Neutralization of the Staphylococcus aureus Panton-Valentine leukocidin by African and Caucasian sera

Background

The prevalence of Staphylococcus aureus isolates carrying the Panton-Valentine leukocidin (PVL) gene is higher in Africa (≈50%) compared to Europe (< 5%). The study aimed to measure anti-PVL-antibodies in Africans and Germans in a multi-center study and to test whether detected antibodies can neutralize the cytotoxic effect of PVL on polymorphonuclear leukocytes (PMNs).

Methods

Sera from asymptomatic Africans (n = 22, Nigeria, Gabon) and Caucasians (n = 22, Germany) were used to quantify antibody titers against PVL and α-hemolysin (in arbitrary units [AU]) by ELISA. PMNs from one African and German donor were exposed to 5 nM recombinant PVL to measure the neutralizing effect of serial dilutions of pooled sera from African and Caucasian participants, or donor sera at 0.625 and 2.5% (v/v).

Results

Anti-PVL-antibodies were significantly higher in Africans than in Germans (1.9 vs. 0.7 AU, p < 0.0001). The pooled sera from the study participants neutralized the cytotoxic effect of PVL on African and German PMNs in a dose dependent manner. Also, neutralization of PVL on PMNs from the African and German donors had a stronger effect with African sera (half-maximal inhibitory concentration (IC50) = 0.27 and 0.47%, respectively) compared to Caucasian sera (IC50 = 3.51 and 3.59% respectively).

Conclusion

Africans have higher levels of neutralizing anti-PVL-antibodies. It remains unclear if or at what level these antibodies protect against PVL-related diseases.

A 6-Year Update on the Diversity of Methicillin-Resistant Staphylococcus aureus Clones in Africa: A Systematic Review

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of hospital-associated (HA) and community-associated (CA) infections globally. The multi-drug resistant nature of this pathogen and its capacity to cause outbreaks in hospital and community settings highlight the need for effective interventions, including its surveillance for prevention and control. This study provides an update on the clonal distribution of MRSA in Africa.

Methods

A systematic review was conducted by screening for eligible English, French, and Arabic articles from November 2014 to December 2020, using six electronic databases (PubMed, EBSCOhost, Web of Science, Scopus, African Journals Online, and Google Scholar). Data were retrieved and analyzed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines (registered at PROSPERO: CRD42021277238). Genotyping data was based primarily on multilocus sequence types (STs) and Staphylococcal Cassette Chromosome mec (SCCmec) types. We utilized the Phyloviz algorithm in the cluster analysis and categorization of the MRSA STs into various clonal complexes (CCs).

Results

We identified 65 studies and 26 publications from 16 of 54 (30%) African countries that provided sufficient genotyping data. MRSA with diverse staphylococcal protein A (spa) and SCCmec types in CC5 and CC8 were reported across the continent. The ST5-IV [2B] and ST8-IV [2B] were dominant clones in Angola and the Democratic Republic of Congo (DRC), respectively. Also, ST88-IV [2B] was widely distributed across the continent, particularly in three Portuguese-speaking countries (Angola, Cape Verde, and São Tomé and Príncipe). The ST80-IV [2B] was described in Algeria and Egypt, while the HA-ST239/ST241-III [3A] was only identified in Egypt, Ghana, Kenya, and South Africa. ST152-MRSA was documented in the DRC, Kenya, Nigeria, and South Africa. Panton-Valentine leukocidin (PVL)-positive MRSA was observed in several CCs across the continent. The median prevalence of PVL-positive MRSA was 33% (ranged from 0 to 77%; n = 15).

Conclusion

We observed an increase in the distribution of ST1, ST22, and ST152, but a decline of ST239/241 in Africa. Data on MRSA clones in Africa is still limited. There is a need to strengthen genomic surveillance capacity based on a "One-Health" strategy to prevent and control MRSA in Africa.

