Cocci Research Articles

Evaluation of a new protocol for rapid identification of Streptococcus pneumoniae in blood cultures using the modified bile solubility test: Gram staining is still standing.

This study aimed to evaluate a new protocol of the bile solubility test performed directly on the blood from positive blood culture bottles to identify Streptococcus pneumoniae rapidly. Seventy-five positive blood cultures (PBC) showing Gram-positive cocci in pairs or chains on Gram stain, including 32 S. pneumoniae isolates and three reference American Type Culture Collection (ATCC) isolates were included to evaluate the performance of a modified bile solubility test (MBST). One milliliter of blood from the PBC bottle was mixed with 0.5 mL of 10% desoxycholate or a saline solution. Both suspensions were analyzed after 10 min of incubation through a Gram stain to detect solubilization. This technique was compared with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry identification, performed on PBC following extraction or on colonies after short or standard incubation, and the optochin susceptibility test on colonies. The capsular serotypes were determined for all S. pneumoniae, and the Belgian National Reference Center confirmed the identification. All 32 clinical isolates and the ATCC isolate of S. pneumoniae were solubilized on the desoxycholate-treated slides, while the other species tested remained visually unchanged on both, the test and control slides. The MBST test demonstrated a 100% sensitivity and specificity with a mean turnaround time (TAT) of just 39 min, making it 14 h and 56 min faster than the optochin susceptibility test. This rapid variant of the bile solubility test appears to be a reliable method to identify S. pneumoniae directly from positive blood culture bottles, with a TAT of 39 min. It is a cost-effective, easy-to-perform, and time-efficient technique. Negative results should be interpreted cautiously, as they may result from mixed infections with S. pneumoniae and other Gram-positive cocci.

Comprehensive Insights into Cephalosporins: Spectrum, Generations, and Clinical Applications

Abstract: Cephalosporins, a widely utilized class of antibiotics in clinical settings for bacterial infections, are the focus of this critical analysis. This examination aims to provide a comprehensive description, encompassing their range, generational distinctions, and therapeutic applications. Renowned for their versatility against both Gram-positive and Gram-negative bacteria, cephalosporins have evolved over generations, enhancing efficacy and addressing resistance patterns. Each generation possesses unique characteristics crucial for clinical utility. Primarily targeting Gram-positive cocci, first-generation cephalosporins exhibit a broadened spectrum in subsequent generations, encompassing Gram-negative species. Advancements in penetration into tissues and resistance against beta-lactamases contribute to increased effectiveness as generations progress. Clinically, cephalosporins find application across diverse medical disciplines, from intricate hospital environments to community-acquired illnesses. A comprehensive understanding of each generation's distinct features empowers clinicians to tailor treatment regimens, optimizing therapeutic outcomes and mitigating resistance risks. This meticulous examination consolidates the latest available information on cephalosporins, serving as an invaluable resource for medical professionals involved in antibiotic prescription and infection management. A profound understanding of cephalosporin characteristics and generations proves indispensable in navigating the dynamic landscape of bacterial resistance, ultimately enhancing patient care.

A Decade-Long Analysis of Trends in Antimicrobial Resistance in a Neurosurgical Hospital in Kathmandu, Nepal.

Multidrug-resistant (MDR) bacteria cause infections with higher risks of morbidity, mortality, and financial burden. Understanding the antimicrobial resistance patterns of these pathogens is crucial for effective treatment and managing resistance. Therefore, this retrospective study examined the prevalence, causes, and trends in antimicrobial resistance in bacterial infections at a neurosurgical hospital in Nepal. We analyzed the demographics, bacteriological profiles, and antimicrobial susceptibility results in patients who visited Dirghayu Guru Hospital and Research Center, Kathmandu, Nepal, between January 2014 and January 2024, using SPSS, version 17.00. Among 4758 patients, 465 (9.77%) had infections caused by 571 bacteria. Of them, 435 (93.55%) patients had urinary tract infections, 89 (19.14%) had bloodstream infections, and 31 (6.67%) had respiratory tract infections. Klebsiella pneumoniae (n = 172, 30.12%) was the predominant bacteria. Proportions of drug-resistant Enterobacterales and gram-positive cocci among drug-resistant bacteria against tetracyclines were 83.33% and 45.83%, cephalosporins were 78.02% and 40.45%, quinolones were 72.25% and 50.00%, aminoglycosides were 65.14% and 43.53%, carbapenems were 62.96% and 30.00%, penicillins were 54.55% and 57.89%, and penicillin with beta-lactamase inhibitors (PwBLIs) were 40.54% and 42.31%, respectively. Proportions of drug-resistant nonfermenters among drug-resistant bacteria showed 100.00% resistance to these antimicrobials. MDR isolates (n = 118, 20.67%) were 100.00% susceptible to piperacillin-tazobactam and 83.33% to polymyxin B. Over the years, resistance increased for cephalosporins (48.15%-60.53%) but decreased for carbapenems (50.00%-33.33%), penicillins (64.29%-42.31%), PwBLIs (50.00%-12.50%), aminoglycosides (60.00%-49.12%), tetracyclines (100.00%-16.67%), and polymyxins (76.22%-16.67%). One-tenth of hospital-visiting patients had bacterial infections, with three-fourths involving Enterobacterales and one-fifth involving MDR bacteria. In recent years, resistance to cephalosporins has increased, whereas resistance to other beta-lactams, aminoglycosides, and polymyxins has decreased.

