Invasive aspergillosis (IA) remains a common cause of both direct and contributable mortality in patients with hematologic malignancies (HM). Given the advances in antifungal management, it would be important to assess IA-attributable mortality (AM) and contributable mortality (CM), in addition to overall mortality (OM). We retrospectively reviewed the records of 76 consecutive HM patients with proven/probable culture-positive IA (MSG/EORTC criteria) from 2015 to 2021. Death causality was adjudicated based on published criteria. AM was defined as death “due to” IA, while CM as death “due to” and “with” IA. OM encompassed death from any cause. Mortality rates and death causalities were evaluated at 2-, 4-, 6-, and 12-week intervals following IA diagnosis. A multivariate competing risk analysis was performed to identify independent risk factors for 6-week AM, with other death causalities as the competing event. To increase diagnostic accuracy, we excluded culture-negative, Aspergillus galactomannan (GM) positive cases, as GM can be produced by other hyalohyphomycetes. The median patient age was 60 years (61%). Lymphoma and multiple myeloma (L/MM) were the most common HM (40, 53%). The remaining patients had active leukemia. Twenty-nine patients (38%) had prior stem cell transplantation, and 10 (13%) had graft-versus-host disease. Aspergillus fumigatus was the most common species (47%). Six and 12-week mortality rates were 18.7% and 22.7% for AM, 42.7% and 49.3% for CM, and 45.3% and 53.3% for OM, respectively. Notably, 2-week OM was 27.6%. Lack of neutrophil recovery was the only independent risk factor for 6-week AM on multivariate analysis (OR=4.2, p=0.006). Our findings reflect the modern reality of culture-documented IA, occurring mostly in HM patients with heavily pretreated L/MM not routinely receiving mold-active prophylaxis, and in those with active leukemia. In this real-life contemporary HM population, culture-positive IA was associated with high cumulative OM and CM. Understanding AM and CM rates could lead to more accurate sample size estimations in clinical mycology trials. Such trials should be pragmatic and assess antifungal failure at an earlier time point than the traditional 4-week mark post-diagnosis. Dimitrios P. Kontoyiannis, MD, AbbVie, Inc: Advisory Board Participation|Astellas: Grant/Research Support|Basilea: Advisor/Consultant|Cidara, Inc: Advisory Board Participation|F2G, Inc: Advisor/Consultant|Gilead: Advisor/Consultant|Gilead: Grant/Research Support|Knight, Inc: Honoraria|Pfizer: Advisor/Consultant|Scynexis: Advisor/Consultant|TTF Pharmaceuticals, Inc: Advisor/Consultant|US-Israel Binational Sci Foundation: Grant/Research Support
BACKGROUND:Antimicrobial resistance (AMR) continues to threaten modern infectious diseases practice. Antimicrobial stewardship programmes (ASPs) remain central to optimizing antimicrobial use, yet stewardship has become increasingly challenging because of rising clinical complexity, expanding data sources, and persistent workforce and analytic constraints. Artificial intelligence (AI) may strengthen stewardship by integrating clinical, microbiologic, and contextual data to support more timely and individualized decision-making. OBJECTIVES:To review current applications of AI in antimicrobial stewardship, with emphasis on resistance prediction and risk stratification, empiric therapy selection, diagnostic stewardship, antimicrobial optimization, and implementation challenges in clinical practice. SOURCES:Relevant studies evaluating AI and machine-learning approaches for AMR prediction, diagnostic stewardship, antimicrobial optimization, and clinical implementation were reviewed. CONTENT:AI-based models have been developed to predict AMR and identify patients at risk for multidrug-resistant infections using electronic health record data. These approaches may support empiric therapy selection and patient-level risk stratification, although important methodological limitations remain, including heterogeneous prediction targets, data leakage, and limited external validation. AI applications also extend to diagnostic stewardship, including optimization of blood culture use, rationalization of molecular diagnostics, and support for interpretation of microbiologic results. In the therapeutic phase, AI may support de-escalation, intravenous-to-oral conversion, duration-of-therapy reassessment, and prioritization of stewardship review, aligning clinical decisions with antimicrobial stewardship goals. However, successful implementation depends not only on model performance but also on effective integration into clinical workflows, interpretability, governance, and clinician uptake. IMPLICATIONS:AI has the potential to enhance antimicrobial stewardship by enabling more precise, scalable, and workflow-integrated decision support. Future work should prioritize prospective and multicentre evaluation, careful implementation in routine care, and governance frameworks that address safety, transparency, equity, and clinician oversight. AI should be viewed as a tool to augment ASP expertise rather than replace clinical judgement.
