List of new antibiotics approved since 2000

List of antibiotics,  since 2000:

 2000: Linezolid (Zyvox) — The first oxazolidinone, a new class effective against vancomycin-resistant enterococci (VRE) and MRSA.

2003: Daptomycin (Cubicin) — The first lipopeptide approved for skin and skin structure infections.

2005: Tigecycline (Tygacil) — First glycylcycline, a derivative of minocycline designed to overcome resistance. 

2010: Ceftaroline fosamil (Teflaro) — First cephalosporin with activity against MRSA.

2011: Fidaxomicin (Dificid) — A macrocyclic antibiotic for Clostridioides difficile.

2012: Bedaquiline (Sirturo) — First diarylquinoline for multi-drug resistant tuberculosis (MDR-TB).

2014: Dalbavancin (Dalvance) & Oritavancin (Orbactiv) — Lipoglycopeptides for acute bacterial skin and skin structure infections (ABSSSI).

2014: Tedizolid (Sivextro) — A second-generation oxazolidinone.

2014: Ceftolozane/tazobactam (Zerbaxa) — Cephalosporin/β-lactamase inhibitor combination.

2015: Ceftazidime/avibactam (Avycaz) — Novel β-lactamase inhibitor combination for serious Gram-negative infections.

2017: Meropenem/vaborbactam (Vabomere) — Combination targeting carbapenem-resistant Enterobacteriaceae (CRE).

2017: Delafloxacin (Baxdela) — An anionic fluoroquinolone with activity against MRSA.

2017: Ozenoxacin (Ozanex) — Topical quinolone.

2018: Plazomicin (Zemdri) — Next-generation aminoglycoside.

2018: Eravacycline (Xerava) — Novel synthetic fluorocycline.

2018: Omadacycline (Nuzyra) — Aminomethylcycline for pneumonia and skin infections.

2018: Sarecycline (Seysara) — Tetracycline for acne.

2019: Cefiderocol (Fetroja) — Siderophore cephalosporin for MDR Gram-negative infections.

2019: Lefamulin (Xenleta) — First systemic pleuromutilin for community-acquired pneumonia (CABP).

2019: Pretomanid — Nitroimidazole for extensively drug-resistant TB (XDR-TB)

 

The Threat: Microbes change over time, rendering drugs ineffective and leading to "superbugs".

Causes: Overuse of antibiotics for viral infections (like colds/flu), not finishing prescribed courses, and environmental contamination.

Prevention: Proper antimicrobial stewardship, including only using them when prescribed and practicing good hygiene to prevent infections.

 

 Thanks to Microbiology Matters for the list. 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

Meet the tiny ocean fungus that kills toxic algae

Algae, image by Tim Sandle
 

Scientists have discovered a newly identified marine fungus that can infect and kill toxic algae responsible for harmful blooms. The microscopic parasite, named Algophthora mediterranea, attacks algae such as Ostreopsis cf. ovata, which produces toxins that can irritate the lungs, skin, and eyes of people exposed during coastal blooms. Remarkably, the fungus can infect several different algae species and even survive on pollen, suggesting it is far more adaptable than most known marine parasites.

Researchers at Yokohama National University in Japan have identified a previously unknown species of marine fungus capable of killing harmful algae that form toxic blooms.

The organism, named Algophthora mediterranea, is a microscopic chytrid fungus that can infect a wide variety of hosts. Chytrids are a diverse group of aquatic fungi, and the discovery suggests they may influence marine ecosystems more strongly than scientists once believed.

The researchers found that this fungus acts as a lethal parasite in Ostreopsis cf. ovata, a species of algae responsible for toxic blooms that can negatively affect human health. The study describing the discovery was published in Mycologia.

Toxic Algae and Their Health Risks

Harmful algal blooms have become an increasing concern in oceans, rivers, and lakes around the world. These outbreaks occur when algae grow rapidly and excessively, often triggered by high nutrient levels and warmer water temperatures. Such blooms can degrade water quality, disrupt ecosystems, and release toxins that threaten both wildlife and people.

