Slackia exigua, an emerging anaerobic pathogen - isolation from a case of polymicrobial peritonitis and review of literature.

Intra-abdominal infections (IAI) are surgical emergencies ranging from appendicitis to peritonitis and intrahepatic infections. Anaerobic bacteria including Bacteroides spp. and Clostridium spp. cause 30-50 % of these infections. Slackia exigua (S.exigua) is an obligate anaerobe part of the human oral microbiota and has been associated with periodontal problems. In this report, we describe a rare occurrence of polymicrobial infection with four anaerobes including S. exigua in a patient with peritonitis caused by a hidden ileal perforation.

Veillonella atypica causing retropharyngeal abscess: A rare case presentation.

Veillonella species are obligate anaerobes which are part of the human oral, gut and vaginal microbiota. The genus Veillonella consists of 16 characterized species. Very few infections due to Veillonella atypica have been reported till date. Here we present a case of retropharyngeal abscess due to this organism in a 55-year-old lady.

Molecular study on metronidazole resistance in Bacteroides fragilis group isolates from a South Indian tertiary care center.

OBJECTIVE: Bacteroides species are an important part of human intestinal microbiota. They can cause infections of significant mortality and morbidity when moved out of their niche in the gut. The cornerstone drug for prophylaxis and therapy, metronidazole, is exhibiting signs of resistance, which are frequently attributed to nitroimidazole (nim) resistance genes. The aim of this study was to use Epsilometer test (E-test) to assess the metronidazole susceptibility and conventional PCR methodology to map the distribution of nim genes in Bacteroides fragilis group (BFG) isolates. METHODS: MALDI-TOF MS was used to identify BFG isolates. Using the E-test methodology, metronidazole minimum inhibitory concentrations (MICs) were determined. The presence of nim genes in these isolates were checked by conventional PCR methodology. Sequencing was done on selected amplicons for determining the nim gene types. RESULTS: Bacteroides fragilis accounted for 55.3% of the total 273 BFG members identified. Of these, 196 (71.8%) were susceptible, 43 (15.8%) intermediate and 34 (12.5%) resistant to metronidazole as determined by the E-test. nim gene was present in 101 (37%) of the total 273 isolates. Out of the 34 phenotypically resistant isolates (MIC ≥32 µg/ml), 29 harboured nim gene (Chi-square test, p < 0.0000001) but nim gene was absent in 5 (14.7%) isolates. Also, nim gene was detected in 72 (30.1%) of the 239 isolates with susceptible and intermediate metronidazole MIC. Sequencing of 20 amplicons gave a nimE gene type. CONCLUSIONS: In view of the rising metronidazole resistance among BFG and its close association with nim genes, there is a need for implementing routine metronidazole susceptibility testing and more researches are needed to find the molecular basis of these nim genes.

Intra-spinal abscess due to Bacteroides fragilis and Klebsiella pneumoniae co-infection in a child with spinal dysraphism.

Bacteroides fragilis (B. fragilis) is an uncommon cause of spinal abscess. We present a case of an 18-month-old child, with spinal dysraphism-Spina bifida occulta, who developed intra-spinal abscess infection with B. fragilis and Klebsiella pneumoniae. Magnetic resonance imaging (MRI) of the brain and spine showed multiple abscesses extending through the presacral fistula into the spinal cord. Patient was surgically treated along with administration of antimicrobial agents (ceftriaxone and metronidazole), resulting in an excellent clinical outcome.

Prevotella oris: A lesser known etiological agent of pleural effusion.

Prevotella are gram negative, obligate anaerobes and includes pigmented and non-pigmented species. They are typically regarded as commensals, especially of the gastrointestinal tract and oral cavity, although opportunistic endogenous infections are known to be caused by a small number of strains. We report a case of a 51-year-old man with right-sided chest pain. Chest X-ray showed mild haziness in the right lung and he was diagnosed with right sided pleural effusion. Prevotella oris was isolated after pleural pus culture.

Detection of Entamoeba histolytica and bacterial etiological agents in patients with clinically suspected cases of liver abscesses.

