Invasive mold infections: virulence and pathogenesis of mucorales

COVID-19-Associated Rhino-Orbital Mucormycosis: Histological and Electron Microscopy Characteristics

COVID-19-associated rhino-orbital mucormycosis has become a new clinical entity. This study's aim was to evaluate the histopathological and ultramicroscopic morphological aspects of this fungal infection. This was an observational retrospective study on eight patients from three tertiary centers in Romania. The tissue samples collected during functional endoscopic sinus surgery were studied through histopathological examination, scanning electron microscopy, and transmission electron microscopy. In the histopathological examination, the morphological aspects characteristic of mucormycosis in all cases were identified: wide aseptate hyphae with right-angle ramifications, which invade blood vessels. One case presented perineural invasion into the perineural lymphatics. And in another case, mucormycosis-aspergillosis fungal coinfection was identified. Through scanning electron microscopy, long hyphae on the surface of the mucosa surrounded by cells belonging to the local immune system were identified in all samples, and bacterial biofilms were identified in half of the samples. Through transmission electron microscopy, aseptate hyphae and bacterial elements were identified in the majority of the samples. Rhino-orbital-cerebral mucormycosis associated with COVID-19 produces nasal sinus dysbiosis, which favors the appearance of bacterial biofilms. The way in which the infection develops depends on the interaction of the fungi with cells of the immune system.

Perceptions, knowledge, and communication preferences about indoor mold and its health implications among persons affected by Hurricane Harvey: a focus group analysis

Background

Among people affected by Hurricane Harvey, we assessed experiences and perceptions (e.g., knowledge, attitudes, and practices) regarding mold and its impact on health and elicited participants’ opinions about how to improve public health messaging about indoor mold after a large flooding event.

Methods

Houston Health Department conducted four focus groups with 31 Houston metropolitan area residents during January to March 2020, using a semi-structured discussion guide and federal communication materials about indoor mold. Drawing from a theoretical framework analysis, transcripts were grouped into relevant themes using inductive and deductive coding.

Results

Hurricane Harvey had a large impact on participants’ living standards, and widespread financial barriers to remediation led to long-term mold exposure for many participants. Knowledge about mold’s impact on health and proper mold clean-up practices varied, and clean-up behaviors did not commonly align with federal guidance. Participants generally preferred traditional forms of outreach, such as in-person, radio, and television announcements, to communicate public health messaging.

Conclusions

More strategic dissemination of expanded public health educational materials about proper mold clean-up practices and the health risks of mold exposure following flooding events is needed.

Histopathological Study of Mucormycosis in Post COVID-19 Patients and Factors Affecting it in a Tertiary Care Hospital

Introduction. COVID-19 is an infection caused by severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) which may be associated with a wide range of bacterial and fungal co-infections. Mucormycosis is an opportunistic fungal infection occurring in post COVID-19 patients. Objectives. To study the role of histopathology in mucormycosis and the predisposing factors associated in development of mucormycosis in post COVID-19 patients. Materials and methods. A prospective observational study was conducted in our hospital in the pathology department over a period of 3 months on 200 patients with mucormycosis who were infected with SARS-CoV-2 virus. Results. Out of the 200 patients with mucormycosis studied in post COVID-19 patients, age ranged from 21-80 years, of which 132 were men and 68 were women. Sites involved by mucormycosis were sinuses, orbit, cranium, and cutaneous. Ethmoid sinus was most involved, followed by maxillary sinus. Diabetes was present in 162 patients and hypertension in 92 patients. On histopathological examination, fungal load was severe in 49 patients, angioinvasion was present in 48 patients, perineural invasion was present in 32 patients, and necrosis was present in 121 patients. The number of patients discharged after surgery was 169, whereas 31 died. Conclusion. Histopathological features of mucormycosis like angioinvasion, perineural invasion, severe fungal load, and large areas of necrosis were directly proportional to the mortality rate. Thus, histopathologists can help in assessing prognosis at the time of tissue diagnosis, so that clinicians can optimize treatment accordingly. Diabetes and history of corticosteroid intake for treatment of COVID-19 were the two commonest predisposing factors for development of mucormycosis.

