Pattern of Bacterial Infections in Indian Bone Marrow Transplant Patients - Experience from Chennai India

Introduction: Bone marrow transplant, both Autograft and Allograft produces profound immune-suppression and breach of mucosal surfaces leading to many opportunistic infections. There is a difference between infection pattern in countries like India compared to western countries. The western literature is more bothered about reactivation of viral and fungal infections, whereas Indian bone marrow transplant physicians are worried about losing patient to refractory gram negative sepsis. In this study, we have tried to decode the pattern of bacterial infections in Indian transplant patients and tried to suggest an antibiotic stewardship for the same. Materials and methods: This retrospective study included all bone marrow transplants with Febrile neutropenia done at our hospital from September 2014 to July 2021. A total of 440 patients were included and their pattern of bacterial infections with culture sensitivity and response to antibiotics were noted. Results: 36% of patients we included in the study were aged between 40 to 60 years and the age range was from 2 years to 72 years. 59% were autograft and among Allograft 36% were haplo-identical bone marrow transplant. Nearly half the patients presented with fever above 99.5 F and tachycardia as the presenting sign. The WBC count during first episode febrile neutropenia was less than 100cells/cumm in around 25% patients. Empirical antibiotics post culture samples were initiated within 10 min in 95% of patients. Cefoperazone Sulbactum and Amikacin were started empirically as first line in all. Culture positivity rate was 22.7% of which 60% were multi-drug resistant gram negative bacilli which were sensitive only to Colistin / Fosfomycin / Tigecycline. This 60% MDR GNB is very high which may be partially due to MDR bugs in normal intestinal flora of patients from this part of the world. The common Gram-negative bacteria are Pseudomonas, Escherichia coli and Klebsiella. This made us to change antibiotic stewardship policy to Colistin / Fosfomycin / Ceftazidime avibactum very early in course in case of second fever / Hypotension or tachycardia. Our transplant related mortality is around 3% in Allograft due to sepsis and 0% in autograft. The rate of gram positive bacteremia is only 2% and this makes us think of avoiding drugs like Teicoplanin / Glycopeptides in first line empirical therapy. Conclusion: This seven year study had shown 22.7% culture positivity rate in febrile neutropenia transplant patients of which 60% are multi-drug resistant bacteria which is highly contrary to western literature. The rate of gram positive culture growth is only 2% which is lower than western literature. This study implies the importance of region and center specific antibiotic policy for febrile neutropenia and a generalized policy may not work always. Reference:- 1. Ghafur A, Devarajan V, Raj R, Easow J, Raja T. Spectrum of bacteremia in posthematopoietic stem cell transplant patients from an Indian center. Indian J Cancer 2016;53:590-1 2. Krüger W,et al. Early infections in patients undergoing bone marrow or blood stem cell transplantation--a 7 year single centre investigation of 409 cases. Bone Marrow Transplant. 1999 Mar;23(6):589-97. doi: 10.1038/sj.bmt.1701614. PMID: 10217190. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

80. The Utility of Cultures for Isolated Fevers in Patients with Influenza or COVID-19 Receiving Extracorporeal Membrane Oxygenation

Background Critically ill patients receiving extracorporeal membrane oxygenation (ECMO) are at elevated risk for nosocomial infection. Physiological responses to infection on ECMO are difficult to interpret as many clinical characteristics are controlled by the circuit including temperature. This study aimed to determine the culture positivity rates in patients receiving ECMO with influenza or COVID-19. Methods A single center retrospective study was performed on all patients who received ECMO support at a single institution between December 2014 and December 2020 with influenza or COVID-19. All cultures ordered were reviewed for indication. Patients with fever without specific clinical syndrome or signs of decompensation, such as increasing vasopressor requirement were included. Infections and contaminants were defined by treatment team. Results A total of 45 patients received ECMO with an admission diagnosis of influenza or COVID-19 during the study period. This cohort had a median age of 44 (interquartile range (IQR): 36-53) and was predominantly male (84%). The median time on ECMO was 360 hours (IQR: 183-666). 43/137 (31%) of infectious workups were ordered for isolated fever. The most common workup ordered for fever was combination blood cultures (BC) and urine cultures (UC) (13, 30%), followed by combination BC, UC, and respiratory cultures (RC) (11, 26%). Four (9%) infections were identified (3 blood stream, 1 respiratory) and five (12%) cultures grew contaminants (1 blood, 1 respiratory, 2 urine). Culture positivity rate was greatest for BC (3/35, 9%) followed by RC (1/19, 5%), and lowest for UC (0/26, 0%). Conclusion Although cultures are commonly ordered for isolated fever in patients with influenza and COVID-19 receiving ECMO, culture positivity rate is low. In particular, no urinary tract infections were identified and the screening for urinary tract infection in patients receiving ECMO with isolated fever is not beneficial. Further work identifying signs and symptoms associated with infection is needed to improve diagnostic stewardship in this population that is high risk for nosocomial infections. Disclosures All Authors: No reported disclosures