Liver abscess is one of the conditions having multiple etiological agents. It can be parasitic or can be due to bacterial among other causes. Entamoeba histolytica is one of the common protozoan parasites causing amoebic liver abscess. So, accurate diagnosis is important for proper management and treatment. We have tried to detect the various bacterial etiological agents along with Entamoeba histolytica using culture of bacteria and polymerase chain reaction for E. histolytica in suspected liver abscess cases. Liver aspirates/pus collected from 63 patients were subjected to bacterial gram staining and culture along with wet mount and PCR for E. histolytica. Patients' clinical details and outcomes were also noted and co-related.It was seen that 22 (34.9%) out of 63 samples showed the presence of bacteria by gram staining whereas aerobic bacterial growth was seen in 28.6% and only 1.6% in anaerobic culture. Amoebic liver abscess showed E. histolytica  in 36 patients out of 63 study participants (57.1%) by PCR. The study showed that 44.4% of patients had a habit of alcohol consumption and 19.1% were chronic smokers. Abdominal pain (90.3%) was the most common presenting feature followed by fever (64.5%). The most common co-morbidities in the enrolled patients was diabetes mellitus (19.3%) and least with chronic liver disease (3.2%). Liver abscess, a multi-etiological condition needs a robust diagnostic method. Just a single method or a single sample type is not sufficient to diagnose, as it may miss out other causes. Treating its associated co-morbidities may help to lessen it.

Bacteremia due to obligate anaerobes following large bowel surgery in a tertiary care hospital in South India.

In view of the rising incidence of Anaerobic bacteremia(AB), the use of anaerobic blood culture bottles have been recommended in addition to the aerobic blood culture bottles. The need to perform antimicrobial susceptibility testing(AST) for anaerobes has become mandatory owing to increasing metronidazole resistance. The frequency of AB following large bowel surgery and the metronidazole susceptibility for members of the Bacteroides fragilis group were determined. The incidence of AB was found to be 16%. Seventeen obligate anaerobes were isolated in total, of which B. fragilis was the most common. Two of twelve isolates of B. fragilis were resistant to metronidazole.

Clostridioides difficile Diarrhea: An Emerging Problem in a South Indian Tertiary Care Hospital.

Context Clostridioides difficile infection (CDI) is one of the most common infectious causes of hospital-acquired diarrhea. The actual burden of the disease is underestimated in India due to inadequate diagnostic methods and limited studies conducted. Aims The aim of this study was to determine the burden and risk factors of CDI among patients with hospital-acquired diarrhea. Methods and Materials Stool specimen of patients (age > 1 year) with hospital-acquired diarrhea were screened for glutamate dehydrogenase antigen and toxin using an enzyme immunoassay. If both antigen and toxin were present, it was reported as positive for toxigenic CDI. Samples positive for antigen and negative for toxin were further tested with Cepheid GeneXpert assay for detecting the toxin producing gene. Results Of 75 patients (mean age 36.07 ± 20.79, 64% males), 14 (18.67%) patients were positive for toxigenic Clostridioides difficile ( C. difficile ) and 3 (4%) patients were nontoxigenic C. difficile . Addition of GeneXpert to the testing algorithm increased the yield of toxin detection in 5/14 patients who were negative by toxin assay. On analysis of risk factors, prolonged hospital stay was found to have significant association ( p -value = 0.022). Patients with factors like intensive care unit stay, presence of diabetes mellitus as a comorbidity, and exposure to antibiotics like carbapenems and glycopeptides have been found to have a higher prevalence of CDI. Conclusions The prevalence of CDI in our population was 18.67% and the major risk factor associated was prolonged hospital stay. The addition of GeneXpert for the detection of toxin gene increased the yield from 12 to 18.68%.

Pathogenic potential of Parabacteroides distasonis revealed in a splenic abscess case: a truth unfolded.

Splenic abscess is a rare entity, however if unrecognised or left untreated, it is invariably fatal. We herein report a case of splenic abscess in a 40-year-old man presenting with fever, left-sided abdominal pain, altered sensorium and vomiting. On clinical examination, hepatosplenomegaly was noted and the ultrasound of the abdomen showed multiple hypoechoic regions in the upper pole of spleen, and the diagnosis of splenic abscess was made. The patient received antimicrobial therapy and underwent an open splenectomy with full recovery. Pus aspirated from the splenic abscess grew an unusual organism named Parabacteroides distasonis In the literature, there are only a few recorded cases of P. distasonis causing splenic abscess. Through this case report, we would like to emphasise the pathogenic role of P. distasonis in causing clinical disease, as this organism is typically known to constitute a part of the normal flora.