Endogenous Endophthalmitis caused by Abiotrophia/Granulicatella

Purpose To describe a case of endogenous endophthalmitis caused by the bacterium Abiotrophia/Granulicatella adiacens, which clinically appeared consistent with fungal endophthalmitis, in a young patient with a history of intravenous (IV) drug use. Observations A 22-year-old male presented with one week of pain and decreased vision in the left eye. He had a history of IV heroin use. Slit lamp and dilated fundus exam revealed significant intraocular inflammation concerning for endogenous endophthalmitis. The initial clinical impression was of fungal endophthalmitis given the appearance of vitreous opacities consistent with fungal balls. However, vitreous sampling revealed Abiotrophia/Granulicatella adiacens, a species of fastidious gram-positive cocci formerly known as nutritionally variant streptococci. Conclusion We describe Abiotrophia/Granulicatella species causing endogenous endophthalmitis in a patient with a history of IV drug use. Abiotrophia/Granulicatella have not been described previously to cause endophthalmitis. This atypical case expands the spectrum of microorganism’s clinicians should consider when diagnosing and treating endogenous endophthalmitis.

Recurrent septic arthritis caused by Gemella morbillorum: a case report and literature review

Gemella morbillorum is a gram-positive coccus that is part of the normal microbiota of the human oral cavity and gastrointestinal tract. It is an opportunistic pathogen that can cause invasive infections, including septic arthritis. Septic arthritis caused by Gemella morbillorum is relatively rare, but when it occurs, it can lead to severe joint damage and other complications if not promptly diagnosed and treated. Here, we report a case of recurrent septic arthritis caused by Gemella morbillorum.

Characterizing Early-Onset Surgical Site Infection after Lower Extremity Bypass Surgery

Surgical site infections (SSI) are the most common complication following lower extremity bypass (LEB) surgery. SSIs contribute to significant patient morbidity and healthcare expenditure, and accurate detection of SSIs remains an important step in reduction efforts. In this study, we aimed to characterize early-onset SSIs among patients undergoing LEB surgery. Institutional medical records were retrospectively queried for all LEB operations performed across three hospitals from 2018-2022. All SSIs within a 90-day postoperative period were included, per CDC definition, and categorized as early- (within seven days of operation), standard- (8-30 days), or delayed-onset (31-90 days). The Southampton grading scale was used to stratify the severity of infection (grade 2, erythema; grade 3, erythema with serous drainage; grade 4; erythema with purulent drainage; or grade 5, severe wound necrosis). Data were analyzed using univariate tests and logistic regression analysis. A total of 517 LEB operations were performed over the five-year study period. Median follow-up period was 18.5 months. Early-, standard-, and delayed-onset SSIs were diagnosed in 2.9% (n=15), 15.1% (n=78), and 4.6% (n=24) of patients, respectively. Compared with standard- and delayed-onset groups, patients with early-onset SSIs were more frequently non-smokers (26.7% vs 3.9% vs 8.3%, p=0.03) and had lower prevalence of comorbidities. Early-onset SSIs most frequently presented as Southampton grade 2 (60.0%) or grade 5 (20.0%) infections; whereas standard- and delayed-onset SSIs were more evenly distributed among grade 2 (30.4%), grade 3 (41.2%), and grade 4 (21.6%) presentations (p=0.002). The most commonly isolated organisms among the early-onset SSI group were Gram-negative rods (20.0%). In comparison, polymicrobial infections (19.6%) and Gram-positive cocci (14.7%) were most common among standard- and delayed-onset groups (p=0.04). The early-onset SSI group experienced a longer index hospitalization (11 vs 6 vs 8 days, p=0.02) and lower 30-day readmission rates (13.3% vs 59.0% vs 45.8%, p=0.005) compared with standard- and delayed-onset groups. On multivariate analysis, active smoking (hazard ratio [HR] 0.15, 95% confidence interval [CI], 0.02-0.98, p=0.035), former smoking (HR 0.08, 95% CI, 0.01-0.71, p=0.02), coronary artery disease (HR 0.15, 95% CI, 0.03-0.83, p=0.03), and hypertension (HR 0.13, 95% CI, 0.03-0.68, p=0.02) were associated with a lower risk of early-onset infection, when compared with patients suffering standard- and delayed-onset SSIs. Early-onset SSIs after LEB surgery have a distinct clinical presentation, impact healthier patients, and are associated with more virulent organisms compared with standard- and delayed-onset SSIs.