Large blooms of Ostreopsis cf. ovata have been reported more frequently in the Mediterranean over recent decades. This alga produces a toxin called ovatoxin (OVTX), which can cause symptoms in humans including runny nose, coughing, shortness of breath, conjunctivitis, itching, and dermatitis.

A Newly Identified Algae Killing Fungus

Algophthora mediterranea was first detected in Spanish seawater in 2021 by scientists from the Institut de Ciències del Mar (ICM) in Spain, led by Dr. E. Garcés and Dr. A. Reñé. The species was later formally described by Professor Maiko Kagami and PhD student Núria Pou-Solà at Yokohama National University.

Genetic analysis confirmed that the organism represents not only a newly identified species but also an entirely new genus. The researchers named the genus Algophthora by combining the word 'alga' with the Greek word 'phthora', meaning 'destruction'.

Scientists observed that the fungus parasitizes cells of O. cf. ovata and can kill them within a few days. Additional experiments showed that it can also infect several other algae species and can even feed on pollen grains.

Studying the Parasite in Detail

To better understand the organism, the researchers isolated the fungus and recorded time-lapse images every ten minutes over a four-day period. They also examined samples using scanning electron microscopy (SEM), a technique in which a focused beam of electrons scans the surface of a specimen to create highly detailed images. The fungus was also analyzed through DNA sampling.

Reference:

Núria Pou-Solà, Kensuke Seto, Alan Denis Fernández-Valero, Jordina Gordi, Esther Garcés, Albert Reñé, Maiko Kagami. Algophthora mediterranea , gen. et sp. nov.: Novel dinoflagellate- and diatom-infecting generalist marine chytrid from the Mediterranean Sea. Mycologia, 2025; 118 (1): 10 DOI: 10.1080/00275514.2025.2577604 

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

Microbiology information

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

Annual Cleanroom Design and Engineering for Life Science Networking Event

 

Annual Cleanroom Design and Engineering for Life Science Networking Event taking place on the 16-17 April in Zurich

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

New insights into antimicrobial tolerance

Antimicrobial tolerance is

the ability of a normally susceptible, often dormant, bacterial population to survive, rather than die, during extended exposure to bactericidal drugs without changing their minimum inhibitory concentration (MIC). Unlike resistance, which allows growth despite drugs, tolerant bacteria temporarily endure treatment, leading to chronic, relapsing infections and potential evolution into resistant strains. This represents an important area of inquiry for pharmaceutical microbiologists. 

 

The following video provides some insights, looking at recent research: 

 

 

 

Key Aspects of Antimicrobial Tolerance:

• Mechanism: Often involves low metabolic states (dormancy) or specialized stress responses (e.g., SOS DNA damage repair, cell envelope stress systems).
• Persistence vs. Tolerance: Tolerance typically describes the survival of the entire population, whereas persistence describes a small subpopulation ("persister cells") that survives high drug concentrations.
• Clinical Impact: Contributes to treatment failure in infections like tuberculosis, as bacteria "reawaken" once the antibiotic is removed.
• Distinction from Resistance: Tolerant cells do not grow in the presence of the drug, unlike resistant cells.
• Evolutionary Role: Tolerance can serve as a stepping stone for the development of full resistance.

Common Tolerance Mechanisms:

• Metabolic Slowdown: Reduced metabolic rate makes cells less susceptible to metabolic-dependent antibiotics.
• Biofilm Formation: Bacteria in biofilms often exhibit higher tolerance due to nutrient limitation and stress responses.
• Stress Responses: Activation of pathways (e.g., SOS response) that repair damage caused by antibiotics.

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

5,000 year old ice cave bacterium resists modern antibiotics

 Cave. Image by Tim Sandle

Bacteria are remarkably adaptable, thriving in some of the harshest places on Earth, from boiling hot springs to deep freezes far below zero. Ice caves are one such extreme habitat, home to diverse microorganisms that scientists are only beginning to understand. These frozen environments may contain vast stores of genetic material that have gone largely unexplored. 

