Colistin resistance in carbapenem non-susceptible Acinetobacter baumanii in a tertiary care hospital in India: clinical characteristics, antibiotic susceptibility and molecular characterization.

INTRODUCTION: Acinetobacter baumanii (AB) is a bacterium of concern in the hospital setup due to its ability to thrive in unfavorable conditions and the rapid emergence of antibiotic resistance. Carbapenem resistance in this organism is disheartening, further clouded by the emergence of colistin resistance. AIM: The present prospective study aims to note the epidemiology, molecular profile, and clinical outcome of patients with colistin resistance AB infections in a multispecialty tertiary care setup in Odisha, Eastern India. METHODS: All AB strains received from March 2021 to February 2022, identified by Vitek2 (Biomerieux) and confirmed by oxa-51 genes, were included. Carbapenem and colistin resistance were identified as per CLSI guidelines. Known mutations for blaOXA-23-like, blaIMP, blaVIM, blaKP, lpxA, lpxC, pmrA, pmrB, and plasmid mediated mcr (mcr1-5) were screened by conventional PCR techniques. The clinical outcome was noted retrospectively from case sheets. Data was entered in MS Excel and tabulated using SPSS software. RESULTS: In the study period, 350 AB were obtained, of which 317(90.5%) were carbapenem resistant (CRAB). Among the CRAB isolates, 19 (5.9%) were colistin resistant (ABCoR). The most valuable antibiotics in the study were tigecycline (65.4% in ABCoI; 31.6% in ABCoR) and minocycline (44.3% in CI; 36.8% in CR). There was a significant difference in mortality among ABCoI and ABCoR infections. bla OXA was the predominant carbapenem resistance genotype, while pmrA was the predominant colistin resistant genotype. There were no plasmid mediated mcr genes detected in the present study.

Impact of cartridge-based nucleic acid amplification test (CBNAAT) introduction on the detection of pulmonary and extra-pulmonary tuberculosis in Bhubaneswar, Odisha.

Background: Compared to conventional microscopy, the cartridge-based nucleic acid amplification test (CBNAAT, Xpert MTB/RIF, Cepheid, USA) has the dual advantage of higher sensitivity to detect Mycobacterium tuberculosis (M. tb), and the ability to detect rifampicin resistance. Aim: To evaluate the impact of the CBNAAT on the detection of pulmonary and extra-pulmonary tuberculosis from private and public healthcare facilities in Bhubaneswar, Odisha. Materials and Methods: The study included specimens received between June 2015 to February 2017 from public and private health sectors for tuberculosis diagnosis at a national reference laboratory for tuberculosis in Bhubaneswar, where the CBNAAT was initiated in February 2016. We retrospectively collected the patients' socio-demographic characteristics from their test request form, CBNAAT results from the CBNAAT register and PMDT culture and drug susceptibility testing (DST) register and validated the data by comparing the patient details and test results from the CBNAAT software. Results: From June 2015 to January 2016, 106 samples were received from Bhubaneswar at the reference laboratory, of which there were zero referrals from the private sector and zero referrals of extra-pulmonary tuberculosis (TB) samples. After initiation of the CBNAAT, from February 2016 to February 2017, 1262 specimens were received, of which 55.2% (696/1262), 17.8% (225/1262), 17.2% (217/1262), and 9.8% (124/1262) were from government hospitals and medical colleges, private hospitals, private practitioners, and district TB centers, respectively. Conclusion: The availability of TB diagnostics at public sector facilities to patients from private sectors and the rollout of the CBNAAT increased the referral of patients from private health facilities and the referral of paucibacillary non-sputum samples.

Evaluation of different methods for in vitro susceptibility testing of colistin in carbapenem resistant Gram-negative bacilli.