Mucormycosis and COVID-19-Associated Mucormycosis: Insights of a Deadly but Neglected Mycosis

The ongoing COVID-19 pandemic has quickly become a health threat worldwide, with high mortality and morbidity among patients with comorbidities. This viral infection promotes the perfect setting in patients for the development of opportunistic infections, such as those caused by fungi. Mucormycosis, a rare but deadly fungal infection, has recently increased its incidence, especially in endemic areas, since the onset of the pandemic. COVID-19-associated mucormycosis is an important complication of the pandemic because it is a mycosis hard to diagnose and treat, causing concern among COVID-19-infected patients and even in the already recovered population. The risk factors for the development of mucormycosis in these patients are related to the damage caused by the SARS-CoV-2 itself, the patient’s overstimulated immune response, and the therapy used to treat COVID-19, causing alterations such as hyperglycemia, acidosis, endothelial and lung damage, and immunosuppression. In this review, the molecular aspects of mucormycosis and the main risk factors for the development of COVID-19-associated mucormycosis are explained to understand this virus–fungi–host interaction and highlight the importance of this neglected mycosis.

Coronavirus disease: Dental review

COVID-19 was declared a pandemic outbreak by the World Health Organization, creating a significant impact on health care system. Realizing the high risk associated with this disease and its high rate of transmission, dentists were instructed by health authorities, to stop providing treatment which includes aerosols and droplets and only except emergency complaints. This was mainly for protection of dental healthcare personnel, their families, contacts, and their patients from the transmission of virus. Hence, this review focuses on the life cycle of COVID-19, its clinical symptoms and several issues concerned directly to dental practice in terms of prevention, treatment, and orofacial clinical manifestations.

COVID-19 associated mucormycosis: evolving technologies for early and rapid diagnosis

The post-coronavirus disease (COVID-19) mucormycosis is a deadly addition to the pandemic spectrum. Although it’s a rare, aggressive, and opportunistic disease, the associated morbidity and mortality are significant. The complex interplay of factors aggravating CAM is uncontrolled diabetes, irrational and excessive use of antibiotics, steroids, and an impaired immune system. Recently, India has been witnessing a rapid surge in the cases of coronavirus disease-associated mucormycosis (CAM), since the second wave of COVID-19. The devastating and lethal implications of CAM had now become a matter of global attention. A delayed diagnosis is often associated with a poor prognosis. Therefore, the rapid and early diagnosis of infection would be life-saving. Prevention and effective management of mucormycosis depend upon its early and accurate diagnosis followed by a multimodal therapeutic approach. The current review summarizes an array of detection methods and highlights certain evolving technologies for early and rapid diagnosis of CAM. Furthermore, several potential management strategies have also been discussed, which would aid in tackling the neglected yet fatal crisis of mucormycosis associated with COVID-19.

Spectrum of MR imaging findings of sinonasal mucormycosis in post COVID-19 patients

During rapid spread of coronavirus disease (COVID-19) globally, ever since WHO declared COVID-19 as pandemic, there have been various patterns of disease in terms of diagnosis, management and complications. Secondary infections are reportedly common in hospitalized and severely ill COVID-19 patients among which fungal being 10 times more common. Mucormycosis is amongst the most lethal form of Zygormycosis occurring in post COVID-19 patients. A varied patterns of disease involvement and spectrum of imaging features are observed in patients with mucormycosis in post COVID-19 patients. MRI has better efficacy than CT in detecting early invasion of mucormycosis. The goal of this review is to familiarize radiologists about the MR imaging spectrum of mucormycosis in post COVID-19 patients with potential diagnostic pitfalls in CT.

Croton cajucara Essential Oil Nanoemulsion and Its Antifungal Activities

The purpose of this study was to develop a stable nanoemulsion (NE) containing Croton cajucara 7-hydroxycalamenene-rich essential oil (NECC) with antifungal activity. The NECCs were prepared using an ultrasonic processor with Pluronic® F-127 as the aqueous phase. In order to evaluate the NECCs, the droplet size, polydispersity index (PdI), percentage of emulsification, and pH were determined along with a stability study. The NECC selected for the study had 15% surfactant, showed 100% emulsification, Pdl of 0.249, neutral pH, droplet diameters of about 40 nm, and remained stable over 150 days at room temperature. In addition, the NECC activity against some species of Zygomycetes and Candida, as well as the potential to inhibit fungal extracellular proteases, were assessed, and, finally, the hemolytic activity was evaluated. The best NECC antifungal activities were against Mucorramosissimus (Minimal inhibitory concentration (MIC) = 12.2 μg/mL) and Candida albicans (MIC = 25.6 μg/mL). The highest extracellular protease activities of M. ramosissimus and C. albicans were detected at pH 3 and 4, respectively, which were totally inhibited after NECC treatment. The NECC showed no hemolytic effect at the highest concentration tested (2 mg/mL).