Deep inside a Romanian ice cave, locked away in a 5,000-year-old layer of ice, scientists have uncovered a bacterium with a startling secret: it’s resistant to many modern antibiotics. Despite predating the antibiotic era, this cold-loving microbe carries more than 100 resistance-related genes and can survive drugs used today to treat serious infections like tuberculosis and UTIs.

Psychrobacter 

The Psychrobacter SC65A.3 bacterial strain isolated from Scarisoara Ice Cave, despite its ancient origin, shows resistance to multiple modern antibiotics and carries over 100 resistance-related genes.

The bacterium can also inhibit the growth of several major antibiotic-resistant 'superbugs' and shows important enzymatic activities with important biotechnological potential.

Psychrobacter SC65A.3 belongs to a group of cold-adapted bacteria known as Psychrobacter. While some members of this genus can cause infections in people or animals, they are also considered promising for biotechnology applications. Until now, however, little was known about how these bacteria respond to antibiotics. 

Studying microbes such as Psychrobacter SC65A.3 retrieved from millennia-old cave ice deposits reveals how antibiotic resistance evolved naturally in the environment, long before modern antibiotics were ever used.

How the organism was isolated 

To retrieve the organism, the team drilled a 25-meter ice core from a section of the cave called the Great Hall, capturing a frozen record spanning 13,000 years. To prevent contamination, ice samples were sealed in sterile bags and transported in frozen conditions back to the laboratory. There, scientists isolated bacterial strains and sequenced their genomes to identify genes responsible for surviving extreme cold, as well as genes linked to antimicrobial resistance and activity.

The researchers then tested SC65A.3 against 28 antibiotics across 10 different classes. These drugs are commonly prescribed or reserved for serious bacterial infections. Some had already been associated with known resistance genes or mutations, allowing the team to compare predicted resistance mechanisms with actual laboratory results. "The 10 antibiotics we found resistance to are widely used in oral and injectable therapies used to treat a range of serious bacterial infections in clinical practice," Purcarea noted. Among them were rifampicin, vancomycin, and ciprofloxacin, medications used to treat conditions such as tuberculosis, colitis, and UTIs.

SC65A.3 is the first Psychrobacter strain found to resist certain antibiotics, including trimethoprim, clindamycin, and metronidazole. These drugs are typically used to treat UTIs and infections affecting the lungs, skin, bloodstream, and reproductive system. The strain's resistance profile suggests that bacteria adapted to cold environments could serve as reservoirs of resistance genes, which are segments of DNA that enable survival when exposed to antibiotics.

Significance of the discovery 

Genetic analysis of Psychrobacter SC65A.3 revealed nearly 600 genes with unknown functions, pointing to a largely untapped resource for uncovering new biological processes. The team also identified 11 genes that may have the ability to kill or inhibit bacteria, fungi, and even viruses.

As antibiotic resistance continues to rise worldwide, insights from ancient microbes are becoming increasingly valuable. Studying genomes preserved in ice helps scientists trace how resistance emerged and spread long before modern medicine existed.

Research paper

Victoria Ioana Paun, Corina Itcus, Paris Lavin, Mariana Carmen Chifiriuc, Cristina Purcarea. First genome sequence and functional profiling of Psychrobacter SC65A.3 preserved in 5,000-year-old cave ice: insights into ancient resistome, antimicrobial potential, and enzymatic activities. Frontiers in Microbiology, 2026; 16 DOI: 10.3389/fmicb.2025.1713017 

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

Publications by Tim Sandle

 

Category	Number	Running total
Books*	41 (excluding new editions) 48 (with new additions)	41
Booklets and monographs	13	54
Book chapters**	120	174
Peer reviewed papers	236	410
White papers	17	425
Technical articles	637	1,047
University courses authored	15
Training packages	5
Commissioned reports and working papers	7
Written papers for conferences	14
Technical guides	15
Interviews (published)	35
Poster abstracts	1
Other published writing	21
Self-published industry aids	6

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)