Biofilm Formation and Plasmid-Mediated Quinolone Resistance Genes at Varying Quinolone Inhibitory Concentrations in Quinolone-Resistant Bacteria Superinfecting COVID-19 Inpatients.

The likelihood of antimicrobial failure in COVID-19 patients with bacterial superinfection arises from both phenotypic (biofilms) and genotypic mechanisms. This cross-sectional study aimed to determine the inhibitory concentrations of quinolones-nalidixic acid, norfloxacin, ciprofloxacin, ofloxacin, and levofloxacin-in biofilm formers (minimum biofilm inhibitory concentration [MBIC]) and nonformers (minimum inhibitory concentration [MIC]) and correlate inhibitory concentrations with plasmid-mediated quinolone resistance (PMQR) genes in quinolone-resistant bacteria isolated from COVID-19 inpatients. Quinolone-resistant bacteria (n = 193), verified through disc diffusion, were tested for quinolone inhibitory concentrations using broth microdilution and biofilm formation using microtiter plate methods. The polymerase chain reaction was used to detect PMQR genes. Study variables were analyzed using SPSS v.17.0, with a significance level set at P <0.05. MIC-to-MBIC median fold increases for ciprofloxacin, ofloxacin, and levofloxacin were 128 (2-8,192), 64 (4-1,024), and 32 (4-512) in gram-positive cocci (GPC, n = 43), respectively, whereas they were 32 (4-8,192), 32 (4-2,048), and 16 (2-1,024) in fermentative gram-negative bacilli (F-GNB, n = 126) and 16 (4-4,096), 64 (2-64), and 16 (8-512) in nonfermentative gram-negative bacilli (NF-GNB, n = 24). In biofilm-forming F-GNB and NF-GNB, qnrB (10/32 versus 3/10), aac(6')-Ib-cr (10/32 versus 4/10), and qnrS (9/32 versus 0/10) genes were detected. A 32-fold median increase in the MIC-to-MBIC of ciprofloxacin was significantly (P <0.05) associated with qnrA in F-GNB and qnrS in NF-GNB. Biofilms formed by F-GNB and NF-GNB were significantly associated with the aac(6')-Ib-cr and qnrS genes, respectively. Nearly one-third of the superinfecting bacteria in COVID-19 patients formed biofilms and had at least one PMQR gene, thus increasing the need for quinolones at higher inhibitory concentrations.

ETIOLOGICAL AND RESISTANCE PROFILE OF BACTERIA ISOLATED FROM PRIMARY BLOOD STREAM INFECTIONS ASSOCIATED WITH PERIPHERALLY INSERTED CENTRAL CATHETER IN NEONATES

Introduction: The Peripherally Inserted Central Catheter (PICC) is a peripherally inserted intravenous device with central venous access characteristics, with bloodstream infection being the main complication associated with the presence of this catheter. The main pathogens involved are: Candida sp., gram-positive cocci of the genus Staphylococcus coagulase-negative and gram-negative bacilli. Objective: To identify the main risk factors for neonates reported with laboratory-confirmed Primary Bloodstream Infection (PBSI) associated with PICC, as well as the etiological profile and resistance of the most prevalent bacteria. Methodology: Descriptive study with a quantitative approach carried out from January/2015 to December/2016 in the ICU of a maternal and child hospital. The sample consisted of reported cases with PICC-associated BSI. Data collection was performed using notification forms, blood culture results and antibiograms attached to the medical records. Data were tabulated and analyzed using descriptive statistics. Results: The main risk factors associated with bloodstream infection were: prematurity, prolonged hospitalization, catheter indwelling time, use of antibiotics and parenteral nutrition. Regarding the microbiological profile, S. epidermidis predominated, with 71% of strains resistant to oxacillin. Conclusion: Care planning by the interdisciplinary team for adequate management of the PICC, as well as monitoring, evaluation and discussion of the rates of PICC-associated infections will enable the adaptation of practices that minimize the rates of hospital infections.