First Report of a Methicillin-Resistant, High-Level Mupirocin-Resistant Staphylococcus argenteus

We describe the identification of a methicillin-resistant, high-level mupirocin-resistant Staphylococcus argenteus. The isolate (1801221) was characterized as t6675-ST2250-SCCmecIVc, and whole-genome sequencing revealed that the isolate possessed two plasmids. One plasmid (34,870 bp), designated p1_1801221 with rep23, harboured the mupirocin resistance (mupA) gene. The second plasmid (20,644 bp), assigned as p2_1801221 with rep5a and rep16, carried the resistance determinants for penicillin (blaZ) and cadmium (cadD). Phylogenetic analysis revealed that the isolate clustered with the European ST2250 lineage. The overall high similarity of both plasmids in S. argenteus with published DNA sequences of Staphylococcus aureus plasmids strongly suggests an interspecies transfer. The pathogenic potential, community and nosocomial spread, and acquisition of antibiotic resistance gene determinants, including the mupA gene by S. argenteus, highlight its clinical significance and the need for its correct identification.

Genomic analysis of Staphylococcus aureus from the West African Dwarf (WAD) goat in Nigeria

Background

Staphylococcus aureus can colonize various host species, and human-animal interaction is a significant factor for cross-species transmission. However, data on S. aureus colonization in animals, particularly on ruminants in close contact with humans, is limited. The West African Dwarf (WAD) goat is among the earliest domesticated ruminant associated with rural dwellers and small-holder farmers in sub-Saharan Africa. This study aimed to investigate the population structure, antibiotic resistance, and virulence gene determinants of S. aureus from the WAD goat in Nigeria.

Methods

Nasal samples were obtained from the WAD goat in five markets in Osun State, South-West Nigeria. S. aureus was characterized by antibiotic susceptibility testing, detection of virulence determinants, spa typing, and multilocus sequence typing (MLST). Representative isolates were selected for whole-genome sequencing, biofilm, and cytotoxicity assay.

Results

Of the 726 nasal samples obtained from the WAD goat, 90 S. aureus (12.4%) were recovered. Overall, 86 isolates were methicillin-susceptible, and four were mecA-positive (i.e., methicillin-resistant S. aureus [MRSA]). A diverse S. aureus clonal population was observed (20 sequence types [STs] and 37 spa types), while 35% (13/37) and 40% (8/20) were new spa types and STs, respectively. Eleven MLST clonal complexes (CC) were identified (CC1, CC5, CC8, CC15, CC30, CC45, CC97, CC121, CC133, CC152, CC522). The MRSA isolates were designated as t127-ST852-CC1-SCCmec type VII, t4690-ST152-CC152-SCCmec type Vc, and t8821-ST152-CC152-SCCmec type Vc. Phylogenetic analysis revealed that 60% (54/90) of all isolates were associated with ruminant lineages (i.e., CC133, CC522). Panton-Valentine Leukocidin (PVL)-positive S. aureus was identified in CC1, CC30, CC121, and CC152. For the CC522 isolates, we illustrate their pathogenic potential by the detection of the toxic shock syndrome gene and hemolysins, as well as their strong cytotoxicity and ability to form biofilms.

Conclusions

This is the first detailed investigation on the genomic content of S. aureus from the WAD goat in Nigeria. The S. aureus population of the WAD goat consists mainly of ruminant-associated lineages (e.g., CC133, CC522), interspersed with human-associated clones, including PVL-positive MRSA CC1 and CC152.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-021-00987-8.

Antibiotic-resistant staphylococci from the wastewater treatment plant and grey-water samples in Obafemi Awolowo University, Ile-Ife, Nigeria

This study examined the occurrence and molecular basis for antibiotic-resistant staphylococci from the wastewater treatment plant and grey-water samples in Obafemi Awolowo University, Nigeria. Standard microbiological techniques and molecular methods were utilized. The species identified (MALDI score >1.7) comprised S. saprophyticus (19), S. cohnii (8), S. sciuri (7), S. aureus (4), S. epidermidis (3), S. warneri (2), S. equorum (1), S. haemolyticus (1), S. nepalensis (1), S. condimenti (1), and S. pasteuri (1). Resistance to trimethoprim, tetracycline and cefoxitin were observed in 78.3% (47/60), 36.7% (22/60) and 25% (15/60) of the isolates, respectively. The rate of multidrug resistance was 53.3% (32/60) and observed in eight species from different sampling sites. Seven (S. sciuri; n = 5; S. aureus; n = 1; S. warneri; n = 1) of the 20 selected (representing the various staphylococcal species and antibiotypes) isolates were mecA-positive. Furthermore, the tetK gene was detected in nine isolates, six with dfrA, and four were positive for the dfrG gene. One S. aureus was mecA, tetK and dfrG gene positive. The study provides insights on antibiotic-resistant staphylococci from a non-clinical setting and highlights the need for active surveillance to understand the burden of antimicrobial resistance in Nigeria. This is key to improve synergy across the human, animal and environmental health sectors in Nigeria.

