Activity of temocillin against ESBL-, AmpC-, and/or KPC-producing Enterobacterales isolated in Poland

Real-life use of temocillin in the treatment of bone and joint infections due to extended spectrum β-lactamase-producing Enterobacterales

Objectives

The aim of this study is to describe the real-life use of temocillin in bone and joint infections (BJI).

Patients and methods

We performed a monocentric retrospective study, including all patients treated by temocillin for a BJI due to extended spectrum β-lactamase-producing Enterobacterales (ESBL-E) between 1 January 2015 and 31 December 2022. Outcomes were evaluated at least 3 months after the end of antimicrobial treatment. Clinical cure was defined as the absence of recurrence of BJI during follow-up among patients who completed at least 7 days of temocillin. If the patient discontinued temocillin due to ineffectiveness, the outcome was considered to be unfavourable. Seventeen patients were treated with temocillin for ESBL-E associated BJI during the study period.

Results

Infections included osteomyelitis of the foot (7/17; 41.2%), femoral osteomyelitis (4/17; 23.5%), disco-vertebral infections (2/17; 11.8%), total knee prosthesis infections (2/17; 11.8%) and total hip prosthesis infections (2/17; 11.8%). All patients except one (n = 16) had surgical management of the infection. The main bacteria identified were the Enterobacter cloacae complex (n = 9) and Klebsiella pneumoniae (n = 5). The median daily dose was 6 g for a median duration of 42 days (IQR 14-42 days). The median duration of follow-up was 12 months (IQR 5.25-14.5). Overall, 12 patients completed at least 3 months of follow-up, and clinical cure was observed in eight of them (8/12; 66.7%).

Conclusion

So far, this is the first report of BJI successfully treated with temocillin. This suggests that temocillin may be an alternative to treat BJI involving difficult-to-treat Enterobacterales when oral therapy is not available.

Insights into the Rising Threat of Carbapenem-Resistant Enterobacterales and Pseudomonas aeruginosa Epidemic Infections in Eastern Europe: A Systematic Literature Review

BACKGROUND

Antimicrobial resistance is a major global public health challenge, particularly with the rise of carbapenem-resistant Enterobacterales (CRE) and Pseudomonas aeruginosa (CRPA). This study aimed to describe the characteristics of CRE and CRPA infections in Eastern Europe, focusing on Bulgaria, Croatia, Czechia, Greece, Hungary, Poland, Romania, Serbia, Slovakia, and Slovenia.

METHODS

Following MOOSE and PRISMA guidelines, a systematic literature review of articles published between 1 November 2017 and 1 November 2023 was conducted using the MEDLINE, Embase, Web of Science, CDSR, DARE, and CENTRAL databases. The search strategy used a combination of free text and subject headings to gather pertinent literature regarding the incidence and treatment patterns of CRE and CRPA infections. A total of 104 studies focusing on infections in both children and adults were included in this review.

RESULTS

This review revealed a significant prevalence of carbapenem-resistant Gram-negative isolates and underscored the effectiveness of imipenem/relebactam and ceftazidime/avibactam (CAZ/AVI) against Klebsiella pneumoniae carbapenemase-producing Enterobacterales and of ceftolozane/tazobactam, imipenem/relebactam and ceftazidime/avibactam against non-metallo-β-lactamase-producing CRPA strains.

CONCLUSIONS

This study highlights the urgent need for comprehensive measures to combat the escalating threat of CRE and CRPA infections in Eastern European countries. At the same time, it shows the activity of the standard of care and new antimicrobials against carbapenem-resistant Gram-negative pathogens in Eastern Europe. Clinical real-world data on the treatment of carbapenem-resistant infections in Eastern Europe are needed.

