Intensive care unit-acquired Acinetobacter baumannii infections in a Moroccan teaching hospital: epidemiology, risk factors and outcome

Virulence gene distribution and molecular epidemiological characteristics of carbapenem-resistant Klebsiella pneumoniae in the ICU

OBJECTIVES

The drug-resistant genes carried by carbapenem-resistant Klebsiella pneumoniae (CRKP) limit clinical treatment options, and its virulence genes severely affect patient prognosis. This study aims to investigate the distribution of virulence genes, capsular serotypes, and molecular epidemiological characteristics of CRKP in ICU, to understand the characteristics of CRKP infections in ICU, and to provide a scientific basis for effective monitoring and control of CRKP infections in ICU.

METHODS

A total of 40 non-duplicate strains of CRKP isolated from the ICU of Guangdong Provincial People's Hospital between January 2021 and December 2022 were collected and analyzed. Whole-genome sequencing was used to analyze the distribution of resistance genes, virulence genes, and capsular serotypes of the strains. The sequences of 7 housekeeping genes of CRKP genome were uploaded to the Klebsiella pneumoniae (KPN)multilocus sequence typing (MLST) database to determine the sequence types (STs) of the strains.

RESULTS

The age of the 40 ICU CRKP-infected patients was (69.03±17.82) years old, with various underlying diseases, and there were 20 patients with improved clinical outcome and 20 patients with death. The isolated strains primarily originated from mid-stream urine and bronchoalveolar lavage fluid. Whole-genome sequencing results revealed that the strains predominantly carried blaKPC-1 (29 strains, 72.5%) and blaNDM-1 (6 strains, 15.0%), with 5 strains carrying both blaKPC-1 and blaNDM-1. Various virulence genes were detected, among which the carriage rates of genes such as entA, entB, entE, entS, fepA, fepC, fepG, yag/ecp, and ompA reached 100%, while the carriage rates of genes such as entD, fimB, iroB, iroD, fes,and pla were low. The CRKP strains isolated from ICU were predominantly ST11 (27 cases, 67.5%), with KL64 being the main capsular serotype (29 cases, 72.5%). A total of 23 ST11-KL64 CRKP strains were detected, accounting for 57.5%.

CONCLUSIONS

The main type of ICU CRKP is ST11-KL64, carrying various virulence genes, primarily those related to iron absorption. Furthermore, blaKPC has shifted from blaKPC-2 to blaKPC-1. Therefore, close monitoring of the molecular epidemiological changes of CRKP is necessary, and strict control measures should be implemented to effectively curb the occurrence of CRKP infections.

Carbapenem-resistant Acinetobacter baumannii infections: Antimicrobial resistance patterns and risk factors for acquisition in a Kenyan intensive care unit

Objectives

Multidrug-resistant (MDR) Acinetobacter baumannii (AB), especially carbapenem-resistant (CR) strains, presents a significant challenge in intensive care units (ICUs) but surveillance data in many resource-constrained countries is inadequate. Here, we determined the prevalence of MDRAB and risk factors for infection and mortality in ICU-admitted patients.

Methods

A cross-sectional study among 132 consecutive patients between July 2019 and July 2020, with infected patients followed for 30 days from sample collection to ICU discharge/death. Blood, urine, and tracheal aspirate samples were processed following the standard bacteriological procedures. Isolate identity and antimicrobial susceptibility were elucidated by VITEK 2 Compact system.

Results

The prevalence of MDRAB was 22.7% (30/132), mostly from urine samples (12.1%, 16/132), and dominated by CRAB (83.3%) that were colistin-nonresistant and exhibited high multiple antibiotic resistance indices, ranging from 0.64-0.91. Risk factors for infection were occupation (adjusted odds ratio = 4.41, P = 0.016) and interhospital referral status (adjusted odds ratio = 0.14, P = 0.001). ICU mortality was 20% (6/30).

Conclusion

Our findings underpin the need for strict adherence to and evaluation of infection prevention and control, and continuous surveillance of CRAB in ICU, especially among the risk groups, in the current study setting and beyond.