Given competing death causalities among hematological malignancy patients with invasive aspergillosis (IA), we assessed IA-attributable, contributable, and all-cause mortalities in patients with culture-confirmed IA. Although attributable mortality decreased, contributable and all-cause mortalities remained high. Our data suggest that improving survival would require host augmentation, in addition to improved antifungals.
Mold-active prophylaxis has reduced the incidence of invasive pulmonary aspergillosis (IPA) in patients with hematological malignancies (HMs), but breakthrough IPA (Bt-IPA) is increasingly encountered. Therefore, we studied determinants of Bt-IPA risk and its prognostic significance. We retrospectively reviewed culture-positive proven/probable IPA cases in HM patients at MD Anderson Cancer Center (2016–2021). Bt-IPA and non-Bt-IPA cases were compared to characterize risk factors, clinical presentation, and outcomes. Independent predictors of 42-day all-cause mortality were assessed using propensity score-adjusted Cox regression. Among 118 IPA cases, 50 (42.4%) were Bt-IPA. Bt-IPA was associated with acute leukemia/myelodysplastic syndrome, active HM, severe neutropenia (<100/mm3), and graft-versus-host diseases. Uncommon Aspergillus species (non-fumigatus, flavus, terreus, or niger) were more frequent in Bt-IPA than non-Bt-IPA (20.4% vs. 4.8%, p = 0.010). Forty-two-day mortality was higher in Bt-IPA (65.3% vs. 37.3%, p = 0.003), but Bt-IPA itself was not an independent predictor or mortality (p = 0.064), which was instead driven by neutropenia (p = 0.020) and hypoalbuminemia (p = 0.002). In conclusion, Bt-IPA accounted for nearly half of contemporary IPA cases and was linked to host-related risk factors and the recovery of uncommon Aspergillus species. Although not an independent prognostic predictor, Bt-IPA reflected poor host status. Thus, early diagnosis, immune enhancement strategies, and effective first-in-class antifungals may improve outcomes.
Abstract Background Historically cancer patients (pts) are considered to be at an increased risk of Listeria monocytogenes infection (listeriosis, LT), especially those with ongoing chemotherapy or receipt of glucocorticoids (GCs). However, the features of this uncommon infection have not been described in contemporary cohorts of cancer pts. Methods We performed a 12-year retrospective chart review of cancer pts with LT as confirmed by positive culture from blood or other sterile clinical samples at MD Anderson Cancer Center (2011-2023). Results We identified 20 cancer pts with LT. Twelve (60%) had an underlying hematologic malignancy (Figure 1). Lymphopenia < 1000/µL (17, 85%, severe < 200/µL in 20%) and monocytopenia < 1000/µL (18, 90%, severe < 200/µL in 35%) were common at diagnosis, as well as chemotherapy (13, 65%) and GC use (11, 55%) within 30 days prior to LT diagnosis. Most (15 pts) were < 65 years old. Fever was seen in 10 pts. Vomiting/diarrhea were common (50%), while 45% of pts had headache or altered mental status. LT most often presented with bacteremia (17, 85%) and gastroenteritis (9, 45%) (Figure 2). 7/9 pts with gastroenteritis were bacteremic. Central nervous system (CNS) manifestations (meningitis, brain abscess) were documented in 2 pts who had a lumbar puncture. Focal non-CNS infections were seen in 30% of pts in unusual sites: cellulitis, abscess, endocarditis, cholangitis, urinary tract infection, and peritonitis. Of interest, 11pts (55%) had low SOFA score at presentation and were given antibiotics only after blood cultures were positive for Listeria. In fact, most pts (17, 85%) either did not receive empiric (n=11) or had inappropriate empiric antibiotics (n=6) until LT diagnosis. The 30-day mortality from LT diagnosis was 25% and correlated with high SOFA score ≥ 5 (5/8 pts, P = 0.0005). Delayed appropriate antibiotics were not significantly associated with increased 30-day mortality in this small cohort (Table 1). Conclusion Although uncommon, LT in cancer pts has pleotropic manifestations and variable morbidity, from non-bacteremic