Multidrug-resistant bacterial infection in solid organ transplant recipients

Antibiotics and nano-antibiotics in treatment of lung infection: In management of COVID-19

The world has witnessed the cruelty of COVID-19 disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The association of COVID-19 with other secondary and bacterial co-infections has tremendously contributed to lung infections. An increased probability of having a secondary lung infection was observed among the post-COVID patients. The treatment of antibiotics has ameliorated the mortality rate. However, the stewardship of antibiotic treatment was linked to increased organ failure. Therefore, the paper discusses the interactions between the virus and host through the ACE2 receptors that contribute to COVID-19 development. Furthermore, the paper provides an invaluable compendium history of SARS-CoV-2 genomic composition. It revolves around most classes of antibiotics used to treat COVID-19 disease and post-COVID lung infections with the complete mechanism. This binds with the exertion of the antibiotics for bacterial infection associated with COVID-19 patients and how beneficial and effective responses have been recorded for the treatment. The application of nanotechnology and possible approaches of nanomedicines is also discussed to its potential usage.

Epidemiology and Prevention of Early Infections by Multi-Drug-Resistant Organisms in Adults Undergoing Liver Transplant: A Narrative Review

Invasive bacterial infections are a leading cause of morbidity and mortality after liver transplant (LT), especially during the first months after LT, and infections due to multi-drug-resistant organisms (MDRO) are increasing in this setting. Most of the infections in patients in intensive care unit arise from the endogenous microflora and, for this reason, pre-LT MDRO rectal colonization is a risk factor for developing MDRO infections in the post-LT. Moreover, the transplanted liver may carry an increased risk of MDRO infections due to organ transportation and preservation, to donor intensive care unit stay and previous antibiotic exposure. To date, little evidence is available about how MDRO pre-LT colonization in donors and recipients should address LT preventive and antibiotic prophylactic strategies, in order to reduce MDRO infections in the post-LT period. The present review provided an extensive overview of the recent literature on these topics, with the aim to offer a comprehensive insight about the epidemiology of MDRO colonization and infections in adult LT recipients, donor-derived MDRO infections, possible surveillance, and prophylactic strategies to reduce post-LT MDRO infections.

Surgical site infection following pancreaticoduodenectomy in a referral cancer center in Mexico

BACKGROUND

Pancreaticoduodenectomy is the standard treatment for resectable periampullary cancer. Surgical site infections (SSI) are common complications with increased morbidity. The study aimed to describe the prevalence, risk factors, microbiology, and outcomes of SSI among patients undergoing pancreaticoduodenectomy.

METHODS

We conducted a retrospective study in a referral cancer center between January 2015 and June 2021. We analyzed baseline patient characteristics and SSI occurrence. Culture results and susceptibility patterns were described. Multivariate logistic regression was used to determine risk factors, proportional hazards model to evaluate mortality, and Kaplan-Meier analysis to assess long-term survival.

RESULTS

A total of 219 patients were enrolled in the study; 101 (46%) developed SSI. Independent factors for SSI were diabetes mellitus, preoperative albumin level, biliary drainage, biliary prostheses, and clinically relevant postoperative pancreatic fistula. The main pathogens were Enterobacteria and Enterococci. Multidrug-resistance rate in SSI was high but not associated with increased mortality. Infected patients had higher odds of sepsis, longer hospital stay and intensive care unit stay, and readmission rate. Neither 30-day mortality nor long-term survival was significantly different between infected and non-infected patients.

CONCLUSIONS

SSI prevalence among patients undergoing pancreaticoduodenectomy was high and largely caused by resistant microorganisms. Most risk factors were related to preoperative instrumentation of the biliary tree. SSI was associated with greater risk of unfavorable outcomes; however, survival was unaffected.

Adherence to Human Colon Cells by Multidrug Resistant Enterobacterales Strains Isolated From Solid Organ Transplant Recipients With a Focus on Citrobacter freundii