Post-COVID fungal infections of maxillofacial region: a systematic review

With the advent of coronavirus disease (COVID-19) pandemic, a wide range of life-threatening maxillofacial fungal coinfections have also been observed in patients. We conducted this systematic review to collate and evaluate the data to enable clinicians to understand the disease pattern and types of mycosis and provide meticulous management of these infections in COVID-19 patients. The review was carried out in accordance with Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. A systematic electronic literature search was conducted on major databases using keywords in combination with Boolean Operators. Manuscripts discussing cases of maxillofacial fungal infections in COVID-19 patients were included. A total of 11 studies were systematically reviewed to assess the fungal coinfections in COVID-19 patients. Twenty-one cases of mucormycosis, 58 of candidiasis, and 1 each of aspergillosis and mixed infection were observed in the region of head and neck. Significant increase in invasive fungal infection is evident in patients suffering from COVID-19 which could be due to immunosuppression and other pre-existing comorbidities. Early diagnosis and intervention like systemic antifungals or surgical debridement is mandatory to reduce morbidity and mortality.

A systematic review on SARS-CoV-2-associated fungal coinfections

A severe pandemic of Coronavirus Disease (COVID‐19) has been sweeping the globe since 2019, and this time, it did not stop, with frequent mutations transforming into virulent strains, for instance, B.1.1.7, B.1.351, and B.1.427. In recent months, a fungal infection, mucormycosis has emerged with more fatal responses and significantly increased mortality rate. To measure the severity and potential alternative approaches against black fungus coinfection in COVID‐19 patients, PubMed, Google Scholar, World Health Organization (WHO) newsletters, and other online resources, based on the cases reported and retrospective observational analysis were searched from the years 2015–2021. The studies reporting mucormycosis with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2) coinfection and/or demonstrating potential risk factors, such as a history of diabetes mellitus or suppressed immune system were included, and reports published in non‐English language were excluded. More than 20 case reports and observational studies on black fungus coinfection in COVID‐19 patients were eligible for inclusion. The results indicated that diabetes mellitus, hyperglycemic, and immunocompromised COVID‐19 patients with mucormycosis were at a higher risk. We found that it was prudent to assess the potential risk factors and severity of invasive mycosis via standardized diagnostic and clinical settings. Large‐scale studies need to be conducted to identify early biomarkers and optimization of diagnostic methods has to be established per population and geographical variation. This will not only help clinicians around the world to detect the coinfection in time but also will prepare them for future outbreaks of other potential pandemics.

Observational studies and case reports of Post‐COVID black fungus co‐infection highlighted in review.

Along with risk factors, radiological interventions of black fungus co‐infection in COVID‐19 patients and challenges for accurate diagnosis were elaborated.

The review discusses interconnection between fungus and SARS‐CoV‐2 co‐infection of mechanism to identify potential biomarkers.

Our conclusion will contribute to motivate researchers to design follow‐up plans for black fungus infection in COVID‐19.

Imaging of COVID-19-associated craniofacial mucormycosis: a black and white review of the "black fungus"