A novel strategy to characterize the pattern of β-lactam antibiotic-induced drug resistance in Acinetobacter baumannii

Carbapenem-resistant Acinetobacter baumannii (CRAb) is an urgent public health threat, according to the CDC. This pathogen has few treatment options and causes severe nosocomial infections with > 50% fatality rate. Although previous studies have examined the proteome of CRAb, there have been no focused analyses of dynamic changes to β-lactamase expression that may occur due to drug exposure. Here, we present our initial proteomic study of variation in β-lactamase expression that occurs in CRAb with different β-lactam antibiotics. Briefly, drug resistance to Ab (ATCC 19606) was induced by the administration of various classes of β-lactam antibiotics, and the cell-free supernatant was isolated, concentrated, separated by SDS-PAGE, digested with trypsin, and identified by label-free LC-MS-based quantitative proteomics. Thirteen proteins were identified and evaluated using a 1789 sequence database of Ab β-lactamases from UniProt, the majority of which were Class C β-lactamases (≥ 80%). Importantly, different antibiotics, even those of the same class (e.g. penicillin and amoxicillin), induced non-equivalent responses comprising various isoforms of Class C and D serine-β-lactamases, resulting in unique resistomes. These results open the door to a new approach of analyzing and studying the problem of multi-drug resistance in bacteria that rely strongly on β-lactamase expression.

Intermediate Syndrome Due to Organophosphate Poisoning: A Case Report

Organophosphates, also known as phosphate esters, are a category of pesticide compounds that function by indirectly inhibiting the activity of an enzyme called acetylcholinesterase (AChE). AChE is responsible for breaking down acetylcholine (ACh) at the neuromuscular junction into acetic acid and choline. These compounds cause various clinical presentations upon acute toxicity, among which intermediate syndrome (IMS) exhibits an unpredictable course. This report describes the case of a farmer who ingested monocrotophos and ethanol in a suicide attempt, leading to a prolonged stay in the hospital and invasive ventilation, along with complications including ventilator-associated pneumonia. The patient received a total of 9000 mg of atropine over his 14-day hospitalization period.

Genomic Determinants of Pathogenicity and Antimicrobial Resistance of Nosocomial Acinetobacter baumannii Clinical Isolates of Hospitalized Patients (2019-2021) from a Sentinel Hospital in Hangzhou, China

Purpose

Acinetobacter baumannii (A. baumannii or AB) is one of the most opportunistic, nosocomial pathogens threatening public healthcare across countries. A. baumannii has become a primary growing concern due to its exceptional ability to acquire antimicrobial resistance (AMR) to multiple antimicrobial agents which is increasingly reported and more prevalent every year. Therefore, there is an urgent need to evaluate the AMR knowledge of A. baumannii for effective clinical treatment of nosocomial infections. This study aimed to investigate the clinical distribution AMR phenotypes and genotypes, and genomic characteristics of A. baumannii isolates recovered from hospitalized patients of different clinical departments of a sentinel hospital to improve clinical practices.

Methods

A total of 123 clinical isolates were recovered from hospitalized patients of different clinical departments during 2019-2021 to analyze AMR patterns, and further subjected to whole-genome sequencing (WGS) investigations. Multi-locus sequence typing (MLST), as well as the presence of antimicrobial-resistant genes (ARGs), virulence factor genes (VFGs) and insertion sequences (ISs) were also investigated from WGS data.

Results

The results highlighted that A. baumannii clinical isolates had shown a high AMR rate, particularly from the intensive care unit (ICU), towards routinely used antimicrobials, ie, β-lactams and fluoroquinolones. ST2 was the most prevalent ST in the clinical isolates, it was strongly associated to the resistance of cephalosporins and carbapenems, with bla_OXA-23 and bla_OXA-66 being the most frequent determinants; moreover, high carrier rate of VFGs was also observed such as all strains containing the ompA, adeF, pgaC, lpsB, and bfmR genes.

Conclusion

Acinetobacter baumannii clinical isolates are mostly ST2 with high rates of drug resistance and carrier of virulence factors. Therefore, it requires measurements to control its transmission and infection.

