Gram-negative Bacteria Colonization Research Articles

Multidrug-resistant Gram-negative bacterial colonization in patients, carriage by healthcare workers and contamination of hospital environments in Ghana

BackgroundPatients already colonized with multidrug-resistant (MDR) Gram-negative bacteria (GNB) on admission to critical care units may be an important source of transmission of these bacteria in hospitals. We sought to determine the prevalence of MDR GNB colonization in patients, staff and the ward environment and to assess the risk factors for colonization of patients in wards. MethodsThe study was conducted from April 2021 to July 2021 in a teaching hospital in Ghana. MDR GNB were isolated from rectal, and hand swabs were taken from patients on admission and after 48 h. Swabs from HCW’s hands and the ward environment were also taken. Risk factors for colonization with MDR GNB were assessed using univariate and multivariate analysis. ResultsMDR GNB rectal colonization rate among patients was 50.62% on admission and 44.44% after 48 h. MDR GNB were isolated from 6 (5.26%) and 24 (11.54%) of HCW’s hand swabs and environmental swabs, respectively. Previous hospitalization (p-value = 0.021, OR, 95% CI= 7.170 (1.345–38.214) was significantly associated with colonization by MDR GNB after 48 h of admission. Age (21–30 years) (p-value = 0.022, OR, 95% CI = 0.103 (0.015–0.716) was significantly identified as a protective factor associated with a reduced risk of rectal MDR GNB colonization. ConclusionThe high colonization of MDR GNB in patients, the carriage of MDR GNB on HCW’s hands, and the contamination of hospital environments highlights the need for patient screening and stringent infection prevention and control practices to prevent the spread of MDR GNB in hospitals.

High Burden of Intestinal Colonization With Antimicrobial-Resistant Bacteria in Chile: An Antibiotic Resistance in Communities and Hospitals (ARCH) Study.

Antimicrobial resistance is a global threat, heavily impacting low- and middle-income countries. This study estimated antimicrobial-resistant gram-negative bacteria (GNB) fecal colonization prevalence in hospitalized and community-dwelling adults in Chile before the coronavirus disease 2019 pandemic. From December 2018 to May 2019, we enrolled hospitalized adults in 4 public hospitals and community dwellers from central Chile, who provided fecal specimens and epidemiological information. Samples were plated onto MacConkey agar with ciprofloxacin or ceftazidime added. All recovered morphotypes were identified and characterized according to the following phenotypes: fluoroquinolone-resistant (FQR), extended-spectrum cephalosporin-resistant (ESCR), carbapenem-resistant (CR), or multidrug-resistant (MDR; as per Centers for Disease Control and Prevention criteria) GNB. Categories were not mutually exclusive. A total of 775 hospitalized adults and 357 community dwellers were enrolled. Among hospitalized subjects, the prevalence of colonization with FQR, ESCR, CR, or MDR-GNB was 46.4% (95% confidence interval [CI], 42.9-50.0), 41.2% (95% CI, 37.7-44.6), 14.5% (95% CI, 12.0-16.9), and 26.3% (95% CI, 23.2-29.4). In the community, the prevalence of FQR, ESCR, CR, and MDR-GNB colonization was 39.5% (95% CI, 34.4-44.6), 28.9% (95% CI, 24.2-33.6), 5.6% (95% CI, 3.2-8.0), and 4.8% (95% CI, 2.6-7.0), respectively. A high burden of antimicrobial-resistant GNB colonization was observed in this sample of hospitalized and community-dwelling adults, suggesting that the community is a relevant source of antibiotic resistance. Efforts are needed to understand the relatedness between resistant strains circulating in the community and hospitals.

Predicting infection risk from surveillance cultures: frustrating or foretelling?