Inter-phylum circulation of a beta-lactamase-encoding gene: a rare but observable event

Beta-lactamase-mediated degradation of beta-lactams is the most common mechanism of beta-lactam resistance in Gram-negative bacteria. Beta-lactamase-encoding genes can be transferred between closely related bacteria, but spontaneous inter-phylum transfers (between distantly related bacteria) have never been reported. Here, we describe an extended-spectrum beta-lactamase (ESBL)-encoding gene (blaMUN-1) shared between the Pseudomonadota and Bacteroidota phyla. An Escherichia coli strain was isolated from a patient in Münster (Germany). Its genome was sequenced. The ESBL-encoding gene (named blaMUN-1) was cloned, and the corresponding enzyme was characterized. The distribution of the gene among bacteria was investigated using the RefSeq Genomes database. The frequency and relative abundance of its closest homolog in the global microbial gene catalog (GMGC) were analyzed. The E. coli strain exhibited two distinct morphotypes. Each morphotype possessed two chromosomal copies of the blaMUN-1 gene, with one morphotype having two additional copies located on a phage-plasmid p0111. Each copy was located within a 7.6-kb genomic island associated with mobility. blaMUN-1 encoded for an extended-spectrum Ambler subclass A2 beta-lactamase with 43.0% amino acid identity to TLA-1. blaMUN-1 was found in species among the Bacteroidales order and in Sutterella wadsworthensis (Pseudomonadota). Its closest homolog in GMGC was detected frequently in human fecal samples. This is, to our knowledge, the first reported instance of inter-phylum transfer of an ESBL-encoding gene, between the Bacteroidota and Pseudomonadota phyla. Although the gene was frequently detected in the human gut, inter-phylum transfer was rare, indicating that inter-phylum barriers are effective in impeding the spread of ESBL-encoding genes, but not entirely impenetrable.

Carbapenem-Resistant Klebsiella pneumoniae: Virulence Factors, Molecular Epidemiology and Latest Updates in Treatment Options

Klebsiella pneumoniae is a Gram-negative opportunistic pathogen responsible for a variety of community and hospital infections. Infections caused by carbapenem-resistant K. pneumoniae (CRKP) constitute a major threat for public health and are strongly associated with high rates of mortality, especially in immunocompromised and critically ill patients. Adhesive fimbriae, capsule, lipopolysaccharide (LPS), and siderophores or iron carriers constitute the main virulence factors which contribute to the pathogenicity of K. pneumoniae. Colistin and tigecycline constitute some of the last resorts for the treatment of CRKP infections. Carbapenemase production, especially K. pneumoniae carbapenemase (KPC) and metallo-β-lactamase (MBL), constitutes the basic molecular mechanism of CRKP emergence. Knowledge of the mechanism of CRKP appearance is crucial, as it can determine the selection of the most suitable antimicrobial agent among those most recently launched. Plazomicin, eravacycline, cefiderocol, temocillin, ceftolozane-tazobactam, imipenem-cilastatin/relebactam, meropenem-vaborbactam, ceftazidime-avibactam and aztreonam-avibactam constitute potent alternatives for treating CRKP infections. The aim of the current review is to highlight the virulence factors and molecular pathogenesis of CRKP and provide recent updates on the molecular epidemiology and antimicrobial treatment options.

Current and Emerging Treatment Options for Multidrug Resistant Escherichia coli Urosepsis: A Review

Escherichia coli is a versatile commensal and pathogenic member of the human microflora. As the primary causative pathogen in urosepsis, E. coli places an immense burden on healthcare systems worldwide. To further exacerbate the issue, multi drug resistance (MDR) has spread rapidly through E. coli populations, making infections more troublesome and costlier to treat. This paper aimed to review the literature concerning the development of MDR in uropathogenic E. coli (UPEC) and explore the existing evidence of current and emerging treatment strategies. While some MDR strains maybe treated with β-lactam-β-lactamase inhibitor combinations as well as cephalosporins, cephamycin, temocillin and fosfomycin, current treatment strategies for many MDR UPEC strains are reliant on carbapenems. Carbapenem overreliance may contribute to the alarming dissemination of carbapenem-resistance amongst some UPEC communities, which has ushered in a new age of difficult to treat infections. Alternative treatment options for carbapenem resistant UPEC may include novel β-lactam-β-lactamase or carbapenemase inhibitor combinations, cefiderocol, polymyxins, tigecycline, aminoglycosides or fosfomycin. For metallo-β-lactamase producing strains (e.g., NDM, IMP-4), combinations of cefazidime-avibacam with aztreonam have been used. Additionally, the emergence of new antimicrobials brings new hope to the treatment of such infections. However, continued research is required to successfully bring these into the clinic for the treatment of MDR E. coli urosepsis.

