Utility of bone marrow examination (BME) in the diagnosis of pyrexia of unknown origin (PUO).

INTRODUCTION: Bone marrow examination (BME) is a useful tool in the diagnosis of haematological and non-haematological diseases. It plays an important role in early diagnosis of the underlying cause of pyrexia of unknown origin (PUO) and can influence the management of patients. Bone marrow aspiration (BMA) plays a very important role in establishing a definitive diagnosis in cases of PUO. The aim of this study was to review the indications and usefulness of bone marrow aspirates sent for microbiological evaluation as a diagnostic tool with histopathological correlation. METHODOLOGY: A prospective study was conducted from 1 January 2017 to 30 September 2019 in the Department of Microbiology and Pathology on the bone marrow aspirates of patients of all groups. RESULTS: A total of 148 bone marrow aspirates were included. The cases were categorized as classical PUO (n = 81/148, 54.7%), nosocomial PUO (n = 4 /148, 2.7%), neutropenic PUO (n = 18/148, 12.1%), and immunocompromised PUO (n = 45/148, 30.4%), among which were systemic lupus erythematosus cases n = 8/45 (22.2%), human immunodeficiency virus positive cases n = 10/45 (17.7%), and renal transplant cases n = 27/45 (60%). A total of 28 BMAs were positive for microorganisms, out of which bacterial pathogens were n = 12 (42.8%), mycobacterial n = 12, 42.8%, fungal (n = 3, 10.7 %), and viruses (n = 1, 3.5%). CONCLUSIONS: This study helped in highlighting the role of bone marrow examination as an important diagnostic method in the diagnosis of infectious diseases.

Clinical and microbiological spectrum of external ventricular drain related infections (EVDRIs) from a tertiary care center.

Background and Objectives: Insertion of an External Ventricular Drain (EVD) is a common and important lifesaving procedure that can lead to morbidity and mortality. This study was conducted to assess the infection rate, risk factors, causative organisms, and outcome of EVDs. Materials and Methods: A prospective study was undertaken in a tertiary care centre from August 1st to October 30th, 2020. Over 192 patients had undergone insertion of EVDs in the neurosurgical intensive care unit. CSF samples were collected in sterile containers and transported to the laboratory. Results: A total of 214 EVDs were inserted in 192 patients for 691 days. The median duration for EVD in situ and the mean time between catheter insertion and onset of infection were 14.5 days and 8 days. EVD related infection rate was 19.4 for 1000 EVD days. The most common risk factor for EVD insertion were tumors (55%) followed by hydrocephalus (40%).We identified 25 patients out of 192 (12%) who had clinical signs and symptoms with deranged CSF counts. A total of 13/25 (52%) specimens were culture positives out of which 10 (76.9%) were Gram negative pathogens and 3 (23%) were Gram positive pathogens and 3/10 (30%) Gram negative pathogens were Multidrug resistant organisms (MDROs). Conclusion: It was observed that longer duration of catheter in situ was an important risk factor for EVD-related infections (ERIs) and also higher frequency of CSF sampling. A proper EVD infection prevention and control protocol must be followed in the form of a checklist at the time of EVD insertion.

Prevalence of scrub typhus in a tertiary care centre in Telangana, south India.

BACKGROUND AND OBJECTIVES: Scrub typhus is re-emerging as an important cause of acute undifferentiated fever in the last decade from various parts of India. Complexity in performing the "gold standard" immunofluorescent assay and the unreliable nature of Weil Felix test often results in delayed or misdiagnosis in a majority of cases. The present study seeks to integrate the results of rapid diagnostic tests, clinical and laboratory features to aid the diagnosis and management of scrub typhus patients. MATERIALS AND METHODS: A total of 645 serum samples with suspected scrub typhus sent to the Department of Microbiology were included in the study. Scrub typhus was tested by rapid immunochromatographic test (SD Diagnostics) and IgM ELISA (Inbios International, USA). Clinical features, laboratory parameters and final outcome were analysed from the clinical records of positive patients. RESULTS: Scrub typhus was diagnosed in 13.7% of patients and majority of them were observed in the month of August. 58.6% of scrub typhus patients presented with fever of one to two weeks duration. Eschar was documented in 13.7% of patients and 24% of patients gave a history of working outdoors or exposure to vegetation. All the patients responded to Doxycycline treatment and there was no mortality. CONCLUSION: High index of suspicion for scrub typhus is necessary in febrile patients not responding to conventional antibiotics especially during outbreak situations. Rapid immunochromatographic tests with excellent specificity and acceptable sensitivity can be used as potential point of care tests for quick diagnosis of scrub typhus especially in delayed presentation.