The global burden of morbidity and mortality due to multidrug-resistant infections is high, and in-vitro inactive empirical antibiotic therapy is a well known risk factor for poor outcomes. 1 Antimicrobial Resistance CollaboratorsGlobal burden of bacterial antimicrobial resistance in 2019: a systematic analysis. Lancet. 2022; 399: 629-655 Summary Full Text Full Text PDF PubMed Scopus (1171) Google Scholar , 2 Kadri SS Lai YL Warner S et al. Inappropriate empirical antibiotic therapy for bloodstream infections based on discordant in-vitro susceptibilities: a retrospective cohort analysis of prevalence, predictors, and mortality risk in US hospitals. Lancet Infect Dis. 2021; 21: 241-251 Summary Full Text Full Text PDF PubMed Scopus (57) Google Scholar Studies have shown that colonisation with resistant pathogens increases the subsequent risk of infection by those same strains. However, when operationalising this principle, deciding how often to use specific broad-spectrum antibiotics if the patient is colonised with a particular pathogen warrants an improved understanding of the relative size of infection risks across different pathogens, host types, and time. 3 Denkel LA Maechler F Schwab F et al. Infections caused by extended-spectrum beta-lactamase-producing Enterobacterales after rectal colonization with ESBL-producing Escherichia coli or Klebsiella pneumoniae. Clin Microbiol Infect. 2020; 26: 1046-1051 Summary Full Text Full Text PDF PubMed Scopus (18) Google Scholar , 4 Tseng W-P Chen Y-C Chen S-Y Chen S-Y Chang S-C Risk for subsequent infection and mortality after hospitalization among patients with multidrug-resistant Gram-negative bacteria colonization or infection. Antimicrob Resist Infect Control. 2018; 7: 93 Crossref PubMed Scopus (33) Google Scholar , 5 Giannella M Bartoletti M Conti M Righi E Carbapenemase-producing Enterobacteriaceae in transplant patients. J Antimicrob Chemother. 2021; 76: i27-i39 Crossref Scopus (6) Google Scholar , 6 Tischendorf J de Avila RA Safdar N Risk of infection following colonization with carbapenem-resistant Enterobactericeae: a systematic review. Am J Infect Control. 2016; 44: 539-543 Summary Full Text Full Text PDF PubMed Scopus (143) Google Scholar Roel P J Willems and colleagues should be congratulated for their systematic review and meta-analysis establishing the cumulative incidence risk and the incidence density of infection in patients with multidrug-resistant Gram-negative bacteria (MDR-GNB) or vancomycin-resistant enterococci (VRE) colonisation of the gastrointestinal or urinary tract. 7 Willems RPJ van Dijk K Vehreschild MJGT et al. Incidence of infection with multidrug-resistant Gram-negative bacteria and vancomycin-resistant enterococci in carriers: a systematic review and meta-regression analysis. Lancet Infect Dis. 2022; (published online Jan 30.)https://doi.org/10.1016/S1473-3099(22)00811-8 Google Scholar Willems and colleagues pool aggregate results from 40 observational studies contributing 5015 VRE carriers and 9034 MDR-GNB carriers with a median study duration of 45 days (IQR 28–140). 7 Willems RPJ van Dijk K Vehreschild MJGT et al. Incidence of infection with multidrug-resistant Gram-negative bacteria and vancomycin-resistant enterococci in carriers: a systematic review and meta-regression analysis. Lancet Infect Dis. 2022; (published online Jan 30.)https://doi.org/10.1016/S1473-3099(22)00811-8 Google Scholar Infection and colonisation were as defined by the authors of each respective study and varied across studies. Incidence of infection with multidrug-resistant Gram-negative bacteria and vancomycin-resistant enterococci in carriers: a systematic review and meta-regression analysisThe risk of infection was substantial, with the highest risk for patients colonised with carbapenem-resistant Gram-negative bacteria and the lowest in patients with VRE. These data might help to guide prophylactic and treatment decisions and form a valuable resource for planning clinical trials on targeted prevention. Full-Text PDF

Third-generation cephalosporin resistant gram-negative bacteraemia in patients with haematological malignancy; an 11-year multi-centre retrospective study

ObjectivesAmong patients with haematological malignancy, bacteraemia is a common complication during chemotherapy-induced neutropenia. Resistance of gram-negative bacteria (GNB) to third-generation cephalosporins (3GC) is increasing. In order to explore the value of using surveillance cultures to guide empirical treatment e.g. choosing between carbapenem versus ceftazidime- we aimed to assess the distribution of pathogens causing bacteraemia in patients with haematological malignancy, and the proportion of 3GC-resistant GNB (3GC-R GNB) bacteraemia that was preceded by 3GC-R GNB colonization.MethodsUsing 11 years of data (2008–2018) from the Dutch national antimicrobial resistance surveillance system, we assessed the prevalence of 3GC-R GNB in episodes of bacteraemia, and the proportion of 3GC-R GNB bacteraemia that was preceded by 3GC-R GNB colonization. Colonization was defined as availability of any GNB surveillance isolate in the year before, independent of the causative micro-organism (time-paired isolates).ResultsWe included 3887 patients, representing 4142 episodes of bacteraemia. GNB were identified in 715/4142 (17.3%), of which 221 (30.9%) were 3GC-R GNB. In 139 of these 221 patients a time-paired surveillance culture was available. In 76.2% (106/139) of patients these surveillance cultures already showed 3GC-R GNB isolates in the year prior to the culture date of the 3GC-R GNB positive blood isolate.ConclusionsThis multi-centre study shows that in patients with haematological malignancy, the majority of 3GC-R GNB bacteraemia is preceded by 3GC-R GNB colonization. Prospective clinical studies are needed to assess the safety and benefits of the use of surveillance-cultures to guide empirical therapy to restrict the empirical use of carbapenems in this population.