Population Pharmacokinetics of Temocillin Administered by Continuous Infusion in Patients with Septic Shock Associated with Intra-Abdominal Infection and Ascitic Fluid Effusion

Temocillin is active against Gram-negative bacteria, including many extended-spectrum β-lactamase (ESBL)-producing Enterobacterales. We studied its pharmacokinetics in plasma and ascitic fluid after intravenous administration of a loading dose of 2 g over 30 min, followed by continuous infusion of 6 g/24 h, to 19 critically-ill patients with septic shock associated with complicated intra-abdominal infection. We established a pharmacokinetic model describing unbound temocillin concentrations in plasma and ascitic fluid and performed Monte-Carlo simulations to evaluate the probability of target attainment (PTA) of unbound concentrations (100% fT > MIC, i.e., unbound concentrations remaining above the MIC during 100% of the time) for the applied and hypothetical dosing regimens. The temocillin AUC in ascitic fluid was 46% of the plasma AUC. Plasma unbound concentrations were best described by a two-compartment model, and an additional compartment was added to describe unbound concentration in ascitic fluid, with renal clearance as a covariate. Dosing simulations showed that 90% PTA was achieved in the plasma with the current dosing regimen for MIC ≤ 16 mg/L (EUCAST susceptibility breakpoint) but not in the ascitic fluid if renal clearance was ≥40 mL/min. Hypothetical dosing with a higher (a) loading dose or (b) infused dose allowed to reach target concentrations in ascitic fluid (a) more rapidly or (b) sustainably, but these simulations need to be evaluated in the clinics for safety and efficacy.

CTX-M-producing Escherichia coli strains: resistance to temocillin, fosfomycin, nitrofurantoin and biofilm formation

Aim: ESBL-producing and bacterial biofilms-forming Escherichia coli are associated with antimicrobial treatment failure. This study aimed to investigate the phenotypic resistance mechanisms of CTX-M E. coli against old antibiotics - cell wall synthesis inhibitors temocillin, nitrofurantoin and fosfomycin. Materials & Methods: Susceptibility to old antibiotics testing was performed using disk diffusion method, biofilm formation was evaluated spectrophotometrically, and PCR was used for the determination of CTX-M type. Results & conclusion: Temocillin was active against nearly 93%, nitrofurantoin and fosfomycin, respectively, 91.7% and 98.6% of tested E. coli. Thus, it demonstrated to be a good alternative therapeutic option against ESBL infections. Bacteria resistant to old antibiotics had CTX-M-15 or CTX-M-15, TEM-1 and OXA-1 combinations. No significant association was found between CTX-M E. coli resistance to temocillin, nitrofurantoin and fosfomycin; however, the level of biofilm formation was found as not affected by the type of CTX-M β-lactamases.

Temocillin: Applications in Antimicrobial Stewardship as a Potential Carbapenem-Sparing Antibiotic

Temocillin is an old antibiotic, but given its particular characteristics, it may be a suitable alternative to carbapenems for treating infections due to ESBL-producing Enterobacterales and uncomplicated UTI due to KPC-producers. In this narrative review, the main research question was to summarize current evidence on temocillin and its uses in infectious diseases. A search was run on PubMed using the terms (‘Temocillin’ [Mesh]) AND (‘Infection’ [Mesh]). Current knowledge regarding temocillin in urinary tract infection, blood-stream infections, pneumonia, intra-abdominal infections, central nervous system infections, skin and soft tissues infections, surgical sites infections and osteoarticular Infections were summarized. Temocillin retain a favourable profile on microbiota and risk of Clostridioides difficile infections and could be an option for treating outpatients. Temocillin may be a valuable tool to treat susceptible pathogens and for which a carbapenem could be spared. Other advantages in temocillin use are that it is well-tolerated; it is associated with a low rate of C. difficile infections; it is active against ESBL, AmpC, and KPC-producing Enterobacterales; and it can be used in the OPAT clinical setting.