Uncommon isolation of Desulfovibrio vulgaris from a depressed fracture wound on the forehead.

Desulfovibrio spp. are gram negative, obligate anaerobes capable of reducing sulfate. They have caused infections in humans, but very rarely. They are slow growers and difficult to identify. Hence, they are often overlooked and their actual presence goes unnoticed. Here, we describe a case of a 15- year old boy who was involved in a road traffic accident and he presented with seropurulent discharge from a depressed fracture wound on the forehead. Desulfovibrio vulgaris (D.vulgaris), was isolated from the pus discharge, the first to be reported. The characteristic desulfoviridin pigment production in the organism aided in the identification. The infection was successfully managed with pain reliever and course of amoxicillin - clavulanic acid and linezolid.

Intracranial abscess due to Prevotella bivia: First case report from India.

The association of Prevotella bivia (P. bivia), a Gram negative obligate anaerobic bacillus with brain abscess has been rarely reported. We hereby, report a case of brain abscess in a 50-year-old man, who suffered a head trauma followed by decompression surgery 10 months ago. Aspirated pus sample grew Methicillin resistant Staphylococcus aureus (MRSA) and P. bivia sensitive to metronidazole. The patient recovered well after a brain abscess evacuation surgery and post-operative metronidazole therapy, confirming the pathogenic role of P. bivia in this case.

Rare isolation of Fusobacterium varium from a case of Fournier's gangrene.

Fusobacterium is a gram negative obligate anaerobic bacilli, a normal inhabitant of gastrointestinal tract, oropharynx and female genital tract. Here we report a case of Fourniers gangrene from which Fusobacterium varium has been isolated along with certain other pathogens. There are only a few reported cases of Fusobacterium varium in literature and it has never been reported from Fournier's gangrene. Through this report we intend to shed some light on the pathogenic potential of anaerobes which are considered as normal flora.

Clinico-microbiological Profile of Septic Diabetic Foot with Special Reference to Anaerobic Infection.

Introduction Diabetic foot infections are a major cause of non-traumatic amputations. The role of anaerobes in the prognosis of these infections is particularly unclear. This study was conducted with the aim of correlating microbiological profiles with clinical outcomes in these diabetic foot ulcer patients. Methodology This prospective observational study was done in a tertiary care centre in South India. All patients admitted with diabetic foot ulcers for two years were included in the study. Tissue biopsies were collected from the ulcer for aerobic and anaerobic cultures. The patients were grouped as those with aerobic infection alone (anaerobe negative) and those with mixed aerobic and anaerobic infections (anaerobe positive). Anaerobic culture was performed using the Robertson cooked meat (RCM) medium. The ulcer of the foot was described with respect to site, size, duration, history of previous amputation(s), and history of number and class of antibiotic intake prior to hospitalization. Clinical course and Wagner's grades of the diabetic foot ulcers were compared for aerobic and anaerobic infections. Results A total of 104 patients were included in the study. There were no significant differences between the two groups with regards to duration of diabetes, random blood sugar (RBS) at the time of admission, compliance to drugs, and mode of blood sugar control and prior intake of antibiotics. Patients with anaerobic infections were found to have a higher incidence of fever in this study (38.1% vs. 14.5%; p = 0.0057), as compared to patients with aerobic infections. More than half of the patients in the anaerobic infection group presented with Wagner's grade IV and above, as compared to the aerobic infection group (59.5% vs. 32.2%; p = 0.0059), which was statistically significant. Patients with anaerobic infections also had high numbers of major and minor amputations when compared to patients with aerobic infections. Conclusion Septic diabetic foot patients with fever at the time of admission and a high Wagner's grade have a greater chance of harbouring anaerobic infections. Drugs for anaerobic coverage should be considered for wounds beyond Wagner's grade III. Anaerobic infections resulted in increased risk of morbidity in diabetic foot ulcer patients but did not have any influence on mortality.

Brain abscess and cervical lymphadenitis due to Paraclostridium bifermentans: A report of two cases.

Paraclostridium bifermentans (current nomenclature of Clostridium bifermentans since 2016) is a gram-positive, spore-forming anaerobic bacterium. Here, we describe two cases associated with this organism. The first, primarily a case of tubercular brain abscess where P. bifermentans was isolated as part of a polymicrobial flora, following a neurosurgical procedure for the same and the second, a case of cervical lymphadenitis from which it was isolated as the sole causative agent. There are only a few reported cases of P. bifermentans in literature and these cases illustrate the widening spectrum of infections related to it.

