Multidrug Resistant Bacteria Bacteria Research Articles

Multidrug resistant bacteria in critically ill patients: a step further antibiotic therapy

Infections by multidrug resistant bacteria (MDR) occur frequently in patients admitted to intensive care unit (ICU) with incidence up to 40% in many world regions and are usually associated to high mortality. In ICU patients, numerous independent risk factors for infections by MDR bacteria have been identified whose careful management associated to an appropriate use of antibiotics are fundamental. Despite the latter may results challenging in many cases, combination of old and novel antibiotics usually permits to provide an in vitro effective strategy also in the more resistant strains. Nevertheless, as such antibiotic pressure produces harmful effects on microenvironment and immune response that render ICU patients prone to secondary or breakthrough infections by opportunistic agent. Beyond extensive antibiotic therapy, other factors as older age, chronic pathologies, trauma, surgery and persistent infections may cause ICU acquired immune suppression that involves both innate and adaptive immunity. Therefore, the approach to critically ill patients with sepsis caused by MDR infections should be based not only on the research for the best antibiotic strategy but also on the assessment and treatment of immune-dysfunction. Numerous promising immune-modulating therapy are under evaluation and we hope available in the close future.

Antimicrobial prescribing in long-term care facilities: a nationwide point-prevalence study, Slovenia, 2016.

Residents in long-term care are at high risk of infections because of their old age and many related health problems that lead to frequent antibiotic prescribing. The aim of the study was to assess antibiotic use in Slovenian long-term care facilities (LTCFs). The point-prevalence study was conducted between April and June 2016. Online questionnaires were sent to all Slovenian LTCFs. Eighty (68.4%) of the 117 LTCFs contacted, caring for 13,032 residents (70.6% of all Slovenian LTCF residents), responded to the survey. On the day of the study, the mean antibiotic prevalence per LTCF was 2.4% (95% confidence interval: 1.94–2.66). Most (70.2%) of the residents taking antibiotics were female. Most residents were being treated for respiratory tract (42.7%) or urinary tract (33.3%) infections. Co-amoxiclav and fluoroquinolones were the most frequently prescribed antibiotics (41.0% and 22.3% respectively). Microbiological tests were performed for 5.2% of residents receiving antibiotics. Forty nine (19.8%) residents receiving antibiotics were colonised with multidrug-resistant bacteria (MDR). Antibiotic use in Slovenian LTCFs is not very high, but most prescribed antibiotics are broad-spectrum. Together with low use of microbiological testing and high prevalence of colonisation with MDR bacteria the situation is worrisome and warrants the introduction of antimicrobial stewardship interventions.

High Prevalence of Antimicrobial Resistance among Gram Negative Bacteria Isolated from Poultry

Background: Multidrug resistant bacteria (MDR), such as Escherichia coli and Salmonella spp. are threat to the human health care system. In recent years, these MDR bacteria have been found increasingly inside and outside the hospital environment. Food animals (meat and poultry) are increasingly colonized with MDR bacteria, thus posing an additional concern. This study is intended to determine susceptibility and resistance pattern of pathogenic Gram negative bacteria isolated from rectal swabs of chicken against 16 antibiotics.
 Methods: A total of 216 cloacal swab samples (Gaza strip poultry farms) and 87 frozen and fresh meat samples (from slaughter houses and retails) from June 2017 to June 2018 were collected. Isolation and identification of organisms were achieved using standard bacteriological techniques. Antimicrobial susceptibility test was performed according to standard protocols.
 Results: 360 Enterobacteriaceae isolates, and 56 Gram-negative non fermenter were recovered. The predominant Enterobacteriaceae isolate was Citrobacter spp. (22.6%), followed by Enterobacter spp. (17.6%) and E. coli (16.5%). High rates of resistance against Ampicillin (85.4%) and Trimethoprim/ Sulfamethoxazole (80.1%) followed by Chloramphenicol (74%) were recorded. Six samples were positive for Salmonella spp. and Shigella spp. Of the tested Enterobacteriacae isolates, 94.7% were multidrug resistant (MDR), and 31.4% of None fermenting bacilli (NFB) were MDR. Carbapenem resistance was found to be high among isolates; 51.9% for imipenem and 1.8% for meropenem.
 Conclusion: Isolated bacteria in the study area were MDR and this suggests that chickens may be important reservoir of antimicrobial resistant organisms which is a major public health concern.
 

Carriage of multi-drug resistant bacteria among foreigners seeking medical care

Medical tourism has a potential of spreading multi-drug resistant bacteria (MDR). The Hadassah Medical Center serves as a referral center for global medical tourists and for Palestinian Authority residents. In order to assess whether patients of these groups are more likely to harbor MDR bacteria than local residents, we reviewed data from all patients admitted to our institution between 2009 and 2014. We compared MDR rates between countries of residency, controlling for gender, age, previous hospitalization and time from admission to MDR detection. Overall, among 111,577 patients with at least one microbiological specimen taken during hospitalization, there were 3,985 (3.5%) patients with at least one MDR-positive culture. Compared to Israeli patients, tourists and patients from the Palestinian Authority had increased rates of MDR positivity (OR, 95%CI): 2.3 (1.6 to 2.3) and 8.0 (6.3 to 10.1), respectively. Our data show that foreign patients seeking advanced medical care are more likely to carry MDR bacteria than the resident population. Strategies to minimize MDR spread, such as pre-admission screening or pre-emptive isolation should be considered in this population.

