Mini-laparoscopy as a diagnostic tool for abdominal tuberculosis: a retrospective series of 29 cases.

OBJECTIVES: Abdominal tuberculosis (TB) is a "great mimic," and diagnosis remains challenging even for experienced clinicians. While mini-laparoscopy has already been demonstrated to be an efficient diagnostic tool for a variety of diseases, we aimed to demonstrate the feasibility of this technique in diagnosing abdominal TB. METHODS: We retrospectively included patients who underwent mini-laparoscopy at the University Medical Center Hamburg-Eppendorf between April 2010 and January 2022 for suspected abdominal TB. Demographic, clinical, and laboratory data, radiological findings as well as macroscopic, histopathologic, and microbiologic results were analyzed by chart review. RESULTS: Out of 49 consecutive patients who underwent mini-laparoscopy for suspected abdominal TB, the diagnosis was subsequently confirmed in 29 patients (59%). Among those, the median age was 30 years (range 18-86 years) and the majority were male (n = 22, 76%). Microbiological diagnosis was established in a total of 16 patients. The remaining patients were diagnosed with abdominal TB either by histopathological detection of caseating granulomas (n = 3), or clinically by a combination of typical presentation, mini-laparoscopic findings, and good response to anti-tuberculous treatment (n = 10). Bleeding from the respective puncture site occurred in 19 patients (66%) and either resolved spontaneously or was arrested with argon plasma coagulation alone (n = 10) or in combination with fibrin glue (n = 1). Minor intestinal perforation occurred in 2 patients and was treated conservatively. CONCLUSIONS: Mini-laparoscopy is a useful and safe modality for the diagnosis of abdominal TB.

Comparison of four diagnostic criteria for invasive pulmonary aspergillosis-A diagnostic accuracy study in critically ill patients.

BACKGROUND: In the absence of lung biopsy, there are various algorithms for the diagnosis of invasive pulmonary aspergillosis (IPA) in critically ill patients that rely on clinical signs, underlying conditions, radiological features and mycology. The aim of the present study was to compare four diagnostic algorithms in their ability to differentiate between probable IPA (i.e., requiring treatment) and colonisation. METHODS: For this diagnostic accuracy study, we included a mixed ICU population with a positive Aspergillus culture from respiratory secretions and applied four different diagnostic algorithms to them. We compared agreement among the four algorithms. In a subgroup of patients with lung tissue histopathology available, we determined the sensitivity and specificity of the single algorithms. RESULTS: A total number of 684 critically ill patients (69% medical/31% surgical) were included between 2005 and 2020. Overall, 79% (n = 543) of patients fulfilled the criteria for probable IPA according to at least one diagnostic algorithm. Only 4% of patients (n = 29) fulfilled the criteria for probable IPA according to all four algorithms. Agreement among the four diagnostic criteria was low (Cohen's kappa 0.07-0.29). From 85 patients with histopathological examination of lung tissue, 40% (n = 34) had confirmed IPA. The new EORTC/MSGERC ICU working group criteria had high specificity (0.59 [0.41-0.75]) and sensitivity (0.73 [0.59-0.85]). CONCLUSIONS: In a cohort of mixed ICU patients, the agreement among four algorithms for the diagnosis of IPA was low. Although improved by the latest diagnostic criteria, the discrimination of invasive fungal infection from Aspergillus colonisation in critically ill patients remains challenging and requires further optimization.

Clinical characteristics and outcomes of invasive Lomentospora prolificans infections: Analysis of patients in the FungiScope® registry.

OBJECTIVES: Invasive fungal infections caused by Lomentospora prolificans are associated with very high mortality rates and can be challenging to treat given pan-drug resistance to available antifungal agents. The objective of this study was to describe the clinical presentation and outcomes in a cohort of patients with invasive L prolificans infections. METHODS: We performed a retrospective review of medical records of patients with invasive L prolificans infection in the FungiScope® registry of rare invasive fungal infections. Patients diagnosed between 01 January 2008 and 09 September 2019 were included in for analysis. RESULTS: The analysis included 41 patients with invasive L prolificans infection from eight different countries. Haematological/oncological malignancies were the most frequent underlying disease (66%), disseminated infection was frequent (61%), and the lung was the most commonly involved organ (44%). Most infections (59%) were breakthrough infections. Progression/deterioration/treatment failure was observed in 23/40 (58%) of patients receiving antifungal therapy. In total, 21/41 (51%) patients, and 77% of patients with underlying haematological/oncological malignancy, had a fatal outcome attributed to invasive fungal infection. Combination antifungal therapy was frequent (24/40) and associated with improved survival. In particular, treatment regimens including terbinafine were significantly associated with higher treatment success at final assessment (P = .012), with a positive trend observed for treatment regimens that included voriconazole (P = .054). CONCLUSIONS: Lomentospora prolificans infections were associated with mortality rates of 77% and above in patients with underlying haematological/oncological malignancies and those with disseminated infections. While combination therapy is the preferred option for now, the hope lies with novel antifungals currently under development.

