Comparative genomics reveals the evolution of antimicrobial resistance in Bacteroides nordii.

Bacteroides nordii, is an understudied member of the pathogenic B. fragilis group which comprises several multidrug-resistant (MDR) strains. Thus, it is of great interest to study the genome biology of Bacteroides nordii. However, no detailed study is available that characterized B. nordii at the genetic level and explored its role as a potential pathogen. We isolated an MDR strain viz., B. nordii PGMM4098 from the pus sample and subjected it to whole genome sequencing using Illumina technology. The draft genome was de-novo assembled and annotated, followed by comprehensive comparative genomics analyses using the publicly available genome dataset of B. nordii. The pan-genome analysis revealed the open nature of B. nordii, indicating the continuous accumulation of novel genes in non-core components leading to the emergence of new strains of this species. The thirteen antimicrobial resistance (AMR) genes identified in the genomes of all B. nordii strains were part of the non-core component of the pan-genome. Of these, four AMR genes, nimE, aadS, mef(En2), and ermB/F/G were found to be acquired via the process of horizontal gene transfer (HGT) from anaerobic Bacteroidetes. Importantly, the nimE gene conferring metronidazole resistance was found to be present only in B. nordii PGMM4098, which harbors five other AMR genes encoded in its genome. Of these, nimE (metronidazole resistance), ermB/F/G (macrolide-lincosamide-streptogramin B resistance), and cfxA2/A3 (class A ß-lactam resistance) genes were further validated using targeted polymerase chain reaction assay. Notably, these three genes were also found to be under the operation of positive selective pressure suggesting the diversification of these genes, which might lead to the emergence of new MDR strains of B. nordii in the near future. Our study reported and characterized the genome of the first MDR strain of B. nordii and revealed the AMR evolution in this species using a comprehensive comparative genomics approach.

Clinical anaerobic infections in an Indian tertiary care hospital: A two-year retrospective study.

OBJECTIVE: To study the spectrum of anaerobic infections and the frequency of clinically relevant anaerobes in various infections in a tertiary care hospital in North India. METHOD: In this two-year (2018-2019) retrospective study, a total of 22,177 samples were processed both anaerobically and aerobically. The samples included blood, pus, body fluids, necrotic tissues, abscess, peritoneal fluids, and other specimens of conditions predisposing to anaerobic infections. The recovered bacterial isolates were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). RESULT: Of the 22,177 samples processed anaerobically, 1094 showed significant anaerobic growth yielding 1464 anaerobes. Bacteroides fragilis (12.7%) and Peptoniphilus harei (12.2%) were the most predominant anaerobes, whereas Escherichia coli (32.6%) and Staphylococcus aureus (13.2%) were the most frequently recovered facultative anaerobes in polymicrobial growth. Both aerobic and anaerobic data were available for 673/1094 samples, of which 68% represented a polymicrobial etiology and 32% as monomicrobial. Of the cases where complete clinical information was available (504/1094), the majority of the anaerobes were recovered from the skin and soft tissue infections (36.3%) and intra-abdominal infections (17.1%). The clinical specimen most frequently growing anaerobes was abscess (29.1%), followed by diabetic foot ulcers (14.1%). CONCLUSION: The study documents the frequency of clinically significant anaerobic bacteria in various infections, and their associations with aerobes in polymicrobial growth. The present study may aid us in devising better therapeutic strategies against both aerobes and anaerobes in anaerobic infections, which is often empirical. Besides, the data can update clinicians with the changing patterns of anaerobic infections, which remains a neglected concern.

Antimicrobial susceptibility testing of anaerobic bacteria: In routine and research.

To date, antimicrobial susceptibility testing (AST) in anaerobes is highly disarrayed. The testing is not routinely performed in many laboratories to direct appropriate antimicrobial therapy, and literature on AST remains scarce. This review aims to present the current methods employed for the AST of anaerobic bacteria both in routine and research. Anaerobes are potential human pathogens and predominate the human microbiota. Despite their significant role in human health and disease, they are not paid enough heed. The educated experience-based treatment has often been instituted with anaerobic infections due to the challenging AST and relatively predictable patterns of antimicrobial resistance (AMR). However, the AMR in anaerobes remains no more predictable, especially in Gram-negative anaerobes like Bacteroides spp., where multi-drug resistance is also emerging. The changing antibiograms and the emergence of resistance determinants in anaerobes necessitate routine AST, periodic monitoring, and literature review of these organisms. The present scenario dictates to limit the empirical management of anaerobic infections and encourage consistent AST practice in routine by employing economical, faster, and more pragmatic approaches, especially in tertiary care setups that cater to a vast patient population and are held accountable for producing accurate clinical and surveillance data. The article may provide a broad perspective on the topic and different AST solutions.