Introduction: The increasing antibiotic resistance like the advent of carbapenem resistant Enterobactarales (CRE), Carbapenem Resistant Acinetobacter baumanii (CRAB), and Carbapenem Resistant Pseudomonas aeruginosa (CRPA) has led to to the use of toxic and older drugs like colistin for these organisms. But worldwide there is an increase in resistance even to colistin mediated both by chromosomes and plasmids. This necessitates accurate detection of resistance. This is impeded by the unavailability of a user-friendly phenotypic methods for use in routine clinical microbiology practice. The present study attempts to evaluate two different methods - colistin broth disc elution and MIC detection by Vitek two in comparison to CLSI approved broth microdilution (BMD) for colistin for Enterobactarales, Pseudomonas aeruginosa , and Acinetobacter baumanii clinical isolates. Methods: Colistin susceptibility of 6013 carbapenem resistant isolates was determined by BMD, Colistin Broth Disc Elution (CBDE), and Vitek two methods and was interpreted as per CLSI guidelines. The MIC results of CBDE, Vitek two were compared with that of BMD and essential agreement (EA), categorical agreement (CA), sensitivity, specificity, very major error (VME), major error (ME) and Cohen's kappa (CK) was calculated. The presence of any plasmid-mediated colistin resistance (mcr-1, 2, 3, 4 and 5) was evaluated in all colistin-resistant isolates by conventional polymerase chain reaction. Results: Colistin resistance was found in 778 (12.9 %) strains among the carbapenem resistant isolates. Klebsiella pneumoniae had the highest (18.9 %) colistin resistance by the BMD method. MIC of Vitek two had sensitivity ranging from 78.2-84.8% and specificity of >92 %. There were 171 VMEs and 323 MEs by Vitek two method, much more than CLSI acceptable range. The highest percentage of errors was committed for Acinetobacter baumanii (27.8 % of VME and 7.9 % ME). On the other hand, the CBDE method performed well with EA, CA, VME and ME within acceptable range for all the organisms. The sensitivity of the CBDE method compared to gold standard BMD varied from 97.5-98.8 % for different strains with a specificity of more than 97.6 %. None of the isolated colistin resistant organisms harboured mcr plasmids. Conclusion: As BMD has many technical complexities, CBDE is the best viable alternative available for countries like India. A sensitive MIC reported by Vitek two needs to be carefully considered due high propensity for VMEs particularly for Klebsiella spp.

An overview of colistin resistance: A breach in last line defense.

Rising prevalence of antibiotic resistance and the unavailability of newer drugs to tackle this menace is one of the major hindrances to the goal of health and well-being set up by the General Assembly of the United Nations. The genes responsible for this resistance are often disseminated from hospitals to different environmental sources. In 2015, for the first time, resistance to Colistin was detected caused by chromosomal genetic mutations. Later, plasmid-mediated colistin resistance (MCR-1 to MCR-10) was detected, first from China and then from various other countries. As per Clinical and Laboratory Standards Institute (CLSI), commonly available diffusion techniques cannot detect colistin resistance appropriately. Even commercial susceptibility systems fail in this regard. Keeping in mind the importance of surveillance of colistin-resistant bugs, we present an update on the prevalence, mechanism of resistance, and detection.

Spinal fungal abscess mimicking as potts spine.

Spinal epidural abscess (SEA) is a rarest form of spinal infections and is characterized by the presence of pus in the space between the dura mater, and the osseoligamentous confines of the vertebral canal. This can cause spinal injury due to direct compression or local ischemia. The major etiology of SEA is bacterial and tuberculous in endemic regions. The incidence of fungal spinal abscess is relatively low and <5% of SEA is attributable to fungi. We, here, report a case of 77-year-old known patient of chronic renal disease on hemodialysis that presented with low-back pain for 15 days and was subsequently diagnosed with SEA by magnetic resonance imaging, and causative organism was identified as Candida by culture. The abscess was surgically drained after laminectomy. The patient improved with surgery and antifungal treatment.

A case of spinal tuberculosis presenting with cauda equina syndrome.

