Tigecycline: A Review of Properties, Applications, and Analytical Methods

Carbapenem-resistant Enterobacterales sepsis following endoscopic retrograde cholangiopancreatography: risk factors for 30-day all-cause mortality and the development of a nomogram based on a retrospective cohort

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) has become a routine endoscopic procedure that is essential for diagnosing and managing various conditions, including gallstone extraction and the treatment of bile duct and pancreatic tumors. Despite its efficacy, post-ERCP infections - particularly those caused by carbapenem-resistant Enterobacterales (CRE) - present significant risks. These risks highlight the need for accurate predictive models to enhance postprocedural care, reduce the mortality risk associated with post-ERCP CRE sepsis, and improve patient outcomes in the context of increasing antibiotic resistance.

OBJECTIVE

This study aimed to examine the risk factors for 30-day mortality in patients with CRE sepsis following ERCP and to develop a nomogram for accurately predicting 30-day mortality risk.

METHODS

Data from 195 patients who experienced post-ERCP CRE sepsis between January 2010 and December 2022 were analyzed. Variable selection was optimized via the least absolute shrinkage and selection operator (LASSO) regression model. Multivariate logistic regression analysis was then employed to develop a predictive model, which was evaluated in terms of discrimination, calibration, and clinical utility. Internal validation was achieved through bootstrapping.

RESULTS

The nomogram included the following predictors: age > 80 years (hazard ratio [HR] 2.61), intensive care unit (ICU) admission within 90 days prior to ERCP (HR 2.64), hypoproteinemia (HR 4.55), quick Pitt bacteremia score ≥ 2 (HR 2.61), post-ERCP pancreatitis (HR 2.52), inappropriate empirical therapy (HR 3.48), delayed definitive therapy (HR 2.64), and short treatment duration (< 10 days) (HR 5.03). The model demonstrated strong discrimination and calibration.

CONCLUSIONS

This study identified significant risk factors associated with 30-day mortality in patients with post-ERCP CRE sepsis and developed a nomogram to accurately predict this risk. This tool enables healthcare practitioners to provide personalized risk assessments and promptly administer appropriate therapies against CRE, thereby reducing mortality rates.

Inhalable Excipient-Free Dry Powder of Tigecycline for the Treatment of Pulmonary Infections

Tigecycline (TIG) is a broad-spectrum antibiotic that has been approved for the treatment of a number of complicated infections, including community-acquired bacterial pneumonia. Currently it is available only as an intravenous injection that undergoes rapid chemical degradation and limits the use to in-patient scenarios. The use of TIG as an inhaled dry powder inhaler may offer a promising treatment option for patients with multidrug-resistant respiratory tract infections, such as Stenotrophomonas maltophilia (S. maltophilia). This study explores the feasibility of engineering an inhaled powder formulation of TIG that could administer relevant doses at a wide range of inhalation flow rates while maintaining stability of this labile drug. Using air-jet milling, micronized TIG had excellent aerosolization efficiency, with over 80% of the device emitted dose being within the respirable range. TIG was also readily dispersed using different inhaler devices even when tested at different pressure drops and flow rates. Additionally, micronized TIG was stable for 6 months at 25 °C/60% RH and 40 °C/75% RH. Micronized TIG maintained a low minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) of 0.8 μM and >0.5 μM, respectively in S. maltophilia cultures in vitro. These results strongly suggest that the micronization of TIG results in a stable and respirable formulation that can be delivered via the pulmonary route for the treatment of lung infections.

Central composite design driven optimization of sustainable stability indicating HPLC method for the determination of Tigecycline and greenness assessment

Background: Tigecycline (TGC) is a recently developed antibiotic to battle resistant bacteria. The procedures outlined in the literature for analyzing TGC involve chemical solvents that could be hazardous. Therefore, this study aimed to create a sustainable and stable HPLC technique for quantifying Tigecycline in lyophilized powder. The powerful chemometric tool, experimental design (ED), will be applied to analyze the variables' interaction and impact on the selected analytical target profiles. Response surface methodology provides a tutorial on using the central composite design with three levels of variables and quadratic programming to optimize the design space of the developed method. Methods: The New HPLC method consisted of an aqueous buffer and ethanol as a green mobile phase run on a reversed-phase symmetry C18 column. A full resolution between the Tigecycline and its degradation product peaks was achieved in a short analytical runtime. Results: Further, the specificity, accuracy, precision, robustness and stability indicating power of the proposed approach were verified through stress degrading testing. Conclusions: Finally, the analytical eco-scale and the green Analytical Procedure Index (GAPI) were utilized to determine how environmentally friendly the recommended method was compared to other published approaches.