Enterobacteria species are common causes of hospital-acquired infections, which are associated with high morbidity and mortality rates. Immunocompromised patients such as solid organ transplant (SOT) recipients are especially at risk because they are frequently exposed to antibiotics in the course of their treatments. In this work, we used a collection of 106 Escherichia coli, 78 Klebsiella pneumoniae, 25 Enterobacter spp., and 24 Citrobacter spp. multidrug resistant strains isolated from transplant patients (hepatic, renal or renal/pancreatic) in order to examine their ability to adhere in vitro to HT-29 human colon cells, and to determine if some adhesive characteristics are associated with prevalence and persistence of these strains. A total of 33 E. coli (31%), 21 K. pneumoniae (27%), 7 Enterobacter spp. (28%), and 5 Citrobacter spp. (21%), adhered to the colon epithelial cells. Two main adherence patterns were observed in the four species analyzed, diffuse adherence, and aggregative adherence. Under transmission electronic microscopy (TEM), most bacteria lacked visible fimbria on their surface, despite their strong adherence to epithelial cells. None of the strains studied was able to induce any cytotoxic effect on HT-29 cells although some of them strongly colonizing both cells and glass coverslips at high density. Some of the strains failed to adhere to the epithelial cells but adhered strongly to the cover-slide, which shows that microscopy studies are mandatory to elucidate the adherence of bacteria to epithelial cells in vitro, and that quantitative assays using colony forming unit (CFUs) counting need to be supplemented with pictures to determine definitively if a bacterial strain adheres or not to animal cells in vitro. We report here, for the first time, the aggregative adherence pattern of two multidrug resistant (MDR) Citrobacter freundii strains isolated from human patients; importantly, biofilm formation in Citrobacter is totally dependent on the temperature; strong biofilms were formed at room temperature (RT) but not at 37°C, which can play an important role in the colonization of hospital surfaces. In conclusion, our results show that there is a great variety of adhesion phenotypes in multidrug-resistant strains that colonize transplanted patients.

An Update in Antimicrobial Therapies and Infection Prevention in Pediatric Lung Transplant Recipients

Lung transplantation can offer life-prolonging therapy to children with otherwise terminal end-stage lung disease. However, infectious complications, like those experienced by their adult counterparts, are a significant cause of morbidity and mortality. These include bacteria, viruses, and fungi that infect the patient pretransplant and those that may be acquired from the donor or by the recipient in the months to years posttransplant. An understanding of the approach to the management of each potential infecting organism is required to ensure optimal outcomes. In particular, emphasis on aggressive preoperative management of infections in pediatric patients with cystic fibrosis is important. These include multidrug-resistant Gram-negative bacteria, fungi, and Mycobacterium abscessus, the posttransplant outcome of which depends on optimal pretransplant management, including vaccination and other preventive, antibiotic-sparing strategies. Similarly, increasing the transplant donor pool to meet rising transplant demands is an issue of critical importance. Expanded-criteria donors-those at increased risk of blood-borne viruses in particular-are increasingly being considered and transplants undertaken to meet the rising demand. There is growing evidence in the adult pool that these transplants are safe and associated with comparable outcomes. Pediatric transplanters are therefore likely to be presented with increased-risk donors for their patients. Finally, numerous novel antibiotic-sparing therapeutic approaches are on the horizon to help combat infections that currently compromise transplant outcomes.

Management of multidrug resistant Gram-negative bacilli infections in solid organ transplant recipients: SET/GESITRA-SEIMC/REIPI recommendations

Solid organ transplant (SOT) recipients are especially at risk of developing infections by multidrug resistant (MDR) Gram-negative bacilli (GNB), as they are frequently exposed to antibiotics and the healthcare setting, and are regulary subject to invasive procedures. Nevertheless, no recommendations concerning prevention and treatment are available. A panel of experts revised the available evidence; this document summarizes their recommendations: (1) it is important to characterize the isolate's phenotypic and genotypic resistance profile; (2) overall, donor colonization should not constitute a contraindication to transplantation, although active infected kidney and lung grafts should be avoided; (3) recipient colonization is associated with an increased risk of infection, but is not a contraindication to transplantation; (4) different surgical prophylaxis regimens are not recommended for patients colonized with carbapenem-resistant GNB; (5) timely detection of carriers, contact isolation precautions, hand hygiene compliance and antibiotic control policies are important preventive measures; (6) there is not sufficient data to recommend intestinal decolonization; (7) colonized lung transplant recipients could benefit from prophylactic inhaled antibiotics, specially for Pseudomonas aeruginosa; (8) colonized SOT recipients should receive an empirical treatment which includes active antibiotics, and directed therapy should be adjusted according to susceptibility study results and the severity of the infection.

Travel vaccination recommendations and endemic infection risks in solid organ transplantation recipients

BACKGROUND

Solid organ transplant (SOT) recipients are often heavily immunosuppressed and consequently at risk of serious illness from vaccine preventable viral and bacterial infections or with endemic fungal and parasitic infections. We review the literature to provide guidance regarding the timing and appropriateness of vaccination and pathogen avoidance related to the immunological status of SOT recipients.

