiological confirmation of PTB children, sequential gastric lavage (GL) is recommended. Induced sputum (IS) may be an alternative or complementary tool, but the information is limited in children in developed countries. The aim of this study is to assess the safety and diagnostic yield from IS combined with GL for PTB diagnosis in non-HIV infected children. METHODS: The study involved 22 children with suspected PTB admitted to the Getafe Hospital from January 2007 to May 2011. IS and GL were performed on three consecutive days, according to a standardized protocol. In all samples, BK staining, culture and PCR were carried out, including Genotype MTBDR plus for resistance to INH-RIF (Isoniazid-Rifampin) since 2008. A preliminary analysis of an ongoing prospective study is presented. RESULTS: Median age was 72 months (range 1 month to 14 years of age). Seven (33%) were ≤ 5 years of age. Seventeen were clinically diagnosed of PTB based on positive PPD and radiological criteria. Microbiological confirmation was achieved in 10 (58.8%) by either GL or IS. M. tuberculosis was identified by GL in 8 children (47.1%) and by IS in 7 (41.2%). One infant (2 IS samples) had transient oxygen desaturation recovered spontaneously. CONCLUSIONS: IS appears to be safe and well tolerated by children for diagnosis of PTB and is more convenient. Increasing the diagnostic yield of PTB in children with PTB may be a complementary technique. Largest studies are necessary to define the role of IS in paediatric PTB.

A simple double differential centrifugation-wash procedure to rapidly obtain bacterial identification and direct antimicrobial susceptibility testing from positive blood cultures.

INTRODUCTION: This study proposes a simple and rapid method for both bacterial identification and direct antimicrobial susceptibility testing (AST) by using MALDI-TOF and a double differential centrifugation-wash procedure from positive blood cultures. METHODS: Fifty-two positive blood cultures (37 gramnegative bacilli and 15 grampositive cocci) were studied by two methods for identification and AST: a reference method, and the rapid MALDI-TOF method obtaining a purified pellet by using a double differential centrifugation procedure. RESULTS: A total of 1101 MIC values (mg/l) were interpreted according to EUCAST clinical breakpoints and compared using the two methods simultaneously. Discrepancies in 81 MIC values (7.35%) were detected. By analyzing standard parameters, we obtained 98.28% essential agreement and 92.65% categorical agreement considering all isolates tested. CONCLUSION: This method provides rapid bacterial identification and AST, offering definitive results 24-48h earlier than the conventional method (p<0.001) and improving the turnaround time in blood culture diagnostics, especially in laboratories without 24-h on-call.

Evaluation of MSP96, MBT Biotarget™ 96 and AnchorChip™ 600/96 MALDI-TOF MS target plates for direct identification of positive blood cultures.

The objective of the study was to compare the diagnostic performances of three Bruker MALDI-TOF MS target plates. A combination of two or three targets results in an increase of the identification percentage, especially in problem isolates as gram-positive cocci and yeast.

Identification of Recent Tuberculosis Exposure Using QuantiFERON-TB Gold Plus, a Multicenter Study.