Central composite design driven optimization of sustainable stability indicating HPLC method for the determination of Tigecycline and greenness assessment

Background: Tigecycline (TGC) is a recently developed antibiotic to battle resistant bacteria. The procedures outlined in the literature for analyzing TGC involve chemical solvents that could be hazardous. Therefore, this study aimed to create a sustainable and stable HPLC technique for quantifying Tigecycline in lyophilized powder. The powerful chemometric tool, experimental design (ED), will be applied to analyze the variables' interaction and impact on the selected analytical target profiles. Response surface methodology provides a tutorial on using the central composite design with three levels of variables and quadratic programming to optimize the design space of the developed method. Methods: The New HPLC method consisted of an aqueous buffer and ethanol as a green mobile phase run on a reversed-phase symmetry C18 column. A full resolution between the Tigecycline and its degradation product peaks was achieved in a short analytical runtime. Results: Further, the specificity, accuracy, precision, robustness and stability indicating power of the proposed approach were verified through stress degrading testing. Conclusions: Finally, the analytical eco-scale and the green Analytical Procedure Index (GAPI) were utilized to determine how environmentally friendly the recommended method was compared to other published approaches.

Progress of tissue adhesives based on proteins and synthetic polymers

In recent years, polymer-based tissue adhesives (TAs) have been developed as an alternative to sutures to close and seal incisions or wounds owing to their ease of use, rapid application time, low cost, and minimal tissue damage. Although significant research is being conducted to develop new TAs with improved performances using different strategies, the applications of TAs are limited by several factors, such as weak adhesion strength and poor mechanical properties. Therefore, the next-generation advanced TAs with biomimetic and multifunctional properties should be developed. Herein, we review the requirements, adhesive performances, characteristics, adhesive mechanisms, applications, commercial products, and advantages and disadvantages of proteins- and synthetic polymer-based TAs. Furthermore, future perspectives in the field of TA-based research have been discussed.

Analysis of Efflux Pump System and Other Drug Resistance Related Gene Mutations in Tigecycline-Resistant Acinetobacter baumannii

Background

The isolation of tigecycline-resistant Acinetobacter baumannii in recent years has brought great difficulties to clinical prevention and treatment.

Purpose

To explore the effect of efflux pump system and other resistance related gene mutations on tigecycline resistance in Acinetobacter baumannii.

Methods

Fluorescence quantitative PCR was used to detect the expression levels of major efflux pump genes (adeB, adeJ, and adeG) in extensive drug-resistant Acinetobacter baumannii. The minimum inhibitory concentration (MIC) of tigecycline was detected by the broth microdilution testing and efflux pump inhibition experiment to assess the role of efflux pump in tigecycline resistance of Acinetobacter baumannii. Efflux pump regulatory genes (adeR and adeS) and tigecycline resistance related genes (rpsJ, trm, and plsC) were amplified by PCR and sequenced. By sequence alignment, tigecycline sensitive and tigecycline-insensitive Acinetobacter baumannii were compared with standard strains to analyze the presence of mutations in these genes.

Results

The relative expression of adeB in the tigecycline-insensitive Acinetobacter baumannii was significantly higher than that in the tigecycline sensitive Acinetobacter baumannii (114.70 (89.53-157.43) vs 86.12 (27.23-129.34), P = 0.025). When efflux pump inhibitor carbonyl cyanide 3-chlorophenylhydrazone (CCCP) was added, the percentage of tigecycline-insensitive Acinetobacter baumannii with tigecycline MIC decreased was significantly higher than that of tigecycline-sensitive Acinetobacter baumannii (10/13 (76.9%) vs 26/59 (44.1%)), P = 0.032); the relative expression of adeB in the MIC decreased group was significantly higher than that in the MIC unchanged group (110.29 (63.62-147.15) vs 50.06 (26.10-122.59), P = 0.02); The relative expression levels of efflux pumps adeG and adeJ did not increase significantly, and there was no significant difference between these groups. One adeR point mutation (Gly232Ala) and eight adeS point mutations (Ala97Thr, Leu105Phe, Leu172Pro, Arg195Gln, Gln203Leu, Tyr303Phe, Lys315Asn, Gly319Ser) were newly detected. Consistent mutations in trm and plsC genes were detected in both tigecycline-insensitive and tigecycline-sensitive Acinetobacter baumannii, but no mutation in rpsJ gene was detected in them.