Antimicrobial resistance profiles and associated factors of Acinetobacter and Pseudomonas aeruginosa nosocomial infection among patients admitted at Dessie comprehensive specialized Hospital, North-East Ethiopia. A cross-sectional study

Introduction

Hospital admitted patients are at increased risk of nosocomial infections (NIs) with multi-drug resistant (MDR) pathogens which are prevalent in the hospital environment. Pseudomonas aeruginosa (P. aeruginosa) and Acinetobacter baumannii (A. baumannii) are common causes of NIs worldwide. The objective of this study is to determine antimicrobial resistance profiles and associated factors of Acinetobacter spp and P. aeruginosa NIs among hospitalized patients.

Methods

A cross-sectional study was conducted at Dessie comprehensive specialized hospital, North-East Ethiopia, from February 1 to April 30, 2020. A total of 254 patients who were suspected of the bloodstream, urinary tract, or surgical site nosocomial infections were enrolled consecutively. Socio-demographic and other variables of interest were collected using a structured questionnaire. Specimens were collected and processed following standard microbiological procedures. Antimicrobial susceptibility was determined using the Kirby-Bauer disk diffusion method following Clinical and Laboratory Standards Institute guidelines. Data were analyzed with SPSS version 23 and p-value < 0.05 was considered statistically significant.

Results

Overall, 13% of patients had nosocomial Acinetobacter spp and/or P. aeruginosa infections. The culture positivity rate was 16(6.3%) for Acinetobacter spp and 18(7.1%) for P. aeruginosa. Patients admitted in the surgical ward (Adjusted odds ratio (AOR):10.66;95% confidence interval (CI):1.22–93.23), pediatric ward (AOR:14.37;95%CI:1.4–148.5), intensive care unit (AOR:41.93;95%CI:4.7–374.7) and orthopedics (AOR:52.21;95%CI:7.5–365) were significantly at risk to develop NIs compared to patients admitted in the medical ward. Patients who took more than two antimicrobial types at admission were 94% (AOR:0.06; 95% CI:0.004–0.84) times more protected from NIs compared to those who did not take any antimicrobial. About 81% of Acinetobacter spp and 83% of P. aeruginosa isolates were MDR. Amikacin and meropenem showed promising activity against Acinetobacter spp and P. aeruginosa isolates.

Conclusion

The high prevalence of MDR Acinetobacter spp and P. aeruginosa nosocomial isolates enforce treating of patients with NIs based on antimicrobial susceptibility testing results.

Production and characterization of novel monoclonal antibodies against outer membrane protein A (OmpA) of Acinetobacter baumannii

BACKGROUND

Infection caused by Acinetobacter baumannii has emerged as a significant clinical problem with unacceptably high mortality rate due to the increase in antibiotic-resistant strains. Producing novel monoclonal antibody (MAb) against outer membrane protein A (OmpA) could be considered as a potential tool to improve treatment of A. baumannii infections.

OBJECTIVES

In this study, we aimed to produce murine MAbs against OmpA peptide of A. baumannii.

MATERIALS AND METHODS

BALB/c mice were immunized with 18-mer amino acid peptide as a part of the OmpA protein. Four antibody-secreting hybridomas were obtained using hybridoma technology and then characterized according to isotypes, affinity constant, reactivity in ELISA, flow cytometry, indirect immunofluorescence (IFA) and opsonophagocytic killing assays.

RESULTS

All four produced MAbs (1A1-D10, 1G1-E7, 2C11-F10, and 4H2-H9) had IgG1 isotype with Kappa light chain. One of these MAbs, 1G1-E7 was purified and selected for further characterizations. 1G1-E7 showed a high reactivity with both immunogenic peptide and A. baumannii in ELISA. Our results indicated that 1G1-E7 MAb reacted with 95.3% of A. baumannii in flow cytometry as well as IFA. Moreover, the affinity of the 1G1-E7 MAb was measured 1.37 × 10⁸ M^-1. The 1G1-E7 significantly improved opsonophagocytic killing of a clinical isolate of A. baumannii.

