In vitro susceptibility of Mycoplasma iowae isolates to antimicrobial agents.

ABSTRACTMycoplasma iowae, a potential re-emerging avian pathogen mainly affecting turkeys, has been reported from many parts of the world. Poor hatchability, embryonic death, joint and skeletal abnormalities, poor ossification, runting-stunting, poor feathering and airsacculitis may be observed in infected flocks. The reduction of the severity of clinical signs and short-term control of M. iowae are performed by antibiotic treatment. However, M. iowae develops resistance more rapidly and is considered to be more resistant to antimicrobials than other avian pathogenic mycoplasmas. The aim of the present study was to determine the in vitro susceptibility of 101 M. iowae isolates and strains to ten clinically important antimicrobial agents, and to analyse and compare the susceptibility patterns of isolates of various origins and from a wide time-period. The examined reference strains showed high susceptibility to all antimicrobials except for spectinomycin. Low concentrations of tiamulin, florfenicol and oxytetracycline inhibited the growth of the clinical isolates. Nevertheless, slow tendency of increasing minimum inhibitory concentration (MIC) values was observed over time in the case of the above mentioned agents, while MIC values of enrofloxacin showed relatively rapid changes. Spiramycin, erythromycin, tilmicosin, tylosin, lincomycin and spectinomycin did not inhibit the bacterial growth in most of the cases. Isolates originating from captive game birds showed similar susceptibility profiles to isolates from industrial turkey hosts. The widely detected low susceptibility of M. iowae isolates to macrolides, lincomycin and spectinomycin, and the increase of MIC values of frequently used antimicrobials against this pathogen, emphasize the importance of targeted antibiotic therapy.RESEARCH HIGHLIGHTSAntimicrobial susceptibilities of 101 Mycoplasma iowae isolates were determined.Minimum inhibitory concentrations were determined by broth micro-dilution method.Tiamulin, oxytetracycline and florfenicol showed low MIC values.Isolates rapidly adapted to antimicrobial pressure.

Patterns and predictors of antimicrobial resistance among Staphylococcus spp. from canine clinical cases presented at a veterinary academic hospital in South Africa.

BACKGROUND: Antimicrobial resistance in staphylococci, often associated with treatment failure, is increasingly reported in veterinary medicine. The aim of this study was to investigate patterns and predictors of antimicrobial resistance among Staphylococcus spp. isolates from canine samples submitted to the bacteriology laboratory at the University of Pretoria academic veterinary hospital between 2007 and 2012. Retrospective data of 334 Staphylococcus isolates were used to calculate the proportion of samples resistant to 15 antimicrobial agents. The Cochran-Armitage trend test was used to investigate temporal trends and logistic regression models were used to investigate predictors of antimicrobial resistance in Staphylococcus aureus and Staphylococcus pseudintermedius. RESULTS: Results show that 98.2% (55/56) of the S. aureus isolates were resistant to at least one drug while 42.9% were multidrug resistant. Seventy-seven percent (214/278) of the S. pseudintermedius isolates were resistant to at least one drug and 25.9% (72/278) were multidrug resistant. Resistance to lincospectin was more common among S. aureus (64.3%) than S. pseudintermedius (38.9%). Similarly, resistance to clindamycin was higher in S. aureus (51.8%) than S. pseudintermedius (31.7%) isolates. There was a significant (p = 0.005) increase in S. aureus resistance to enrofloxacin over the study period. Similarly, S. pseudintermedius exhibited significant increasing temporal trend in resistance to trimethoprim-sulphamethoxazole (p = 0.004), clindamycin (p = 0.022) and orbifloxacin (p = 0.042). However, there was a significant decreasing temporal trend in the proportion of isolates resistant to doxycycline (p = 0.041), tylosin (p = 0.008), kanamycin (p = 0.017) and amoxicillin/clavulanic acid (p = 0.032). CONCLUSIONS: High levels of multidrug resistance and the increasing levels of resistance to sulphonamides, lincosamides and fluoroquinolones among Staphylococcus spp. isolates in this study are concerning. Future studies will need to investigate local drivers of antimicrobial resistance to better guide control efforts to address the problem.

Treatment rates for injectable tiamulin and lincomycin as an estimate of morbidity in a swine herd with endemic swine dysentery.