Conclusion

Tigecycline-insensitive Acinetobacter baumannii efflux pump adeABC overexpression was an important mechanism for tigecycline resistance, and the mutations of efflux pump regulator genes (adeR and adeS) are responsible for adeABC overexpression. The effect of trm, plsC, and rpsJ gene mutations on the development of tigecycline resistance in Acinetobacter baumannii remains controversial.

Sub-Inhibitory Concentrations of Oxacillin, but Not Clindamycin, Linezolid, or Tigecycline, Decrease Staphylococcal Phenol-Soluble Modulin Expression in Community-Acquired Methicillin-Resistant Staphylococcus aureus

Staphylococcus aureus (SA) is a major human pathogen producing virulence factors, such as Panton-Valentine-leucocidin (PVL), alpha-hemolysin (Hla), and phenol-soluble-modulins alpha (PSMα), including delta-hemolysin (Hld). Unlike oxacillin, clindamycin and linezolid subinhibitory concentrations (sub-MIC) display an anti-toxin effect on PVL and Hla expression. Few studies have investigated PSMα and Hld expression modulation by antibiotics. Herein, we assessed the effect of antibiotic sub-MIC on PSMα1 and Hld expression for 4 community-acquired methicillin-resistant SA (CA-MRSA), 2 strains belonging to USASA300 and 2 strains belonging to ST80 European clone. SA were grown under oxacillin, clindamycin, linezolid, or tigecycline. After incubation, culture pellets were used for the determination of psmα1, pmtB, pmtR mRNA, and RNAIII levels by relative quantitative RT-PCR. PSMα1 and Hld expressions were measured in supernatant using high-performance-liquid-chromatography coupled to mass-spectrometry (HPLC-MS). Oxacillin sub-MIC reduced PSMα1 and Hld production, partially related to mRNA variations. For other antibiotics, effects on toxin expression were strain or clone dependent. Antibiotic effect on mRNA did not always reflect protein expression modulation. Variations of pmtB, pmtR mRNA, and RNAIII levels were insufficient to explain toxin expression modulation. Altogether, these data indicate that PSMα and Hld expressions are modulated by antibiotics (potential anti-toxin effect of oxacillin) differently compared to PVL and Hla.

IMPORTANCE Staphylococcal toxins play an important role in the physiopathology of staphylococcal infections. Subinhibitory concentrations (sub-MIC) of antibiotics modulate in vitro toxins expression in S. aureus: clindamycin (CLI) and linezolid (LIN) display an anti-toxin effect on Panton-Valentine leucocidin and alpha-hemolysin production, while oxacillin (OXA) has an inducing effect. Few studies have focused on the modulation of phenol-soluble modulins alpha (PSMα) including delta-hemolysin expression by sub-MIC antibiotics. The aim of the present study was to investigate the effects of sub-MIC antibiotics on the expression of PSMα toxins for 4 community-acquired methicillin-resistant S. aureus (CA-MRSA) clinical isolates. The data presented herein confirm that OXA sub-MICs constantly inhibit PSMα production for CA-MRSA. Certain strains of S. aureus are highly sensitive to sub-MICs of protein synthesis inhibitory agents, resulting in an important increase of mRNA levels to overcome the intrinsic ribosome blockage ability of these antibiotics, eventually translating in increased expression of toxins.

Preparation, characterization, and antibacterial activity of tigecycline-loaded, ultrasound-activated microbubbles

Central nervous system infectious disease caused by the multidrug-resistant Acinetobacter baumannii (AB) seriously threatens human life in clinic. Tigecycline has good sensitivity in killing AB, but due to its wide tissue distribution and blood-brain barrier, concentration in cerebrospinal fluid is low, therefore, the clinical effect is limited. Herein, we designed micro-bubbled tigecycline, aimed to enhance its anti-MDRAB effects under ultrasound. The lipid microbubbles with different ratios of lipids to drugs (a ratio of 10:1, 20:1, and 40:1) were prepared by the mechanical shaking method. The morphology, zeta potential and particle size of microbubbles were tested to screen out the much better formulation. Encapsulation efficiency and drug loading amount were determined by ultracentrifugation combined with high-performance liquid chromatography. Then the in vitro antibacterial activity against AB was conducted using the selected ultrasound-activated microbubble. Results showed the selected microbubbles with high encapsulation efficiency and good stability. The mechanical shaking method is feasible for preparation of drug-loaded and ultrasound-activated lipid microbubbles. Using 0.2 mg/mL microbubbles, combined with 1 MHz, 2.5 W/cm² and 1 min of ultrasound exhibited a potent anit-AB in vitro. This study indicates that tigecycline treatment in form of ultrasound-activated microbubble is a promising strategy against AB infections.