SARCINA VENTRICULI-RELATED GASTRITIS: A RARE CASE OF GASTRIC INFECTION IN A PATIENT WITH DELAYED GASTRIC EMPTYING

Sarcina ventriculi (SV), which is also called Clostridium ventriculi, is a rare, non-motile, aerobic, Gram-positive coccus that breaks down carbohydrates through fermentation. It thrives in acidic environments, making the human stomach a suitable habitat, particularly in conditions associated with gastric stasis. SV belongs to the Clostridiaceae family. Recent studies have implicated Sarcina ventriculi in severe gastrointestinal conditions, including emphysematous gastritis, pyloric stenosis, gastroparesis, gastric outlet obstruction, gastric perforation, and gastric adenocarcinoma. Increased awareness of this organism and further studies are essential to understanding its role in human disease.

BACTERIOLOGICAL PROFILE OF SURGICAL SITE INFECTIONS AND THEIR ANTIBIOGRAM: A STUDY IN A TERTIARY CARE HOSPITAL

Objective: To ascertain the frequency of surgical site infection (SSI) occurrences and the prevalence of aerobic bacterial infections associated with their antibiogram. Methods: For 1 year, a tertiary care hospital affiliated with Government Medical College, Amritsar, served as the site of this cross-sectional study. Pus aspirates were aseptically taken from 86 consecutive individuals suspected of having SSI using a sterile surgical syringe with a needle and sterile cotton surgical swabs. The specimens were cultivated and placed in an incubator at 37°C for 24 h. The individual strains were then identified using traditional techniques. The Kirby–Bauer’s Disc Diffusion Method was employed to conduct antimicrobial susceptibility testing. Results: Among 1021 patients, 86 were clinically suspected of SSI, and 64 were culture-positive. The incidence of SSI was 8.42%. The most common organisms were Klebsiella pneumoniae 34% (17/50) and Escherichia coli 32% (16/50), whereas Staphylococcus aureus 100% (14/14) was the only organism found among Gram-positive cocci. The antimicrobial Profile of Gram-positive isolates showed maximum sensitivity to linezolid (100%), followed by erythromycin (85.7%). The antimicrobial profile of lactose fermenters revealed maximum sensitivity to polymyxin (100%). Antibiogram of Proteus species showed maximum sensitivity to meropenem (100%) and ceftazidime tazobactam (100%). Non-fermenters showed 100% polymyxin and 80% sensitivity to aztreonam. Conclusion: Our study has revealed significant findings. The incidence of SSI was found to vary between 8% and 12% in our tertiary care center. K. pneumoniae 26.5% (17/64) and E. coli 25% (16/64) were the most common organisms isolated. S. aureus 21.2% (14/64) was the only organism found among Gram-positive cocci. SSI below waist surgery was far more 75% (48/64) than above waist surgery of 25% (16/64).

Biofilm formation and antibiogram profile of bacteria from infected wounds in a general hospital in southern Ethiopia