Tuberculosis (TB) of the central nervous system accounts for only 1% of all cases of TB but 50% of these occur in the spine. Common clinical manifestations of spinal TB include fever, weight loss, back pain, lower limb weakness (either upper or lower motor neuron), and skeletal deformities such as kyphosis or gibbus. Infective pathology caused by Mycobacterium tuberculosis with epidural collection can present as acute cauda equina syndrome. Here, we describe a 28-year-old female patient who presented with low back pain and ascending weakness of both lower limbs (Medical Research Council grade 4/5 with absent ankle reflex) for 2 months with sudden-onset loss of bladder and bowel control for 1 day without any localized spinal tenderness, swelling, or discharging sinus in the back. Magnetic resonance imaging (MRI) spine was suggestive of an intraosseous collection with spondylodiscitis at the L4 level vertebral level. MRI can help identify the involvement of the vertebral bodies on either side of the disk, disk destruction, cold abscess, vertebral collapse, and the presence of vertebral column deformities making it a sensitive tool for the detection of spinal TB. Antituberculous treatment remains the cornerstone of treatment. Surgery is required in selected cases, for example, large abscess formation, severe kyphosis, an evolving neurological deficit, or lack of response to medical treatment. A combined intervention of laminectomy with drainage of the collection with antitubercular therapy after microbiological evidence helped in the resolution of the patient's condition. Early diagnosis and appropriate treatment generally result in a good prognosis.

A rare case of calvarial tuberculosis in post-COVID-19 scenario.

Isolated calvarial involvement with tuberculosis (TB) is a very rare entity, with the incidence of only 0.01% of all patients with mycobacterial infections. The factors attributable could be malnutrition, poor socioeconomic conditions, and immunodeficiency syndromes. We hereby present the case of a 35-year-old male who had recently recovered from coronavirus disease 2019 and a diagnosed case of Evan's syndrome with secondary hemophagocytic lymphohistiocytosis who presented with a scalp swelling on the right frontotemporal region. He presented to the emergency department with acute-onset generalized tonic - clonic seizures with high-grade fever. Clinically, the swelling appeared like a cystic swelling of the scalp. On evaluation, there was a collection present below the scalp communicating with the extradural space, involving the underlying skull bone. The patient was operated with drainage of the abscess plus excision of the pathological underlying skull bone. The pus revealed florid amount of acid-fast bacillus on Ziehl-Neelsen staining. The patient was started on four drugs Category 1 antitubercular regimen. The patient responded well to the combined surgical and medical treatment. It should be emphasized that TB can involve any part of the body. It should be kept as differential diagnosis of any chronic inflammatory lesion involving the bony skeleton, especially in endemic countries where combined surgical and medical treatment is usually sufficient to provide a cure.

ABO blood grouping and COVID-19: a hospital-based study in Eastern India.

Background: Blood group has been stated to be one of the risk factors associated with viral diseases like dengue, hepatitis virus, Norwalk virus and even the coronavirus associated with 2003 severe acute respiratory syndrome (SARS) outbreak. In addition, anti-A antibodies in experimental models have been shown to inhibit the interaction between coronavirus and angiotensin converting enzyme (ACE) receptor of the host target cell, the major receptor involved in viral pathogenesis. Thus, several workers propose an association between ABO blood type and coronavirus disease- 2019 (COVID-19) disease in many previous studies. The present study was undertaken in the Eastern part of India in line with these authors to study the association of ABO blood group of patients with COVID susceptibility and severity. Methods: This is a retrospective study over a period of 6 months from June 2020 to November 2020 where patients who underwent quantitative real-time polymerase chain reaction (qRT-PCR) test for SARS-COV2 and having a recorded patient blood group type were considered. The qRT-PCR positive admitted cases were considered as cases, and qRT-PCR negative cases were considered as controls. Data were entered in Microsoft Excel format and analyzed by statistical method to obtain association. Results: Consecutively obtained 5000 qRT-PCR positive patients (cases) and 11,700 (controls) were included in the present study. The mean age of cases was higher (54.24 vs. 34. 67) than the controls. Among the cases, the highest number (2379; 47.6%) of samples belonged to A blood group followed by B (1278; 25.6%) while among the control group O blood group had the highest prevalence (4215; 36%). Blood group A had a higher odd of testing positive (Odds ratio-2.552; CI 2.381-2.734; p < 0.0001) than all other blood groups. A blood group is also associated with higher risk of ICU admission (Odds ratio- 1.699; 95% CI 1.515-1.905) and 65.3% of this group is also associated with high viral load which gives an indication of higher disease severity. Conclusion: Blood group A is associated with an increased susceptibility to COVID 19 infection than other blood groups. Cases of this blood group are also associated with more critical care needs and a higher viral load on testing.