Bloodstream infections in cancer patients. Risk factors associated with mortality

ObjectiveThe aim of this study was to evaluate the clinical characteristics and risk factors associated with mortality in cancer patients with bloodstream infections (BSI), analyzing multidrug resistant bacteria (MDR). MethodsWe conducted a prospective observational study at a cancer referral center from August 2016 to July 2017, which included all BSI. Results4220 patients were tested with blood cultures; 496 were included. Mean age was 48 years. In 299 patients with solid tumors, secondary BSI and Central Line-Associated BSI (CLABSI) were the most common (55.9% and 31.8%, respectively). In 197 hematologic patients, primary and mucosal barrier injury (MBI) BSI were the main type (38.6%). Gram-negative were the most frequent bacteria (72.8%), with Escherichia coli occupying the first place (n=210, 42.3%), 48% were Extended-Spectrum Beta-Lactamase (ESBL) producers, and 1.8% were resistant to carbapenems. Mortality at day 30, was 22%, but reached 70% when patients did not receive an appropriate antimicrobial treatment. Multivariate analysis showed that progression or relapse of the oncologic disease, inappropriate antimicrobial treatment, and having resistant bacteria were independently associated with 30-day mortality. ConclusionsEmergence of MDR bacteria is an important healthcare problem worldwide. Patients with BSI, particularly those patients with MDR bacteria have a higher mortality risk.

Non-fermentative Gram-negative rods bacteremia in children with cancer: a 14-year single-center experience.

Data on non-fermentative Gram-negative rods (NFGNR) bacteremia in children with malignancies are limited. The aim of this study was to present clinical picture, antimicrobial susceptibility pattern, risk factors for resistance and outcome in NFGNR bacteremia in children with cancer. All episodes of NFGNR bacteremia occurring during 2001-2014 in children with cancer in a tertiary-care hospital were retrospectively analyzed. Pseudomonas and Acinetobacter spp. resistant to three or more antibiotic classes and all Stenotrophomonas maltophilia (SM) were defined as multidrug-resistant bacteria (MDR). A total of 80 children (44 males, 0.8-18years, median 5years) developed 107 episodes (116 pathogens) of NFGNR bacteremia; Pseudomonas aeruginosa (PA) (51; 43.9%), Acinetobacter baumannii (AB) (21, 18.1%), SM (18, 15.5%); and others (27, 25.2%). The rate of NFGNR bacteremia in children with certain solid tumors (e.g. sarcoma, 12/134 (9.0%)) was comparable to that of hematological malignancies (52/429 (12.2%). Focal infection and septic shock occurred in 16 (14.9%) and four (3.7%) episodes, respectively. Thirty (25.8%) of 116 NFGNR were MDR. The most significant predictors of bacteremia with MDR PA or AB were severe neutropenia (<100 cells/mm3; OR 7.8, p=0.002), hospital-acquired (OR 16.9, p<0.0001) and breakthrough (OR 11.2, p<0.0001) infection. Infection with MDR bacteria was associated with inappropriate empirical therapy. The 30-day mortality was 3/107 (2.8%), all in neutropenic patients with hematological malignancies. NFGNR bacteremia can present with nonspecific signs or symptoms. MDR NFGNRs are common and compromise treatment options, but mortality is relatively low. Knowledge of local epidemiology, pattern and risk factors for resistance is important to guide empirical therapy.

Acquisition of a High Diversity of Bacteria during the Hajj Pilgrimage, Including Acinetobacter baumannii with bla OXA-72 and Escherichia coli with bla NDM-5 Carbapenemase Genes

Pilgrims returning from the Hajj (pilgrimage to Mecca) can be carriers of multidrug-resistant bacteria (MDR). Pharyngeal and rectal swab samples were collected from 98 pilgrims before and after they traveled to the Hajj in 2014 to investigate the acquisition of MDR bacteria. The bacterial diversity in pharyngeal swab samples was assessed by culture with selective media. There was a significantly higher diversity of bacteria in samples collected after the return from the Hajj than in those collected before (P = 0.0008). Surprisingly, Acinetobacter baumannii strains were isolated from 16 pharyngeal swab samples (1 sample taken during the Hajj and 15 samples taken upon return) and 26 post-Hajj rectal swab samples, while none were isolated from samples taken before the Hajj. Testing of all samples by real-time PCR targeting blaOXA-51 gave positive results for only 1% of samples taken during the Hajj, 21/90 (23.3%) pharyngeal swab samples taken post-Hajj, and 35/90 (38.9%) rectal swab samples taken post-Hajj. One strain of A. baumannii isolated from the pharynx was resistant to imipenem and harbored a blaOXA-72 carbapenemase gene. Multilocus sequence typing analysis of 43 A. baumannii isolates revealed a huge diversity of 35 sequence types (STs), among which 18 were novel STs reported for the first time in this study. Moreover, we also found one Escherichia coli isolate, collected from a rectal swab sample from a pilgrim taken after the Hajj, which harbored blaNDM-5, blaCTX-M-15, blaTEM-1, and aadA2 (ST2659 and ST181). In conclusion, pilgrims are at a potential risk of acquiring and transmitting MDR Acinetobacter spp. and carbapenemase-producing Gram-negative bacteria during the Hajj season.

