Recently, emergence of carbapenem-resistance, in particular due to
Klebsiella pneumoniae
carbapenemase (KPC), was observed among
K
.
pneumoniae
causing urinary tract infections in Croatia. The aim of ...the study was to characterize, antimicrobial susceptibility, carbapenem resistance, virulence traits and plasmid types of the urinary KPC positive isolates of
K. pneumoniae
. The antimicrobial susceptibility to a wide range of antibiotics was determined by broth microdilution method. The transferability of meropenem resistance was determined by conjugation (broth mating method) employing
Escherichia coli
J63 strain resistant to sodium azide. Genes encoding broad and extended-spectrum β-lactamases, plasmid-mediated AmpC β-lactamases, group A and B carbapenemases, and carbapenem hydrolyzing oxacillinases (bla
OXA-48like
), respectively, were determined by Polymerase chain reaction (PCR). In total 30 KPC-positive
K
.
pneumoniae
urinary isolates collected from different regions of Croatia were analysed. The isolates were uniformly resistant to all tested antibiotics except for variable susceptibility to gentamicin, sulphamethoxazole/trimethoprim, and colistin, respectively. Four isolates were resistant to colistin with MICs values ranging from 4 to 16 mg/L. All tested isolates were susceptible to ceftazidime/avibactam. Sixteen isolates transferred meropenem resistance to
E. coli
recipient strain by conjugation. Other resistance markers were not co-transferred. PCR was positive for bla
KPC
and bla
SHV
genes in all isolates whereas 13 isolates tested positive also for bla
TEM
genes. PCR based replicon typing (PBRT) revealed the presence of FIIs in 13 and FIA plasmid in two strains. The study showed dissemination of KPC-producing
K. pneumoniae
in urinary isolates, posing a new epidemiological and treatment challenge. Sulphamethoxazole/trimethoprim, colistin, and ceftazidime/avibactam remain so far, as the therapeutic options.
In addition to RT-PCR assays, serology testing that has been recognized as a useful tool to assess the spread of infection in the population is considered successful and important strategy in the ...control of the global pandemic of SARS-CoV-2 infection. Now, a great number of manufacturers offer their serologic tests on the market. When interpretating the results, the rate of seroprevalence should be taken in consideration because it may influence the positive predictive value, as well as cross-reactivity with other coronaviruses in case of assays with poorly designed antigens. We present results of 11 patients with different clinical background and tested with two different serologic tests, DIAPRO (ELISA; Sesto San Giovanni, Italy) and VIDAS (ELFA; BioMerieux, Marcy I’Etoile, France). The results obtained by the former test showed ten of these patients to be IgG positive and one patient was IgG weakly positive with different confidence index. The latter test discriminated positive results with medium confidence index on the former test as negative. The results obtained with two serology tests were concordant with the observation that the results with medium confidence index may indicate cross-reactivity.
Resistance to carbapenems in
has become a matter of the highest concern in the last decade. Recently,
harboring multiple carbapenemases were detected in three hospital centers in Croatia and in the ...outpatient setting, posing a serious therapeutic challenge for clinicians. In this study, we analyzed eight
and two
complex isolates with multiple carbapenemases, with regard to antibiotic susceptibility, β-lactamase production and plasmid content. The isolates demonstrated uniform resistance to amoxicillin/clavulanate, piperacillin/tazobactam, cefuroxime, ceftazidime, cefotaxime, ceftriaxone and ertapenem. Among novel β-lactam/inhibitor combinations, ceftazidime/avibactam exhibited moderate activity, with 50% of isolates susceptible. All isolates demonstrated resistance to imipenem/cilastatin/relebactam, and all but one to ceftolozane/tazobactam. Four isolates exhibited a multidrug-resistant phenotype (MDR), whereas six were allocated to an extensively drug-resistant phenotype (XDR). OKNV detected three combinations of carbapenemases: OXA-48+NDM (five isolates), OXA-48+VIM (three isolates) and OXA-48+KPC (two isolates). Inter-array testing identified a wide variety of resistance genes for β-lactam antibiotics:
,
,
,
,
,
, aminoglycosides:
6,
,
,
and
, fluoroquinolones:
A,
B and
S, sulphonamides:
1 and
2 and trimethoprim:
.
genes were reported for the first time in Croatia. This study demonstrated the ability of
and
to acquire various resistance determinants under the selection pressure of antibiotics widely used during the COVID-19 pandemic. The novel inter-array method showed good correlation with OKNV and PCR, although some discrepancies were found.