Direct Detection and Discrimination of Carbapenemases of Acinetobacter baumannii from Uncultured Tracheal Aspirates.

Carbapenemases play important roles in conferring resistance to beta-lactam antibiotics, including the carbapenems. Detection of carbapenemase activity helps to understand the possible mechanism(s) of carbapenem resistance. Identification of carbapenemases is currently being done by various phenotypic methods and molecular methods. However, innovative biochemical and spectrophotometric methods are desirable as they will be easy to perform, affordable, and rapid. A novel chromogenic method called Carba NP test was introduced recently to screen for carbapenemases in clinical isolates of gram-negative pathogens. We adopted this assay (1) to detect the total carbapenemase activity, (2) to discriminate Class A, B, and D carbapenemases with inhibitors, (3) to compare with carbapenemase genotype, and (4) for direct differential diagnosis of carbapenemases in uncultured clinical sample such as tracheal aspirate. The study included 132 purulent tracheal aspirates. All samples were processed and screened by a protocol optimized in our laboratory, which showed good sensitivity and correlation with genotyping and conventional phenotyping. Our protocol not only offers the fastest way to identify the pathogen but also its carbapenemase profile, directly from uncultured clinical samples in less than 4 hr. Our protocol is currently being validated on other types of clinical specimens in our laboratory.

Mucormycosis due to Apophysomyces species complex- 25 years' experience at a tertiary care hospital in southern India.

Apophysomyces elegans species complex is an important cause of cutaneous mucormycosis in India. However, majority of those cases are reported as case reports only. We desired to analyze our patients with Apophysomyces infection reported over 25 years (1992-2017) to understand the epidemiology, management, and outcome of the disease. During the study period 24 cases were reported, and the majority (95.8%) of them presented with necrotizing fasciitis following accidental/surgical/iatrogenic trauma. One patient presented with continuous ambulatory peritoneal dialysis (CAPD) related peritonitis. Healthcare related Apophysomyces infection was noted in 29.2% patients. In addition to trauma, comorbidities were noted in 37.5% patients (type 2diabetes mellitus-6, chronic alcoholism-2, and chronic kidney disease-1). Of the 24 isolates, 11 isolates starting from year 2014 were identified as Apophysomyces variabilis by molecular methods. Majority (95.8%) of the patients were managed surgically with or without amphotericin B deoxycholate therapy, while one patient was treated with amphotericin B deoxycholate alone. Among 24 patients, seven (29.1%) recovered, six (25%) patients could not afford antifungal management and left the hospital against medical advice, and 11 (45.9%) patients died.The present case series highlights that necrotizing fasciitis caused by A. variabilis is prevalent in India, and the disease may be healthcare related. Although diagnosis is not difficult, awareness among surgeons is still limited about the infection, leading to a delay in sending samples to the mycology laboratory. Apophysomyces infection must be considered in the differential diagnosis in apatient with progressive necrosis of a wound who is not responding to antibacterial therapy.

Extraintestinal infections caused by nontyphoidal Salmonella from a tertiary care center in India.

BACKGROUND: Infection with Salmonella has become an increasing problem worldwide. Recently, nontyphoid Salmonella (NTS) has become a global concern causing threat to the health of human. It causes gastrointestinal infection which may be self-limiting, but invasive infections may be fatal, requiring appropriate therapy. This study was done to analyze the spectrum of NTS infections causing extraintestinal infections and its susceptibility pattern from a tertiary care center in India. MATERIALS AND METHODS: The medical records of 27 patients whose cultures were positive for NTS between the years 2013-2016 were included in this retrospective study. The relevant demographic, clinical, and laboratory data were analyzed. RESULTS: Among the 27 patients, predominant patients were in the age group of 20-30 years. The male to female ratio is 1.7:1. Salmonella typhimurium was the predominant NTS isolated among 15/27 (55.5%), followed by Salmonella enteritidis 4/27 (14.8%). 18/27 (66.6%) of NTS were isolated from blood. Nalidixic acid was sensitive in 2/15 of S. typhimurium, 2/4 of S. enteritidis and 1/3 of Salmonella weltevreden, while others are nalidixic acid-resistant implying resistance to quinolones. They were sensitive to other antibiotics reported. CONCLUSION: This study highlights the spectrum of NTS causing extraintestinal infections which is an emerging infection occurring mostly in immunosuppressed individuals. There should be a high degree of clinical suspicion which would help in the early diagnosis and management of patients.

