Unusual Pathogens Research Articles

“Mucosal infection with tsukamurella species following nasal septum procedure: a rare case report”

Introduction and Importance: Tsukamurella species are rare, aerobic, Gram-positive bacteria known to cause infections, primarily in immunocompromised individuals. This case report presents a rare instance of a mucosal infection caused by Tsukamurella species following a nasal septum procedure in an immunocompetent patient. Case Presentation: A 51-year-old man with a history of multiple hereditary exostosis, allergic rhinitis, and recent nasal fracture repair presented with persistent fevers and low back pain. Postoperatively, he developed sinus pain and small oral lesions, initially treated with antibiotics for presumed sinusitis. Despite treatment, his fever persisted, leading to an emergency department visit. Laboratory tests indicated sepsis, but a CT scan of the sinuses showed no sinusitis. Despite broad-spectrum antibiotics, the patient’s fever continued. On admission day 9, nasal endoscopy and culture identified Tsukamurella species. The patient was treated with Augmentin, fluconazole, and levofloxacin, leading to resolution of symptoms and discharge with ongoing treatment. Clinical Discussion: Tsukamurella species are uncommon pathogens that are often associated with bacteremia in immunocompromised individuals. This case highlights the diagnostic challenges and importance of considering unusual pathogens in post-procedural infections, even in immunocompetent patients. Accurate identification and appropriate management are critical in improving outcomes for patients with Tsukamurella infections. Conclusion: This case underscores the need for vigilance in diagnosing rare infections like Tsukamurella, even in immunocompetent individuals. The successful resolution with combination therapy highlights the importance of appropriate antibiotic selection in managing such infections.

Unusual presentations of chronic osteomyelitis caused by unusual pathogens: A case series from a tertiary care hospital of eastern India

Unusual presentations of chronic osteomyelitis caused by unusual pathogens: A case series from a tertiary care hospital of eastern India

Prevalence of Co-infection of Culture-Proven Bacterial Pathogens in Microbiologically Confirmed Pulmonary Tuberculosis Patients From a Tertiary Care Center.

Tuberculosis (TB) is a chronic condition that weakens the immune system, causes structural changes in the lungs, and can lead to infections by other bacterial pathogens. Very few studies have been done to understand the magnitude of co-infection with other bacterial pathogens, so this study was conducted to understand the co-infection pattern and burden. A total of 174 microbiologically confirmed pulmonary TB patients' samples, identified by cartridge-based nucleic acid amplification test, were further tested for other bacterial pathogens by culture over a period of five months from May 2023 to September 2023. The isolates' identification and drug susceptibility were performed using the VITEK 2 system (bioMérieux, Marcy-l'Étoile, France). Of the 174 pulmonary samples tested, 19 samples grew a significant amount of other bacterial pathogens, making the prevalence 10.91% (19/174). Among the pulmonary samples tested, 54.59% were sputum, 38.5% were bronchoalveolar lavage, and 6.89% were endotracheal aspirate. Additionally, 70.11% of the patients tested were in the age group of 19-60 years. Of the patients who had co-infection, 94.73% (18/19) were male. The most common bacterial infection was caused by Pseudomonas aeruginosa, which was identified in 36.84% of the co-infection cases (7/19). This was followed by Acinetobacter baumannii in 31.57% (6/19), Klebsiella pneumoniae in 26.31% (5/19), and Stenotrophomonas maltophilia in 5.28% (1/19). Acinetobacter baumannii and Klebsiella pneumoniae showed high drug resistance, ranging from 60% to 100% against various groups of drugs tested. None of the patient samples with co-infection showed rifampicin resistance. Among all the samples with co-infection, the majority (42.10%, or 8/19) had a high load of Mycobacterium tuberculosis complex detected by CBNAAT Ultra (Cepheid, Sunnyvale, California). Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae are unusual pathogens causing infection in community patients and are known to cause illness in hospitalized patients. These organisms' resistance was also similar to the resistance shown by hospital-acquired infections. Thisindicates that bacterial co-infection in pulmonary TB patients will be similar to the pattern of hospital-acquired infections. The high prevalence of bacterial co-infections (10.91%) in patients with pulmonary TB poses a significant challenge as these bacterial pathogens are not susceptible to anti-tubercular drugs. Therefore, comprehensive screening for other bacterial infections in all pulmonary TB patients is crucial for effective treatment and outcomes.