In recent years, a dramatic increase in the prevalence of
Escherichia coli
strains producing extended-spectrum β-lactamases (ESBLs) has been observed — both in the community and in healthcare ...settings. This multicentric study aimed to characterize ESBLs produced by
E. coli
isolates causing hospital-onset and community urinary tract infections, as well as to compare their antimicrobial sensitivity patterns, β-lactamase content and plasmid types. Phenotypic tests for the detection of ESBLs and plasmid-mediated AmpC β-lactamases were initially pursued, followed by molecular detection of resistance genes, plasmid characterization, genotyping with pulsed-field gel electrophoresis and whole genome sequencing (WGS). The isolates exhibited high level of resistance to expanded-spectrum cephalosporins (ESC) and carried CTX-M (cefotaximase-Munich) or TEM (Temoniera) β-lactamases. All six representative isolates subjected to WGS belonged to the widespread clone ST131. In conclusion, our study demonstrated dissemination of group 1 CTX-M positive
E. coli
in different geographic regions of Croatia, but also different components of the health care systems (hospitals, nursing homes and the community) and confirmed the switch from SHV-2 (suphydril variant) and SHV-5 ESBLs to the nation-wide predominance of group 1 CTX-M β-lactamases. Different plasmids were shown to be associated with the dissemination of
bla
CTX-M
genes in different geographic regions of Croatia.
The objective was to compare the efficacy of three different lasers in disinfection of root canals inoculated with Enterococcus faecalis and Candida albicans biofilms.
Endodontic space disinfection ...depends on the type of root canal irrigant used and the way it is delivered and agitated because irrigants have limited ability to reach all parts of root canal system.
Thirty single-rooted human teeth were selected. Root canals were instrumented and root surfaces were sealed using adhesive and the apical openings with adhesive and composite resin. Roots were fixed in Eppendorf tubes and sterilized in autoclave. The specimens were randomly divided into three experimental groups (n = 10) and inoculated with E. faecalis and C. albicans. After 7 days of incubation period, the number of E. faecalis and C. albicans colony-forming units (CFUs) was determined for each root canal. In the first experimental group, Er:YAG laser (0.3 W) with photon-induced photoacoustic streaming technique was used for root canal disinfection, in the second, Nd:YAG laser (1.5 W), and in the third, Er,Cr:YSGG (1.25 W) laser was used. After different root canal disinfection protocols, the number of E. faecalis and C. albicans CFUs was determined again for each root canal.
Er:YAG and Er,Cr:YSGG lasers eradicated significant number of E. faecalis and C. albicans CFUs (p < 0.05), while Nd:YAG laser irradiation did not result in statistically significant reduction (p > 0.05). Er,Cr:YSGG laser eradicated significantly more microorganisms in comparison with Er:YAG laser (p < 0.05).
Er,Cr:YSGG laser was the most efficient tool in eradication of E. faecalis and C. albicans biofilms.
Extended-spectrum β-lactamases (ESBLs) hydrolyse extended-spectrum cephalosporins (ESC) and aztreonam. As ESBL-producing organisms have been identified in food producing animals, the aim of our study ...was to detect and analyse such
isolates from poultry. Antibiotic susceptibility of the isolates was determined with disk-diffusion and broth microdilution methods. ESBLs were detected with the double-disk synergy and inhibitor-based test with clavulanic acid. The transferability of cefotaxime resistance was determined with conjugation experiments, and genes encoding ESBLs, plasmid-mediated AmpC β-lactamases, and quinolone resistance determinants identified by polymerase chain reaction. The study included 108 faecal samples (cloacal swabs) from 25 different poultry farms in the Zenica-Doboj Canton, Bosnia and Herzegovina. Of these, 75 (69.4 %) were positive for
, of which 27 were resistant to cefotaxime, amoxicillin, cefazoline, and cefriaxone, and susceptible to imipenem, meropenem, ertapenem, and amikacin. All 27 cefotaxime-resistant isolates were positive in double-disk synergy and combined disk tests. Eighteen isolates transferred cefotaxime resistance to
recipient. Twenty-one isolates were positive for the
cluster genes and seven for
. Fourteen were positive for the
genes. The most frequent plasmid incompatibility group was IncFIB, whereas IncFIA and Inc HI1 were present in only a few isolates. Two different sequence types (STs) were identified: ST117 and ST155. The emergence of ESBL-producing
in farm animals presents a public health threat, as they can colonise the intestine and cause infections in humans.