Comparative evaluation of agar dilution and broth microdilution by commercial and in-house plates for Bacteroides fragilis group: An economical and expeditious approach for resource-limited settings.

OBJECTIVE: To compare the performance of agar dilution and broth microdilution by commercial and in-house prepared plates for the Bacteroides fragilis group. The cost analysis was performed to demonstrate that in-house prepared BMD plates were a suitable alternative to agar dilution given the high cost and low feasibility of incorporating commercial BMD plates in routine, particularly in the tertiary care institutes of many low- and middle-income countries. METHODS: Thirty B. fragilis group isolates were tested against six antibiotics, frequently used as empirical therapy for anaerobic infections including metronidazole, clindamycin, imipenem, piperacillin-tazobactam, cefoxitin, and chloramphenicol. The running consumable expenditure for all methodologies was calculated. RESULTS: The results demonstrated essential and categorical agreement of >90% for all antibiotics except cefoxitin, which showed <90% categorical agreement. No major or very major errors were observed. We observed a high agreement and strong concordance for MIC values between both methods and inter-rate reliability of >0.9 by Cohen's kappa analysis, indicating almost perfect agreement between both methods using either of the plates. In contrast to agar dilution, a 20.5 fold cost reduction was seen in BMD using in-house plates and a 5.8 fold reduction using commercial plates to test a single isolate. However, when testing 30 isolates concurrently the cost significantly increased for commercial BMD plates by 8.4 folds, and only 1.03 fold cost reduction was seen with in-house BMD plates. CONCLUSION: BMD gives comparable results to agar dilution and can be considered a method of choice to test a small number of samples. The technique is an economical option when plates are standardized in-house and could be employed for susceptibility testing of the B. fragilis group.

Complexities of Hemifacial Microsomia: A Case Study of Mandibular Hypoplasia and Ear Deformity.

Hemifacial microsomia (HFM) presents a complex congenital anomaly characterized by the asymmetric underdevelopment of facial structures, predominantly affecting the ear, mouth, and mandible on one side of the face. This case study examines the intricacies of HFM through the presentation of a 23-year-old female with congenital deformities of the left ear and mandibular hypoplasia. Clinical and radiological evaluations revealed significant facial malformations, including mandibular hypoplasia, left temporomandibular joint fusion, and maxillary abnormalities, confirming the diagnosis of HFM. Management of HFM necessitates a multidisciplinary approach involving otolaryngologists, maxillofacial surgeons, orthodontists, and audiologists to comprehensively address functional and aesthetic concerns. Early diagnosis and intervention, along with psychosocial support, are essential for optimizing outcomes and improving the quality of life for individuals with HFM.

Tumour thrombosis of the left axillary vein due to infiltrative ductal carcinoma causing superior vena cava obstruction.

Invasive ductal carcinoma is the most common type of breast cancer and can affect any age group, predominantly females older than 55 years of age. We present a case of a female in her mid-30s complaining of a fungating mass in the upper outer quadrant of the left anterior chest wall. On workup of the patient, it was histopathologically found that the patient was affected by infiltrating ductal carcinoma of the left breast, which was causing tumoral thrombosis of the left axillary vein. Also, thrombosis of the right axillary vein, bilateral brachiocephalic veins, and superior vena cava with a focal hepatic hotspot sign were appreciated on contrast-enhanced computed tomography scan. No such case of tumoral thrombosis of the axillary vein causing superior vena cava obstruction has been reported in recent literature.

Bladder Carcinoma With Solitary Skull Metastasis: A Rare Presentation in a Middle-Aged Female.

Bladder carcinoma is a common malignant tumor of the urinary system, with the leading cause of death being the metastasis of cancer. It, however, is a rare malignancy in the Indian population with the incidence being higher in males compared to females. The most common sites of metastasis for bladder carcinoma are the peritoneum, liver, lung, pleura, lymph nodes, adrenals, intestine, and kidney. Metastasis to the heart and brain are rare. Only a few cases of bladder cancer metastasizing to the skull have been reported to date. Here in this article, we describe a female patient who presented with metastasis to the calvarium from bladder cancer before the identification of the original tumor.