Molecular characterization of Staphylococcus aureus complex from fomites in Nigeria

Fomites serve as a potential route for the transmission of pathogens including community-acquired methicillin-resistant Staphylococcus aureus to humans. Phylogenetic and taxonomic analyses have established the Staphylococcus aureus complex (S. aureus, S. argenteus and S. schweitzeri), however, phenotypic characteristics are insufficient in the delineation of these species. In this study, we describe the S. aureus complex from inanimate surfaces in Nigeria. Fomite samples in Obafemi Awolowo University were initially screened for S. aureus and species differentiation was determined by MALDI-TOF, PCR of the S. aureus specific thermonuclease and the nonribosomal peptide synthetase genes. Characterization of the isolates was based on antimicrobial susceptibility, spa typing, multilocus sequence typing and virulence gene detection (lukS/lukF-PV, chp, sak, scn). Whole-genome sequencing was done for selected isolates. Of the 239 fomites samples, 14  S. aureus and two S. schweitzeri isolates were identified including three MRSA. Genotyping classified the S. aureus isolates into ST8/CC8, ST30/CC30, ST15/ST5875/CC15, ST508/ST5876/CC45, ST121/CC121, ST152/CC152 and ST3961. All the isolates in CC30, CC121, and CC152 were lukS/lukF-PV positive. The MRSA (PVL+) were assigned with CC152. Phylogenetic analysis revealed that the S. schweitzeri isolates were closely related with those from fruit bats (Eidolon helvum) in Nigeria. The differentiation of S. aureus from S. schweitzeri was clearly achieved through MALDI-TOF and PCR. Fomites are not only a reservoir for S. aureus but also for S. schweitzeri that was so far recovered primarily in African wildlife.

Rat liver and kidney post-mitochondrial dysfunction by addition of chronic mixed metal intoxication and hepatorenal wellness mediated by phenolic components from Croton zambiscus leaves

Chronic exposure of mixed-metal intoxication has been associated with prolonged oxidative stress and severe hepatorenal damage. This present study demonstrates the hepatoprotective and renoprotective activity of Croton zambesicus (C-ZAMB) leaves, naturally occurring phenolic compounds against chronic mixed-metal (EOMABRSL) induced toxicity. 0.5 ml of EOMABRSL via oral route induced chronic hepatoxicity and nephrotoxicity on exposure for 98 days (non-withdrawal) and 70 days (withdrawal) by abnormal alteration in the levels of endogenous antioxidants. Moreover, EOMABRSL induced hepatorenal damage by increasing the markers of liver toxicity (ALT, AST, ALP, GGT and bilirubin) and kidney failure (creatinine, urea, uric acid, and renal electrolytes-Na⁺ and K⁺). Both non-withdrawal and withdrawal approaches of EOMABRSL-exposed animals exhibited hepatorenal dysfunctions by increasing the activity of eco-5¹-nucleotidase (5¹ENT) followed by the decreased in the activity of lactate dehydrogenase (LDH)-index of cellular ATP. These results were further supported by the histopathological examination of nephritic cells, hepatocytes and splenocytes, manifested by hepatocellular necrosis, swelling or degeneration of tubular kidney epithelial cells as well as coalescing splenic periarteriolar lymphoid sheaths (PALSs) and lymphoid haemosiderin. The chronic EOMABRSL intoxication was ameliorated by administration of phenolic antioxidants from C-ZAMB leaves. Therefore, our study supports the view that phenolic C-ZAMB leaves may mediate hepatorenal wellness on chronic exposure to mixed-metal intoxication.