Blood Culture Evaluation for Carbapenem Exposure in Pyogenic Liver Abscess: A Two-Center Retrospective Study

Background: High antibiotic consumption in pyogenic liver abscess (PLA) is unnecessary. Using the databases of two centers, we retrospectively evaluated the effects of blood culture on the exposure to carbapenems in patients with PLA.Methods: All patients diagnosed with PLA at two comprehensive tertiary care centers from 2014 to 2020 were assessed. Demographics and clinical data were analyzed, and multiple regression analysis was performed to investigate the association between blood culture and exposure to carbapenems after controlling for potential confounders.Results: Blood culture results were available in 110 (46.0%) patients, of whom 44 (40.0%) patients were tested positive on bacterial culture. The blood culture positivity rate was significantly higher in the sepsis subgroup than in the non-sepsis subgroup (58.1% vs. 32.9%, P = 0.015). The number of patients receiving carbapenems in the blood culture cohort was significantly lower than that in the other cohort (19.1% vs. 31.8%, P = 0.026). Multivariate analysis showed that patients in the blood culture group were less likely to be treated with carbapenems for >5 days than those in the unavailable blood culture group (adjusted OR = 0.33, 95% CI: 0.16–0.68, P=0.003), especially those in the sepsis subgroup (adjusted OR = 0.17, 95% CI: 0.05–0.53, P = 0.002). Conclusion: Blood culture might be associated with less carbapenem exposure, particularly in PLA complicated with sepsis. More attention should be paid to early blood cultures in the emergency setting.

Blood culture positivity rate for Trypanosoma cruzi in patients with chronic Chagas disease differs among different clinical forms

Background The purpose of this research was to compare the clinical and epidemiological characteristics of patients with chronic Chagas disease with and without positive blood cultures for Trypanosoma cruzi. Methods This was a retrospective longitudinal study that included 139 patients with chronic Chagas disease who underwent blood culture for T. cruzi. Blood cultures were performed using Novy–MacNeal–Nicolle medium enriched with Schneider's medium. Multivariate Cox proportional hazards regression analysis adjusting for age and sex was performed to identify if positive blood culture for T. cruzi was associated with all-cause mortality. Results The blood culture positivity rate was 30.9%. Most patients were born in the Northeast and Southeast regions of Brazil. Patients with positive blood cultures were older (52±13 vs 45±13 y; p=0.0009) and more frequently women (72.1% vs. 53.1%; p=0.03) than patients with negative blood cultures. The frequency of patients with cardiac or cardiodigestive forms was higher among patients with positive vs negative blood cultures (74.4% vs 54.1%; p=0.02). A total of 28 patients died during a mean follow-up time of 6.6±4.1 y. A positive blood culture was associated with all-cause mortality (hazard ratio 2.26 [95% confidence interval 1.02 to 5.01], p=0.045). Conclusions We found a higher proportion of patients with Chagas heart disease among patients with T. cruzi–positive blood cultures. A positive blood culture was associated with an increased risk of all-cause mortality. Therefore T. cruzi persistence may influence Chagas disease pathogenesis and prognosis.

Bacterial pneumonia coinfection and antimicrobial therapy duration in SARS-CoV-2 (COVID-19) infection

Background Bacterial respiratory coinfection in the setting of SARS-CoV-2 infection remains poorly described. A description of coinfection and antimicrobial usage is needed to guide ongoing antimicrobial stewardship. Objectives To assess the rate of empirical antimicrobial treatment in COVID-19 cases, assess the rate and methods of microbiological sampling, assess the rate of bacterial respiratory coinfections and evaluate the factors associated with antimicrobial therapy in this cohort. Methods Inpatients with positive SARS-CoV-2 PCR were recruited. Antibiotic prescription, choice and duration were recorded. Taking of microbiological samples (sputum culture, blood culture, urinary antigens) and culture positivity rate was also recorded. Linear regression was performed to determine factors associated with prolonged antimicrobial administration. Results A total of 117 patients were recruited; 84 (72%) were prescribed antimicrobial therapy for lower respiratory tract infections. Respiratory pathogens were identified in seven (6%) patients. The median duration of antimicrobial therapy was 7 days. C-reactive protein level, oxygen requirement and positive cultures were associated with prolonged duration of therapy. Conclusions The rate of bacterial coinfection in SARS-CoV-2 is low. Despite this, prolonged courses of antimicrobial therapy were prescribed in our cohort. We recommend active antimicrobial stewardship in COVID-19 cases to ensure appropriate antimicrobial prescribing.