Biofilm-producing bacteria associated with wound infections exhibit exceptional drug resistance, leading to an escalation in morbidity, worse clinical outcomes (including delay in the healing process), and an increase in health care cost, burdening the whole system. This study is an attempt to estimate the prevalence and the relationship between the biofilm-forming capacity and multi-drug resistance of wound bacterial isolates. The findings intended to help clinicians, healthcare providers and program planners and to formulate an evidence-based decision-making process, especially in resource-limited healthcare settings. This study was done to assess the prevalence of bacterial infections in wounds and the antibiogram and biofilm-forming capacity of those bacteria in patients with clinical signs and symptoms, attending a General Hospital in southern Ethiopia. A cross-sectional study was performed in Arba Minch General Hospital from June to November 2021. The study participants comprised 201 patients with clinically infected wounds. Demographic and clinical data were gathered via a structured questionnaire. Specimens from wounds were taken from each participant and inoculated onto a series of culture media, namely MacConkey agar, mannitol salt agar, and blood agar, and different species were identified using a number of biochemical tests. Antimicrobial susceptibility tests were performed by means of the Kirby-Bauer disc diffusion technique following the guidelines of the Clinical and Laboratory Standards Institute. A micro-titer plate method was employed to detect the extent of biofilm formation. Bivariable and multivariable logistic regression models were applied to analyse the association between dependent and independent variables, and P values ≤ 0.05 were considered as statistically significant. Data analyses were done with Statistical Package for the Social Sciences version 25. Out of the 201 clinically infected wounds, 165 were found culture-positive with an overall prevalence of 82% (95% CI: 75.9–86.9). In total, 188 bacteria were recovered; 53.1% of them were Gram-positive cocci. The often-isolated bacterial species were Staphylococcus aureus, 38.3% (n = 72), and Pseudomonas aeruginosa, 16.4% (n = 31). The Gram-positive isolates showed considerable resistance against penicillin, 70%, and somewhat strong resistance against tetracycline, 57.7%. Gram-negative isolates showed severe resistance to ampicillin, 80.68%. The overall multi-drug resistance (MDR) among isolates was 48.4%. Extended beta-lactamase (ESBL)-producing Gram-negatives and methicillin-resistant Staphylococcus aureus (MRSA) accounted for 49 and 41.67%, respectively; 62.2% of the isolates were biofilm formers and were correlated statistically with MDR, ESBL producers, and MRSA (P < 0.005). The extent of biofilm formation and the prevalence of MDR bacteria associated with infected wounds hint at a public health threat that needs immediate attention. Thus, a more balanced and comprehensive wound management approach and antimicrobial stewardship program are essential in the study setting.

The effect of medical face masks on inhalation risk of bacterial bioaerosols in hospital waste decontamination station

There is insufficient research on bioaerosols in hospital waste decontamination stations. This study aimed to investigate the effect of three-layer and N95 masks in reducing the inhalation risk of bacterial bioaerosols in a waste decontamination station at a teaching hospital. Active sampling was conducted on five different days at three locations: the yard, resting room, and autoclave room in three different modes: without a mask, with a three-layer mask, and with an N95 mask. Bacterial bioaerosols passing through the masks were identified using biochemical tests and polymerase chain reaction (PCR). The median concentration and interquartile range (IQR) of bacterial bioaerosols was 217.093 (230.174) colony-forming units per cubic meter (CFU/m3), which is higher than the recommended amount by Pan American Health Organization (PAHO). The resting room had high contamination levels, with a median (IQR) of 321.9 (793.529) CFU/m3 of bacterial bioaerosols. The maximum concentration of bioaerosols was also recorded in the same room (2443.282 CFU/m3). The concentration of bacterial bioaerosols differed significantly between using a three-layer or N95 mask and not using a mask (p-value < 0.001). The non-carcinogenic risk level was acceptable in all cases, except in the resting room without a mask (Hazard Quotient (HQ) = 2.07). The predominant bacteria were Gram-positive cocci (33.98%). Micrococci (three-layer mask = 51.28%, N95 mask = 50%) and Coagulase-negative Staphylococci (three-layer mask = 30.77%, N95 mask = 31.82%) were the most abundant bioaerosols passing through the masks. The results obtained are useful for managerial decisions in hospital waste decontamination stations to reduce exposure to bioaerosols and develop useful guidelines.

Distribution of Pathogenic Bacteria and Drug Resistance in ICU of a Newly Built Hospital.