Fatal renal mucormycosis with Apophysomyces elegans in an apparently healthy male.

Mucor is an angioinvasive fungus that was reported mainly in immunocompromised patients. It usually presents as rhino-orbital, pulmonary, gastrointestinal, and disseminated disease. Isolated renal mucormycosis is an extremely rare infection in immunocompetent patients and is associated with high fatality rate. Early diagnosis, prompt antifungal treatment, and surgery give the patient the best chance for cure and survival. We describe herein a case of renal zygomycosis caused by Apophysomyces elegans (A. elegans) in an immunocompetent host. To the best of our knowledge, this is the first case of renal A. elegans to be reported from Qatar and the Middle East.

Insufficient sensitivity of laser desorption-time of flight mass spectrometry-based detection of hemozoin for malaria screening.

Laser desorption-time of flight (LD-TOF) mass spectrometry-based detection of hemozoin was assessed for its performance characteristics as a rapid screening test for malaria. In spite of good specificity of >95%, poor sensitivity of 80.2% for microscopically positive samples makes the easy-to-apply and rapid approach unsuitable for the routine diagnostic setting.

Sub-inhibitory tigecycline concentrations induce extracellular matrix binding protein Embp dependent Staphylococcus epidermidis biofilm formation and immune evasion.

Biofilm-associated Staphylococcus epidermidis implant infections are notoriously reluctant to antibiotic treatment. Here we studied the effect of sub-inhibitory concentrations of penicillin, oxacillin, vancomycin, daptomycin, linezolid and tigecycline on S. epidermidis 1585 biofilm formation, expression of extracellular matrix binding protein (Embp) and potential implications for S. epidermidis - macrophage interactions. Penicillin, vancomycin, daptomycin, and linezolid had no biofilm augmenting effect at any of the concentrations tested. In contrast, at sub-inhibitory concentrations tigecycline and oxacillin exhibited significant biofilm inducing activity. In S. epidermidis 1585, SarA is a negative regulator of giant 1 MDa Embp, and down regulation of sarA induces Embp-dependent assembly of a multi-layered biofilm architecture. Dot blot immune assays, confocal laser scanning microscopy, and qPCR showed that under biofilm inducing conditions, tigecycline augmented embp expression compared to the control grown without antibiotics. Conversely, expression of regulator sarA was suppressed, suggesting that tigecycline exerts its effects on embp expression through SarA. Tigecycline failed to induce biofilm formation in embp transposon mutant 1585-M135, proving that under these conditions Embp up-regulation is necessary for biofilm accumulation. As a functional consequence, tigecycline induced biofilm formation significantly impaired the up-take of S. epidermidis by mouse macrophage-like cell line J774A.1. Our data provide novel evidence for the molecular basis of antibiotic induced biofilm formation, a phenotype associated with inherently increased antimicrobial tolerance. While this could explain failure of antimicrobial therapies, persistence of S. epidermidis infections in the presence of sub-inhibitory antimicrobials is additionally propelled by biofilm-related impairment of macrophage-mediated pathogen eradication.

Does galactomannan testing increase diagnostic accuracy for IPA in the ICU? A prospective observational study.

BACKGROUND: An algorithm for distinguishing invasive pulmonary aspergillosis (IPA) in critically ill patients (AspICU) has been proposed but not tested. METHODS: This was a prospective observational study applying the AspICU protocol to patients with positive Aspergillus culture (PAC group) and those with negative aspergillus culture but positive galactomannan test in respiratory tract samples (only positive galactomannan (OPG group)). Patients underwent a standardized diagnostic workup with bronchoscopy, computed tomography (CT), and galactomannan determination in serum and bronchoalveolar lavage fluid (BALF). RESULTS: We included 85 patients in the study. Of these, 43 had positive aspergillus cultures and 42 patients had only a positive galactomannan test. There were no statistically significant differences in baseline characteristics, underlying conditions or ICU scores between the two groups. The galactomannan titre in BALF was significantly higher in the positive aspergillus culture (PAC) group (enzyme immunoassay (EIA) 5.9, IQR 3.2-5.7) than in the OPG group (EIA 1.7, IQR 0.9-4.5) (p < 0.001). Classic features of IPA were detected on CT in 37.5 % and 36.6 % of patients in the PAC and OPG groups, respectively. There were no statistically significant differences between the PAC and the OPG group in relation to AspICU or European Organization for the Research and Treatment of Cancer (EORTC) criteria. A positive aspergillus culture was a stronger trigger for initiating antimycotic treatment than positive BALF galactomannan: 88.4 % of patients in the PAC group were regarded by clinicians as having IPA and received antimycotic treatment as opposed to 59.5 % in the OPG group (p = 0.002). The 180-day mortality was 58.1 % in the PAC group and 59.5 % in the OPG group. CONCLUSIONS: The inclusion of BALF galactomannan as an additional entry criterion for the AspICU clinical algorithm could increase the diagnostic sensitivity for IPA in ICU patients. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (registration number NCT01866020 ) on 27 May 2013.

cyp51A-Based mechanisms of Aspergillus fumigatus azole drug resistance present in clinical samples from Germany.