A subset of diabetic COVID-19 patients treated with steroids, oxygen, and/or prolonged intensive care admission develop rhino-orbito-cerebral mucormycosis. Radiologists must have a high index of suspicion for early diagnosis, which prompts immediate institution of antifungal therapy that limits morbidity and mortality. Assessment of disease extent by imaging is crucial for planning surgical debridement. Complete debridement of necrotic tissue improves survival. Imaging features reflect the angioinvasive behaviour of fungal hyphae from the Mucoraceae family, which cause necrotising vasculitis and thrombosis resulting in extensive tissue infarction. Contrast-enhanced magnetic resonance imaging (MRI) is the imaging technique of choice. The classic “black turbinate” on contrast-enhanced imaging represents localised invasive fungal rhinosinusitis (IFRS). A striking radiological feature of disseminated craniofacial disease is non-enhancing devitalised and necrotic soft tissue at the orbits and central skull base. Sinonasal and extrasinonasal non-enhancing lesions in IFRS are secondary to coagulative necrosis induced by fungal elements. Multicompartmental and extrasinonasal tissue infarction is possible without overt bone involvement and caused by the propensity of fungal elements to disseminate from the nasal cavity via perineural and perivascular routes. Fungal vasculitis can result in internal carotid artery occlusion and cerebral infarction. Remnant non-enhancing lesions after surgical debridement portend a poor prognosis. Assessment for the non-enhancing MRI lesion is crucial, as it is a sole independent prognostic factor for IFRS-specific mortality. In this review, we describe common and uncommon imaging presentations of biopsy-proven rhino-orbito-cerebral mucormycosis in a cohort of nearly 40 COVID-19 patients.

Critical peritonitis secondary to gastrointestinal mucormycosis in a peritoneal dialysis patient: a case report

Immunodeficient patients are susceptible to systemic fungal infections; however, these rarely cause secondary peritonitis. A 66-year-old man with multiple myeloma and diabetes mellitus on continuous ambulatory peritoneal dialysis (CAPD) presented with cloudy ascitic fluid. He had been treated with corticosteroids for 1 month for Tolosa-Hunt syndrome. We diagnosed peritoneal dialysis-related peritonitis caused by Enterococcus avium, removed the CAPD catheter, and initiated intravenous ampicillin. Computed tomography (CT) revealed an intramural gastric mass and a thinning ascending colon wall. Four days later, follow-up contrast-enhanced CT showed penetration of the ascending colon and rupture of the ileocolic artery. Emergency open surgery revealed hemorrhagic infarction with mucormycosis. We initiated intravenous liposomal amphotericin B 20 days after admission; however, he died 55 days later. Anatomical abnormalities, such as gastrointestinal perforation, should be considered for peritonitis in immunodeficient patients. Gastrointestinal mucormycosis is rare but fatal, resulting from a delay in diagnosis and consequent gastrointestinal perforation. For an early diagnosis and a favorable clinical outcome, it is important to consider the risk factors for mucormycosis, including corticosteroid use, diabetes, end-stage kidney diseases.

Patient notification about suspected hospital-associated outbreaks of invasive mold infections: Considerations for public health and hospital personnel

A common type of fungal disease investigation involves hospital-associated clusters of invasive mold infections (IMIs), which typically occur among immunocompromised patients. Responding to IMI clusters can be challenging for public health and hospital personnel for several reasons such as difficulty of confirming the existence of an outbreak, difficulty of determining source. Although many resources exist to guide patient notification about healthcare incidents (eg, bloodborne exposures, disease outbreaks), IMI clusters involve special considerations related to the complex diseases, uncertain exposures, and differential benefits and risks of notification. Early, nuanced communication about hospital-associated IMI clusters is almost always the best course of action to help reduce risks to patients' health and foster trust between patients and hospitals.

Fungal Infections of Oral Cavity: Diagnosis, Management, and Association with COVID-19

The frequency of fungal infections is increasing due to immunodeficiency viruses and immunosuppressive drugs. The most common fungal infection of the oral cavity is candidiasis. The existence of Candida can be a part of normal commensal; hence, the isolation of Candida in the absence of clinical symptoms should exclude candidiasis. The pathogenicity of Candida is witnessed as opportunistic when immune status is compromised. Oral fungal infections are uncommon, but when identified, these infections are associated with greater discomfort and are sometimes destruction of tissues. Cytology and tissue biopsy are helpful in confirming the clinical diagnosis. The management of oral fungal infections must strategically focus on signs, symptoms, and culture reports. This article reviews information on diagnosis and therapeutic management of aspergillosis, cryptococcosis, histoplasmosis, blastomycosis, mucormycosis, and geotrichosis.

Fungal-Bacterial Interactions in Health and Disease

Fungi and bacteria encounter each other in various niches of the human body. There, they interact directly with one another or indirectly via the host response. In both cases, interactions can affect host health and disease. In the present review, we summarized current knowledge on fungal-bacterial interactions during their commensal and pathogenic lifestyle. We focus on distinct mucosal niches: the oral cavity, lung, gut, and vagina. In addition, we describe interactions during bloodstream and wound infections and the possible consequences for the human host.