Assessment of conjunctival flora in eyes with lacrimal passage obstruction before and after successful dacryoendoscopic recanalisation

BackgroundTo investigate conjunctival bacterial flora in eyes with lacrimal passage obstruction before and after dacryoendoscopic recanalisation with lacrimal tube intubation.MethodsOne-hundred fifty eyes with lacrimal passage obstruction that were successfully treated by dacryoendoscopic recanalisation were enrolled. Conjunctival sampling was done for each eye before and 4 months after surgery. The lower fornix was rubbed by a sterile cotton swab, and the collected samples were cultured with several agar plates. Colonies were differentiated and enumerated by standard bacteriological laboratory techniques.ResultsPositive bacterial growth was detected in 42.0% of all the samples before surgery, and the positivity rate significantly decreased to 26.0% after surgery (p=0.0051). The number of strains detected also decreased from 20 before surgery to 9 after surgery, especially pathogenic microorganisms decreased. In addition, drug-resistant bacteria such as penicillin-resistant Streptococcus pneumoniae and methicillin-resistant Staphylococcus aureus were detected in nine eyes before surgery but were detected only in one eye after surgery. Coagulase-negative Staphylococci and Corynebacterium spp., which are common in normal conjunctival flora, accounted for 46.5% of all the isolates before surgery and 80.9% after surgery, showing a significant increase in the rate after surgery (p<0.0001).ConclusionsThis study showed that physiological recanalisation of lacrimal passage after dacryoendoscopic surgery significantly decreased the culture positivity rate of conjunctival sac and the number of microorganism strains detected. It also decreased the number of potentially pathogenic and drug-resistant bacteria and increased the percentages of indigenous bacteria, causing the normalisation of conjunctival flora.

Sensitivity Pattern of Gram Negative Bacteria Contaminating Traumatic Wounds: A Retrospective Study in a Tertiary Care Hospital of Kathamandu Valley

Introduction: Gram negative bacteria are commonly involved in wound infections and are significantly associated with morbidity and mortality because of increasing resistance to commonly used antibacterial agents. This study aims to evaluate the pattern of antibacterial sensitivity of the gram negative bacteria from wound swabs of accidental trauma cases. Methods: This retrospective study was done by collecting all the culture positive reports for wound swabs of accidental wounds from the microbiology laboratory and analyzing the reports showing growth of gram negative bacteria for frequency of sensitivity to commonly used antibacterial agents. Results: Culture positivity rate was 21.95% with growth of gram negative bacteria in 79.7% of cases. The most commonly isolated organism was Escherichia coli being 41.3% among gram negative isolates. Highly resistant bacteria were E. coli, Klebsiella pneumoniae and Acinetobacter spp. Conclusions: As there is low culture positivity rate for wound swabs obtained before washing the wounds inflicted by accidental trauma, prolonged routine use of prophylactic antibiotic is not justified. Thoroughly washing the wound is very likely to decrease the rate of wound infection further and reduces the need of antibacterial agents. Culture and sensitivity test should guide the treatment when wound is infected because highly resistant gram negative organism may be involved in such cases.

MICROORGANISMS COLONIZING THE CADAVERS: THE NEED OF INFECTION CONTROL PROTOCOLS DURING DISSECTION

Introduction: Microorganisms can colonize the surfaces of cadavers and may pose health hazards to the students and the staff handling them. The objective of the study was to study the spectrum of bacteria and fungi colonizing the surfaces of cadavers and to determine the need to follow infection control protocols during their handling. Materials and methods: A total of 100 swabs were collected from superficial and deep surfaces of the cadavers and its surroundings. The swabs were cultured on blood agar and Mac Conkey’s agar plates for isolation of bacterial species and Sabourauds Dextrose Agar (SDA) slants for isolation of fungal species. Identification of the bacterial and fungal isolates was done using standard bacteriological and mycological methods respectively. Results: Overall culture positivity rate was 78%. There was predominance of isolation of bacterial species (50%). Escherichia coli and Coagulase negative Staphylococci [CoNS] (23.07 % each) were the predominant bacteria isolated and Aspergillus species (37.50%) was the predominant fungus isolated from human cadavers. Conclusions: Various bacteria and fungi colonized the surface of cadavers. Therefore, the study emphasizes the need for practicing “Standard infection control protocols” in the dissection hall while handling the cadavers.

Hourly Effect of Pretreatment With IV Antibiotics on Blood Culture Positivity Rate in Emergency Department Patients

Although it is intuitive that antibiotics administered before obtaining a blood culture would reduce the likelihood of obtaining a positive culture, it is not clear exactly how rapidly and to what extent blood becomes sterile after administration of intravenous (IV) antibiotics. Using a large data set of patients admitted from the UFHealth Shands Adult Emergency Department (ED) between 2012 and 2016 (n = 25 686), we had the opportunity to more closely examine the effect of starting IV antibiotics before vs after obtaining blood cultures. We present data on the effect of pretreatment with IV antibiotics for both septic and nonseptic ED patients on the blood culture positivity rate on an hour-by-hour basis, as well as the effects on distribution of species recovered and the impact of antibiotic resistance in empiric treatment with antibiotics.