gastroenteritis to septicemia, CNS and non-CNS focal infections. Consider LT in ill cancer pts with lymphopenia/monocytopenia and recent chemotherapy or GCs, especially if they have GI symptoms, even in the absence of fever or CNS involvement. Disclosures Sebastian Wurster, MD, MSc, Astellas Pharma: Grant/Research Support|Gilead Sciences: Grant/Research Support Dimitrios P. Kontoyiannis, MD, AbbVie: Advisor/Consultant|Astellas Pharma: Advisor/Consultant|Astellas Pharma: Grant/Research Support|Astellas Pharma: Honoraria|Cidara Therapeutics: Advisor/Consultant|Gilead Sciences: Advisor/Consultant|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria|Knight: Advisor/Consultant|Merck: Advisor/Consultant|Scynexis: Advisor/Consultant
Hepatic mucormycosis is a rare but often fatal opportunistic fungal infection, primarily affecting immunocompromised patients. Herein, we report such a case from MD Anderson Cancer Center (Houston, TX, USA) and systematically review published cases in patients ≥ 19 years of age to better characterize clinical presentation, diagnostic challenges, and treatment outcomes of hepatic mucormycosis. Among the 40 identified cases (including ours), hematologic malignancies (55%) and solid organ transplantation (30%) were the most common underlying conditions. Fever (70%) and abdominal pain (63%) were the predominant symptoms. Imaging revealed multiple hepatic lesions in 72% of cases. Diagnosis was primarily based on histopathology (73%), whereas culture positivity was low (36%), underscoring the difficulty of pathogen isolation. Mucorales-active antifungal therapy was often delayed but eventually used in 85% of cases (all amphotericin B +/- Mucorales-active triazoles), while 45% underwent additional surgical intervention. Despite treatment, 1-year all-cause mortality remained high at 46%, with a trend towards lower mortality for those who underwent surgery compared to non-surgical management (35% vs. 55%, p = 0.334). These findings highlight the aggressive nature of hepatic mucormycosis and the importance of early recognition as well as the need for non-culture-based diagnostics and multimodal treatment approaches. Improved awareness and further research into optimized management strategies are crucial to improve the outcomes of this challenging infection.
Objectives Historically, patients with leukaemia and invasive fusariosis (IF) have experienced poor outcomes in the setting of persistent immunosuppression. Herein, we retrospectively reviewed the incidence, presentation and outcomes of IF that are scarcely studied in contemporary cohorts of leukaemia patients.Methods We identified adult leukaemia patients with proven or probable IF at MD Anderson Cancer Center during 2009-21. Independent risk factors for 42 day mortality after IF diagnosis were determined using a multivariable logistic regression model. Combined with historical data, the annual IF incidence density over the past 23 years was estimated using Poisson regression analysis.Results Among 140 leukaemia patients with IF (114 proven), 118 patients (84%) had relapsed/refractory leukaemia and 124 (89%) had neutropenia at IF diagnosis. One hundred patients (71%) had pulmonary IF, 88 (63%) had disseminated IF and 48 (34%) had fungaemia. Coinfections were common (55%). Eighty-nine patients (64%) had breakthrough IF to mould-active triazoles. Most patients (84%) received combination antifungal therapy. Neutrophil recovery [adjusted OR (aOR), 0.04; 95% CI, 0.01-0.14; P < 0.0001], pulmonary IF (aOR, 3.28; 95% CI, 1.11-9.70; P = 0.032) and high SOFA score (aOR, 1.91 per 1-point increase; 95% CI, 1.47-2.50; P < 0.0001) were independent predictors of 42 day mortality outcomes. From 1998 to 2021, IF incidence density increased significantly at an annual ratio of 1.03 (95% CI, 1.01-1.06; P = 0.04).Conclusions IF is predominantly seen in patients with relapsed/refractory leukaemia and increasingly seen as a breakthrough infection to mould-active triazoles. Despite frequent combination antifungal therapy, high mortality rates have persisted in patients with lasting neutropenia.