Activity of temocillin against third-generation cephalosporin-resistant Escherichia coli and Klebsiella pneumoniae bloodstream isolates from a clinical trial

Background

Extended spectrum β-lactamase (ESBL) and AmpC-producing Gram-negative bacilli contribute significantly to the antimicrobial resistance (AMR) burden worldwide. Temocillin is an intravenous semisynthetic antibiotic that is stable to hydrolysis by ESBLs and AmpC. Temocillin may be a treatment option for serious infections due to these organisms.

Methods

Third-generation cephalosporin-resistant Escherichia coli and Klebsiella pneumoniae isolates from the MERINO trial were collected. The majority originated from the urinary tract. Isolates had previously undergone whole genome sequencing (WGS) to identify antimicrobial resistance genes. Temocillin minimum inhibitory concentration (MIC) values were determined by broth microdilution (BMD) with a concentration range of 2 to 128 mg/L. A recent EUCAST guideline has recommended clinical breakpoints for urinary E. coli, Klebsiella spp. (except K. aerogenes) and Proteus mirabilis (resistant >16 mg/L).

Results

317 index bloodstream isolates (275 E. coli and 42 K. pneumoniae) were used. The frequency of β-lactamases among isolates was: CTX-M-15 (56%), OXA-1 (31%), CTX-M-27 (14%), CTX-M-14 (12%) and CMY-2 (8%). Overall, 95% of isolates were susceptible, increased exposure according to EUCAST clinical breakpoints v11.0. Summary MIC values were obtained: MIC50 was 8 mg/L and MIC90 was16 mg/L (range ≤2 to ≥128 mg/L) and did not differ markedly between species. Higher MIC values were seen among isolates that produced more than one β-lactamase but this did not appear to be specific to a single β-lactamase.

Conclusions

Temocillin demonstrated favourable in vitro activity against ceftriaxone-resistant Enterobacterales bloodstream isolates and may be a suitable agent to be trialled for treatment of serious infections due to these organisms.

Comparative in vitro activity of piperacillin-tazobactam and temocillin against third-generation cephalosporin-resistant, carbapenem-susceptible Escherichia coli and Klebsiella pneumoniae

Carbapenems are considered the drugs of choice for first-line treatment of severe infections caused by carbapenem-susceptible, extended-spectrum β-lactamases (ESBL)-producing Enterobacterales, while piperacillin-tazobactam has been recommended as an alternative for treatment of non-severe infections. Temocillin is stable to ESBL and AmpC enzymes and may thus represent another treatment option. This study assessed the in vitro activity of piperacillin-tazobactam and temocillin against third-generation cephalosporin (3GC)-resistant Esch erichia coli and Klebsiella pneumoniae, as compared to 3GC-susceptible isolates of either species. One hundred and nine isolates from hospitalized patients with bloodstream and urinary tract infections were tested. All isolates were collected during the resistance surveillance study of the Paul-Ehrlich-Society for Chemotherapy in 2016/17. Minimum inhibitory concentrations (MICs) were determined by broth microdilution according to the standard ISO 20776-1 and interpreted using EUCAST clinical breakpoints (version 11.0). Seventy-nine isolates (E. coli, n=58; K. pneumoniae, n=21) were 3GC-resistant and 30 (E. coli, n=15; K. pneumoniae, n=15) were 3GC-susceptible. Susceptibility to piperacillin-tazobactam was detected in 93.3% of 3GC-susceptible isolates (for both E. coli and K. pneumoniae) and in 79.3% and 57.1% of the 3GC-resistant E. coli and K. pneumoniae, respectively. In contrast, 3GC-susceptible isolates were 100% susceptible to temocillin as were 94.8% and 90.5% of the 3GC-resistant E. coli and K. pneumoniae, respectively. In conclusion, temocillin demonstrated potent in vitro activity against carbapenem-susceptible, 3GC-resistant E. coli and K. pneumoniae from bloodstream and urinary tract infection samples, with susceptibility rates exceeding those of piperacillin-tazobactam.