This study investigated the distribution and resistance patterns of pathogens in the intensive care unit of a newly established hospital in Guizhou Province to promote the rational use of antibiotics to reduce multidrug resistance. A retrospective analysis was conducted on the distribution of pathogens and changes in drug resistance in the ICU of a newly built hospital in Guizhou Province from March 2019 to December 2023. WHONET 5.6 was used to analyze the results. A total of 2444 culture samples were received, predominantly sputum (34.66%) and blood (23.36%) samples, with a steady annual increase in specimen types. A total of 572 pathogenic strains were isolated, predominantly from respiratory specimens (54.02%), including 345 Gram-negative bacteria (60.31%), 135 Gram-positive cocci (23.60%), and 92 fungi (16.08%). The most frequent pathogens included Acinetobacter baumannii (30.77%), Candida albicans (11.71%), and Klebsiella pneumoniae (9.97%). Drug sensitivity tests indicated a fluctuating resistance rate of Acinetobacter baumannii over the past five years. Staphylococcus aureus displayed strong in vitro activity against vancomycin, tigecycline, and linezolid, with no resistant strains identified. The detection rates of carbapenem-resistant Acinetobacter baumannii (CR-AB), carbapenem-resistant Pseudomonas aeruginosa (CR-PA), methicillin-resistant Staphylococcus aureus (MRSA), and strains producing extended-spectrum beta-lactamases (ESBL) were 86.78%, 26.79%, 32.45%, 70.27%, and 23.54%, respectively. Compared with other countries in the world, China has increased its data on the prevalence of MDR pathogens and antibiotic resistance.The high resistance rate of Acinetobacter baumannii in the ICU underscores the need for effective infection control measures. Enhanced monitoring of CR-AB, ESBL-producing bacteria, and MRSA is essential, along with improved management of antibacterial drugs and the pursuit of new therapeutic options.

Accuracy and reliability of direct disc diffusion antibiotic susceptibility test from flagged-positive of blood culture.

Antibiotic susceptibility tests (AST) done on blood cultures are critical for the treatment of patients suspected to be suffering from bloodstream infection. The objective of this study was to evaluate the accuracy and reliability of disc diffusion AST conducted directly (direct AST) from flagged-positive blood cultures, especially for Gram-positive cocci bacteria. This study compared direct AST with conventional AST (broth micro-dilution). The antibiotics studied were piperacillin/tazobactam, gentamicin, ceftazidime, erythromycin, and penicillin. Accuracy was determined by calculating very major, major, and minor errors. The reliability was determined by categorical agreement and weighted Kappa index. Gram-positive cocci bacteria were grown in pairs of blood culture bottles and tested with the two methods of AST. No very major errors were detected among the five types of antibiotics. Major errors of 2.56% and minor errors of 4.93% were found when testing gentamicin. The major and minor errors when testing erythromycin were 2.85% and 1.23%, respectively. Perfect agreements (categorical agreement: 100%; weighted Kappa index: 1) of the two AST methods were observed with piperacillin/tazobactam, ceftazidime, and penicillin. Almost perfect agreement was found with gentamicin and erythromycin. Categorical agreement results when testing antibiotics gentamicin and erythromycin were 93.83% and 97.53%, respectively. In addition, the weighted-Kappa index when testing these two antibiotics were 0.92 and 0.96, respectively. The accuracy and reliability of the direct AST was within acceptable limits.

Cefoxitin and Oxacillin Resistance Conundrums

Recently, mecA-negative Staphylococcus aureus strains with decreased susceptibility to oxacillin and cefoxitin have been sporadically reported worldwide. They are called as borderline oxacillin resistant Staphylococcus aureus (BORSA). Almost, more than 30% of such strains are often misinterpreted and reported as MRSA (methicillin resistant Staphylococcus aureus) due to the hyperproduction of beta-lactamase enzyme and other reasons which results in invitro reduced susceptibility to oxacillin as well as cefoxitin. Similar phenomenon is quite common in other staphylococci, micrococci and macrococci. In order to identify beta-lactamase hyperproducing staphylococci and other gram-positive cocci and to avoid false reporting as methicillin resistant, a one-year prospective study was conducted in Deccan college of medical sciences, Hyderabad, Telangana state, India in 2023. During one year duration, 5630 inpatient (IP) and 823 outpatient (OPD) samples accounting for total 6453 cultures were received in the microbiology laboratory. Out of this,100 cultures of different samples showing pure growth of gram-positive cocci suggestive of staphylococci, micrococci and other Gram-positive cocci were included in the present study and tested against different antibiotics panel as per CLSI guidelines (Clinical and Laboratory Standards Institute.) Inclusion of amoxiclav disc to the antibiotics test panel as per recommendation by the special phenotypic methods for the detection of antibacterial resistance in the manual of clinical microbiology was helpful to detect the beta-lactamase hyperproducers (BHP) and helped to report correct identification of the organisms and curtailed the mismanagement of more than 95% of the patients. Therefore, I do recommend to differentiate borderline from true methicillin resistant strains to streamline the antibiotic therapy and hence further avoidance of selection of the resistant strains.

Epidemiology of Bacteremia in Patients with Hematological Malignancies and Hematopoietic Stem Cell Transplantation and the Impact of Antibiotic Resistance on Mortality: Data from a Multicenter Study in Argentina.