CONCLUSION

Our findings showed that the OmpA can be identified by produced MAbs. The efficacy of novel anti-OmpA antibodies in A. baumannii targeting needs to be further investigated in challenging models, and then could be subjected for genetic engineering to produce therapeutic antibody against A. baumannii.

Effect of Nurse-Led Goal-Directed Lung Physical Therapy on the Prognosis of Pneumonia in Sepsis Patients in the ICU: A Prospective Cohort Study

BACKGROUND

Pneumonia poses a significant burden on healthcare systems. However, few studies have focused on nurse-led goal-directed lung physical therapy (GDLPT) for pneumonia in sepsis patients in the intensive care unit (ICU).

OBJECTIVES

This study aimed to investigate the effects of nurse-led GDLPT on the prognosis of pneumonia in sepsis patients in the ICU.

METHODS

We performed a prospective 2-phase (before-and-after) study over 3 years. After an observational phase (phase 1, n = 188), we designed, implemented, and evaluated a nurse-led GDLPT protocol (phase 2, n = 359) for pneumonia in sepsis patients in the ICU. The primary outcome was 28-day mortality.

RESULTS

We evaluated 742 critically ill patients with sepsis from January 2017 to January 2020. Among the 742 sepsis patients, 609 were diagnosed with pneumonia and 547 who met the inclusion criteria were enrolled in the study. Compared with patients in phase 1, patients in phase 2 had significantly shorter mechanical ventilation duration (5 [4, 6] days vs. 5 [4, 8] days, p = 0.037), shorter ICU stay (9 [4, 16] days vs. 9 [6, 20] days, p = 0.010), lower ICU mortality (15.0% [54/359] vs. 25.5% [48/188], p = 0.003), and lower 28-day mortality (16.7% [60/359] vs. 27.1% ([51/188], p = 0.004). Multivariate logistic regression analysis revealed that nurse-led GDLPT (odds ratio 0.540, 95% confidence interval 0.345-0.846, p = 0.007), clinical pulmonary infection score (odds ratio 1.111, 95% confidence interval 1.012-1.221, p = 0.028), and ventilation day (OR 1.160, 95% CI, 1.058-1.240, p<0.001)were independent predictors of 28-day mortality for pneumonia in sepsis patients, and that nurse-led GDLPT was a protective factor.

CONCLUSIONS

Nurse-led GDLPT improved the outcomes of pneumonia in sepsis patients, and was particularly associated with shortened mechanical ventilation duration and ICU stay, and reduced ICU mortality and 28-day mortality.

Molecular Epidemiology of Acinetobacter calcoaceticus-Acinetobacter baumannii Complex Isolated From Children at the Hospital Infantil de México Federico Gómez

The Acinetobacter calcoaceticus-baumannii (Acb) complex is regarded as a group of phenotypically indistinguishable opportunistic pathogens responsible for mainly causing hospital-acquired pneumonia and bacteremia. The aim of this study was to determine the frequency of isolation of the species that constitute the Acb complex, as well as their susceptibility to antibiotics, and their distribution at the Hospital Infantil de Mexico Federico Gomez (HIMFG). A total of 88 strains previously identified by Vitek 2®, 40 as Acinetobacter baumannii and 48 as Acb complex were isolated from 52 children from 07, January 2015 to 28, September 2017. A. baumannii accounted for 89.77% (79/88) of the strains; Acinetobacter pittii, 6.82% (6/88); and Acinetobacter nosocomialis, 3.40% (3/88). Most strains were recovered mainly from patients in the intensive care unit (ICU) and emergency wards. Blood cultures (BC) provided 44.32% (39/88) of strains. The 13.63% (12/88) of strains were associated with primary bacteremia, 3.4% (3/88) with secondary bacteremia, and 2.3% (2/88) with pneumonia. In addition, 44.32% (39/88) were multidrug-resistant (MDR) strains and, 11.36% (10/88) were extensively drug-resistant (XDR). All strains amplified the bla_OXA-51 gene; 51.13% (45/88), the bla_OXA-23 gene; 4.54% (4/88), the bla_OXA-24 gene; and 2.27% (2/88), the bla_OXA-58 gene. Plasmid profiles showed that the strains had 1–6 plasmids. The strains were distributed in 52 pulsotypes, and 24 showed identical restriction patterns, with a correlation coefficient of 1.0. Notably, some strains with the same pulsotype were isolated from different patients, wards, or years, suggesting the persistence of more than one clone. Twenty-seven sequence types (STs) were determined for the strains based on a Pasteur multilocus sequence typing (MLST) scheme using massive sequencing; the most prevalent was ST 156 (27.27%, 24/88). The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas I-Fb system provided amplification in A. baumannii and A. pittii strains (22.73%, 20/88). This study identified an increased number of MDR strains and the relationship among strains through molecular typing. The data suggest that more than one strain could be causing an infection in some patient. The implementation of molecular epidemiology allowed the characterization of a set of strains and identification of different attributes associated with its distribution in a specific environment.