The clinical and microbiological efficacy of temocillin versus cefotaxime in adults with febrile urinary tract infection, and its effects on the intestinal microbiota: a randomised multicentre clinical trial in Sweden

BACKGROUND

Use of third-generation cephalosporins, such as cefotaxime, is associated with an increased risk of selection for antimicrobial resistance, so alternative antibiotics need to be considered. The aim of the present study was to evaluate intestinal colonisation with third-generation cephalosporin-resistant pathogens following use of temocillin-an alternative antibiotic to cefotaxime that is potentially less prone to disturbing the intestinal microbiota-in empirical treatment of febrile urinary tract infection (UTI).

METHODS

We did a randomised, multicentre, superiority, open-label phase 4 trial in patients who had been admitted to inpatient care in 12 Swedish hospitals with suspected or diagnosed febrile UTI (complicated or uncomplicated). To meet inclusion criteria, a patient was required to have at least one sign or symptom of pyelonephritis (ie, flank pain; costovertebral angle tenderness; and changes to urinary frequency or urgency or dysuria), a fever of 38·0°C or higher, and a positive urine dipstick (for nitrites, white blood cells, or both). Participants were also required to have an indication for intravenous antibiotic treatment. Participants were randomly assigned (1:1) to receive either 2 g temocillin or 1-2 g cefotaxime, by local investigators opening consecutive sealed randomisation envelopes that were generated centrally in advance. Both drugs were administered intravenously every 8 h. The trial was open label for investigators and patients, but those doing the microbiological analyses were masked to the groups. Participants were treated with antibiotics for 7-10 days (or up to 14 days if they had bacteraemia), at least 3 days of which were on the study drug; at day 4 and later, participants who were showing improvement could be given an oral antibiotic (ciprofloxacin, ceftibuten, cefixime, or co-trimoxazole). Patients not showing improvement were regarded as having treatment failures. Rectal swabs were collected at three timepoints: at baseline (before the first dose), after the last dose of study drug, and 7-10 days after treatment stopped. The composite primary outcome was colonisation with Enterobacterales with reduced susceptibility to third-generation cephalosporins, or colonisation with toxin-producing Clostridioides difficile, or both, to evaluate disturbance of the intestinal microbiota. The study is registered in the EU Clinical Trials Register (EudraCT 2015-003898-15).

FINDINGS

Between May 20, 2016, and July 31, 2019, 207 patients were screened for eligibility, of whom 55 patients were excluded. 152 participants were randomly assigned to groups: 77 (51%) patients received temocillin, 75 (49%) patients received cefotaxime. The composite primary endpoint was met by 18 (26%) of 68 participants receiving temocillin versus 30 (48%) of 62 patients receiving cefotaxime (risk difference -22% [95% CI -42% to -3%]), showing superiority of temocillin versus cefotaxime (ie, less disturbance of the intestinal microbiota). 43 adverse events were reported in 40 (52%) of 77 patients in the temocillin group, versus 46 adverse events in 34 (45%) of 75 patients in the cefotaxime group. Most events were of mild to moderate severity. 21 (27%) patients in the temocillin and 17 (23%) patients in the cefotaxime group had an adverse event that was considered to be associated with the study drug.

INTERPRETATION

Temocillin was found to be less selective than cefotaxime of Enterobacterales with reduced susceptibility to third-generation cephalosporins, and it could therefore be a favourable alternative in the empirical treatment of febrile UTI. Use of this antibiotic could reduce hospital transmission and health-care-associated infections by these pathogens.