METHODS

A PUBMED search ([Vaccination OR vaccine] AND/OR ["specific vaccine"] AND/OR [immunology OR immune response OR cytokine OR T lymphocyte] AND transplant was performed. A review of the literature was performed in order to develop recommendations on vaccination for SOT recipients travelling to high-risk destinations.

RESULTS

Whilst immunological failure of vaccination in SOT is primarily the result of impaired B-cell responses, the role of T-cells in vaccine failure and success remains unknown. Vaccination should be initiated at least 4 weeks prior to SOT or more than 6 months post-SOT. Avoidance of live vaccination is generally recommended, although some live vaccines may be considered in the specific situations (e.g. yellow fever). The practicing physician requires a detailed understanding of region-specific endemic pathogen risks.

CONCLUSIONS

We provide a vaccination and endemic pathogen guide for physicians and travel clinics involved in the care of SOT recipients. In addition, recommendations based on timing of anticipated immunological recovery and available evidence regarding vaccine immunogenicity in SOT recipients are provided to help guide pre-travel consultations.

The Distribution and Resistance of Pathogens Among Solid Organ Transplant Recipients with Pseudomonas aeruginosa Infections

Background

Pseudomonas aeruginosa infection remains a life-threatening complication after solid organ transplantation (SOT). We aimed to investigate the distribution and drug susceptibility of pathogens, and clinical characteristics of SOT recipients with Pseudomonas aeruginosa infections.

Material/Methods

A total of 55 SOT recipients who developed 61 episodes of Pseudomonas aeruginosa infections between January 1, 2003 and July 31, 2015 were retrospectively analyzed. The distribution and the drug susceptibility of Pseudomonas aeruginosa were reviewed.

Results

The most common site from which 61 Pseudomonas aeruginosa rods were isolated were the lungs (57.4%, n=37), followed by the blood (27.9%, n=17). There were 35, 18, and 9 recipients accompanied with a serum creatinine level of >1.5 mg/dL, lymphocyte count of <300/mm³, and a serum albumin level of <30 g/L, respectively. Seven patients each presented with white blood cell count of >15 000/mm³ and platelet count of <50 000/mm³. There were 6 (10.9%) cases of septic shocks and 18 (32.7%) deaths. Antibiotic resistance rate of all Pseudomonas aeruginosa to 4 of 10 antibiotics investigated was more than 50%. Of these 61 Pseudomonas aeruginosa isolates, 47.5% were carbapenem-resistant. The rods were relatively sensitive to piperacillin-tazobactam, levofloxacin, amikacin, and cefoperazone-sulbactam (resistance rate <40%).

Conclusions

The clinical presentation of Pseudomonas aeruginosa infections included high body temperature, decreased platelet count, elevated white blood cell count, a high nosocomial origin and mortality, and onset in the late period after transplantation. According to our findings, piperacillin-tazobactam, levofloxacin, amikacin, and cefoperazone-sulbactam, alone or combination, are recommended to treat SOT recipients with Pseudomonas aeruginosa infections.

Incidence, risk factors, microbiology of venous catheter associated bloodstream infections--a prospective study from a tertiary care hospital

PURPOSE

Central venous catheters (CVCs) though indispensable in current medical and intensive care treatment, also puts patients at risk of catheter related infection (CRI) resulting in increased morbidity and mortality. We analysed the incidence, risk factors, bacteriological profile and antimicrobial susceptibility pattern of the isolates in central venous catheter associated bloodstream infection (CVC-BSI) in the intensive care unit (ICU) patients and studied the formation of biofilm in CVCs.

MATERIALS AND METHODS

The following case control study included 115 patients with CVC in situ. Quantitative blood cultures (QBC) and catheter tip cultures were performed for the diagnoses. Direct catheter staining was done for an early diagnosis by acridine orange (AO) and Gram staining methods. Biofilm production in catheters was detected by 'tissue culture plate' (TCP) method. The results were analysed using the computer-based program statistical package for the social sciences (SPSS).

RESULTS

In 25/115 patients, definite diagnosis of CVC-BSI was made. The mean age was 48.44 ± 17.34 years (cases) vs 40.10 ± 18.24 years (controls) and the mean duration of catheterisation was 25.72 ± 8.73 days (cases) vs 11.89 ± 6.38 days (controls). Local signs of infection (erythema, tenderness and oozing) were found more significantly in CVC-BSI cases. The AO staining was more sensitive and Gram staining of catheters showed higher specificity. Staphylococcus aureus followed by Pseudomonas aeruginosa and non-albicans Candida were common CVC-BSI pathogens. Multidrug-resistant (MDR) strains were isolated in bacterial agents of CVC-BSI. Non-albicans Candida and Enterococcus faecalis showed strong biofilm production.