Treatment can be used as an indirect measure of morbidity, and treatment records can be used to describe disease patterns in a population. The aim of this study was to describe the rates of treatments with tiamulin and lincomycin by the intramuscular route in cohorts of pigs affected by swine dysentery. Data from treatment records from 19 cohorts of a 1500-head grower-finisher barn were analyzed using Poisson regression to determine factors associated with rates of treatment. Serial interval and reproductive numbers were extracted. Treatment rates displayed marked seasonality. The mean serial interval was estimated at 17 d with variability among batches. In the early period of most cohorts, the effective reproductive number did not exceed 1, and the highest estimate was 2.15 (95% CI: 1.46, 3.20). The average days-to-first treatment was 4.8 which suggests that pigs could have been infected at time of entry. The information about possible sources of infection and likely seasonality should be considered when developing disease and infection control measures in affected barns.

Taux de traitement pour la tiamuline et la lincomycine injectables en tant qu'estimation de la morbidité dans un troupeau porcin atteint de dysenterie porcine. Le traitement peut servir de mesure indirecte de la morbidité et les dossiers de traitement peuvent être utilisés pour décrire les profils pathologiques au sein d'une population. Le but de cette étude consistait à décrire les taux de traitement à l'aide de la tiamuline et de la lincomycine par voie intramusculaire dans des cohortes de porcs affectées par la dysenterie porcine. Les données des dossiers de traitement provenant de 19 cohortes d'une porcherie de 1500 porcs d'engraissement ont été analysées en utilisant la régression de Poisson pour déterminer les facteurs associés aux taux de traitement. Des données sur les intervalles sériels et la reproduction ont été extraites. Les taux de traitement ont affiché une saisonnalité marquée. L'intervalle sériel moyen était estimé à 17 jours avec de la variabilité entre les groupes. Au début de la période de la plupart des cohortes, le nombre effectif de reproductions n'a pas dépassé 1 et l'estimation la plus élevée était de 2,15 (IC de 95 % : 1,46, 3,20). Le nombre moyen avant le premier traitement était de 4,8 jours, ce qui suggère que les porcs auraient pu être infectés au moment de l'arrivée. Les renseignements sur les sources possibles d'infection et la saisonnalité probable devraient être considérés lors de l'élaboration de mesures de contrôle de la maladie et de l'infection dans les porcheries affectées.(Traduit par Isabelle Vallières).

[THE MOLECULAR GENETIC CHARACTERISTIC OF SPECIES CONTENT OF SALIVA AND GINGIVAL RECESS UNDER PERIODONTITIS].

The examination was carried out of samplings of 110 patients with periodontitis (observation group) and 60 patients without pathology of periodont (comparison group). The polymerase chain reaction was used to analyze samples of saliva and contents of periodontal recesses for detecting species-specific DNA fragments of Porphymmonas gigngivalis, Streptococcus macacae, S. mutans, S. oralis, S. salivarius, S. sangis, S. sobrinus, Treponema denticola. In patients with periodontitis S. mutans, S. oralis S. sobrinus were reliably more often detected in the content of periodontal recesses and S. mutans, S. sobrinus i in saliva. In the observation group the rate of detection of association S. mutans--S. oralis--S. sangis--S. sobrinus was significantly exceeded (up to 15.6%, X2 = 9.1, p = 0.004). In ten days of effective treatment of periodontitis reliable decreastng of rate of detection of S. wasoralis, S. sobrinus was observed in contents of periodontal recesses but not in of saliva. The detection of S.sobrinus using technique of polymerase chain reaction in contents of periodontal recesses and/or saliva of patients with periodontitis has a diagnostic value. The detection of S.sobrinus in contents of periodontal recesses is significant both in monoculture and in association S. mutans--S. oralis--S. sangis--S.sobrinus. The absence of S. sobrinus in contents of periodontal recesses testifies effectiveness of treatment of main disease (periodontitis).

Synergistic approach for acne vulgaris treatment using glycerosomes loaded with lincomycin and lauric acid: Formulation, in silico, in vitro, LC-MS/MS skin deposition assay and in vivo evaluation.