Phenotypic detection of metallo-β-lactamases (MBLs) in
is a serious challenge to clinical microbiologists. MBLs are inhibited by metal chelators such as ethylenediaminetetraacetic acid) (EDTA). ...Production of MBLs cannot be recognized based on resistance phenotype. Therefore, phenotypic tests using EDTA are recommended. The aim of this study was to investigate the sensitivity and specificity of inhibitor based tests (EDTA) for detection of MBL. A total of 172
strains (123 carbapenemase positive and 49 carbapenemase negative) were analyzed. Phenotypic detection of MBLs was performed by the combined disk test with EDTA (CDT-EDTA) and EPI-dilution test (EPI-DT). Both tests were positive in all 11 isolates possessing VIM-1 MBL, showing 100% sensitivity. However, false positive results were observed in strains with class D carbapenemases using both tests, i.e. all OXA-23 and OXA-24/40 producing organisms and most OXA-58 positive strains (77% with CDT-EDTA
. 65% with EPI-DT). False positive results can occur because oxacillinases are converted to a less active state in the presence of EDTA, leading to augmentation of the inhibition zone around the carbapenem disk or reduction of carbapenem minimum inhibitory concentrations. This study showed high sensitivity but low specificity of phenotypic methods in the detection of MBLs.
Background
Surgery of the abdominal cavity may lead to postoperative defects to the ventricular segment of the abdominal wall. The reconstruction of these defects, especially in the area of the ...median line, represents an issue during the course of healing due to the role of the abdominal cavity in respiratory processes.
Methods
Reconstructive surgical procedure was performed on an infected vast defect to the ventral segment of the abdominal wall in a 77-year-old woman by a modified “Mercedes closure pattern,” i.e., by combining three fasciocutaneous flaps: bipedicle flap of the upper segment of the abdominal wall and two sliding breast flaps.
Results
Application of a modified complex Mercedes closure pattern was successful and positively affected the redistribution of pressure forces at the places where the edges of the wound were in contact.
Conclusions
The applied and described technique of closing the abdominal cavity decreased the possibility of infection to the prosthetic material, because direct contact between the sutures and the prosthetic no longer existed.
Level of Evidence IV
This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors
www.springer.com/00266
.
Bloodstream infections associated with AmpC-producing Enterobacterales are severe medical conditions which, without prompt and effective treatment, may have dire ramifications. This study aimed to ...assess whether certain comorbidities and previous surgical procedures coincide with resistance determinants of AmpC-producing Enterobacterales associated with bloodstream infections. Antibiotic resistance patterns and therapy outcome were also determined. The patients’ data obtained revealed that the prevalence of recent surgical procedures, solid organ tumors, metabolic diseases, kidney and liver failure, and hematological malignancies do not differ between resistant and susceptible isolates of AmpC-producing Enterobacterales. Furthermore, no difference was reported in mortality rates. Regarding antibiotic resistance, 34.52% of isolates were confirmed to be resistant (AmpC hyperproduction, ESBL, or carbapenemase). More than one in five AmpC hyperproducers were reported amid Providencia spp., K. aerogenes, E. cloacae, and C. freundii. strains. Carbapenemases were mostly noted in Providencia spp. followed by M. morganii and K. aerogenes strains. Serratia marcescens had the highest proportion of ESBLsof ESBLs. Resistance to expanded-spectrum cephalosporins of Providencia spp. and K. aerogenes strains exceeded 50%, and resistance to meropenem over 10% was observed only in C. freundii strains. Enterobacterales’ ever-growing resistance to antibiotics is becoming quite a challenge for clinicians and new treatment options are required.
K. pneumoniae
isolates often harbor various antibiotic resistance determinants including extended-spectrum β-lactamases (ESBLs), plasmid-mediated AmpC β-lactamases (p-Amp-C) and carbapenemases. In ...this study we analyzed 65 K
. pneumoniae
isolates obtained from urinary tract infections in the outpatients setting, with regard to antibiotic susceptibility, β-lactamase production, virulence traits and plasmid content.
Antibiotic susceptibility was determined by broth microdilution method. PCR was applied to detect genes encoding ESBLs, p-Amp-C and carbapenemases and plasmid incompatibility groups. Phenotypic methods were applied to characterize virulence determinants. Increasing resistance trend was observed for amoxicillin/clavulanate, imipenem, meropenem and ciprofloxacin. The study showed that ESBLs belonging to the CTX-M family, conferring high level of resistance to expanded-spectrum cephalosporins (ESC) were the dominant resistance trait among early isolates (2013 to 2016) whereas OXA-48 carbapenemase, belonging to class D, emerged in significant numbers after 2017. OXA-48 producing organisms coharbored ESBLs. KPC-2 was dominant among isolates from Dubrovnik in the recent years. Colistin resistance was reported in three isolates. Inc L/M was the dominant plasmid in the later period, encoding OXA-48. Hyperviscosity was linked to KPC positivity and emerged in the later period. This report describes evolution of antibiotic resistance in
K. pneumoniae
from ESBLs to carbapenemases and colistin resistance. The study demonstrated the ability of
K. pneumoniae
to acquire various resistance determinants, over time. The striking diversity of the UTI isolates could result from introduction of the isolates from the hospitals, transfer of plasmids and multidirectional evolution.
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