Rapid Killing and Biofilm Inhibition of Multidrug-Resistant Acinetobacter baumannii Strains and Other Microbes by Iodoindoles

Multi-drug resistant Acinetobacter baumannii is well-known for its rapid acclimatization in hospital environments. The ability of the bacterium to endure desiccation and starvation on dry surfaces for up to a month results in outbreaks of health care-associated infections. Previously, indole and its derivatives were shown to inhibit other persistent bacteria. We found that among 16 halogenated indoles, 5-iodoindole swiftly inhibited A. baumannii growth, constrained biofilm formation and motility, and killed the bacterium as effectively as commercial antibiotics such as ciprofloxacin, colistin, and gentamicin. 5-Iodoindole treatment was found to induce reactive oxygen species, resulting in loss of plasma membrane integrity and cell shrinkage. In addition, 5-iodoindole rapidly killed three Escherichia coli strains, Staphylococcus aureus, and the fungus Candida albicans, but did not inhibit the growth of Pseudomonas aeruginosa. This study indicates the mechanism responsible for the activities of 5-iodoindole warrants additional study to further characterize its bactericidal effects on antibiotic-resistant A. baumannii and other microbes.

High Frequency of AdeA, AdeB and AdeC Genes among Acinetobacter baumannii Isolates

BACKGROUND

Efflux pumps are involved in resistance of Acinetobacter baumannii isolates to antimicrobial agents. AdeABC efflux pump is one of the RND superfamily efflux pump and consists of adeA (membrane fusion), adeB (multidrug transporter) and adeC (outer membrane) genes. In this study, the frequency of adeA, adeB and adeC genes among A. baumannii isolates with resistance to erythromycin, trimethoprim, meropenem and imipenem was investigated.

METHODS

Overall, 79 strains of A. baumannii were isolated from patients admitted to two major hospitals in Tehran during 2016. Antibiotic susceptibility testing was determined by disc diffusion and microdilution methods according to Clinical and Laboratory Standards Institute (CLSI) guideline. The presence of adeA, adeB and adeC genes was also determined using Multiplex PCR assay.

RESULTS

The highest and the lowest resistance among A. baumannii isolates were to trimethoprim (93%) and erythromycin (53%), respectively. The frequency of adeA, adeB and adeC genes was 96.2%, 96.2% and 91.1 % respectively. There was a significant relationship between imipenem resistance and presence of efflux pump genes (P<0.05).

CONCLUSION

According to the high prevalence of the AdeABC efflux system genes, it may involve in resistance of clinical isolates of A. baumannii to imipenem, especially.

The epidemiology of carbapenem-non-susceptible Acinetobacter species in Europe: analysis of EARS-Net data from 2013 to 2017

BACKGROUND

Due to limited therapeutic options and their association with high mortality and morbidity, carbapenem-non-susceptible Acinetobacter spp. (CNA) are of significant public health importance. This study aimed to describe current epidemiological trends of CNA proportions in Europe and to identify factors that are associated with carbapenem non-susceptibility of isolates from patients with invasive Acinetobacter spp. infections.

METHODS

Data from routine carbapenem susceptibility testing of 18,412 invasive clinical Acinetobacter spp. isolates from 30 European countries in 2013-2017 were analysed using descriptive statistical analyses and uni- and multivariable regression analyses. These data were obtained from the European Antimicrobial Resistance Surveillance Network (EARS-Net).