This study aims to develop a pharmaceutical formulation that combines the potent antibacterial effect of lincomycin and lauric acid against Cutibacterium acnes (C. acnes), a bacterium implicated in acne. The selection of lauric acid was based on an in silico study, which suggested that its interaction with specific protein targets of C. acnes may contribute to its synergistic antibacterial and anti-inflammatory effects. To achieve our aim, glycerosomes were fabricated with the incorporation of lauric acid as a main constituent of glycerosomes vesicular membrane along with cholesterol and phospholipon 90H, while lincomycin was entrapped within the aqueous cavities. Glycerol is expected to enhance the cutaneous absorption of the active moieties via hydrating the skin. Optimization of lincomycin-loaded glycerosomes (LM-GSs) was conducted using a mixed factorial experimental design. The optimized formulation; LM-GS4 composed of equal ratios of cholesterol:phospholipon90H:Lauric acid, demonstrated a size of 490 ± 17.5 nm, entrapment efficiency-values of 90 ± 1.4 % for lincomycin, and97 ± 0.2 % for lauric acid, and a surface charge of -30.2 ± 0.5mV. To facilitate its application on the skin, the optimized formulation was incorporated into a carbopol hydrogel. The formed hydrogel exhibited a pH value of 5.95 ± 0.03 characteristic of pH-balanced skincare and a shear-thinning non-Newtonian pseudoplastic flow. Skin deposition of lincomycin was assessed using an in-house developed and validated LC-MS/MS method employing gradient elution and electrospray ionization detection. Results revealed that LM-GS4 hydrogel exhibited a two-fold increase in skin deposition of lincomycin compared to lincomycin hydrogel, indicating improved skin penetration and sustained release. The synergistic healing effect of LM-GS4 was evidenced by a reduction in inflammation, bacterial load, and improved histopathological changes in an acne mouse model. In conclusion, the proposed formulation demonstrated promising potential as a topical treatment for acne. It effectively enhanced the cutaneous absorption of lincomycin, exhibited favorable physical properties, and synergistic antibacterial and healing effects. This study provides valuable insights for the development of an effective therapeutic approach for acne management.

Network meta-analysis of the therapeutic effects of various antibiotics on footrot in sheep and cattle.

The present network meta-analysis was performed to compare the effects of antibiotics used in treating footrot in some ruminants and to rank these antibiotics based on their efficacy. Data of 14 eligible studies consisting of 5622 affected animals was included in the analysis. A Bayesian method and Markov Chain Monte Carlo (MCMC) simulations were utilized to analyze data. The estimated results were reported in the form of odds ratios (ORs) with 95% credible intervals (CrI). The Surface Under the Cumulative Ranking Curve (SUCRA) was used to rank antibiotics. Network meta-regressions (NMRs) were conducted to examine the influence of sample sizes, treatment duration, route of administration, and species of animals (sheep and cattle) on the overall outcome. The results indicated that gamithromycin impact on curing footrot was superior to other antibiotics and Lincomycin and oxytetracycline were ranked second and third. The difference between the impact of gamithromycin and amoxicillin (OR = 14.76, CrI: 1.07-193.49) and enrofloxacin (OR = 20.21, CrI: 1.57-229.25) on footrot was significant. There was a significant difference between the effect of oxytetracycline and enrofloxacin (OR = 5.24, CrI: 1.14-23.74) on footrot. The NMR performed based on species of animals fitted data better than network meta-analysis, suggesting erythromycin as the best third antibiotic instead of oxytetracycline. Egger's regression test and the shape of the funnel plot showed no publication bias among included studies. In conclusion, gamithromycin was associated with the highest curing rate benefit when used to treat footrot, followed by lincomycin and oxytetracycline/erythromycin. Among all evaluated antibiotics, enrofloxacin showed the lowest effects on footrot.

Panax quinquefolius Polysaccharides Ameliorate Antibiotic-Associated Diarrhoea Induced by Lincomycin Hydrochloride in Rats via the MAPK Signaling Pathways.

American ginseng (Panax quinquefolius L.) is an herbal medicine with polysaccharides as its important active ingredient. The purpose of this research was to identify the effects of the polysaccharides of P. quinquefolius (WQP) on rats with antibiotic-associated diarrhoea (AAD) induced by lincomycin hydrochloride. WQP was primarily composed of galacturonic acid, glucose, galactose, and arabinose. The yield, total sugar content, uronic acid content, and protein content were 6.71%, 85.2%, 31.9%, and 2.1%, respectively. WQP reduced the infiltration of inflammatory cells into the ileum and colon, reduced the IL-1ß, IL-6, IL-17A, and TNF-α levels, increased the levels of IL-4 and IL-10 in colon tissues, improved the production of acetate and propionate, regulated the gut microbiota diversity and composition, improved the relative richness of Lactobacillus and Bacteroides, and reduced the relative richness of Blautia and Coprococcus. The results indicated that WQP can enhance the recovery of the intestinal structure in rats, reduce inflammatory cytokine levels, improve short-chain fatty acid (SCFA) levels, promote recovery of the gut microbiota and intestinal mucosal barrier, and alleviate antibiotic-related side effects such as diarrhoea and microbiota dysbiosis caused by lincomycin hydrochloride. We found that WQP can protect the intestinal barrier by increasing Occludin and Claudin-1 expression. In addition, WQP inhibited the MAPK inflammatory signaling pathway to improve the inflammatory status. This study provides a foundation for the treatment of natural polysaccharides to reduce antibiotic-related side effects.