INTRODUCTION:Advances in diagnostic technologies, particularly Point-of-Care Diagnostics (POCDs), have revolutionized clinical practice by providing rapid, user-friendly, and affordable testing at or near the patient's location. POCDs have been increasingly introduced in medical mycology and hold promise to improve patient outcomes in a variety of important human fungal diseases. AREAS COVERED:This review focuses on validated POCDs, particularly lateral flow assays (LFAs), for various fungal diseases. Additionally, we discuss emerging innovative techniques such as body fluid analysis, imaging methods, loop-mediated isothermal amplification (LAMP), microfluidic systems, clustered regularly interspaced short palindromic repeats (CRISPR)-based diagnostics, and the emerging role of artificial intelligence. EXPERT OPINION:Compact and user-friendly POCDs have been increasingly introduced in medical mycology, and some of these tests (e.g. Cryptococcus and Histoplasma antigen LFAs) have become mainstream diagnostics, while others, such as LFA in invasive aspergillosis show promise to become part of our routine diagnostic armamentarium. POCDs offer immense benefits such as timely and accurate diagnostic results, reduced patient discomfort, and lower healthcare costs and might contribute to antifungal stewardship. Integrated fluidics combined with microtechnology having multiplex capabilities will be pivotal in medical mycology.
Journal Article Corrected proof Good Outcomes in Salvage Therapy of Fusariosis in Patients With Leukemia: Is It the Host or the Drug? Get access Takahiro Matsuo, Takahiro Matsuo Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA https://orcid.org/0000-0001-9389-0628 Search for other works by this author on: Oxford Academic PubMed Google Scholar Sebastian Wurster, Sebastian Wurster Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA https://orcid.org/0000-0002-7784-7256 Search for other works by this author on: Oxford Academic PubMed Google Scholar Dimitrios P Kontoyiannis Dimitrios P Kontoyiannis Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA Correspondence: D. P. Kontoyiannis, Department of Infectious Diseases, Infection Control and Employee Health, Unit 1460, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA (dkontoyi@mdanderson.org). https://orcid.org/0000-0002-8051-2940 Search for other works by this author on: Oxford Academic PubMed Google Scholar Clinical Infectious Diseases, ciad768, https://doi.org/10.1093/cid/ciad768 Published: 04 January 2024 Article history Corrected and typeset: 04 January 2024 Published: 04 January 2024
Objectives: Clinical presentation and outcomes of esophageal candidiasis (EC) in cancer patients are scarcely studied in the azole era, as is the correlation between clinical, endoscopic, and histopathological EC manifestations. Methods: We retrospectively reviewed the risk factors, clinical features, and outcomes of pathologydocumented EC cases at MD Anderson Cancer Center. We further assessed associations between presence of symptoms, standardized 4-stage endoscopic grade (Kodsi classification), histopathological data, and fluconazole treatment failure. Results: Among 323 cancer patients with EC, 89% had solid tumors, most commonly esophageal cancer (29%). Thirty-three percent of EC patients were asymptomatic. The proportion of symptomatic EC patients significantly increased with endoscopic grade (P = 0.005). Among 202 patients receiving oral fluconazole, 27 (13%) had treatment failure. Underlying esophageal disease was the only independent predictor of fluconazole treatment failure (odds ratio: 3.88, P = 0.005). Endoscopic grade correlated significantly with Candida organism burden (Correlation coefficient [rho] = 0.21, P < 0.01) and neutrophilic inflammation (rho = 0.18, P < 0.01). Candida invasion of the squamous mucosal layer was associated with treatment failure (P = 0.049). Conclusions: EC was predominantly encountered in patients with solid tumors. One-third of EC patients were asymptomatic, challenging traditional symptom-based diagnosis. The development of integrated clinicopathological scoring systems could further guide the therapeutic management of cancer patients with EC. (c) 2024 Published by Elsevier Ltd on behalf of The British Infection Association. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Ruxolitinib, a selective inhibitor of Janus kinases, is a standard treatment for intermediate/high-risk myelofibrosis (MF) but is associated with a predisposition to opportunistic infections, especially herpes zoster. However, the incidence and characteristics of invasive fungal infections (IFIs) in these patients remain uncertain. In this report, we present the case of a 59-year-old woman with MF who developed disseminated histoplasmosis after seven months of ruxolitinib use. The patient clinically improved after ten weeks of combined amphotericin B and azole therapy, and ruxolitinib was discontinued. Later, the patient received fedratinib, a relatively JAK2-selective inhibitor, without relapse of histoplasmosis. We also reviewed the literature on published cases of proven IFIs in patients with MF who received ruxolitinib. Including ours, we identified 28 such cases, most commonly due to Cryptococcus species (46%). IFIs were most commonly disseminated (39%), followed by localized lung (21%) infections. Although uncommon, a high index of suspicion for opportunistic IFIs is needed in patients receiving JAK inhibitors. Furthermore, the paucity of data regarding the optimal management of IFIs in patients treated with JAK inhibitors underscore the need for well-designed studies to evaluate the epidemiology, pathobiology, early diagnosis, and multimodal therapy of IFIs in patients with hematological malignancies receiving targeted therapies.