Clinical Impact of Colonization with Carbapenem-Resistant Gram-Negative Bacteria in Critically Ill Patients Admitted for Severe Trauma.

Multidrug-resistant (MDR) Gram-negative bacteria (GNB) have raised concerns as common, frequent etiologic agents of nosocomial infections, and patients admitted to intensive care units (ICUs) present the highest risk for colonization and infection. The incidence of colonization and infection in trauma patients remains poorly investigated. The aim of this study was to assess the risk factors for Carbapenem-resistant (CR)-GNB colonization and the clinical impact of colonization acquisition in patients with severe trauma admitted to the ICU in a CR-GNB hyperendemic country. This is a retrospective observational study; clinical and laboratory data were extracted from the nosocomial infection surveillance system database. Among 54 severe trauma patients enrolled in the study, 28 patients were colonized by CR-GNB; 7 (12.96%) patients were already colonized at ICU admission; and 21 (38.89%) patients developed a new colonization during their ICU stay. Risk factors for colonization were the length of stay in the ICU (not colonized, 14.81 days ± 9.1 vs. colonized, 38.19 days ± 27.9; p-value = 0.001) and days of mechanical ventilation (not colonized, 8.46 days ± 7.67 vs. colonized, 22.19 days ± 15.09; p-value < 0.001). There was a strong statistical association between previous colonization and subsequent development of infection (OR = 80.6, 95% CI 4.5-1458.6, p-value < 0.001). Factors associated with the risk of infection in colonized patients also included a higher Charlson comorbidity index, a longer length of stay in the ICU, a longer duration of mechanical ventilation, and a longer duration of treatment with carbapenem and vasopressors (not infected vs. infected: 0(0-4) vs. 1(0-3), p = 0.012; 24.82 ± 16.77 vs. 47 ± 28.51, p = 0.016; 13.54 ± 15.84 vs. 31.7 ± 16.22, p = 0.008; 1.09 ± 1.14 vs. 7.82 ± 9.15, p = 0.008). The adoption of MDR-GNB colonization prevention strategies in critically ill patients with severe trauma is required to improve the quality of care and reduce nosocomial infections, length of hospital stay and mortality.

Multidrug-Resistant Gram-Negative Bacteria in Burn Patients.

Patients with burn injuries are at high risk for infectious complications, and infections are the most common cause of death after the first 72 h of hospitalization. Hospital-acquired infections caused by multidrug resistant (MDR) Gram-negative bacteria (GNB) in this population are concerning. Here, we evaluated carriage with MDR GNB in patients in a large tertiary-care burn intensive care unit. Twenty-nine patients in the burn unit were screened for intestinal carriage. Samples were cultured on selective media. Median time from admission to the burn unit to first sample collection was 9 days (IQR 5 - 17 days). In 21 (72%) patients, MDR GNB were recovered; the most common bacterial species isolated was Pseudomonas aeruginosa, which was found in 11/29 (38%) of patients. Two of these patients later developed bloodstream infections with P. aeruginosa. Transmission of KPC-31-producing ST22 Citrobacter freundii was detected. Samples from two patients grew genetically similar C. freundii isolates that were resistant to ceftazidime-avibactam. On analysis of whole-genome sequencing, blaKPC-31 was part of a Tn4401b transposon that was present on two different plasmids in each C. freundii isolate. Plasmid curing experiments showed that removal of both copies of blaKPC-31 was required to restore susceptibility to ceftazidime-avibactam. In summary, MDR GNB colonization is common in burn patients and patient-to-patient transmission of highly resistant GNB occurs. These results emphasize the ongoing need for infection prevention and antimicrobial stewardship efforts in this highly vulnerable population.