Prevalence, risk factors, and hematologic changes in dogs from Baja California with presence of Ehrlichia spp., and coinfection with Anaplasma spp.

Ehrlichia and Anaplasma are obligate intracellular, gram-negative bacteria with tropism for hematopoietic cells, especially leukocytes and platelets. There are several Ehrlichia species that infect dogs. Ehrlichia canis is transmitted by Rhipicephalus sanguineus and replicates within monocytes and macrophages, leading to canine monocytic ehrlichiosis, a disease of worldwide distribution. The clinical signs are varied and non-specific. Anaplasma has two species that infect dogs, Anaplasma phagocytophilum and Anaplasma platys, the second also transmitted by Rhipicephalus sanguineus. This study aimed to evaluate the epidemiology and hematologic changes associated with the presence of Ehrlichia spp. and Anaplasma spp. coinfection in dogs from Baja California. Complete hematological analysis, examination of buffy coat smears, and ELISA tests were performed on blood samples from three veterinary diagnostic laboratories from Mexicali and Tijuana cities in Baja California, Mexico. A total of 5,469 dog samples were analyzed. The overall prevalence of Ehrlichia spp., was 4.79%, with a distribution of 6.3% in Mexicali (OR: 2.39 CI: 1.69-3.17) and 2.5% in Tijuana. The peak of infection was found in September. Contact with other dogs and tick infestation were the risk factors associated with infection (P < 0.05). There was 96% co-infection only in Tijuana and 0% in Mexicali. Anemia, thrombocytopenia, and hyperproteinemia are associated with Ehrlichia spp., and Ehrlichia/Anaplasma infection. In view of the foregoing, we have to maintain epidemiologic vigilance, as well as look further into the ticks present in the state and the possibility of transmission of unusual pathogens.

Aspergillus oryzae Isolated from Lung Tissue Sample in a Chronic Respiratory Illness Patient from South India

Opportunistic fungal infection by Aspergillus oryzae in patients with chronic respiratory condition is rare in India. A 52-year-old male with a history of diabetes mellitus, chronic smoking, and alcoholism presented with chronic cough, breathlessness, and recurrent blood in sputum. CT imaging revealed features consistent with old pulmonary tuberculosis sequelae and the presence of a right lung lower lobe aspergilloma. The patient underwent a right lower lobectomy, and histopathological examination confirmed severe acute and chronic bronchiolitis with bronchiectasis and organizing pneumonia, indicative of fungal ball formation. Microbiological analysis identified Aspergillus species, possibly A. flavus complex, with sequencing confirming A. oryzae. This case is unique as A. oryzae is typically associated with food fermentation and rarely implicated in invasive lung infections, especially outside regions of traditional exposure, like Japan. The rarity of this presentation underscores the importance of considering unusual pathogens in clinical practice and utilizing advanced diagnostic techniques such as sequencing for accurate identification. The successful outcome of this case, with prolonged antifungal therapy based on microbiological confirmation and clinical follow-up, suggests the importance of personalized treatment strategies. This case report adds to the growing body of evidence on the clinical significance and pathogenic potential of A. oryzae. It underscores the importance of continued vigilance and research in fungal infections.

The Role of OCT in Follow-Up of Fungal Keratitis Caused by Beauveria bassiana in Contact Lens Wearer.

A 25-year-old Caucasic female was referred to our clinic after suffering from infectious keratitis in the right eye for a month. The patient was a contact lens user and had no history of ocular trauma. Furthermore, the patient did not report any relevant antecedent. The main complaint was intense photophobia and pain. Infectious keratitis remains one of the main complications of contact lens wear and can become a therapeutic challenge in some patients. Although the most frequent causal agent is bacterial, other causes such as herpes virus, Acanthamoeba or fungi should be considered when antimicrobial therapy does not work as expected clinically. Fungal keratitis normally appears on previously damaged corneas, but it can also develop in contact lens wearers. Beauveria bassiana is an unusual pathogen which has been diagnosed more frequently lately per the clinical reports in the last 30 years, so it can be included in the diagnostic scheme when a fungal keratitis is suspected. In clinical management, AS-OCT may be a functional tool to assess the evolution and monitor the response to microbial agents and surgery. Although more studies are needed, some characteristic features have been described and can help to diagnose a fungal keratitis against other infections. AS-OCT can also play an important role in monitoring the corneal scarring after the keratitis episode, and it may be useful to plan post-infection therapy for visual rehabilitation.