The Development of Third-Generation Tetracycline Antibiotics and New Perspectives

The tetracycline antibiotic class has acquired new valuable members due to the optimisation of the chemical structure. The first modern tetracycline introduced into therapy was tigecycline, followed by omadacycline, eravacycline, and sarecycline (the third generation). Structural and physicochemical key elements which led to the discovery of modern tetracyclines are approached. Thus, several chemical subgroups are distinguished, such as glycylcyclines, aminomethylcyclines, and fluorocyclines, which have excellent development potential. The antibacterial spectrum comprises several resistant bacteria, including those resistant to old tetracyclines. Sarecycline, a narrow-spectrum tetracycline, is notable for being very effective against Cutinebacterium acnes. The mechanism of antibacterial action from the perspective of the new compound is approached. Several severe bacterial infections are treated with tigecycline, omadacycline, and eravacycline (with parenteral or oral formulations). In addition, sarecycline is very useful in treating acne vulgaris. Tetracyclines also have other non-antibiotic properties that require in-depth studies, such as the anti-inflammatory effect effect of sarecycline. The main side effects of modern tetracyclines are described in accordance with published clinical studies. Undoubtedly, this class of antibiotics continues to arouse the interest of researchers. As a result, new derivatives are developed and studied primarily for the antibiotic effect and other biological effects.

Molecular epidemiology & therapeutic options of carbapenem-resistant Gram-negative bacteria

Background & objectives:

The growing incidence and the wide diversity of carbapenemase-producing bacterial strains is a major concern as only a few antimicrobial agents are active on carbapenem-resistant bacteria. This study was designed to study molecular epidemiology of carbapenem-resistant Gram-negative bacterial (GNB) isolates from the community and hospital settings.

Methods:

In this study, non-duplicate GNB were isolated from clinical specimens, and phenotypic test such as modified Hodge test, metallo β-lactamase E-strip test, etc. were performed on carbapenem-resistant bacteria. Multiplex PCR was performed to identify the presence of bla_IMP, bla_VIM, bla_KPC, bla_OXA48, bla_OXA23, bla_SPM, bla_GIM, bla_SIM and bla_NDM. Minimum inhibitory concentration (MIC) of colistin, fosfomycin, minocycline, chloramphenicol and tigecycline was also determined.

Results:

Of the 3414 GNB studied, carbapenem resistance was 9.20 per cent and maximum resistance (11.2%) was present at tertiary care centre, followed by secondary care (4%) and primary centre (2.1%). Among the carbapenem-resistant bacteria, overall, the most common isolate was Pseudomonas aeruginosa (24%). On multiplex PCR 90.3 per cent carbapenem-resistant isolates were positive for carbapenemase gene. The bla_NDM (63%) was the most prevalent gene followed by bla_VIM (18.4%). MIC results showed that 88 per cent carbapenem-resistant Enterobacteriaceae were sensitive to fosfomycin, whereas 78 per cent of P. aeruginosa and 85 per cent Acinetobacter spp. were sensitive to colistin.

Interpretation & conclusions:

Carbapenem resistance in GNB isolates from the community and hospital settings was found to be on the rise and should be closely monitored. In the absence of new antibiotics in pipeline and limited therapeutic options, prudent use of antibiotics and strict infection control practices should be followed in hospital to limit the emergence and spread of multidrug-resistant bacteria.

Review for Analytical Methods for the Determination of Sodium Cephalothin

Infections are the second leading cause of global morbidity and mortality, therefore it is highly important to study the antimicrobial agents such as cephalosporins. Cephalothin, an antimicrobial agent that belongs to the class of cephalosporins, has bactericidal activity and it is widely used in the Brazilian health system. In literature, some analytical methods are found for the identification and quantification of this drug, which are essential for its quality control, which ensures maintaining the product characteristics, therapeutic efficacy and patient's safety. The aim of this article is to review the available information on analytical methods for cephalothin. Thus, this study presents a literature review on cephalothin and the analytical methods developed for the analysis of this drug in official and scientific papers. It is essential to note that most of the developed methods used toxic and hazardous solvents, which makes necessary industries and researchers choose to develop environmental-friendly techniques, which will contribute to the harmonization of science, human, and environmental health.