Donor to Recipient Transmission of Bacterial Pathogens in Relation to Cold Ischemic Time in Lung Transplantation

<h3>Purpose</h3> To evaluate the effect of cold ischemic time (CIT) on donor pathogen transmission after lung transplantation (LTx). <h3>Methods</h3> We reviewed data of 59 patients from 2011 to 2018 and analyzed the cultures results of donor bronchial aspirate (DBA), graft endobronchial bacterial swab (GEBS), recipient bacterial status before transplantation (RBT) and postoperative recipient bronchial aspirate (RBA) in relation to donor hospital length of stay (LOS), CIT and to recipient intubation time, Intensive Care Unit (ICU) and hospital LOS, perioperative and infection related deaths. The groups were compared using Mann-Withney U test and Fisher's exact test, death risk was analyzed as hazard ratio with 95% CI. <h3>Results</h3> Single LTx was in 17 cases, bilateral LTx in 42. First/only lung CIT1 was 403±107 min, second lung CIT2 - 541±114 min (the data are shown as mean ± Standard Deviation) . Cultures were positive in 42,2% DBA, 83,1% GEBS, 79,7% RTB, 33,9% RBA. Longer donor hospital LOS (132±52 v.100±79 hrs) was associated with isolation of DBA Gram-negative bacteria (n=16), especially <i>A. baumannii</i>). Longer CIT2 (600±109 v. 518±108 min) was related to Gram-positive bacteria other than MSSA in GEBS and it caused recipient's longer ICU LOS (21±18 v. 10±13 days). Longer CIT1 (476±113 v. 388±100 min) and CIT2 (613±91 v. 522±113 min) was associated with growing the new pathogens in RBA. Longer CIT1 (440±102 v. 374±102 min) and CIT2 (584±101 v. 498±111 min) caused prolonged recipient intubation time above 3 days (n=26) and CIT2 (607±93 v. 521±113 min) was related to recipient perioperative death (n=10), but these two factors were not affected by positive DBA, GEBS nor RBA.. Recipient infection deaths (n=4), recipient ICU LOS above 7 days (n=21) and hospital LOS above 30 days (n=30) were not related to DBA, GEBS nor RBA. Positive DBA, GEBS and RBA did not increase recipient death risk - HR 0,690; 0,348 and 1,369 respectively. <h3>Conclusion</h3> The cultures GEBS brought more information than DBA. Longer CIT increased Gram-positive bacteria load other than MSSA in GEBS<i>.</i> Donor hospital LOS was correlated with Gram-negative bacteria colonization. Positive cultures of DBA, GEBS, RBA did not affect recipient intubation time, ICU and hospital LOS, perioperative or infection related deaths.

Effect of Hcp Iron Ion Regulation on the Interaction Between Acinetobacter baumannii With Human Pulmonary Alveolar Epithelial Cells and Biofilm Formation.

Acinetobacter baumannii is a type of bacterial nosocomial infection with severe drug resistance. Hemolysin co-regulated protein (Hcp) is a marker of activated type VI secretion system (T6SS), a key secretory system that promotes Gram-negative bacteria colonization, adhesion, and invasion of host cells. Hcp is also regulated by iron ions (Fe). In this study, an ATCC17978 hcp deletion strain (ATCC17978Δhcp), an hcp complement strain (ATCC17978Δhcp+ ), and an A. baumannii–green fluorescent protein (GFP) strain were constructed and used to investigate the role of hcp in bacterial adhesion to cells (human pulmonary alveolar epithelial cells (HPAEpiC)) and biofilm formation. Our results indicate that the inhibitory concentrations of the three A. baumannii strains (ATCC17978 wild type, ATCC17978Δhcp, and ATCC17978Δhcp +) were drug-sensitive strains. A. baumannii hcp gene and iron ions might be involved in promoting the formation of a biofilm and host–bacteria interaction. Iron ions affected the ability of A. baumannii to adhere to cells, as there was no significant difference in the bacterial numbers when assessing the adhesion of the three strains to HPAEpiC in the presence of iron ion concentrations of 0 μM (F = 3.1800, p = 0.1144), 25 μM (F = 2.067, p = 0.2075), 100 μM (F = 30.52, p = 0.0007), and 400 μM (F = 17.57, p = 0.0031). The three strains showed significant differences in their ability to adhere to HPAEpiC. The numbers of bacteria adhesion to HPAEpiC were ATCC17978Δhcp>ATCC17978Δhcp +>ATCC17978 in descending order. Hcp gene was positively regulated by iron ions in the bacteria–cells’ co-culture. It is speculated that the effect of iron ions on the interaction between A. baumannii and HPAEpiC might be related to the transport function of hcp and bacterial immune escape mechanisms.