Resilience and challenges of peritoneal dialysis survivors in the aftermath of the 2023 Kahramanmaraş earthquake.

Peritoneal dialysis (PD) remains understudied in disaster nephrology. This retrospective multicenter study explores the experiences of PD survivors following the February 6, 2023, Kahramanmaraş Earthquake. Adult PD patients from 11 affected cities were analyzed to assess challenges faced during and postearthquake, alongside clinical outcomes. Among 101 participants (median age: 45 years, median PD duration: 24 months), 57 were female, with 79 on continuous ambulatory PD. Challenges included power outages and water shortages, with primary shelter in kin's houses (33%) and homes (28%). Twelve patients experienced PD program delays, and three lacked assistance postdisaster. Sixteen patients changed PD modalities, with seven experiencing postearthquake peritonitis. Clinical parameters remained stable, except for a slight decrease in hemoglobin levels. Despite challenges, PD survivors exhibited resilience, highlighting the importance of addressing peritonitis and unusual pathogens in disaster preparedness initiatives.

Streptococcus sinensis Causing Tricuspid Endocarditis in a Child: An Unusual Pathogen at an Unusual Site: A Case Report with Review of Literature

Background: Infective endocarditis (IE) involving tricuspid valve is rarely reported in children. Common etiological organisms of IE include Staphylococci, viridans group Streptococci, and Enterococci. Other less frequent organisms include Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella (HACEK) group, and Candida, accounting for 1% of cases. We describe the rare case scenario of tricuspid valve endocarditis caused by an unusual pathogen. Clinical Description: An 8-year-old girl presented with complaints of cough, shortness of breath, and intermittent fever for the past 2 months. Since 10 days before presentation, the fever had become high grade, continuous, and associated with chills and rigors. As per parents, the child had incidentally been detected with some congenital heart disease (CHD) at 3 months of age, documents being unavailable, child remaining asymptomatic till this presentation, without any medications. On examination, the child was malnourished with pallor, Grade 3 clubbing, tachypnea, and tachycardia. Auscultation revealed bilateral basal crepitations and a pansystolic murmur of Grade 4 in tricuspid area. Management and Outcome: Along with routine investigations, a two-dimensional echocardiography was done which revealed perimembranous ventricular septal defect with left-to-right shunt, tricuspid valve vegetations with anterior tricuspid leaflet prolapse with ruptured chordea, severe tricuspid regurgitation, and thickened aortic valve with good biventricular function. Blood culture showed growth of Streptococcus sinensis. The child was treated with oxygen, diuretics, and intravenous ciprofloxacin and gentamicin according to antibiotic sensitivity pattern. The child became hemodynamically stable and symptomatically improved after 3 weeks of treatment. Conclusion: This case creates awareness regarding an usual pathogen – S. sinensis as an etiological agent of IE, involving an unusual site – the tricuspid valve, in a child with CHD.

Infective Endocarditis due to Unusual Pathogens Complicated with Pulmonary Thromboembolism: A Rare Occurrence in a Premature Infant