Bacteriological profile of intra-abdominal infections in a tertiary care hospital.

BACKGROUND AND OBJECTIVES: Intra-abdominal infections (IAIs) include a wide spectrum of pathological conditions, ranging from uncomplicated appendicitis to fecal peritonitis .The resulting infections should be diagnosed early and treated based on the organism isolated and its susceptibility. In this study the bacteriological profile and antimicrobial resistance pattern of intra-abdominal infections was analyzed. MATERIALS AND METHODS: A retrospective analysis of samples received from 119 cases of intra-abdominal infections in our Institute from January 2015 to December 2017 was analyzed. Patients with primary peritonitis from cirrhosis or ascites were not included in the study. The specimens were primarily processed, as per standard methods. Identification and antimicrobial susceptibility testing was done by the Vitek-2 system. Anaerobic culture was performed on 5% sheep blood agar plates and incubated in GEN bag anaerobic pouches. RESULTS: In our study perforative peritonitis 43/119 (36.1%) was predominant IAI followed by acute pancreatitis 14/119 (11.7%) and pancreatic necrosis 12/119 (10%). Microbial growth was observed in 66.3% (79/119) of the cases and combined infections were observed in14/119 (11.7%) of the cases. Escherichia coli was the predominant organism isolated in 58/119 (40.8%), out of which 41/58 (70.6%) were ESBL producers and 16/58 (27.5%) were multi drug resistant isolates. Klebsiella pneumoniae was isolated from 11/119 (9.2%) cases out of which 8/11 (72.7%) were ESBL and 3/11 (27.2%) were multidrug resistant isolates. Post-operative complications was observed in 12/119 (10%) patients with mortality in 15/119 (12.6%) patients. CONCLUSION: Early diagnosis and appropriate management of the infections will help to prevent the morbidity and mortality associated with these infections.

Need for appropriate specimen for microbiology diagnosis of chronic osteomyelitis.

INTRODUCTION: Chronic osteomyelitis (COM) is a common infection, especially in developing countries. An adequate bone biopsy specimen processed with appropriate microbiology culture methods for isolation and identification of the causative organisms is considered as the gold standard for the diagnosis of osteomyelitis. MATERIALS AND METHODS: The present study is a retrospective microbiology analysis of the specimen from 219 clinically diagnosed cases of COM between January 2013 and April 2016. RESULTS: The overall culture positivity was 111/219 (50. 6%), colonization was seen in 22/219 (10.5%), while the rest 86/219 (39.3%) were culture-negative specimen; culture positivity was highest from tissue specimen (71/113, 62.8%). Among the swabs, 40/106 (37.7%) were culture positive. About 28/40 (70%) culture-positive swabs showed significant growth of Gram-positive organisms. Colonization with skin flora such as diphtheroids and Coagulase-negative Staphylococci was seen in 22/106 (20.7%) of the swabs. Sterile cultures (44/106, 41.6%) were high among the swab specimen. Gram-positives were most common (75/111, 67.56%). Staphylococcus aureus was the predominant organism isolated in 70/111 (63%) cases. Gram-negative bacilli showed a high level of antibiotic resistance. CONCLUSION: As per our data, the culture yield from wound swabs was low or contaminated with normal skin flora, as compared to the biopsy or tissue specimen. Hence, an appropriate sampling of the infected bone using recommended protocols is highly essential for improving microbiological yield and the outcome of COM.

Aerobic bacteriological profile and antimicrobial susceptibility pattern of pus isolates from tertiary care hospital in India.

INTRODUCTION: Pyogenic infections are an important cause of sepsis. These infections are difficult to treat because of the pathogens with increasing antibiotic resistance. It is important to know the pathogens causing the infections and its antibiotic susceptibility for proper management of the patients. METHODOLOGY: A retrospective analysis of 1428 culture positive pus and tissue samples received in the department of microbiology from various departments in the hospital between January 2012 to 2017 was performed. Data regarding the pathogen isolated and its antimicrobial susceptibility were collected and analyzed. The specimens were primarily processed, as per standard methods. Identification and susceptibility testing was done using the Vitek-2C system. RESULTS: Among the samples males outnumbered females (M: F-2.5:1) and the median age was 47 years. The total number of patients were 1428 with total number of isolates being 1525 as in our study monomicrobial infections were seen in 93.2% (1331/1428) patients whereas combined infections with growth of two pathogens in 6.8% (97/1428). Gram-negative bacilli were isolated in 68.3% (1042/1525). Among the Gram-negative bacilli Escherichia coli was the major pathogen isolated (38.6%, 403/1042). Gram positive organisms were isolated in 31.6% (483/1525) of cases and Staphylococcus aureus was the predominant organism isolated (91.7%, 443/483). Rare pathogens like Burkholderia pseudomallei in 3 patients and Nocardia in one patient were also isolated. CONCLUSION: This study emphasizes to understand the common organisms isolated from wound infections and it helps in empirical treatment of patients based on antibiotic susceptibility patterns.