Identification and antimicrobial resistance of members from the Enterobacteriaceae family isolated from canaries (Serinus canaria)

Abstract: The Enterobacteriaceae family contains potentially zoonotic bacteria, and their presence in canaries is often reported, though the current status of these in bird flocks is unknown. Therefore, this study aimed to identify the most common genera of enterobacteria from canaries (Serinus canaria) and their antimicrobial resistance profiles. From February to June of 2013, a total of 387 cloacal swab samples from eight domiciliary breeding locations of Fortaleza city, Brazil, were collected and 58 necropsies were performed in canaries, which belonged to the Laboratory of Ornithological Studies. The samples were submitted to microbiological procedure using buffered peptone water and MacConkey agar. Colonies were selected according to their morphological characteristics on selective agar and submitted for biochemical identification and antimicrobial susceptibility. A total of 61 isolates were obtained, of which 42 were from cloacal swabs and 19 from necropsies. The most isolated bacteria was Escherichia coli with twenty five strains, followed by fourteen Klebsiellaspp., twelve Enterobacterspp., seven Pantoea agglomerans, two Serratiaspp. and one Proteus mirabilis. The antimicrobial to which the strains presented most resistance was sulfonamides with 55.7%, followed by ampicillin with 54.1% and tetracycline with 39.3%. The total of multidrug-resistant bacteria (MDR) was 34 (55.7%). In conclusion, canaries harbor members of the Enterobacteriaceae family and common strains present a high antimicrobial resistance rate, with a high frequency of MDR bacteria.

Risk factors for multidrug resistant bacteria and optimization of empirical antibiotic therapy in postoperative peritonitis

IntroductionThe main objective was to determine risk factors for presence of multidrug resistant bacteria (MDR) in postoperative peritonitis (PP) and optimal empirical antibiotic therapy (EA) among options proposed by Infectious Disease Society of America and the Surgical Infection Society guidelines.MethodsOne hundred patients hospitalised in the intensive care unit (ICU) for PP were reviewed. Clinical and microbiologic data, EA and its adequacy were analysed. The in vitro activities of 9 antibiotics in relation to the cultured bacteria were assessed to propose the most adequate EA among 17 regimens in the largest number of cases.ResultsA total of 269 bacteria was cultured in 100 patients including 41 episodes with MDR. According to logistic regression analysis, the use of broad-spectrum antibiotic between initial intervention and reoperation was the only significant risk factor for emergence of MDR bacteria (odds ratio (OR) = 5.1; 95% confidence interval (CI) = 1.7 - 15; P = 0.0031). Antibiotics providing the best activity rate were imipenem/cilastatin (68%) and piperacillin/tazobactam (53%). The best adequacy for EA was obtained by combinations of imipenem/cilastatin or piperacillin/tazobactam, amikacin and a glycopeptide, with values reaching 99% and 94%, respectively. Imipenem/cilastin was the only single-drug regimen providing an adequacy superior to 80% in the absence of broad spectrum antibiotic between initial surgery and reoperation.ConclusionsInterval antibiotic therapy is associated with the presence of MDR bacteria. Not all regimens proposed by Infectious Disease Society of America and the Surgical Infection Society guidelines for PP can provide an acceptable rate of adequacy. Monotherapy with imipenem/cilastin is suitable for EA only in absence of this risk factor for MDR. For other patients, only antibiotic combinations may achieve high adequacy rates.

Profil bactériologique des bactériémies à germes multirésistants à l'hôpital Charles-Nicolle de Tunis

Objective. – The authors had for aim to evaluate the place of multi-drug resistant bacteria (MDR) in nosocomial bacteremia. Materials and methods. – A retrospective study was carried out at the Microbiology laboratory of Charles Nicolle hospital of Tunis (2001–2003). One hundred and ninety-five isolated MDR [third generation cephalosporin resistant enterobacteria, methicillin–resistant Staphylococcus aureus (MRSA), Acinetobacter baumannii and Pseudomonas aeruginosa resistant to ceftazidime and imipenem]. An automated system was used to detect bloodstream infections. Microorganism identification was performed by conventional methods and antibiotic susceptibilities were determined by the disk diffusion method. Results. – MDR bacteria were resistant to third generation cephalosporins (29%), A. baumannii (24%), P. aeruginosa (24%), and MRSA (10%). ERC 3G were resistant to aminosides and fluorquinolones. A. baumannii and P. aeruginosa had high resistance rates. Associated resistance rates in MRSA were moderate. Conclusion. – MDR bacteria are of great concern in our hospital. This situation emphasizes the importance to maintain rigorous measures of hygiene as well as adapted antibiotic prescriptions.