The epidemiology of bacteremia and the antibiotic resistance profile (ARP) of Gram-negative bacilli (GNB) in hematological malignancies (HM) and hematopoietic stem cell transplant (HSCT) patients may differ according to geographic region. In addition, multidrug-resistant organisms (MDROs) may impact mortality. This is a prospective, observational, and multicenter study. The first episodes of bacteremia in adult patients with HM or HSCT were included. The risk factors for 30-day mortality were identified. One thousand two hundred and seventy-seven episodes were included (HM: 920; HSCT: 357). GNB were isolated in 60.3% of episodes, with Enterobacterales (46.9%) and P. aeruginosa (8.5%) being the most frequent. Gram-positive cocci were isolated in 41.9% of episodes, with coagulase-negative staphylococci (19.8%) and S. aureus (10.4%) being the most frequent. MDROs were isolated in 40.2% (24.4% GNB). The ARP of GNB in patients with HM vs. HSCT was cefepime: 36.8% vs. 45.7% (p = 0.026); piperacillin-tazobactam: 31.05% vs. 45.2% (p < 0.0001); carbapenems: 18.9% vs. 27.3% (p = 0.012); and aminoglycosides: 9.3% vs. 15.4% (p = 0.017), respectively. Overall mortality between patients with HM and HSCT was 17.5% vs. 17.6% (p = 0.951), respectively. The risk factors for mortality were relapsed and refractory underlying disease, corticosteroids use, respiratory source, septic shock, and GNB resistant to meropenem, while 7-day clinical response was a protective factor for survival. Bacteremia was frequently caused by GNB, with a large proportion of MDROs and a high level of antibiotic resistance, especially in patients with HSCT. Carbapenem-resistant GNB bacteremia was associated with a significant increase in mortality.

Lock, stock, and Leuconostoc: an unusual presentation of a rare pathogen

Leuconostoc mesenteroides is a Gram-positive bacterium in the Lactobacillaceae family. This species is rarely encountered clinically and in the past was regarded as a contaminant when cultured. Recently it is being recognized as a pathogen responsible for opportunistic infections in immunocompromised patients. Compared to other Gram-positive cocci, Leuconostoc spp. carry intrinsic resistance to vancomycin. It is not common for clinical microbiology laboratories to isolate this organism and instead incorrectly report enterococcus and streptococcus organisms. Here, we present a case of bacteremia resulting in febrile illness and pneumonia in an 81-year-old woman with a history of rheumatoid arthritis and a notable lapse between immunomodulator therapy exposure. She was successfully treated when this organism was identified, and her antibiotic therapy was switched from vancomycin to ampicillin-sulbactam. This case highlights the importance of considering L. mesenteroides as a source of infection in patients predisposed to an immunocompromised state despite this organism’s being a rare pathogen. Keywords: Leuconostoc mesenteroides, rheumatoid arthritis, immunomodulators; vancomycin resistance

Microbiota of goby fish in the northern part of the Caspian sea

Microorganisms, including bacteria of aquatic ecosystems, due to their short life cycle and rapid reproduction, react to any transformations of environmental conditions earlier than other organisms of any biocenosis. Various qualitative and quantitative changes in the bacteriocenoses of water and bottom sediments entail changes in the microbiota of aquatic organisms. Fish of the Gobiidae family, due to their sedentary lifestyle, can serve as an indicator of changes in the microbiota of the environment through the transformation of their own. The results of microbiological studies of goby fish caught in the northern part of the Caspian Sea in 2014–2023 are presented. The microbiota of organs and tissues of gobies changed insignificantly over the years at the level of the isolated families; microbial associations were similar in summer and autumn. In the autumn period, the qualitative composition of bacteriocenoses of all studied biotopes became more diverse in terms of the number of isolated genera of bacteria. Isolated microorganisms of gobies are represented by gram-positive and gram-negative forms with a dominance of representatives of the family. Enterobacteriaceae and gram-positive rods and cocci. The isolated bacteria had enzymatic activity — the production of a wide range of enzymes was recorded, including enzymes acting as pathogenicity factors. The presence of resistant isolates to most of the tested antibiotics was also noted. The above properties indicated significant heterogeneity of the population of isolated bacteria and their significant adaptive potential. The results obtained indicated the persistence of potentially dangerous microorganisms in gobies. The absence of clinical signs of infectious diseases and any pathological processes in the organs and tissues of the examined fish made it possible to assess the presence of the above microorganisms as asymptomatic bacterial carriage