Background: Survival of low birth weight preterm neonates has increased with the availability of better neonatal care, however, the use of central lines for longer duration increases the risk of bacterial and fungal sepsis. Neonatal infective endocarditis (IE) is a rare presentation of neonatal sepsis and is often associated with complications and high mortality. Clinical Description: A 36 weeker, premature baby, hospitalized for early onset sepsis, was transferred to our hospital on day 15 of life, with an umbilical catheter in situ, with fever, respiratory distress, and persistent thrombocytopenia. Clinical examination revealed decreased oxygen saturation, crepitations in the right lung field, systolic murmur, and hepatomegaly. Management and Outcome: Baseline investigations revealed positive septic screen with thrombocytopenia with meningitis, neonatal cholestasis, and right sided consolidation on chest X ray. A two dimensional echocardiography (ECHO) revealed vegetation on the tricuspid valve, and blood culture from two sites revealed growth of Candida tropicalis and Serratia marcescens. Colistin, tigecycline, and amphotericin B therapy were initiated as per sensitivity along with low molecular weight heparin for prevention of embolization. The baby developed acute worsening in respiratory distress after 4 weeks of therapy. Repeat ECHO revealed increased size of cardiac vegetation and computed tomography of thorax with pulmonary angiography revealed pulmonary thromboembolism. Unfortunately, the baby succumbed to complications of IE. Conclusion: Invasive instrumentations such as umbilical catheterization and prolonged hospitalizations of premature newborns predispose them to develop IE, especially with unusual organisms. Such infections have a complicated course and may be fatal.

Aeromonas septicaemia - A case series

are ubiquitous Gram-negative bacilli which are seen in brackish or fresh water and soil in subtropical or temperate countries. They were considered as pathogen of many animals including fish but recently they have been gaining importance due to its ability to infect and colonise in human body. Though the most common site of infection is gastrointestinal tract, it can cause extraintestinal infections like skin and soft tissue infections, urinary tract infections, biliary tract infections and bacteremia. Its ability to acquire antibiotic resistance naturally from the environment and due to the inappropriate use of antibiotics makes treatment of this unusual pathogen difficult. Many studies have shown high morbidity and mortality rates associated with . Therefore, though it was initially considered as a rare cause of bacteremia, should be considered as an important nosocomial pathogen.

Unusual Pathogen Isolated in Patient with Ludwig's Angina

Unusual Pathogen Isolated in Patient with Ludwig's Angina

Assessment of the prognosis of the outcome of severe community-acquired pneumonia caused by <i>Klebsiella pneumoniae</i>

Introduction. The problem of an adequate assessment of the prognosis of the outcome of severe community-acquired pneumonia (CAP) is particularly difficult if it is caused by an unusual pathogen for it, in particular Klebsiella pneumoniae.The objective was to develop the approach for predicting the survival of a heterogeneous population of patients with CAP caused by Klebsiella pneumoniae using statistical approaches based on artificial neural networks.Materials and methods. The design is a retrospective, multicenter, controlled, non-randomized study. Inclusion criteria: clinical, laboratory and radiological diagnosis of CAP associated with Klebsiella pneumoniae with a SOFA score of 2 or more points. The development included 100 patients. 50 died. The prognostic significance of the SOFA, APACHE II, PSI/PORT, Glasgow and Charlson comorbidity index, procalciotonin, C-reactive protein scales was evaluated. The data obtained were evaluated in the StatPlus 7 and Pycharm GPT programs.Results. None of the stated scales has shown its significance. There were no statistically significant differences between the surviving and deceased patients in terms of the level of biomarkers studied. In this regard, we have compiled a logistic regression equation for assessing the prognosis based on a combination of the SOFA score, the Charlson index and the procalcitonin level.Conclusion. In assessing the prognosis of outcome in patients with CAP caused by Klebsiella pneumoniae, it is advisable to use a combination of data from the SOFA score, Charlson comorbidity index and procalciotonin levels. Threshold critical values are SOFA score of more than 4 points, Charlson comorbidity index of more than 7 points, procalciotonin level of more than 2 ng/ml.

Coronavirus disease 2019 (COVID-19)-associated brain abscesses caused by Pseudomonas aeruginosa and Aspergillus fumigatus: two case and a review of the literature