Isolation of the Rare Opportunistic Yeast Saprochaete capitata from Clinical Samples-Experience from a Tertiary Care Hospital in Southern India and a Brief Review of the Literature.

INTRODUCTION: Saprochaete capitata (Teleomorph: Magnusiomyces capitatus) is a ubiquitous yeast found in environmental sources such as soil, water, air, plants and dairy products. It is also a part of the normal microbial flora in humans. The yeast is being increasingly reported as an opportunistic pathogen, especially in patients in the haemato-oncology setting, the infection being often mistakenly diagnosed as invasive candidiasis. AIM: To review the epidemiological, clinical and microbiological features of six patients admitted in our hospital over a period of 10 years (from January 2007 to December 2016), from whom Saprochaete capitata was isolated. MATERIALS AND METHODS: A retrospective study was conducted and the epidemiological, clinical, imaging and microbiological data of the six patients were collected and analysed. RESULTS: The age of the six patients ranged from 19 years to 65 years with a median age of 53 years. There were two males and four females. In three out of the six patients, the isolation of S. capitata was considered clinically significant as the yeast was isolated repeatedly from blood and/or respiratory specimens and the clinical features could not be explained by any other alternative diagnosis. Haematological malignancy was the underlying disease in three out of the six patients while one patient was on triple immunosuppression following renal transplantation four years back. Three out of the six patients had severe neutropenia with Absolute Neutrophil Count (ANC) ≤ 500 at the time of isolation of S. capitata. Two patients with clinical features of fungal sepsis received antifungal therapy with Amphotericin B but succumbed within a short period of starting the therapy. The post renal transplant patient who presented with pneumonia recovered after treatment with a combination of Amphotericin B and Voriconazole. CONCLUSION: Awareness regarding the epidemiological, clinical and microbiological aspects of invasive infections caused by S. capitata is essential for early recognition and appropriate management.

Clinicomicrobiological spectrum of infective endocarditis - from a tertiary care centre in south India.

BACKGROUND AND OBJECTIVES: Infective endocarditis (IE) is a microbial infection of the endothelial surface of the cardiac-valves. Rapid diagnosis, effective treatment and prompt recognition of complications are essential, in order to improve the outcome. We retrospectively reviewed and determined the clinical characteristics, microbiological profile and management strategies of IE cases, changing microbial spectrum of pathogens and outcome in Native Valve Endocarditis (NVE) and Prosthetic Valve Endocarditis (PVE) cases. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 191 patients, clinically diagnosed with IE, based on modified Dukes criteria, from January 2011 to December 2016. Blood cultures received from all these patients were processed, using BacT/Alert system (bioMerieux, Marcy l'Etoile, France). RESULTS: Sixty eight (68/191) cases were positive for bacterial pathogens. Twenty four (24/191) cases had PVE and 167/191 had NVE. Nineteen cases (19/24, 79.1%) were PVE positive and forty nine (49/167, 29.3%) were NVE positive. Culture negative endocarditis cases were 123/191 (64.39%). The most common pathogen isolated from NVE cases, in our study was Streptococcus mitis, followed by methicillin-resistant coagulase negative staphylococcus (MRCONS) in PVE. The NVE were treated intravenously with a combination of a ß-lactam or glycopeptide with an aminoglycoside, for prolonged period of 4-6 weeks, with a successful outcome. The PVE cases were treated with the appropriate antibiotics as per the antibiotic susceptibility report. CONCLUSION: The high morbidity and mortality rates are associated with IE and hence accurate identification of aetiological agents and appropriate antimicrobial therapy is required.

Anaerobic brain abscess.

BACKGROUND AND OBJECTIVES: Brain abscess remains a potentially fatal central nervous system (CNS) disease, especially in developing countries. Anaerobic abscess is difficult to diagnose because of cumbersome procedures associated with the isolation of anaerobes. MATERIALS AND METHODS: This is a hospital-based retrospective microbiological analysis of 430 brain abscess materials (purulent aspirates and/or tissue), for anaerobic organisms, that were received between 1987-2014, by the Microbiology Laboratory in our Institute. RESULTS: Culture showed growth of bacteria 116/430 (27%) of the cases of which anaerobes were isolated in 48/116 (41.1%) of the cases. Peptostreptococcus (51.4 %), was the predominant organism isolated in four cases followed by Bacteroides and Peptococcus species. CONCLUSION: Early diagnosis and detection of these organisms would help in the appropriate management of these patients.