Fasciola hepatica association with gallbladder malignancy: A rare case report.

Fasciolopsis is one of the rarest parasitic infestations in our locality. The usual definitive host is the sheep; humans are accidental hosts in the life cycle of a liver fluke - Fasciola. In the chronic phage of Fasciolopsis, the patient presents with cholestasis and cholangitis. Yet, there is no proof of association of this parasite with carcinoma of the gallbladder. We here present such a case of Fasciolopsis in association with Stage IV gallbladder malignancy. Fasciola worms were extracted on endoscopic retrograde cholangiopancreatography done as a palliative measure for associated obstructive jaundice. The chronic phase of this zoonotic infection can be easily misdiagnosed as any other cause of obstructive jaundice if not properly investigated. The importance of repeated stool examination for parasitic ova and cysts should never be understated as it may help in early diagnosis of such treatable conditions as well as preventing the complications.

Detection and genetic characterization of extended-spectrum beta-lactamases producers in a tertiary care hospital.

BACKGROUND: Extended-spectrum beta-lactamase (ESBL)-producing organisms inactivate extended beta-lactam antibiotics and monobactams and also exhibit coresistance to many other classes of antibiotics. The present study was carried out to assess the prevalence of the ESBLs and to determine the most prevalent genotype in our hospital. MATERIALS AND METHODS: All clinically significant Gram-negative isolates were identified, and their antimicrobial susceptibility testing was done by Kirby-Bauers' disc diffusion method. ESBL detection was confirmed by minimal inhibitory concentration method using agar dilution technique for those who screened positive by ceftazidime (30 µg) disc. Further, the established ESBL-positive isolates were subjected to genotyping for bla TEM, bla CTX-M, and bla SHV genes by using conventional polymerase chain reaction. RESULTS: Escherichia coli was the most common (28.84%) Gram-negative bacillus followed by Klebsiella pneumoniae (18.07%), while Pseudomonas spp. (9.61%) was the most commonly identified nonfermenter. ESBL production was detected in 160 (30.8%) isolates. Klebsiella oxytoca (46.7%) followed by E. coli (44%) were the common ESBL producers. Most predominant ESBL gene was bla TEM, found in 122 (76.25%) isolates. Combinations of two genes were seen in 109 (68.1%) isolates, the most common (43.12%) combination being blaTEM and blaCTX-M. In this study, 16 (10%) strains had all the three types of genes. Most of the isolated Gram-negative bacilli (GNB) were sensitive to amikacin, imipenem, and colistin. CONCLUSION: In our study, the 30.8% of GNB were ESBL producers. This is the only study that shows that TEM is the most prevalent ESBL genotypes in our area. Of concern is a good number of isolates showing all three patterns of genes (TEM, SHV, and CTX-M). Amikacin, imipenem, and colistin were the most useful antibiotics in our setup.

Urinary tract infection by chromobacterium violaceum.

Chromobacterium violaceum, a facultative anaerobic proteobacterium, is particularly isolated from water and soil in tropical areas and has been implicated in few infections like septicemia, visceral abscesses, skin and soft tissue infections, meningitis and diarrhea. But urinary tract infection caused by it is very rare. Limited awareness about this pathogen and inappropriate antibiotic therapy contribute to a high mortality rate. Here, we describe an unusual case of urinary tract infection by Chromobacterium violaceum in a young immuno-competent male which was managed aggressively with proper antibiotics as per the culture sensitivity report.