Passage of fiproles and imidacloprid from urban pest control uses through wastewater treatment plants in northern California, USA

Urban pest control insecticides-specifically fipronil and its 4 major degradates (fipronil sulfone, sulfide, desulfinyl, and amide), as well as imidacloprid-were monitored during drought conditions in 8 San Francisco Bay (San Francisco, CA, USA) wastewater treatment plants (WWTPs). In influent and effluent, ubiquitous detections were obtained in units of ng/L for fipronil (13-88 ng/L), fipronil sulfone (1-28 ng/L), fipronil sulfide (1-5 ng/L), and imidacloprid (58-306 ng/L). Partitioning was also investigated; in influent, 100% of imidacloprid and 62 ± 9% of total fiproles (fipronil and degradates) were present in the dissolved state, with the balance being bound to filter-removable particulates. Targeted insecticides persisted during wastewater treatment, regardless of treatment technology utilized (imidacloprid: 93 ± 17%; total fiproles: 65 ± 11% remaining), with partitioning into sludge (3.7-151.1 μg/kg dry wt as fipronil) accounting for minor losses of total fiproles entering WWTPs. The load of total fiproles was fairly consistent across the facilities but fiprole speciation varied. This first regional study on fiprole and imidacloprid occurrences in raw and treated California sewage revealed ubiquity and marked persistence to conventional treatment of both phenylpyrazole and neonicotinoid compounds. Flea and tick control agents for pets are identified as potential sources of pesticides in sewage meriting further investigation and inclusion in chemical-specific risk assessments. Environ Toxicol Chem 2017;36:1473-1482. © 2016 SETAC.

Primary Gangrenous Cutaneous Mold Infections in a Patient With Cancer and Neutropenia

BACKGROUND

Opportunistic fungal infections caused by Aspergillus and Candida followed by infections with Fusarium, Rhizopus, Mucor, and Alternaria species are an important cause of morbidity and mortality in patients with hematological malignancies. Cutaneous mucormycosis infections are rare, and the incidence, outcomes, and factors associated with survival in the setting of hematological malignancies are not clear.

METHODS

A literature search was conducted for all cases of primary cutaneous mold infections in patients with hematological malignancy, of which 50 cases were found. Our case of a patient with a hematological malignancy who sustained a cat bite that in turn caused a primary cutaneous mold infection is also included.

RESULTS

In the 51 cases identified, 66.7% were neutropenic upon presentation, and 54.9% were male with an average age of 32 years. Aspergillus species (33.3%) was the most cited followed by Rhizopus species (19.6%). Overall mortality rate was 29.4% and was observed more frequently in patients with neutropenia (60.0%) and without surgical intervention (73.3%). Survival rate was higher (35.3%) for cases utilizing both antifungal and surgical intervention. The antifungal agent with the highest survival rate was amphotericin B and its formulations (58.8%).

CONCLUSIONS

Neutropenia within hematological malignancies demonstrate a risk for developing severe cutaneous fungal infections, of which primary cutaneous mucormycosis can carry significant mortality. Combination antifungal therapy and surgical debridement appears to be associated with higher survival outcomes and warrants further investigation.

Bilateral optic nerve infarction in rhino-cerebral mucormycosis: A rare magnetic resonance imaging finding

Mucormycosis is an emerging disease in diabetes and immunocompromised patients. Rhino-orbito-cerebral mucormycosis is one of the common forms of the disease. Mucormycosis leading to ischemic optic neuropathy is a rare complication. The role of magnetic resonance imaging (MRI) in the diagnosis of ischemic optic neuropathy is limited and uncommonly reported. We report an unusual case of mucormycosis in which MRI revealed bilateral optic nerve infarction, in addition to perineural extension of the fungus along the trigeminal nerve, another uncommon imaging finding.