A Critical Review of Analytical Methods for Determination of Ceftriaxone Sodium

Ceftriaxone sodium is a third-generation semi-synthetic antibiotic belonging to the class of cephalosporins. Is administered only by parenteral route and has the ability to cross the blood-brain barrier. It has bactericidal action; its main activity is related to the Gram-negative bacteria, being also able to act against Gram-negative bacilli resistant to the first- and second-generation cephalosporins. The present study presents a survey of the characteristics, properties and analytical methods used for the determination of ceftriaxone sodium, for the gathering of data searches were carried out in scientific articles in the world literature, as well as in the official compendia. It is necessary to create awareness about the importance of developing effective and reliable analytical methods for quality control and consequently for conducting pharmacokinetic, bioavailability, bioequivalence studies as well as for the therapeutic monitoring of this drug. Most of the methods found use high-performance liquid chromatography, but also methods that use absorption spectroscopy ultraviolet, infrared spectroscopy, spectrofluorimetry and microbiological methods have been presented. A discussion was presented highlighting the need to develop new ecological methods using less toxic solvents, rapid analysis and miniaturization of the samples.

MMP-9, brain edema, and length of hospital stay of patients with spontaneous supratentorial intracerebral hemorrhage after hematoma evacuation along with the administration of tigecycline

Background: The high plasma level of matrix metalloproteinses–9 (MMP-9) is believed to disrupt the blood-brain barrier (BBB) and cause brain edema, as well as increase patient’s length of hospital stay (LOS). Tigecycline showed ability to reduce the MMP-9 level on study in animals. This study aimed to evaluate whether tigecycline can reduce the plasma levels of MMP-9; brain edema; and LOS of patients with supratentorial spontaneous intracerebral hemorrhage (SSICH).Methods: A randomized clinical trial (RCT) was conducted on 72 SSICH patients who underwent hematoma evacuation in eleven hospitals in Jakarta; 100 mg tigecycline (n=35) or 2 g fosfomycine (n=37) administered intravenously before skin incision as an prophylactic antibiotics to avoid post-operative infections. Plasma levels of MMP-9 were measured in all subjects before and on the first and seventh day after the surgery. Reduction of brain edema was assessed by comparing the extent of brain edema on computed tomography scan (CT scan) before and CT scan after surgery. The length of stay (LOS) was recorded at the time of hospital discharge either survive or death. Data were analyzed using Mann-Whitney and Chi-Square test.Results: There were non-significant statistical differences between two groups in the proportion of subjects with reduced MMP-9 levels on the first day (48% vs 50%; p=0.902; OR=1.1) and seventh day after the surgery (33% vs 48%; p=0.296; OR=1.9); proportion of the subjects with brain edema reduction (86% vs 80%, p=0.58); LOS (median 12 days vs 13 days, p=0.256; LOS ≥15 days 40% vs 27%; p=0.243; OR=1.81; NNT=8).Conclusion: On SSICH patients who underwent hematoma evacuation, tigecycline did not either reduce MMP-9 levels and brain edema or shorthen LOS.

Effects of tigecycline and doxycycline on inflammation and hemodynamics in porcine endotoxemia: a prospective, randomized, and placebo-controlled trial