Short Chain Fatty Acids (SCFAs) Are the Potential Immunomodulatory Metabolites in Controlling Staphylococcus aureus-Mediated Mastitis.

Mastitis is an emerging health concern in animals. An increased incidence of mastitis in dairy cows has been reported in the last few years across the world. It is estimated that up to 20% of cows are suffering from mastitis, causing incompetency in the mucosal immunity and resulting in excessive global economic losses in the dairy industry. Staphylococcus aureus (S. aureus) has been reported as the most common bacterial pathogen of mastitis at clinical and sub-clinical levels. Antibiotics, including penicillin, macrolides, lincomycin, cephalosporins, tetracyclines, chloramphenicol, and methicillin, were used to cure S. aureus-induced mastitis. However, S. aureus is resistant to most antibiotics, and methicillin-resistant S. aureus (MRSA) especially has emerged as a critical health concern. MRSA impairs immune homeostasis leaving the host more susceptible to other infections. Thus, exploring an alternative to antibiotics has become an immediate requirement of the current decade. Short chain fatty acids (SCFAs) are the potent bioactive metabolites produced by host gut microbiota through fermentation and play a crucial role in host/pathogen interaction and could be applied as a potential therapeutic agent against mastitis. The purpose of this review is to summarize the potential mechanism by which SCFAs alleviate mastitis, providing the theoretical reference for the usage of SCFAs in preventing or curing mastitis.

[Methodic approaches to treatment of the chronic generalized parodontitis in elderly and senile patients].

A comprehensive treatment with Likopid of chronic generalized parodontitis in 114 elderly and senile patients was carried out. The state of mechanisms of innate immunity (phagocytosis mechanisms) as well as the profile of proinflammatory cytokines was assessed. The effect of antibiotic-resistant strains of prior microflora on the combined therapy of patients of different age with chronic generalized parodontitis was studied. It is established that due to presence of various types of opportunistic pathogens in patients of different age with parodontitis using the prophylactic antibiotics for the empirical (to determine the antibiotic resistance), a combination of Metronidazole and Lincomycin with the mandatory appointment of immunomodulatory drugs for activation of monocyte-phagocytic system of the patient elderly is most advisable. Use of the drug , "Likopid" significantly improves the results of treatment the elderly and old patients with chronic generalized parodonthitis.

Clinical, histologic, and bacteriologic findings in dairy cows with digital dermatitis (footwarts) one month after topical treatment with lincomycin hydrochloride or oxytetracycline hydrochloride.

OBJECTIVE: To compare the effectiveness of lincomycin and oxytetracycline for treatment of digital dermatitis (DD) in dairy cows through gross visual examination, histologic evaluation, and bacteriologic evaluation. DESIGN: Randomized controlled clinical trial. ANIMALS: 25 cows with DD lesions from a commercial Holstein dairy herd. PROCEDURES: Cows with DD lesions were randomly assigned to 1 of 3 groups: topical treatment with 10 g of lincomycin hydrochloride (n = 11), topical treatment with 10 g of oxytetracycline hydrochloride (11), and no treatment (3) on days 1 and 2 (d1). Biopsy specimens were obtained for histologic examination from DD lesions prior to treatment and 28 or 31 days (d30) after treatment for histologic examination. Cows were clinically examined on d1, days 12 or 14 (d14), and d30. RESULTS: No difference was evident in clinical responses to lincomycin and oxytetracycline, so data were pooled; at d30, 8 of 11 of lincomycin-treated lesions and 7 of 11 oxytetracycline-treated lesions appeared visually healed, respectively. Gross visual examination suggested 73% (16/22) of treated cows were healed at d14 and 68% (15/22) of treated cows were healed on d30. Of the 15 lesions that appeared healed on d30, 7 of 15 were classified histologically as active (ulceration and bacterial invasion; 2/15) or incipient (5/15). CONCLUSIONS AND CLINICAL RELEVANCE: Clinical responses to lincomycin and oxytetracycline did not differ. Agreement was good between gross visual and histologic assessments of DD lesions before treatment; agreement 1 month after treatment was variable. Histologic evaluation could not distinguish incomplete healing from lesion recurrence.