Role of End Plate Changes and Paraspinal Muscle Pathology in Lower Back Pain: A Narrative Review.

Degenerative changes of the lumbar intervertebral disc are the most significant causes of enduring lower back pain. The possibility of the diagnosis is limited in people with this low back pain. Therefore, it is essential to identify the relevant back pain subgroups. The paraspinal muscles, that is, the muscles that attach to the spine, are necessary for the proper functioning of the spine and the body; insufficiency can result in back pain. Lower back pain disorders are strongly associated with altered function or structure of these paraspinal muscles, especially fibrosis and fatty infiltration. Modic changes are the bone marrow changes of the end plate in the vertebral body seen on MRI. These are strongly related to degeneration of the disc and are common in individuals with back pain symptoms. Articles were selected from Google Scholar using the terms 'Modic changes,' 'end plate changes,' 'paraspinal muscles,' and 'lower back pain. ' This article compiled different studies aiming to enhance the comprehension of biochemical processes resulting in the development of lumbar pain. Search using the keywords 'Modic changes,'' end plate changes lower back pain,' 'paraspinal muscles lower back pain,' and 'Modic changes lower back pain' on Google Scholar yielded 33000, 41000, 49400, and 17,800 results, and 958, 118, 890 and 560 results on Pubmed respectively.

Radiological Features of Extramedullary Hematopoiesis in a Young Male With Beta-Thalassemia: A Case Report.

The formation of the blood elements and their maturation is called hematopoiesis. In adults, this typically takes place in the bone marrow of vertebrae, ribs, and long bones. In contrast, during fetal development, the primary sites of hematopoiesis are the spleen, liver, and the yolk sac. This process of hematopoiesis, when it occurs in sites other than the bone marrow, is called the extramedullary hematopoiesis (EMH). Extramedullary hematopoiesis usually happens in patients with blood disorders like sickle cell disease and thalassemia, where there is failure of hematopoiesis in the primary sites. Here, we present a young male with beta-thalassemia who presented with shortness of breath and palpitations for one month. This manuscript discusses the imaging findings of the EMH in our patient.

Isolated Renal Hydatid Cyst: A Rare Case.

Hydatid disease is a parasitic infection caused by a cestode from the Taeniidae family, by Echinococcus multilocularis or Echinococcus granulosus, predominantly occurring in the lungs and liver. Although the kidney can be involved in hydatid cysts, isolated kidney hydatidosis is very rare. Most cases present with non-specific complaints or remain asymptomatic for years. Hence, imaging is very useful in the diagnosis. Here, we report an isolated hydatid cyst involving the right kidney.

Anaerobic Gram-Negative Bacteria: Role as a Reservoir of Antibiotic Resistance.

BACKGROUND: Anaerobic Gram-negative bacteria (AGNB) play a significant role as both pathogens and essential members of the human microbiota. Despite their clinical importance, there remains limited understanding regarding their antimicrobial resistance (AMR) patterns. This knowledge gap poses challenges in effectively managing AGNB-associated infections, as empirical treatment approaches may not adequately address the evolving resistance landscape. To bridge this research gap, we conducted a comprehensive study aimed at exploring the role of human AGNB as a reservoir of AMR. This can provide valuable insights for the prevention and management of anaerobic infections. METHODS: We studied the prevalence of AMR and AMR determinants conferring resistance to metronidazole (nimE), imipenem (cfiA), piperacillin-tazobactam (cepA), cefoxitin (cfxA), clindamycin (ermF), chloramphenicol (cat) and mobile genetic elements (MGEs) such as cfiAIS and IS1186 associated with the cfiA and nim gene expression. These parameters were studied in Bacteroides spp., Fusobacterium spp., Prevotella spp., Veillonella spp., Sutterella spp., and other clinical AGNB. RESULTS: Resistance to metronidazole, clindamycin, imipenem, piperacillin-tazobactam, cefoxitin and chloramphenicol was 29%, 33.5%, 0.5%, 27.5%, 26.5% and 0%, respectively. The presence of resistance genes, viz., nim, ermF, cfiA, cepA, cfxA, was detected in 24%, 33.5%, 10%, 9.5%, 21.5% isolates, respectively. None of the tested isolates showed the presence of a cat gene and MGEs, viz., cfiAIS and IS1186. The highest resistance to all antimicrobial agents was exhibited by Bacteroides spp. The association between resistant phenotypes and genotypes was complete in clindamycin, as all clindamycin-resistant isolates showed the presence of ermF gene, and none of the susceptible strains harbored this gene; similarly, all isolates were chloramphenicol-susceptible and also lacked the cat gene, whereas the association was low among imipenem and piperacillin-tazobactam. Metronidazole and imipenem resistance was seen to be dependent on insertion sequences for the expression of AMR genes. A constrained co-existence of cepA and cfiA gene in B. fragilis species was seen. Based on the absence and presence of the cfiA gene, we divided B. fragilis into two categories, Division I (72.6%) and Division II (27.3%), respectively. CONCLUSION: AGNB acts as a reservoir of specific AMR genes, which may pose a threat to other anaerobes due to functional compatibility and acquisition of these genes. Thus, AST-complying standard guidelines must be performed periodically to monitor the local and institutional susceptibility trends, and rational therapeutic strategies must be adopted to direct empirical management.