Antibiotics might, apart from an antimicrobial effect, also exert anti-inflammatory effects. The novel antibiotic tigecycline, potentially useful in septic shock from gram-negative multiresistant bacteria, is structurally related to antibiotics with known anti-inflammatory properties. However, its anti-inflammatory effects have not been previously explored in vivo. Using a sterile integrative porcine sepsis model, we investigated the anti-inflammatory and circulatory effects of tigecycline in comparison with doxycycline and placebo. Eighteen pigs were randomized to receive tigecycline 100 mg, doxycycline 200 mg, or placebo and subjected to 6-h endotoxin infusion at 0.5 μg kg(-1) h(-1). Markers of inflammation, nitric oxide production, vascular permeability, hemodynamics, organ dysfunction, tissue metabolism, and acid-base parameters were monitored. Peak plasma tumor necrosis factor-α was lower in the doxycycline group (P = 0.031) but not in the tigecycline group (P = 0.86) compared with placebo, with geometric mean plasma concentrations of 16, 79, and 63 ng mL(-1), respectively. Mean arterial pressure was higher 4 to 6 h in the tigecycline group, with values at 6 h of 107 ± 9 mmHg compared with the placebo and doxycycline groups (85 ± 27 mmHg and 90 ± 32 mmHg, respectively; P = 0.025). The white blood cell and the neutrophil granulocyte counts were less reduced in the doxycycline group but not in the tigecycline group at 4 to 6 h (P = 0.009 and P = 0.019, respectively). Other markers of inflammation, organ dysfunction, tissue metabolism, and acid-base parameters were unaffected by tigecycline. Consistent with known anti-inflammatory properties, doxycycline yielded decreased tumor necrosis factor-α levels. Tigecycline did not affect cytokine levels but counteracted hypotension and hypoperfusion.

In vitro and in vivo anti-malarial activity of tigecycline, a glycylcycline antibiotic, in combination with chloroquine

BACKGROUND

Several antibiotics have shown promising anti-malarial effects and have been useful for malarial chemotherapy, particularly in combination with standard anti-malarial drugs. Tigecycline, a semi-synthetic derivative of minocycline with a unique and novel mechanism of action, is the first clinically available drug in a new class of glycylcycline antibiotics.

METHODS

Tigecycline was tested in vitro against chloroquine (CQ)-sensitive (D6) and resistant strains (W2) of Plasmodium falciparum alone and in combination with CQ. Tigecycline was also tested in vivo in combination with CQ in Plasmodium berghei-mouse malaria model for parasitaemia suppression, survival and cure of the malaria infection.

RESULTS

Tigecycline was significantly more active against CQ-resistant (W2) than CQ-susceptible (D6) strain of P. falciparum. Tigecycline potentiated the anti-malarial action of CQ against the CQ-resistant strain of P. falciparum by more than seven-fold. Further, treatment of mice infected with P. berghei with tigecycline (ip) produced significant suppression in parasitaemia development and also prolonged the mean survival time. Treatment with as low as 3.7 mg/kg dose of tigecycline, once daily for four days, produced 77-91% suppression in parasitaemia. In vivo treatment with tigecycline in combination with subcurative doses of CQ produced complete cure in P. berghei-infected mice.

CONCLUSION

Results indicate prominent anti-malarial action of tigecycline in vitro and in vivo in combination with CQ and support further evaluation of tigecycline as a potential combination candidate for treatment of drug-resistant cases of malaria.

Neutrophils engraftment delay during tigecycline treatment in 2 bone marrow-transplanted patients

BACKGROUND

Tigecycline is the first available drug of glycylcycline family. Because of recent introduction, some of its adverse effects could be still unexplored.

OBSERVATION

We report the cases of 2 boys who underwent an allogenic bone marrow transplantation for acute myeloid leukemia and were treated with tigecycline. Erythrocyte and platelet engraftment followed a normal course, but the neutrophil count remained low despite the increase in leukocyte count. After tigecycline interruption, the neutrophil count rapidly raised in both cases.

CONCLUSIONS

Neutropenia was suspected to be secondary to tigecycline exposure. In vitro experiments were performed, which suggested tigecycline influence on myeloid cells survival.

Antibiotic optimization in the difficult-to-treat patient with complicated intra-abdominal or complicated skin and skin structure infections: focus on tigecycline

Complicated intra-abdominal and skin and skin structure infections are widely varied in presentation. These infections very often lead to an increase in length of hospital stay, with a resulting increase in costs and mortality. In addition, these infections may be caused by a wide variety of bacteria and are often polymicrobial with the possibility of the presence of antimicrobial-resistant strains, such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum β-lactamase strains (Escherichia coli, Klebsiella pneumoniae), and K. pneumoniae carbapenemase-producing strains. In combination with patients’ immunosuppression or comorbidities, the treatment and management options for initial therapy success are few. Tigecycline, a new glycylcyline antimicrobial from the tetracycline drug class, represents a viable option for the successful treatment of these infections. It has been shown to have activity against a wide variety of bacteria, including the antimicrobial-resistant strains. As with all tetracycline drugs, it is not recommended for pregnant or nursing women. The potential side effects are those typical of tetracycline drugs: nausea, vomiting, and headaches. Drug–drug interactions are not expected, and renal function monitoring is not necessary.