We investigated whether the difference of antigen tube 2 (TB2) minus antigen tube 1 (TB1) (TB2-TB1) of the QuantiFERON-TB gold plus test, which has been postulated as a surrogate for the CD8+ T-cell response, could be useful in identifying recent tuberculosis (TB) exposure. We looked at the interferon gamma (IFN-γ) responses and differences in TB2 and TB1 tubes for 686 adults with QFT-plus positive test results. These results were compared among groups with high (368 TB contacts), low (229 patients with immune-mediated inflammatory diseases [IMID]), and indeterminate (89 asylum seekers or people from abroad [ASPFA]) risks of recent TB exposure. A TB2-TB1 value >0.6 IU·ml-1 was deemed to indicate a true difference between tubes. In the whole cohort, 13.6%, 10.9%, and 11.2% of cases had a TB2>TB1 result in the contact, IMID, and ASPFA groups, respectively (P = 0.591). The adjusted odds ratios (aORs) for an association between a TB2-TB1 result of >0.6 IU·ml-1 and risk of recent exposure versus contacts were 0.71 (95% confidence interval [CI], 0.31 to 1.61) for the IMID group and 0.86 (95% CI, 0.49 to 1.52) for the ASPFA group. In TB contact subgroups, 11.4%, 15.4%, and 17.7% with close, frequent, and sporadic contact had a TB2>TB1 result (P = 0.362). The aORs versus the close subgroup were 1.29 (95% CI, 0.63 to 2.62) for the frequent subgroup and 1.55 (95% CI, 0.67 to 3.60) for the sporadic subgroup. A TB2-TB1 difference of >0.6 IU·ml-1 was not associated with increased risk of recent TB exposure, which puts into question the clinical potential as a proxy marker for recently acquired TB infection. IMPORTANCE Contact tuberculosis tracing is essential to identify recently infected people, who therefore merit preventive treatment. However, there are no diagnostic tests that can determine whether the infection is a result of a recent exposure or not. It has been suggested that by using the QuantiFERON-TB gold plus, an interferon gamma (IFN-γ) release assay, a difference in IFN-γ production between the two antigen tubes (TB2 minus TB1) of >0.6 IU·ml-1 could serve as a proxy marker for recent infection. In this large multinational study, infected individuals could not be classified according to the risk of recent exposure based on differences in IFN-γ in TB1 and TB2 tubes that were higher than 0.6 IU·ml-1. QuantiFERON-TB gold plus is not able to distinguish between recent and remotely acquired tuberculosis infection, and it should not be used for that purpose in contact tuberculosis tracing.

Tuberculosis in the paediatric population of Madrid in the last 26 years. / Enfermedad tuberculosa en población pediátrica en Madrid en los últimos 26 años.

INTRODUCTION: Tuberculosis (TB) continues to be a serious public health problem and establishing a definitive diagnosis among children is extremely challenging. Pulmonary tuberculosis is the most prevalent form, with children under the age of 2 years being at greatest risk of severe and disseminated forms. The aim of this study was to describe TB among children in Spain in recent years. PATIENTS AND METHODS: A retrospective study of paediatric patients diagnosed with TB in two hospitals of the Community of Madrid over a 26-year period (1991-2017). Epidemiological and clinical variables, additional tests and treatments received were analysed. RESULTS: 170 children were included. The two most-affected age groups were infancy and adolescence. 42.9% of patients were immigrant children (South-America or Morocco). The main reasons for consultation were TB contact (20.6%) and fever (15.3%). At diagnosis, 61.8% of cases referred an epidemic environment, and 30.6% were asymptomatic. The Mantoux tuberculin skin test was positive in 92.2% of patients and IGRA was positive in 70.6%. Pulmonary TB was identified in 91.8% of children vs. 8.2% with extrapulmonary forms. Gastric juice culture was positive in 36.9% of cases and three strains resistant to isoniazid were isolated. All patients were cured without complications except one who died. CONCLUSIONS: Pulmonary TB continues to be the most prevalent form among children and presumptive diagnosis (symptoms consistent with positive Mantoux test or suggestive X-ray) is the most common form of diagnosis. It is important to conduct a contact investigation in order to control the spread of TB.

[Symptomatic hypercalcemia presenting as a case of isolated splenic tuberculosis]. / Hipercalcemia sintomática como forma de presentación de un caso de tuberculosis esplénica aislada.

BACKGROUND AND OBJECTIVE: To describe an unusual clinical presentation as isolated splenic tuberculosis. PATIENT AND METHODS: We report a case of isolated splenic tuberculosis, a rare form of extrapulmonary tuberculosis in an immunocompetent patient, and, as a peculiarity, debuts in the form of symptomatic hypercalcemia. RESULTS: We deeply report the clinical case and the procedures performed to exclude other diseases. We emphasize the usefulness of fine needle aspiration of the spleen to obtain microbiological samples, and the use of specific polymerase chain reaction for mycobacterias to establish the definitive diagnosis of this entity. In agreement with other authors, we chose initial medical treatment with antituberculous drugs, reserving surgery for refractory cases or in case of spontaneous splenic rupture. CONCLUSION: Hypercalcemia can be a presentation of granulomatous diseases. The isolated involvement of the spleen by mycobacterias is a rare form of extrapulmonary tuberculosis and more so in immunocompetent patients.