CONCLUSION

The incidence of CVC-BSI was 21.73% and the rate was 14.59 per 1000 catheter days. Prolonged ICU stay and longer catheterisation were major risk factors. S. aureus was isolated most commonly in CVC-BSI cases. The menace of multidrug resistance and biofilm formation in CVCs is associated with CVC-BSI.

Management of urinary tract infection in solid organ transplant recipients: Consensus statement of the Group for the Study of Infection in Transplant Recipients (GESITRA) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and the Spanish Network for Research in Infectious Diseases (REIPI)

BACKGROUND

Urinary tract infections (UTIs) are one of the most common infections in solid organ transplant (SOT) recipients.

METHODS

Experienced SOT researchers and clinicians have developed and implemented this consensus document in support of the optimal management of these patients. A systematic review was conducted, and evidence levels based on the available literature are given for each recommendation. This article was written in accordance with international recommendations on consensus statements and the recommendations of the Appraisal of Guidelines for Research and Evaluation II (AGREE II).

RESULTS

Recommendations are provided on the management of asymptomatic bacteriuria, and prophylaxis and treatment of UTI in SOT recipients. The diagnostic-therapeutic management of recurrent UTI and the role of infection in kidney graft rejection or dysfunction are reviewed. Finally, recommendations on antimicrobials and immunosuppressant interactions are also included.

CONCLUSIONS

The latest scientific information on UTI in SOT is incorporated in this consensus document.

Infections after orthotopic liver transplantation

Opportunistic infections are a leading cause of morbidity and mortality after orthotopic liver transplantation. Systemic immunosuppression renders the liver recipient susceptible to de novo infection with bacteria, viruses and fungi post-transplantation as well to reactivation of pre-existing, latent disease. Pathogens are also transmissible via the donor organ. The time from transplantation and degree of immunosuppression may guide the differential diagnosis of potential infectious agents. However, typical systemic signs and symptoms of infection are often absent or blunted after transplant and a high index of suspicion is needed. Invasive procedures are often required to procure tissue for culture and guide antimicrobial therapy. Antimicrobial prophylaxis reduces the incidence of opportunistic infections and is routinely employed in the care of patients after liver transplant. In this review, we survey common bacterial, fungal, and viral infections after orthotopic liver transplantation and highlight recent developments in their diagnosis and management.

Central memory CD8+ T lymphocytes mediate lung allograft acceptance

Memory T lymphocytes are commonly viewed as a major barrier for long-term survival of organ allografts and are thought to accelerate rejection responses due to their rapid infiltration into allografts, low threshold for activation, and ability to produce inflammatory mediators. Because memory T cells are usually associated with rejection, preclinical protocols have been developed to target this population in transplant recipients. Here, using a murine model, we found that costimulatory blockade-mediated lung allograft acceptance depended on the rapid infiltration of the graft by central memory CD8+ T cells (CD44(hi)CD62L(hi)CCR7+). Chemokine receptor signaling and alloantigen recognition were required for trafficking of these memory T cells to lung allografts. Intravital 2-photon imaging revealed that CCR7 expression on CD8+ T cells was critical for formation of stable synapses with antigen-presenting cells, resulting in IFN-γ production, which induced NO and downregulated alloimmune responses. Thus, we describe a critical role for CD8+ central memory T cells in lung allograft acceptance and highlight the need for tailored approaches for tolerance induction in the lung.

The role of the clinical microbiology laboratory in solid organ transplantation programs

Infections remain a major complication of solid organ transplantation. For this reason, the clinical microbiology laboratory plays a key role in the success of transplant programs, which must have the support of a qualified laboratory, both technically and professionally. Transplant programs strongly condition the structure and functionality of microbiology laboratories, but at the same time, benefit greatly from the knowledge generated from these programs. The laboratory must make a special effort to implement rapid methods that can respond to the broad spectrum of potential pathogens in solid organ transplant patients. The integration of microbiologists in multidisciplinary teams is highly recommended, as only then can they obtain the highest quality and efficiency in the diagnostic process. This article provides an updated review of the techniques to be used once transplantation has occurred. The role of the microbiologist is also crucial in the pretransplant period, as good microbiological candidate evaluation at this time strongly conditions the success of the transplantation program.