Objective: Unusual clinical course Background: Shewanella spp. are gram -negative facultative anaerobic, oxidase-positive, motile bacilli that are ubiquitous but commonly occur in seawater and can cause opportunistic infection. Reports on the risk factors for Shewanella infection, its severity, antibiotic susceptibility, and prognosis are limited. This report is of a 78 -year -old man with alcoholic cirrhosis presenting with bacteremia and empyema due to infection with Shewanella spp. Case Report: A 78 -year -old man with alcoholic cirrhosis (Child-Pugh B) presented to our emergency room with a high fever. He had eaten raw fish one week prior to admission. Chest computed tomography showed a right unilateral pleural effusion, and he was hospitalized with suspected empyema. Shewanella spp. was detected in the pleural effusion and blood cultures. We initiated piperacillin/tazobactam and vancomycin empirically and switched to ceftriaxone; the effusion was successfully treated using antibiotics and pleural drainage. However, on hospitalization day 53, the patient died of aspiration pneumonia. In our literature review, we extracted 125 reported cases (including our case) and found that men were disproportionately affected (81%); median age was 61.6 (56-75) years; underlying diseases included hepatobiliary disease (33%), malignancy (25%), and cardiac disease (24%); Shewanella spp. infection sites were skin and soft tissue (35%), respiratory system (18%), and hepatobiliary system (11%); and management included antibiotics (100%), drainage (16%), and debridement (16%). The survival rate was 74% with antibiotics alone. Conclusions: Our case highlights that clinicians should recognize Shewanella spp. as a cause of empyema and bacteremia in patients with liver cirrhosis, and that microbiological diagnosis with antibiotic sensitivity testing and treatment should be undertaken urgently to prevent fatal sepsis.
Abstract Background Invasive fusariosis (IF) is a severe opportunistic mold infection with poor outcomes in immunosuppressed leukemia patients (pts). Skin involvement is the second most common manifestation of IF after pneumonia. While in vitro studies have shown synergy of terbinafine (TRB) in combination with triazoles or liposomal amphotericin B (L-AMB) for a variety of fungi, including Fusarium species, clinical data are sparse. Methods We retrospectively reviewed adult leukemia pts with proven or probable IF at MD Anderson Cancer Center (Houston, TX) between 2009 and 2021 who received adjunct TRB (aTRB) for skin manifestations of IF, in view of its high bioavailability in skin and skin structures. Demographics, clinical manifestations, antifungal therapy, and outcomes were reviewed. Results Among 140 IF pts, we identified 15 pts who received aTRB (dose range: oral 250-1,000 mg/day, duration range: 3-128 days; topical cream in 1 pt) for IF with skin involvement (Table 1). Their median age was 50 (range 21-80); 14 (93%) were male. Eleven pts (73%) had acute myeloid leukemia/myelodysplastic syndrome, 14 (93%) had neutropenia (< 500/µL), and 5 (33%) had a prior hematopoietic stem cell transplant. 13 pts (87%) had disseminated skin lesions, 1 had a localized skin lesion, and 1 had onychomycosis. All 15 patients received antifungal combination therapy. In addition to aTRB, 13 pts received voriconazole + L-AMB, 1 received posaconazole + L-AMB, and 1 received isavuconazole. The median time from IF diagnosis to aTRB initiation was 8 days (range: 0-74). While skin lesions on day 42 after aTRB initiation or at the time of earlier death were improved (6 pts, 40%) or stabilized (4 pts, 27%) in two thirds of patients, the same proportion of pts (10/15, 67%) had progression of IF in sites with poor pharmacologic exposures of TRB (lungs in 7 pts, sinus in 2 pts, endophthalmitis in 1 pt). 