Evaluation of LAMP Assay Using Phenotypic Tests and Conventional PCR for Detection of nuc and mecA genes Among Clinical Isolates of Staphylococcus spp.

INTRODUCTION: The purpose of this study is to develop a nuc and mecA gene specific Loop-mediated isothermal Amplification (LAMP) assay for rapid identification and detection of methicillin resistant Staphylococcus aureus among clinical isolates. MATERIALS AND METHODS: A total of 100 (70 from pus and 30 from blood), clinical isolates of Staphylococcus spp were screened for the nuc gene to differentiate between S.aureus and Coagulase negative Staphylococci (CONS) by a nuc gene specific LAMP assay. The isolates were also screened for the presence of the mec Agene by the mecA specific LAMP assay. The results were compared with the phenotypic identification and methicillin resistance by Vitek-2 system (bioMérieux, Marcy l'Etoile, France) and conventional PCR. RESULTS: Among 100 Staphylococcus isolates, there were 82 (82%) Staphylococcus aureus isolates and 18 (18%) coagulase negative Staphylococcus as detected by the Vitek 2, conventional PCR and the LAMP assay using the nuc gene. The mecA gene was detected by the LAMP assay in 56(56%) isolates (44 Methicillin resistant Staphylococcus aureus (MRSA) and 12 Methicillin resistant coagulase negative Staphylococcus (MRCONS), which were also identified by the Vitek 2 and conventional PCR as methicillin resistant. The results of the LAMP assay were available within 90min as compared to the Vitek 2 results (18- 24hours) and conventional PCR (3-4 hours). CONCLUSION: The present study proved that LAMP assay can be used for the simultaneous differentiation of Staphylococcal spp and detection of methicillin resistance.

Unusual Presentation of Melioidosis in a Case of Pseudoaneurysm of Descending Thoracic Aorta: Review of Two Case Reports.

INTRODUCTION: Melioidosis is a rapidly fatal infectious disease caused by Burkholderia pseudomallei, an agent of potential biothreat, endemic in several parts of India. Most melioidosis-induced infected aneurysms are located in the abdominal or thoracic aorta. CASE PRESENTATION: We reported two unusual cases of melioidosis resulting in pseudoaneurysm of the descending thoracic aorta. In both cases, blood cultures yielded B. pseudomallei. The first patient was managed with resection of aneurysm and reconstruction with Dacron graft followed by medical treatment and was discharged uneventfully. The second patient died within one week of admission before the infecting etiological agent was identified and aneurysmal repair was planned. CONCLUSIONS: A high clinical index of suspicion, especially in areas of endemicity is essential for timely management of intracavitary infected pseudoaneurysms caused by B. pseudomallei and use of rapid microbiological techniques, such as bact/alert 3D system, which enables rapid and early recovery of the etiological agent.

Extra-intestinal salmonellosis in a tertiary care center in South India.

INTRODUCTION: The present study is a retrospective analysis of a total of 36 cases of bacteriologically proven extra-intestinal salmonellosis, managed at Nizam's Institute of Medical Sciences, between 1987 and 2012 (25 years). The extra-intestinal sites involved were the skin, cerebrum, spleen, ovary, synovium, and the skeletal muscle. METHODOLOGY: The extra-intestinal specimens were first processed using standard methods. Colonies suspected as Salmonella were identified by standard laboratory methods, initially by manual biochemical reactions and later by the API system (bioMerieux, Marcy l'Etoile- France) and the Vitek-2 system (bioMerieux). All the Salmonella isolates were sent to Central Research Institute, Kasauli, for serotyping. RESULTS: The predominant serotype isolated was Salmonella Typhi (S. Typhi) in 27 (75%) patients, followed by Salmonella Senftenberg (S. Senftenberg) in 5 (14%), Salmonella Paratyphi A (S. Paratyphi A) in 3 (8%), and Salmonella Typhimurium (S. Typhimurium) in 1 (3%). There was an increasing resistance to ampicillin, chloramphenicol, cephalosporins (third generation), and quinolones over the 25 years. CONCLUSIONS: The diagnosis of extra-intestinal salmonellosis requires a high degree of clinical suspicion and should be included in the differential diagnosis in patients with deep-seated abscesses.