Antibiotic prescription for the treatment of endodontic pathology: a survey among Lithuanian dentists.

OBJECTIVE: To describe a pattern of antibiotic prescription during root canal treatment procedures based on the reports of Lithuanian general dental practitioners. MATERIALS AND METHODS: Questionnaires concerning endodontic treatment were sent to all 2850 Lithuanian dental practitioners registered on the database of the Lithuanian Dental Chamber. Only the questions containing general information and individual decisions about antibiotic prescription for endodontic treatment were selected for the analysis. RESULTS: The response rate was 53.8%. Of the 1532 responses, 1431 questionnaires received from licensed general dental practitioners were analyzed. More than 60% of the respondents reported prescribing antibiotics in cases of symptomatic apical periodontitis. Majority of the respondents (83.9%) reported symptomatic apical periodontitis with periostitis being a clear indication for the prescription of antibiotics. Nearly 2% of the respondents reported prescribing antibiotics in cases of symptomatic pulpitis. With an increasing duration of professional activity, an increase in the proportion of the respondents reporting prescription of antibiotics was observed. Amoxicillin was the most preferable antibiotic during endodontic treatment, followed by amoxicillin with clavulanic acid. An increase in reporting penicillin prescription and decline in prescribing amoxicillin and amoxicillin with clavulanic acid with regard to the increasing age of respondents was observed. CONCLUSIONS: Lithuanian dentists, particularly those with longer duration of professional activity, tended to exceed general recommendations for the antibiotics prescription in cases of endodontic infections. However, a trend toward prescription of broader spectrum antibiotics by younger dentists, compared with those with longer professional activity, was observed.

[Use of KollapAn L in cases of maxilla alveolar ridge trauma].

Results of research have shown, that application КоllаpАn L at the fracture site of an alveolar ridge of upper jaw raises efficiency of treatment and reduces complications up to 20%.

WITHDRAWN: The comparison of the effectiveness of lincocin® and azitro® in the treatment of covid-19-associated pneumonia: A prospective study.

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Post operative penicillin-non-susceptible Streptococcus pneumoniae meningitis and septic shock in a child.

The authors describe a one-year-old girl with a fronto-ethmoidal encephalomeningocele who developed wound infection, purulent meningitis and septic shock 5 hours after operation. The patient was treated with intravenous ceftazidime and vancomycin empirically. The cerebrospinal fluid (CSF) and eye discharge grew Streptococcus pneumoniae (S. pneumoniae). The minimal inhibitory concentration (MIC) by E-test of penicillin and cefotaxime were 1.0 and 0.38 ug/ml respectively so the antibiotics were switched to cefotaxime 300 mg/kg/day. She recovered completely after appropriate treatment. Penicillin-non-susceptible S. pneumoniae should be considered as one of the causes of post-operative serious infection of the face and neck in the era of increasing prevalence of penicillin-resistant S. pneumoniae.

Case Report: Fatal Pediatric Melioidosis Despite Optimal Intensive Care.

With prompt administration of appropriate antimicrobial therapy and access to modern intensive care support, fatal pediatric melioidosis is very unusual. We describe cases of two children in whom the possibility of melioidosis was recognized relatively early, but who died of the disease, despite receiving optimal supportive care. We discuss the resulting implications for bacterial virulence factors in disease pathogenesis.

Management of diabetic foot in a Jordanian hospital.

The effect of different antibiotics on the outcome of surgical care in the management of diabetic foot was investigated. We randomly allocated 100 patients with diabetic foot into one of four groups. Each patient's infection was graded (Wagner classification). All patients were offered the same surgical care but each group was assigned a different antibiotic. Hospital stay for the four groups ranged from 7 to 14 days. Five patients experienced complications from septicaemia; 15 patients underwent amputation; and five patients experienced temporary renal impairment. Careful consideration to the type of antibiotic used is essential.

Q fever endocarditis.