Clinical characteristics and risk factors for the isolation of multi-drug-resistant Gram-negative bacteria from critically ill patients with COVID-19

BackgroundWe investigated the clinical characteristics and risk factors for the isolation of multi-drug-resistant (MDR) Gram-negative bacteria (GNB) from critically ill COVID-19 patients.MethodsWe retrospectively matched (1:2) critical COVID-19 patients with one or more MDR GNB from any clinical specimen (cases), with those with no MDR GNB isolates (controls).ResultsSeventy-eight cases were identified (4.5 per 1000 intensive care unit (ICU) days, 95% confidence interval (CI) 3.6–5.7). Of 98 MDR GNB isolates, the most frequent species were Stenotrophomonas maltophilia (24, 24.5%), and Klebsiella pneumoniae (23, 23.5%). Two (8.7%) K. pneumoniae, and six (85.7%) Pseudomonas aeruginosa isolates were carbapenem resistant. A total of 24 (24.5%) isolates were not considered to be associated with active infection. Those with active infection received appropriate antimicrobial agents within a median of one day. The case group had significantly longer median central venous line days, mechanical ventilation days, and hospital length of stay (P<0.001 for each). All-cause mortality at 28 days was not significantly different between the two groups (P=0.19). Mechanical ventilation days (adjusted odds ratio 1.062, 95% CI 1.012–1.114; P=0.015), but not receipt of corticosteroids or tocilizumab, was independently associated with the isolation of MDR GNB. There was no association between MDR GNB and 28-day all-cause mortality (adjusted odds ratio 2.426, 95% CI 0.833–7.069; P= 0.104).ConclusionIn critically ill COVID-19 patients, prevention of MDR GNB colonization and infections requires minimizing the use of invasive devices, and to remove them as soon as their presence is no longer necessary.

Staphylococcus aureus colonization increases the risk of bacteremia in hemodialysis patients: a molecular epidemiology approach with time-dependent analysis

Bacteremia is the second cause of death in hemodialysis patients and colonization may be a risk factor. We analyzed the association between Staphylococcus aureus or multidrug-resistant Gram-negative bacteria colonization and bacteremia in hemodialysis patients. A prospective cohort study was conducted. Colonization status was determined at baseline, 2, and 6 months later. The time-to-first-bacteremia was analyzed using the baseline status and time-dependent nature of colonization. The recurrence of bacteremia given colonization status was evaluated using a Poisson regression model. The genetic relatedness between isolates that colonized and caused bacteremia were established by molecular typing methods. Seventy-one patients developed bacteremia over the course of follow-up, with the majority of cases being caused by S aureus (n = 28; 39.4%) and only three caused by multidrug-resistant Gram-negative bacteria. S aureus colonization was associated with an increased risk of bacteremia in time-dependent analysis (HR:4.64; 95%CI: 1.72-12.53) and with recurrence of infection in Poisson model (IRR:5.90, 95%CI: 2.29-15.16). Molecular methods revealed that 77.8% of patients with S aureus bacteremia were colonized with the same strain that caused the infection. S aureus is a cause of endogenous infection in hemodialysis patients. Colonization is associated with both time-to-first-bacteremia and the recurrence of infection. The prompt identification of colonized patients and the evaluation of decolonization protocols are needed.