Fungal and mycotoxin contamination of coffee beans in Benguet province, Philippines

Coffee remains an important agricultural product in Benguet province, Philippines, but is highly susceptible to fungal and mycotoxin contamination in various stages of growth and processing and in different local climates. In this study, pre- and post-harvest coffee bean samples from temperate and warm farming areas were assessed for their fungal and mycotoxin contaminants. One hundred eighty-five fungal isolates belonging to six genera were isolated representing 88.1% of mycotoxigenic fungi. The predominant species belonged to the genus Aspergillus, which are known producers of mycotoxins. Coffee beans from the post-harvest temperate group were found to have the highest percentage mycotoxigenic contamination of 98.4%, suggesting that the risk for fungal contamination is high after drying. Determination of the mycotoxins indicated 28.6% contamination. Ochratoxin A was found to be highest in dried whole cherries which contained 97.3 μg kg(-1), whilst sterigmatocystin was also highest in dried whole cherries at 193.7 μg kg(-1). These results indicate that there are risks of fungal and mycotoxin contamination of Benguet coffee at the post-harvest stage.

Fatal disseminated mucormycosis in an immunocompotent patient: a case report and literature review

Disseminated mucormycosis is a rare entity most frequently seen in neutropenic patients with hematologic malignancies, post transplants or in patients on deferoxamine therapy. We report a 64-year-old immunocompetent male with an acute pneumonia and a generalized jaundice who died within 24 h. In the autopsy, extensive perforations of spleen and multiple hemorrhage foci on the pancreas were two significant findings. Histopathological study of tissue sections revealed typical zygomycetes hyphae in the left lung, pancreas, spleen and brain. Involvement of pancreas in this patient was one of the rare features of mucormycosis reported occasionally in the literature. Our case implies an unusual clinical presentation of disseminated mucormycosis and highlights that disseminated mucormycosis should be regarded even in the immunocompetent patients.

[Iron and invasive fungal infection]

Iron is an essential factor for both the growth and virulence of most of microorganisms. As a part of the innate (or nutritional) immune system, mammals have developed different mechanisms to store and transport this element in order to limit free iron bioavailability. To survive in this hostile environment, pathogenic fungi have specific uptake systems for host iron sources, one of the most important of which is based on the synthesis of siderophores-soluble, low-molecular-mass, high-affinity iron chelators. The increase in free iron that results from iron-overload conditions is a well-established risk factor for invasive fungal infection (IFI) such as mucormycosis or aspergillosis. Therefore, iron chelation may be an appealing therapeutic option for these infections. Nevertheless, deferoxamine -the first approved iron chelator- paradoxically increases the incidence of IFI, as it serves as a xeno-siderophore to Mucorales. On the contrary, the new oral iron chelators (deferiprone and deferasirox) have shown to exert a deleterious effect on fungal growth both in vitro and in animal models. The present review focuses on the role of iron metabolism in the pathogenesis of IFI and summarises the preclinical data, as well as the limited clinical experience so far, in the use of new iron chelators as treatment for mucormycosis and invasive aspergillosis.

Soil eukaryotic microorganism succession as affected by continuous cropping of peanut--pathogenic and beneficial fungi were selected

Peanut is an important oil crop worldwide and shows considerable adaptability but growth and yield are negatively affected by continuous cropping. Soil micro-organisms are efficient bio-indicators of soil quality and plant health and are critical to the sustainability of soil-based ecosystem function and to successful plant growth. In this study, 18S rRNA gene clone library analyses were employed to study the succession progress of soil eukaryotic micro-organisms under continuous peanut cultivation. Eight libraries were constructed for peanut over three continuous cropping cycles and its representative growth stages. Cluster analyses indicated that soil micro-eukaryotic assemblages obtained from the same peanut cropping cycle were similar, regardless of growth period. Six eukaryotic groups were found and fungi predominated in all libraries. The fungal populations showed significant dynamic change and overall diversity increased over time under continuous peanut cropping. The abundance and/or diversity of clones affiliated with Eurotiales, Hypocreales, Glomerales, Orbiliales, Mucorales and Tremellales showed an increasing trend with continuous cropping but clones affiliated with Agaricales, Cantharellales, Pezizales and Pyxidiophorales decreased in abundance and/or diversity over time. The current data, along with data from previous studies, demonstrated that the soil microbial community was affected by continuous cropping, in particular, the pathogenic and beneficial fungi that were positively selected over time, which is commonplace in agro-ecosystems. The trend towards an increase in fungal pathogens and simplification of the beneficial fungal community could be important factors contributing to the decline in peanut growth and yield over many years of continuous cropping.