Can beta-lactamase resistance genes in anaerobic Gram-negative gut bacteria transfer to gut aerobes?

The study was conceived with the hypothesis that human aerobic gut flora could act as a reservoir of ß-lactamases and contribute to the emergence of ß-lactam resistance by transferring ß-lactamase genes to resident anaerobes. Thus, we studied the repertoire of ß-lactam resistance determinants (ß-lactamases associated with aerobes and anaerobes) in Gram-negative anaerobes. The phenotypic resistance against ß-lactams and the presence of aerobic and anaerobic ß-lactamases were tested in Gram-negative anaerobic isolates (n = 200) by agar dilution method and targeted PCR, respectively. In addition, whole-genome sequencing (WGS) was used to study the ß-lactam resistance determinants in 4/200 multi-drug resistant (MDR) strains. The resistance to ß-lactams was as follows: imipenem (0.5%), cefoxitin (26.5%), and piperacillin-tazobactam (27.5%). None of the isolates showed the presence of ß-lactamases found in aerobic microorganisms. The presence of anaerobic ß-lactamase genes viz. cfiA, cepA, cfxA, cfiAIS [the intact segment containing cfiA gene (350 bp) and upstream IS elements (1.6-1.7 kb)] was detected in 10%, 9.5%, 21.5%, and 0% isolates, respectively. The WGS data showed the presence of cfiA, cfiA4, cfxA, cfxA2, cfxA3, cfxA4, cfxA5 in MDR strains. The study showed a distinct dichotomy in repertoires of ß-lactamases between aerobes and anaerobes.

Chronic Lower Limb Pain Unveiling a Rare Case of Spindle Cell Soft Tissue Sarcoma: A Diagnostic Odyssey.

Spindle cell soft tissue sarcomas are rare and challenging malignancies that tend to masquerade as benign conditions. This case report presents a 70-year-old female who sought medical attention due to persistent right lower limb pain and swelling over one year. Despite prior consultations at private clinics, her symptoms continued to progress. A tender, palpable swelling was noted upon examination, prompting further diagnostic investigations. Initial X-ray results yielded inconclusive findings, necessitating an MRI study with contrast. The MRI unveiled a substantial multi-lobulated spindle-shaped mass lesion exhibiting heterogeneous enhancement and altered signal intensity, measuring 7.3 x 2.5 x 2.2 centimeters. Additional nodular lesions in the periarticular region posterior to the ankle joint confirmed the diagnostic suspicion of spindle cell sarcoma, supported by orthopedic evaluation. Symptomatic management was initiated with analgesics and antibiotics, alongside a recommendation for biopsy. Histopathological examination of the biopsy specimen confirmed the presence of spindle cell soft tissue sarcoma under high magnification. This case underscores the diagnostic challenges of spindle cell sarcomas and the imperative role of a multidisciplinary approach in their accurate diagnosis and management.

Simultaneous Myasthenic Crisis With Thyrotoxic Crisis in an Adult Male: An Autoimmune Overlap.

When it comes to thyroid disorders, Graves' disease (GD) is the most prevalent autoimmune thyroid disorder in which antibodies are formed against thyroid receptors. Myasthenia gravis (MG) is a rare autoimmune neuromuscular junction disorder. Autoimmune antibodies are formed against postsynaptic neuromuscular junctions in MG, interrupting neuromuscular transmission and causing variable muscle weakness and tiredness. It affects older men and young women. The two disorders may coexist in a patient, or either of them may develop first. The thyroid condition GD is most frequently linked to MG. This case report describes an older man who presented with an acute exacerbation of MG along with a thyrotoxic crisis.