Clostridium perfringens - A bacterial pathogen gaining recognition in necrotizing pancreatitis.

We report an interesting case of necrotizing pancreatitis due to Clostridium perfringens in an elderly man who came to the hospital with complaints of severe abdominal pain. The infection further worsened with the dissemination to other internal organs. The patient did not show any improvement despite intensive care and treatment. This emphasizies the fact that early diagnosis and appropriate treatment would reduce the morbidity associated with necrotizing pancreatitis.

Tuberculous cerebellar abscess in immunocompetent individuals.

Tubercular abscess of the brain is a rare form of central nervous system tuberculosis. These lesions usually occur in the supratentorial compartment. They are associated with a state of immune deficiency. We report two immunocompetent individuals with tubercular abscess of the cerebellum and discuss the management of these lesions.

A rapid slide agglutination test for the diagnosis of neurocysticercosis in the rural health set up.

BACKGROUND: Simple and rapid latex-based diagnostic tests have been used for detecting specific antigens or antibodies in several diseases. AIMS: The aim of the present study was to standardize and evaluate the latex agglutination test (LAT) for the detection of Taenia solium metacestode antigen in the cerebrospinal fluid (CSF) and serum for the diagnosis of neurocysticercosis (NCC). SETTINGS AND DESIGN: The study was conducted at Department of Microbiology, Jawaharlal Institute of Post graduate medical education and research after obtaining informed consent from the study subjects. MATERIALS AND METHODS: In the present study, CSF and serum samples were collected from clinically suspected NCC, CT/MRI proven cases of NCC, non-cysticercal central nervous system infection control and from healthy control subjects. CSF was not collected from healthy controls. Polyclonal antisera raised in rabbits against porcine T. solium metacestode complete homogenate antigen, was used in the LAT to detect the antigen in the specimens. STATISTICAL ANALYSIS USED: The statistical analysis was carried out using Epi Info. The sensitivity, specificity, positive predictive value, and negative predictive value of the LAT were calculated. RESULTS: The LAT exhibited sensitivity of 64.7% and specificity of 85.7% with CSF samples and sensitivity of 52.08% and specificity of 96% with serum samples. CONCLUSIONS: Results of the present study shows that the LAT can be employed as a moderately sensitive and specific test for the detection of T. solium metacestode antigen in the CSF and serum specimens for the diagnosis of NCC in poorly equipped laboratories.

Acute osteomyelitis caused by Rhodococcus equi in an immunocompetent child.

Rhodococcus equi is an unusual pathogen causing infections mostly in immunocompromised patients, particularly in those with human immunodeficiency virus (HIV). It has rarely been reported to affect immunocompetent hosts, where it usually presents as an isolated extrapulmonary lesion. We report a case of osteomyelitis caused by this organism in an immunocompetent host.

Detection of specific cysticercus antigen in the urine for diagnosis of neurocysticercosis.

Neurocysticercosis (NCC) is an important zoonotic infection, and a significant cause of morbidity and mortality in India. Immunodiagnosis plays an important role in the early, rapid, and specific diagnosis of the condition. The aim of the present study was to detect specific cysticercal antigen excreted in the urine for the diagnosis of NCC. The objective was to develop and evaluate staphylococcal Co-agglutination (Co-A) test for the detection of urinary cysticercal antigen. In the present study, urine samples were collected from 9 cases of clinically suspected NCC, 8 cases of CT/MRI proven cases of NCC, 11 of non-cysticercal CNS infection controls, and 25 healthy control subjects. Polyclonal antisera raised in rabbits against porcine complete cysticercus homogenate antigen, was used in the Co-A test to detect cysticercal antigen. The Co-A detected excreted cysticercal antigen in the urine of five of nine (55.5%) clinically diagnosed NCC and in five of eight (62.5%), CT/MRI proven cases of NCC. A false positive reaction was observed with 1 of 11 (9%) of control urine specimens from non-cysticercal CNS infection controls. No false positivity was demonstrated with 25 urine samples collected from healthy controls. Results of the present study shows that the Co-A test can be employed as a moderately sensitive and specific test for detection of urinary antigen in the diagnosis of NCC in poorly equipped laboratories.