THE CORRELATION BETWEEN BACTERIAL COLONIZATION AND INTERLEUKIN-8 SERUM LEVELS IN ACUTE EXACERBATION OF COPD

Background: One of the causes of AECOPD is bacterial infection. Increased bacterial colonization may trigger activation of macrophages so that there is an increase in the number of inflammatory mediators, one of which is Interleukin-8 (IL-8). Elevation of IL-8 serum levels may worsen the symptoms of COPD. This study measured IL-8 serum levels in subjects who had exacerbations. Methods: An analytical research with Cross Sectional design. The reseacrh subjects were AECOPD patients who visited Dr. Wahidin Sudirohusodo Hospital, Makassar, Indonesia. Sputum culture was examined to assess the type of bacterial colonization and serum examinated to asses the Interleukin-8 serum levels. Results: The subjects were 65 patients. AECOPD is generally found in 62 men (95.4%), most were age>60 years 48 patients (73.8%). For severity we found 52 patients were categorized as group D (80%). The highest number of subjects with bacterial colonization was 55 (84.65). From the subjects with bacterial colonization we found Gram negative 36 (55.4%). The most types of bacterials were Pseudomonas Aeroginosa with 16 patients (24.65) and Klebsiella Pneumonia in 12 patients (18.5%). Mean IL-8 serum levels 187.5±68.3. IL-8 serum levels were found highest in subjects who had bacterial colonization 9197.7 ± 68.5; p0.05). Discussion: In this research, there was a significant correlation between colonization of Gram-negative bacteria with high IL-8 serum levels. These results are consistent with several studies which report that bacterial colonization is associated with an increased IL-8 serum levels and correlates with deterioration in pulmonary function and severity of COPD.

Oropharyngeal colonization: epidemiology, treatment and ventilator-associated pneumonia prevention.

Oropharyngeal (OP) colonization and ventilator-associated pneumonia (VAP) mechanisms are tightly linked. A significant within-population variation in OP colonization has been described, with its composition being dependent from patients' severity. For instance, healthy subjects have a very low rate in Gram-negative bacteria (GNB) colonization, while its rate rises in comorbid patients, reaching high proportions in ICU patients. Various factors can be put forward to explain the modifications of hospital acquired OP. ICU patients might suffer from underlying diseases; the gastric reflux induced by the presence of nasogastric tubes and the patients' position influences OP colonization; salivary composition might influence OP content, as it modulates bacterial adhesion and induces reversible bacterial changes enhancing bacterial binding. The transition from OP colonization to VAP has been shown in numerous studies, with the digestive tract acting as a filter, or as a reservoir. Some therapies have been investigated to modulate OP colonization, in order to reduce the risk for VAP. Among those, mammalian antimicrobial peptides have been shown effective in reducing GNB colonization in healthy subjects, but failed in preventing VAP in ICU patients. The widely used chlorhexidine was tested in numerous trials. Data on its efficacy are conflicting, and meta-analyses yield discordant results. Above all, several drawbacks have aroused: a poor tolerance of concentrated solutions; an increased risk of death in the less severe patients; and a reduced susceptibility towards chlorhexidine of number of VAP pathogens. Proanthocyanidins, used to prevent Escherichia coli adhesion to the urothelium, have been tested in mice model of pneumonia with interesting results. Some complementary data are needed before moving to clinical research. Future research paths should include a reappraisal of OP colonization; finding better formulations for chlorhexidine; define the best populations to target oral decontamination and developing other strategies to prevent and treat OP colonization.

Ciprofloxacin prophylaxis during autologous stem cell transplantation for multiple myeloma in patients with a high rate of fluoroquinolone-resistant gram-negative bacteria colonization.

Ciprofloxacin prophylaxis used to be a standard precaution during autologous stem cell transplantation. Its benefit, with a high prevalence of fluoroqinolone resistance in the population, has recently been under scrutiny. To evaluate the impact of cessation of ciprofloxacin prophylaxis during stem cell transplantation for multiple myeloma. Data from 104 patients with multiple myeloma transplanted during the period from January 2013 to April 2015 were retrospectively reviewed. 67 received standard ciprofloxacin prophylaxis (group A) and 37 received no antibacterial prophylaxis (group B). Febrile episodes during neutropenia, bloodstream infection (BSI) and mortality in these two cohorts were evaluated. Gram negative BSI was assessed for the colonization of quinolone-resistant gram-negative pathogens. Secondary Clostridium difficile enterocolitis presence was determined in both cohorts. There were 42 (63%), 7 (10%), and 0 febrile episodes, BSI and gram-negative BSI respectively in group A, and 34 (92%), 12 (32%), and 4 (11%) respectively in group B. The differences in the number of febrile episodes (P=0.0011) and deaths (P=0.0427) were statistically significance. Mortality was 0 and 3 (8%) in group A and group B, respectively. There was no significant difference in colonization with quinolone-resistant gram negative pathogens (25 (37%) versus 11 (30%)) between groups. The occurrence of Clostridium difficile colitis was the same in both groups. We resumed ciprofloxacin prophylaxis for the following reasons. There was a significant reduction in febrile episodes, and consequently a sparing effect of antibiotics used for treatment of this condition. No difference in Clostridium difficile colitis occurred and the mortality rate of 8% in group B was unacceptably high.