RESULTS

The population-weighted mean proportion of carbapenem-non-susceptible Acinetobacter spp. in Europe is 35.6% (95% confidence interval [CI] 29.7-42.0%). With CNA proportions of 75.5% (95% CI 71.2-79.4%) and 71.5% (95% CI 66.7-75.9%) the burden of CNA is particularly high in Southern and Eastern European regions. In contrast, Northern and Western European regions recorded CNA proportions of 2.8% (95% CI 1.2-6.0%) and 6.3% (95% CI 4.5-8.9%), respectively. Population-weighted mean CNA proportions are especially high in Acinetobacter spp. isolates from intensive care units (54.0% [95% CI 47.6-60.3%]). Male gender, age above 20 years and ICU admission were identified as independent factors associated with an increased likelihood of CNA.

CONCLUSION

The burden of carbapenem-non-susceptible Acinetobacter spp. is particularly high in Southern and Eastern Europe. There is a risk that resistance could spread to other parts of Europe. Therefore, increased efforts in infection control and antibiotic stewardship, particularly in Intensive Care Units, are necessary to combat the spread of CNA in Europe.

The incidence and prevalence of hospital-acquired (carbapenem-resistant) Acinetobacter baumannii in Europe, Eastern Mediterranean and Africa: a systematic review and meta-analysis

Due to therapeutic challenges, hospital-acquired infections (HAIs) caused by Acinetobacter baumannii (HA-AB), particularly carbapenem-resistant strains (HA-CRAB) pose a serious health threat to patients worldwide. This systematic review sought to summarize recent data on the incidence and prevalence of HA-AB and HA-CRAB infections in the WHO-defined regions of Europe (EUR), Eastern Mediterranean (EMR) and Africa (AFR). A comprehensive literature search was performed using MEDLINE, EMBASE and GMI databases (01/2014-02/2019). Random-effects meta-analyses were performed to determine the pooled incidence of HA-AB and HA-CRAB infections as well as the proportions of A. baumannii among all HAIs. 24 studies from 3,340 records were included in this review (EUR: 16, EMR: 6, AFR: 2). The pooled estimates of incidence and incidence density of HA-AB infection in intensive care units (ICUs) were 56.5 (95% CI 33.9-92.8) cases per 1,000 patients and 4.4 (95% CI 2.9-6.6) cases per 1,000 patient days, respectively. Five studies conducted at a hospital-wide level or in specialized clinical departments/wards (ICU + non-ICU patients) showed HA-AB incidences between 0.85 and 5.6 cases per 1,000 patients. For carbapenem-resistant A. baumannii infections in ICUs, the pooled incidence and incidence density were 41.7 (95% CI 21.6-78.7) cases per 1,000 patients and 2.1 (95% CI 1.2-3.7) cases per 1,000 patient days, respectively. In ICUs, A. baumannii and carbapenem-resistant A. baumannii strains accounted for 20.9% (95% CI 16.5-26.2%) and 13.6% (95% CI 9.7-18.7%) of all HAIs, respectively. Our study highlights the persistent clinical significance of hospital-acquired A. baumannii infections in the studied WHO regions, particularly in ICUs.

Nosocomial Acinetobacter baumannii infection in children in adult versus pediatric intensive care units

BACKGROUND

We hypothesized that children treated in adult intensive care units (ICUs) might be at increased risk of hospital-acquired infection. We therefore compared the incidence of Acinetobacter baumannii infection in children treated in pediatric ICUs (PICUs) and in those treated in adult ICUs.

METHODS

Patients aged <18 years admitted to PICUs or adult ICUs between March 2009 and June 2017 were enrolled. We retrospectively investigated A. baumannii isolates and calculated the A. baumannii incidence during ICU admission. Cox regression was used to identify possible risk factors for A. baumannii infection.