Red cell indices and peripheral blood film findings of anti-Psychotic treatment and treatment naïve Psychiatic patients in a tertiary Hospital in Nigeria

Background: The overall burden of morbidity and mortality from psychiatric disorders is on the rise. Holistic approach in the care of this group of patients has become inevitable. There is need for collaboration between psychiatrists and other physicians, laboratory physicians inclusive. Study design: cross sectional descriptive case- control study. Materials and method: A total of 198 patients including controls were recruited for this study. Patients with schizophrenia constituted majority of the respondents, 86.4% of antipsychotic-naïve patients and 90.9% of patients on antipsychotics. A comprehensive medical examination was carried out on every participant. On every sample, automated Full Blood Count was performed using Sysmex2000i and peripheral blood film was made and examined. Result: 51.5% and 47% of anti-psychotropicnaïve patients and patients on anti-psychotic were 18-40 and 41-60 years respectively. Male (57.6%), predominated the anti-psychotic naïve group while female (51.5%) predominated the group on anti-psychotics. Schizophrenia was the diagnosis in the majority of patients, 86.4% and 91% respectively in anti-psychotic naïve and antipsychotic treatment groups. Other diagnoses were depressive illness, substance use disorder and dementia. Of all the subjects, one (1.5%) schizophrenic patients and two (3%) of controls had abnormal haemogram results. For the schizophrenic patient with abnormal results, haematocrit was 12g/dl, MCV of 75fl and MCH of 26pg, while the two controls with abnormal results had only haematocrit deranged with value of 12.3g/d. Neutrophil hypersegmentation was seen on the film of five antipsychotic-naïve patients (7.5%) diagnosed with Schizophrenia and one (1.5%) of the controls. Macrocytosis was only seen in three (4.5%) of the five antipsychotic-naïve patients that had neutrophil hypersegmentation. Conclusion: No significant difference was noted in the Full Blood Counts among the two sets of patients and controls, although there were isolated cases of neutrohil hyperesegmentation and macrocytosis. Bangladesh Journal of Medical Science Vol.18(2) 2019 p.196-205

Effect of Hepatitis B Virus Co-Infection on CD4 Cell Count and Liver Function of HIV Infected Patients

BACKGROUND

Human immunodeficiency virus (HIV) and Hepatitis B virus (HBV) share similar routes of transmission, making it possible for an individual to have a co-infection. HBV infection is well known to be a major cause of chronic liver diseases worldwide. The aim of this study was to determine the prevalence of HBV infection among HIV infected HAART naïve patients and investigate the effect of co-infection on CD4 count and liver function.

STUDY DESIGN

This was a hospital based descriptive cross sectional study of one hundred consecutive therapy-naive HIV-infected individuals. The CD4 count, Hepatitis B surface antigen, Serum albumin, total Protein, and liver enzymes were determined using standard techniques.

RESULTS

The prevalence of HIV and HBV co-infection was 37%. The mean serum ALT and ALP were significantly higher in the co- infected patients (P-values <0.05). The mean CD4 count of the mono infected patients was significantly higher (p-value of 0.014). The mean serum ALT, AST and ALP of mono and co-infected patients with CD4 count<200/µl were significantly higher than those with count ≥ 200 cells/µl. (p-value of <0.01). The mean ALT and AST of the co-infected patients and all patients with CD4 count <200 cells/µl were higher than the normal reference range.

CONCLUSION

Approximately one third of HIV positive patients had hepatitis B virus co-infection. Co-infection and CD4 count <200 cells/µl are likely to result in abnormal ALT and AST. We recommend that co-infected patients and those with CD4 count <200 cells/µl should be given non-hepatotoxic antiretroviral drug.

Effect of hepatitis-B virus co-infection on CD4 cell count and liver function of HIV infected patients

BACKGROUND

Human immunodeficiency virus (HIV) and Hepatitis B virus (HBV) share similar routes of transmission making it possible for an individual to have a co-infection. HBV infection is well known to be a major cause of chronic liver diseases worldwide. The aim of this study was to determine the prevalence of HBV infection among HIV infected HAART naïve patients and investigate the effect of co-infection on CD4 count and liver function.

STUDY DESIGN

This was a hospital based descriptive cross sectional study of one hundred consecutive therapy-naive HIV-infected individuals. The CD4 count, Hepatitis B surface antigen. Serum albumin, total Protein, and liver enzymes were determined using standard techniques.

RESULTS

The prevalence of HIV and HBV co-infection was 37%. The mean serum ALT and ALP were significantly higher in the co-infected patients (P-values <0.05). The mean CD4 count of the mono infected patients was significantly higher (p-value of 0.014). The mean serum ALT, AST and ALP of mono and coinfected patients with CD4 count<200/µl were significantly higher than those with count ≥ 200 cells/µl. (p-value of <0.01). The mean ALT and AST of the co infected patients and all patients with CD4 count <200 cells/µl were higher than the normal reference range.