Risk for subsequent infection and mortality after hospitalization among patients with multidrug-resistant gram-negative bacteria colonization or infection

BackgroundRisks for subsequent multidrug-resistant gram-negative bacteria (MDRGNB) infection and long-term outcome after hospitalization among patients with MDRGNB colonization remain unknown.MethodsThis observational study enrolled 817 patients who were hospitalized in the study hospital in 2009. We defined MDRGNB as a GNB resistant to at least three different antimicrobial classes. Patients were classified into MDRGNB culture-positive (MDRGNB-CP; 125 patients) and culture-negative (MDRGNB-CN; 692 patients) groups based on the presence or absence of any MDRGNB identified from either active surveillance or clinical cultures during index hospitalization. Subsequent MDRGNB infection and mortality within 12 months after index hospitalization were recorded. We determined the frequency and risk factors for subsequent MDRGNB infection and mortality associated with previous MDRGNB culture status.ResultsIn total, 129 patients had at least one subsequent MDRGNB infection (MDRGNB-CP, 48.0%; MDRGNB-CN, 10.0%), and 148 patients died (MDRGNB-CP, 31.2%; MDRGNB-CN, 15.9%) during the follow-up period. MDR Escherichia coli and Acinetobacter baumannii were the predominant colonization microorganisms; patients with Proteus mirabilis and Pseudomonas aeruginosa had the highest hazard risk for developing subsequent infection. After controlling for other confounders, MDRGNB-CP during hospitalization independently predicted subsequent MDRGNB infection (hazard ratio [HR], 5.35; 95% confidence interval [CI], 3.72–7.71), all-cause mortality (HR, 2.42; 95% CI, 1.67–3.50), and subsequent MDRGNB infection-associated mortality (HR, 4.88; 95% CI, 2.79–8.52) after hospitalization.ConclusionsHarboring MDRGNB significantly increases patients’ risk for subsequent MDRGNB infection and mortality after hospitalization, justifying the urgent need for developing effective strategies to prevent and eradicate MDRGNB colonization.

Does the Gram-negative Bacteria Colonization Impact on the Risk of Develop Infection by Those Organisms During Neutropenia?

Does the Gram-negative Bacteria Colonization Impact on the Risk of Develop Infection by Those Organisms During Neutropenia?

Effects of Methicillin-Resistant Staphylococcus aureus/Multiresistant Gram-Negative Bacteria Colonization or Infection and Isolation Measures in End of Life on Family Caregivers: Results of a Qualitative Study.

Little is known about the experiences of family caregivers of hospitalized patients with confirmed methicillin-resistant Staphylococcus aureus/multiresistant gram-negative bacteria (MRSA/MRGN) diagnosis at the end of life. The study at hand is a subproject of an interdisciplinary cooperation project that aims at developing a patient-, family-, and team-centered approach in dealing with MRSA/MRGN-positive hospitalized patients in palliative and geriatric care. The present study aimed to assess the individual effects of the patient's MRSA/MRGN colonization or infection and isolation measures on family caregivers. Between April 2014 and September 2015, all known family caregivers associated with an MRSA/MRGN-positive patient from a palliative care unit, a hospital palliative care support team, and a geriatric ward were considered for study participation. A qualitative interview study with family caregivers and an additional focus group was conducted. Data were analyzed using the principles of Grounded Theory. Family caregivers (N = 62) raised suggestions regarding the provision of information and communication on the MRSA/MRGN diagnosis and hygiene measures from staff members and the consistency of hygiene procedures. Family caregivers requested not to be stigmatized or being disadvantaged due to the MRSA/MRGN diagnosis of the patient, and they wished to receive psychosocial and emotional support. Staff members and institutional stakeholders should be aware that family caregivers might be burdened and upset by positive MRSA/MRGN diagnosis and the required hygiene measures. The need for detailed and understandable information on MRSA/MRGN, adequate communication between staff members and family caregivers, and support for family caregivers should be of special attention in particular in end-of-life care.