BackgroundBacterial and fungal superinfections are commonly reported in patients with coronavirus disease 2019.Case presentationWe report the first case of brain and intramedullary abscesses caused by Pseudomonas aeruginosa and a rare case of brain abscesses caused by Aspergillus fumigatus in two post-coronavirus disease 2019 patients. The first patient—34-year-old Iranian woman—presented with weakness of the left upper limb, headaches, and lower limb paresthesia. She had a history of undiagnosed diabetes and had received corticosteroid therapy. The second patient—45-year-old Iranian man—presented with right-sided weakness and had a history of intensive care unit admission. Both patients passed away despite appropriate medical therapy.ConclusionThe immune dysregulation induced by coronavirus disease 2019 and its’ treatments can predispose patients, especially immunosuppressed ones, to bacterial and fungal infections with unusual and opportunistic pathogens in the central nervous system. Pseudomonas aeruginosa and Aspergillus fumigatus should be considered as potential causes of brain infection in any coronavirus disease 2019 patient presenting with neurological symptoms and evidence of brain abscess in imaging, regardless of sinonasal involvement. These patients should get started on appropriate antimicrobial therapy as soon as possible, as any delay in diagnosis or treatment can be associated with adverse outcomes.

Outbreak of Pandoraea commovens Infections among Non-Cystic Fibrosis Intensive Care Patients, Germany, 2019-2021.

Pandoraea spp. are gram-negative, nonfermenting rods mainly known to infect patients with cystic fibrosis (CF). Outbreaks have been reported from several CF centers. We report a Pandoraea spp. outbreak comprising 24 non-CF patients at a large university hospital and a neighboring heart center in Germany during July 2019-December 2021. Common features in the patients were critical illness, invasive ventilation, antimicrobial pretreatment, and preceding surgery. Complicated and relapsing clinical courses were observed in cases with intraabdominal infections but not those with lower respiratory tract infections. Genomic analysis of 15 isolates identified Pandoraea commovens as the genetically most similar species and confirmed the clonality of the outbreak strain, designated P. commovens strain LB-19-202-79. The strain exhibited resistance to most antimicrobial drugs except ampicillin/sulbactam, imipenem, and trimethoprim/sulfamethoxazole. Our findings suggest Pandoraea spp. can spread among non-CF patients and underscore that clinicians and microbiologists should be vigilant in detecting and assessing unusual pathogens.

Isolation of a rare pathogen <i>Chryseobacterium indologenes</i> in patients with pneumonia

Introduction. Chryseobacterium indologenes bacteria are rarely detected, poorly studied opportunistic bacteria of the nonfermenting gram-negative bacilli group that are characterized by high intrinsic and acquired multidrug resistance and involvement in healthcare associated infections.Aim. To analyze detection rate of C. indologenes strains from various biomaterials obtained from patients with pneumonia, as well as levels of pathogen drug resistance to antimicrobial drugs.Materials and methods. The research included 1740 clinical samples obtained from patients with pneumonia hospitalized in in-patient facilities of the Khabarovsk city during the COVID-19 pandemic. Clinical samples included 1305 respiratory samples (744 sputum samples and 561 nasopharyngeal swabs), 435 samples of autopsy material (lung tissue) obtained from patients with a fatal outcome of the disease. The study was performed via classical bacteriological method. Pathogens were identified with Vitek 2 bacteriological analyzer and Vitek MS mass spectrometer. Sensitivity to antimicrobial drugs was determined by disk-diffusion method and in a bacteriological analyzer.Results. A comparative analysis of detection of the entire nonfermenting gram-negative bacteria (NFGNB) group and C. indologenes from various clinical samples was carried out. Detection rate of NFGNB equaled 17.3%. NFGNB were isolated from autopsy material most often ‒ in 31.7% of cases, less often ‒ from sputum and nasopharyngeal smears (13.8% and 10.7%, respectively). C. indologenes was detected in 0.5% of the cases (8 isolates out of 1740 samples). Isolation of this pathogen was most frequent in nasopharyngeal smears – in 1.1% (6 cases out of 561 samples), least frequent ‒ from sputum, which totaled 0.3% (2 isolates from 744 samples). The detection rate of the pathogen in respiratory samples equaled 0.6% (8 isolates out of 1305 samples). This pathogen was not found in the autopsy material. Carbapenem-resistant variants of C. indologenes were isolated in 75% (6 cases out of 8) of the cases.Conclusion. Further intensifying of diagnostic methods will result in more frequent detection of these unusual pathogens, clinical significance of which needs more justification.