CONCLUSION

Approximately one third of HIV positive patients had hepatitis B virus co-infection. Co-infection and CD4 count <200 cells/µl are likely to result in abnormal ALT and AST. We recommend those co-infected patients and those with CD4 count <200 cells/µl should be given non-hepatotoxic antiretroviral drug.

Pre-donation screening of blood for transfusion transmissible infections: the gains and the pains - experience at a resource limited blood bank

OBJECTIVE

To determine whether or not pre-donation testing of blood donors affords substantial cost savings without compromise to blood transfusion safety. Pre-donation testing of blood donors for Transfusion Transmissible Infections (TTIs) is done in most developing countries because substantial cost savings are made from resources, materials and man-hours which would have been spent to procure infected blood units. Simple rapid test kits used in pre-donation testing is not as sensitive as the Enzyme Linked Immuno-sorbent Assay (ELISA) method used in post-donation screening in a quality assured manner.

DESIGN

It is a retrospective study where records of pre- and post-donation tests done in donor clinic of University of Ilorin Teaching Hospital, between January and December 2010 were retrieved. All processes and inputs were evaluated and costs calculated for pre-donation testing by simple rapid techniques and post donation screening by ELISA.

RESULTS

5000 prospective donors were tested in the study period. The cost of single rapid Pre-donation testing was less than that of single ELISA Post-donation screen. The cost of double rapid Pre-donation and Post donation ELISA screen exceeded the cost of single post donation ELISA screen. Substantial cost savings were made when single rapid Pre-donation testing is relied on. More blood units were found reactive for the TTIs with the more expensive Post-donation ELISA.

CONCLUSION

Pre-donation testing of blood donors was not cost effective. Although, there is an apparent savings if pre-donation testing is not followed by post-donation ELISA testing, it is done at a compromise to blood transfusion safety.

RISK FACTORS AND SERO-PREVALENCE OF HEPATITIS B SURFACE ANTIGEN AMONG BLOOD DONORS IN UNIVERSITY OF ILORIN TEACHING HOSPITAL, ILORIN, NIGERIA

BACKGROUND

Availability of safe blood and blood products for transfusion is increasingly difficult globally, especially in developing countries because of high prevalence of Transfusion Transmissible Infections.

OBJECTIVES

To determine the prevalence of HBsAg among blood donors and to evaluate the socio-economic, demographic and medical factors associated with its infection.

DESIGN

A prospective study.

SUBJECTS

Three hundred and fifty consecutive blood donors were recruited. 2 ml of venous blood was collected aseptically from the ante-cubital vein and subjected to serological test for HBsAg.

RESULTS

High prevalence rate 10.9% was recorded. All the donors reactive to HBsAg were males (38,100%) with a mean age of 30.7 ± 8.02 years, while 55.3%, 44.7%, 5.3%, 42%, 47.4%, 5.3% of them were single, married, primary school graduate, secondary school graduate, tertiary school graduate and illiterate respectively with 36.8%, 23.7%, 39.5% and 0% been unemployed, civil servants/professionals, skilled artisans and business/petty traders. The most common risk factor was multiple sexual partners 55.3%, followed by extra marital affairs 13.2%, tattooing 10.5%, previous blood transfusion 5.2%, previous surgery 2.6% and sex trading 2.6%.

CONCLUSION

Active public enlightenment programmes and strict blood donation selection criteria need to be put in place in order to provide safe blood and blood products for transfusion.

Prevalence and characteristics of cigarette smokers among undergraduates of the University of Ilorin, Nigeria

BACKGROUND

Smoking control is urgently needed to prevent the epidemic of tobacco-related diseases and deaths in developing countries. This requires data on smoking, especially among vulnerable groups like students. We have surveyed cigarette smoking among undergraduates of the University of Ilorin, in the North Central region of Nigeria.

MATERIALS AND METHODS

This was a questionnaire-based survey among undergraduates of the University of Ilorin. A total of 1800 students were selected by multistage random sampling.