Abnormal vaginal colonization by gram-negative bacteria is significantly higher in pregnancy conceived through infertility treatment compared to natural pregnancy

Objective: To compare abnormal vaginal colonization between natural pregnancy and pregnancy by infertility treatment in high-risk parturient women and to examine the association between abnormal vaginal colonization and early-onset neonatal sepsis (EONS).Methods: The clinical characteristics, vaginal culture result, and delivery outcome of patients who admitted to our high-risk unit between 2005 and 2014 were retrospectively reviewed and compared. We investigated the prevalence of EONS according to maternal vaginal colonization and examined the concordance between maternal vaginal bacteria and etiologic microorganism causing EONS.Results: Among 1096 pregnancies, the rate of vaginal colonization by gram-negative bacteria, especially Escherichia coli was significantly higher in pregnancies by infertility treatment after adjustment of confounding variables (E. coli, OR [95% CI]: 2.47 [1.33–4.57], p = 0.004). The rate of EONS was significantly higher in neonates with maternal abnormal vaginal bacteria colonization (OR [95% CI]: 3.38 [1.44–7.93], p = 0.005) after adjusting for confounding variables. Notably, among microorganisms isolated from maternal vagina, E. coli and Staphylococcus aureus were consistent with the results from neonatal blood culture in EONS.Conclusions: Our data implicate a possible association between gram-negative bacteria colonization and infertility treatment and suggest that maternal vaginal colonization may be associated with EONS of neonates in high-risk pregnancy.

What is new in selective decontamination of the digestive tract?

What is new in selective decontamination of the digestive tract?

The role of systemic antibiotics in acquiring respiratory tract colonization with gram-negative bacteria in intensive care patients: a nested cohort study.

Colonization of the respiratory tract with Gram-negative bacteria in intensive care patients increases the risk of subsequent infections. Application of systemic antibiotics may prevent colonization with Gram-negative bacteria, but this effect has never been quantified. The objective of this study was to determine associations between systemic antibiotic use and acquisition of respiratory tract colonization with Gram-negative bacteria in ICUs. A nested cohort study. A university hospital and a teaching hospital. Patients with ICU stay of more than 48 hours and absence of respiratory tract colonization with Gram-negative bacteria on ICU admission. None. Acquisition was determined through protocolized surveillance. Associations were investigated with Cox regression models with antibiotics as a time-dependent covariate. In all, 250 of 481 patients (52%) acquired respiratory tract colonization with Gram-negative bacteria after a median of 5 days (interquartile range, 3-8 d) (acquisition rate, 77.1/1,000 patient-days at risk). Antibiotic exposure during ICU admission was present in 78% and 72% of the patients with and without acquired Gram-negative bacteria colonization, respectively. In Kaplan-Meier curve analysis, the median times to acquisition of Gram-negative bacteria were 9 days (95% CI, 7.9-10.1) and 6 days (95% CI, 4.8-7.2) in patients receiving and not receiving antibiotics, respectively. In time varying Cox regression analysis, however, the association between acquired colonization and systemic antibiotics was not statistically significant (hazard ratio, 0.90; 95% CI, 0.70-1.16). Among patients not colonized with Gram-negative bacteria in the respiratory tract at admission to ICU, systemic antibiotics during ICU stay were not associated with a reduction in acquisition of Gram-negative bacteria carriage in the respiratory tract during the ICU stay.

Multidrug-resistant gram-negative bacteria colonization of healthy US military personnel in the US and Afghanistan

BackgroundThe US military has seen steady increases in multidrug-resistant (MDR) gram-negative bacteria (GNB) infections in casualties from Iraq and Afghanistan. This study evaluates the prevalence of MDR GNB colonization in US military personnel.MethodsGNB colonization surveillance of healthy, asymptomatic military personnel (101 in the US and 100 in Afghanistan) was performed by swabbing 7 anatomical sites. US-based personnel had received no antibiotics within 30 days of specimen collection, and Afghanistan-based personnel were receiving doxycycline for malaria chemoprophylaxis at time of specimen collection. Isolates underwent genotypic and phenotypic characterization.ResultsThe only colonizing MDR GNB recovered in both populations was Escherichia coli (p=0.01), which was seen in 2% of US-based personnel (all perirectal) and 11% of Afghanistan-based personnel (10 perirectal, 1 foot+groin). Individuals with higher off-base exposures in Afghanistan did not show a difference in overall GNB colonization or MDR E. coli colonization, compared with those with limited off-base exposures.ConclusionHealthy US- and Afghanistan-based military personnel have community onset-MDR E. coli colonization, with Afghanistan-based personnel showing a 5.5-fold higher prevalence. The association of doxycycline prophylaxis or other exposures with antimicrobial resistance and increased rates of MDR E. coli colonization needs further evaluation.