The influence of professional oral hygiene on the indicators of local immunity

Professional oral hygiene is an important part of measures aimed at preventing and maintaining the patient’s health. Local immune response is the first barrier of immune protection capable of preventing infection diseases. The aim of the study - the influence of professional hygiene on the indicators of local immunity has been studied. The study involved two groups of patients: the first group included 19 individuals with chronic caries of varying depths (class I), and the second group comprised 15 individuals with moderate periodontal disease. To evaluate nonspecific oral protection, the index of natural colonization of the buccal epithelium and the activity of microbial adsorption by oral mucosal cells were assessed. Specific immunity was evaluated by measuring the concentration of immunoglobulins in unstimulated saliva. All indicators were recorded both before and after professional oral hygiene procedures. When studying the index of natural colonization of the buccal epithelium, it was found that professional cleaning in both groups led to normalization of the spectrum of bacteria adhered to the epithelium: there was a decrease in the amount of gram-negative microflora, atypical for this biotope, while maintaining a high adhesion index of gram-positive cocci. In persons with caries, before sanation, “unsatisfactory” resistance of oral mucosa was revealed in a third of the examined, after sanation, the number of such patients decreased by 3 times, with “satisfactory” resistance increased by 2 times. In the group with periodontal disease, all patients exhibited “unsatisfactory” mucosal resistance before the hygiene procedures. After sanitation, 20 % “unsatisfactory” resistance persisted. In the majority of patients (80 %), the resistance of the oral mucosa improved to “satisfactory”. The concentration of all classes of immunoglobulins in both groups before sanitation was significantly below the norm, after the measures taken, the indicators increased significantly and reached the level typical for healthy individuals. Carrying out professional cleaning of the teeth leads to the normalization of local immune status even without additional medical immunocorrection.

Performance of Gram Stain Characteristics for Predicting Culture Growth in Lower Respiratory Specimens Across Multiple Institutions

Abstract Data from Gram stains performed on clinical specimens can guide clinical decision-making and downstream laboratory workflows. However, the extent to which Gram stain results predict gold-standard culture results, and the generalizability of this performance across sites, warrants additional exploration. We sought to discover which Gram stain features would be associated with clinically significant culture growth (“growth”). To do so, 574 remnant specimens from the lower respiratory tract collected from four institutions were analyzed. A standardized Gram stain and culture protocol was performed across all study sites. Final reference organism identification was assigned using MALDI-ToF MS, and clinically significant growth was defined as any organism reported to the medical record. Gram stains with mixed microorganisms detected were considered concordant if ≥2 organisms of different Gram stain appearances were identified in culture. Growth was observed in 53% of specimens, including 25% of specimens in which Gram stain demonstrated no organisms. The 95% confidence intervals (CI) of the site-wise growth rates were 30-42%, 42-52%, 51-67%, and 60-77% (p &amp;lt; 0.001 by Chi-squared). By Gram stain morphology, 53-69% of specimens with Gram-positive cocci grew any clinically significant bacteria, while 31-49% grew a concordant Gram-positive cocci. 65-85% of specimens with Gram-negative bacilli grew any clinically significant bacteria, while 59-74% grew a concordant Gram-negative bacilli. 63-83% of specimens with mixed microorganisms grew 2 or more clinically relevant bacteria of differing Gram stain morphologies. Specimens from bronchoalveolar lavages (BALs) were less likely to have growth (30-42%) than endotracheal aspirates (66-77%). Polymorphonuclear leukocyte (PMNs) abundance was associated with culture growth, with Gram stains showing no, rare, few, moderate, or abundant PMNs demonstrating growth 28, 44, 52, 60, and 67% of the time (p &amp;lt; 0.001). Specimens with None and few squamous epithelial cells on Gram stain demonstrated growth 38-52% and 59-68% of the time (p &amp;lt; 0.001). No significant difference in growth was observed for red blood cells. Organism abundance on Gram stain was significantly associated with culture growth, with growth rate CIs being 20-32% for no organisms, 44-62% for rare, 58-77% for few, 70-93% for moderate, and 81-95% for abundant organisms seen. The extent to which these associations could guide the development of decision rules or machine learning models that demonstrate acceptable negative predictive value for pathogen growth to alleviate the operational burden of low-utility cultures is an exciting future direction to explore.