Despite a worldwide distribution of Coxiella burnetii, only single cases of Q fever endocarditis have been reported outside Great Britain and Australia. We present 10 patients; five were female, only four had a history of environmental exposure, and the mitral valve was involved as commonly as the aortic stenosis, and three patients had a prosthetic valve. We confirm the importance of hepatic involvement, thrombocytopenia and hypergammaglobulinemia as diagnostic features. Diagnosis was established by finding and elevated complement-fixing antibody to Phase I C. burnetii antigen. Tetracycline, with or without lincomycin or cotrimoxazole, was used in nine patients, and one patient received cotrimoxazole as as the sole antibiotic agent. Optimal duration of therapy is unknown. In one patient, relapse followed when treatment was stopped after 18 months. Valve replacement was necessary in five patients, because of hemodynamic problems. Five patients died, and the means survival is 36 months with a range of five to 66 months. We suggest that Q fever endocarditis is frequently missed, and we recommend clinicians to consider the diagnosis in all cases of culture-negative endocarditis.

Adverse reactions to parenteral lincomycin.

Lincomycin use has not been reported exclusively in children and inasmuch as it has been extensively used at our institution, a chart review of 265 patients who received parenteral lincomycin at a dose of 100 mg/kg/day in four divided doses for five days or longer was undertaken. The following conditions were diagnosed: cellulitis, 39%; septic arthritis, 21%; osteomyelitis, 16%; abscess, 13%; lymphadenitis, 9%; and pneumonia, 1%. Cures were achieved in all. The majority of organisms cultured were Staphylococcus aureus and Streptococcus pyogenes. Duration of therapy ranged from five to 63 days, with a mean of 15 days. The lincomycin dose ranged from 75 to 2,400 mg every six hours. The majority of patients received the drug intravenously, but 25.7% received it only intramuscularly. There were no adverse reactions at the administration sites. Only 3% of the patients developed diarrhea, which was not felt to be secondary to the drug. There were no cases of pseudomembranous colitis. Therefore parenteral lincomycin in children appears to be a safe and effective antibiotic when used for infections due to Gram-positive cocci.

Antimicrobial drugs used in the management of anaerobic infections in children.

Optimum antimicrobial therapy effective against anaerobes is required to rapidly resolve infections due to these organisms and to prevent serious complications. Selection of antimicrobial therapy should be based on clinical experience and presumptive evidence until culture and sensitivity tests are available. If an abscess should develop, surgical drainage (when possible) is of paramount importance. Antimicrobial therapy for anaerobic infections should usually be given for prolonged periods because of the tendency for relapse, and should include coverage for aerobic bacteria whenever they are present. Penicillin G remains the drug of choice for most anaerobic infections except those caused by beta-lactamase-producing Bacteroides spp. such as B. fragilis and B. melaninogenicus, and some strains of Fusobacterium varium, which can be resistant. Other antimicrobials which are available for treatment of anaerobic infections in paediatric patients, and are generally active against B. fragilis, are carbenicillin, ticarcillin, chloramphenicol, clindamycin and cefoxitin. Experience in the use of metronidazole suggests that it could be a very valuable antimicrobial agent in the treatment of anaerobic infections. Experience with synergistic antimicrobial combinations in the treatment of anaerobic infections is limited; only experimental data are available suggesting synergism between penicillin and aminoglycosides against some Bacteroides spp. beta-Lactamase-producing anaerobic bacteria may protect other penicillin-susceptible bacteria in mixed infections. This phenomenon may explain penicillin failure in eradicating mixed infections.

Intraocular penetration of topically applied lincomycin hydrochloride in rabbits.

Ocular penetration of lincomycin hydrochloride in albino rabbits was determined by bioassay. On topical application, the frequency of multiple instillation of drops played an important role in producing therapeutic levels in the anterior chambers. Therapeutic levels were attained in the cornea, aqueous humor, and iris-ciliary body, with peak values occurring at 30 to 45 minutes. Varying the pH of the dosing solution did not change ocular absorption and distribution substantially. Removal of corneal epithelium, however, greatly enhanced absorption. Relative to clindamycin, lincomycin hydrochloride had longer onset of peak values and lower overall concentration in ocular tissues. Intravitreous injection of lincomycin hydrochloride produced therapeutic and steady levels of antibiotic in anterior chambers. Injection produced a concentration in aqueous humor twice that achievable topically. The major route of elimination from the posterior chamber was through retina-choroid.