RESULTS

A total of 1754 students (234 medical and 1520 non-medical students) completed the questionnaires. They were 1148 (65.5%) males and 606 (34.5%) females with a mean age of 21.6 ± 3.1 years. The prevalence rate of current smoking was 5.7% (males 7.7%, females 2.0%) and of ever smoking was 17.1% (males 22.9%, females 6.2%). Smoking was more common in non-medical students. Eighty-three (83.8%) of the smokers had already started smoking by their eighteenth birthday. Fifty-one (51.5%) of them smoked ≤ 5 sticks of cigarettes daily. Most of them were influenced into smoking by peer pressure and commercial advertisements. Sixty-seven (67.6%) of them believed that smoking could never have a negative impact on their health status and quality of life and just 39 (39.4%) smokers were willing to quit.

CONCLUSIONS

Despite the low prevalence rate of smoking in the studied population, a majority of them were not willing to quit because of a low perception of the negative effects of smoking on their health and quality of life. Comprehensive antismoking campaigns were urgently needed to control cigarette smoking among University undergraduates in Nigeria.

The discovery of a multi-resistant Staphylococcus haemolyticus clone in the hospital and community environment in south western Nigeria

Among clinically significant isolates of coagulase negative staphylococci, Staphylococcus haemolyticus is ranked second after Staphylococcus epidermidis. It has been associated with septicemia in newborns and various infections in persons with compromised host defenses and implanted foreign bodies. The existence of a multi-resistant Staphylococcus haemolyticus clone was discovered during a study on patients with skin and soft tissue infections at two local health clinics and in a referral hospital in South Western Nigeria. The clonal nature of these strains was determined by antibiotic susceptibility profile and pulsed field gel electrophoresis. This represents the first report of what appears to be a hospital-acquired and transmitted Staphylococcus haemolyticus clone in South Western Nigeria. Careful infection control measures and strain typing are urgently needed to understand species epidemiology and to limit the spread of multi-resistant strains within and beyond healthcare facilities.

Wound infections in two health institutions in Ile-Ife, Nigeria: results of a cohort study

The control of wound infections is increasingly complicated, yet treatment is not always guided by microbiological diagnosis. To describe the distribution of wound infections and causative agents, a prospective, 6-month cohort study involving 102 outpatients was conducted at the University Teaching Hospital and the Health Center in Ile-Ife, Nigeria. Location and type of infected wounds were recorded and bacterial isolates were identified by standard microbiological techniques. Almost half (40%) of all infected wounds were attributed to trauma and, in most cases, located on the extremities. Of the 162 bacterial isolates obtained from wound cultures, 39 were monomicrobial and 55 were polymicrobial; no bacterial isolate was obtained in eight cases. Staphylococcus aureus was the predominant micro-organism (25%), followed by Escherichia coli (12%), Pseudomonas aeruginosa (9%), and Staphylococcus epidermidis (9%). The diversity of micro-organisms and the high incidence of polymicrobic flora in this study give credence to the value of identifying one or more bacterial pathogens from wound cultures. The recognition of causative agents of wound infections can assist wound care practitioners in taking appropriate measures. Continuous dialogue between the microbiology department and wound care practitioners is strongly advised in order to improve treatment outcomes and slow the development of antibiotic-resistant bacteria.

The formulation of an effective topical antibacterial product containing Ocimum gratissimum leaf essential oil

The antibacterial potential of Ocimum gratissimum essential oil was explored. Liquid and semisolid formulations of the oil were designed in a variety of bases for topical antiseptic medication. The products were evaluated by agar diffusion assay against type strains and clinical isolates from boil, wound and pimples. Remarkable antibacterial effects, higher than those of commercial antiseptic products, were demonstrated at 2% Ocimum oil concentration in some bases. The properties of base into which the oil was incorporated affected its activity. It was more effective in hydrophilic bases than in lipophilic bases. Solubilization and microemulsification grossly reduced its activity.

Unusual recovery of animal staphylococci from septic wounds of hospital patients in Ile-Ife, Nigeria

Two Staphylococcus species--Staphylococcus gallinarum and Staphylococcus sciuri--previously known to be of animal origin have been isolated from infected wounds of hospital patients in Ile-Ife, Nigeria. These organisms were non-typable at both RTD and 100 x RTD and did not produce beta-lactamase detectable by the normal methods. Their actual involvement in the infection is not immediately clear, but their resistance to most common antibiotics, in addition to the production of DNase and phosphatase, may be indicating that these species could become important skin contaminants in humans and opportunistic zoonotics.