RESULTS

Eight hundred and thirty ICU cases were included; 508 were treated in PICUs ("PICU group") and 322 in adult ICUs ("adult-ICU group"). Acinetobacter baumannii was isolated 19 (3.7%) and 23 (7.1%) times in the PICU and adult-ICU groups, respectively. Incidence densities for A. baumannii acquisition in PICU and adult-ICU groups were 1.63 and 5.62 per 1,000 ICU days, respectively. In the Cox regression model, the hazard ratio for A. baumannii acquisition associated with treatment in PICUs was 0.33 (95% confidence interval: 0.17-0.61; P = 0.001). In multivariate analysis after adjusting for age and sex, treatment in PICU remained significantly associated with a reduced risk of A. baumannii infection (hazard ratio: 0.40; 95%; confidence interval: 0.20-0.76).

CONCLUSIONS

Pediatric patients treated in a PICU had a lower rate and incidence density of A. baumannii nosocomial infection than those treated in adult ICUs, suggesting that PICUs provide better infection control for children than adult ICUs.

Risk factors and clinical outcomes for intensive care unit patients with mul-tidrug-resistant Acinetobacter spp. bacteremia

BACKGROUND

Multidrug-resistant (MDR) isolates of Acinetobacter spp. have been reported worldwide. This study aimed to analyze clinical features and outcomes of intensive care unit (ICU) patients with MDR Acinetobacter spp. bacteremia and to determine factors influencing survival by using 30-day mortality as the primary endpoint.

METHODS

A case-control study included a total of 164 patients with MDR Acinetobacter spp. bacteremia hospitalized in ICUs in Vojvodina Province, Serbia, from January 2013 through March 2016. Medical records were reviewed, and patients' demographic and clinical characteristics were collected. Predictors of 30-day mortality were identified by logistic regression analysis.  Results: The overall 30-day mortality rate was 48.2 % (79 of 164 patients). Multivariate logistic regression analysis revealed that independent predictors of 30-day mortality were two or more co-morbidities, diabetes mellitus, and inappropriate use of antimicrobials.  Conclusion: Early implementation of appropriate antimicrobial therapy, particularly in critically ill ICU patients with MDR Acinetobacter spp. bacteremia, with two or more co-morbidities and diabetes mellitus, can be crucial for survival. HIPPOKRATIA 2020, 24(1): 21-26.

Molecular epidemiology and genetic characterisation of carbapenem-resistant Acinetobacter baumannii isolates from Guangdong Province, South China

OBJECTIVES

Carbapenem-resistant Acinetobacter baumannii (CRAB) has become a worldwide issue. This study aimed to characterise the epidemiology and genetic relationships of A. baumannii isolates in Guangdong Province, China.

METHODS

CRAB isolates were collected from five municipal hospitals from June-December 2017. The 16S-23S rRNA intergenic spacer region was used for confirmation of strain identity. Antimicrobial susceptibility testing and the CarbAcineto NP test were performed to analyse the resistance spectrum and carbapenemase production of the isolates. PCR-based assays were used to detect β-lactamase genes and related mobile genetic elements. Genetic diversity among the isolates was analysed by enterobacterial repetitive intergenic consensus (ERIC)-PCR, multilocus sequence typing (MLST) and multiplex PCR.

RESULTS

A total of 122 isolates were confirmed as A. baumannii; all were resistant to the tested antibiotics except for tigecycline and colistin. The CarbAcineto NP test showed that 93.4% of the isolates produced a carbapenemase. bla_OXA-23-like and extended-spectrum β-lactamase-encoding genes were found by PCR in 94.3% and 91.8% of the isolates, respectively. Furthermore, the genetic environment of bla_OXA-23-like was mainly associated with transposons Tn2008 (46.1%), Tn2006 (27.0%) and Tn2009 (20.9%). MLST identified six existing sequence types (STs) and three novel STs, of which ST195 (35.7%) and ST208 (32.1%) were the most common, belonging to clonal group 92 and European clone II.

CONCLUSION

This study suggests that co-production of β-lactamases was the major resistance mechanism of CRAB isolates. Dissemination of bla_OXA-23-like may be facilitated by transposable elements. ST195 and ST208 were the predominant epidemic types of A. baumannii in Guangdong Province.