C2 (Clinical Case) Complicated Sinusitis in an Adolescent Swimmer in the COVID-19 Pandemic: An Unexpected Microbial Player

Abstract Introduction/Background There are increasing reports of complicated sinusitis following post-pandemic viral surges. Streptococcus anginosus and Staphylococcus aureus (SA) are common causes. However, unusual pathogens may need to be considered in the face of inadequate therapeutic response. Case Description A previously healthy 13-year-old boy presented with fever, facial pain, and headache two weeks following presumed COVID-19 infection based on exposure history and symptoms. While recovering, he had been swimming daily and recalled inhaling pool water. On examination he was febrile with a tender mid-forehead swelling and left periorbital swelling without features of orbital cellulitis. There was no meningism or focal neurological deficits. Investigations revealed leukocytosis (19.1 x109/L), elevated CRP (156.8 mg/L) and sterile blood cultures. Head imaging confirmed sinusitis complicated by Pott’s puffy tumor, a small subdural empyema and sinus venous thrombosis. Ceftriaxone, metronidazole, and vancomycin were initiated with de-escalation of the latter to cloxacillin after sinus cultures grew methicillin-sensitive SA. Despite broadening to meropenem and vancomycin, he progressed to develop cerebritis. Legionella species identified from intracranial sampling using 16s RNA, allowed targeted therapy with levofloxacin and successful resolution after six weeks of therapy. Discussion The development of this patient’s Pott’s puffy tumor and intracranial complications seemed consistent with post-viral sinusitis in terms of onset and growth of SA. However, his inadequate response to broad-spectrum therapy and sterile cultures from intracranial sampling prompted request for 16sRNA testing. Subsequent disclosure of freshwater swimming exposure with aspiration event raised concerns for water-borne pathogens such as Legionella. The aspiration event occurring in presence of persisting congestion, resulted in Legionella species seeding already inflamed sinuses and further tracking intracranially. Without special cultures required to recover Legionella, this pathogen was initially missed, resulting in disease progression and delayed targeted therapy. Fluroquinolones or macrolides are required for treatment of this pathogen. Conclusion Given that post-viral sinusitis may be anticipated during viral surges, practitioners should consider the role of waterborne pathogens in hosts with significant swimming exposure who worsen on usual therapy. Microbiology and infectious diseases involvement is encouraged to optimize detection and management of waterborne infection. Practitioners are reminded that in the face of therapeutic failure, it is critical to revisit the history for unusual exposures, determine immunocompetence, and explore potential bug-drug mismatch.

Spinal Epidural Abscess and Strep Pharyngitis

Spinal epidural abscesses (SEA) require prompt diagnosis to avoid devastating consequences. Here, we discuss the case of a healthy 20-year-old college student-with a recent diagnosis of strep pharyngitis-who presented with neck pain, fever, and a neurologic deficit-the most common symptoms of SEA. Magnetic resonance imaging revealed a T1-postcontrast, peripherally enhancing epidural collection from C3-T5 with associated cord compression and T3 osteomyelitis. The patient was treated with emergent skip hemilaminectomies for abscess evacuation. Surgical cultures grew Fusobacterium necrophorum, a highly unusual pathogen in SEA. It is an oral anaerobe that translocated through the mucosa in the setting of strep pharyngitis. We treated the patient with ceftriaxone for 6 weeks. The patient had a full neurologic recovery and remains without recurrence of infection 11 months postoperatively. Healthy patients without obvious risk factors may present with SEA, highlighting the need for atypical cases such as these to be brought to clinicians' attention.

Evaluation of infections in patients with kidney and liver transplantation

Objectives: Infection is a frequent complication of organ transplantation and is associated with significant morbidity and mortality. Methods: Patients who had liver and kidney transplants between 2011 and 2022, who were hospitalized in our hospital, and who were consulted for infectious diseases were retrospectively analyzed from hospital records. Results: Of the patients included in the study, 9 (28%) were female, 23 (72%) were male, and the mean age was 33.7 ± 11.3 years. Patients had congestive heart failure (87.2%, n = 28, hypertension (43.7%, n = 14), and chronic obstructive pulmonary disease (21.8%, n = 7). Twenty (62.5%) kidney transplant recipients and 12 (37.5%) liver transplant recipients were seen within ten years. The most common infections were urinary tract infection in 8 ( 25%) patients and pneumonia in 11 (34.3%). The other infections were gastrointestinal infections such as diarrhoea, bloodstream infections and COVID-19 and Cytomegalovirus. Culture-isolated organisms in 20 (62.5%) of the 32 patients admitted with infections. The microbiological data were notable for some unusual and opportunistic pathogens, including one case of acute cytomegalovirus viremia. Severe sepsis had been seen in six (18.75%) out of 32 patients with documented infections. Conclusions: Infection prevention has become a cornerstone of modern transplantation medicine due to the significant incidence of post-transplant infectious complications resulting from improved immunosuppressive therapies and surgical procedures.