Since the mid-1990s, a steady increase in the occurrence of itraconazole-resistant Aspergillus fumigatus isolates has been observed in clinical contexts, leading to therapeutic failure in the treatment of aspergillosis. This increase has been predominantly linked to a single allele of the cyp51A gene, termed TR/L98H, which is thought to have arisen through the use of agricultural azoles. Here, we investigated the current epidemiology of triazole-resistant A. fumigatus and underlying cyp51A mutations in clinical samples in Germany. From a total of 527 samples, 17 (3.2%) showed elevated MIC0 values (the lowest concentrations with no visible growth) for at least one of the three substances (itraconazole, voriconazole, and posaconazole) tested. The highest prevalence of resistant isolates was observed in cystic fibrosis patients (5.2%). Among resistant isolates, the TR/L98H mutation in cyp51A was the most prevalent, but isolates with the G54W and M220I substitutions and the novel F219C substitution were also found. The isolate with the G54W substitution was highly resistant to both itraconazole and posaconazole, while all others showed high-level resistance only to itraconazole. For the remaining six isolates, no mutations in cyp51A were found, indicating the presence of other mechanisms. With the exception of the strains carrying the F219C and M220I substitutions, many itraconazole-resistant strains also showed cross-resistance to voriconazole and posaconazole with moderately increased MIC0 values. In conclusion, the prevalence of azole-resistant A. fumigatus in our clinical test set is lower than that previously reported for other countries. Although the TR/L98H mutation frequently occurs among triazole-resistant strains in Germany, it is not the only resistance mechanism present.

Staphylococcus epidermidis uses distinct mechanisms of biofilm formation to interfere with phagocytosis and activation of mouse macrophage-like cells 774A.1.

Assembly of adherent biofilms is the key mechanism involved in Staphylococcus epidermidis virulence during device-associated infections. Aside from polysaccharide intercellular adhesin (PIA), the accumulation-associated protein Aap and the extracellular matrix binding protein Embp act as intercellular adhesins, mediating S. epidermidis cell aggregation and biofilm accumulation. The aim of this study was to investigate structural features of PIA-, Aap-, and Embp-mediated S. epidermidis biofilms in more detail and to evaluate their specific contributions to biofilm-related S. epidermidis immune escape. PIA-, Embp-, and Aap-mediated biofilms exhibited substantial morphological differences. Basically, PIA synthesis induced formation of macroscopically visible, rough cell clusters, whereas Aap- and Embp-dependent biofilms preferentially displayed a smooth layer of aggregated bacteria. On the microscopic level, PIA was found to form a string-like organized extracellular matrix connecting the bacteria, while Embp produced small deposits of intercellular matrix and Aap was strictly localized to the bacterial surface. Despite marked differences, S. epidermidis strains using PIA, Aap, or Embp for biofilm formation were protected from uptake by J774A.1 macrophages, with similarly efficiencies. In addition, compared to biofilm-negative S. epidermidis strains, isogenic biofilm-forming S. epidermidis induced only a diminished inflammatory J774A.1 macrophage response, leading to significantly (88.2 to 88.7%) reduced NF-κB activation and 68.8 to 83% reduced interleukin-1ß (IL-1ß) production. Mechanical biofilm dispersal partially restored induction of NF-κB activation, although bacterial cell surfaces remained decorated with the respective intercellular adhesins. Our results demonstrate that distinct S. epidermidis biofilm morphotypes are similarly effective at protecting S. epidermidis from phagocytic uptake and at counteracting macrophage activation, providing novel insights into mechanisms that could contribute to the chronic and persistent course of biofilm-related S. epidermidis foreign material infections.

The giant extracellular matrix-binding protein of Staphylococcus epidermidis mediates biofilm accumulation and attachment to fibronectin.

Virulence of nosocomial pathogen Staphylococcus epidermidis is essentially related to formation of adherent biofilms, assembled by bacterial attachment to an artificial surface and subsequent production of a matrix that mediates interbacterial adhesion. Growing evidence supports the idea that proteins are functionally involved in S. epidermidis biofilm accumulation. We found that in S. epidermidis 1585v overexpression of a 460 kDa truncated isoform of the extracellular matrix-binding protein (Embp) is necessary for biofilm formation. Embp is a giant fibronectin-binding protein harbouring 59 Found In Various Architectures (FIVAR) and 38 protein G-related albumin-binding (GA) domains. Studies using defined Embp-positive and -negative S. epidermidis strains proved that Embp is sufficient and necessary for biofilm formation. Further data showed that the FIVAR domains of Embp mediate binding of S. epidermidis to solid-phase attached fibronectin, constituting the first step of biofilm formation on conditioned surfaces. The binding site in fibronectin was assigned to the fibronectin domain type III12. Embp-mediated biofilm formation also protected S. epidermidis from phagocytosis by macrophages. Thus, Embp is a multifunctional cell surface protein that mediates attachment to host extracellular matrix, biofilm accumulation and escape from phagocytosis, and therefore is well suited for promoting implant-associated infections.