10 out of 15 pts died by day 42 (67%) after aTRB initiation. Patient demographics and treatment outcome Table 1. Conclusion In our limited series, aTRB seemed to display site (skin only)-specific synergistic activity with other systemic antifungals in IF, which is consistent with in vitro synergistic effects and pharmacokinetic aspects of this allylamine which has high skin concentrations. However, TRB use did not affect IF outcomes that were poor in the setting of persistent immunosuppression. Disclosures Dimitrios P. Kontoyiannis, MD, MS, ScD, PhD, AbbVie: Board Member|Astellas: Grant/Research Support|Cidara: Board Member|Gilead: Grant/Research Support|Merck: Advisor/Consultant|Scynexis/MSGERC: Board Member
We retrospectively reviewed 64 cases of cancer with pulmonary legionellosis (Legionella pneumophila in 73%). Nearly all patients received Legionella-active antibiotics, yet 30-day mortality was 23%. Independent predictors of 30-day mortality were hyponatremia, bilateral lung involvement, and Sequential Organ Failure Assessment score ≥5. Lung coinfections were common (31%) but did not significantly increase mortality.
We report a case of fulminant Mucorales fungemia in a heavily immunosuppressed cancer patient with hemophagocytic lymphohistiocytosis following CD70-targeted chimeric antigen receptor T-cell therapy. Although rare, Mucorales can cause true fungemia in a broad spectrum of hosts, with a range of manifestations from isolated fungemia to fungemia being part of widely disseminated, high-burden infection.
Sialadenitis has rarely been reported in patients with infectious mononucleosis (IM). Our patient was a 22-year-old man who presented with bilateral swelling of the parotid and submandibular glands, a fever, malaise, and splenomegaly. Laboratory tests revealed an increased percentage of atypical lymphocytes in the leukocyte fraction. Serological testing for antibodies against Epstein-Barr virus (EBV) revealed an acute infection pattern. The patient was diagnosed with sialadenitis associated with IM caused by EBV infection. With symptomatic treatment, the salivary gland swelling completely resolved within a week. This case suggests that EBV-induced IM should be included in the differential diagnosis of diffuse sialadenitis with elevated atypical lymphocyte counts.
Germline pathogenic variants (PVs) in the gene encoding the GATA2 transcription factor can result in profound reductions of monocytes, dendritic cells, natural killer cells and B cells. GATA2 PVs are associated with an increased risk of myeloid malignancies and a predisposition to nontuberculous mycobacterial and human papillomavirus infections. Additionally, invasive fungal infections (IFIs) have been reported in individuals with GATA2 PVs, even in the absence of myeloid malignancies. In this report, we present the case of a 40-year-old man with Emberger syndrome (GATA2 mutation, recently diagnosed acute myeloid leukaemia [AML] and history of lymphedema with hearing loss) who developed Mucorales sinusitis while receiving his first course of remission induction chemotherapy. Additionally, we review the literature on all published cases of proven IFIs in patients with GATA2 PVs. Clinicians should be aware that patients with GATA2 PVs could be vulnerable to opportunistic IFIs, even in the absence of AML and antineoplastic therapy. Furthermore, the distinctly unusual occurrence of mucormycosis during the first course of induction chemotherapy for AML in our patient indicates that patients with germline GATA2 PVs receiving induction chemotherapy for AML might be at high risk for early onset of IFIs due to aggressive, opportunistic moulds.
We report three cases of Clostridium butyricum bacteremia associated with taking C. butyricum-related probiotics. We performed a literature review and found 11 cases of C. butyricum bacteremia including our cases. Nine cases related to probiotics. We should consider that probiotics may infect clinically unstable patients.