Post-traumatic Ruptured Scrotal Collection: Pyocele or Hematocele?

Ultrasound is the modality of choice for detecting the causes of acute scrotal pain and diagnosing scrotal pathologies. Pyocele is a term used for describing the purulent fluid collection in the scrotal sac, which may present to the hospital as a complication of testicular abscess, epididymal-orchitis, or post-trauma. Ultrasound is the modality of choice for diagnosing such pathologies. The presented case is of a young male from rural India who developed a pyocele post-trauma and underwent an ultrasound examination, where it was found to be a ruptured pyocele with contents spreading into the hemi-scrotum. Rupture of the tunica is frequently associated with the hematocele; however, pyocele is less commonly associated with rupture. The case report discusses the causes of pyocele, imaging features, management, and complications of this pathology along with other possible differential diagnosis.

A Rare Case of Obstructive Uropathy in an Elderly Male From Rural India - A Case Report.

Ureterocele is a rare congenital anomaly often believed to be caused due to incomplete dissolution of the Chwalla membrane. In this pathology, the distal end of the ureter is invaginated in the bladder and is dilated. We present a case of an 81-year-old male from rural India who came with complaints of hematuria and was diagnosed with ureterocele.

Role of Multidetector Computed Tomography Urography in the Evaluation of Obstructive Uropathy: A Review.

Obstructive uropathy, a prevalent clinical problem, can irreparably harm the kidneys if not treated promptly. As a result, accurate diagnosis is necessary for prompt management. This study examines the utility of multidetector computed tomography (MDCT) urography in identifying obstructive uropathy. PubMed, Google, Embase, Medline, and other electronic databases were used to search the English-language literature. The search phrases were obstructive urinary infections or urinary bladder or kidneys or MDCT. The authors' expertise and experience in the subject area aided in archiving pertinent publications. Even though the dilated upper tract of the ureters can be seen, ultrasonography (USG) has limitations because it cannot show the middle portion of the ureters, even if they are dilated mostly due to bowel gas artifacts. The USG does not emphasize the functioning of the renal tract. To evaluate obstructive uropathy, MDCT urography plays a very important role. For speedy, effective therapy, it provides a quick diagnosis of the source of obstruction.

Wandering Fibroid in a Post Menopausal Woman From Rural India: A Case Report.

Fibroids, also known as uterine leiomyomas, are the most common solid benign lesions of the uterus. Fibroids are responsive to hormones and are stimulated by estrogens and commonly grow during pregnancy and involute as menopause progresses. The treatment is mostly conservative. When symptomatic, the treatment requires surgical intervention. We present a case of a 72-year-old post-menopausal female with a large, calcified parasitic fibroid, an extremely rare variant of uterine leiomyoma occurring outside the uterus. The number of cases reported about this pathology is minimal.

Absent Thumb and Radius in a Neonate With Tracheo-Esophageal Fistula and Ventricular Septal Defect: VACTERL Association.

A complex of anomalies involving the vertebral column and spinal canal (V), anal atresia(A), congenital lesions of the heart (C), defects involving the trachea esophageal complex (TE), renal system, and urinary tract (R), and limb lesions (L) is known as VACTERL complex. VACTERL is an umbrella term for patients with abnormalities involving three or more of the systems mentioned above. It can be potentially life-threatening and should be promptly recognized and managed. Thorough investigations are required to prevent long-term sequelae and to improve morbidity. We present a case of a neonate born to a mother with twin gestation at 38 weeks of gestation with antenatally diagnosed severe polyhydramnios and a single umbilical artery and vein. This manuscript discusses the imaging findings of the congenital abnormalities involving the cardiac and skeletal system with tracheoesophageal fistula in our patient.

Lemierre Syndrome Presenting as Tender Goiter.

Internal jugular vein (IJV) thrombosis, also known as Lemierre syndrome (LS), is a potentially dangerous complication that follows oropharyngeal infections. It has also been documented in individuals with cervical lymph node infection, thyroid abscess, and pharyngeal abscess. LS is potentially a catastrophic complication and, if not detected and treated early, can lead to mortality. This case report describes an older woman who presented with a history of fever, odynophagia, and swelling in the anterior aspect of her neck for 20 days. Examination revealed a severely congested posterior pharyngeal wall with bilateral tonsillitis and a tender goiter. Further investigations revealed a diagnosis of LS. The patient was appropriately managed with higher antibiotics and anticoagulation. This case report highlights the importance of IJV thrombosis, which can present as a thyroid swelling.