FUNDING

Public Health Agency of Sweden.

Temocillin versus carbapenems for urinary tract infection due to ESBL-producing Enterobacteriaceae: a multicenter matched case-control study

OBJECTIVES

To compare the efficacy of temocillin with carbapenems for extended spectrum β-lactamase (ESBL)-producing Enterobacteriaceae urinary tract infections (ESBL-E UTI).

METHODS

A multicenter retrospective case-control study of adults with ESBL-E UTI was conducted between January 2015 and October 2019. Cases received temocillin ≥ 50% of the effective antibiotic therapy duration and controls exclusively received carbapenem; they were statistically matched (1:1 ratio) on 6-month period, sex and age. The clinical cure at the end of antibiotic therapy was analysed using conditional logistic regression.

RESULTS

Seventy-two temocillin cases were matched to 72 carbapenem controls. Most (67%) were male, median age was 69.4 years, 81 (56%) were immunocompromised, including 44 (31%) solid organ transplant recipients. There was no difference between cases and controls for baseline characteristics and microorganisms involved: Klebsiella pneumoniae in 59 (41%), Escherichia coli in 57 (40%), and Enterobacter spp. in 24 (17%). The median time from admission to effective antibiotic therapy was 0 days [range, 0-2]. Among cases, first-line antibiotic therapy (≤ 72 hours) was temocillin in six (8%) and carbapenems in 39 (54%). Temocillin was given at the median daily dose of 4 g [range, 2-4] after 3 days [range, 2-5] of carbapenems. Patients received temocillin for 81% [range, 70-93] of the effective antibiotic course duration over 11 days [range, 8-14]. The effective antibiotic duration was similar in cases and controls (P = 0.067). Clinical cure at the end of antibiotic therapy was 94% (68/72) in cases vs. 99% (71/72) in controls (P = 0.206), with no difference among immunocompromised and solid organ transplant patients (P > 0.050).

CONCLUSIONS

Temocillin effectively relayed β-lactams, including carbapenems, to treat (complicated) ESBL-E UTI. Its efficacy was consistent among kidney transplant recipients.

Prevalence, serotyping and drug susceptibility patterns of Escherichia coli isolates from kidney transplanted patients with urinary tract infections

BACKGROUND

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) are among the main pathogens in urinary tract infections (UTIs) among kidney transplant patients (KTPs).

AIM

To estimate the prevalence of ESBL-producing E. coli in KTPs and to evaluate the most prevalent serotypes and antibacterial susceptibility patterns of isolated bacteria in Tehran, Iran.

METHODS

A total of 60 clinical isolates of uropathogenic E. coli were collected from 3 kidney transplant centers from April to May 2019. Antimicrobial susceptibility testing was performed by the disk diffusion method as recommended by the Clinical Laboratory and Standards Institute. The serotyping of E. coli isolates was performed by the slide agglutination method. The presence of bla_TEM, bla_SHV, and bla_CTX-M genes was evaluated by polymerase chain reaction.

RESULTS

The frequency of ESBL-producing E. coli in KTPs was found to be 33.4%. All of the 60 E. coli isolates were found to be susceptible to doripenem (100%) and ertapenem (100%). High resistance rates to ampicillin (86%), cefotaxime (80%), and cefazolin (77%) were also documented. The most frequent serotypes were serotype I (50%), serotype II (15%), serotype III (25%), and serotype VI (10%). The gene most frequently found was bla_TEM (55%), followed by bla_CTX-M (51%) and bla_SHV (41%).

CONCLUSION

Molecular analysis showed that bla_TEM was the most common ESBL-encoding gene. The high resistance to β-lactams antibiotics (i.e., ampicillin, cefotaxime, and cefazolin) found in E. coli from KTPs with UTIs remains a serious clinical challenge. Further efforts to control ESBL-producing E. coli should include the careful use of all antibiotics as well as barrier precautions to reduce spread.