Neonatal Paenibacilliosis: Paenibacillus Infection as a Novel Cause of Sepsis in Term Neonates With High Risk of Sequelae in Uganda.

Paenibacillus thiaminolyticus may be an underdiagnosed cause of neonatal sepsis. We prospectively enrolled a cohort of 800 full-term neonates presenting with a clinical diagnosis of sepsis at 2 Ugandan hospitals. Quantitative polymerase chain reaction specific to P. thiaminolyticus and to the Paenibacillus genus were performed on the blood and cerebrospinal fluid (CSF) of 631 neonates who had both specimen types available. Neonates with Paenibacillus genus or species detected in either specimen type were considered to potentially have paenibacilliosis, (37/631, 6%). We described antenatal, perinatal, and neonatal characteristics, presenting signs, and 12-month developmental outcomes for neonates with paenibacilliosis versus clinical sepsis due to other causes. Median age at presentation was 3 days (interquartile range 1, 7). Fever (92%), irritability (84%), and clinical signs of seizures (51%) were common. Eleven (30%) had an adverse outcome: 5 (14%) neonates died during the first year of life; 5 of 32 (16%) survivors developed postinfectious hydrocephalus (PIH) and 1 (3%) additional survivor had neurodevelopmental impairment without hydrocephalus. Paenibacillus species was identified in 6% of neonates with signs of sepsis who presented to 2 Ugandan referral hospitals; 70% were P. thiaminolyticus. Improved diagnostics for neonatal sepsis are urgently needed. Optimal antibiotic treatment for this infection is unknown but ampicillin and vancomycin will be ineffective in many cases. These results highlight the need to consider local pathogen prevalence and the possibility of unusual pathogens when determining antibiotic choice for neonatal sepsis.

The Genetic Requirements for HiVir-Mediated Onion Necrosis by Pantoea ananatis, a Necrotrophic Plant Pathogen.

Pantoea ananatis is an unusual bacterial pathogen that lacks typical virulence determinants yet causes extensive necrosis in onion foliage and bulb tissues. The onion necrosis phenotype is dependent on the expression of the phosphonate toxin, pantaphos, which is synthesized by putative enzymes encoded by the HiVir (high virulence) gene cluster. The genetic contributions of individual hvr genes in HiVir-mediated onion necrosis remain largely unknown, except for the first gene, hvrA (phosphoenolpyruvate mutase, pepM), whose deletion resulted in the loss of onion pathogenicity. In this study, using gene-deletion mutation and complementation, we report that, of the ten remaining genes, hvrB to hvrF are also strictly required for the HiVir-mediated onion necrosis and in-planta bacterial growth, whereas hvrG to hvrJ partially contributed to these phenotypes. As the HiVir gene cluster is a common genetic feature shared among the onion-pathogenic P. ananatis strains that could serve as a useful diagnostic marker of onion pathogenicity, we sought to understand the genetic basis of HiVir-positive yet phenotypically deviant (non-pathogenic) strains. We identified and genetically characterized inactivating single nucleotide polymorphisms in the essential hvr genes of six phenotypically deviant P. ananatis strains. Finally, inoculation of cell-free spent medium of the isopropylthio-β-galactoside (IPTG)-inducible promoter (Ptac)-driven HiVir strain caused P.ananatis-characteristic red onion scale necrosis as well as cell death symptoms in tobacco. Co-inoculation of the spent medium with essential hvr mutant strains restored in-planta populations of the strains to the wild-type level, suggesting that necrotic tissues are important for the proliferation of P. ananatis in onion. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.